--- old/src/os/linux/vm/os_linux.cpp Tue Sep 13 12:29:50 2011 +++ /dev/null Tue Sep 13 12:29:27 2011 @@ -1,5531 +0,0 @@ -/* - * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved. - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This code is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 only, as - * published by the Free Software Foundation. - * - * This code is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * version 2 for more details (a copy is included in the LICENSE file that - * accompanied this code). - * - * You should have received a copy of the GNU General Public License version - * 2 along with this work; if not, write to the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. - * - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA - * or visit www.oracle.com if you need additional information or have any - * questions. - * - */ - -# define __STDC_FORMAT_MACROS - -// no precompiled headers -#include "classfile/classLoader.hpp" -#include "classfile/systemDictionary.hpp" -#include "classfile/vmSymbols.hpp" -#include "code/icBuffer.hpp" -#include "code/vtableStubs.hpp" -#include "compiler/compileBroker.hpp" -#include "interpreter/interpreter.hpp" -#include "jvm_linux.h" -#include "memory/allocation.inline.hpp" -#include "memory/filemap.hpp" -#include "mutex_linux.inline.hpp" -#include "oops/oop.inline.hpp" -#include "os_share_linux.hpp" -#include "prims/jniFastGetField.hpp" -#include "prims/jvm.h" -#include "prims/jvm_misc.hpp" -#include "runtime/arguments.hpp" -#include "runtime/extendedPC.hpp" -#include "runtime/globals.hpp" -#include "runtime/interfaceSupport.hpp" -#include "runtime/java.hpp" -#include "runtime/javaCalls.hpp" -#include "runtime/mutexLocker.hpp" -#include "runtime/objectMonitor.hpp" -#include "runtime/osThread.hpp" -#include "runtime/perfMemory.hpp" -#include "runtime/sharedRuntime.hpp" -#include "runtime/statSampler.hpp" -#include "runtime/stubRoutines.hpp" -#include "runtime/threadCritical.hpp" -#include "runtime/timer.hpp" -#include "services/attachListener.hpp" -#include "services/runtimeService.hpp" -#include "thread_linux.inline.hpp" -#include "utilities/decoder.hpp" -#include "utilities/defaultStream.hpp" -#include "utilities/events.hpp" -#include "utilities/growableArray.hpp" -#include "utilities/vmError.hpp" -#ifdef TARGET_ARCH_x86 -# include "assembler_x86.inline.hpp" -# include "nativeInst_x86.hpp" -#endif -#ifdef TARGET_ARCH_sparc -# include "assembler_sparc.inline.hpp" -# include "nativeInst_sparc.hpp" -#endif -#ifdef TARGET_ARCH_zero -# include "assembler_zero.inline.hpp" -# include "nativeInst_zero.hpp" -#endif -#ifdef TARGET_ARCH_arm -# include "assembler_arm.inline.hpp" -# include "nativeInst_arm.hpp" -#endif -#ifdef TARGET_ARCH_ppc -# include "assembler_ppc.inline.hpp" -# include "nativeInst_ppc.hpp" -#endif -#ifdef COMPILER1 -#include "c1/c1_Runtime1.hpp" -#endif -#ifdef COMPILER2 -#include "opto/runtime.hpp" -#endif - -// put OS-includes here -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include -# include - -#define MAX_PATH (2 * K) - -// for timer info max values which include all bits -#define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) -#define SEC_IN_NANOSECS 1000000000LL - -#define LARGEPAGES_BIT (1 << 6) -//////////////////////////////////////////////////////////////////////////////// -// global variables -julong os::Linux::_physical_memory = 0; - -address os::Linux::_initial_thread_stack_bottom = NULL; -uintptr_t os::Linux::_initial_thread_stack_size = 0; - -int (*os::Linux::_clock_gettime)(clockid_t, struct timespec *) = NULL; -int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL; -Mutex* os::Linux::_createThread_lock = NULL; -pthread_t os::Linux::_main_thread; -int os::Linux::_page_size = -1; -bool os::Linux::_is_floating_stack = false; -bool os::Linux::_is_NPTL = false; -bool os::Linux::_supports_fast_thread_cpu_time = false; -const char * os::Linux::_glibc_version = NULL; -const char * os::Linux::_libpthread_version = NULL; - -static jlong initial_time_count=0; - -static int clock_tics_per_sec = 100; - -// For diagnostics to print a message once. see run_periodic_checks -static sigset_t check_signal_done; -static bool check_signals = true;; - -static pid_t _initial_pid = 0; - -/* Signal number used to suspend/resume a thread */ - -/* do not use any signal number less than SIGSEGV, see 4355769 */ -static int SR_signum = SIGUSR2; -sigset_t SR_sigset; - -/* Used to protect dlsym() calls */ -static pthread_mutex_t dl_mutex; - -#ifdef JAVASE_EMBEDDED -class MemNotifyThread: public Thread { - friend class VMStructs; - public: - virtual void run(); - - private: - static MemNotifyThread* _memnotify_thread; - int _fd; - - public: - - // Constructor - MemNotifyThread(int fd); - - // Tester - bool is_memnotify_thread() const { return true; } - - // Printing - char* name() const { return (char*)"Linux MemNotify Thread"; } - - // Returns the single instance of the MemNotifyThread - static MemNotifyThread* memnotify_thread() { return _memnotify_thread; } - - // Create and start the single instance of MemNotifyThread - static void start(); -}; -#endif // JAVASE_EMBEDDED - -// utility functions - -static int SR_initialize(); -static int SR_finalize(); - -julong os::available_memory() { - return Linux::available_memory(); -} - -julong os::Linux::available_memory() { - // values in struct sysinfo are "unsigned long" - struct sysinfo si; - sysinfo(&si); - - return (julong)si.freeram * si.mem_unit; -} - -julong os::physical_memory() { - return Linux::physical_memory(); -} - -julong os::allocatable_physical_memory(julong size) { -#ifdef _LP64 - return size; -#else - julong result = MIN2(size, (julong)3800*M); - if (!is_allocatable(result)) { - // See comments under solaris for alignment considerations - julong reasonable_size = (julong)2*G - 2 * os::vm_page_size(); - result = MIN2(size, reasonable_size); - } - return result; -#endif // _LP64 -} - -//////////////////////////////////////////////////////////////////////////////// -// environment support - -bool os::getenv(const char* name, char* buf, int len) { - const char* val = ::getenv(name); - if (val != NULL && strlen(val) < (size_t)len) { - strcpy(buf, val); - return true; - } - if (len > 0) buf[0] = 0; // return a null string - return false; -} - - -// Return true if user is running as root. - -bool os::have_special_privileges() { - static bool init = false; - static bool privileges = false; - if (!init) { - privileges = (getuid() != geteuid()) || (getgid() != getegid()); - init = true; - } - return privileges; -} - - -#ifndef SYS_gettid -// i386: 224, ia64: 1105, amd64: 186, sparc 143 -#ifdef __ia64__ -#define SYS_gettid 1105 -#elif __i386__ -#define SYS_gettid 224 -#elif __amd64__ -#define SYS_gettid 186 -#elif __sparc__ -#define SYS_gettid 143 -#else -#error define gettid for the arch -#endif -#endif - -// Cpu architecture string -#if defined(ZERO) -static char cpu_arch[] = ZERO_LIBARCH; -#elif defined(IA64) -static char cpu_arch[] = "ia64"; -#elif defined(IA32) -static char cpu_arch[] = "i386"; -#elif defined(AMD64) -static char cpu_arch[] = "amd64"; -#elif defined(ARM) -static char cpu_arch[] = "arm"; -#elif defined(PPC) -static char cpu_arch[] = "ppc"; -#elif defined(SPARC) -# ifdef _LP64 -static char cpu_arch[] = "sparcv9"; -# else -static char cpu_arch[] = "sparc"; -# endif -#else -#error Add appropriate cpu_arch setting -#endif - - -// pid_t gettid() -// -// Returns the kernel thread id of the currently running thread. Kernel -// thread id is used to access /proc. -// -// (Note that getpid() on LinuxThreads returns kernel thread id too; but -// on NPTL, it returns the same pid for all threads, as required by POSIX.) -// -pid_t os::Linux::gettid() { - int rslt = syscall(SYS_gettid); - if (rslt == -1) { - // old kernel, no NPTL support - return getpid(); - } else { - return (pid_t)rslt; - } -} - -// Most versions of linux have a bug where the number of processors are -// determined by looking at the /proc file system. In a chroot environment, -// the system call returns 1. This causes the VM to act as if it is -// a single processor and elide locking (see is_MP() call). -static bool unsafe_chroot_detected = false; -static const char *unstable_chroot_error = "/proc file system not found.\n" - "Java may be unstable running multithreaded in a chroot " - "environment on Linux when /proc filesystem is not mounted."; - -void os::Linux::initialize_system_info() { - set_processor_count(sysconf(_SC_NPROCESSORS_CONF)); - if (processor_count() == 1) { - pid_t pid = os::Linux::gettid(); - char fname[32]; - jio_snprintf(fname, sizeof(fname), "/proc/%d", pid); - FILE *fp = fopen(fname, "r"); - if (fp == NULL) { - unsafe_chroot_detected = true; - } else { - fclose(fp); - } - } - _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE); - assert(processor_count() > 0, "linux error"); -} - -void os::init_system_properties_values() { -// char arch[12]; -// sysinfo(SI_ARCHITECTURE, arch, sizeof(arch)); - - // The next steps are taken in the product version: - // - // Obtain the JAVA_HOME value from the location of libjvm[_g].so. - // This library should be located at: - // /jre/lib//{client|server}/libjvm[_g].so. - // - // If "/jre/lib/" appears at the right place in the path, then we - // assume libjvm[_g].so is installed in a JDK and we use this path. - // - // Otherwise exit with message: "Could not create the Java virtual machine." - // - // The following extra steps are taken in the debugging version: - // - // If "/jre/lib/" does NOT appear at the right place in the path - // instead of exit check for $JAVA_HOME environment variable. - // - // If it is defined and we are able to locate $JAVA_HOME/jre/lib/, - // then we append a fake suffix "hotspot/libjvm[_g].so" to this path so - // it looks like libjvm[_g].so is installed there - // /jre/lib//hotspot/libjvm[_g].so. - // - // Otherwise exit. - // - // Important note: if the location of libjvm.so changes this - // code needs to be changed accordingly. - - // The next few definitions allow the code to be verbatim: -#define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n)) -#define getenv(n) ::getenv(n) - -/* - * See ld(1): - * The linker uses the following search paths to locate required - * shared libraries: - * 1: ... - * ... - * 7: The default directories, normally /lib and /usr/lib. - */ -#if defined(AMD64) || defined(_LP64) && (defined(SPARC) || defined(PPC) || defined(S390)) -#define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib" -#else -#define DEFAULT_LIBPATH "/lib:/usr/lib" -#endif - -#define EXTENSIONS_DIR "/lib/ext" -#define ENDORSED_DIR "/lib/endorsed" -#define REG_DIR "/usr/java/packages" - - { - /* sysclasspath, java_home, dll_dir */ - { - char *home_path; - char *dll_path; - char *pslash; - char buf[MAXPATHLEN]; - os::jvm_path(buf, sizeof(buf)); - - // Found the full path to libjvm.so. - // Now cut the path to /jre if we can. - *(strrchr(buf, '/')) = '\0'; /* get rid of /libjvm.so */ - pslash = strrchr(buf, '/'); - if (pslash != NULL) - *pslash = '\0'; /* get rid of /{client|server|hotspot} */ - dll_path = malloc(strlen(buf) + 1); - if (dll_path == NULL) - return; - strcpy(dll_path, buf); - Arguments::set_dll_dir(dll_path); - - if (pslash != NULL) { - pslash = strrchr(buf, '/'); - if (pslash != NULL) { - *pslash = '\0'; /* get rid of / */ - pslash = strrchr(buf, '/'); - if (pslash != NULL) - *pslash = '\0'; /* get rid of /lib */ - } - } - - home_path = malloc(strlen(buf) + 1); - if (home_path == NULL) - return; - strcpy(home_path, buf); - Arguments::set_java_home(home_path); - - if (!set_boot_path('/', ':')) - return; - } - - /* - * Where to look for native libraries - * - * Note: Due to a legacy implementation, most of the library path - * is set in the launcher. This was to accomodate linking restrictions - * on legacy Linux implementations (which are no longer supported). - * Eventually, all the library path setting will be done here. - * - * However, to prevent the proliferation of improperly built native - * libraries, the new path component /usr/java/packages is added here. - * Eventually, all the library path setting will be done here. - */ - { - char *ld_library_path; - - /* - * Construct the invariant part of ld_library_path. Note that the - * space for the colon and the trailing null are provided by the - * nulls included by the sizeof operator (so actually we allocate - * a byte more than necessary). - */ - ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") + - strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH)); - sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch); - - /* - * Get the user setting of LD_LIBRARY_PATH, and prepended it. It - * should always exist (until the legacy problem cited above is - * addressed). - */ - char *v = getenv("LD_LIBRARY_PATH"); - if (v != NULL) { - char *t = ld_library_path; - /* That's +1 for the colon and +1 for the trailing '\0' */ - ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1); - sprintf(ld_library_path, "%s:%s", v, t); - } - Arguments::set_library_path(ld_library_path); - } - - /* - * Extensions directories. - * - * Note that the space for the colon and the trailing null are provided - * by the nulls included by the sizeof operator (so actually one byte more - * than necessary is allocated). - */ - { - char *buf = malloc(strlen(Arguments::get_java_home()) + - sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR)); - sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR, - Arguments::get_java_home()); - Arguments::set_ext_dirs(buf); - } - - /* Endorsed standards default directory. */ - { - char * buf; - buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR)); - sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home()); - Arguments::set_endorsed_dirs(buf); - } - } - -#undef malloc -#undef getenv -#undef EXTENSIONS_DIR -#undef ENDORSED_DIR - - // Done - return; -} - -//////////////////////////////////////////////////////////////////////////////// -// breakpoint support - -void os::breakpoint() { - BREAKPOINT; -} - -extern "C" void breakpoint() { - // use debugger to set breakpoint here -} - -//////////////////////////////////////////////////////////////////////////////// -// signal support - -debug_only(static bool signal_sets_initialized = false); -static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; - -bool os::Linux::is_sig_ignored(int sig) { - struct sigaction oact; - sigaction(sig, (struct sigaction*)NULL, &oact); - void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) - : CAST_FROM_FN_PTR(void*, oact.sa_handler); - if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) - return true; - else - return false; -} - -void os::Linux::signal_sets_init() { - // Should also have an assertion stating we are still single-threaded. - assert(!signal_sets_initialized, "Already initialized"); - // Fill in signals that are necessarily unblocked for all threads in - // the VM. Currently, we unblock the following signals: - // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden - // by -Xrs (=ReduceSignalUsage)); - // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all - // other threads. The "ReduceSignalUsage" boolean tells us not to alter - // the dispositions or masks wrt these signals. - // Programs embedding the VM that want to use the above signals for their - // own purposes must, at this time, use the "-Xrs" option to prevent - // interference with shutdown hooks and BREAK_SIGNAL thread dumping. - // (See bug 4345157, and other related bugs). - // In reality, though, unblocking these signals is really a nop, since - // these signals are not blocked by default. - sigemptyset(&unblocked_sigs); - sigemptyset(&allowdebug_blocked_sigs); - sigaddset(&unblocked_sigs, SIGILL); - sigaddset(&unblocked_sigs, SIGSEGV); - sigaddset(&unblocked_sigs, SIGBUS); - sigaddset(&unblocked_sigs, SIGFPE); - sigaddset(&unblocked_sigs, SR_signum); - - if (!ReduceSignalUsage) { - if (!os::Linux::is_sig_ignored(SHUTDOWN1_SIGNAL)) { - sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); - sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); - } - if (!os::Linux::is_sig_ignored(SHUTDOWN2_SIGNAL)) { - sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); - sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); - } - if (!os::Linux::is_sig_ignored(SHUTDOWN3_SIGNAL)) { - sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); - sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); - } - } - // Fill in signals that are blocked by all but the VM thread. - sigemptyset(&vm_sigs); - if (!ReduceSignalUsage) - sigaddset(&vm_sigs, BREAK_SIGNAL); - debug_only(signal_sets_initialized = true); - -} - -// These are signals that are unblocked while a thread is running Java. -// (For some reason, they get blocked by default.) -sigset_t* os::Linux::unblocked_signals() { - assert(signal_sets_initialized, "Not initialized"); - return &unblocked_sigs; -} - -// These are the signals that are blocked while a (non-VM) thread is -// running Java. Only the VM thread handles these signals. -sigset_t* os::Linux::vm_signals() { - assert(signal_sets_initialized, "Not initialized"); - return &vm_sigs; -} - -// These are signals that are blocked during cond_wait to allow debugger in -sigset_t* os::Linux::allowdebug_blocked_signals() { - assert(signal_sets_initialized, "Not initialized"); - return &allowdebug_blocked_sigs; -} - -void os::Linux::hotspot_sigmask(Thread* thread) { - - //Save caller's signal mask before setting VM signal mask - sigset_t caller_sigmask; - pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); - - OSThread* osthread = thread->osthread(); - osthread->set_caller_sigmask(caller_sigmask); - - pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL); - - if (!ReduceSignalUsage) { - if (thread->is_VM_thread()) { - // Only the VM thread handles BREAK_SIGNAL ... - pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); - } else { - // ... all other threads block BREAK_SIGNAL - pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); - } - } -} - -////////////////////////////////////////////////////////////////////////////// -// detecting pthread library - -void os::Linux::libpthread_init() { - // Save glibc and pthread version strings. Note that _CS_GNU_LIBC_VERSION - // and _CS_GNU_LIBPTHREAD_VERSION are supported in glibc >= 2.3.2. Use a - // generic name for earlier versions. - // Define macros here so we can build HotSpot on old systems. -# ifndef _CS_GNU_LIBC_VERSION -# define _CS_GNU_LIBC_VERSION 2 -# endif -# ifndef _CS_GNU_LIBPTHREAD_VERSION -# define _CS_GNU_LIBPTHREAD_VERSION 3 -# endif - - size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0); - if (n > 0) { - char *str = (char *)malloc(n); - confstr(_CS_GNU_LIBC_VERSION, str, n); - os::Linux::set_glibc_version(str); - } else { - // _CS_GNU_LIBC_VERSION is not supported, try gnu_get_libc_version() - static char _gnu_libc_version[32]; - jio_snprintf(_gnu_libc_version, sizeof(_gnu_libc_version), - "glibc %s %s", gnu_get_libc_version(), gnu_get_libc_release()); - os::Linux::set_glibc_version(_gnu_libc_version); - } - - n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0); - if (n > 0) { - char *str = (char *)malloc(n); - confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n); - // Vanilla RH-9 (glibc 2.3.2) has a bug that confstr() always tells - // us "NPTL-0.29" even we are running with LinuxThreads. Check if this - // is the case. LinuxThreads has a hard limit on max number of threads. - // So sysconf(_SC_THREAD_THREADS_MAX) will return a positive value. - // On the other hand, NPTL does not have such a limit, sysconf() - // will return -1 and errno is not changed. Check if it is really NPTL. - if (strcmp(os::Linux::glibc_version(), "glibc 2.3.2") == 0 && - strstr(str, "NPTL") && - sysconf(_SC_THREAD_THREADS_MAX) > 0) { - free(str); - os::Linux::set_libpthread_version("linuxthreads"); - } else { - os::Linux::set_libpthread_version(str); - } - } else { - // glibc before 2.3.2 only has LinuxThreads. - os::Linux::set_libpthread_version("linuxthreads"); - } - - if (strstr(libpthread_version(), "NPTL")) { - os::Linux::set_is_NPTL(); - } else { - os::Linux::set_is_LinuxThreads(); - } - - // LinuxThreads have two flavors: floating-stack mode, which allows variable - // stack size; and fixed-stack mode. NPTL is always floating-stack. - if (os::Linux::is_NPTL() || os::Linux::supports_variable_stack_size()) { - os::Linux::set_is_floating_stack(); - } -} - -///////////////////////////////////////////////////////////////////////////// -// thread stack - -// Force Linux kernel to expand current thread stack. If "bottom" is close -// to the stack guard, caller should block all signals. -// -// MAP_GROWSDOWN: -// A special mmap() flag that is used to implement thread stacks. It tells -// kernel that the memory region should extend downwards when needed. This -// allows early versions of LinuxThreads to only mmap the first few pages -// when creating a new thread. Linux kernel will automatically expand thread -// stack as needed (on page faults). -// -// However, because the memory region of a MAP_GROWSDOWN stack can grow on -// demand, if a page fault happens outside an already mapped MAP_GROWSDOWN -// region, it's hard to tell if the fault is due to a legitimate stack -// access or because of reading/writing non-exist memory (e.g. buffer -// overrun). As a rule, if the fault happens below current stack pointer, -// Linux kernel does not expand stack, instead a SIGSEGV is sent to the -// application (see Linux kernel fault.c). -// -// This Linux feature can cause SIGSEGV when VM bangs thread stack for -// stack overflow detection. -// -// Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do -// not use this flag. However, the stack of initial thread is not created -// by pthread, it is still MAP_GROWSDOWN. Also it's possible (though -// unlikely) that user code can create a thread with MAP_GROWSDOWN stack -// and then attach the thread to JVM. -// -// To get around the problem and allow stack banging on Linux, we need to -// manually expand thread stack after receiving the SIGSEGV. -// -// There are two ways to expand thread stack to address "bottom", we used -// both of them in JVM before 1.5: -// 1. adjust stack pointer first so that it is below "bottom", and then -// touch "bottom" -// 2. mmap() the page in question -// -// Now alternate signal stack is gone, it's harder to use 2. For instance, -// if current sp is already near the lower end of page 101, and we need to -// call mmap() to map page 100, it is possible that part of the mmap() frame -// will be placed in page 100. When page 100 is mapped, it is zero-filled. -// That will destroy the mmap() frame and cause VM to crash. -// -// The following code works by adjusting sp first, then accessing the "bottom" -// page to force a page fault. Linux kernel will then automatically expand the -// stack mapping. -// -// _expand_stack_to() assumes its frame size is less than page size, which -// should always be true if the function is not inlined. - -#if __GNUC__ < 3 // gcc 2.x does not support noinline attribute -#define NOINLINE -#else -#define NOINLINE __attribute__ ((noinline)) -#endif - -static void _expand_stack_to(address bottom) NOINLINE; - -static void _expand_stack_to(address bottom) { - address sp; - size_t size; - volatile char *p; - - // Adjust bottom to point to the largest address within the same page, it - // gives us a one-page buffer if alloca() allocates slightly more memory. - bottom = (address)align_size_down((uintptr_t)bottom, os::Linux::page_size()); - bottom += os::Linux::page_size() - 1; - - // sp might be slightly above current stack pointer; if that's the case, we - // will alloca() a little more space than necessary, which is OK. Don't use - // os::current_stack_pointer(), as its result can be slightly below current - // stack pointer, causing us to not alloca enough to reach "bottom". - sp = (address)&sp; - - if (sp > bottom) { - size = sp - bottom; - p = (volatile char *)alloca(size); - assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?"); - p[0] = '\0'; - } -} - -bool os::Linux::manually_expand_stack(JavaThread * t, address addr) { - assert(t!=NULL, "just checking"); - assert(t->osthread()->expanding_stack(), "expand should be set"); - assert(t->stack_base() != NULL, "stack_base was not initialized"); - - if (addr < t->stack_base() && addr >= t->stack_yellow_zone_base()) { - sigset_t mask_all, old_sigset; - sigfillset(&mask_all); - pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset); - _expand_stack_to(addr); - pthread_sigmask(SIG_SETMASK, &old_sigset, NULL); - return true; - } - return false; -} - -////////////////////////////////////////////////////////////////////////////// -// create new thread - -static address highest_vm_reserved_address(); - -// check if it's safe to start a new thread -static bool _thread_safety_check(Thread* thread) { - if (os::Linux::is_LinuxThreads() && !os::Linux::is_floating_stack()) { - // Fixed stack LinuxThreads (SuSE Linux/x86, and some versions of Redhat) - // Heap is mmap'ed at lower end of memory space. Thread stacks are - // allocated (MAP_FIXED) from high address space. Every thread stack - // occupies a fixed size slot (usually 2Mbytes, but user can change - // it to other values if they rebuild LinuxThreads). - // - // Problem with MAP_FIXED is that mmap() can still succeed even part of - // the memory region has already been mmap'ed. That means if we have too - // many threads and/or very large heap, eventually thread stack will - // collide with heap. - // - // Here we try to prevent heap/stack collision by comparing current - // stack bottom with the highest address that has been mmap'ed by JVM - // plus a safety margin for memory maps created by native code. - // - // This feature can be disabled by setting ThreadSafetyMargin to 0 - // - if (ThreadSafetyMargin > 0) { - address stack_bottom = os::current_stack_base() - os::current_stack_size(); - - // not safe if our stack extends below the safety margin - return stack_bottom - ThreadSafetyMargin >= highest_vm_reserved_address(); - } else { - return true; - } - } else { - // Floating stack LinuxThreads or NPTL: - // Unlike fixed stack LinuxThreads, thread stacks are not MAP_FIXED. When - // there's not enough space left, pthread_create() will fail. If we come - // here, that means enough space has been reserved for stack. - return true; - } -} - -// Thread start routine for all newly created threads -static void *java_start(Thread *thread) { - // Try to randomize the cache line index of hot stack frames. - // This helps when threads of the same stack traces evict each other's - // cache lines. The threads can be either from the same JVM instance, or - // from different JVM instances. The benefit is especially true for - // processors with hyperthreading technology. - static int counter = 0; - int pid = os::current_process_id(); - alloca(((pid ^ counter++) & 7) * 128); - - ThreadLocalStorage::set_thread(thread); - - OSThread* osthread = thread->osthread(); - Monitor* sync = osthread->startThread_lock(); - - // non floating stack LinuxThreads needs extra check, see above - if (!_thread_safety_check(thread)) { - // notify parent thread - MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); - osthread->set_state(ZOMBIE); - sync->notify_all(); - return NULL; - } - - // thread_id is kernel thread id (similar to Solaris LWP id) - osthread->set_thread_id(os::Linux::gettid()); - - if (UseNUMA) { - int lgrp_id = os::numa_get_group_id(); - if (lgrp_id != -1) { - thread->set_lgrp_id(lgrp_id); - } - } - // initialize signal mask for this thread - os::Linux::hotspot_sigmask(thread); - - // initialize floating point control register - os::Linux::init_thread_fpu_state(); - - // handshaking with parent thread - { - MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); - - // notify parent thread - osthread->set_state(INITIALIZED); - sync->notify_all(); - - // wait until os::start_thread() - while (osthread->get_state() == INITIALIZED) { - sync->wait(Mutex::_no_safepoint_check_flag); - } - } - - // call one more level start routine - thread->run(); - - return 0; -} - -bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { - assert(thread->osthread() == NULL, "caller responsible"); - - // Allocate the OSThread object - OSThread* osthread = new OSThread(NULL, NULL); - if (osthread == NULL) { - return false; - } - - // set the correct thread state - osthread->set_thread_type(thr_type); - - // Initial state is ALLOCATED but not INITIALIZED - osthread->set_state(ALLOCATED); - - thread->set_osthread(osthread); - - // init thread attributes - pthread_attr_t attr; - pthread_attr_init(&attr); - pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); - - // stack size - if (os::Linux::supports_variable_stack_size()) { - // calculate stack size if it's not specified by caller - if (stack_size == 0) { - stack_size = os::Linux::default_stack_size(thr_type); - - switch (thr_type) { - case os::java_thread: - // Java threads use ThreadStackSize which default value can be - // changed with the flag -Xss - assert (JavaThread::stack_size_at_create() > 0, "this should be set"); - stack_size = JavaThread::stack_size_at_create(); - break; - case os::compiler_thread: - if (CompilerThreadStackSize > 0) { - stack_size = (size_t)(CompilerThreadStackSize * K); - break; - } // else fall through: - // use VMThreadStackSize if CompilerThreadStackSize is not defined - case os::vm_thread: - case os::pgc_thread: - case os::cgc_thread: - case os::watcher_thread: - if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); - break; - } - } - - stack_size = MAX2(stack_size, os::Linux::min_stack_allowed); - pthread_attr_setstacksize(&attr, stack_size); - } else { - // let pthread_create() pick the default value. - } - - // glibc guard page - pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type)); - - ThreadState state; - - { - // Serialize thread creation if we are running with fixed stack LinuxThreads - bool lock = os::Linux::is_LinuxThreads() && !os::Linux::is_floating_stack(); - if (lock) { - os::Linux::createThread_lock()->lock_without_safepoint_check(); - } - - pthread_t tid; - int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); - - pthread_attr_destroy(&attr); - - if (ret != 0) { - if (PrintMiscellaneous && (Verbose || WizardMode)) { - perror("pthread_create()"); - } - // Need to clean up stuff we've allocated so far - thread->set_osthread(NULL); - delete osthread; - if (lock) os::Linux::createThread_lock()->unlock(); - return false; - } - - // Store pthread info into the OSThread - osthread->set_pthread_id(tid); - - // Wait until child thread is either initialized or aborted - { - Monitor* sync_with_child = osthread->startThread_lock(); - MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); - while ((state = osthread->get_state()) == ALLOCATED) { - sync_with_child->wait(Mutex::_no_safepoint_check_flag); - } - } - - if (lock) { - os::Linux::createThread_lock()->unlock(); - } - } - - // Aborted due to thread limit being reached - if (state == ZOMBIE) { - thread->set_osthread(NULL); - delete osthread; - return false; - } - - // The thread is returned suspended (in state INITIALIZED), - // and is started higher up in the call chain - assert(state == INITIALIZED, "race condition"); - return true; -} - -///////////////////////////////////////////////////////////////////////////// -// attach existing thread - -// bootstrap the main thread -bool os::create_main_thread(JavaThread* thread) { - assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread"); - return create_attached_thread(thread); -} - -bool os::create_attached_thread(JavaThread* thread) { -#ifdef ASSERT - thread->verify_not_published(); -#endif - - // Allocate the OSThread object - OSThread* osthread = new OSThread(NULL, NULL); - - if (osthread == NULL) { - return false; - } - - // Store pthread info into the OSThread - osthread->set_thread_id(os::Linux::gettid()); - osthread->set_pthread_id(::pthread_self()); - - // initialize floating point control register - os::Linux::init_thread_fpu_state(); - - // Initial thread state is RUNNABLE - osthread->set_state(RUNNABLE); - - thread->set_osthread(osthread); - - if (UseNUMA) { - int lgrp_id = os::numa_get_group_id(); - if (lgrp_id != -1) { - thread->set_lgrp_id(lgrp_id); - } - } - - if (os::Linux::is_initial_thread()) { - // If current thread is initial thread, its stack is mapped on demand, - // see notes about MAP_GROWSDOWN. Here we try to force kernel to map - // the entire stack region to avoid SEGV in stack banging. - // It is also useful to get around the heap-stack-gap problem on SuSE - // kernel (see 4821821 for details). We first expand stack to the top - // of yellow zone, then enable stack yellow zone (order is significant, - // enabling yellow zone first will crash JVM on SuSE Linux), so there - // is no gap between the last two virtual memory regions. - - JavaThread *jt = (JavaThread *)thread; - address addr = jt->stack_yellow_zone_base(); - assert(addr != NULL, "initialization problem?"); - assert(jt->stack_available(addr) > 0, "stack guard should not be enabled"); - - osthread->set_expanding_stack(); - os::Linux::manually_expand_stack(jt, addr); - osthread->clear_expanding_stack(); - } - - // initialize signal mask for this thread - // and save the caller's signal mask - os::Linux::hotspot_sigmask(thread); - - return true; -} - -void os::pd_start_thread(Thread* thread) { - OSThread * osthread = thread->osthread(); - assert(osthread->get_state() != INITIALIZED, "just checking"); - Monitor* sync_with_child = osthread->startThread_lock(); - MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); - sync_with_child->notify(); -} - -// Free Linux resources related to the OSThread -void os::free_thread(OSThread* osthread) { - assert(osthread != NULL, "osthread not set"); - - if (Thread::current()->osthread() == osthread) { - // Restore caller's signal mask - sigset_t sigmask = osthread->caller_sigmask(); - pthread_sigmask(SIG_SETMASK, &sigmask, NULL); - } - - delete osthread; -} - -////////////////////////////////////////////////////////////////////////////// -// thread local storage - -int os::allocate_thread_local_storage() { - pthread_key_t key; - int rslt = pthread_key_create(&key, NULL); - assert(rslt == 0, "cannot allocate thread local storage"); - return (int)key; -} - -// Note: This is currently not used by VM, as we don't destroy TLS key -// on VM exit. -void os::free_thread_local_storage(int index) { - int rslt = pthread_key_delete((pthread_key_t)index); - assert(rslt == 0, "invalid index"); -} - -void os::thread_local_storage_at_put(int index, void* value) { - int rslt = pthread_setspecific((pthread_key_t)index, value); - assert(rslt == 0, "pthread_setspecific failed"); -} - -extern "C" Thread* get_thread() { - return ThreadLocalStorage::thread(); -} - -////////////////////////////////////////////////////////////////////////////// -// initial thread - -// Check if current thread is the initial thread, similar to Solaris thr_main. -bool os::Linux::is_initial_thread(void) { - char dummy; - // If called before init complete, thread stack bottom will be null. - // Can be called if fatal error occurs before initialization. - if (initial_thread_stack_bottom() == NULL) return false; - assert(initial_thread_stack_bottom() != NULL && - initial_thread_stack_size() != 0, - "os::init did not locate initial thread's stack region"); - if ((address)&dummy >= initial_thread_stack_bottom() && - (address)&dummy < initial_thread_stack_bottom() + initial_thread_stack_size()) - return true; - else return false; -} - -// Find the virtual memory area that contains addr -static bool find_vma(address addr, address* vma_low, address* vma_high) { - FILE *fp = fopen("/proc/self/maps", "r"); - if (fp) { - address low, high; - while (!feof(fp)) { - if (fscanf(fp, "%p-%p", &low, &high) == 2) { - if (low <= addr && addr < high) { - if (vma_low) *vma_low = low; - if (vma_high) *vma_high = high; - fclose (fp); - return true; - } - } - for (;;) { - int ch = fgetc(fp); - if (ch == EOF || ch == (int)'\n') break; - } - } - fclose(fp); - } - return false; -} - -// Locate initial thread stack. This special handling of initial thread stack -// is needed because pthread_getattr_np() on most (all?) Linux distros returns -// bogus value for initial thread. -void os::Linux::capture_initial_stack(size_t max_size) { - // stack size is the easy part, get it from RLIMIT_STACK - size_t stack_size; - struct rlimit rlim; - getrlimit(RLIMIT_STACK, &rlim); - stack_size = rlim.rlim_cur; - - // 6308388: a bug in ld.so will relocate its own .data section to the - // lower end of primordial stack; reduce ulimit -s value a little bit - // so we won't install guard page on ld.so's data section. - stack_size -= 2 * page_size(); - - // 4441425: avoid crash with "unlimited" stack size on SuSE 7.1 or Redhat - // 7.1, in both cases we will get 2G in return value. - // 4466587: glibc 2.2.x compiled w/o "--enable-kernel=2.4.0" (RH 7.0, - // SuSE 7.2, Debian) can not handle alternate signal stack correctly - // for initial thread if its stack size exceeds 6M. Cap it at 2M, - // in case other parts in glibc still assumes 2M max stack size. - // FIXME: alt signal stack is gone, maybe we can relax this constraint? -#ifndef IA64 - if (stack_size > 2 * K * K) stack_size = 2 * K * K; -#else - // Problem still exists RH7.2 (IA64 anyway) but 2MB is a little small - if (stack_size > 4 * K * K) stack_size = 4 * K * K; -#endif - - // Try to figure out where the stack base (top) is. This is harder. - // - // When an application is started, glibc saves the initial stack pointer in - // a global variable "__libc_stack_end", which is then used by system - // libraries. __libc_stack_end should be pretty close to stack top. The - // variable is available since the very early days. However, because it is - // a private interface, it could disappear in the future. - // - // Linux kernel saves start_stack information in /proc//stat. Similar - // to __libc_stack_end, it is very close to stack top, but isn't the real - // stack top. Note that /proc may not exist if VM is running as a chroot - // program, so reading /proc//stat could fail. Also the contents of - // /proc//stat could change in the future (though unlikely). - // - // We try __libc_stack_end first. If that doesn't work, look for - // /proc//stat. If neither of them works, we use current stack pointer - // as a hint, which should work well in most cases. - - uintptr_t stack_start; - - // try __libc_stack_end first - uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end"); - if (p && *p) { - stack_start = *p; - } else { - // see if we can get the start_stack field from /proc/self/stat - FILE *fp; - int pid; - char state; - int ppid; - int pgrp; - int session; - int nr; - int tpgrp; - unsigned long flags; - unsigned long minflt; - unsigned long cminflt; - unsigned long majflt; - unsigned long cmajflt; - unsigned long utime; - unsigned long stime; - long cutime; - long cstime; - long prio; - long nice; - long junk; - long it_real; - uintptr_t start; - uintptr_t vsize; - intptr_t rss; - uintptr_t rsslim; - uintptr_t scodes; - uintptr_t ecode; - int i; - - // Figure what the primordial thread stack base is. Code is inspired - // by email from Hans Boehm. /proc/self/stat begins with current pid, - // followed by command name surrounded by parentheses, state, etc. - char stat[2048]; - int statlen; - - fp = fopen("/proc/self/stat", "r"); - if (fp) { - statlen = fread(stat, 1, 2047, fp); - stat[statlen] = '\0'; - fclose(fp); - - // Skip pid and the command string. Note that we could be dealing with - // weird command names, e.g. user could decide to rename java launcher - // to "java 1.4.2 :)", then the stat file would look like - // 1234 (java 1.4.2 :)) R ... ... - // We don't really need to know the command string, just find the last - // occurrence of ")" and then start parsing from there. See bug 4726580. - char * s = strrchr(stat, ')'); - - i = 0; - if (s) { - // Skip blank chars - do s++; while (isspace(*s)); - -#define _UFM UINTX_FORMAT -#define _DFM INTX_FORMAT - - /* 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 */ - /* 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 */ - i = sscanf(s, "%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld " _UFM _UFM _DFM _UFM _UFM _UFM _UFM, - &state, /* 3 %c */ - &ppid, /* 4 %d */ - &pgrp, /* 5 %d */ - &session, /* 6 %d */ - &nr, /* 7 %d */ - &tpgrp, /* 8 %d */ - &flags, /* 9 %lu */ - &minflt, /* 10 %lu */ - &cminflt, /* 11 %lu */ - &majflt, /* 12 %lu */ - &cmajflt, /* 13 %lu */ - &utime, /* 14 %lu */ - &stime, /* 15 %lu */ - &cutime, /* 16 %ld */ - &cstime, /* 17 %ld */ - &prio, /* 18 %ld */ - &nice, /* 19 %ld */ - &junk, /* 20 %ld */ - &it_real, /* 21 %ld */ - &start, /* 22 UINTX_FORMAT */ - &vsize, /* 23 UINTX_FORMAT */ - &rss, /* 24 INTX_FORMAT */ - &rsslim, /* 25 UINTX_FORMAT */ - &scodes, /* 26 UINTX_FORMAT */ - &ecode, /* 27 UINTX_FORMAT */ - &stack_start); /* 28 UINTX_FORMAT */ - } - -#undef _UFM -#undef _DFM - - if (i != 28 - 2) { - assert(false, "Bad conversion from /proc/self/stat"); - // product mode - assume we are the initial thread, good luck in the - // embedded case. - warning("Can't detect initial thread stack location - bad conversion"); - stack_start = (uintptr_t) &rlim; - } - } else { - // For some reason we can't open /proc/self/stat (for example, running on - // FreeBSD with a Linux emulator, or inside chroot), this should work for - // most cases, so don't abort: - warning("Can't detect initial thread stack location - no /proc/self/stat"); - stack_start = (uintptr_t) &rlim; - } - } - - // Now we have a pointer (stack_start) very close to the stack top, the - // next thing to do is to figure out the exact location of stack top. We - // can find out the virtual memory area that contains stack_start by - // reading /proc/self/maps, it should be the last vma in /proc/self/maps, - // and its upper limit is the real stack top. (again, this would fail if - // running inside chroot, because /proc may not exist.) - - uintptr_t stack_top; - address low, high; - if (find_vma((address)stack_start, &low, &high)) { - // success, "high" is the true stack top. (ignore "low", because initial - // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.) - stack_top = (uintptr_t)high; - } else { - // failed, likely because /proc/self/maps does not exist - warning("Can't detect initial thread stack location - find_vma failed"); - // best effort: stack_start is normally within a few pages below the real - // stack top, use it as stack top, and reduce stack size so we won't put - // guard page outside stack. - stack_top = stack_start; - stack_size -= 16 * page_size(); - } - - // stack_top could be partially down the page so align it - stack_top = align_size_up(stack_top, page_size()); - - if (max_size && stack_size > max_size) { - _initial_thread_stack_size = max_size; - } else { - _initial_thread_stack_size = stack_size; - } - - _initial_thread_stack_size = align_size_down(_initial_thread_stack_size, page_size()); - _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size; -} - -//////////////////////////////////////////////////////////////////////////////// -// time support - -// Time since start-up in seconds to a fine granularity. -// Used by VMSelfDestructTimer and the MemProfiler. -double os::elapsedTime() { - - return (double)(os::elapsed_counter()) * 0.000001; -} - -jlong os::elapsed_counter() { - timeval time; - int status = gettimeofday(&time, NULL); - return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count; -} - -jlong os::elapsed_frequency() { - return (1000 * 1000); -} - -// For now, we say that linux does not support vtime. I have no idea -// whether it can actually be made to (DLD, 9/13/05). - -bool os::supports_vtime() { return false; } -bool os::enable_vtime() { return false; } -bool os::vtime_enabled() { return false; } -double os::elapsedVTime() { - // better than nothing, but not much - return elapsedTime(); -} - -jlong os::javaTimeMillis() { - timeval time; - int status = gettimeofday(&time, NULL); - assert(status != -1, "linux error"); - return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); -} - -#ifndef CLOCK_MONOTONIC -#define CLOCK_MONOTONIC (1) -#endif - -void os::Linux::clock_init() { - // we do dlopen's in this particular order due to bug in linux - // dynamical loader (see 6348968) leading to crash on exit - void* handle = dlopen("librt.so.1", RTLD_LAZY); - if (handle == NULL) { - handle = dlopen("librt.so", RTLD_LAZY); - } - - if (handle) { - int (*clock_getres_func)(clockid_t, struct timespec*) = - (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres"); - int (*clock_gettime_func)(clockid_t, struct timespec*) = - (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime"); - if (clock_getres_func && clock_gettime_func) { - // See if monotonic clock is supported by the kernel. Note that some - // early implementations simply return kernel jiffies (updated every - // 1/100 or 1/1000 second). It would be bad to use such a low res clock - // for nano time (though the monotonic property is still nice to have). - // It's fixed in newer kernels, however clock_getres() still returns - // 1/HZ. We check if clock_getres() works, but will ignore its reported - // resolution for now. Hopefully as people move to new kernels, this - // won't be a problem. - struct timespec res; - struct timespec tp; - if (clock_getres_func (CLOCK_MONOTONIC, &res) == 0 && - clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) { - // yes, monotonic clock is supported - _clock_gettime = clock_gettime_func; - } else { - // close librt if there is no monotonic clock - dlclose(handle); - } - } - } -} - -#ifndef SYS_clock_getres - -#if defined(IA32) || defined(AMD64) -#define SYS_clock_getres IA32_ONLY(266) AMD64_ONLY(229) -#define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) -#else -#warning "SYS_clock_getres not defined for this platform, disabling fast_thread_cpu_time" -#define sys_clock_getres(x,y) -1 -#endif - -#else -#define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) -#endif - -void os::Linux::fast_thread_clock_init() { - if (!UseLinuxPosixThreadCPUClocks) { - return; - } - clockid_t clockid; - struct timespec tp; - int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) = - (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid"); - - // Switch to using fast clocks for thread cpu time if - // the sys_clock_getres() returns 0 error code. - // Note, that some kernels may support the current thread - // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks - // returned by the pthread_getcpuclockid(). - // If the fast Posix clocks are supported then the sys_clock_getres() - // must return at least tp.tv_sec == 0 which means a resolution - // better than 1 sec. This is extra check for reliability. - - if(pthread_getcpuclockid_func && - pthread_getcpuclockid_func(_main_thread, &clockid) == 0 && - sys_clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) { - - _supports_fast_thread_cpu_time = true; - _pthread_getcpuclockid = pthread_getcpuclockid_func; - } -} - -jlong os::javaTimeNanos() { - if (Linux::supports_monotonic_clock()) { - struct timespec tp; - int status = Linux::clock_gettime(CLOCK_MONOTONIC, &tp); - assert(status == 0, "gettime error"); - jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); - return result; - } else { - timeval time; - int status = gettimeofday(&time, NULL); - assert(status != -1, "linux error"); - jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); - return 1000 * usecs; - } -} - -void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { - if (Linux::supports_monotonic_clock()) { - info_ptr->max_value = ALL_64_BITS; - - // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past - info_ptr->may_skip_backward = false; // not subject to resetting or drifting - info_ptr->may_skip_forward = false; // not subject to resetting or drifting - } else { - // gettimeofday - based on time in seconds since the Epoch thus does not wrap - info_ptr->max_value = ALL_64_BITS; - - // gettimeofday is a real time clock so it skips - info_ptr->may_skip_backward = true; - info_ptr->may_skip_forward = true; - } - - info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time -} - -// Return the real, user, and system times in seconds from an -// arbitrary fixed point in the past. -bool os::getTimesSecs(double* process_real_time, - double* process_user_time, - double* process_system_time) { - struct tms ticks; - clock_t real_ticks = times(&ticks); - - if (real_ticks == (clock_t) (-1)) { - return false; - } else { - double ticks_per_second = (double) clock_tics_per_sec; - *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; - *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; - *process_real_time = ((double) real_ticks) / ticks_per_second; - - return true; - } -} - - -char * os::local_time_string(char *buf, size_t buflen) { - struct tm t; - time_t long_time; - time(&long_time); - localtime_r(&long_time, &t); - jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", - t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, - t.tm_hour, t.tm_min, t.tm_sec); - return buf; -} - -struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { - return localtime_r(clock, res); -} - -//////////////////////////////////////////////////////////////////////////////// -// runtime exit support - -// Note: os::shutdown() might be called very early during initialization, or -// called from signal handler. Before adding something to os::shutdown(), make -// sure it is async-safe and can handle partially initialized VM. -void os::shutdown() { - - // allow PerfMemory to attempt cleanup of any persistent resources - perfMemory_exit(); - - // needs to remove object in file system - AttachListener::abort(); - - // flush buffered output, finish log files - ostream_abort(); - - // Check for abort hook - abort_hook_t abort_hook = Arguments::abort_hook(); - if (abort_hook != NULL) { - abort_hook(); - } - -} - -// Note: os::abort() might be called very early during initialization, or -// called from signal handler. Before adding something to os::abort(), make -// sure it is async-safe and can handle partially initialized VM. -void os::abort(bool dump_core) { - os::shutdown(); - if (dump_core) { -#ifndef PRODUCT - fdStream out(defaultStream::output_fd()); - out.print_raw("Current thread is "); - char buf[16]; - jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); - out.print_raw_cr(buf); - out.print_raw_cr("Dumping core ..."); -#endif - ::abort(); // dump core - } - - ::exit(1); -} - -// Die immediately, no exit hook, no abort hook, no cleanup. -void os::die() { - // _exit() on LinuxThreads only kills current thread - ::abort(); -} - -// unused on linux for now. -void os::set_error_file(const char *logfile) {} - - -// This method is a copy of JDK's sysGetLastErrorString -// from src/solaris/hpi/src/system_md.c - -size_t os::lasterror(char *buf, size_t len) { - - if (errno == 0) return 0; - - const char *s = ::strerror(errno); - size_t n = ::strlen(s); - if (n >= len) { - n = len - 1; - } - ::strncpy(buf, s, n); - buf[n] = '\0'; - return n; -} - -intx os::current_thread_id() { return (intx)pthread_self(); } -int os::current_process_id() { - - // Under the old linux thread library, linux gives each thread - // its own process id. Because of this each thread will return - // a different pid if this method were to return the result - // of getpid(2). Linux provides no api that returns the pid - // of the launcher thread for the vm. This implementation - // returns a unique pid, the pid of the launcher thread - // that starts the vm 'process'. - - // Under the NPTL, getpid() returns the same pid as the - // launcher thread rather than a unique pid per thread. - // Use gettid() if you want the old pre NPTL behaviour. - - // if you are looking for the result of a call to getpid() that - // returns a unique pid for the calling thread, then look at the - // OSThread::thread_id() method in osThread_linux.hpp file - - return (int)(_initial_pid ? _initial_pid : getpid()); -} - -// DLL functions - -const char* os::dll_file_extension() { return ".so"; } - -// This must be hard coded because it's the system's temporary -// directory not the java application's temp directory, ala java.io.tmpdir. -const char* os::get_temp_directory() { return "/tmp"; } - -static bool file_exists(const char* filename) { - struct stat statbuf; - if (filename == NULL || strlen(filename) == 0) { - return false; - } - return os::stat(filename, &statbuf) == 0; -} - -void os::dll_build_name(char* buffer, size_t buflen, - const char* pname, const char* fname) { - // Copied from libhpi - const size_t pnamelen = pname ? strlen(pname) : 0; - - // Quietly truncate on buffer overflow. Should be an error. - if (pnamelen + strlen(fname) + 10 > (size_t) buflen) { - *buffer = '\0'; - return; - } - - if (pnamelen == 0) { - snprintf(buffer, buflen, "lib%s.so", fname); - } else if (strchr(pname, *os::path_separator()) != NULL) { - int n; - char** pelements = split_path(pname, &n); - for (int i = 0 ; i < n ; i++) { - // Really shouldn't be NULL, but check can't hurt - if (pelements[i] == NULL || strlen(pelements[i]) == 0) { - continue; // skip the empty path values - } - snprintf(buffer, buflen, "%s/lib%s.so", pelements[i], fname); - if (file_exists(buffer)) { - break; - } - } - // release the storage - for (int i = 0 ; i < n ; i++) { - if (pelements[i] != NULL) { - FREE_C_HEAP_ARRAY(char, pelements[i]); - } - } - if (pelements != NULL) { - FREE_C_HEAP_ARRAY(char*, pelements); - } - } else { - snprintf(buffer, buflen, "%s/lib%s.so", pname, fname); - } -} - -const char* os::get_current_directory(char *buf, int buflen) { - return getcwd(buf, buflen); -} - -// check if addr is inside libjvm[_g].so -bool os::address_is_in_vm(address addr) { - static address libjvm_base_addr; - Dl_info dlinfo; - - if (libjvm_base_addr == NULL) { - dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo); - libjvm_base_addr = (address)dlinfo.dli_fbase; - assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); - } - - if (dladdr((void *)addr, &dlinfo)) { - if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; - } - - return false; -} - -bool os::dll_address_to_function_name(address addr, char *buf, - int buflen, int *offset) { - Dl_info dlinfo; - - if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) { - if (buf != NULL) { - if(!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) { - jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); - } - } - if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; - return true; - } else if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != 0) { - if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), - dlinfo.dli_fname, buf, buflen, offset) == Decoder::no_error) { - return true; - } - } - - if (buf != NULL) buf[0] = '\0'; - if (offset != NULL) *offset = -1; - return false; -} - -struct _address_to_library_name { - address addr; // input : memory address - size_t buflen; // size of fname - char* fname; // output: library name - address base; // library base addr -}; - -static int address_to_library_name_callback(struct dl_phdr_info *info, - size_t size, void *data) { - int i; - bool found = false; - address libbase = NULL; - struct _address_to_library_name * d = (struct _address_to_library_name *)data; - - // iterate through all loadable segments - for (i = 0; i < info->dlpi_phnum; i++) { - address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); - if (info->dlpi_phdr[i].p_type == PT_LOAD) { - // base address of a library is the lowest address of its loaded - // segments. - if (libbase == NULL || libbase > segbase) { - libbase = segbase; - } - // see if 'addr' is within current segment - if (segbase <= d->addr && - d->addr < segbase + info->dlpi_phdr[i].p_memsz) { - found = true; - } - } - } - - // dlpi_name is NULL or empty if the ELF file is executable, return 0 - // so dll_address_to_library_name() can fall through to use dladdr() which - // can figure out executable name from argv[0]. - if (found && info->dlpi_name && info->dlpi_name[0]) { - d->base = libbase; - if (d->fname) { - jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name); - } - return 1; - } - return 0; -} - -bool os::dll_address_to_library_name(address addr, char* buf, - int buflen, int* offset) { - Dl_info dlinfo; - struct _address_to_library_name data; - - // There is a bug in old glibc dladdr() implementation that it could resolve - // to wrong library name if the .so file has a base address != NULL. Here - // we iterate through the program headers of all loaded libraries to find - // out which library 'addr' really belongs to. This workaround can be - // removed once the minimum requirement for glibc is moved to 2.3.x. - data.addr = addr; - data.fname = buf; - data.buflen = buflen; - data.base = NULL; - int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data); - - if (rslt) { - // buf already contains library name - if (offset) *offset = addr - data.base; - return true; - } else if (dladdr((void*)addr, &dlinfo)){ - if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); - if (offset) *offset = addr - (address)dlinfo.dli_fbase; - return true; - } else { - if (buf) buf[0] = '\0'; - if (offset) *offset = -1; - return false; - } -} - - // Loads .dll/.so and - // in case of error it checks if .dll/.so was built for the - // same architecture as Hotspot is running on - -void * os::dll_load(const char *filename, char *ebuf, int ebuflen) -{ - void * result= ::dlopen(filename, RTLD_LAZY); - if (result != NULL) { - // Successful loading - return result; - } - - Elf32_Ehdr elf_head; - - // Read system error message into ebuf - // It may or may not be overwritten below - ::strncpy(ebuf, ::dlerror(), ebuflen-1); - ebuf[ebuflen-1]='\0'; - int diag_msg_max_length=ebuflen-strlen(ebuf); - char* diag_msg_buf=ebuf+strlen(ebuf); - - if (diag_msg_max_length==0) { - // No more space in ebuf for additional diagnostics message - return NULL; - } - - - int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); - - if (file_descriptor < 0) { - // Can't open library, report dlerror() message - return NULL; - } - - bool failed_to_read_elf_head= - (sizeof(elf_head)!= - (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ; - - ::close(file_descriptor); - if (failed_to_read_elf_head) { - // file i/o error - report dlerror() msg - return NULL; - } - - typedef struct { - Elf32_Half code; // Actual value as defined in elf.h - Elf32_Half compat_class; // Compatibility of archs at VM's sense - char elf_class; // 32 or 64 bit - char endianess; // MSB or LSB - char* name; // String representation - } arch_t; - - #ifndef EM_486 - #define EM_486 6 /* Intel 80486 */ - #endif - - static const arch_t arch_array[]={ - {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, - {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, - {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, - {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, - {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, - {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, - {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, - {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, - {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, - {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, - {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, - {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, - {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, - {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, - {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, - {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"} - }; - - #if (defined IA32) - static Elf32_Half running_arch_code=EM_386; - #elif (defined AMD64) - static Elf32_Half running_arch_code=EM_X86_64; - #elif (defined IA64) - static Elf32_Half running_arch_code=EM_IA_64; - #elif (defined __sparc) && (defined _LP64) - static Elf32_Half running_arch_code=EM_SPARCV9; - #elif (defined __sparc) && (!defined _LP64) - static Elf32_Half running_arch_code=EM_SPARC; - #elif (defined __powerpc64__) - static Elf32_Half running_arch_code=EM_PPC64; - #elif (defined __powerpc__) - static Elf32_Half running_arch_code=EM_PPC; - #elif (defined ARM) - static Elf32_Half running_arch_code=EM_ARM; - #elif (defined S390) - static Elf32_Half running_arch_code=EM_S390; - #elif (defined ALPHA) - static Elf32_Half running_arch_code=EM_ALPHA; - #elif (defined MIPSEL) - static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; - #elif (defined PARISC) - static Elf32_Half running_arch_code=EM_PARISC; - #elif (defined MIPS) - static Elf32_Half running_arch_code=EM_MIPS; - #elif (defined M68K) - static Elf32_Half running_arch_code=EM_68K; - #else - #error Method os::dll_load requires that one of following is defined:\ - IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K - #endif - - // Identify compatability class for VM's architecture and library's architecture - // Obtain string descriptions for architectures - - arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; - int running_arch_index=-1; - - for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) { - if (running_arch_code == arch_array[i].code) { - running_arch_index = i; - } - if (lib_arch.code == arch_array[i].code) { - lib_arch.compat_class = arch_array[i].compat_class; - lib_arch.name = arch_array[i].name; - } - } - - assert(running_arch_index != -1, - "Didn't find running architecture code (running_arch_code) in arch_array"); - if (running_arch_index == -1) { - // Even though running architecture detection failed - // we may still continue with reporting dlerror() message - return NULL; - } - - if (lib_arch.endianess != arch_array[running_arch_index].endianess) { - ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); - return NULL; - } - -#ifndef S390 - if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { - ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); - return NULL; - } -#endif // !S390 - - if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { - if ( lib_arch.name!=NULL ) { - ::snprintf(diag_msg_buf, diag_msg_max_length-1, - " (Possible cause: can't load %s-bit .so on a %s-bit platform)", - lib_arch.name, arch_array[running_arch_index].name); - } else { - ::snprintf(diag_msg_buf, diag_msg_max_length-1, - " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", - lib_arch.code, - arch_array[running_arch_index].name); - } - } - - return NULL; -} - -/* - * glibc-2.0 libdl is not MT safe. If you are building with any glibc, - * chances are you might want to run the generated bits against glibc-2.0 - * libdl.so, so always use locking for any version of glibc. - */ -void* os::dll_lookup(void* handle, const char* name) { - pthread_mutex_lock(&dl_mutex); - void* res = dlsym(handle, name); - pthread_mutex_unlock(&dl_mutex); - return res; -} - - -static bool _print_ascii_file(const char* filename, outputStream* st) { - int fd = ::open(filename, O_RDONLY); - if (fd == -1) { - return false; - } - - char buf[32]; - int bytes; - while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) { - st->print_raw(buf, bytes); - } - - ::close(fd); - - return true; -} - -void os::print_dll_info(outputStream *st) { - st->print_cr("Dynamic libraries:"); - - char fname[32]; - pid_t pid = os::Linux::gettid(); - - jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid); - - if (!_print_ascii_file(fname, st)) { - st->print("Can not get library information for pid = %d\n", pid); - } -} - - -void os::print_os_info(outputStream* st) { - st->print("OS:"); - - // Try to identify popular distros. - // Most Linux distributions have /etc/XXX-release file, which contains - // the OS version string. Some have more than one /etc/XXX-release file - // (e.g. Mandrake has both /etc/mandrake-release and /etc/redhat-release.), - // so the order is important. - if (!_print_ascii_file("/etc/mandrake-release", st) && - !_print_ascii_file("/etc/sun-release", st) && - !_print_ascii_file("/etc/redhat-release", st) && - !_print_ascii_file("/etc/SuSE-release", st) && - !_print_ascii_file("/etc/turbolinux-release", st) && - !_print_ascii_file("/etc/gentoo-release", st) && - !_print_ascii_file("/etc/debian_version", st) && - !_print_ascii_file("/etc/ltib-release", st) && - !_print_ascii_file("/etc/angstrom-version", st)) { - st->print("Linux"); - } - st->cr(); - - // kernel - st->print("uname:"); - struct utsname name; - uname(&name); - st->print(name.sysname); st->print(" "); - st->print(name.release); st->print(" "); - st->print(name.version); st->print(" "); - st->print(name.machine); - st->cr(); - - // Print warning if unsafe chroot environment detected - if (unsafe_chroot_detected) { - st->print("WARNING!! "); - st->print_cr(unstable_chroot_error); - } - - // libc, pthread - st->print("libc:"); - st->print(os::Linux::glibc_version()); st->print(" "); - st->print(os::Linux::libpthread_version()); st->print(" "); - if (os::Linux::is_LinuxThreads()) { - st->print("(%s stack)", os::Linux::is_floating_stack() ? "floating" : "fixed"); - } - st->cr(); - - // rlimit - st->print("rlimit:"); - struct rlimit rlim; - - st->print(" STACK "); - getrlimit(RLIMIT_STACK, &rlim); - if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); - else st->print("%uk", rlim.rlim_cur >> 10); - - st->print(", CORE "); - getrlimit(RLIMIT_CORE, &rlim); - if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); - else st->print("%uk", rlim.rlim_cur >> 10); - - st->print(", NPROC "); - getrlimit(RLIMIT_NPROC, &rlim); - if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); - else st->print("%d", rlim.rlim_cur); - - st->print(", NOFILE "); - getrlimit(RLIMIT_NOFILE, &rlim); - if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); - else st->print("%d", rlim.rlim_cur); - - st->print(", AS "); - getrlimit(RLIMIT_AS, &rlim); - if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); - else st->print("%uk", rlim.rlim_cur >> 10); - st->cr(); - - // load average - st->print("load average:"); - double loadavg[3]; - os::loadavg(loadavg, 3); - st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]); - st->cr(); - - // meminfo - st->print("\n/proc/meminfo:\n"); - _print_ascii_file("/proc/meminfo", st); - st->cr(); -} - -void os::pd_print_cpu_info(outputStream* st) { - st->print("\n/proc/cpuinfo:\n"); - if (!_print_ascii_file("/proc/cpuinfo", st)) { - st->print(" "); - } - st->cr(); -} - -void os::print_memory_info(outputStream* st) { - - st->print("Memory:"); - st->print(" %dk page", os::vm_page_size()>>10); - - // values in struct sysinfo are "unsigned long" - struct sysinfo si; - sysinfo(&si); - - st->print(", physical " UINT64_FORMAT "k", - os::physical_memory() >> 10); - st->print("(" UINT64_FORMAT "k free)", - os::available_memory() >> 10); - st->print(", swap " UINT64_FORMAT "k", - ((jlong)si.totalswap * si.mem_unit) >> 10); - st->print("(" UINT64_FORMAT "k free)", - ((jlong)si.freeswap * si.mem_unit) >> 10); - st->cr(); -} - -// Taken from /usr/include/bits/siginfo.h Supposed to be architecture specific -// but they're the same for all the linux arch that we support -// and they're the same for solaris but there's no common place to put this. -const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR", - "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG", - "ILL_COPROC", "ILL_BADSTK" }; - -const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV", - "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES", - "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" }; - -const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" }; - -const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" }; - -void os::print_siginfo(outputStream* st, void* siginfo) { - st->print("siginfo:"); - - const int buflen = 100; - char buf[buflen]; - siginfo_t *si = (siginfo_t*)siginfo; - st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen)); - if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) { - st->print("si_errno=%s", buf); - } else { - st->print("si_errno=%d", si->si_errno); - } - const int c = si->si_code; - assert(c > 0, "unexpected si_code"); - switch (si->si_signo) { - case SIGILL: - st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]); - st->print(", si_addr=" PTR_FORMAT, si->si_addr); - break; - case SIGFPE: - st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]); - st->print(", si_addr=" PTR_FORMAT, si->si_addr); - break; - case SIGSEGV: - st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]); - st->print(", si_addr=" PTR_FORMAT, si->si_addr); - break; - case SIGBUS: - st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]); - st->print(", si_addr=" PTR_FORMAT, si->si_addr); - break; - default: - st->print(", si_code=%d", si->si_code); - // no si_addr - } - - if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && - UseSharedSpaces) { - FileMapInfo* mapinfo = FileMapInfo::current_info(); - if (mapinfo->is_in_shared_space(si->si_addr)) { - st->print("\n\nError accessing class data sharing archive." \ - " Mapped file inaccessible during execution, " \ - " possible disk/network problem."); - } - } - st->cr(); -} - - -static void print_signal_handler(outputStream* st, int sig, - char* buf, size_t buflen); - -void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { - st->print_cr("Signal Handlers:"); - print_signal_handler(st, SIGSEGV, buf, buflen); - print_signal_handler(st, SIGBUS , buf, buflen); - print_signal_handler(st, SIGFPE , buf, buflen); - print_signal_handler(st, SIGPIPE, buf, buflen); - print_signal_handler(st, SIGXFSZ, buf, buflen); - print_signal_handler(st, SIGILL , buf, buflen); - print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); - print_signal_handler(st, SR_signum, buf, buflen); - print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); - print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); - print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); - print_signal_handler(st, BREAK_SIGNAL, buf, buflen); -} - -static char saved_jvm_path[MAXPATHLEN] = {0}; - -// Find the full path to the current module, libjvm.so or libjvm_g.so -void os::jvm_path(char *buf, jint buflen) { - // Error checking. - if (buflen < MAXPATHLEN) { - assert(false, "must use a large-enough buffer"); - buf[0] = '\0'; - return; - } - // Lazy resolve the path to current module. - if (saved_jvm_path[0] != 0) { - strcpy(buf, saved_jvm_path); - return; - } - - char dli_fname[MAXPATHLEN]; - bool ret = dll_address_to_library_name( - CAST_FROM_FN_PTR(address, os::jvm_path), - dli_fname, sizeof(dli_fname), NULL); - assert(ret != 0, "cannot locate libjvm"); - char *rp = realpath(dli_fname, buf); - if (rp == NULL) - return; - - if (Arguments::created_by_gamma_launcher()) { - // Support for the gamma launcher. Typical value for buf is - // "/jre/lib///libjvm.so". If "/jre/lib/" appears at - // the right place in the string, then assume we are installed in a JDK and - // we're done. Otherwise, check for a JAVA_HOME environment variable and fix - // up the path so it looks like libjvm.so is installed there (append a - // fake suffix hotspot/libjvm.so). - const char *p = buf + strlen(buf) - 1; - for (int count = 0; p > buf && count < 5; ++count) { - for (--p; p > buf && *p != '/'; --p) - /* empty */ ; - } - - if (strncmp(p, "/jre/lib/", 9) != 0) { - // Look for JAVA_HOME in the environment. - char* java_home_var = ::getenv("JAVA_HOME"); - if (java_home_var != NULL && java_home_var[0] != 0) { - char* jrelib_p; - int len; - - // Check the current module name "libjvm.so" or "libjvm_g.so". - p = strrchr(buf, '/'); - assert(strstr(p, "/libjvm") == p, "invalid library name"); - p = strstr(p, "_g") ? "_g" : ""; - - rp = realpath(java_home_var, buf); - if (rp == NULL) - return; - - // determine if this is a legacy image or modules image - // modules image doesn't have "jre" subdirectory - len = strlen(buf); - jrelib_p = buf + len; - snprintf(jrelib_p, buflen-len, "/jre/lib/%s", cpu_arch); - if (0 != access(buf, F_OK)) { - snprintf(jrelib_p, buflen-len, "/lib/%s", cpu_arch); - } - - if (0 == access(buf, F_OK)) { - // Use current module name "libjvm[_g].so" instead of - // "libjvm"debug_only("_g")".so" since for fastdebug version - // we should have "libjvm.so" but debug_only("_g") adds "_g"! - len = strlen(buf); - snprintf(buf + len, buflen-len, "/hotspot/libjvm%s.so", p); - } else { - // Go back to path of .so - rp = realpath(dli_fname, buf); - if (rp == NULL) - return; - } - } - } - } - - strcpy(saved_jvm_path, buf); -} - -void os::print_jni_name_prefix_on(outputStream* st, int args_size) { - // no prefix required, not even "_" -} - -void os::print_jni_name_suffix_on(outputStream* st, int args_size) { - // no suffix required -} - -//////////////////////////////////////////////////////////////////////////////// -// sun.misc.Signal support - -static volatile jint sigint_count = 0; - -static void -UserHandler(int sig, void *siginfo, void *context) { - // 4511530 - sem_post is serialized and handled by the manager thread. When - // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We - // don't want to flood the manager thread with sem_post requests. - if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) - return; - - // Ctrl-C is pressed during error reporting, likely because the error - // handler fails to abort. Let VM die immediately. - if (sig == SIGINT && is_error_reported()) { - os::die(); - } - - os::signal_notify(sig); -} - -void* os::user_handler() { - return CAST_FROM_FN_PTR(void*, UserHandler); -} - -extern "C" { - typedef void (*sa_handler_t)(int); - typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); -} - -void* os::signal(int signal_number, void* handler) { - struct sigaction sigAct, oldSigAct; - - sigfillset(&(sigAct.sa_mask)); - sigAct.sa_flags = SA_RESTART|SA_SIGINFO; - sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); - - if (sigaction(signal_number, &sigAct, &oldSigAct)) { - // -1 means registration failed - return (void *)-1; - } - - return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); -} - -void os::signal_raise(int signal_number) { - ::raise(signal_number); -} - -/* - * The following code is moved from os.cpp for making this - * code platform specific, which it is by its very nature. - */ - -// Will be modified when max signal is changed to be dynamic -int os::sigexitnum_pd() { - return NSIG; -} - -// a counter for each possible signal value -static volatile jint pending_signals[NSIG+1] = { 0 }; - -// Linux(POSIX) specific hand shaking semaphore. -static sem_t sig_sem; - -void os::signal_init_pd() { - // Initialize signal structures - ::memset((void*)pending_signals, 0, sizeof(pending_signals)); - - // Initialize signal semaphore - ::sem_init(&sig_sem, 0, 0); -} - -void os::signal_notify(int sig) { - Atomic::inc(&pending_signals[sig]); - ::sem_post(&sig_sem); -} - -static int check_pending_signals(bool wait) { - Atomic::store(0, &sigint_count); - for (;;) { - for (int i = 0; i < NSIG + 1; i++) { - jint n = pending_signals[i]; - if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { - return i; - } - } - if (!wait) { - return -1; - } - JavaThread *thread = JavaThread::current(); - ThreadBlockInVM tbivm(thread); - - bool threadIsSuspended; - do { - thread->set_suspend_equivalent(); - // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() - ::sem_wait(&sig_sem); - - // were we externally suspended while we were waiting? - threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); - if (threadIsSuspended) { - // - // The semaphore has been incremented, but while we were waiting - // another thread suspended us. We don't want to continue running - // while suspended because that would surprise the thread that - // suspended us. - // - ::sem_post(&sig_sem); - - thread->java_suspend_self(); - } - } while (threadIsSuspended); - } -} - -int os::signal_lookup() { - return check_pending_signals(false); -} - -int os::signal_wait() { - return check_pending_signals(true); -} - -//////////////////////////////////////////////////////////////////////////////// -// Virtual Memory - -int os::vm_page_size() { - // Seems redundant as all get out - assert(os::Linux::page_size() != -1, "must call os::init"); - return os::Linux::page_size(); -} - -// Solaris allocates memory by pages. -int os::vm_allocation_granularity() { - assert(os::Linux::page_size() != -1, "must call os::init"); - return os::Linux::page_size(); -} - -// Rationale behind this function: -// current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable -// mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get -// samples for JITted code. Here we create private executable mapping over the code cache -// and then we can use standard (well, almost, as mapping can change) way to provide -// info for the reporting script by storing timestamp and location of symbol -void linux_wrap_code(char* base, size_t size) { - static volatile jint cnt = 0; - - if (!UseOprofile) { - return; - } - - char buf[PATH_MAX+1]; - int num = Atomic::add(1, &cnt); - - snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d", - os::get_temp_directory(), os::current_process_id(), num); - unlink(buf); - - int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); - - if (fd != -1) { - off_t rv = ::lseek(fd, size-2, SEEK_SET); - if (rv != (off_t)-1) { - if (::write(fd, "", 1) == 1) { - mmap(base, size, - PROT_READ|PROT_WRITE|PROT_EXEC, - MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); - } - } - ::close(fd); - unlink(buf); - } -} - -// NOTE: Linux kernel does not really reserve the pages for us. -// All it does is to check if there are enough free pages -// left at the time of mmap(). This could be a potential -// problem. -bool os::commit_memory(char* addr, size_t size, bool exec) { - int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; - uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, - MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); - if (res != (uintptr_t) MAP_FAILED) { - if (UseNUMAInterleaving) { - numa_make_global(addr, size); - } - return true; - } - return false; -} - -// Define MAP_HUGETLB here so we can build HotSpot on old systems. -#ifndef MAP_HUGETLB -#define MAP_HUGETLB 0x40000 -#endif - -// Define MADV_HUGEPAGE here so we can build HotSpot on old systems. -#ifndef MADV_HUGEPAGE -#define MADV_HUGEPAGE 14 -#endif - -bool os::commit_memory(char* addr, size_t size, size_t alignment_hint, - bool exec) { - if (UseHugeTLBFS && alignment_hint > (size_t)vm_page_size()) { - int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; - uintptr_t res = - (uintptr_t) ::mmap(addr, size, prot, - MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS|MAP_HUGETLB, - -1, 0); - if (res != (uintptr_t) MAP_FAILED) { - if (UseNUMAInterleaving) { - numa_make_global(addr, size); - } - return true; - } - // Fall through and try to use small pages - } - - if (commit_memory(addr, size, exec)) { - realign_memory(addr, size, alignment_hint); - return true; - } - return false; -} - -void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) { - if (UseHugeTLBFS && alignment_hint > (size_t)vm_page_size()) { - // We don't check the return value: madvise(MADV_HUGEPAGE) may not - // be supported or the memory may already be backed by huge pages. - ::madvise(addr, bytes, MADV_HUGEPAGE); - } -} - -void os::free_memory(char *addr, size_t bytes) { - commit_memory(addr, bytes, false); -} - -void os::numa_make_global(char *addr, size_t bytes) { - Linux::numa_interleave_memory(addr, bytes); -} - -void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { - Linux::numa_tonode_memory(addr, bytes, lgrp_hint); -} - -bool os::numa_topology_changed() { return false; } - -size_t os::numa_get_groups_num() { - int max_node = Linux::numa_max_node(); - return max_node > 0 ? max_node + 1 : 1; -} - -int os::numa_get_group_id() { - int cpu_id = Linux::sched_getcpu(); - if (cpu_id != -1) { - int lgrp_id = Linux::get_node_by_cpu(cpu_id); - if (lgrp_id != -1) { - return lgrp_id; - } - } - return 0; -} - -size_t os::numa_get_leaf_groups(int *ids, size_t size) { - for (size_t i = 0; i < size; i++) { - ids[i] = i; - } - return size; -} - -bool os::get_page_info(char *start, page_info* info) { - return false; -} - -char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { - return end; -} - - -int os::Linux::sched_getcpu_syscall(void) { - unsigned int cpu; - int retval = -1; - -#if defined(IA32) -# ifndef SYS_getcpu -# define SYS_getcpu 318 -# endif - retval = syscall(SYS_getcpu, &cpu, NULL, NULL); -#elif defined(AMD64) -// Unfortunately we have to bring all these macros here from vsyscall.h -// to be able to compile on old linuxes. -# define __NR_vgetcpu 2 -# define VSYSCALL_START (-10UL << 20) -# define VSYSCALL_SIZE 1024 -# define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr)) - typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache); - vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu); - retval = vgetcpu(&cpu, NULL, NULL); -#endif - - return (retval == -1) ? retval : cpu; -} - -// Something to do with the numa-aware allocator needs these symbols -extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { } -extern "C" JNIEXPORT void numa_error(char *where) { } -extern "C" JNIEXPORT int fork1() { return fork(); } - - -// If we are running with libnuma version > 2, then we should -// be trying to use symbols with versions 1.1 -// If we are running with earlier version, which did not have symbol versions, -// we should use the base version. -void* os::Linux::libnuma_dlsym(void* handle, const char *name) { - void *f = dlvsym(handle, name, "libnuma_1.1"); - if (f == NULL) { - f = dlsym(handle, name); - } - return f; -} - -bool os::Linux::libnuma_init() { - // sched_getcpu() should be in libc. - set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, - dlsym(RTLD_DEFAULT, "sched_getcpu"))); - - // If it's not, try a direct syscall. - if (sched_getcpu() == -1) - set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, (void*)&sched_getcpu_syscall)); - - if (sched_getcpu() != -1) { // Does it work? - void *handle = dlopen("libnuma.so.1", RTLD_LAZY); - if (handle != NULL) { - set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t, - libnuma_dlsym(handle, "numa_node_to_cpus"))); - set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t, - libnuma_dlsym(handle, "numa_max_node"))); - set_numa_available(CAST_TO_FN_PTR(numa_available_func_t, - libnuma_dlsym(handle, "numa_available"))); - set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t, - libnuma_dlsym(handle, "numa_tonode_memory"))); - set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t, - libnuma_dlsym(handle, "numa_interleave_memory"))); - - - if (numa_available() != -1) { - set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes")); - // Create a cpu -> node mapping - _cpu_to_node = new (ResourceObj::C_HEAP) GrowableArray(0, true); - rebuild_cpu_to_node_map(); - return true; - } - } - } - return false; -} - -// rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id. -// The table is later used in get_node_by_cpu(). -void os::Linux::rebuild_cpu_to_node_map() { - const size_t NCPUS = 32768; // Since the buffer size computation is very obscure - // in libnuma (possible values are starting from 16, - // and continuing up with every other power of 2, but less - // than the maximum number of CPUs supported by kernel), and - // is a subject to change (in libnuma version 2 the requirements - // are more reasonable) we'll just hardcode the number they use - // in the library. - const size_t BitsPerCLong = sizeof(long) * CHAR_BIT; - - size_t cpu_num = os::active_processor_count(); - size_t cpu_map_size = NCPUS / BitsPerCLong; - size_t cpu_map_valid_size = - MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size); - - cpu_to_node()->clear(); - cpu_to_node()->at_grow(cpu_num - 1); - size_t node_num = numa_get_groups_num(); - - unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size); - for (size_t i = 0; i < node_num; i++) { - if (numa_node_to_cpus(i, cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) { - for (size_t j = 0; j < cpu_map_valid_size; j++) { - if (cpu_map[j] != 0) { - for (size_t k = 0; k < BitsPerCLong; k++) { - if (cpu_map[j] & (1UL << k)) { - cpu_to_node()->at_put(j * BitsPerCLong + k, i); - } - } - } - } - } - } - FREE_C_HEAP_ARRAY(unsigned long, cpu_map); -} - -int os::Linux::get_node_by_cpu(int cpu_id) { - if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) { - return cpu_to_node()->at(cpu_id); - } - return -1; -} - -GrowableArray* os::Linux::_cpu_to_node; -os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu; -os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus; -os::Linux::numa_max_node_func_t os::Linux::_numa_max_node; -os::Linux::numa_available_func_t os::Linux::_numa_available; -os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory; -os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory; -unsigned long* os::Linux::_numa_all_nodes; - -bool os::uncommit_memory(char* addr, size_t size) { - uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, - MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); - return res != (uintptr_t) MAP_FAILED; -} - -// Linux uses a growable mapping for the stack, and if the mapping for -// the stack guard pages is not removed when we detach a thread the -// stack cannot grow beyond the pages where the stack guard was -// mapped. If at some point later in the process the stack expands to -// that point, the Linux kernel cannot expand the stack any further -// because the guard pages are in the way, and a segfault occurs. -// -// However, it's essential not to split the stack region by unmapping -// a region (leaving a hole) that's already part of the stack mapping, -// so if the stack mapping has already grown beyond the guard pages at -// the time we create them, we have to truncate the stack mapping. -// So, we need to know the extent of the stack mapping when -// create_stack_guard_pages() is called. - -// Find the bounds of the stack mapping. Return true for success. -// -// We only need this for stacks that are growable: at the time of -// writing thread stacks don't use growable mappings (i.e. those -// creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this -// only applies to the main thread. - -static -bool get_stack_bounds(uintptr_t *bottom, uintptr_t *top) { - - char buf[128]; - int fd, sz; - - if ((fd = ::open("/proc/self/maps", O_RDONLY)) < 0) { - return false; - } - - const char kw[] = "[stack]"; - const int kwlen = sizeof(kw)-1; - - // Address part of /proc/self/maps couldn't be more than 128 bytes - while ((sz = os::get_line_chars(fd, buf, sizeof(buf))) > 0) { - if (sz > kwlen && ::memcmp(buf+sz-kwlen, kw, kwlen) == 0) { - // Extract addresses - if (sscanf(buf, "%" SCNxPTR "-%" SCNxPTR, bottom, top) == 2) { - uintptr_t sp = (uintptr_t) __builtin_frame_address(0); - if (sp >= *bottom && sp <= *top) { - ::close(fd); - return true; - } - } - } - } - - ::close(fd); - return false; -} - - -// If the (growable) stack mapping already extends beyond the point -// where we're going to put our guard pages, truncate the mapping at -// that point by munmap()ping it. This ensures that when we later -// munmap() the guard pages we don't leave a hole in the stack -// mapping. This only affects the main/initial thread, but guard -// against future OS changes -bool os::create_stack_guard_pages(char* addr, size_t size) { - uintptr_t stack_extent, stack_base; - bool chk_bounds = NOT_DEBUG(os::Linux::is_initial_thread()) DEBUG_ONLY(true); - if (chk_bounds && get_stack_bounds(&stack_extent, &stack_base)) { - assert(os::Linux::is_initial_thread(), - "growable stack in non-initial thread"); - if (stack_extent < (uintptr_t)addr) - ::munmap((void*)stack_extent, (uintptr_t)addr - stack_extent); - } - - return os::commit_memory(addr, size); -} - -// If this is a growable mapping, remove the guard pages entirely by -// munmap()ping them. If not, just call uncommit_memory(). This only -// affects the main/initial thread, but guard against future OS changes -bool os::remove_stack_guard_pages(char* addr, size_t size) { - uintptr_t stack_extent, stack_base; - bool chk_bounds = NOT_DEBUG(os::Linux::is_initial_thread()) DEBUG_ONLY(true); - if (chk_bounds && get_stack_bounds(&stack_extent, &stack_base)) { - assert(os::Linux::is_initial_thread(), - "growable stack in non-initial thread"); - - return ::munmap(addr, size) == 0; - } - - return os::uncommit_memory(addr, size); -} - -static address _highest_vm_reserved_address = NULL; - -// If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory -// at 'requested_addr'. If there are existing memory mappings at the same -// location, however, they will be overwritten. If 'fixed' is false, -// 'requested_addr' is only treated as a hint, the return value may or -// may not start from the requested address. Unlike Linux mmap(), this -// function returns NULL to indicate failure. -static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { - char * addr; - int flags; - - flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; - if (fixed) { - assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address"); - flags |= MAP_FIXED; - } - - // Map uncommitted pages PROT_READ and PROT_WRITE, change access - // to PROT_EXEC if executable when we commit the page. - addr = (char*)::mmap(requested_addr, bytes, PROT_READ|PROT_WRITE, - flags, -1, 0); - - if (addr != MAP_FAILED) { - // anon_mmap() should only get called during VM initialization, - // don't need lock (actually we can skip locking even it can be called - // from multiple threads, because _highest_vm_reserved_address is just a - // hint about the upper limit of non-stack memory regions.) - if ((address)addr + bytes > _highest_vm_reserved_address) { - _highest_vm_reserved_address = (address)addr + bytes; - } - } - - return addr == MAP_FAILED ? NULL : addr; -} - -// Don't update _highest_vm_reserved_address, because there might be memory -// regions above addr + size. If so, releasing a memory region only creates -// a hole in the address space, it doesn't help prevent heap-stack collision. -// -static int anon_munmap(char * addr, size_t size) { - return ::munmap(addr, size) == 0; -} - -char* os::reserve_memory(size_t bytes, char* requested_addr, - size_t alignment_hint) { - return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); -} - -bool os::release_memory(char* addr, size_t size) { - return anon_munmap(addr, size); -} - -static address highest_vm_reserved_address() { - return _highest_vm_reserved_address; -} - -static bool linux_mprotect(char* addr, size_t size, int prot) { - // Linux wants the mprotect address argument to be page aligned. - char* bottom = (char*)align_size_down((intptr_t)addr, os::Linux::page_size()); - - // According to SUSv3, mprotect() should only be used with mappings - // established by mmap(), and mmap() always maps whole pages. Unaligned - // 'addr' likely indicates problem in the VM (e.g. trying to change - // protection of malloc'ed or statically allocated memory). Check the - // caller if you hit this assert. - assert(addr == bottom, "sanity check"); - - size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size()); - return ::mprotect(bottom, size, prot) == 0; -} - -// Set protections specified -bool os::protect_memory(char* addr, size_t bytes, ProtType prot, - bool is_committed) { - unsigned int p = 0; - switch (prot) { - case MEM_PROT_NONE: p = PROT_NONE; break; - case MEM_PROT_READ: p = PROT_READ; break; - case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; - case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; - default: - ShouldNotReachHere(); - } - // is_committed is unused. - return linux_mprotect(addr, bytes, p); -} - -bool os::guard_memory(char* addr, size_t size) { - return linux_mprotect(addr, size, PROT_NONE); -} - -bool os::unguard_memory(char* addr, size_t size) { - return linux_mprotect(addr, size, PROT_READ|PROT_WRITE); -} - -bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) { - bool result = false; - void *p = mmap (NULL, page_size, PROT_READ|PROT_WRITE, - MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB, - -1, 0); - - if (p != (void *) -1) { - // We don't know if this really is a huge page or not. - FILE *fp = fopen("/proc/self/maps", "r"); - if (fp) { - while (!feof(fp)) { - char chars[257]; - long x = 0; - if (fgets(chars, sizeof(chars), fp)) { - if (sscanf(chars, "%lx-%*x", &x) == 1 - && x == (long)p) { - if (strstr (chars, "hugepage")) { - result = true; - break; - } - } - } - } - fclose(fp); - } - munmap (p, page_size); - if (result) - return true; - } - - if (warn) { - warning("HugeTLBFS is not supported by the operating system."); - } - - return result; -} - -/* -* Set the coredump_filter bits to include largepages in core dump (bit 6) -* -* From the coredump_filter documentation: -* -* - (bit 0) anonymous private memory -* - (bit 1) anonymous shared memory -* - (bit 2) file-backed private memory -* - (bit 3) file-backed shared memory -* - (bit 4) ELF header pages in file-backed private memory areas (it is -* effective only if the bit 2 is cleared) -* - (bit 5) hugetlb private memory -* - (bit 6) hugetlb shared memory -*/ -static void set_coredump_filter(void) { - FILE *f; - long cdm; - - if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) { - return; - } - - if (fscanf(f, "%lx", &cdm) != 1) { - fclose(f); - return; - } - - rewind(f); - - if ((cdm & LARGEPAGES_BIT) == 0) { - cdm |= LARGEPAGES_BIT; - fprintf(f, "%#lx", cdm); - } - - fclose(f); -} - -// Large page support - -static size_t _large_page_size = 0; - -void os::large_page_init() { - if (!UseLargePages) { - UseHugeTLBFS = false; - UseSHM = false; - return; - } - - if (FLAG_IS_DEFAULT(UseHugeTLBFS) && FLAG_IS_DEFAULT(UseSHM)) { - // If UseLargePages is specified on the command line try both methods, - // if it's default, then try only HugeTLBFS. - if (FLAG_IS_DEFAULT(UseLargePages)) { - UseHugeTLBFS = true; - } else { - UseHugeTLBFS = UseSHM = true; - } - } - - if (LargePageSizeInBytes) { - _large_page_size = LargePageSizeInBytes; - } else { - // large_page_size on Linux is used to round up heap size. x86 uses either - // 2M or 4M page, depending on whether PAE (Physical Address Extensions) - // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use - // page as large as 256M. - // - // Here we try to figure out page size by parsing /proc/meminfo and looking - // for a line with the following format: - // Hugepagesize: 2048 kB - // - // If we can't determine the value (e.g. /proc is not mounted, or the text - // format has been changed), we'll use the largest page size supported by - // the processor. - -#ifndef ZERO - _large_page_size = IA32_ONLY(4 * M) AMD64_ONLY(2 * M) IA64_ONLY(256 * M) SPARC_ONLY(4 * M) - ARM_ONLY(2 * M) PPC_ONLY(4 * M); -#endif // ZERO - - FILE *fp = fopen("/proc/meminfo", "r"); - if (fp) { - while (!feof(fp)) { - int x = 0; - char buf[16]; - if (fscanf(fp, "Hugepagesize: %d", &x) == 1) { - if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) { - _large_page_size = x * K; - break; - } - } else { - // skip to next line - for (;;) { - int ch = fgetc(fp); - if (ch == EOF || ch == (int)'\n') break; - } - } - } - fclose(fp); - } - } - - // print a warning if any large page related flag is specified on command line - bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS); - - const size_t default_page_size = (size_t)Linux::page_size(); - if (_large_page_size > default_page_size) { - _page_sizes[0] = _large_page_size; - _page_sizes[1] = default_page_size; - _page_sizes[2] = 0; - } - UseHugeTLBFS = UseHugeTLBFS && - Linux::hugetlbfs_sanity_check(warn_on_failure, _large_page_size); - - if (UseHugeTLBFS) - UseSHM = false; - - UseLargePages = UseHugeTLBFS || UseSHM; - - set_coredump_filter(); -} - -#ifndef SHM_HUGETLB -#define SHM_HUGETLB 04000 -#endif - -char* os::reserve_memory_special(size_t bytes, char* req_addr, bool exec) { - // "exec" is passed in but not used. Creating the shared image for - // the code cache doesn't have an SHM_X executable permission to check. - assert(UseLargePages && UseSHM, "only for SHM large pages"); - - key_t key = IPC_PRIVATE; - char *addr; - - bool warn_on_failure = UseLargePages && - (!FLAG_IS_DEFAULT(UseLargePages) || - !FLAG_IS_DEFAULT(LargePageSizeInBytes) - ); - char msg[128]; - - // Create a large shared memory region to attach to based on size. - // Currently, size is the total size of the heap - int shmid = shmget(key, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W); - if (shmid == -1) { - // Possible reasons for shmget failure: - // 1. shmmax is too small for Java heap. - // > check shmmax value: cat /proc/sys/kernel/shmmax - // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax - // 2. not enough large page memory. - // > check available large pages: cat /proc/meminfo - // > increase amount of large pages: - // echo new_value > /proc/sys/vm/nr_hugepages - // Note 1: different Linux may use different name for this property, - // e.g. on Redhat AS-3 it is "hugetlb_pool". - // Note 2: it's possible there's enough physical memory available but - // they are so fragmented after a long run that they can't - // coalesce into large pages. Try to reserve large pages when - // the system is still "fresh". - if (warn_on_failure) { - jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno); - warning(msg); - } - return NULL; - } - - // attach to the region - addr = (char*)shmat(shmid, req_addr, 0); - int err = errno; - - // Remove shmid. If shmat() is successful, the actual shared memory segment - // will be deleted when it's detached by shmdt() or when the process - // terminates. If shmat() is not successful this will remove the shared - // segment immediately. - shmctl(shmid, IPC_RMID, NULL); - - if ((intptr_t)addr == -1) { - if (warn_on_failure) { - jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err); - warning(msg); - } - return NULL; - } - - if ((addr != NULL) && UseNUMAInterleaving) { - numa_make_global(addr, bytes); - } - - return addr; -} - -bool os::release_memory_special(char* base, size_t bytes) { - // detaching the SHM segment will also delete it, see reserve_memory_special() - int rslt = shmdt(base); - return rslt == 0; -} - -size_t os::large_page_size() { - return _large_page_size; -} - -// HugeTLBFS allows application to commit large page memory on demand; -// with SysV SHM the entire memory region must be allocated as shared -// memory. -bool os::can_commit_large_page_memory() { - return UseHugeTLBFS; -} - -bool os::can_execute_large_page_memory() { - return UseHugeTLBFS; -} - -// Reserve memory at an arbitrary address, only if that area is -// available (and not reserved for something else). - -char* os::attempt_reserve_memory_at(size_t bytes, char* requested_addr) { - const int max_tries = 10; - char* base[max_tries]; - size_t size[max_tries]; - const size_t gap = 0x000000; - - // Assert only that the size is a multiple of the page size, since - // that's all that mmap requires, and since that's all we really know - // about at this low abstraction level. If we need higher alignment, - // we can either pass an alignment to this method or verify alignment - // in one of the methods further up the call chain. See bug 5044738. - assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); - - // Repeatedly allocate blocks until the block is allocated at the - // right spot. Give up after max_tries. Note that reserve_memory() will - // automatically update _highest_vm_reserved_address if the call is - // successful. The variable tracks the highest memory address every reserved - // by JVM. It is used to detect heap-stack collision if running with - // fixed-stack LinuxThreads. Because here we may attempt to reserve more - // space than needed, it could confuse the collision detecting code. To - // solve the problem, save current _highest_vm_reserved_address and - // calculate the correct value before return. - address old_highest = _highest_vm_reserved_address; - - // Linux mmap allows caller to pass an address as hint; give it a try first, - // if kernel honors the hint then we can return immediately. - char * addr = anon_mmap(requested_addr, bytes, false); - if (addr == requested_addr) { - return requested_addr; - } - - if (addr != NULL) { - // mmap() is successful but it fails to reserve at the requested address - anon_munmap(addr, bytes); - } - - int i; - for (i = 0; i < max_tries; ++i) { - base[i] = reserve_memory(bytes); - - if (base[i] != NULL) { - // Is this the block we wanted? - if (base[i] == requested_addr) { - size[i] = bytes; - break; - } - - // Does this overlap the block we wanted? Give back the overlapped - // parts and try again. - - size_t top_overlap = requested_addr + (bytes + gap) - base[i]; - if (top_overlap >= 0 && top_overlap < bytes) { - unmap_memory(base[i], top_overlap); - base[i] += top_overlap; - size[i] = bytes - top_overlap; - } else { - size_t bottom_overlap = base[i] + bytes - requested_addr; - if (bottom_overlap >= 0 && bottom_overlap < bytes) { - unmap_memory(requested_addr, bottom_overlap); - size[i] = bytes - bottom_overlap; - } else { - size[i] = bytes; - } - } - } - } - - // Give back the unused reserved pieces. - - for (int j = 0; j < i; ++j) { - if (base[j] != NULL) { - unmap_memory(base[j], size[j]); - } - } - - if (i < max_tries) { - _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes); - return requested_addr; - } else { - _highest_vm_reserved_address = old_highest; - return NULL; - } -} - -size_t os::read(int fd, void *buf, unsigned int nBytes) { - return ::read(fd, buf, nBytes); -} - -// TODO-FIXME: reconcile Solaris' os::sleep with the linux variation. -// Solaris uses poll(), linux uses park(). -// Poll() is likely a better choice, assuming that Thread.interrupt() -// generates a SIGUSRx signal. Note that SIGUSR1 can interfere with -// SIGSEGV, see 4355769. - -const int NANOSECS_PER_MILLISECS = 1000000; - -int os::sleep(Thread* thread, jlong millis, bool interruptible) { - assert(thread == Thread::current(), "thread consistency check"); - - ParkEvent * const slp = thread->_SleepEvent ; - slp->reset() ; - OrderAccess::fence() ; - - if (interruptible) { - jlong prevtime = javaTimeNanos(); - - for (;;) { - if (os::is_interrupted(thread, true)) { - return OS_INTRPT; - } - - jlong newtime = javaTimeNanos(); - - if (newtime - prevtime < 0) { - // time moving backwards, should only happen if no monotonic clock - // not a guarantee() because JVM should not abort on kernel/glibc bugs - assert(!Linux::supports_monotonic_clock(), "time moving backwards"); - } else { - millis -= (newtime - prevtime) / NANOSECS_PER_MILLISECS; - } - - if(millis <= 0) { - return OS_OK; - } - - prevtime = newtime; - - { - assert(thread->is_Java_thread(), "sanity check"); - JavaThread *jt = (JavaThread *) thread; - ThreadBlockInVM tbivm(jt); - OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */); - - jt->set_suspend_equivalent(); - // cleared by handle_special_suspend_equivalent_condition() or - // java_suspend_self() via check_and_wait_while_suspended() - - slp->park(millis); - - // were we externally suspended while we were waiting? - jt->check_and_wait_while_suspended(); - } - } - } else { - OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); - jlong prevtime = javaTimeNanos(); - - for (;;) { - // It'd be nice to avoid the back-to-back javaTimeNanos() calls on - // the 1st iteration ... - jlong newtime = javaTimeNanos(); - - if (newtime - prevtime < 0) { - // time moving backwards, should only happen if no monotonic clock - // not a guarantee() because JVM should not abort on kernel/glibc bugs - assert(!Linux::supports_monotonic_clock(), "time moving backwards"); - } else { - millis -= (newtime - prevtime) / NANOSECS_PER_MILLISECS; - } - - if(millis <= 0) break ; - - prevtime = newtime; - slp->park(millis); - } - return OS_OK ; - } -} - -int os::naked_sleep() { - // %% make the sleep time an integer flag. for now use 1 millisec. - return os::sleep(Thread::current(), 1, false); -} - -// Sleep forever; naked call to OS-specific sleep; use with CAUTION -void os::infinite_sleep() { - while (true) { // sleep forever ... - ::sleep(100); // ... 100 seconds at a time - } -} - -// Used to convert frequent JVM_Yield() to nops -bool os::dont_yield() { - return DontYieldALot; -} - -void os::yield() { - sched_yield(); -} - -os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;} - -void os::yield_all(int attempts) { - // Yields to all threads, including threads with lower priorities - // Threads on Linux are all with same priority. The Solaris style - // os::yield_all() with nanosleep(1ms) is not necessary. - sched_yield(); -} - -// Called from the tight loops to possibly influence time-sharing heuristics -void os::loop_breaker(int attempts) { - os::yield_all(attempts); -} - -//////////////////////////////////////////////////////////////////////////////// -// thread priority support - -// Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER -// only supports dynamic priority, static priority must be zero. For real-time -// applications, Linux supports SCHED_RR which allows static priority (1-99). -// However, for large multi-threaded applications, SCHED_RR is not only slower -// than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out -// of 5 runs - Sep 2005). -// -// The following code actually changes the niceness of kernel-thread/LWP. It -// has an assumption that setpriority() only modifies one kernel-thread/LWP, -// not the entire user process, and user level threads are 1:1 mapped to kernel -// threads. It has always been the case, but could change in the future. For -// this reason, the code should not be used as default (ThreadPriorityPolicy=0). -// It is only used when ThreadPriorityPolicy=1 and requires root privilege. - -int os::java_to_os_priority[MaxPriority + 1] = { - 19, // 0 Entry should never be used - - 4, // 1 MinPriority - 3, // 2 - 2, // 3 - - 1, // 4 - 0, // 5 NormPriority - -1, // 6 - - -2, // 7 - -3, // 8 - -4, // 9 NearMaxPriority - - -5 // 10 MaxPriority -}; - -static int prio_init() { - if (ThreadPriorityPolicy == 1) { - // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 - // if effective uid is not root. Perhaps, a more elegant way of doing - // this is to test CAP_SYS_NICE capability, but that will require libcap.so - if (geteuid() != 0) { - if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { - warning("-XX:ThreadPriorityPolicy requires root privilege on Linux"); - } - ThreadPriorityPolicy = 0; - } - } - return 0; -} - -OSReturn os::set_native_priority(Thread* thread, int newpri) { - if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK; - - int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); - return (ret == 0) ? OS_OK : OS_ERR; -} - -OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { - if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) { - *priority_ptr = java_to_os_priority[NormPriority]; - return OS_OK; - } - - errno = 0; - *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); - return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); -} - -// Hint to the underlying OS that a task switch would not be good. -// Void return because it's a hint and can fail. -void os::hint_no_preempt() {} - -//////////////////////////////////////////////////////////////////////////////// -// suspend/resume support - -// the low-level signal-based suspend/resume support is a remnant from the -// old VM-suspension that used to be for java-suspension, safepoints etc, -// within hotspot. Now there is a single use-case for this: -// - calling get_thread_pc() on the VMThread by the flat-profiler task -// that runs in the watcher thread. -// The remaining code is greatly simplified from the more general suspension -// code that used to be used. -// -// The protocol is quite simple: -// - suspend: -// - sends a signal to the target thread -// - polls the suspend state of the osthread using a yield loop -// - target thread signal handler (SR_handler) sets suspend state -// and blocks in sigsuspend until continued -// - resume: -// - sets target osthread state to continue -// - sends signal to end the sigsuspend loop in the SR_handler -// -// Note that the SR_lock plays no role in this suspend/resume protocol. -// - -static void resume_clear_context(OSThread *osthread) { - osthread->set_ucontext(NULL); - osthread->set_siginfo(NULL); - - // notify the suspend action is completed, we have now resumed - osthread->sr.clear_suspended(); -} - -static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { - osthread->set_ucontext(context); - osthread->set_siginfo(siginfo); -} - -// -// Handler function invoked when a thread's execution is suspended or -// resumed. We have to be careful that only async-safe functions are -// called here (Note: most pthread functions are not async safe and -// should be avoided.) -// -// Note: sigwait() is a more natural fit than sigsuspend() from an -// interface point of view, but sigwait() prevents the signal hander -// from being run. libpthread would get very confused by not having -// its signal handlers run and prevents sigwait()'s use with the -// mutex granting granting signal. -// -// Currently only ever called on the VMThread -// -static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { - // Save and restore errno to avoid confusing native code with EINTR - // after sigsuspend. - int old_errno = errno; - - Thread* thread = Thread::current(); - OSThread* osthread = thread->osthread(); - assert(thread->is_VM_thread(), "Must be VMThread"); - // read current suspend action - int action = osthread->sr.suspend_action(); - if (action == SR_SUSPEND) { - suspend_save_context(osthread, siginfo, context); - - // Notify the suspend action is about to be completed. do_suspend() - // waits until SR_SUSPENDED is set and then returns. We will wait - // here for a resume signal and that completes the suspend-other - // action. do_suspend/do_resume is always called as a pair from - // the same thread - so there are no races - - // notify the caller - osthread->sr.set_suspended(); - - sigset_t suspend_set; // signals for sigsuspend() - - // get current set of blocked signals and unblock resume signal - pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); - sigdelset(&suspend_set, SR_signum); - - // wait here until we are resumed - do { - sigsuspend(&suspend_set); - // ignore all returns until we get a resume signal - } while (osthread->sr.suspend_action() != SR_CONTINUE); - - resume_clear_context(osthread); - - } else { - assert(action == SR_CONTINUE, "unexpected sr action"); - // nothing special to do - just leave the handler - } - - errno = old_errno; -} - - -static int SR_initialize() { - struct sigaction act; - char *s; - /* Get signal number to use for suspend/resume */ - if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { - int sig = ::strtol(s, 0, 10); - if (sig > 0 || sig < _NSIG) { - SR_signum = sig; - } - } - - assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, - "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); - - sigemptyset(&SR_sigset); - sigaddset(&SR_sigset, SR_signum); - - /* Set up signal handler for suspend/resume */ - act.sa_flags = SA_RESTART|SA_SIGINFO; - act.sa_handler = (void (*)(int)) SR_handler; - - // SR_signum is blocked by default. - // 4528190 - We also need to block pthread restart signal (32 on all - // supported Linux platforms). Note that LinuxThreads need to block - // this signal for all threads to work properly. So we don't have - // to use hard-coded signal number when setting up the mask. - pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); - - if (sigaction(SR_signum, &act, 0) == -1) { - return -1; - } - - // Save signal flag - os::Linux::set_our_sigflags(SR_signum, act.sa_flags); - return 0; -} - -static int SR_finalize() { - return 0; -} - - -// returns true on success and false on error - really an error is fatal -// but this seems the normal response to library errors -static bool do_suspend(OSThread* osthread) { - // mark as suspended and send signal - osthread->sr.set_suspend_action(SR_SUSPEND); - int status = pthread_kill(osthread->pthread_id(), SR_signum); - assert_status(status == 0, status, "pthread_kill"); - - // check status and wait until notified of suspension - if (status == 0) { - for (int i = 0; !osthread->sr.is_suspended(); i++) { - os::yield_all(i); - } - osthread->sr.set_suspend_action(SR_NONE); - return true; - } - else { - osthread->sr.set_suspend_action(SR_NONE); - return false; - } -} - -static void do_resume(OSThread* osthread) { - assert(osthread->sr.is_suspended(), "thread should be suspended"); - osthread->sr.set_suspend_action(SR_CONTINUE); - - int status = pthread_kill(osthread->pthread_id(), SR_signum); - assert_status(status == 0, status, "pthread_kill"); - // check status and wait unit notified of resumption - if (status == 0) { - for (int i = 0; osthread->sr.is_suspended(); i++) { - os::yield_all(i); - } - } - osthread->sr.set_suspend_action(SR_NONE); -} - -//////////////////////////////////////////////////////////////////////////////// -// interrupt support - -void os::interrupt(Thread* thread) { - assert(Thread::current() == thread || Threads_lock->owned_by_self(), - "possibility of dangling Thread pointer"); - - OSThread* osthread = thread->osthread(); - - if (!osthread->interrupted()) { - osthread->set_interrupted(true); - // More than one thread can get here with the same value of osthread, - // resulting in multiple notifications. We do, however, want the store - // to interrupted() to be visible to other threads before we execute unpark(). - OrderAccess::fence(); - ParkEvent * const slp = thread->_SleepEvent ; - if (slp != NULL) slp->unpark() ; - } - - // For JSR166. Unpark even if interrupt status already was set - if (thread->is_Java_thread()) - ((JavaThread*)thread)->parker()->unpark(); - - ParkEvent * ev = thread->_ParkEvent ; - if (ev != NULL) ev->unpark() ; - -} - -bool os::is_interrupted(Thread* thread, bool clear_interrupted) { - assert(Thread::current() == thread || Threads_lock->owned_by_self(), - "possibility of dangling Thread pointer"); - - OSThread* osthread = thread->osthread(); - - bool interrupted = osthread->interrupted(); - - if (interrupted && clear_interrupted) { - osthread->set_interrupted(false); - // consider thread->_SleepEvent->reset() ... optional optimization - } - - return interrupted; -} - -/////////////////////////////////////////////////////////////////////////////////// -// signal handling (except suspend/resume) - -// This routine may be used by user applications as a "hook" to catch signals. -// The user-defined signal handler must pass unrecognized signals to this -// routine, and if it returns true (non-zero), then the signal handler must -// return immediately. If the flag "abort_if_unrecognized" is true, then this -// routine will never retun false (zero), but instead will execute a VM panic -// routine kill the process. -// -// If this routine returns false, it is OK to call it again. This allows -// the user-defined signal handler to perform checks either before or after -// the VM performs its own checks. Naturally, the user code would be making -// a serious error if it tried to handle an exception (such as a null check -// or breakpoint) that the VM was generating for its own correct operation. -// -// This routine may recognize any of the following kinds of signals: -// SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. -// It should be consulted by handlers for any of those signals. -// -// The caller of this routine must pass in the three arguments supplied -// to the function referred to in the "sa_sigaction" (not the "sa_handler") -// field of the structure passed to sigaction(). This routine assumes that -// the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. -// -// Note that the VM will print warnings if it detects conflicting signal -// handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". -// -extern "C" JNIEXPORT int -JVM_handle_linux_signal(int signo, siginfo_t* siginfo, - void* ucontext, int abort_if_unrecognized); - -void signalHandler(int sig, siginfo_t* info, void* uc) { - assert(info != NULL && uc != NULL, "it must be old kernel"); - JVM_handle_linux_signal(sig, info, uc, true); -} - - -// This boolean allows users to forward their own non-matching signals -// to JVM_handle_linux_signal, harmlessly. -bool os::Linux::signal_handlers_are_installed = false; - -// For signal-chaining -struct sigaction os::Linux::sigact[MAXSIGNUM]; -unsigned int os::Linux::sigs = 0; -bool os::Linux::libjsig_is_loaded = false; -typedef struct sigaction *(*get_signal_t)(int); -get_signal_t os::Linux::get_signal_action = NULL; - -struct sigaction* os::Linux::get_chained_signal_action(int sig) { - struct sigaction *actp = NULL; - - if (libjsig_is_loaded) { - // Retrieve the old signal handler from libjsig - actp = (*get_signal_action)(sig); - } - if (actp == NULL) { - // Retrieve the preinstalled signal handler from jvm - actp = get_preinstalled_handler(sig); - } - - return actp; -} - -static bool call_chained_handler(struct sigaction *actp, int sig, - siginfo_t *siginfo, void *context) { - // Call the old signal handler - if (actp->sa_handler == SIG_DFL) { - // It's more reasonable to let jvm treat it as an unexpected exception - // instead of taking the default action. - return false; - } else if (actp->sa_handler != SIG_IGN) { - if ((actp->sa_flags & SA_NODEFER) == 0) { - // automaticlly block the signal - sigaddset(&(actp->sa_mask), sig); - } - - sa_handler_t hand; - sa_sigaction_t sa; - bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; - // retrieve the chained handler - if (siginfo_flag_set) { - sa = actp->sa_sigaction; - } else { - hand = actp->sa_handler; - } - - if ((actp->sa_flags & SA_RESETHAND) != 0) { - actp->sa_handler = SIG_DFL; - } - - // try to honor the signal mask - sigset_t oset; - pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); - - // call into the chained handler - if (siginfo_flag_set) { - (*sa)(sig, siginfo, context); - } else { - (*hand)(sig); - } - - // restore the signal mask - pthread_sigmask(SIG_SETMASK, &oset, 0); - } - // Tell jvm's signal handler the signal is taken care of. - return true; -} - -bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) { - bool chained = false; - // signal-chaining - if (UseSignalChaining) { - struct sigaction *actp = get_chained_signal_action(sig); - if (actp != NULL) { - chained = call_chained_handler(actp, sig, siginfo, context); - } - } - return chained; -} - -struct sigaction* os::Linux::get_preinstalled_handler(int sig) { - if ((( (unsigned int)1 << sig ) & sigs) != 0) { - return &sigact[sig]; - } - return NULL; -} - -void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) { - assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); - sigact[sig] = oldAct; - sigs |= (unsigned int)1 << sig; -} - -// for diagnostic -int os::Linux::sigflags[MAXSIGNUM]; - -int os::Linux::get_our_sigflags(int sig) { - assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); - return sigflags[sig]; -} - -void os::Linux::set_our_sigflags(int sig, int flags) { - assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); - sigflags[sig] = flags; -} - -void os::Linux::set_signal_handler(int sig, bool set_installed) { - // Check for overwrite. - struct sigaction oldAct; - sigaction(sig, (struct sigaction*)NULL, &oldAct); - - void* oldhand = oldAct.sa_sigaction - ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) - : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); - if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && - oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && - oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { - if (AllowUserSignalHandlers || !set_installed) { - // Do not overwrite; user takes responsibility to forward to us. - return; - } else if (UseSignalChaining) { - // save the old handler in jvm - save_preinstalled_handler(sig, oldAct); - // libjsig also interposes the sigaction() call below and saves the - // old sigaction on it own. - } else { - fatal(err_msg("Encountered unexpected pre-existing sigaction handler " - "%#lx for signal %d.", (long)oldhand, sig)); - } - } - - struct sigaction sigAct; - sigfillset(&(sigAct.sa_mask)); - sigAct.sa_handler = SIG_DFL; - if (!set_installed) { - sigAct.sa_flags = SA_SIGINFO|SA_RESTART; - } else { - sigAct.sa_sigaction = signalHandler; - sigAct.sa_flags = SA_SIGINFO|SA_RESTART; - } - // Save flags, which are set by ours - assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); - sigflags[sig] = sigAct.sa_flags; - - int ret = sigaction(sig, &sigAct, &oldAct); - assert(ret == 0, "check"); - - void* oldhand2 = oldAct.sa_sigaction - ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) - : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); - assert(oldhand2 == oldhand, "no concurrent signal handler installation"); -} - -// install signal handlers for signals that HotSpot needs to -// handle in order to support Java-level exception handling. - -void os::Linux::install_signal_handlers() { - if (!signal_handlers_are_installed) { - signal_handlers_are_installed = true; - - // signal-chaining - typedef void (*signal_setting_t)(); - signal_setting_t begin_signal_setting = NULL; - signal_setting_t end_signal_setting = NULL; - begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, - dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); - if (begin_signal_setting != NULL) { - end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, - dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); - get_signal_action = CAST_TO_FN_PTR(get_signal_t, - dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); - libjsig_is_loaded = true; - assert(UseSignalChaining, "should enable signal-chaining"); - } - if (libjsig_is_loaded) { - // Tell libjsig jvm is setting signal handlers - (*begin_signal_setting)(); - } - - set_signal_handler(SIGSEGV, true); - set_signal_handler(SIGPIPE, true); - set_signal_handler(SIGBUS, true); - set_signal_handler(SIGILL, true); - set_signal_handler(SIGFPE, true); - set_signal_handler(SIGXFSZ, true); - - if (libjsig_is_loaded) { - // Tell libjsig jvm finishes setting signal handlers - (*end_signal_setting)(); - } - - // We don't activate signal checker if libjsig is in place, we trust ourselves - // and if UserSignalHandler is installed all bets are off - if (CheckJNICalls) { - if (libjsig_is_loaded) { - tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); - check_signals = false; - } - if (AllowUserSignalHandlers) { - tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); - check_signals = false; - } - } - } -} - -// This is the fastest way to get thread cpu time on Linux. -// Returns cpu time (user+sys) for any thread, not only for current. -// POSIX compliant clocks are implemented in the kernels 2.6.16+. -// It might work on 2.6.10+ with a special kernel/glibc patch. -// For reference, please, see IEEE Std 1003.1-2004: -// http://www.unix.org/single_unix_specification - -jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) { - struct timespec tp; - int rc = os::Linux::clock_gettime(clockid, &tp); - assert(rc == 0, "clock_gettime is expected to return 0 code"); - - return (tp.tv_sec * SEC_IN_NANOSECS) + tp.tv_nsec; -} - -///// -// glibc on Linux platform uses non-documented flag -// to indicate, that some special sort of signal -// trampoline is used. -// We will never set this flag, and we should -// ignore this flag in our diagnostic -#ifdef SIGNIFICANT_SIGNAL_MASK -#undef SIGNIFICANT_SIGNAL_MASK -#endif -#define SIGNIFICANT_SIGNAL_MASK (~0x04000000) - -static const char* get_signal_handler_name(address handler, - char* buf, int buflen) { - int offset; - bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); - if (found) { - // skip directory names - const char *p1, *p2; - p1 = buf; - size_t len = strlen(os::file_separator()); - while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; - jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); - } else { - jio_snprintf(buf, buflen, PTR_FORMAT, handler); - } - return buf; -} - -static void print_signal_handler(outputStream* st, int sig, - char* buf, size_t buflen) { - struct sigaction sa; - - sigaction(sig, NULL, &sa); - - // See comment for SIGNIFICANT_SIGNAL_MASK define - sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; - - st->print("%s: ", os::exception_name(sig, buf, buflen)); - - address handler = (sa.sa_flags & SA_SIGINFO) - ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) - : CAST_FROM_FN_PTR(address, sa.sa_handler); - - if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { - st->print("SIG_DFL"); - } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { - st->print("SIG_IGN"); - } else { - st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); - } - - st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask); - - address rh = VMError::get_resetted_sighandler(sig); - // May be, handler was resetted by VMError? - if(rh != NULL) { - handler = rh; - sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; - } - - st->print(", sa_flags=" PTR32_FORMAT, sa.sa_flags); - - // Check: is it our handler? - if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || - handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { - // It is our signal handler - // check for flags, reset system-used one! - if((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) { - st->print( - ", flags was changed from " PTR32_FORMAT ", consider using jsig library", - os::Linux::get_our_sigflags(sig)); - } - } - st->cr(); -} - - -#define DO_SIGNAL_CHECK(sig) \ - if (!sigismember(&check_signal_done, sig)) \ - os::Linux::check_signal_handler(sig) - -// This method is a periodic task to check for misbehaving JNI applications -// under CheckJNI, we can add any periodic checks here - -void os::run_periodic_checks() { - - if (check_signals == false) return; - - // SEGV and BUS if overridden could potentially prevent - // generation of hs*.log in the event of a crash, debugging - // such a case can be very challenging, so we absolutely - // check the following for a good measure: - DO_SIGNAL_CHECK(SIGSEGV); - DO_SIGNAL_CHECK(SIGILL); - DO_SIGNAL_CHECK(SIGFPE); - DO_SIGNAL_CHECK(SIGBUS); - DO_SIGNAL_CHECK(SIGPIPE); - DO_SIGNAL_CHECK(SIGXFSZ); - - - // ReduceSignalUsage allows the user to override these handlers - // see comments at the very top and jvm_solaris.h - if (!ReduceSignalUsage) { - DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); - DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); - DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); - DO_SIGNAL_CHECK(BREAK_SIGNAL); - } - - DO_SIGNAL_CHECK(SR_signum); - DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); -} - -typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); - -static os_sigaction_t os_sigaction = NULL; - -void os::Linux::check_signal_handler(int sig) { - char buf[O_BUFLEN]; - address jvmHandler = NULL; - - - struct sigaction act; - if (os_sigaction == NULL) { - // only trust the default sigaction, in case it has been interposed - os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); - if (os_sigaction == NULL) return; - } - - os_sigaction(sig, (struct sigaction*)NULL, &act); - - - act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; - - address thisHandler = (act.sa_flags & SA_SIGINFO) - ? CAST_FROM_FN_PTR(address, act.sa_sigaction) - : CAST_FROM_FN_PTR(address, act.sa_handler) ; - - - switch(sig) { - case SIGSEGV: - case SIGBUS: - case SIGFPE: - case SIGPIPE: - case SIGILL: - case SIGXFSZ: - jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); - break; - - case SHUTDOWN1_SIGNAL: - case SHUTDOWN2_SIGNAL: - case SHUTDOWN3_SIGNAL: - case BREAK_SIGNAL: - jvmHandler = (address)user_handler(); - break; - - case INTERRUPT_SIGNAL: - jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); - break; - - default: - if (sig == SR_signum) { - jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); - } else { - return; - } - break; - } - - if (thisHandler != jvmHandler) { - tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); - tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); - tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); - // No need to check this sig any longer - sigaddset(&check_signal_done, sig); - } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) { - tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); - tty->print("expected:" PTR32_FORMAT, os::Linux::get_our_sigflags(sig)); - tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); - // No need to check this sig any longer - sigaddset(&check_signal_done, sig); - } - - // Dump all the signal - if (sigismember(&check_signal_done, sig)) { - print_signal_handlers(tty, buf, O_BUFLEN); - } -} - -extern void report_error(char* file_name, int line_no, char* title, char* format, ...); - -extern bool signal_name(int signo, char* buf, size_t len); - -const char* os::exception_name(int exception_code, char* buf, size_t size) { - if (0 < exception_code && exception_code <= SIGRTMAX) { - // signal - if (!signal_name(exception_code, buf, size)) { - jio_snprintf(buf, size, "SIG%d", exception_code); - } - return buf; - } else { - return NULL; - } -} - -// this is called _before_ the most of global arguments have been parsed -void os::init(void) { - char dummy; /* used to get a guess on initial stack address */ -// first_hrtime = gethrtime(); - - // With LinuxThreads the JavaMain thread pid (primordial thread) - // is different than the pid of the java launcher thread. - // So, on Linux, the launcher thread pid is passed to the VM - // via the sun.java.launcher.pid property. - // Use this property instead of getpid() if it was correctly passed. - // See bug 6351349. - pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); - - _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); - - clock_tics_per_sec = sysconf(_SC_CLK_TCK); - - init_random(1234567); - - ThreadCritical::initialize(); - - Linux::set_page_size(sysconf(_SC_PAGESIZE)); - if (Linux::page_size() == -1) { - fatal(err_msg("os_linux.cpp: os::init: sysconf failed (%s)", - strerror(errno))); - } - init_page_sizes((size_t) Linux::page_size()); - - Linux::initialize_system_info(); - - // main_thread points to the aboriginal thread - Linux::_main_thread = pthread_self(); - - Linux::clock_init(); - initial_time_count = os::elapsed_counter(); - pthread_mutex_init(&dl_mutex, NULL); -} - -// To install functions for atexit system call -extern "C" { - static void perfMemory_exit_helper() { - perfMemory_exit(); - } -} - -// this is called _after_ the global arguments have been parsed -jint os::init_2(void) -{ - Linux::fast_thread_clock_init(); - - // Allocate a single page and mark it as readable for safepoint polling - address polling_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); - guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" ); - - os::set_polling_page( polling_page ); - -#ifndef PRODUCT - if(Verbose && PrintMiscellaneous) - tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page); -#endif - - if (!UseMembar) { - address mem_serialize_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); - guarantee( mem_serialize_page != NULL, "mmap Failed for memory serialize page"); - os::set_memory_serialize_page( mem_serialize_page ); - -#ifndef PRODUCT - if(Verbose && PrintMiscellaneous) - tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page); -#endif - } - - os::large_page_init(); - - // initialize suspend/resume support - must do this before signal_sets_init() - if (SR_initialize() != 0) { - perror("SR_initialize failed"); - return JNI_ERR; - } - - Linux::signal_sets_init(); - Linux::install_signal_handlers(); - - // Check minimum allowable stack size for thread creation and to initialize - // the java system classes, including StackOverflowError - depends on page - // size. Add a page for compiler2 recursion in main thread. - // Add in 2*BytesPerWord times page size to account for VM stack during - // class initialization depending on 32 or 64 bit VM. - os::Linux::min_stack_allowed = MAX2(os::Linux::min_stack_allowed, - (size_t)(StackYellowPages+StackRedPages+StackShadowPages+ - 2*BytesPerWord COMPILER2_PRESENT(+1)) * Linux::page_size()); - - size_t threadStackSizeInBytes = ThreadStackSize * K; - if (threadStackSizeInBytes != 0 && - threadStackSizeInBytes < os::Linux::min_stack_allowed) { - tty->print_cr("\nThe stack size specified is too small, " - "Specify at least %dk", - os::Linux::min_stack_allowed/ K); - return JNI_ERR; - } - - // Make the stack size a multiple of the page size so that - // the yellow/red zones can be guarded. - JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, - vm_page_size())); - - Linux::capture_initial_stack(JavaThread::stack_size_at_create()); - - Linux::libpthread_init(); - if (PrintMiscellaneous && (Verbose || WizardMode)) { - tty->print_cr("[HotSpot is running with %s, %s(%s)]\n", - Linux::glibc_version(), Linux::libpthread_version(), - Linux::is_floating_stack() ? "floating stack" : "fixed stack"); - } - - if (UseNUMA) { - if (!Linux::libnuma_init()) { - UseNUMA = false; - } else { - if ((Linux::numa_max_node() < 1)) { - // There's only one node(they start from 0), disable NUMA. - UseNUMA = false; - } - } - // With SHM large pages we cannot uncommit a page, so there's not way - // we can make the adaptive lgrp chunk resizing work. If the user specified - // both UseNUMA and UseLargePages (or UseSHM) on the command line - warn and - // disable adaptive resizing. - if (UseNUMA && UseLargePages && UseSHM) { - if (!FLAG_IS_DEFAULT(UseNUMA)) { - if (FLAG_IS_DEFAULT(UseLargePages) && FLAG_IS_DEFAULT(UseSHM)) { - UseLargePages = false; - } else { - warning("UseNUMA is not fully compatible with SHM large pages, disabling adaptive resizing"); - UseAdaptiveSizePolicy = false; - UseAdaptiveNUMAChunkSizing = false; - } - } else { - UseNUMA = false; - } - } - if (!UseNUMA && ForceNUMA) { - UseNUMA = true; - } - } - - if (MaxFDLimit) { - // set the number of file descriptors to max. print out error - // if getrlimit/setrlimit fails but continue regardless. - struct rlimit nbr_files; - int status = getrlimit(RLIMIT_NOFILE, &nbr_files); - if (status != 0) { - if (PrintMiscellaneous && (Verbose || WizardMode)) - perror("os::init_2 getrlimit failed"); - } else { - nbr_files.rlim_cur = nbr_files.rlim_max; - status = setrlimit(RLIMIT_NOFILE, &nbr_files); - if (status != 0) { - if (PrintMiscellaneous && (Verbose || WizardMode)) - perror("os::init_2 setrlimit failed"); - } - } - } - - // Initialize lock used to serialize thread creation (see os::create_thread) - Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false)); - - // at-exit methods are called in the reverse order of their registration. - // atexit functions are called on return from main or as a result of a - // call to exit(3C). There can be only 32 of these functions registered - // and atexit() does not set errno. - - if (PerfAllowAtExitRegistration) { - // only register atexit functions if PerfAllowAtExitRegistration is set. - // atexit functions can be delayed until process exit time, which - // can be problematic for embedded VM situations. Embedded VMs should - // call DestroyJavaVM() to assure that VM resources are released. - - // note: perfMemory_exit_helper atexit function may be removed in - // the future if the appropriate cleanup code can be added to the - // VM_Exit VMOperation's doit method. - if (atexit(perfMemory_exit_helper) != 0) { - warning("os::init2 atexit(perfMemory_exit_helper) failed"); - } - } - - // initialize thread priority policy - prio_init(); - - return JNI_OK; -} - -// this is called at the end of vm_initialization -void os::init_3(void) -{ -#ifdef JAVASE_EMBEDDED - // Start the MemNotifyThread - if (LowMemoryProtection) { - MemNotifyThread::start(); - } - return; -#endif -} - -// Mark the polling page as unreadable -void os::make_polling_page_unreadable(void) { - if( !guard_memory((char*)_polling_page, Linux::page_size()) ) - fatal("Could not disable polling page"); -}; - -// Mark the polling page as readable -void os::make_polling_page_readable(void) { - if( !linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) { - fatal("Could not enable polling page"); - } -}; - -int os::active_processor_count() { - // Linux doesn't yet have a (official) notion of processor sets, - // so just return the number of online processors. - int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN); - assert(online_cpus > 0 && online_cpus <= processor_count(), "sanity check"); - return online_cpus; -} - -bool os::distribute_processes(uint length, uint* distribution) { - // Not yet implemented. - return false; -} - -bool os::bind_to_processor(uint processor_id) { - // Not yet implemented. - return false; -} - -/// - -// Suspends the target using the signal mechanism and then grabs the PC before -// resuming the target. Used by the flat-profiler only -ExtendedPC os::get_thread_pc(Thread* thread) { - // Make sure that it is called by the watcher for the VMThread - assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); - assert(thread->is_VM_thread(), "Can only be called for VMThread"); - - ExtendedPC epc; - - OSThread* osthread = thread->osthread(); - if (do_suspend(osthread)) { - if (osthread->ucontext() != NULL) { - epc = os::Linux::ucontext_get_pc(osthread->ucontext()); - } else { - // NULL context is unexpected, double-check this is the VMThread - guarantee(thread->is_VM_thread(), "can only be called for VMThread"); - } - do_resume(osthread); - } - // failure means pthread_kill failed for some reason - arguably this is - // a fatal problem, but such problems are ignored elsewhere - - return epc; -} - -int os::Linux::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime) -{ - if (is_NPTL()) { - return pthread_cond_timedwait(_cond, _mutex, _abstime); - } else { -#ifndef IA64 - // 6292965: LinuxThreads pthread_cond_timedwait() resets FPU control - // word back to default 64bit precision if condvar is signaled. Java - // wants 53bit precision. Save and restore current value. - int fpu = get_fpu_control_word(); -#endif // IA64 - int status = pthread_cond_timedwait(_cond, _mutex, _abstime); -#ifndef IA64 - set_fpu_control_word(fpu); -#endif // IA64 - return status; - } -} - -//////////////////////////////////////////////////////////////////////////////// -// debug support - -static address same_page(address x, address y) { - int page_bits = -os::vm_page_size(); - if ((intptr_t(x) & page_bits) == (intptr_t(y) & page_bits)) - return x; - else if (x > y) - return (address)(intptr_t(y) | ~page_bits) + 1; - else - return (address)(intptr_t(y) & page_bits); -} - -bool os::find(address addr, outputStream* st) { - Dl_info dlinfo; - memset(&dlinfo, 0, sizeof(dlinfo)); - if (dladdr(addr, &dlinfo)) { - st->print(PTR_FORMAT ": ", addr); - if (dlinfo.dli_sname != NULL) { - st->print("%s+%#x", dlinfo.dli_sname, - addr - (intptr_t)dlinfo.dli_saddr); - } else if (dlinfo.dli_fname) { - st->print("", addr - (intptr_t)dlinfo.dli_fbase); - } else { - st->print(""); - } - if (dlinfo.dli_fname) { - st->print(" in %s", dlinfo.dli_fname); - } - if (dlinfo.dli_fbase) { - st->print(" at " PTR_FORMAT, dlinfo.dli_fbase); - } - st->cr(); - - if (Verbose) { - // decode some bytes around the PC - address begin = same_page(addr-40, addr); - address end = same_page(addr+40, addr); - address lowest = (address) dlinfo.dli_sname; - if (!lowest) lowest = (address) dlinfo.dli_fbase; - if (begin < lowest) begin = lowest; - Dl_info dlinfo2; - if (dladdr(end, &dlinfo2) && dlinfo2.dli_saddr != dlinfo.dli_saddr - && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) - end = (address) dlinfo2.dli_saddr; - Disassembler::decode(begin, end, st); - } - return true; - } - return false; -} - -//////////////////////////////////////////////////////////////////////////////// -// misc - -// This does not do anything on Linux. This is basically a hook for being -// able to use structured exception handling (thread-local exception filters) -// on, e.g., Win32. -void -os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, - JavaCallArguments* args, Thread* thread) { - f(value, method, args, thread); -} - -void os::print_statistics() { -} - -int os::message_box(const char* title, const char* message) { - int i; - fdStream err(defaultStream::error_fd()); - for (i = 0; i < 78; i++) err.print_raw("="); - err.cr(); - err.print_raw_cr(title); - for (i = 0; i < 78; i++) err.print_raw("-"); - err.cr(); - err.print_raw_cr(message); - for (i = 0; i < 78; i++) err.print_raw("="); - err.cr(); - - char buf[16]; - // Prevent process from exiting upon "read error" without consuming all CPU - while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } - - return buf[0] == 'y' || buf[0] == 'Y'; -} - -int os::stat(const char *path, struct stat *sbuf) { - char pathbuf[MAX_PATH]; - if (strlen(path) > MAX_PATH - 1) { - errno = ENAMETOOLONG; - return -1; - } - os::native_path(strcpy(pathbuf, path)); - return ::stat(pathbuf, sbuf); -} - -bool os::check_heap(bool force) { - return true; -} - -int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) { - return ::vsnprintf(buf, count, format, args); -} - -// Is a (classpath) directory empty? -bool os::dir_is_empty(const char* path) { - DIR *dir = NULL; - struct dirent *ptr; - - dir = opendir(path); - if (dir == NULL) return true; - - /* Scan the directory */ - bool result = true; - char buf[sizeof(struct dirent) + MAX_PATH]; - while (result && (ptr = ::readdir(dir)) != NULL) { - if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { - result = false; - } - } - closedir(dir); - return result; -} - -// This code originates from JDK's sysOpen and open64_w -// from src/solaris/hpi/src/system_md.c - -#ifndef O_DELETE -#define O_DELETE 0x10000 -#endif - -// Open a file. Unlink the file immediately after open returns -// if the specified oflag has the O_DELETE flag set. -// O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c - -int os::open(const char *path, int oflag, int mode) { - - if (strlen(path) > MAX_PATH - 1) { - errno = ENAMETOOLONG; - return -1; - } - int fd; - int o_delete = (oflag & O_DELETE); - oflag = oflag & ~O_DELETE; - - fd = ::open64(path, oflag, mode); - if (fd == -1) return -1; - - //If the open succeeded, the file might still be a directory - { - struct stat64 buf64; - int ret = ::fstat64(fd, &buf64); - int st_mode = buf64.st_mode; - - if (ret != -1) { - if ((st_mode & S_IFMT) == S_IFDIR) { - errno = EISDIR; - ::close(fd); - return -1; - } - } else { - ::close(fd); - return -1; - } - } - - /* - * All file descriptors that are opened in the JVM and not - * specifically destined for a subprocess should have the - * close-on-exec flag set. If we don't set it, then careless 3rd - * party native code might fork and exec without closing all - * appropriate file descriptors (e.g. as we do in closeDescriptors in - * UNIXProcess.c), and this in turn might: - * - * - cause end-of-file to fail to be detected on some file - * descriptors, resulting in mysterious hangs, or - * - * - might cause an fopen in the subprocess to fail on a system - * suffering from bug 1085341. - * - * (Yes, the default setting of the close-on-exec flag is a Unix - * design flaw) - * - * See: - * 1085341: 32-bit stdio routines should support file descriptors >255 - * 4843136: (process) pipe file descriptor from Runtime.exec not being closed - * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 - */ -#ifdef FD_CLOEXEC - { - int flags = ::fcntl(fd, F_GETFD); - if (flags != -1) - ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); - } -#endif - - if (o_delete != 0) { - ::unlink(path); - } - return fd; -} - - -// create binary file, rewriting existing file if required -int os::create_binary_file(const char* path, bool rewrite_existing) { - int oflags = O_WRONLY | O_CREAT; - if (!rewrite_existing) { - oflags |= O_EXCL; - } - return ::open64(path, oflags, S_IREAD | S_IWRITE); -} - -// return current position of file pointer -jlong os::current_file_offset(int fd) { - return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR); -} - -// move file pointer to the specified offset -jlong os::seek_to_file_offset(int fd, jlong offset) { - return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET); -} - -// This code originates from JDK's sysAvailable -// from src/solaris/hpi/src/native_threads/src/sys_api_td.c - -int os::available(int fd, jlong *bytes) { - jlong cur, end; - int mode; - struct stat64 buf64; - - if (::fstat64(fd, &buf64) >= 0) { - mode = buf64.st_mode; - if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { - /* - * XXX: is the following call interruptible? If so, this might - * need to go through the INTERRUPT_IO() wrapper as for other - * blocking, interruptible calls in this file. - */ - int n; - if (::ioctl(fd, FIONREAD, &n) >= 0) { - *bytes = n; - return 1; - } - } - } - if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) { - return 0; - } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) { - return 0; - } else if (::lseek64(fd, cur, SEEK_SET) == -1) { - return 0; - } - *bytes = end - cur; - return 1; -} - -int os::socket_available(int fd, jint *pbytes) { - // Linux doc says EINTR not returned, unlike Solaris - int ret = ::ioctl(fd, FIONREAD, pbytes); - - //%% note ioctl can return 0 when successful, JVM_SocketAvailable - // is expected to return 0 on failure and 1 on success to the jdk. - return (ret < 0) ? 0 : 1; -} - -// Map a block of memory. -char* os::map_memory(int fd, const char* file_name, size_t file_offset, - char *addr, size_t bytes, bool read_only, - bool allow_exec) { - int prot; - int flags; - - if (read_only) { - prot = PROT_READ; - flags = MAP_SHARED; - } else { - prot = PROT_READ | PROT_WRITE; - flags = MAP_PRIVATE; - } - - if (allow_exec) { - prot |= PROT_EXEC; - } - - if (addr != NULL) { - flags |= MAP_FIXED; - } - - char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, - fd, file_offset); - if (mapped_address == MAP_FAILED) { - return NULL; - } - return mapped_address; -} - - -// Remap a block of memory. -char* os::remap_memory(int fd, const char* file_name, size_t file_offset, - char *addr, size_t bytes, bool read_only, - bool allow_exec) { - // same as map_memory() on this OS - return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, - allow_exec); -} - - -// Unmap a block of memory. -bool os::unmap_memory(char* addr, size_t bytes) { - return munmap(addr, bytes) == 0; -} - -static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time); - -static clockid_t thread_cpu_clockid(Thread* thread) { - pthread_t tid = thread->osthread()->pthread_id(); - clockid_t clockid; - - // Get thread clockid - int rc = os::Linux::pthread_getcpuclockid(tid, &clockid); - assert(rc == 0, "pthread_getcpuclockid is expected to return 0 code"); - return clockid; -} - -// current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) -// are used by JVM M&M and JVMTI to get user+sys or user CPU time -// of a thread. -// -// current_thread_cpu_time() and thread_cpu_time(Thread*) returns -// the fast estimate available on the platform. - -jlong os::current_thread_cpu_time() { - if (os::Linux::supports_fast_thread_cpu_time()) { - return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); - } else { - // return user + sys since the cost is the same - return slow_thread_cpu_time(Thread::current(), true /* user + sys */); - } -} - -jlong os::thread_cpu_time(Thread* thread) { - // consistent with what current_thread_cpu_time() returns - if (os::Linux::supports_fast_thread_cpu_time()) { - return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); - } else { - return slow_thread_cpu_time(thread, true /* user + sys */); - } -} - -jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { - if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { - return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); - } else { - return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time); - } -} - -jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { - if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { - return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); - } else { - return slow_thread_cpu_time(thread, user_sys_cpu_time); - } -} - -// -// -1 on error. -// - -static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { - static bool proc_pid_cpu_avail = true; - static bool proc_task_unchecked = true; - static const char *proc_stat_path = "/proc/%d/stat"; - pid_t tid = thread->osthread()->thread_id(); - int i; - char *s; - char stat[2048]; - int statlen; - char proc_name[64]; - int count; - long sys_time, user_time; - char string[64]; - char cdummy; - int idummy; - long ldummy; - FILE *fp; - - // We first try accessing /proc//cpu since this is faster to - // process. If this file is not present (linux kernels 2.5 and above) - // then we open /proc//stat. - if ( proc_pid_cpu_avail ) { - sprintf(proc_name, "/proc/%d/cpu", tid); - fp = fopen(proc_name, "r"); - if ( fp != NULL ) { - count = fscanf( fp, "%s %lu %lu\n", string, &user_time, &sys_time); - fclose(fp); - if ( count != 3 ) return -1; - - if (user_sys_cpu_time) { - return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); - } else { - return (jlong)user_time * (1000000000 / clock_tics_per_sec); - } - } - else proc_pid_cpu_avail = false; - } - - // The /proc//stat aggregates per-process usage on - // new Linux kernels 2.6+ where NPTL is supported. - // The /proc/self/task//stat still has the per-thread usage. - // See bug 6328462. - // There can be no directory /proc/self/task on kernels 2.4 with NPTL - // and possibly in some other cases, so we check its availability. - if (proc_task_unchecked && os::Linux::is_NPTL()) { - // This is executed only once - proc_task_unchecked = false; - fp = fopen("/proc/self/task", "r"); - if (fp != NULL) { - proc_stat_path = "/proc/self/task/%d/stat"; - fclose(fp); - } - } - - sprintf(proc_name, proc_stat_path, tid); - fp = fopen(proc_name, "r"); - if ( fp == NULL ) return -1; - statlen = fread(stat, 1, 2047, fp); - stat[statlen] = '\0'; - fclose(fp); - - // Skip pid and the command string. Note that we could be dealing with - // weird command names, e.g. user could decide to rename java launcher - // to "java 1.4.2 :)", then the stat file would look like - // 1234 (java 1.4.2 :)) R ... ... - // We don't really need to know the command string, just find the last - // occurrence of ")" and then start parsing from there. See bug 4726580. - s = strrchr(stat, ')'); - i = 0; - if (s == NULL ) return -1; - - // Skip blank chars - do s++; while (isspace(*s)); - - count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu", - &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy, - &ldummy, &ldummy, &ldummy, &ldummy, &ldummy, - &user_time, &sys_time); - if ( count != 13 ) return -1; - if (user_sys_cpu_time) { - return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); - } else { - return (jlong)user_time * (1000000000 / clock_tics_per_sec); - } -} - -void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { - info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits - info_ptr->may_skip_backward = false; // elapsed time not wall time - info_ptr->may_skip_forward = false; // elapsed time not wall time - info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned -} - -void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { - info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits - info_ptr->may_skip_backward = false; // elapsed time not wall time - info_ptr->may_skip_forward = false; // elapsed time not wall time - info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned -} - -bool os::is_thread_cpu_time_supported() { - return true; -} - -// System loadavg support. Returns -1 if load average cannot be obtained. -// Linux doesn't yet have a (official) notion of processor sets, -// so just return the system wide load average. -int os::loadavg(double loadavg[], int nelem) { - return ::getloadavg(loadavg, nelem); -} - -void os::pause() { - char filename[MAX_PATH]; - if (PauseAtStartupFile && PauseAtStartupFile[0]) { - jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); - } else { - jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); - } - - int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); - if (fd != -1) { - struct stat buf; - ::close(fd); - while (::stat(filename, &buf) == 0) { - (void)::poll(NULL, 0, 100); - } - } else { - jio_fprintf(stderr, - "Could not open pause file '%s', continuing immediately.\n", filename); - } -} - - -// Refer to the comments in os_solaris.cpp park-unpark. -// -// Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can -// hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. -// For specifics regarding the bug see GLIBC BUGID 261237 : -// http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. -// Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future -// will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar -// is used. (The simple C test-case provided in the GLIBC bug report manifests the -// hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() -// and monitorenter when we're using 1-0 locking. All those operations may result in -// calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version -// of libpthread avoids the problem, but isn't practical. -// -// Possible remedies: -// -// 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. -// This is palliative and probabilistic, however. If the thread is preempted -// between the call to compute_abstime() and pthread_cond_timedwait(), more -// than the minimum period may have passed, and the abstime may be stale (in the -// past) resultin in a hang. Using this technique reduces the odds of a hang -// but the JVM is still vulnerable, particularly on heavily loaded systems. -// -// 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead -// of the usual flag-condvar-mutex idiom. The write side of the pipe is set -// NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) -// reduces to poll()+read(). This works well, but consumes 2 FDs per extant -// thread. -// -// 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread -// that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing -// a timeout request to the chron thread and then blocking via pthread_cond_wait(). -// This also works well. In fact it avoids kernel-level scalability impediments -// on certain platforms that don't handle lots of active pthread_cond_timedwait() -// timers in a graceful fashion. -// -// 4. When the abstime value is in the past it appears that control returns -// correctly from pthread_cond_timedwait(), but the condvar is left corrupt. -// Subsequent timedwait/wait calls may hang indefinitely. Given that, we -// can avoid the problem by reinitializing the condvar -- by cond_destroy() -// followed by cond_init() -- after all calls to pthread_cond_timedwait(). -// It may be possible to avoid reinitialization by checking the return -// value from pthread_cond_timedwait(). In addition to reinitializing the -// condvar we must establish the invariant that cond_signal() is only called -// within critical sections protected by the adjunct mutex. This prevents -// cond_signal() from "seeing" a condvar that's in the midst of being -// reinitialized or that is corrupt. Sadly, this invariant obviates the -// desirable signal-after-unlock optimization that avoids futile context switching. -// -// I'm also concerned that some versions of NTPL might allocate an auxilliary -// structure when a condvar is used or initialized. cond_destroy() would -// release the helper structure. Our reinitialize-after-timedwait fix -// put excessive stress on malloc/free and locks protecting the c-heap. -// -// We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. -// It may be possible to refine (4) by checking the kernel and NTPL verisons -// and only enabling the work-around for vulnerable environments. - -// utility to compute the abstime argument to timedwait: -// millis is the relative timeout time -// abstime will be the absolute timeout time -// TODO: replace compute_abstime() with unpackTime() - -static struct timespec* compute_abstime(timespec* abstime, jlong millis) { - if (millis < 0) millis = 0; - struct timeval now; - int status = gettimeofday(&now, NULL); - assert(status == 0, "gettimeofday"); - jlong seconds = millis / 1000; - millis %= 1000; - if (seconds > 50000000) { // see man cond_timedwait(3T) - seconds = 50000000; - } - abstime->tv_sec = now.tv_sec + seconds; - long usec = now.tv_usec + millis * 1000; - if (usec >= 1000000) { - abstime->tv_sec += 1; - usec -= 1000000; - } - abstime->tv_nsec = usec * 1000; - return abstime; -} - - -// Test-and-clear _Event, always leaves _Event set to 0, returns immediately. -// Conceptually TryPark() should be equivalent to park(0). - -int os::PlatformEvent::TryPark() { - for (;;) { - const int v = _Event ; - guarantee ((v == 0) || (v == 1), "invariant") ; - if (Atomic::cmpxchg (0, &_Event, v) == v) return v ; - } -} - -void os::PlatformEvent::park() { // AKA "down()" - // Invariant: Only the thread associated with the Event/PlatformEvent - // may call park(). - // TODO: assert that _Assoc != NULL or _Assoc == Self - int v ; - for (;;) { - v = _Event ; - if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; - } - guarantee (v >= 0, "invariant") ; - if (v == 0) { - // Do this the hard way by blocking ... - int status = pthread_mutex_lock(_mutex); - assert_status(status == 0, status, "mutex_lock"); - guarantee (_nParked == 0, "invariant") ; - ++ _nParked ; - while (_Event < 0) { - status = pthread_cond_wait(_cond, _mutex); - // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... - // Treat this the same as if the wait was interrupted - if (status == ETIME) { status = EINTR; } - assert_status(status == 0 || status == EINTR, status, "cond_wait"); - } - -- _nParked ; - - // In theory we could move the ST of 0 into _Event past the unlock(), - // but then we'd need a MEMBAR after the ST. - _Event = 0 ; - status = pthread_mutex_unlock(_mutex); - assert_status(status == 0, status, "mutex_unlock"); - } - guarantee (_Event >= 0, "invariant") ; -} - -int os::PlatformEvent::park(jlong millis) { - guarantee (_nParked == 0, "invariant") ; - - int v ; - for (;;) { - v = _Event ; - if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; - } - guarantee (v >= 0, "invariant") ; - if (v != 0) return OS_OK ; - - // We do this the hard way, by blocking the thread. - // Consider enforcing a minimum timeout value. - struct timespec abst; - compute_abstime(&abst, millis); - - int ret = OS_TIMEOUT; - int status = pthread_mutex_lock(_mutex); - assert_status(status == 0, status, "mutex_lock"); - guarantee (_nParked == 0, "invariant") ; - ++_nParked ; - - // Object.wait(timo) will return because of - // (a) notification - // (b) timeout - // (c) thread.interrupt - // - // Thread.interrupt and object.notify{All} both call Event::set. - // That is, we treat thread.interrupt as a special case of notification. - // The underlying Solaris implementation, cond_timedwait, admits - // spurious/premature wakeups, but the JLS/JVM spec prevents the - // JVM from making those visible to Java code. As such, we must - // filter out spurious wakeups. We assume all ETIME returns are valid. - // - // TODO: properly differentiate simultaneous notify+interrupt. - // In that case, we should propagate the notify to another waiter. - - while (_Event < 0) { - status = os::Linux::safe_cond_timedwait(_cond, _mutex, &abst); - if (status != 0 && WorkAroundNPTLTimedWaitHang) { - pthread_cond_destroy (_cond); - pthread_cond_init (_cond, NULL) ; - } - assert_status(status == 0 || status == EINTR || - status == ETIME || status == ETIMEDOUT, - status, "cond_timedwait"); - if (!FilterSpuriousWakeups) break ; // previous semantics - if (status == ETIME || status == ETIMEDOUT) break ; - // We consume and ignore EINTR and spurious wakeups. - } - --_nParked ; - if (_Event >= 0) { - ret = OS_OK; - } - _Event = 0 ; - status = pthread_mutex_unlock(_mutex); - assert_status(status == 0, status, "mutex_unlock"); - assert (_nParked == 0, "invariant") ; - return ret; -} - -void os::PlatformEvent::unpark() { - int v, AnyWaiters ; - for (;;) { - v = _Event ; - if (v > 0) { - // The LD of _Event could have reordered or be satisfied - // by a read-aside from this processor's write buffer. - // To avoid problems execute a barrier and then - // ratify the value. - OrderAccess::fence() ; - if (_Event == v) return ; - continue ; - } - if (Atomic::cmpxchg (v+1, &_Event, v) == v) break ; - } - if (v < 0) { - // Wait for the thread associated with the event to vacate - int status = pthread_mutex_lock(_mutex); - assert_status(status == 0, status, "mutex_lock"); - AnyWaiters = _nParked ; - assert (AnyWaiters == 0 || AnyWaiters == 1, "invariant") ; - if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { - AnyWaiters = 0 ; - pthread_cond_signal (_cond); - } - status = pthread_mutex_unlock(_mutex); - assert_status(status == 0, status, "mutex_unlock"); - if (AnyWaiters != 0) { - status = pthread_cond_signal(_cond); - assert_status(status == 0, status, "cond_signal"); - } - } - - // Note that we signal() _after dropping the lock for "immortal" Events. - // This is safe and avoids a common class of futile wakeups. In rare - // circumstances this can cause a thread to return prematurely from - // cond_{timed}wait() but the spurious wakeup is benign and the victim will - // simply re-test the condition and re-park itself. -} - - -// JSR166 -// ------------------------------------------------------- - -/* - * The solaris and linux implementations of park/unpark are fairly - * conservative for now, but can be improved. They currently use a - * mutex/condvar pair, plus a a count. - * Park decrements count if > 0, else does a condvar wait. Unpark - * sets count to 1 and signals condvar. Only one thread ever waits - * on the condvar. Contention seen when trying to park implies that someone - * is unparking you, so don't wait. And spurious returns are fine, so there - * is no need to track notifications. - */ - - -#define NANOSECS_PER_SEC 1000000000 -#define NANOSECS_PER_MILLISEC 1000000 -#define MAX_SECS 100000000 -/* - * This code is common to linux and solaris and will be moved to a - * common place in dolphin. - * - * The passed in time value is either a relative time in nanoseconds - * or an absolute time in milliseconds. Either way it has to be unpacked - * into suitable seconds and nanoseconds components and stored in the - * given timespec structure. - * Given time is a 64-bit value and the time_t used in the timespec is only - * a signed-32-bit value (except on 64-bit Linux) we have to watch for - * overflow if times way in the future are given. Further on Solaris versions - * prior to 10 there is a restriction (see cond_timedwait) that the specified - * number of seconds, in abstime, is less than current_time + 100,000,000. - * As it will be 28 years before "now + 100000000" will overflow we can - * ignore overflow and just impose a hard-limit on seconds using the value - * of "now + 100,000,000". This places a limit on the timeout of about 3.17 - * years from "now". - */ - -static void unpackTime(timespec* absTime, bool isAbsolute, jlong time) { - assert (time > 0, "convertTime"); - - struct timeval now; - int status = gettimeofday(&now, NULL); - assert(status == 0, "gettimeofday"); - - time_t max_secs = now.tv_sec + MAX_SECS; - - if (isAbsolute) { - jlong secs = time / 1000; - if (secs > max_secs) { - absTime->tv_sec = max_secs; - } - else { - absTime->tv_sec = secs; - } - absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; - } - else { - jlong secs = time / NANOSECS_PER_SEC; - if (secs >= MAX_SECS) { - absTime->tv_sec = max_secs; - absTime->tv_nsec = 0; - } - else { - absTime->tv_sec = now.tv_sec + secs; - absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; - if (absTime->tv_nsec >= NANOSECS_PER_SEC) { - absTime->tv_nsec -= NANOSECS_PER_SEC; - ++absTime->tv_sec; // note: this must be <= max_secs - } - } - } - assert(absTime->tv_sec >= 0, "tv_sec < 0"); - assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); - assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); - assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); -} - -void Parker::park(bool isAbsolute, jlong time) { - // Optional fast-path check: - // Return immediately if a permit is available. - if (_counter > 0) { - _counter = 0 ; - OrderAccess::fence(); - return ; - } - - Thread* thread = Thread::current(); - assert(thread->is_Java_thread(), "Must be JavaThread"); - JavaThread *jt = (JavaThread *)thread; - - // Optional optimization -- avoid state transitions if there's an interrupt pending. - // Check interrupt before trying to wait - if (Thread::is_interrupted(thread, false)) { - return; - } - - // Next, demultiplex/decode time arguments - timespec absTime; - if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all - return; - } - if (time > 0) { - unpackTime(&absTime, isAbsolute, time); - } - - - // Enter safepoint region - // Beware of deadlocks such as 6317397. - // The per-thread Parker:: mutex is a classic leaf-lock. - // In particular a thread must never block on the Threads_lock while - // holding the Parker:: mutex. If safepoints are pending both the - // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. - ThreadBlockInVM tbivm(jt); - - // Don't wait if cannot get lock since interference arises from - // unblocking. Also. check interrupt before trying wait - if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { - return; - } - - int status ; - if (_counter > 0) { // no wait needed - _counter = 0; - status = pthread_mutex_unlock(_mutex); - assert (status == 0, "invariant") ; - OrderAccess::fence(); - return; - } - -#ifdef ASSERT - // Don't catch signals while blocked; let the running threads have the signals. - // (This allows a debugger to break into the running thread.) - sigset_t oldsigs; - sigset_t* allowdebug_blocked = os::Linux::allowdebug_blocked_signals(); - pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); -#endif - - OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); - jt->set_suspend_equivalent(); - // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() - - if (time == 0) { - status = pthread_cond_wait (_cond, _mutex) ; - } else { - status = os::Linux::safe_cond_timedwait (_cond, _mutex, &absTime) ; - if (status != 0 && WorkAroundNPTLTimedWaitHang) { - pthread_cond_destroy (_cond) ; - pthread_cond_init (_cond, NULL); - } - } - assert_status(status == 0 || status == EINTR || - status == ETIME || status == ETIMEDOUT, - status, "cond_timedwait"); - -#ifdef ASSERT - pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); -#endif - - _counter = 0 ; - status = pthread_mutex_unlock(_mutex) ; - assert_status(status == 0, status, "invariant") ; - // If externally suspended while waiting, re-suspend - if (jt->handle_special_suspend_equivalent_condition()) { - jt->java_suspend_self(); - } - - OrderAccess::fence(); -} - -void Parker::unpark() { - int s, status ; - status = pthread_mutex_lock(_mutex); - assert (status == 0, "invariant") ; - s = _counter; - _counter = 1; - if (s < 1) { - if (WorkAroundNPTLTimedWaitHang) { - status = pthread_cond_signal (_cond) ; - assert (status == 0, "invariant") ; - status = pthread_mutex_unlock(_mutex); - assert (status == 0, "invariant") ; - } else { - status = pthread_mutex_unlock(_mutex); - assert (status == 0, "invariant") ; - status = pthread_cond_signal (_cond) ; - assert (status == 0, "invariant") ; - } - } else { - pthread_mutex_unlock(_mutex); - assert (status == 0, "invariant") ; - } -} - - -extern char** environ; - -#ifndef __NR_fork -#define __NR_fork IA32_ONLY(2) IA64_ONLY(not defined) AMD64_ONLY(57) -#endif - -#ifndef __NR_execve -#define __NR_execve IA32_ONLY(11) IA64_ONLY(1033) AMD64_ONLY(59) -#endif - -// Run the specified command in a separate process. Return its exit value, -// or -1 on failure (e.g. can't fork a new process). -// Unlike system(), this function can be called from signal handler. It -// doesn't block SIGINT et al. -int os::fork_and_exec(char* cmd) { - const char * argv[4] = {"sh", "-c", cmd, NULL}; - - // fork() in LinuxThreads/NPTL is not async-safe. It needs to run - // pthread_atfork handlers and reset pthread library. All we need is a - // separate process to execve. Make a direct syscall to fork process. - // On IA64 there's no fork syscall, we have to use fork() and hope for - // the best... - pid_t pid = NOT_IA64(syscall(__NR_fork);) - IA64_ONLY(fork();) - - if (pid < 0) { - // fork failed - return -1; - - } else if (pid == 0) { - // child process - - // execve() in LinuxThreads will call pthread_kill_other_threads_np() - // first to kill every thread on the thread list. Because this list is - // not reset by fork() (see notes above), execve() will instead kill - // every thread in the parent process. We know this is the only thread - // in the new process, so make a system call directly. - // IA64 should use normal execve() from glibc to match the glibc fork() - // above. - NOT_IA64(syscall(__NR_execve, "/bin/sh", argv, environ);) - IA64_ONLY(execve("/bin/sh", (char* const*)argv, environ);) - - // execve failed - _exit(-1); - - } else { - // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't - // care about the actual exit code, for now. - - int status; - - // Wait for the child process to exit. This returns immediately if - // the child has already exited. */ - while (waitpid(pid, &status, 0) < 0) { - switch (errno) { - case ECHILD: return 0; - case EINTR: break; - default: return -1; - } - } - - if (WIFEXITED(status)) { - // The child exited normally; get its exit code. - return WEXITSTATUS(status); - } else if (WIFSIGNALED(status)) { - // The child exited because of a signal - // The best value to return is 0x80 + signal number, - // because that is what all Unix shells do, and because - // it allows callers to distinguish between process exit and - // process death by signal. - return 0x80 + WTERMSIG(status); - } else { - // Unknown exit code; pass it through - return status; - } - } -} - -// is_headless_jre() -// -// Test for the existence of libmawt in motif21 or xawt directories -// in order to report if we are running in a headless jre -// -bool os::is_headless_jre() { - struct stat statbuf; - char buf[MAXPATHLEN]; - char libmawtpath[MAXPATHLEN]; - const char *xawtstr = "/xawt/libmawt.so"; - const char *motifstr = "/motif21/libmawt.so"; - char *p; - - // Get path to libjvm.so - os::jvm_path(buf, sizeof(buf)); - - // Get rid of libjvm.so - p = strrchr(buf, '/'); - if (p == NULL) return false; - else *p = '\0'; - - // Get rid of client or server - p = strrchr(buf, '/'); - if (p == NULL) return false; - else *p = '\0'; - - // check xawt/libmawt.so - strcpy(libmawtpath, buf); - strcat(libmawtpath, xawtstr); - if (::stat(libmawtpath, &statbuf) == 0) return false; - - // check motif21/libmawt.so - strcpy(libmawtpath, buf); - strcat(libmawtpath, motifstr); - if (::stat(libmawtpath, &statbuf) == 0) return false; - - return true; -} - - -#ifdef JAVASE_EMBEDDED -// -// A thread to watch the '/dev/mem_notify' device, which will tell us when the OS is running low on memory. -// -MemNotifyThread* MemNotifyThread::_memnotify_thread = NULL; - -// ctor -// -MemNotifyThread::MemNotifyThread(int fd): Thread() { - assert(memnotify_thread() == NULL, "we can only allocate one MemNotifyThread"); - _fd = fd; - - if (os::create_thread(this, os::os_thread)) { - _memnotify_thread = this; - os::set_priority(this, NearMaxPriority); - os::start_thread(this); - } -} - -// Where all the work gets done -// -void MemNotifyThread::run() { - assert(this == memnotify_thread(), "expected the singleton MemNotifyThread"); - - // Set up the select arguments - fd_set rfds; - if (_fd != -1) { - FD_ZERO(&rfds); - FD_SET(_fd, &rfds); - } - - // Now wait for the mem_notify device to wake up - while (1) { - // Wait for the mem_notify device to signal us.. - int rc = select(_fd+1, _fd != -1 ? &rfds : NULL, NULL, NULL, NULL); - if (rc == -1) { - perror("select!\n"); - break; - } else if (rc) { - //ssize_t free_before = os::available_memory(); - //tty->print ("Notified: Free: %dK \n",os::available_memory()/1024); - - // The kernel is telling us there is not much memory left... - // try to do something about that - - // If we are not already in a GC, try one. - if (!Universe::heap()->is_gc_active()) { - Universe::heap()->collect(GCCause::_allocation_failure); - - //ssize_t free_after = os::available_memory(); - //tty->print ("Post-Notify: Free: %dK\n",free_after/1024); - //tty->print ("GC freed: %dK\n", (free_after - free_before)/1024); - } - // We might want to do something like the following if we find the GC's are not helping... - // Universe::heap()->size_policy()->set_gc_time_limit_exceeded(true); - } - } -} - -// -// See if the /dev/mem_notify device exists, and if so, start a thread to monitor it. -// -void MemNotifyThread::start() { - int fd; - fd = open ("/dev/mem_notify", O_RDONLY, 0); - if (fd < 0) { - return; - } - - if (memnotify_thread() == NULL) { - new MemNotifyThread(fd); - } -} -#endif // JAVASE_EMBEDDED --- /dev/null Tue Sep 13 12:29:27 2011 +++ new/src/os/bsd/vm/os_bsd.cpp Tue Sep 13 12:29:50 2011 @@ -0,0 +1,5709 @@ +/* + * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +// no precompiled headers +#include "classfile/classLoader.hpp" +#include "classfile/systemDictionary.hpp" +#include "classfile/vmSymbols.hpp" +#include "code/icBuffer.hpp" +#include "code/vtableStubs.hpp" +#include "compiler/compileBroker.hpp" +#include "interpreter/interpreter.hpp" +#include "jvm_bsd.h" +#include "memory/allocation.inline.hpp" +#include "memory/filemap.hpp" +#include "mutex_bsd.inline.hpp" +#include "oops/oop.inline.hpp" +#include "os_share_bsd.hpp" +#include "prims/jniFastGetField.hpp" +#include "prims/jvm.h" +#include "prims/jvm_misc.hpp" +#include "runtime/arguments.hpp" +#include "runtime/extendedPC.hpp" +#include "runtime/globals.hpp" +#include "runtime/interfaceSupport.hpp" +#include "runtime/java.hpp" +#include "runtime/javaCalls.hpp" +#include "runtime/mutexLocker.hpp" +#include "runtime/objectMonitor.hpp" +#include "runtime/osThread.hpp" +#include "runtime/perfMemory.hpp" +#include "runtime/sharedRuntime.hpp" +#include "runtime/statSampler.hpp" +#include "runtime/stubRoutines.hpp" +#include "runtime/threadCritical.hpp" +#include "runtime/timer.hpp" +#include "services/attachListener.hpp" +#include "services/runtimeService.hpp" +#include "thread_bsd.inline.hpp" +#include "utilities/decoder.hpp" +#include "utilities/defaultStream.hpp" +#include "utilities/events.hpp" +#include "utilities/growableArray.hpp" +#include "utilities/vmError.hpp" +#ifdef TARGET_ARCH_x86 +# include "assembler_x86.inline.hpp" +# include "nativeInst_x86.hpp" +#endif +#ifdef TARGET_ARCH_sparc +# include "assembler_sparc.inline.hpp" +# include "nativeInst_sparc.hpp" +#endif +#ifdef TARGET_ARCH_zero +# include "assembler_zero.inline.hpp" +# include "nativeInst_zero.hpp" +#endif +#ifdef TARGET_ARCH_arm +# include "assembler_arm.inline.hpp" +# include "nativeInst_arm.hpp" +#endif +#ifdef TARGET_ARCH_ppc +# include "assembler_ppc.inline.hpp" +# include "nativeInst_ppc.hpp" +#endif +#ifdef COMPILER1 +#include "c1/c1_Runtime1.hpp" +#endif +#ifdef COMPILER2 +#include "opto/runtime.hpp" +#endif + +// put OS-includes here +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +# include +#ifdef _ALLBSD_SOURCE +# include +# include +#else +# include +# include +# include +#endif +# include +# include +#ifndef __APPLE__ +# include +#endif +# include +# include +# include + +#if defined(__FreeBSD__) || defined(__NetBSD__) +# include +#endif + +#ifdef __APPLE__ +#include // semaphore_* API +#include +#endif + +#ifndef MAP_ANONYMOUS +#define MAP_ANONYMOUS MAP_ANON +#endif + +#define MAX_PATH (2 * K) + +// for timer info max values which include all bits +#define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) +#define SEC_IN_NANOSECS 1000000000LL + +#define LARGEPAGES_BIT (1 << 6) +//////////////////////////////////////////////////////////////////////////////// +// global variables +julong os::Bsd::_physical_memory = 0; + +#ifndef _ALLBSD_SOURCE +address os::Bsd::_initial_thread_stack_bottom = NULL; +uintptr_t os::Bsd::_initial_thread_stack_size = 0; +#endif + +int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL; +#ifndef _ALLBSD_SOURCE +int (*os::Bsd::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL; +Mutex* os::Bsd::_createThread_lock = NULL; +#endif +pthread_t os::Bsd::_main_thread; +int os::Bsd::_page_size = -1; +#ifndef _ALLBSD_SOURCE +bool os::Bsd::_is_floating_stack = false; +bool os::Bsd::_is_NPTL = false; +bool os::Bsd::_supports_fast_thread_cpu_time = false; +const char * os::Bsd::_glibc_version = NULL; +const char * os::Bsd::_libpthread_version = NULL; +#endif + +static jlong initial_time_count=0; + +static int clock_tics_per_sec = 100; + +// For diagnostics to print a message once. see run_periodic_checks +static sigset_t check_signal_done; +static bool check_signals = true;; + +static pid_t _initial_pid = 0; + +/* Signal number used to suspend/resume a thread */ + +/* do not use any signal number less than SIGSEGV, see 4355769 */ +static int SR_signum = SIGUSR2; +sigset_t SR_sigset; + + +//////////////////////////////////////////////////////////////////////////////// +// utility functions + +static int SR_initialize(); +static int SR_finalize(); + +julong os::available_memory() { + return Bsd::available_memory(); +} + +julong os::Bsd::available_memory() { +#ifdef _ALLBSD_SOURCE + // XXXBSD: this is just a stopgap implementation + return physical_memory() >> 2; +#else + // values in struct sysinfo are "unsigned long" + struct sysinfo si; + sysinfo(&si); + + return (julong)si.freeram * si.mem_unit; +#endif +} + +julong os::physical_memory() { + return Bsd::physical_memory(); +} + +julong os::allocatable_physical_memory(julong size) { +#ifdef _LP64 + return size; +#else + julong result = MIN2(size, (julong)3800*M); + if (!is_allocatable(result)) { + // See comments under solaris for alignment considerations + julong reasonable_size = (julong)2*G - 2 * os::vm_page_size(); + result = MIN2(size, reasonable_size); + } + return result; +#endif // _LP64 +} + +//////////////////////////////////////////////////////////////////////////////// +// environment support + +bool os::getenv(const char* name, char* buf, int len) { + const char* val = ::getenv(name); + if (val != NULL && strlen(val) < (size_t)len) { + strcpy(buf, val); + return true; + } + if (len > 0) buf[0] = 0; // return a null string + return false; +} + + +// Return true if user is running as root. + +bool os::have_special_privileges() { + static bool init = false; + static bool privileges = false; + if (!init) { + privileges = (getuid() != geteuid()) || (getgid() != getegid()); + init = true; + } + return privileges; +} + + +#ifndef _ALLBSD_SOURCE +#ifndef SYS_gettid +// i386: 224, ia64: 1105, amd64: 186, sparc 143 +#ifdef __ia64__ +#define SYS_gettid 1105 +#elif __i386__ +#define SYS_gettid 224 +#elif __amd64__ +#define SYS_gettid 186 +#elif __sparc__ +#define SYS_gettid 143 +#else +#error define gettid for the arch +#endif +#endif +#endif + +// Cpu architecture string +#if defined(ZERO) +static char cpu_arch[] = ZERO_LIBARCH; +#elif defined(IA64) +static char cpu_arch[] = "ia64"; +#elif defined(IA32) +static char cpu_arch[] = "i386"; +#elif defined(AMD64) +static char cpu_arch[] = "amd64"; +#elif defined(ARM) +static char cpu_arch[] = "arm"; +#elif defined(PPC) +static char cpu_arch[] = "ppc"; +#elif defined(SPARC) +# ifdef _LP64 +static char cpu_arch[] = "sparcv9"; +# else +static char cpu_arch[] = "sparc"; +# endif +#else +#error Add appropriate cpu_arch setting +#endif + + +#ifndef _ALLBSD_SOURCE +// pid_t gettid() +// +// Returns the kernel thread id of the currently running thread. Kernel +// thread id is used to access /proc. +// +// (Note that getpid() on BsdThreads returns kernel thread id too; but +// on NPTL, it returns the same pid for all threads, as required by POSIX.) +// +pid_t os::Bsd::gettid() { + int rslt = syscall(SYS_gettid); + if (rslt == -1) { + // old kernel, no NPTL support + return getpid(); + } else { + return (pid_t)rslt; + } +} + +// Most versions of bsd have a bug where the number of processors are +// determined by looking at the /proc file system. In a chroot environment, +// the system call returns 1. This causes the VM to act as if it is +// a single processor and elide locking (see is_MP() call). +static bool unsafe_chroot_detected = false; +static const char *unstable_chroot_error = "/proc file system not found.\n" + "Java may be unstable running multithreaded in a chroot " + "environment on Bsd when /proc filesystem is not mounted."; +#endif + +#ifdef _ALLBSD_SOURCE +void os::Bsd::initialize_system_info() { + int mib[2]; + size_t len; + int cpu_val; + u_long mem_val; + + /* get processors count via hw.ncpus sysctl */ + mib[0] = CTL_HW; + mib[1] = HW_NCPU; + len = sizeof(cpu_val); + if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) { + set_processor_count(cpu_val); + } + else { + set_processor_count(1); // fallback + } + + /* get physical memory via hw.usermem sysctl (hw.usermem is used + * instead of hw.physmem because we need size of allocatable memory + */ + mib[0] = CTL_HW; + mib[1] = HW_USERMEM; + len = sizeof(mem_val); + if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) + _physical_memory = mem_val; + else + _physical_memory = 256*1024*1024; // fallback (XXXBSD?) + +#ifdef __OpenBSD__ + { + // limit _physical_memory memory view on OpenBSD since + // datasize rlimit restricts us anyway. + struct rlimit limits; + getrlimit(RLIMIT_DATA, &limits); + _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur); + } +#endif +} +#else +void os::Bsd::initialize_system_info() { + set_processor_count(sysconf(_SC_NPROCESSORS_CONF)); + if (processor_count() == 1) { + pid_t pid = os::Bsd::gettid(); + char fname[32]; + jio_snprintf(fname, sizeof(fname), "/proc/%d", pid); + FILE *fp = fopen(fname, "r"); + if (fp == NULL) { + unsafe_chroot_detected = true; + } else { + fclose(fp); + } + } + _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE); + assert(processor_count() > 0, "bsd error"); +} +#endif + +void os::init_system_properties_values() { +// char arch[12]; +// sysinfo(SI_ARCHITECTURE, arch, sizeof(arch)); + + // The next steps are taken in the product version: + // + // Obtain the JAVA_HOME value from the location of libjvm[_g].so. + // This library should be located at: + // /jre/lib//{client|server}/libjvm[_g].so. + // + // If "/jre/lib/" appears at the right place in the path, then we + // assume libjvm[_g].so is installed in a JDK and we use this path. + // + // Otherwise exit with message: "Could not create the Java virtual machine." + // + // The following extra steps are taken in the debugging version: + // + // If "/jre/lib/" does NOT appear at the right place in the path + // instead of exit check for $JAVA_HOME environment variable. + // + // If it is defined and we are able to locate $JAVA_HOME/jre/lib/, + // then we append a fake suffix "hotspot/libjvm[_g].so" to this path so + // it looks like libjvm[_g].so is installed there + // /jre/lib//hotspot/libjvm[_g].so. + // + // Otherwise exit. + // + // Important note: if the location of libjvm.so changes this + // code needs to be changed accordingly. + + // The next few definitions allow the code to be verbatim: +#define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n)) +#define getenv(n) ::getenv(n) + +/* + * See ld(1): + * The linker uses the following search paths to locate required + * shared libraries: + * 1: ... + * ... + * 7: The default directories, normally /lib and /usr/lib. + */ +#ifndef DEFAULT_LIBPATH +#define DEFAULT_LIBPATH "/lib:/usr/lib" +#endif + +#define EXTENSIONS_DIR "/lib/ext" +#define ENDORSED_DIR "/lib/endorsed" +#define REG_DIR "/usr/java/packages" + + { + /* sysclasspath, java_home, dll_dir */ + { + char *home_path; + char *dll_path; + char *pslash; + char buf[MAXPATHLEN]; + os::jvm_path(buf, sizeof(buf)); + + // Found the full path to libjvm.so. + // Now cut the path to /jre if we can. + *(strrchr(buf, '/')) = '\0'; /* get rid of /libjvm.so */ + pslash = strrchr(buf, '/'); + if (pslash != NULL) + *pslash = '\0'; /* get rid of /{client|server|hotspot} */ + dll_path = malloc(strlen(buf) + 1); + if (dll_path == NULL) + return; + strcpy(dll_path, buf); + Arguments::set_dll_dir(dll_path); + + if (pslash != NULL) { + pslash = strrchr(buf, '/'); + if (pslash != NULL) { + *pslash = '\0'; /* get rid of / */ + pslash = strrchr(buf, '/'); + if (pslash != NULL) + *pslash = '\0'; /* get rid of /lib */ + } + } + + home_path = malloc(strlen(buf) + 1); + if (home_path == NULL) + return; + strcpy(home_path, buf); + Arguments::set_java_home(home_path); + + if (!set_boot_path('/', ':')) + return; + } + + /* + * Where to look for native libraries + * + * Note: Due to a legacy implementation, most of the library path + * is set in the launcher. This was to accomodate linking restrictions + * on legacy Bsd implementations (which are no longer supported). + * Eventually, all the library path setting will be done here. + * + * However, to prevent the proliferation of improperly built native + * libraries, the new path component /usr/java/packages is added here. + * Eventually, all the library path setting will be done here. + */ + { + char *ld_library_path; + + /* + * Construct the invariant part of ld_library_path. Note that the + * space for the colon and the trailing null are provided by the + * nulls included by the sizeof operator (so actually we allocate + * a byte more than necessary). + */ + ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") + + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH)); + sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch); + + /* + * Get the user setting of LD_LIBRARY_PATH, and prepended it. It + * should always exist (until the legacy problem cited above is + * addressed). + */ +#ifdef __APPLE__ + char *v = getenv("DYLD_LIBRARY_PATH"); +#else + char *v = getenv("LD_LIBRARY_PATH"); +#endif + if (v != NULL) { + char *t = ld_library_path; + /* That's +1 for the colon and +1 for the trailing '\0' */ + ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1); + sprintf(ld_library_path, "%s:%s", v, t); + } + Arguments::set_library_path(ld_library_path); + } + + /* + * Extensions directories. + * + * Note that the space for the colon and the trailing null are provided + * by the nulls included by the sizeof operator (so actually one byte more + * than necessary is allocated). + */ + { + char *buf = malloc(strlen(Arguments::get_java_home()) + + sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR)); + sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR, + Arguments::get_java_home()); + Arguments::set_ext_dirs(buf); + } + + /* Endorsed standards default directory. */ + { + char * buf; + buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR)); + sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home()); + Arguments::set_endorsed_dirs(buf); + } + } + +#undef malloc +#undef getenv +#undef EXTENSIONS_DIR +#undef ENDORSED_DIR + + // Done + return; +} + +//////////////////////////////////////////////////////////////////////////////// +// breakpoint support + +void os::breakpoint() { + BREAKPOINT; +} + +extern "C" void breakpoint() { + // use debugger to set breakpoint here +} + +//////////////////////////////////////////////////////////////////////////////// +// signal support + +debug_only(static bool signal_sets_initialized = false); +static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; + +bool os::Bsd::is_sig_ignored(int sig) { + struct sigaction oact; + sigaction(sig, (struct sigaction*)NULL, &oact); + void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) + : CAST_FROM_FN_PTR(void*, oact.sa_handler); + if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) + return true; + else + return false; +} + +void os::Bsd::signal_sets_init() { + // Should also have an assertion stating we are still single-threaded. + assert(!signal_sets_initialized, "Already initialized"); + // Fill in signals that are necessarily unblocked for all threads in + // the VM. Currently, we unblock the following signals: + // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden + // by -Xrs (=ReduceSignalUsage)); + // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all + // other threads. The "ReduceSignalUsage" boolean tells us not to alter + // the dispositions or masks wrt these signals. + // Programs embedding the VM that want to use the above signals for their + // own purposes must, at this time, use the "-Xrs" option to prevent + // interference with shutdown hooks and BREAK_SIGNAL thread dumping. + // (See bug 4345157, and other related bugs). + // In reality, though, unblocking these signals is really a nop, since + // these signals are not blocked by default. + sigemptyset(&unblocked_sigs); + sigemptyset(&allowdebug_blocked_sigs); + sigaddset(&unblocked_sigs, SIGILL); + sigaddset(&unblocked_sigs, SIGSEGV); + sigaddset(&unblocked_sigs, SIGBUS); + sigaddset(&unblocked_sigs, SIGFPE); + sigaddset(&unblocked_sigs, SR_signum); + + if (!ReduceSignalUsage) { + if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) { + sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); + sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); + } + if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) { + sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); + sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); + } + if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) { + sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); + sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); + } + } + // Fill in signals that are blocked by all but the VM thread. + sigemptyset(&vm_sigs); + if (!ReduceSignalUsage) + sigaddset(&vm_sigs, BREAK_SIGNAL); + debug_only(signal_sets_initialized = true); + +} + +// These are signals that are unblocked while a thread is running Java. +// (For some reason, they get blocked by default.) +sigset_t* os::Bsd::unblocked_signals() { + assert(signal_sets_initialized, "Not initialized"); + return &unblocked_sigs; +} + +// These are the signals that are blocked while a (non-VM) thread is +// running Java. Only the VM thread handles these signals. +sigset_t* os::Bsd::vm_signals() { + assert(signal_sets_initialized, "Not initialized"); + return &vm_sigs; +} + +// These are signals that are blocked during cond_wait to allow debugger in +sigset_t* os::Bsd::allowdebug_blocked_signals() { + assert(signal_sets_initialized, "Not initialized"); + return &allowdebug_blocked_sigs; +} + +void os::Bsd::hotspot_sigmask(Thread* thread) { + + //Save caller's signal mask before setting VM signal mask + sigset_t caller_sigmask; + pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); + + OSThread* osthread = thread->osthread(); + osthread->set_caller_sigmask(caller_sigmask); + + pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL); + + if (!ReduceSignalUsage) { + if (thread->is_VM_thread()) { + // Only the VM thread handles BREAK_SIGNAL ... + pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); + } else { + // ... all other threads block BREAK_SIGNAL + pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); + } + } +} + +#ifndef _ALLBSD_SOURCE +////////////////////////////////////////////////////////////////////////////// +// detecting pthread library + +void os::Bsd::libpthread_init() { + // Save glibc and pthread version strings. Note that _CS_GNU_LIBC_VERSION + // and _CS_GNU_LIBPTHREAD_VERSION are supported in glibc >= 2.3.2. Use a + // generic name for earlier versions. + // Define macros here so we can build HotSpot on old systems. +# ifndef _CS_GNU_LIBC_VERSION +# define _CS_GNU_LIBC_VERSION 2 +# endif +# ifndef _CS_GNU_LIBPTHREAD_VERSION +# define _CS_GNU_LIBPTHREAD_VERSION 3 +# endif + + size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0); + if (n > 0) { + char *str = (char *)malloc(n); + confstr(_CS_GNU_LIBC_VERSION, str, n); + os::Bsd::set_glibc_version(str); + } else { + // _CS_GNU_LIBC_VERSION is not supported, try gnu_get_libc_version() + static char _gnu_libc_version[32]; + jio_snprintf(_gnu_libc_version, sizeof(_gnu_libc_version), + "glibc %s %s", gnu_get_libc_version(), gnu_get_libc_release()); + os::Bsd::set_glibc_version(_gnu_libc_version); + } + + n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0); + if (n > 0) { + char *str = (char *)malloc(n); + confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n); + // Vanilla RH-9 (glibc 2.3.2) has a bug that confstr() always tells + // us "NPTL-0.29" even we are running with BsdThreads. Check if this + // is the case. BsdThreads has a hard limit on max number of threads. + // So sysconf(_SC_THREAD_THREADS_MAX) will return a positive value. + // On the other hand, NPTL does not have such a limit, sysconf() + // will return -1 and errno is not changed. Check if it is really NPTL. + if (strcmp(os::Bsd::glibc_version(), "glibc 2.3.2") == 0 && + strstr(str, "NPTL") && + sysconf(_SC_THREAD_THREADS_MAX) > 0) { + free(str); + os::Bsd::set_libpthread_version("bsdthreads"); + } else { + os::Bsd::set_libpthread_version(str); + } + } else { + // glibc before 2.3.2 only has BsdThreads. + os::Bsd::set_libpthread_version("bsdthreads"); + } + + if (strstr(libpthread_version(), "NPTL")) { + os::Bsd::set_is_NPTL(); + } else { + os::Bsd::set_is_BsdThreads(); + } + + // BsdThreads have two flavors: floating-stack mode, which allows variable + // stack size; and fixed-stack mode. NPTL is always floating-stack. + if (os::Bsd::is_NPTL() || os::Bsd::supports_variable_stack_size()) { + os::Bsd::set_is_floating_stack(); + } +} + +///////////////////////////////////////////////////////////////////////////// +// thread stack + +// Force Bsd kernel to expand current thread stack. If "bottom" is close +// to the stack guard, caller should block all signals. +// +// MAP_GROWSDOWN: +// A special mmap() flag that is used to implement thread stacks. It tells +// kernel that the memory region should extend downwards when needed. This +// allows early versions of BsdThreads to only mmap the first few pages +// when creating a new thread. Bsd kernel will automatically expand thread +// stack as needed (on page faults). +// +// However, because the memory region of a MAP_GROWSDOWN stack can grow on +// demand, if a page fault happens outside an already mapped MAP_GROWSDOWN +// region, it's hard to tell if the fault is due to a legitimate stack +// access or because of reading/writing non-exist memory (e.g. buffer +// overrun). As a rule, if the fault happens below current stack pointer, +// Bsd kernel does not expand stack, instead a SIGSEGV is sent to the +// application (see Bsd kernel fault.c). +// +// This Bsd feature can cause SIGSEGV when VM bangs thread stack for +// stack overflow detection. +// +// Newer version of BsdThreads (since glibc-2.2, or, RH-7.x) and NPTL do +// not use this flag. However, the stack of initial thread is not created +// by pthread, it is still MAP_GROWSDOWN. Also it's possible (though +// unlikely) that user code can create a thread with MAP_GROWSDOWN stack +// and then attach the thread to JVM. +// +// To get around the problem and allow stack banging on Bsd, we need to +// manually expand thread stack after receiving the SIGSEGV. +// +// There are two ways to expand thread stack to address "bottom", we used +// both of them in JVM before 1.5: +// 1. adjust stack pointer first so that it is below "bottom", and then +// touch "bottom" +// 2. mmap() the page in question +// +// Now alternate signal stack is gone, it's harder to use 2. For instance, +// if current sp is already near the lower end of page 101, and we need to +// call mmap() to map page 100, it is possible that part of the mmap() frame +// will be placed in page 100. When page 100 is mapped, it is zero-filled. +// That will destroy the mmap() frame and cause VM to crash. +// +// The following code works by adjusting sp first, then accessing the "bottom" +// page to force a page fault. Bsd kernel will then automatically expand the +// stack mapping. +// +// _expand_stack_to() assumes its frame size is less than page size, which +// should always be true if the function is not inlined. + +#if __GNUC__ < 3 // gcc 2.x does not support noinline attribute +#define NOINLINE +#else +#define NOINLINE __attribute__ ((noinline)) +#endif + +static void _expand_stack_to(address bottom) NOINLINE; + +static void _expand_stack_to(address bottom) { + address sp; + size_t size; + volatile char *p; + + // Adjust bottom to point to the largest address within the same page, it + // gives us a one-page buffer if alloca() allocates slightly more memory. + bottom = (address)align_size_down((uintptr_t)bottom, os::Bsd::page_size()); + bottom += os::Bsd::page_size() - 1; + + // sp might be slightly above current stack pointer; if that's the case, we + // will alloca() a little more space than necessary, which is OK. Don't use + // os::current_stack_pointer(), as its result can be slightly below current + // stack pointer, causing us to not alloca enough to reach "bottom". + sp = (address)&sp; + + if (sp > bottom) { + size = sp - bottom; + p = (volatile char *)alloca(size); + assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?"); + p[0] = '\0'; + } +} + +bool os::Bsd::manually_expand_stack(JavaThread * t, address addr) { + assert(t!=NULL, "just checking"); + assert(t->osthread()->expanding_stack(), "expand should be set"); + assert(t->stack_base() != NULL, "stack_base was not initialized"); + + if (addr < t->stack_base() && addr >= t->stack_yellow_zone_base()) { + sigset_t mask_all, old_sigset; + sigfillset(&mask_all); + pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset); + _expand_stack_to(addr); + pthread_sigmask(SIG_SETMASK, &old_sigset, NULL); + return true; + } + return false; +} +#endif + +////////////////////////////////////////////////////////////////////////////// +// create new thread + +static address highest_vm_reserved_address(); + +// check if it's safe to start a new thread +static bool _thread_safety_check(Thread* thread) { +#ifdef _ALLBSD_SOURCE + return true; +#else + if (os::Bsd::is_BsdThreads() && !os::Bsd::is_floating_stack()) { + // Fixed stack BsdThreads (SuSE Bsd/x86, and some versions of Redhat) + // Heap is mmap'ed at lower end of memory space. Thread stacks are + // allocated (MAP_FIXED) from high address space. Every thread stack + // occupies a fixed size slot (usually 2Mbytes, but user can change + // it to other values if they rebuild BsdThreads). + // + // Problem with MAP_FIXED is that mmap() can still succeed even part of + // the memory region has already been mmap'ed. That means if we have too + // many threads and/or very large heap, eventually thread stack will + // collide with heap. + // + // Here we try to prevent heap/stack collision by comparing current + // stack bottom with the highest address that has been mmap'ed by JVM + // plus a safety margin for memory maps created by native code. + // + // This feature can be disabled by setting ThreadSafetyMargin to 0 + // + if (ThreadSafetyMargin > 0) { + address stack_bottom = os::current_stack_base() - os::current_stack_size(); + + // not safe if our stack extends below the safety margin + return stack_bottom - ThreadSafetyMargin >= highest_vm_reserved_address(); + } else { + return true; + } + } else { + // Floating stack BsdThreads or NPTL: + // Unlike fixed stack BsdThreads, thread stacks are not MAP_FIXED. When + // there's not enough space left, pthread_create() will fail. If we come + // here, that means enough space has been reserved for stack. + return true; + } +#endif +} + +// Thread start routine for all newly created threads +static void *java_start(Thread *thread) { + // Try to randomize the cache line index of hot stack frames. + // This helps when threads of the same stack traces evict each other's + // cache lines. The threads can be either from the same JVM instance, or + // from different JVM instances. The benefit is especially true for + // processors with hyperthreading technology. + static int counter = 0; + int pid = os::current_process_id(); + alloca(((pid ^ counter++) & 7) * 128); + + ThreadLocalStorage::set_thread(thread); + + OSThread* osthread = thread->osthread(); + Monitor* sync = osthread->startThread_lock(); + + // non floating stack BsdThreads needs extra check, see above + if (!_thread_safety_check(thread)) { + // notify parent thread + MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); + osthread->set_state(ZOMBIE); + sync->notify_all(); + return NULL; + } + +#ifdef _ALLBSD_SOURCE + // thread_id is pthread_id on BSD + osthread->set_thread_id(::pthread_self()); +#else + // thread_id is kernel thread id (similar to Solaris LWP id) + osthread->set_thread_id(os::Bsd::gettid()); + + if (UseNUMA) { + int lgrp_id = os::numa_get_group_id(); + if (lgrp_id != -1) { + thread->set_lgrp_id(lgrp_id); + } + } +#endif + // initialize signal mask for this thread + os::Bsd::hotspot_sigmask(thread); + + // initialize floating point control register + os::Bsd::init_thread_fpu_state(); + + // handshaking with parent thread + { + MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); + + // notify parent thread + osthread->set_state(INITIALIZED); + sync->notify_all(); + + // wait until os::start_thread() + while (osthread->get_state() == INITIALIZED) { + sync->wait(Mutex::_no_safepoint_check_flag); + } + } + + // call one more level start routine + thread->run(); + + return 0; +} + +bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { + assert(thread->osthread() == NULL, "caller responsible"); + + // Allocate the OSThread object + OSThread* osthread = new OSThread(NULL, NULL); + if (osthread == NULL) { + return false; + } + + // set the correct thread state + osthread->set_thread_type(thr_type); + + // Initial state is ALLOCATED but not INITIALIZED + osthread->set_state(ALLOCATED); + + thread->set_osthread(osthread); + + // init thread attributes + pthread_attr_t attr; + pthread_attr_init(&attr); + pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); + + // stack size + if (os::Bsd::supports_variable_stack_size()) { + // calculate stack size if it's not specified by caller + if (stack_size == 0) { + stack_size = os::Bsd::default_stack_size(thr_type); + + switch (thr_type) { + case os::java_thread: + // Java threads use ThreadStackSize which default value can be + // changed with the flag -Xss + assert (JavaThread::stack_size_at_create() > 0, "this should be set"); + stack_size = JavaThread::stack_size_at_create(); + break; + case os::compiler_thread: + if (CompilerThreadStackSize > 0) { + stack_size = (size_t)(CompilerThreadStackSize * K); + break; + } // else fall through: + // use VMThreadStackSize if CompilerThreadStackSize is not defined + case os::vm_thread: + case os::pgc_thread: + case os::cgc_thread: + case os::watcher_thread: + if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); + break; + } + } + + stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed); + pthread_attr_setstacksize(&attr, stack_size); + } else { + // let pthread_create() pick the default value. + } + +#ifndef _ALLBSD_SOURCE + // glibc guard page + pthread_attr_setguardsize(&attr, os::Bsd::default_guard_size(thr_type)); +#endif + + ThreadState state; + + { + +#ifndef _ALLBSD_SOURCE + // Serialize thread creation if we are running with fixed stack BsdThreads + bool lock = os::Bsd::is_BsdThreads() && !os::Bsd::is_floating_stack(); + if (lock) { + os::Bsd::createThread_lock()->lock_without_safepoint_check(); + } +#endif + + pthread_t tid; + int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); + + pthread_attr_destroy(&attr); + + if (ret != 0) { + if (PrintMiscellaneous && (Verbose || WizardMode)) { + perror("pthread_create()"); + } + // Need to clean up stuff we've allocated so far + thread->set_osthread(NULL); + delete osthread; +#ifndef _ALLBSD_SOURCE + if (lock) os::Bsd::createThread_lock()->unlock(); +#endif + return false; + } + + // Store pthread info into the OSThread + osthread->set_pthread_id(tid); + + // Wait until child thread is either initialized or aborted + { + Monitor* sync_with_child = osthread->startThread_lock(); + MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); + while ((state = osthread->get_state()) == ALLOCATED) { + sync_with_child->wait(Mutex::_no_safepoint_check_flag); + } + } + +#ifndef _ALLBSD_SOURCE + if (lock) { + os::Bsd::createThread_lock()->unlock(); + } +#endif + } + + // Aborted due to thread limit being reached + if (state == ZOMBIE) { + thread->set_osthread(NULL); + delete osthread; + return false; + } + + // The thread is returned suspended (in state INITIALIZED), + // and is started higher up in the call chain + assert(state == INITIALIZED, "race condition"); + return true; +} + +///////////////////////////////////////////////////////////////////////////// +// attach existing thread + +// bootstrap the main thread +bool os::create_main_thread(JavaThread* thread) { + assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread"); + return create_attached_thread(thread); +} + +bool os::create_attached_thread(JavaThread* thread) { +#ifdef ASSERT + thread->verify_not_published(); +#endif + + // Allocate the OSThread object + OSThread* osthread = new OSThread(NULL, NULL); + + if (osthread == NULL) { + return false; + } + + // Store pthread info into the OSThread +#ifdef _ALLBSD_SOURCE + osthread->set_thread_id(::pthread_self()); +#else + osthread->set_thread_id(os::Bsd::gettid()); +#endif + osthread->set_pthread_id(::pthread_self()); + + // initialize floating point control register + os::Bsd::init_thread_fpu_state(); + + // Initial thread state is RUNNABLE + osthread->set_state(RUNNABLE); + + thread->set_osthread(osthread); + +#ifndef _ALLBSD_SOURCE + if (UseNUMA) { + int lgrp_id = os::numa_get_group_id(); + if (lgrp_id != -1) { + thread->set_lgrp_id(lgrp_id); + } + } + + if (os::Bsd::is_initial_thread()) { + // If current thread is initial thread, its stack is mapped on demand, + // see notes about MAP_GROWSDOWN. Here we try to force kernel to map + // the entire stack region to avoid SEGV in stack banging. + // It is also useful to get around the heap-stack-gap problem on SuSE + // kernel (see 4821821 for details). We first expand stack to the top + // of yellow zone, then enable stack yellow zone (order is significant, + // enabling yellow zone first will crash JVM on SuSE Bsd), so there + // is no gap between the last two virtual memory regions. + + JavaThread *jt = (JavaThread *)thread; + address addr = jt->stack_yellow_zone_base(); + assert(addr != NULL, "initialization problem?"); + assert(jt->stack_available(addr) > 0, "stack guard should not be enabled"); + + osthread->set_expanding_stack(); + os::Bsd::manually_expand_stack(jt, addr); + osthread->clear_expanding_stack(); + } +#endif + + // initialize signal mask for this thread + // and save the caller's signal mask + os::Bsd::hotspot_sigmask(thread); + + return true; +} + +void os::pd_start_thread(Thread* thread) { + OSThread * osthread = thread->osthread(); + assert(osthread->get_state() != INITIALIZED, "just checking"); + Monitor* sync_with_child = osthread->startThread_lock(); + MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); + sync_with_child->notify(); +} + +// Free Bsd resources related to the OSThread +void os::free_thread(OSThread* osthread) { + assert(osthread != NULL, "osthread not set"); + + if (Thread::current()->osthread() == osthread) { + // Restore caller's signal mask + sigset_t sigmask = osthread->caller_sigmask(); + pthread_sigmask(SIG_SETMASK, &sigmask, NULL); + } + + delete osthread; +} + +////////////////////////////////////////////////////////////////////////////// +// thread local storage + +int os::allocate_thread_local_storage() { + pthread_key_t key; + int rslt = pthread_key_create(&key, NULL); + assert(rslt == 0, "cannot allocate thread local storage"); + return (int)key; +} + +// Note: This is currently not used by VM, as we don't destroy TLS key +// on VM exit. +void os::free_thread_local_storage(int index) { + int rslt = pthread_key_delete((pthread_key_t)index); + assert(rslt == 0, "invalid index"); +} + +void os::thread_local_storage_at_put(int index, void* value) { + int rslt = pthread_setspecific((pthread_key_t)index, value); + assert(rslt == 0, "pthread_setspecific failed"); +} + +extern "C" Thread* get_thread() { + return ThreadLocalStorage::thread(); +} + +////////////////////////////////////////////////////////////////////////////// +// initial thread + +#ifndef _ALLBSD_SOURCE +// Check if current thread is the initial thread, similar to Solaris thr_main. +bool os::Bsd::is_initial_thread(void) { + char dummy; + // If called before init complete, thread stack bottom will be null. + // Can be called if fatal error occurs before initialization. + if (initial_thread_stack_bottom() == NULL) return false; + assert(initial_thread_stack_bottom() != NULL && + initial_thread_stack_size() != 0, + "os::init did not locate initial thread's stack region"); + if ((address)&dummy >= initial_thread_stack_bottom() && + (address)&dummy < initial_thread_stack_bottom() + initial_thread_stack_size()) + return true; + else return false; +} + +// Find the virtual memory area that contains addr +static bool find_vma(address addr, address* vma_low, address* vma_high) { + FILE *fp = fopen("/proc/self/maps", "r"); + if (fp) { + address low, high; + while (!feof(fp)) { + if (fscanf(fp, "%p-%p", &low, &high) == 2) { + if (low <= addr && addr < high) { + if (vma_low) *vma_low = low; + if (vma_high) *vma_high = high; + fclose (fp); + return true; + } + } + for (;;) { + int ch = fgetc(fp); + if (ch == EOF || ch == (int)'\n') break; + } + } + fclose(fp); + } + return false; +} + +// Locate initial thread stack. This special handling of initial thread stack +// is needed because pthread_getattr_np() on most (all?) Bsd distros returns +// bogus value for initial thread. +void os::Bsd::capture_initial_stack(size_t max_size) { + // stack size is the easy part, get it from RLIMIT_STACK + size_t stack_size; + struct rlimit rlim; + getrlimit(RLIMIT_STACK, &rlim); + stack_size = rlim.rlim_cur; + + // 6308388: a bug in ld.so will relocate its own .data section to the + // lower end of primordial stack; reduce ulimit -s value a little bit + // so we won't install guard page on ld.so's data section. + stack_size -= 2 * page_size(); + + // 4441425: avoid crash with "unlimited" stack size on SuSE 7.1 or Redhat + // 7.1, in both cases we will get 2G in return value. + // 4466587: glibc 2.2.x compiled w/o "--enable-kernel=2.4.0" (RH 7.0, + // SuSE 7.2, Debian) can not handle alternate signal stack correctly + // for initial thread if its stack size exceeds 6M. Cap it at 2M, + // in case other parts in glibc still assumes 2M max stack size. + // FIXME: alt signal stack is gone, maybe we can relax this constraint? +#ifndef IA64 + if (stack_size > 2 * K * K) stack_size = 2 * K * K; +#else + // Problem still exists RH7.2 (IA64 anyway) but 2MB is a little small + if (stack_size > 4 * K * K) stack_size = 4 * K * K; +#endif + + // Try to figure out where the stack base (top) is. This is harder. + // + // When an application is started, glibc saves the initial stack pointer in + // a global variable "__libc_stack_end", which is then used by system + // libraries. __libc_stack_end should be pretty close to stack top. The + // variable is available since the very early days. However, because it is + // a private interface, it could disappear in the future. + // + // Bsd kernel saves start_stack information in /proc//stat. Similar + // to __libc_stack_end, it is very close to stack top, but isn't the real + // stack top. Note that /proc may not exist if VM is running as a chroot + // program, so reading /proc//stat could fail. Also the contents of + // /proc//stat could change in the future (though unlikely). + // + // We try __libc_stack_end first. If that doesn't work, look for + // /proc//stat. If neither of them works, we use current stack pointer + // as a hint, which should work well in most cases. + + uintptr_t stack_start; + + // try __libc_stack_end first + uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end"); + if (p && *p) { + stack_start = *p; + } else { + // see if we can get the start_stack field from /proc/self/stat + FILE *fp; + int pid; + char state; + int ppid; + int pgrp; + int session; + int nr; + int tpgrp; + unsigned long flags; + unsigned long minflt; + unsigned long cminflt; + unsigned long majflt; + unsigned long cmajflt; + unsigned long utime; + unsigned long stime; + long cutime; + long cstime; + long prio; + long nice; + long junk; + long it_real; + uintptr_t start; + uintptr_t vsize; + intptr_t rss; + uintptr_t rsslim; + uintptr_t scodes; + uintptr_t ecode; + int i; + + // Figure what the primordial thread stack base is. Code is inspired + // by email from Hans Boehm. /proc/self/stat begins with current pid, + // followed by command name surrounded by parentheses, state, etc. + char stat[2048]; + int statlen; + + fp = fopen("/proc/self/stat", "r"); + if (fp) { + statlen = fread(stat, 1, 2047, fp); + stat[statlen] = '\0'; + fclose(fp); + + // Skip pid and the command string. Note that we could be dealing with + // weird command names, e.g. user could decide to rename java launcher + // to "java 1.4.2 :)", then the stat file would look like + // 1234 (java 1.4.2 :)) R ... ... + // We don't really need to know the command string, just find the last + // occurrence of ")" and then start parsing from there. See bug 4726580. + char * s = strrchr(stat, ')'); + + i = 0; + if (s) { + // Skip blank chars + do s++; while (isspace(*s)); + +#define _UFM UINTX_FORMAT +#define _DFM INTX_FORMAT + + /* 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 */ + /* 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 */ + i = sscanf(s, "%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld " _UFM _UFM _DFM _UFM _UFM _UFM _UFM, + &state, /* 3 %c */ + &ppid, /* 4 %d */ + &pgrp, /* 5 %d */ + &session, /* 6 %d */ + &nr, /* 7 %d */ + &tpgrp, /* 8 %d */ + &flags, /* 9 %lu */ + &minflt, /* 10 %lu */ + &cminflt, /* 11 %lu */ + &majflt, /* 12 %lu */ + &cmajflt, /* 13 %lu */ + &utime, /* 14 %lu */ + &stime, /* 15 %lu */ + &cutime, /* 16 %ld */ + &cstime, /* 17 %ld */ + &prio, /* 18 %ld */ + &nice, /* 19 %ld */ + &junk, /* 20 %ld */ + &it_real, /* 21 %ld */ + &start, /* 22 UINTX_FORMAT */ + &vsize, /* 23 UINTX_FORMAT */ + &rss, /* 24 INTX_FORMAT */ + &rsslim, /* 25 UINTX_FORMAT */ + &scodes, /* 26 UINTX_FORMAT */ + &ecode, /* 27 UINTX_FORMAT */ + &stack_start); /* 28 UINTX_FORMAT */ + } + +#undef _UFM +#undef _DFM + + if (i != 28 - 2) { + assert(false, "Bad conversion from /proc/self/stat"); + // product mode - assume we are the initial thread, good luck in the + // embedded case. + warning("Can't detect initial thread stack location - bad conversion"); + stack_start = (uintptr_t) &rlim; + } + } else { + // For some reason we can't open /proc/self/stat (for example, running on + // FreeBSD with a Bsd emulator, or inside chroot), this should work for + // most cases, so don't abort: + warning("Can't detect initial thread stack location - no /proc/self/stat"); + stack_start = (uintptr_t) &rlim; + } + } + + // Now we have a pointer (stack_start) very close to the stack top, the + // next thing to do is to figure out the exact location of stack top. We + // can find out the virtual memory area that contains stack_start by + // reading /proc/self/maps, it should be the last vma in /proc/self/maps, + // and its upper limit is the real stack top. (again, this would fail if + // running inside chroot, because /proc may not exist.) + + uintptr_t stack_top; + address low, high; + if (find_vma((address)stack_start, &low, &high)) { + // success, "high" is the true stack top. (ignore "low", because initial + // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.) + stack_top = (uintptr_t)high; + } else { + // failed, likely because /proc/self/maps does not exist + warning("Can't detect initial thread stack location - find_vma failed"); + // best effort: stack_start is normally within a few pages below the real + // stack top, use it as stack top, and reduce stack size so we won't put + // guard page outside stack. + stack_top = stack_start; + stack_size -= 16 * page_size(); + } + + // stack_top could be partially down the page so align it + stack_top = align_size_up(stack_top, page_size()); + + if (max_size && stack_size > max_size) { + _initial_thread_stack_size = max_size; + } else { + _initial_thread_stack_size = stack_size; + } + + _initial_thread_stack_size = align_size_down(_initial_thread_stack_size, page_size()); + _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size; +} +#endif + +//////////////////////////////////////////////////////////////////////////////// +// time support + +// Time since start-up in seconds to a fine granularity. +// Used by VMSelfDestructTimer and the MemProfiler. +double os::elapsedTime() { + + return (double)(os::elapsed_counter()) * 0.000001; +} + +jlong os::elapsed_counter() { + timeval time; + int status = gettimeofday(&time, NULL); + return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count; +} + +jlong os::elapsed_frequency() { + return (1000 * 1000); +} + +// XXX: For now, code this as if BSD does not support vtime. +bool os::supports_vtime() { return false; } +bool os::enable_vtime() { return false; } +bool os::vtime_enabled() { return false; } +double os::elapsedVTime() { + // better than nothing, but not much + return elapsedTime(); +} + +jlong os::javaTimeMillis() { + timeval time; + int status = gettimeofday(&time, NULL); + assert(status != -1, "bsd error"); + return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); +} + +#ifndef CLOCK_MONOTONIC +#define CLOCK_MONOTONIC (1) +#endif + +#ifdef __APPLE__ +void os::Bsd::clock_init() { + // XXXDARWIN: Investigate replacement monotonic clock +} +#elif defined(_ALLBSD_SOURCE) +void os::Bsd::clock_init() { + struct timespec res; + struct timespec tp; + if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 && + ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) { + // yes, monotonic clock is supported + _clock_gettime = ::clock_gettime; + } +} +#else +void os::Bsd::clock_init() { + // we do dlopen's in this particular order due to bug in bsd + // dynamical loader (see 6348968) leading to crash on exit + void* handle = dlopen("librt.so.1", RTLD_LAZY); + if (handle == NULL) { + handle = dlopen("librt.so", RTLD_LAZY); + } + + if (handle) { + int (*clock_getres_func)(clockid_t, struct timespec*) = + (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres"); + int (*clock_gettime_func)(clockid_t, struct timespec*) = + (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime"); + if (clock_getres_func && clock_gettime_func) { + // See if monotonic clock is supported by the kernel. Note that some + // early implementations simply return kernel jiffies (updated every + // 1/100 or 1/1000 second). It would be bad to use such a low res clock + // for nano time (though the monotonic property is still nice to have). + // It's fixed in newer kernels, however clock_getres() still returns + // 1/HZ. We check if clock_getres() works, but will ignore its reported + // resolution for now. Hopefully as people move to new kernels, this + // won't be a problem. + struct timespec res; + struct timespec tp; + if (clock_getres_func (CLOCK_MONOTONIC, &res) == 0 && + clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) { + // yes, monotonic clock is supported + _clock_gettime = clock_gettime_func; + } else { + // close librt if there is no monotonic clock + dlclose(handle); + } + } + } +} +#endif + +#ifndef _ALLBSD_SOURCE +#ifndef SYS_clock_getres + +#if defined(IA32) || defined(AMD64) +#define SYS_clock_getres IA32_ONLY(266) AMD64_ONLY(229) +#define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) +#else +#warning "SYS_clock_getres not defined for this platform, disabling fast_thread_cpu_time" +#define sys_clock_getres(x,y) -1 +#endif + +#else +#define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) +#endif + +void os::Bsd::fast_thread_clock_init() { + if (!UseBsdPosixThreadCPUClocks) { + return; + } + clockid_t clockid; + struct timespec tp; + int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) = + (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid"); + + // Switch to using fast clocks for thread cpu time if + // the sys_clock_getres() returns 0 error code. + // Note, that some kernels may support the current thread + // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks + // returned by the pthread_getcpuclockid(). + // If the fast Posix clocks are supported then the sys_clock_getres() + // must return at least tp.tv_sec == 0 which means a resolution + // better than 1 sec. This is extra check for reliability. + + if(pthread_getcpuclockid_func && + pthread_getcpuclockid_func(_main_thread, &clockid) == 0 && + sys_clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) { + + _supports_fast_thread_cpu_time = true; + _pthread_getcpuclockid = pthread_getcpuclockid_func; + } +} +#endif + +jlong os::javaTimeNanos() { + if (Bsd::supports_monotonic_clock()) { + struct timespec tp; + int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp); + assert(status == 0, "gettime error"); + jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); + return result; + } else { + timeval time; + int status = gettimeofday(&time, NULL); + assert(status != -1, "bsd error"); + jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); + return 1000 * usecs; + } +} + +void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { + if (Bsd::supports_monotonic_clock()) { + info_ptr->max_value = ALL_64_BITS; + + // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past + info_ptr->may_skip_backward = false; // not subject to resetting or drifting + info_ptr->may_skip_forward = false; // not subject to resetting or drifting + } else { + // gettimeofday - based on time in seconds since the Epoch thus does not wrap + info_ptr->max_value = ALL_64_BITS; + + // gettimeofday is a real time clock so it skips + info_ptr->may_skip_backward = true; + info_ptr->may_skip_forward = true; + } + + info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time +} + +// Return the real, user, and system times in seconds from an +// arbitrary fixed point in the past. +bool os::getTimesSecs(double* process_real_time, + double* process_user_time, + double* process_system_time) { + struct tms ticks; + clock_t real_ticks = times(&ticks); + + if (real_ticks == (clock_t) (-1)) { + return false; + } else { + double ticks_per_second = (double) clock_tics_per_sec; + *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; + *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; + *process_real_time = ((double) real_ticks) / ticks_per_second; + + return true; + } +} + + +char * os::local_time_string(char *buf, size_t buflen) { + struct tm t; + time_t long_time; + time(&long_time); + localtime_r(&long_time, &t); + jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", + t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, + t.tm_hour, t.tm_min, t.tm_sec); + return buf; +} + +struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { + return localtime_r(clock, res); +} + +//////////////////////////////////////////////////////////////////////////////// +// runtime exit support + +// Note: os::shutdown() might be called very early during initialization, or +// called from signal handler. Before adding something to os::shutdown(), make +// sure it is async-safe and can handle partially initialized VM. +void os::shutdown() { + + // allow PerfMemory to attempt cleanup of any persistent resources + perfMemory_exit(); + + // needs to remove object in file system + AttachListener::abort(); + + // flush buffered output, finish log files + ostream_abort(); + + // Check for abort hook + abort_hook_t abort_hook = Arguments::abort_hook(); + if (abort_hook != NULL) { + abort_hook(); + } + +} + +// Note: os::abort() might be called very early during initialization, or +// called from signal handler. Before adding something to os::abort(), make +// sure it is async-safe and can handle partially initialized VM. +void os::abort(bool dump_core) { + os::shutdown(); + if (dump_core) { +#ifndef PRODUCT + fdStream out(defaultStream::output_fd()); + out.print_raw("Current thread is "); + char buf[16]; + jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); + out.print_raw_cr(buf); + out.print_raw_cr("Dumping core ..."); +#endif + ::abort(); // dump core + } + + ::exit(1); +} + +// Die immediately, no exit hook, no abort hook, no cleanup. +void os::die() { + // _exit() on BsdThreads only kills current thread + ::abort(); +} + +// unused on bsd for now. +void os::set_error_file(const char *logfile) {} + + +// This method is a copy of JDK's sysGetLastErrorString +// from src/solaris/hpi/src/system_md.c + +size_t os::lasterror(char *buf, size_t len) { + + if (errno == 0) return 0; + + const char *s = ::strerror(errno); + size_t n = ::strlen(s); + if (n >= len) { + n = len - 1; + } + ::strncpy(buf, s, n); + buf[n] = '\0'; + return n; +} + +intx os::current_thread_id() { return (intx)pthread_self(); } +int os::current_process_id() { + + // Under the old bsd thread library, bsd gives each thread + // its own process id. Because of this each thread will return + // a different pid if this method were to return the result + // of getpid(2). Bsd provides no api that returns the pid + // of the launcher thread for the vm. This implementation + // returns a unique pid, the pid of the launcher thread + // that starts the vm 'process'. + + // Under the NPTL, getpid() returns the same pid as the + // launcher thread rather than a unique pid per thread. + // Use gettid() if you want the old pre NPTL behaviour. + + // if you are looking for the result of a call to getpid() that + // returns a unique pid for the calling thread, then look at the + // OSThread::thread_id() method in osThread_bsd.hpp file + + return (int)(_initial_pid ? _initial_pid : getpid()); +} + +// DLL functions + +#define JNI_LIB_PREFIX "lib" +#ifdef __APPLE__ +#define JNI_LIB_SUFFIX ".dylib" +#else +#define JNI_LIB_SUFFIX ".so" +#endif + +const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; } + +// This must be hard coded because it's the system's temporary +// directory not the java application's temp directory, ala java.io.tmpdir. +const char* os::get_temp_directory() { return "/tmp"; } + +static bool file_exists(const char* filename) { + struct stat statbuf; + if (filename == NULL || strlen(filename) == 0) { + return false; + } + return os::stat(filename, &statbuf) == 0; +} + +void os::dll_build_name(char* buffer, size_t buflen, + const char* pname, const char* fname) { + // Copied from libhpi + const size_t pnamelen = pname ? strlen(pname) : 0; + + // Quietly truncate on buffer overflow. Should be an error. + if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) { + *buffer = '\0'; + return; + } + + if (pnamelen == 0) { + snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname); + } else if (strchr(pname, *os::path_separator()) != NULL) { + int n; + char** pelements = split_path(pname, &n); + for (int i = 0 ; i < n ; i++) { + // Really shouldn't be NULL, but check can't hurt + if (pelements[i] == NULL || strlen(pelements[i]) == 0) { + continue; // skip the empty path values + } + snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, + pelements[i], fname); + if (file_exists(buffer)) { + break; + } + } + // release the storage + for (int i = 0 ; i < n ; i++) { + if (pelements[i] != NULL) { + FREE_C_HEAP_ARRAY(char, pelements[i]); + } + } + if (pelements != NULL) { + FREE_C_HEAP_ARRAY(char*, pelements); + } + } else { + snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname); + } +} + +const char* os::get_current_directory(char *buf, int buflen) { + return getcwd(buf, buflen); +} + +// check if addr is inside libjvm[_g].so +bool os::address_is_in_vm(address addr) { + static address libjvm_base_addr; + Dl_info dlinfo; + + if (libjvm_base_addr == NULL) { + dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo); + libjvm_base_addr = (address)dlinfo.dli_fbase; + assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); + } + + if (dladdr((void *)addr, &dlinfo)) { + if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; + } + + return false; +} + +bool os::dll_address_to_function_name(address addr, char *buf, + int buflen, int *offset) { + Dl_info dlinfo; + + if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) { + if (buf != NULL) { + if(!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) { + jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); + } + } + if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; + return true; + } else if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != 0) { + if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), + dlinfo.dli_fname, buf, buflen, offset) == Decoder::no_error) { + return true; + } + } + + if (buf != NULL) buf[0] = '\0'; + if (offset != NULL) *offset = -1; + return false; +} + +#ifdef _ALLBSD_SOURCE +// ported from solaris version +bool os::dll_address_to_library_name(address addr, char* buf, + int buflen, int* offset) { + Dl_info dlinfo; + + if (dladdr((void*)addr, &dlinfo)){ + if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); + if (offset) *offset = addr - (address)dlinfo.dli_fbase; + return true; + } else { + if (buf) buf[0] = '\0'; + if (offset) *offset = -1; + return false; + } +} +#else +struct _address_to_library_name { + address addr; // input : memory address + size_t buflen; // size of fname + char* fname; // output: library name + address base; // library base addr +}; + +static int address_to_library_name_callback(struct dl_phdr_info *info, + size_t size, void *data) { + int i; + bool found = false; + address libbase = NULL; + struct _address_to_library_name * d = (struct _address_to_library_name *)data; + + // iterate through all loadable segments + for (i = 0; i < info->dlpi_phnum; i++) { + address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); + if (info->dlpi_phdr[i].p_type == PT_LOAD) { + // base address of a library is the lowest address of its loaded + // segments. + if (libbase == NULL || libbase > segbase) { + libbase = segbase; + } + // see if 'addr' is within current segment + if (segbase <= d->addr && + d->addr < segbase + info->dlpi_phdr[i].p_memsz) { + found = true; + } + } + } + + // dlpi_name is NULL or empty if the ELF file is executable, return 0 + // so dll_address_to_library_name() can fall through to use dladdr() which + // can figure out executable name from argv[0]. + if (found && info->dlpi_name && info->dlpi_name[0]) { + d->base = libbase; + if (d->fname) { + jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name); + } + return 1; + } + return 0; +} + +bool os::dll_address_to_library_name(address addr, char* buf, + int buflen, int* offset) { + Dl_info dlinfo; + struct _address_to_library_name data; + + // There is a bug in old glibc dladdr() implementation that it could resolve + // to wrong library name if the .so file has a base address != NULL. Here + // we iterate through the program headers of all loaded libraries to find + // out which library 'addr' really belongs to. This workaround can be + // removed once the minimum requirement for glibc is moved to 2.3.x. + data.addr = addr; + data.fname = buf; + data.buflen = buflen; + data.base = NULL; + int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data); + + if (rslt) { + // buf already contains library name + if (offset) *offset = addr - data.base; + return true; + } else if (dladdr((void*)addr, &dlinfo)){ + if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); + if (offset) *offset = addr - (address)dlinfo.dli_fbase; + return true; + } else { + if (buf) buf[0] = '\0'; + if (offset) *offset = -1; + return false; + } +} +#endif + + // Loads .dll/.so and + // in case of error it checks if .dll/.so was built for the + // same architecture as Hotspot is running on + +#ifdef __APPLE__ +void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { + void * result= ::dlopen(filename, RTLD_LAZY); + if (result != NULL) { + // Successful loading + return result; + } + + // Read system error message into ebuf + ::strncpy(ebuf, ::dlerror(), ebuflen-1); + ebuf[ebuflen-1]='\0'; + + return NULL; +} +#else +void * os::dll_load(const char *filename, char *ebuf, int ebuflen) +{ + void * result= ::dlopen(filename, RTLD_LAZY); + if (result != NULL) { + // Successful loading + return result; + } + + Elf32_Ehdr elf_head; + + // Read system error message into ebuf + // It may or may not be overwritten below + ::strncpy(ebuf, ::dlerror(), ebuflen-1); + ebuf[ebuflen-1]='\0'; + int diag_msg_max_length=ebuflen-strlen(ebuf); + char* diag_msg_buf=ebuf+strlen(ebuf); + + if (diag_msg_max_length==0) { + // No more space in ebuf for additional diagnostics message + return NULL; + } + + + int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); + + if (file_descriptor < 0) { + // Can't open library, report dlerror() message + return NULL; + } + + bool failed_to_read_elf_head= + (sizeof(elf_head)!= + (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ; + + ::close(file_descriptor); + if (failed_to_read_elf_head) { + // file i/o error - report dlerror() msg + return NULL; + } + + typedef struct { + Elf32_Half code; // Actual value as defined in elf.h + Elf32_Half compat_class; // Compatibility of archs at VM's sense + char elf_class; // 32 or 64 bit + char endianess; // MSB or LSB + char* name; // String representation + } arch_t; + + #ifndef EM_486 + #define EM_486 6 /* Intel 80486 */ + #endif + + #ifndef EM_MIPS_RS3_LE + #define EM_MIPS_RS3_LE 10 /* MIPS */ + #endif + + #ifndef EM_PPC64 + #define EM_PPC64 21 /* PowerPC64 */ + #endif + + #ifndef EM_S390 + #define EM_S390 22 /* IBM System/390 */ + #endif + + #ifndef EM_IA_64 + #define EM_IA_64 50 /* HP/Intel IA-64 */ + #endif + + #ifndef EM_X86_64 + #define EM_X86_64 62 /* AMD x86-64 */ + #endif + + static const arch_t arch_array[]={ + {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, + {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, + {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, + {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, + {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, + {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, + {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, + {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, + {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, + {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, + {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, + {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, + {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, + {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, + {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, + {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"} + }; + + #if (defined IA32) + static Elf32_Half running_arch_code=EM_386; + #elif (defined AMD64) + static Elf32_Half running_arch_code=EM_X86_64; + #elif (defined IA64) + static Elf32_Half running_arch_code=EM_IA_64; + #elif (defined __sparc) && (defined _LP64) + static Elf32_Half running_arch_code=EM_SPARCV9; + #elif (defined __sparc) && (!defined _LP64) + static Elf32_Half running_arch_code=EM_SPARC; + #elif (defined __powerpc64__) + static Elf32_Half running_arch_code=EM_PPC64; + #elif (defined __powerpc__) + static Elf32_Half running_arch_code=EM_PPC; + #elif (defined ARM) + static Elf32_Half running_arch_code=EM_ARM; + #elif (defined S390) + static Elf32_Half running_arch_code=EM_S390; + #elif (defined ALPHA) + static Elf32_Half running_arch_code=EM_ALPHA; + #elif (defined MIPSEL) + static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; + #elif (defined PARISC) + static Elf32_Half running_arch_code=EM_PARISC; + #elif (defined MIPS) + static Elf32_Half running_arch_code=EM_MIPS; + #elif (defined M68K) + static Elf32_Half running_arch_code=EM_68K; + #else + #error Method os::dll_load requires that one of following is defined:\ + IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K + #endif + + // Identify compatability class for VM's architecture and library's architecture + // Obtain string descriptions for architectures + + arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; + int running_arch_index=-1; + + for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) { + if (running_arch_code == arch_array[i].code) { + running_arch_index = i; + } + if (lib_arch.code == arch_array[i].code) { + lib_arch.compat_class = arch_array[i].compat_class; + lib_arch.name = arch_array[i].name; + } + } + + assert(running_arch_index != -1, + "Didn't find running architecture code (running_arch_code) in arch_array"); + if (running_arch_index == -1) { + // Even though running architecture detection failed + // we may still continue with reporting dlerror() message + return NULL; + } + + if (lib_arch.endianess != arch_array[running_arch_index].endianess) { + ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); + return NULL; + } + +#ifndef S390 + if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { + ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); + return NULL; + } +#endif // !S390 + + if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { + if ( lib_arch.name!=NULL ) { + ::snprintf(diag_msg_buf, diag_msg_max_length-1, + " (Possible cause: can't load %s-bit .so on a %s-bit platform)", + lib_arch.name, arch_array[running_arch_index].name); + } else { + ::snprintf(diag_msg_buf, diag_msg_max_length-1, + " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", + lib_arch.code, + arch_array[running_arch_index].name); + } + } + + return NULL; +} +#endif /* !__APPLE__ */ + +// XXX: Do we need a lock around this as per Linux? +void* os::dll_lookup(void* handle, const char* name) { + return dlsym(handle, name); +} + + +static bool _print_ascii_file(const char* filename, outputStream* st) { + int fd = ::open(filename, O_RDONLY); + if (fd == -1) { + return false; + } + + char buf[32]; + int bytes; + while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) { + st->print_raw(buf, bytes); + } + + ::close(fd); + + return true; +} + +void os::print_dll_info(outputStream *st) { + st->print_cr("Dynamic libraries:"); +#ifdef _ALLBSD_SOURCE +#ifdef RTLD_DI_LINKMAP + Dl_info dli; + void *handle; + Link_map *map; + Link_map *p; + + if (!dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli)) { + st->print_cr("Error: Cannot print dynamic libraries."); + return; + } + handle = dlopen(dli.dli_fname, RTLD_LAZY); + if (handle == NULL) { + st->print_cr("Error: Cannot print dynamic libraries."); + return; + } + dlinfo(handle, RTLD_DI_LINKMAP, &map); + if (map == NULL) { + st->print_cr("Error: Cannot print dynamic libraries."); + return; + } + + while (map->l_prev != NULL) + map = map->l_prev; + + while (map != NULL) { + st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name); + map = map->l_next; + } + + dlclose(handle); +#elif defined(__APPLE__) + uint32_t count; + uint32_t i; + + count = _dyld_image_count(); + for (i = 1; i < count; i++) { + const char *name = _dyld_get_image_name(i); + intptr_t slide = _dyld_get_image_vmaddr_slide(i); + st->print_cr(PTR_FORMAT " \t%s", slide, name); + } +#else + st->print_cr("Error: Cannot print dynamic libraries."); +#endif +#else + char fname[32]; + pid_t pid = os::Bsd::gettid(); + + jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid); + + if (!_print_ascii_file(fname, st)) { + st->print("Can not get library information for pid = %d\n", pid); + } +#endif +} + + +void os::print_os_info(outputStream* st) { + st->print("OS:"); + + // Try to identify popular distros. + // Most Bsd distributions have /etc/XXX-release file, which contains + // the OS version string. Some have more than one /etc/XXX-release file + // (e.g. Mandrake has both /etc/mandrake-release and /etc/redhat-release.), + // so the order is important. + if (!_print_ascii_file("/etc/mandrake-release", st) && + !_print_ascii_file("/etc/sun-release", st) && + !_print_ascii_file("/etc/redhat-release", st) && + !_print_ascii_file("/etc/SuSE-release", st) && + !_print_ascii_file("/etc/turbobsd-release", st) && + !_print_ascii_file("/etc/gentoo-release", st) && + !_print_ascii_file("/etc/debian_version", st) && + !_print_ascii_file("/etc/ltib-release", st) && + !_print_ascii_file("/etc/angstrom-version", st)) { + st->print("Bsd"); + } + st->cr(); + + // kernel + st->print("uname:"); + struct utsname name; + uname(&name); + st->print(name.sysname); st->print(" "); + st->print(name.release); st->print(" "); + st->print(name.version); st->print(" "); + st->print(name.machine); + st->cr(); + +#ifndef _ALLBSD_SOURCE + // Print warning if unsafe chroot environment detected + if (unsafe_chroot_detected) { + st->print("WARNING!! "); + st->print_cr(unstable_chroot_error); + } + + // libc, pthread + st->print("libc:"); + st->print(os::Bsd::glibc_version()); st->print(" "); + st->print(os::Bsd::libpthread_version()); st->print(" "); + if (os::Bsd::is_BsdThreads()) { + st->print("(%s stack)", os::Bsd::is_floating_stack() ? "floating" : "fixed"); + } + st->cr(); +#endif + + // rlimit + st->print("rlimit:"); + struct rlimit rlim; + + st->print(" STACK "); + getrlimit(RLIMIT_STACK, &rlim); + if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); + else st->print("%uk", rlim.rlim_cur >> 10); + + st->print(", CORE "); + getrlimit(RLIMIT_CORE, &rlim); + if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); + else st->print("%uk", rlim.rlim_cur >> 10); + + st->print(", NPROC "); + getrlimit(RLIMIT_NPROC, &rlim); + if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); + else st->print("%d", rlim.rlim_cur); + + st->print(", NOFILE "); + getrlimit(RLIMIT_NOFILE, &rlim); + if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); + else st->print("%d", rlim.rlim_cur); + +#ifndef _ALLBSD_SOURCE + st->print(", AS "); + getrlimit(RLIMIT_AS, &rlim); + if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); + else st->print("%uk", rlim.rlim_cur >> 10); + st->cr(); + + // load average + st->print("load average:"); + double loadavg[3]; + os::loadavg(loadavg, 3); + st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]); + st->cr(); +#endif +} + +void os::pd_print_cpu_info(outputStream* st) { + // Nothing to do for now. +} + +void os::print_memory_info(outputStream* st) { + + st->print("Memory:"); + st->print(" %dk page", os::vm_page_size()>>10); + +#ifndef _ALLBSD_SOURCE + // values in struct sysinfo are "unsigned long" + struct sysinfo si; + sysinfo(&si); +#endif + + st->print(", physical " UINT64_FORMAT "k", + os::physical_memory() >> 10); + st->print("(" UINT64_FORMAT "k free)", + os::available_memory() >> 10); +#ifndef _ALLBSD_SOURCE + st->print(", swap " UINT64_FORMAT "k", + ((jlong)si.totalswap * si.mem_unit) >> 10); + st->print("(" UINT64_FORMAT "k free)", + ((jlong)si.freeswap * si.mem_unit) >> 10); +#endif + st->cr(); + + // meminfo + st->print("\n/proc/meminfo:\n"); + _print_ascii_file("/proc/meminfo", st); + st->cr(); +} + +// Taken from /usr/include/bits/siginfo.h Supposed to be architecture specific +// but they're the same for all the bsd arch that we support +// and they're the same for solaris but there's no common place to put this. +const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR", + "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG", + "ILL_COPROC", "ILL_BADSTK" }; + +const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV", + "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES", + "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" }; + +const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" }; + +const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" }; + +void os::print_siginfo(outputStream* st, void* siginfo) { + st->print("siginfo:"); + + const int buflen = 100; + char buf[buflen]; + siginfo_t *si = (siginfo_t*)siginfo; + st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen)); + if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) { + st->print("si_errno=%s", buf); + } else { + st->print("si_errno=%d", si->si_errno); + } + const int c = si->si_code; + assert(c > 0, "unexpected si_code"); + switch (si->si_signo) { + case SIGILL: + st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]); + st->print(", si_addr=" PTR_FORMAT, si->si_addr); + break; + case SIGFPE: + st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]); + st->print(", si_addr=" PTR_FORMAT, si->si_addr); + break; + case SIGSEGV: + st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]); + st->print(", si_addr=" PTR_FORMAT, si->si_addr); + break; + case SIGBUS: + st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]); + st->print(", si_addr=" PTR_FORMAT, si->si_addr); + break; + default: + st->print(", si_code=%d", si->si_code); + // no si_addr + } + + if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && + UseSharedSpaces) { + FileMapInfo* mapinfo = FileMapInfo::current_info(); + if (mapinfo->is_in_shared_space(si->si_addr)) { + st->print("\n\nError accessing class data sharing archive." \ + " Mapped file inaccessible during execution, " \ + " possible disk/network problem."); + } + } + st->cr(); +} + + +static void print_signal_handler(outputStream* st, int sig, + char* buf, size_t buflen); + +void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { + st->print_cr("Signal Handlers:"); + print_signal_handler(st, SIGSEGV, buf, buflen); + print_signal_handler(st, SIGBUS , buf, buflen); + print_signal_handler(st, SIGFPE , buf, buflen); + print_signal_handler(st, SIGPIPE, buf, buflen); + print_signal_handler(st, SIGXFSZ, buf, buflen); + print_signal_handler(st, SIGILL , buf, buflen); + print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); + print_signal_handler(st, SR_signum, buf, buflen); + print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); + print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); + print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); + print_signal_handler(st, BREAK_SIGNAL, buf, buflen); +} + +static char saved_jvm_path[MAXPATHLEN] = {0}; + +// Find the full path to the current module, libjvm.so or libjvm_g.so +void os::jvm_path(char *buf, jint buflen) { + // Error checking. + if (buflen < MAXPATHLEN) { + assert(false, "must use a large-enough buffer"); + buf[0] = '\0'; + return; + } + // Lazy resolve the path to current module. + if (saved_jvm_path[0] != 0) { + strcpy(buf, saved_jvm_path); + return; + } + + char dli_fname[MAXPATHLEN]; + bool ret = dll_address_to_library_name( + CAST_FROM_FN_PTR(address, os::jvm_path), + dli_fname, sizeof(dli_fname), NULL); + assert(ret != 0, "cannot locate libjvm"); + char *rp = realpath(dli_fname, buf); + if (rp == NULL) + return; + + if (Arguments::created_by_gamma_launcher()) { + // Support for the gamma launcher. Typical value for buf is + // "/jre/lib///libjvm.so". If "/jre/lib/" appears at + // the right place in the string, then assume we are installed in a JDK and + // we're done. Otherwise, check for a JAVA_HOME environment variable and fix + // up the path so it looks like libjvm.so is installed there (append a + // fake suffix hotspot/libjvm.so). + const char *p = buf + strlen(buf) - 1; + for (int count = 0; p > buf && count < 5; ++count) { + for (--p; p > buf && *p != '/'; --p) + /* empty */ ; + } + + if (strncmp(p, "/jre/lib/", 9) != 0) { + // Look for JAVA_HOME in the environment. + char* java_home_var = ::getenv("JAVA_HOME"); + if (java_home_var != NULL && java_home_var[0] != 0) { + char* jrelib_p; + int len; + + // Check the current module name "libjvm.so" or "libjvm_g.so". + p = strrchr(buf, '/'); + assert(strstr(p, "/libjvm") == p, "invalid library name"); + p = strstr(p, "_g") ? "_g" : ""; + + rp = realpath(java_home_var, buf); + if (rp == NULL) + return; + + // determine if this is a legacy image or modules image + // modules image doesn't have "jre" subdirectory + len = strlen(buf); + jrelib_p = buf + len; + snprintf(jrelib_p, buflen-len, "/jre/lib/%s", cpu_arch); + if (0 != access(buf, F_OK)) { + snprintf(jrelib_p, buflen-len, "/lib/%s", cpu_arch); + } + + if (0 == access(buf, F_OK)) { + // Use current module name "libjvm[_g].so" instead of + // "libjvm"debug_only("_g")".so" since for fastdebug version + // we should have "libjvm.so" but debug_only("_g") adds "_g"! + len = strlen(buf); + snprintf(buf + len, buflen-len, "/hotspot/libjvm%s.so", p); + } else { + // Go back to path of .so + rp = realpath(dli_fname, buf); + if (rp == NULL) + return; + } + } + } + } + + strcpy(saved_jvm_path, buf); +} + +void os::print_jni_name_prefix_on(outputStream* st, int args_size) { + // no prefix required, not even "_" +} + +void os::print_jni_name_suffix_on(outputStream* st, int args_size) { + // no suffix required +} + +//////////////////////////////////////////////////////////////////////////////// +// sun.misc.Signal support + +static volatile jint sigint_count = 0; + +static void +UserHandler(int sig, void *siginfo, void *context) { + // 4511530 - sem_post is serialized and handled by the manager thread. When + // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We + // don't want to flood the manager thread with sem_post requests. + if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) + return; + + // Ctrl-C is pressed during error reporting, likely because the error + // handler fails to abort. Let VM die immediately. + if (sig == SIGINT && is_error_reported()) { + os::die(); + } + + os::signal_notify(sig); +} + +void* os::user_handler() { + return CAST_FROM_FN_PTR(void*, UserHandler); +} + +extern "C" { + typedef void (*sa_handler_t)(int); + typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); +} + +void* os::signal(int signal_number, void* handler) { + struct sigaction sigAct, oldSigAct; + + sigfillset(&(sigAct.sa_mask)); + sigAct.sa_flags = SA_RESTART|SA_SIGINFO; + sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); + + if (sigaction(signal_number, &sigAct, &oldSigAct)) { + // -1 means registration failed + return (void *)-1; + } + + return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); +} + +void os::signal_raise(int signal_number) { + ::raise(signal_number); +} + +/* + * The following code is moved from os.cpp for making this + * code platform specific, which it is by its very nature. + */ + +// Will be modified when max signal is changed to be dynamic +int os::sigexitnum_pd() { + return NSIG; +} + +// a counter for each possible signal value +static volatile jint pending_signals[NSIG+1] = { 0 }; + +// Bsd(POSIX) specific hand shaking semaphore. +#ifdef __APPLE__ +static semaphore_t sig_sem; +#define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value) +#define SEM_WAIT(sem) semaphore_wait(sem); +#define SEM_POST(sem) semaphore_signal(sem); +#else +static sem_t sig_sem; +#define SEM_INIT(sem, value) sem_init(&sem, 0, value) +#define SEM_WAIT(sem) sem_wait(&sem); +#define SEM_POST(sem) sem_post(&sem); +#endif + +void os::signal_init_pd() { + // Initialize signal structures + ::memset((void*)pending_signals, 0, sizeof(pending_signals)); + + // Initialize signal semaphore + ::SEM_INIT(sig_sem, 0); +} + +void os::signal_notify(int sig) { + Atomic::inc(&pending_signals[sig]); + ::SEM_POST(sig_sem); +} + +static int check_pending_signals(bool wait) { + Atomic::store(0, &sigint_count); + for (;;) { + for (int i = 0; i < NSIG + 1; i++) { + jint n = pending_signals[i]; + if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { + return i; + } + } + if (!wait) { + return -1; + } + JavaThread *thread = JavaThread::current(); + ThreadBlockInVM tbivm(thread); + + bool threadIsSuspended; + do { + thread->set_suspend_equivalent(); + // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() + ::SEM_WAIT(sig_sem); + + // were we externally suspended while we were waiting? + threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); + if (threadIsSuspended) { + // + // The semaphore has been incremented, but while we were waiting + // another thread suspended us. We don't want to continue running + // while suspended because that would surprise the thread that + // suspended us. + // + ::SEM_POST(sig_sem); + + thread->java_suspend_self(); + } + } while (threadIsSuspended); + } +} + +int os::signal_lookup() { + return check_pending_signals(false); +} + +int os::signal_wait() { + return check_pending_signals(true); +} + +//////////////////////////////////////////////////////////////////////////////// +// Virtual Memory + +int os::vm_page_size() { + // Seems redundant as all get out + assert(os::Bsd::page_size() != -1, "must call os::init"); + return os::Bsd::page_size(); +} + +// Solaris allocates memory by pages. +int os::vm_allocation_granularity() { + assert(os::Bsd::page_size() != -1, "must call os::init"); + return os::Bsd::page_size(); +} + +// Rationale behind this function: +// current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable +// mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get +// samples for JITted code. Here we create private executable mapping over the code cache +// and then we can use standard (well, almost, as mapping can change) way to provide +// info for the reporting script by storing timestamp and location of symbol +void bsd_wrap_code(char* base, size_t size) { + static volatile jint cnt = 0; + + if (!UseOprofile) { + return; + } + + char buf[PATH_MAX + 1]; + int num = Atomic::add(1, &cnt); + + snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d", + os::get_temp_directory(), os::current_process_id(), num); + unlink(buf); + + int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); + + if (fd != -1) { + off_t rv = ::lseek(fd, size-2, SEEK_SET); + if (rv != (off_t)-1) { + if (::write(fd, "", 1) == 1) { + mmap(base, size, + PROT_READ|PROT_WRITE|PROT_EXEC, + MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); + } + } + ::close(fd); + unlink(buf); + } +} + +// NOTE: Bsd kernel does not really reserve the pages for us. +// All it does is to check if there are enough free pages +// left at the time of mmap(). This could be a potential +// problem. +bool os::commit_memory(char* addr, size_t size, bool exec) { + int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; +#ifdef __OpenBSD__ + // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD + return ::mprotect(addr, size, prot) == 0; +#else + uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, + MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); + return res != (uintptr_t) MAP_FAILED; +#endif +} + +#ifndef _ALLBSD_SOURCE +// Define MAP_HUGETLB here so we can build HotSpot on old systems. +#ifndef MAP_HUGETLB +#define MAP_HUGETLB 0x40000 +#endif + +// Define MADV_HUGEPAGE here so we can build HotSpot on old systems. +#ifndef MADV_HUGEPAGE +#define MADV_HUGEPAGE 14 +#endif +#endif + +bool os::commit_memory(char* addr, size_t size, size_t alignment_hint, + bool exec) { +#ifndef _ALLBSD_SOURCE + if (UseHugeTLBFS && alignment_hint > (size_t)vm_page_size()) { + int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; + uintptr_t res = + (uintptr_t) ::mmap(addr, size, prot, + MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS|MAP_HUGETLB, + -1, 0); + return res != (uintptr_t) MAP_FAILED; + } +#endif + + return commit_memory(addr, size, exec); +} + +void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) { +#ifndef _ALLBSD_SOURCE + if (UseHugeTLBFS && alignment_hint > (size_t)vm_page_size()) { + // We don't check the return value: madvise(MADV_HUGEPAGE) may not + // be supported or the memory may already be backed by huge pages. + ::madvise(addr, bytes, MADV_HUGEPAGE); + } +#endif +} + +void os::free_memory(char *addr, size_t bytes) { + ::madvise(addr, bytes, MADV_DONTNEED); +} + +void os::numa_make_global(char *addr, size_t bytes) { +} + +void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { +} + +bool os::numa_topology_changed() { return false; } + +size_t os::numa_get_groups_num() { + return 1; +} + +int os::numa_get_group_id() { + return 0; +} + +size_t os::numa_get_leaf_groups(int *ids, size_t size) { + if (size > 0) { + ids[0] = 0; + return 1; + } + return 0; +} + +bool os::get_page_info(char *start, page_info* info) { + return false; +} + +char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { + return end; +} + +#ifndef _ALLBSD_SOURCE +// Something to do with the numa-aware allocator needs these symbols +extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { } +extern "C" JNIEXPORT void numa_error(char *where) { } +extern "C" JNIEXPORT int fork1() { return fork(); } + + +// If we are running with libnuma version > 2, then we should +// be trying to use symbols with versions 1.1 +// If we are running with earlier version, which did not have symbol versions, +// we should use the base version. +void* os::Bsd::libnuma_dlsym(void* handle, const char *name) { + void *f = dlvsym(handle, name, "libnuma_1.1"); + if (f == NULL) { + f = dlsym(handle, name); + } + return f; +} + +bool os::Bsd::libnuma_init() { + // sched_getcpu() should be in libc. + set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, + dlsym(RTLD_DEFAULT, "sched_getcpu"))); + + if (sched_getcpu() != -1) { // Does it work? + void *handle = dlopen("libnuma.so.1", RTLD_LAZY); + if (handle != NULL) { + set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t, + libnuma_dlsym(handle, "numa_node_to_cpus"))); + set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t, + libnuma_dlsym(handle, "numa_max_node"))); + set_numa_available(CAST_TO_FN_PTR(numa_available_func_t, + libnuma_dlsym(handle, "numa_available"))); + set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t, + libnuma_dlsym(handle, "numa_tonode_memory"))); + set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t, + libnuma_dlsym(handle, "numa_interleave_memory"))); + + + if (numa_available() != -1) { + set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes")); + // Create a cpu -> node mapping + _cpu_to_node = new (ResourceObj::C_HEAP) GrowableArray(0, true); + rebuild_cpu_to_node_map(); + return true; + } + } + } + return false; +} + +// rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id. +// The table is later used in get_node_by_cpu(). +void os::Bsd::rebuild_cpu_to_node_map() { + const size_t NCPUS = 32768; // Since the buffer size computation is very obscure + // in libnuma (possible values are starting from 16, + // and continuing up with every other power of 2, but less + // than the maximum number of CPUs supported by kernel), and + // is a subject to change (in libnuma version 2 the requirements + // are more reasonable) we'll just hardcode the number they use + // in the library. + const size_t BitsPerCLong = sizeof(long) * CHAR_BIT; + + size_t cpu_num = os::active_processor_count(); + size_t cpu_map_size = NCPUS / BitsPerCLong; + size_t cpu_map_valid_size = + MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size); + + cpu_to_node()->clear(); + cpu_to_node()->at_grow(cpu_num - 1); + size_t node_num = numa_get_groups_num(); + + unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size); + for (size_t i = 0; i < node_num; i++) { + if (numa_node_to_cpus(i, cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) { + for (size_t j = 0; j < cpu_map_valid_size; j++) { + if (cpu_map[j] != 0) { + for (size_t k = 0; k < BitsPerCLong; k++) { + if (cpu_map[j] & (1UL << k)) { + cpu_to_node()->at_put(j * BitsPerCLong + k, i); + } + } + } + } + } + } + FREE_C_HEAP_ARRAY(unsigned long, cpu_map); +} + +int os::Bsd::get_node_by_cpu(int cpu_id) { + if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) { + return cpu_to_node()->at(cpu_id); + } + return -1; +} + +GrowableArray* os::Bsd::_cpu_to_node; +os::Bsd::sched_getcpu_func_t os::Bsd::_sched_getcpu; +os::Bsd::numa_node_to_cpus_func_t os::Bsd::_numa_node_to_cpus; +os::Bsd::numa_max_node_func_t os::Bsd::_numa_max_node; +os::Bsd::numa_available_func_t os::Bsd::_numa_available; +os::Bsd::numa_tonode_memory_func_t os::Bsd::_numa_tonode_memory; +os::Bsd::numa_interleave_memory_func_t os::Bsd::_numa_interleave_memory; +unsigned long* os::Bsd::_numa_all_nodes; +#endif + +bool os::uncommit_memory(char* addr, size_t size) { +#ifdef __OpenBSD__ + // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD + return ::mprotect(addr, size, PROT_NONE) == 0; +#else + uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, + MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); + return res != (uintptr_t) MAP_FAILED; +#endif +} + +bool os::create_stack_guard_pages(char* addr, size_t size) { + return os::commit_memory(addr, size); +} + +// If this is a growable mapping, remove the guard pages entirely by +// munmap()ping them. If not, just call uncommit_memory(). +bool os::remove_stack_guard_pages(char* addr, size_t size) { + return os::uncommit_memory(addr, size); +} + +static address _highest_vm_reserved_address = NULL; + +// If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory +// at 'requested_addr'. If there are existing memory mappings at the same +// location, however, they will be overwritten. If 'fixed' is false, +// 'requested_addr' is only treated as a hint, the return value may or +// may not start from the requested address. Unlike Bsd mmap(), this +// function returns NULL to indicate failure. +static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { + char * addr; + int flags; + + flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; + if (fixed) { + assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address"); + flags |= MAP_FIXED; + } + + // Map uncommitted pages PROT_READ and PROT_WRITE, change access + // to PROT_EXEC if executable when we commit the page. + addr = (char*)::mmap(requested_addr, bytes, PROT_READ|PROT_WRITE, + flags, -1, 0); + + if (addr != MAP_FAILED) { + // anon_mmap() should only get called during VM initialization, + // don't need lock (actually we can skip locking even it can be called + // from multiple threads, because _highest_vm_reserved_address is just a + // hint about the upper limit of non-stack memory regions.) + if ((address)addr + bytes > _highest_vm_reserved_address) { + _highest_vm_reserved_address = (address)addr + bytes; + } + } + + return addr == MAP_FAILED ? NULL : addr; +} + +// Don't update _highest_vm_reserved_address, because there might be memory +// regions above addr + size. If so, releasing a memory region only creates +// a hole in the address space, it doesn't help prevent heap-stack collision. +// +static int anon_munmap(char * addr, size_t size) { + return ::munmap(addr, size) == 0; +} + +char* os::reserve_memory(size_t bytes, char* requested_addr, + size_t alignment_hint) { + return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); +} + +bool os::release_memory(char* addr, size_t size) { + return anon_munmap(addr, size); +} + +static address highest_vm_reserved_address() { + return _highest_vm_reserved_address; +} + +static bool bsd_mprotect(char* addr, size_t size, int prot) { + // Bsd wants the mprotect address argument to be page aligned. + char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size()); + + // According to SUSv3, mprotect() should only be used with mappings + // established by mmap(), and mmap() always maps whole pages. Unaligned + // 'addr' likely indicates problem in the VM (e.g. trying to change + // protection of malloc'ed or statically allocated memory). Check the + // caller if you hit this assert. + assert(addr == bottom, "sanity check"); + + size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size()); + return ::mprotect(bottom, size, prot) == 0; +} + +// Set protections specified +bool os::protect_memory(char* addr, size_t bytes, ProtType prot, + bool is_committed) { + unsigned int p = 0; + switch (prot) { + case MEM_PROT_NONE: p = PROT_NONE; break; + case MEM_PROT_READ: p = PROT_READ; break; + case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; + case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; + default: + ShouldNotReachHere(); + } + // is_committed is unused. + return bsd_mprotect(addr, bytes, p); +} + +bool os::guard_memory(char* addr, size_t size) { + return bsd_mprotect(addr, size, PROT_NONE); +} + +bool os::unguard_memory(char* addr, size_t size) { + return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE); +} + +bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) { + bool result = false; +#ifndef _ALLBSD_SOURCE + void *p = mmap (NULL, page_size, PROT_READ|PROT_WRITE, + MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB, + -1, 0); + + if (p != (void *) -1) { + // We don't know if this really is a huge page or not. + FILE *fp = fopen("/proc/self/maps", "r"); + if (fp) { + while (!feof(fp)) { + char chars[257]; + long x = 0; + if (fgets(chars, sizeof(chars), fp)) { + if (sscanf(chars, "%lx-%*x", &x) == 1 + && x == (long)p) { + if (strstr (chars, "hugepage")) { + result = true; + break; + } + } + } + } + fclose(fp); + } + munmap (p, page_size); + if (result) + return true; + } + + if (warn) { + warning("HugeTLBFS is not supported by the operating system."); + } +#endif + + return result; +} + +/* +* Set the coredump_filter bits to include largepages in core dump (bit 6) +* +* From the coredump_filter documentation: +* +* - (bit 0) anonymous private memory +* - (bit 1) anonymous shared memory +* - (bit 2) file-backed private memory +* - (bit 3) file-backed shared memory +* - (bit 4) ELF header pages in file-backed private memory areas (it is +* effective only if the bit 2 is cleared) +* - (bit 5) hugetlb private memory +* - (bit 6) hugetlb shared memory +*/ +static void set_coredump_filter(void) { + FILE *f; + long cdm; + + if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) { + return; + } + + if (fscanf(f, "%lx", &cdm) != 1) { + fclose(f); + return; + } + + rewind(f); + + if ((cdm & LARGEPAGES_BIT) == 0) { + cdm |= LARGEPAGES_BIT; + fprintf(f, "%#lx", cdm); + } + + fclose(f); +} + +// Large page support + +static size_t _large_page_size = 0; + +void os::large_page_init() { +#ifndef _ALLBSD_SOURCE + if (!UseLargePages) { + UseHugeTLBFS = false; + UseSHM = false; + return; + } + + if (FLAG_IS_DEFAULT(UseHugeTLBFS) && FLAG_IS_DEFAULT(UseSHM)) { + // If UseLargePages is specified on the command line try both methods, + // if it's default, then try only HugeTLBFS. + if (FLAG_IS_DEFAULT(UseLargePages)) { + UseHugeTLBFS = true; + } else { + UseHugeTLBFS = UseSHM = true; + } + } + + if (LargePageSizeInBytes) { + _large_page_size = LargePageSizeInBytes; + } else { + // large_page_size on Bsd is used to round up heap size. x86 uses either + // 2M or 4M page, depending on whether PAE (Physical Address Extensions) + // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use + // page as large as 256M. + // + // Here we try to figure out page size by parsing /proc/meminfo and looking + // for a line with the following format: + // Hugepagesize: 2048 kB + // + // If we can't determine the value (e.g. /proc is not mounted, or the text + // format has been changed), we'll use the largest page size supported by + // the processor. + +#ifndef ZERO + _large_page_size = IA32_ONLY(4 * M) AMD64_ONLY(2 * M) IA64_ONLY(256 * M) SPARC_ONLY(4 * M) + ARM_ONLY(2 * M) PPC_ONLY(4 * M); +#endif // ZERO + + FILE *fp = fopen("/proc/meminfo", "r"); + if (fp) { + while (!feof(fp)) { + int x = 0; + char buf[16]; + if (fscanf(fp, "Hugepagesize: %d", &x) == 1) { + if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) { + _large_page_size = x * K; + break; + } + } else { + // skip to next line + for (;;) { + int ch = fgetc(fp); + if (ch == EOF || ch == (int)'\n') break; + } + } + } + fclose(fp); + } + } + + // print a warning if any large page related flag is specified on command line + bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS); + + const size_t default_page_size = (size_t)Bsd::page_size(); + if (_large_page_size > default_page_size) { + _page_sizes[0] = _large_page_size; + _page_sizes[1] = default_page_size; + _page_sizes[2] = 0; + } + UseHugeTLBFS = UseHugeTLBFS && + Bsd::hugetlbfs_sanity_check(warn_on_failure, _large_page_size); + + if (UseHugeTLBFS) + UseSHM = false; + + UseLargePages = UseHugeTLBFS || UseSHM; + + set_coredump_filter(); +#endif +} + +#ifndef _ALLBSD_SOURCE +#ifndef SHM_HUGETLB +#define SHM_HUGETLB 04000 +#endif +#endif + +char* os::reserve_memory_special(size_t bytes, char* req_addr, bool exec) { + // "exec" is passed in but not used. Creating the shared image for + // the code cache doesn't have an SHM_X executable permission to check. + assert(UseLargePages && UseSHM, "only for SHM large pages"); + + key_t key = IPC_PRIVATE; + char *addr; + + bool warn_on_failure = UseLargePages && + (!FLAG_IS_DEFAULT(UseLargePages) || + !FLAG_IS_DEFAULT(LargePageSizeInBytes) + ); + char msg[128]; + + // Create a large shared memory region to attach to based on size. + // Currently, size is the total size of the heap +#ifndef _ALLBSD_SOURCE + int shmid = shmget(key, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W); +#else + int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W); +#endif + if (shmid == -1) { + // Possible reasons for shmget failure: + // 1. shmmax is too small for Java heap. + // > check shmmax value: cat /proc/sys/kernel/shmmax + // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax + // 2. not enough large page memory. + // > check available large pages: cat /proc/meminfo + // > increase amount of large pages: + // echo new_value > /proc/sys/vm/nr_hugepages + // Note 1: different Bsd may use different name for this property, + // e.g. on Redhat AS-3 it is "hugetlb_pool". + // Note 2: it's possible there's enough physical memory available but + // they are so fragmented after a long run that they can't + // coalesce into large pages. Try to reserve large pages when + // the system is still "fresh". + if (warn_on_failure) { + jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno); + warning(msg); + } + return NULL; + } + + // attach to the region + addr = (char*)shmat(shmid, req_addr, 0); + int err = errno; + + // Remove shmid. If shmat() is successful, the actual shared memory segment + // will be deleted when it's detached by shmdt() or when the process + // terminates. If shmat() is not successful this will remove the shared + // segment immediately. + shmctl(shmid, IPC_RMID, NULL); + + if ((intptr_t)addr == -1) { + if (warn_on_failure) { + jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err); + warning(msg); + } + return NULL; + } + + return addr; +} + +bool os::release_memory_special(char* base, size_t bytes) { + // detaching the SHM segment will also delete it, see reserve_memory_special() + int rslt = shmdt(base); + return rslt == 0; +} + +size_t os::large_page_size() { + return _large_page_size; +} + +// HugeTLBFS allows application to commit large page memory on demand; +// with SysV SHM the entire memory region must be allocated as shared +// memory. +bool os::can_commit_large_page_memory() { + return UseHugeTLBFS; +} + +bool os::can_execute_large_page_memory() { + return UseHugeTLBFS; +} + +// Reserve memory at an arbitrary address, only if that area is +// available (and not reserved for something else). + +char* os::attempt_reserve_memory_at(size_t bytes, char* requested_addr) { + const int max_tries = 10; + char* base[max_tries]; + size_t size[max_tries]; + const size_t gap = 0x000000; + + // Assert only that the size is a multiple of the page size, since + // that's all that mmap requires, and since that's all we really know + // about at this low abstraction level. If we need higher alignment, + // we can either pass an alignment to this method or verify alignment + // in one of the methods further up the call chain. See bug 5044738. + assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); + + // Repeatedly allocate blocks until the block is allocated at the + // right spot. Give up after max_tries. Note that reserve_memory() will + // automatically update _highest_vm_reserved_address if the call is + // successful. The variable tracks the highest memory address every reserved + // by JVM. It is used to detect heap-stack collision if running with + // fixed-stack BsdThreads. Because here we may attempt to reserve more + // space than needed, it could confuse the collision detecting code. To + // solve the problem, save current _highest_vm_reserved_address and + // calculate the correct value before return. + address old_highest = _highest_vm_reserved_address; + + // Bsd mmap allows caller to pass an address as hint; give it a try first, + // if kernel honors the hint then we can return immediately. + char * addr = anon_mmap(requested_addr, bytes, false); + if (addr == requested_addr) { + return requested_addr; + } + + if (addr != NULL) { + // mmap() is successful but it fails to reserve at the requested address + anon_munmap(addr, bytes); + } + + int i; + for (i = 0; i < max_tries; ++i) { + base[i] = reserve_memory(bytes); + + if (base[i] != NULL) { + // Is this the block we wanted? + if (base[i] == requested_addr) { + size[i] = bytes; + break; + } + + // Does this overlap the block we wanted? Give back the overlapped + // parts and try again. + + size_t top_overlap = requested_addr + (bytes + gap) - base[i]; + if (top_overlap >= 0 && top_overlap < bytes) { + unmap_memory(base[i], top_overlap); + base[i] += top_overlap; + size[i] = bytes - top_overlap; + } else { + size_t bottom_overlap = base[i] + bytes - requested_addr; + if (bottom_overlap >= 0 && bottom_overlap < bytes) { + unmap_memory(requested_addr, bottom_overlap); + size[i] = bytes - bottom_overlap; + } else { + size[i] = bytes; + } + } + } + } + + // Give back the unused reserved pieces. + + for (int j = 0; j < i; ++j) { + if (base[j] != NULL) { + unmap_memory(base[j], size[j]); + } + } + + if (i < max_tries) { + _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes); + return requested_addr; + } else { + _highest_vm_reserved_address = old_highest; + return NULL; + } +} + +size_t os::read(int fd, void *buf, unsigned int nBytes) { + RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes)); +} + +// TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation. +// Solaris uses poll(), bsd uses park(). +// Poll() is likely a better choice, assuming that Thread.interrupt() +// generates a SIGUSRx signal. Note that SIGUSR1 can interfere with +// SIGSEGV, see 4355769. + +const int NANOSECS_PER_MILLISECS = 1000000; + +int os::sleep(Thread* thread, jlong millis, bool interruptible) { + assert(thread == Thread::current(), "thread consistency check"); + + ParkEvent * const slp = thread->_SleepEvent ; + slp->reset() ; + OrderAccess::fence() ; + + if (interruptible) { + jlong prevtime = javaTimeNanos(); + + for (;;) { + if (os::is_interrupted(thread, true)) { + return OS_INTRPT; + } + + jlong newtime = javaTimeNanos(); + + if (newtime - prevtime < 0) { + // time moving backwards, should only happen if no monotonic clock + // not a guarantee() because JVM should not abort on kernel/glibc bugs + assert(!Bsd::supports_monotonic_clock(), "time moving backwards"); + } else { + millis -= (newtime - prevtime) / NANOSECS_PER_MILLISECS; + } + + if(millis <= 0) { + return OS_OK; + } + + prevtime = newtime; + + { + assert(thread->is_Java_thread(), "sanity check"); + JavaThread *jt = (JavaThread *) thread; + ThreadBlockInVM tbivm(jt); + OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */); + + jt->set_suspend_equivalent(); + // cleared by handle_special_suspend_equivalent_condition() or + // java_suspend_self() via check_and_wait_while_suspended() + + slp->park(millis); + + // were we externally suspended while we were waiting? + jt->check_and_wait_while_suspended(); + } + } + } else { + OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); + jlong prevtime = javaTimeNanos(); + + for (;;) { + // It'd be nice to avoid the back-to-back javaTimeNanos() calls on + // the 1st iteration ... + jlong newtime = javaTimeNanos(); + + if (newtime - prevtime < 0) { + // time moving backwards, should only happen if no monotonic clock + // not a guarantee() because JVM should not abort on kernel/glibc bugs + assert(!Bsd::supports_monotonic_clock(), "time moving backwards"); + } else { + millis -= (newtime - prevtime) / NANOSECS_PER_MILLISECS; + } + + if(millis <= 0) break ; + + prevtime = newtime; + slp->park(millis); + } + return OS_OK ; + } +} + +int os::naked_sleep() { + // %% make the sleep time an integer flag. for now use 1 millisec. + return os::sleep(Thread::current(), 1, false); +} + +// Sleep forever; naked call to OS-specific sleep; use with CAUTION +void os::infinite_sleep() { + while (true) { // sleep forever ... + ::sleep(100); // ... 100 seconds at a time + } +} + +// Used to convert frequent JVM_Yield() to nops +bool os::dont_yield() { + return DontYieldALot; +} + +void os::yield() { + sched_yield(); +} + +os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;} + +void os::yield_all(int attempts) { + // Yields to all threads, including threads with lower priorities + // Threads on Bsd are all with same priority. The Solaris style + // os::yield_all() with nanosleep(1ms) is not necessary. + sched_yield(); +} + +// Called from the tight loops to possibly influence time-sharing heuristics +void os::loop_breaker(int attempts) { + os::yield_all(attempts); +} + +//////////////////////////////////////////////////////////////////////////////// +// thread priority support + +// Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER +// only supports dynamic priority, static priority must be zero. For real-time +// applications, Bsd supports SCHED_RR which allows static priority (1-99). +// However, for large multi-threaded applications, SCHED_RR is not only slower +// than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out +// of 5 runs - Sep 2005). +// +// The following code actually changes the niceness of kernel-thread/LWP. It +// has an assumption that setpriority() only modifies one kernel-thread/LWP, +// not the entire user process, and user level threads are 1:1 mapped to kernel +// threads. It has always been the case, but could change in the future. For +// this reason, the code should not be used as default (ThreadPriorityPolicy=0). +// It is only used when ThreadPriorityPolicy=1 and requires root privilege. + +#if defined(_ALLBSD_SOURCE) && !defined(__APPLE__) +int os::java_to_os_priority[MaxPriority + 1] = { + 19, // 0 Entry should never be used + + 0, // 1 MinPriority + 3, // 2 + 6, // 3 + + 10, // 4 + 15, // 5 NormPriority + 18, // 6 + + 21, // 7 + 25, // 8 + 28, // 9 NearMaxPriority + + 31 // 10 MaxPriority +}; +#elif defined(__APPLE__) +/* Using Mach high-level priority assignments */ +int os::java_to_os_priority[MaxPriority + 1] = { + 0, // 0 Entry should never be used (MINPRI_USER) + + 27, // 1 MinPriority + 28, // 2 + 29, // 3 + + 30, // 4 + 31, // 5 NormPriority (BASEPRI_DEFAULT) + 32, // 6 + + 33, // 7 + 34, // 8 + 35, // 9 NearMaxPriority + + 36 // 10 MaxPriority +}; +#else +int os::java_to_os_priority[MaxPriority + 1] = { + 19, // 0 Entry should never be used + + 4, // 1 MinPriority + 3, // 2 + 2, // 3 + + 1, // 4 + 0, // 5 NormPriority + -1, // 6 + + -2, // 7 + -3, // 8 + -4, // 9 NearMaxPriority + + -5 // 10 MaxPriority +}; +#endif + +static int prio_init() { + if (ThreadPriorityPolicy == 1) { + // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 + // if effective uid is not root. Perhaps, a more elegant way of doing + // this is to test CAP_SYS_NICE capability, but that will require libcap.so + if (geteuid() != 0) { + if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { + warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd"); + } + ThreadPriorityPolicy = 0; + } + } + return 0; +} + +OSReturn os::set_native_priority(Thread* thread, int newpri) { + if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK; + +#ifdef __OpenBSD__ + // OpenBSD pthread_setprio starves low priority threads + return OS_OK; +#elif defined(__FreeBSD__) + int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri); +#elif defined(__APPLE__) || defined(__NetBSD__) + struct sched_param sp; + int policy; + pthread_t self = pthread_self(); + + if (pthread_getschedparam(self, &policy, &sp) != 0) + return OS_ERR; + + sp.sched_priority = newpri; + if (pthread_setschedparam(self, policy, &sp) != 0) + return OS_ERR; + + return OS_OK; +#else + int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); + return (ret == 0) ? OS_OK : OS_ERR; +#endif +} + +OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { + if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) { + *priority_ptr = java_to_os_priority[NormPriority]; + return OS_OK; + } + + errno = 0; +#if defined(__OpenBSD__) || defined(__FreeBSD__) + *priority_ptr = pthread_getprio(thread->osthread()->pthread_id()); +#elif defined(__APPLE__) || defined(__NetBSD__) + int policy; + struct sched_param sp; + + pthread_getschedparam(pthread_self(), &policy, &sp); + *priority_ptr = sp.sched_priority; +#else + *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); +#endif + return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); +} + +// Hint to the underlying OS that a task switch would not be good. +// Void return because it's a hint and can fail. +void os::hint_no_preempt() {} + +//////////////////////////////////////////////////////////////////////////////// +// suspend/resume support + +// the low-level signal-based suspend/resume support is a remnant from the +// old VM-suspension that used to be for java-suspension, safepoints etc, +// within hotspot. Now there is a single use-case for this: +// - calling get_thread_pc() on the VMThread by the flat-profiler task +// that runs in the watcher thread. +// The remaining code is greatly simplified from the more general suspension +// code that used to be used. +// +// The protocol is quite simple: +// - suspend: +// - sends a signal to the target thread +// - polls the suspend state of the osthread using a yield loop +// - target thread signal handler (SR_handler) sets suspend state +// and blocks in sigsuspend until continued +// - resume: +// - sets target osthread state to continue +// - sends signal to end the sigsuspend loop in the SR_handler +// +// Note that the SR_lock plays no role in this suspend/resume protocol. +// + +static void resume_clear_context(OSThread *osthread) { + osthread->set_ucontext(NULL); + osthread->set_siginfo(NULL); + + // notify the suspend action is completed, we have now resumed + osthread->sr.clear_suspended(); +} + +static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { + osthread->set_ucontext(context); + osthread->set_siginfo(siginfo); +} + +// +// Handler function invoked when a thread's execution is suspended or +// resumed. We have to be careful that only async-safe functions are +// called here (Note: most pthread functions are not async safe and +// should be avoided.) +// +// Note: sigwait() is a more natural fit than sigsuspend() from an +// interface point of view, but sigwait() prevents the signal hander +// from being run. libpthread would get very confused by not having +// its signal handlers run and prevents sigwait()'s use with the +// mutex granting granting signal. +// +// Currently only ever called on the VMThread +// +static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { + // Save and restore errno to avoid confusing native code with EINTR + // after sigsuspend. + int old_errno = errno; + + Thread* thread = Thread::current(); + OSThread* osthread = thread->osthread(); + assert(thread->is_VM_thread(), "Must be VMThread"); + // read current suspend action + int action = osthread->sr.suspend_action(); + if (action == SR_SUSPEND) { + suspend_save_context(osthread, siginfo, context); + + // Notify the suspend action is about to be completed. do_suspend() + // waits until SR_SUSPENDED is set and then returns. We will wait + // here for a resume signal and that completes the suspend-other + // action. do_suspend/do_resume is always called as a pair from + // the same thread - so there are no races + + // notify the caller + osthread->sr.set_suspended(); + + sigset_t suspend_set; // signals for sigsuspend() + + // get current set of blocked signals and unblock resume signal + pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); + sigdelset(&suspend_set, SR_signum); + + // wait here until we are resumed + do { + sigsuspend(&suspend_set); + // ignore all returns until we get a resume signal + } while (osthread->sr.suspend_action() != SR_CONTINUE); + + resume_clear_context(osthread); + + } else { + assert(action == SR_CONTINUE, "unexpected sr action"); + // nothing special to do - just leave the handler + } + + errno = old_errno; +} + + +static int SR_initialize() { + struct sigaction act; + char *s; + /* Get signal number to use for suspend/resume */ + if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { + int sig = ::strtol(s, 0, 10); + if (sig > 0 || sig < NSIG) { + SR_signum = sig; + } + } + + assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, + "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); + + sigemptyset(&SR_sigset); + sigaddset(&SR_sigset, SR_signum); + + /* Set up signal handler for suspend/resume */ + act.sa_flags = SA_RESTART|SA_SIGINFO; + act.sa_handler = (void (*)(int)) SR_handler; + + // SR_signum is blocked by default. + // 4528190 - We also need to block pthread restart signal (32 on all + // supported Bsd platforms). Note that BsdThreads need to block + // this signal for all threads to work properly. So we don't have + // to use hard-coded signal number when setting up the mask. + pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); + + if (sigaction(SR_signum, &act, 0) == -1) { + return -1; + } + + // Save signal flag + os::Bsd::set_our_sigflags(SR_signum, act.sa_flags); + return 0; +} + +static int SR_finalize() { + return 0; +} + + +// returns true on success and false on error - really an error is fatal +// but this seems the normal response to library errors +static bool do_suspend(OSThread* osthread) { + // mark as suspended and send signal + osthread->sr.set_suspend_action(SR_SUSPEND); + int status = pthread_kill(osthread->pthread_id(), SR_signum); + assert_status(status == 0, status, "pthread_kill"); + + // check status and wait until notified of suspension + if (status == 0) { + for (int i = 0; !osthread->sr.is_suspended(); i++) { + os::yield_all(i); + } + osthread->sr.set_suspend_action(SR_NONE); + return true; + } + else { + osthread->sr.set_suspend_action(SR_NONE); + return false; + } +} + +static void do_resume(OSThread* osthread) { + assert(osthread->sr.is_suspended(), "thread should be suspended"); + osthread->sr.set_suspend_action(SR_CONTINUE); + + int status = pthread_kill(osthread->pthread_id(), SR_signum); + assert_status(status == 0, status, "pthread_kill"); + // check status and wait unit notified of resumption + if (status == 0) { + for (int i = 0; osthread->sr.is_suspended(); i++) { + os::yield_all(i); + } + } + osthread->sr.set_suspend_action(SR_NONE); +} + +//////////////////////////////////////////////////////////////////////////////// +// interrupt support + +void os::interrupt(Thread* thread) { + assert(Thread::current() == thread || Threads_lock->owned_by_self(), + "possibility of dangling Thread pointer"); + + OSThread* osthread = thread->osthread(); + + if (!osthread->interrupted()) { + osthread->set_interrupted(true); + // More than one thread can get here with the same value of osthread, + // resulting in multiple notifications. We do, however, want the store + // to interrupted() to be visible to other threads before we execute unpark(). + OrderAccess::fence(); + ParkEvent * const slp = thread->_SleepEvent ; + if (slp != NULL) slp->unpark() ; + } + + // For JSR166. Unpark even if interrupt status already was set + if (thread->is_Java_thread()) + ((JavaThread*)thread)->parker()->unpark(); + + ParkEvent * ev = thread->_ParkEvent ; + if (ev != NULL) ev->unpark() ; + +} + +bool os::is_interrupted(Thread* thread, bool clear_interrupted) { + assert(Thread::current() == thread || Threads_lock->owned_by_self(), + "possibility of dangling Thread pointer"); + + OSThread* osthread = thread->osthread(); + + bool interrupted = osthread->interrupted(); + + if (interrupted && clear_interrupted) { + osthread->set_interrupted(false); + // consider thread->_SleepEvent->reset() ... optional optimization + } + + return interrupted; +} + +/////////////////////////////////////////////////////////////////////////////////// +// signal handling (except suspend/resume) + +// This routine may be used by user applications as a "hook" to catch signals. +// The user-defined signal handler must pass unrecognized signals to this +// routine, and if it returns true (non-zero), then the signal handler must +// return immediately. If the flag "abort_if_unrecognized" is true, then this +// routine will never retun false (zero), but instead will execute a VM panic +// routine kill the process. +// +// If this routine returns false, it is OK to call it again. This allows +// the user-defined signal handler to perform checks either before or after +// the VM performs its own checks. Naturally, the user code would be making +// a serious error if it tried to handle an exception (such as a null check +// or breakpoint) that the VM was generating for its own correct operation. +// +// This routine may recognize any of the following kinds of signals: +// SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. +// It should be consulted by handlers for any of those signals. +// +// The caller of this routine must pass in the three arguments supplied +// to the function referred to in the "sa_sigaction" (not the "sa_handler") +// field of the structure passed to sigaction(). This routine assumes that +// the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. +// +// Note that the VM will print warnings if it detects conflicting signal +// handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". +// +extern "C" JNIEXPORT int +JVM_handle_bsd_signal(int signo, siginfo_t* siginfo, + void* ucontext, int abort_if_unrecognized); + +void signalHandler(int sig, siginfo_t* info, void* uc) { + assert(info != NULL && uc != NULL, "it must be old kernel"); + JVM_handle_bsd_signal(sig, info, uc, true); +} + + +// This boolean allows users to forward their own non-matching signals +// to JVM_handle_bsd_signal, harmlessly. +bool os::Bsd::signal_handlers_are_installed = false; + +// For signal-chaining +struct sigaction os::Bsd::sigact[MAXSIGNUM]; +unsigned int os::Bsd::sigs = 0; +bool os::Bsd::libjsig_is_loaded = false; +typedef struct sigaction *(*get_signal_t)(int); +get_signal_t os::Bsd::get_signal_action = NULL; + +struct sigaction* os::Bsd::get_chained_signal_action(int sig) { + struct sigaction *actp = NULL; + + if (libjsig_is_loaded) { + // Retrieve the old signal handler from libjsig + actp = (*get_signal_action)(sig); + } + if (actp == NULL) { + // Retrieve the preinstalled signal handler from jvm + actp = get_preinstalled_handler(sig); + } + + return actp; +} + +static bool call_chained_handler(struct sigaction *actp, int sig, + siginfo_t *siginfo, void *context) { + // Call the old signal handler + if (actp->sa_handler == SIG_DFL) { + // It's more reasonable to let jvm treat it as an unexpected exception + // instead of taking the default action. + return false; + } else if (actp->sa_handler != SIG_IGN) { + if ((actp->sa_flags & SA_NODEFER) == 0) { + // automaticlly block the signal + sigaddset(&(actp->sa_mask), sig); + } + + sa_handler_t hand; + sa_sigaction_t sa; + bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; + // retrieve the chained handler + if (siginfo_flag_set) { + sa = actp->sa_sigaction; + } else { + hand = actp->sa_handler; + } + + if ((actp->sa_flags & SA_RESETHAND) != 0) { + actp->sa_handler = SIG_DFL; + } + + // try to honor the signal mask + sigset_t oset; + pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); + + // call into the chained handler + if (siginfo_flag_set) { + (*sa)(sig, siginfo, context); + } else { + (*hand)(sig); + } + + // restore the signal mask + pthread_sigmask(SIG_SETMASK, &oset, 0); + } + // Tell jvm's signal handler the signal is taken care of. + return true; +} + +bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) { + bool chained = false; + // signal-chaining + if (UseSignalChaining) { + struct sigaction *actp = get_chained_signal_action(sig); + if (actp != NULL) { + chained = call_chained_handler(actp, sig, siginfo, context); + } + } + return chained; +} + +struct sigaction* os::Bsd::get_preinstalled_handler(int sig) { + if ((( (unsigned int)1 << sig ) & sigs) != 0) { + return &sigact[sig]; + } + return NULL; +} + +void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) { + assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); + sigact[sig] = oldAct; + sigs |= (unsigned int)1 << sig; +} + +// for diagnostic +int os::Bsd::sigflags[MAXSIGNUM]; + +int os::Bsd::get_our_sigflags(int sig) { + assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); + return sigflags[sig]; +} + +void os::Bsd::set_our_sigflags(int sig, int flags) { + assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); + sigflags[sig] = flags; +} + +void os::Bsd::set_signal_handler(int sig, bool set_installed) { + // Check for overwrite. + struct sigaction oldAct; + sigaction(sig, (struct sigaction*)NULL, &oldAct); + + void* oldhand = oldAct.sa_sigaction + ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) + : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); + if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && + oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && + oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { + if (AllowUserSignalHandlers || !set_installed) { + // Do not overwrite; user takes responsibility to forward to us. + return; + } else if (UseSignalChaining) { + // save the old handler in jvm + save_preinstalled_handler(sig, oldAct); + // libjsig also interposes the sigaction() call below and saves the + // old sigaction on it own. + } else { + fatal(err_msg("Encountered unexpected pre-existing sigaction handler " + "%#lx for signal %d.", (long)oldhand, sig)); + } + } + + struct sigaction sigAct; + sigfillset(&(sigAct.sa_mask)); + sigAct.sa_handler = SIG_DFL; + if (!set_installed) { + sigAct.sa_flags = SA_SIGINFO|SA_RESTART; + } else { + sigAct.sa_sigaction = signalHandler; + sigAct.sa_flags = SA_SIGINFO|SA_RESTART; + } + // Save flags, which are set by ours + assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); + sigflags[sig] = sigAct.sa_flags; + + int ret = sigaction(sig, &sigAct, &oldAct); + assert(ret == 0, "check"); + + void* oldhand2 = oldAct.sa_sigaction + ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) + : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); + assert(oldhand2 == oldhand, "no concurrent signal handler installation"); +} + +// install signal handlers for signals that HotSpot needs to +// handle in order to support Java-level exception handling. + +void os::Bsd::install_signal_handlers() { + if (!signal_handlers_are_installed) { + signal_handlers_are_installed = true; + + // signal-chaining + typedef void (*signal_setting_t)(); + signal_setting_t begin_signal_setting = NULL; + signal_setting_t end_signal_setting = NULL; + begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, + dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); + if (begin_signal_setting != NULL) { + end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, + dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); + get_signal_action = CAST_TO_FN_PTR(get_signal_t, + dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); + libjsig_is_loaded = true; + assert(UseSignalChaining, "should enable signal-chaining"); + } + if (libjsig_is_loaded) { + // Tell libjsig jvm is setting signal handlers + (*begin_signal_setting)(); + } + + set_signal_handler(SIGSEGV, true); + set_signal_handler(SIGPIPE, true); + set_signal_handler(SIGBUS, true); + set_signal_handler(SIGILL, true); + set_signal_handler(SIGFPE, true); + set_signal_handler(SIGXFSZ, true); + +#if defined(__APPLE__) + // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including + // signals caught and handled by the JVM. To work around this, we reset the mach task + // signal handler that's placed on our process by CrashReporter. This disables + // CrashReporter-based reporting. + // + // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes + // on caught fatal signals. + // + // Additionally, gdb installs both standard BSD signal handlers, and mach exception + // handlers. By replacing the existing task exception handler, we disable gdb's mach + // exception handling, while leaving the standard BSD signal handlers functional. + kern_return_t kr; + kr = task_set_exception_ports(mach_task_self(), + EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC, + MACH_PORT_NULL, + EXCEPTION_STATE_IDENTITY, + MACHINE_THREAD_STATE); + + assert(kr == KERN_SUCCESS, "could not set mach task signal handler"); +#endif + + if (libjsig_is_loaded) { + // Tell libjsig jvm finishes setting signal handlers + (*end_signal_setting)(); + } + + // We don't activate signal checker if libjsig is in place, we trust ourselves + // and if UserSignalHandler is installed all bets are off + if (CheckJNICalls) { + if (libjsig_is_loaded) { + tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); + check_signals = false; + } + if (AllowUserSignalHandlers) { + tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); + check_signals = false; + } + } + } +} + +#ifndef _ALLBSD_SOURCE +// This is the fastest way to get thread cpu time on Bsd. +// Returns cpu time (user+sys) for any thread, not only for current. +// POSIX compliant clocks are implemented in the kernels 2.6.16+. +// It might work on 2.6.10+ with a special kernel/glibc patch. +// For reference, please, see IEEE Std 1003.1-2004: +// http://www.unix.org/single_unix_specification + +jlong os::Bsd::fast_thread_cpu_time(clockid_t clockid) { + struct timespec tp; + int rc = os::Bsd::clock_gettime(clockid, &tp); + assert(rc == 0, "clock_gettime is expected to return 0 code"); + + return (tp.tv_sec * SEC_IN_NANOSECS) + tp.tv_nsec; +} +#endif + +///// +// glibc on Bsd platform uses non-documented flag +// to indicate, that some special sort of signal +// trampoline is used. +// We will never set this flag, and we should +// ignore this flag in our diagnostic +#ifdef SIGNIFICANT_SIGNAL_MASK +#undef SIGNIFICANT_SIGNAL_MASK +#endif +#define SIGNIFICANT_SIGNAL_MASK (~0x04000000) + +static const char* get_signal_handler_name(address handler, + char* buf, int buflen) { + int offset; + bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); + if (found) { + // skip directory names + const char *p1, *p2; + p1 = buf; + size_t len = strlen(os::file_separator()); + while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; + jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); + } else { + jio_snprintf(buf, buflen, PTR_FORMAT, handler); + } + return buf; +} + +static void print_signal_handler(outputStream* st, int sig, + char* buf, size_t buflen) { + struct sigaction sa; + + sigaction(sig, NULL, &sa); + + // See comment for SIGNIFICANT_SIGNAL_MASK define + sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; + + st->print("%s: ", os::exception_name(sig, buf, buflen)); + + address handler = (sa.sa_flags & SA_SIGINFO) + ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) + : CAST_FROM_FN_PTR(address, sa.sa_handler); + + if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { + st->print("SIG_DFL"); + } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { + st->print("SIG_IGN"); + } else { + st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); + } + + st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask); + + address rh = VMError::get_resetted_sighandler(sig); + // May be, handler was resetted by VMError? + if(rh != NULL) { + handler = rh; + sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; + } + + st->print(", sa_flags=" PTR32_FORMAT, sa.sa_flags); + + // Check: is it our handler? + if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || + handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { + // It is our signal handler + // check for flags, reset system-used one! + if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) { + st->print( + ", flags was changed from " PTR32_FORMAT ", consider using jsig library", + os::Bsd::get_our_sigflags(sig)); + } + } + st->cr(); +} + + +#define DO_SIGNAL_CHECK(sig) \ + if (!sigismember(&check_signal_done, sig)) \ + os::Bsd::check_signal_handler(sig) + +// This method is a periodic task to check for misbehaving JNI applications +// under CheckJNI, we can add any periodic checks here + +void os::run_periodic_checks() { + + if (check_signals == false) return; + + // SEGV and BUS if overridden could potentially prevent + // generation of hs*.log in the event of a crash, debugging + // such a case can be very challenging, so we absolutely + // check the following for a good measure: + DO_SIGNAL_CHECK(SIGSEGV); + DO_SIGNAL_CHECK(SIGILL); + DO_SIGNAL_CHECK(SIGFPE); + DO_SIGNAL_CHECK(SIGBUS); + DO_SIGNAL_CHECK(SIGPIPE); + DO_SIGNAL_CHECK(SIGXFSZ); + + + // ReduceSignalUsage allows the user to override these handlers + // see comments at the very top and jvm_solaris.h + if (!ReduceSignalUsage) { + DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); + DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); + DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); + DO_SIGNAL_CHECK(BREAK_SIGNAL); + } + + DO_SIGNAL_CHECK(SR_signum); + DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); +} + +typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); + +static os_sigaction_t os_sigaction = NULL; + +void os::Bsd::check_signal_handler(int sig) { + char buf[O_BUFLEN]; + address jvmHandler = NULL; + + + struct sigaction act; + if (os_sigaction == NULL) { + // only trust the default sigaction, in case it has been interposed + os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); + if (os_sigaction == NULL) return; + } + + os_sigaction(sig, (struct sigaction*)NULL, &act); + + + act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; + + address thisHandler = (act.sa_flags & SA_SIGINFO) + ? CAST_FROM_FN_PTR(address, act.sa_sigaction) + : CAST_FROM_FN_PTR(address, act.sa_handler) ; + + + switch(sig) { + case SIGSEGV: + case SIGBUS: + case SIGFPE: + case SIGPIPE: + case SIGILL: + case SIGXFSZ: + jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); + break; + + case SHUTDOWN1_SIGNAL: + case SHUTDOWN2_SIGNAL: + case SHUTDOWN3_SIGNAL: + case BREAK_SIGNAL: + jvmHandler = (address)user_handler(); + break; + + case INTERRUPT_SIGNAL: + jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); + break; + + default: + if (sig == SR_signum) { + jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); + } else { + return; + } + break; + } + + if (thisHandler != jvmHandler) { + tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); + tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); + tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); + // No need to check this sig any longer + sigaddset(&check_signal_done, sig); + } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) { + tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); + tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig)); + tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); + // No need to check this sig any longer + sigaddset(&check_signal_done, sig); + } + + // Dump all the signal + if (sigismember(&check_signal_done, sig)) { + print_signal_handlers(tty, buf, O_BUFLEN); + } +} + +extern void report_error(char* file_name, int line_no, char* title, char* format, ...); + +extern bool signal_name(int signo, char* buf, size_t len); + +const char* os::exception_name(int exception_code, char* buf, size_t size) { + if (0 < exception_code && exception_code <= SIGRTMAX) { + // signal + if (!signal_name(exception_code, buf, size)) { + jio_snprintf(buf, size, "SIG%d", exception_code); + } + return buf; + } else { + return NULL; + } +} + +// this is called _before_ the most of global arguments have been parsed +void os::init(void) { + char dummy; /* used to get a guess on initial stack address */ +// first_hrtime = gethrtime(); + + // With BsdThreads the JavaMain thread pid (primordial thread) + // is different than the pid of the java launcher thread. + // So, on Bsd, the launcher thread pid is passed to the VM + // via the sun.java.launcher.pid property. + // Use this property instead of getpid() if it was correctly passed. + // See bug 6351349. + pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); + + _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); + + clock_tics_per_sec = CLK_TCK; + + init_random(1234567); + + ThreadCritical::initialize(); + + Bsd::set_page_size(getpagesize()); + if (Bsd::page_size() == -1) { + fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)", + strerror(errno))); + } + init_page_sizes((size_t) Bsd::page_size()); + + Bsd::initialize_system_info(); + + // main_thread points to the aboriginal thread + Bsd::_main_thread = pthread_self(); + + Bsd::clock_init(); + initial_time_count = os::elapsed_counter(); + +#ifdef __APPLE__ + // XXXDARWIN + // Work around the unaligned VM callbacks in hotspot's + // sharedRuntime. The callbacks don't use SSE2 instructions, and work on + // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces + // alignment when doing symbol lookup. To work around this, we force early + // binding of all symbols now, thus binding when alignment is known-good. + _dyld_bind_fully_image_containing_address((const void *) &os::init); +#endif +} + +// To install functions for atexit system call +extern "C" { + static void perfMemory_exit_helper() { + perfMemory_exit(); + } +} + +// this is called _after_ the global arguments have been parsed +jint os::init_2(void) +{ +#ifndef _ALLBSD_SOURCE + Bsd::fast_thread_clock_init(); +#endif + + // Allocate a single page and mark it as readable for safepoint polling + address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); + guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" ); + + os::set_polling_page( polling_page ); + +#ifndef PRODUCT + if(Verbose && PrintMiscellaneous) + tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page); +#endif + + if (!UseMembar) { + address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); + guarantee( mem_serialize_page != NULL, "mmap Failed for memory serialize page"); + os::set_memory_serialize_page( mem_serialize_page ); + +#ifndef PRODUCT + if(Verbose && PrintMiscellaneous) + tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page); +#endif + } + + os::large_page_init(); + + // initialize suspend/resume support - must do this before signal_sets_init() + if (SR_initialize() != 0) { + perror("SR_initialize failed"); + return JNI_ERR; + } + + Bsd::signal_sets_init(); + Bsd::install_signal_handlers(); + + // Check minimum allowable stack size for thread creation and to initialize + // the java system classes, including StackOverflowError - depends on page + // size. Add a page for compiler2 recursion in main thread. + // Add in 2*BytesPerWord times page size to account for VM stack during + // class initialization depending on 32 or 64 bit VM. + os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed, + (size_t)(StackYellowPages+StackRedPages+StackShadowPages+ + 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size()); + + size_t threadStackSizeInBytes = ThreadStackSize * K; + if (threadStackSizeInBytes != 0 && + threadStackSizeInBytes < os::Bsd::min_stack_allowed) { + tty->print_cr("\nThe stack size specified is too small, " + "Specify at least %dk", + os::Bsd::min_stack_allowed/ K); + return JNI_ERR; + } + + // Make the stack size a multiple of the page size so that + // the yellow/red zones can be guarded. + JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, + vm_page_size())); + +#ifndef _ALLBSD_SOURCE + Bsd::capture_initial_stack(JavaThread::stack_size_at_create()); + + Bsd::libpthread_init(); + if (PrintMiscellaneous && (Verbose || WizardMode)) { + tty->print_cr("[HotSpot is running with %s, %s(%s)]\n", + Bsd::glibc_version(), Bsd::libpthread_version(), + Bsd::is_floating_stack() ? "floating stack" : "fixed stack"); + } + + if (UseNUMA) { + if (!Bsd::libnuma_init()) { + UseNUMA = false; + } else { + if ((Bsd::numa_max_node() < 1)) { + // There's only one node(they start from 0), disable NUMA. + UseNUMA = false; + } + } + // With SHM large pages we cannot uncommit a page, so there's not way + // we can make the adaptive lgrp chunk resizing work. If the user specified + // both UseNUMA and UseLargePages (or UseSHM) on the command line - warn and + // disable adaptive resizing. + if (UseNUMA && UseLargePages && UseSHM) { + if (!FLAG_IS_DEFAULT(UseNUMA)) { + if (FLAG_IS_DEFAULT(UseLargePages) && FLAG_IS_DEFAULT(UseSHM)) { + UseLargePages = false; + } else { + warning("UseNUMA is not fully compatible with SHM large pages, disabling adaptive resizing"); + UseAdaptiveSizePolicy = false; + UseAdaptiveNUMAChunkSizing = false; + } + } else { + UseNUMA = false; + } + } + if (!UseNUMA && ForceNUMA) { + UseNUMA = true; + } + } +#endif + + if (MaxFDLimit) { + // set the number of file descriptors to max. print out error + // if getrlimit/setrlimit fails but continue regardless. + struct rlimit nbr_files; + int status = getrlimit(RLIMIT_NOFILE, &nbr_files); + if (status != 0) { + if (PrintMiscellaneous && (Verbose || WizardMode)) + perror("os::init_2 getrlimit failed"); + } else { + nbr_files.rlim_cur = nbr_files.rlim_max; + +#ifdef __APPLE__ + // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if + // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must + // be used instead + nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur); +#endif + + status = setrlimit(RLIMIT_NOFILE, &nbr_files); + if (status != 0) { + if (PrintMiscellaneous && (Verbose || WizardMode)) + perror("os::init_2 setrlimit failed"); + } + } + } + +#ifndef _ALLBSD_SOURCE + // Initialize lock used to serialize thread creation (see os::create_thread) + Bsd::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false)); +#endif + + // at-exit methods are called in the reverse order of their registration. + // atexit functions are called on return from main or as a result of a + // call to exit(3C). There can be only 32 of these functions registered + // and atexit() does not set errno. + + if (PerfAllowAtExitRegistration) { + // only register atexit functions if PerfAllowAtExitRegistration is set. + // atexit functions can be delayed until process exit time, which + // can be problematic for embedded VM situations. Embedded VMs should + // call DestroyJavaVM() to assure that VM resources are released. + + // note: perfMemory_exit_helper atexit function may be removed in + // the future if the appropriate cleanup code can be added to the + // VM_Exit VMOperation's doit method. + if (atexit(perfMemory_exit_helper) != 0) { + warning("os::init2 atexit(perfMemory_exit_helper) failed"); + } + } + + // initialize thread priority policy + prio_init(); + + return JNI_OK; +} + +// this is called at the end of vm_initialization +void os::init_3(void) { } + +// Mark the polling page as unreadable +void os::make_polling_page_unreadable(void) { + if( !guard_memory((char*)_polling_page, Bsd::page_size()) ) + fatal("Could not disable polling page"); +}; + +// Mark the polling page as readable +void os::make_polling_page_readable(void) { + if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) { + fatal("Could not enable polling page"); + } +}; + +int os::active_processor_count() { +#ifdef _ALLBSD_SOURCE + return _processor_count; +#else + // Bsd doesn't yet have a (official) notion of processor sets, + // so just return the number of online processors. + int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN); + assert(online_cpus > 0 && online_cpus <= processor_count(), "sanity check"); + return online_cpus; +#endif +} + +bool os::distribute_processes(uint length, uint* distribution) { + // Not yet implemented. + return false; +} + +bool os::bind_to_processor(uint processor_id) { + // Not yet implemented. + return false; +} + +/// + +// Suspends the target using the signal mechanism and then grabs the PC before +// resuming the target. Used by the flat-profiler only +ExtendedPC os::get_thread_pc(Thread* thread) { + // Make sure that it is called by the watcher for the VMThread + assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); + assert(thread->is_VM_thread(), "Can only be called for VMThread"); + + ExtendedPC epc; + + OSThread* osthread = thread->osthread(); + if (do_suspend(osthread)) { + if (osthread->ucontext() != NULL) { + epc = os::Bsd::ucontext_get_pc(osthread->ucontext()); + } else { + // NULL context is unexpected, double-check this is the VMThread + guarantee(thread->is_VM_thread(), "can only be called for VMThread"); + } + do_resume(osthread); + } + // failure means pthread_kill failed for some reason - arguably this is + // a fatal problem, but such problems are ignored elsewhere + + return epc; +} + +int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime) +{ +#ifdef _ALLBSD_SOURCE + return pthread_cond_timedwait(_cond, _mutex, _abstime); +#else + if (is_NPTL()) { + return pthread_cond_timedwait(_cond, _mutex, _abstime); + } else { +#ifndef IA64 + // 6292965: BsdThreads pthread_cond_timedwait() resets FPU control + // word back to default 64bit precision if condvar is signaled. Java + // wants 53bit precision. Save and restore current value. + int fpu = get_fpu_control_word(); +#endif // IA64 + int status = pthread_cond_timedwait(_cond, _mutex, _abstime); +#ifndef IA64 + set_fpu_control_word(fpu); +#endif // IA64 + return status; + } +#endif +} + +//////////////////////////////////////////////////////////////////////////////// +// debug support + +static address same_page(address x, address y) { + int page_bits = -os::vm_page_size(); + if ((intptr_t(x) & page_bits) == (intptr_t(y) & page_bits)) + return x; + else if (x > y) + return (address)(intptr_t(y) | ~page_bits) + 1; + else + return (address)(intptr_t(y) & page_bits); +} + +bool os::find(address addr, outputStream* st) { + Dl_info dlinfo; + memset(&dlinfo, 0, sizeof(dlinfo)); + if (dladdr(addr, &dlinfo)) { + st->print(PTR_FORMAT ": ", addr); + if (dlinfo.dli_sname != NULL) { + st->print("%s+%#x", dlinfo.dli_sname, + addr - (intptr_t)dlinfo.dli_saddr); + } else if (dlinfo.dli_fname) { + st->print("", addr - (intptr_t)dlinfo.dli_fbase); + } else { + st->print(""); + } + if (dlinfo.dli_fname) { + st->print(" in %s", dlinfo.dli_fname); + } + if (dlinfo.dli_fbase) { + st->print(" at " PTR_FORMAT, dlinfo.dli_fbase); + } + st->cr(); + + if (Verbose) { + // decode some bytes around the PC + address begin = same_page(addr-40, addr); + address end = same_page(addr+40, addr); + address lowest = (address) dlinfo.dli_sname; + if (!lowest) lowest = (address) dlinfo.dli_fbase; + if (begin < lowest) begin = lowest; + Dl_info dlinfo2; + if (dladdr(end, &dlinfo2) && dlinfo2.dli_saddr != dlinfo.dli_saddr + && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) + end = (address) dlinfo2.dli_saddr; + Disassembler::decode(begin, end, st); + } + return true; + } + return false; +} + +//////////////////////////////////////////////////////////////////////////////// +// misc + +// This does not do anything on Bsd. This is basically a hook for being +// able to use structured exception handling (thread-local exception filters) +// on, e.g., Win32. +void +os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, + JavaCallArguments* args, Thread* thread) { + f(value, method, args, thread); +} + +void os::print_statistics() { +} + +int os::message_box(const char* title, const char* message) { + int i; + fdStream err(defaultStream::error_fd()); + for (i = 0; i < 78; i++) err.print_raw("="); + err.cr(); + err.print_raw_cr(title); + for (i = 0; i < 78; i++) err.print_raw("-"); + err.cr(); + err.print_raw_cr(message); + for (i = 0; i < 78; i++) err.print_raw("="); + err.cr(); + + char buf[16]; + // Prevent process from exiting upon "read error" without consuming all CPU + while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } + + return buf[0] == 'y' || buf[0] == 'Y'; +} + +int os::stat(const char *path, struct stat *sbuf) { + char pathbuf[MAX_PATH]; + if (strlen(path) > MAX_PATH - 1) { + errno = ENAMETOOLONG; + return -1; + } + os::native_path(strcpy(pathbuf, path)); + return ::stat(pathbuf, sbuf); +} + +bool os::check_heap(bool force) { + return true; +} + +int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) { + return ::vsnprintf(buf, count, format, args); +} + +// Is a (classpath) directory empty? +bool os::dir_is_empty(const char* path) { + DIR *dir = NULL; + struct dirent *ptr; + + dir = opendir(path); + if (dir == NULL) return true; + + /* Scan the directory */ + bool result = true; + char buf[sizeof(struct dirent) + MAX_PATH]; + while (result && (ptr = ::readdir(dir)) != NULL) { + if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { + result = false; + } + } + closedir(dir); + return result; +} + +// This code originates from JDK's sysOpen and open64_w +// from src/solaris/hpi/src/system_md.c + +#ifndef O_DELETE +#define O_DELETE 0x10000 +#endif + +// Open a file. Unlink the file immediately after open returns +// if the specified oflag has the O_DELETE flag set. +// O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c + +int os::open(const char *path, int oflag, int mode) { + + if (strlen(path) > MAX_PATH - 1) { + errno = ENAMETOOLONG; + return -1; + } + int fd; + int o_delete = (oflag & O_DELETE); + oflag = oflag & ~O_DELETE; + + fd = ::open(path, oflag, mode); + if (fd == -1) return -1; + + //If the open succeeded, the file might still be a directory + { + struct stat buf; + int ret = ::fstat(fd, &buf); + int st_mode = buf.st_mode; + + if (ret != -1) { + if ((st_mode & S_IFMT) == S_IFDIR) { + errno = EISDIR; + ::close(fd); + return -1; + } + } else { + ::close(fd); + return -1; + } + } + + /* + * All file descriptors that are opened in the JVM and not + * specifically destined for a subprocess should have the + * close-on-exec flag set. If we don't set it, then careless 3rd + * party native code might fork and exec without closing all + * appropriate file descriptors (e.g. as we do in closeDescriptors in + * UNIXProcess.c), and this in turn might: + * + * - cause end-of-file to fail to be detected on some file + * descriptors, resulting in mysterious hangs, or + * + * - might cause an fopen in the subprocess to fail on a system + * suffering from bug 1085341. + * + * (Yes, the default setting of the close-on-exec flag is a Unix + * design flaw) + * + * See: + * 1085341: 32-bit stdio routines should support file descriptors >255 + * 4843136: (process) pipe file descriptor from Runtime.exec not being closed + * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 + */ +#ifdef FD_CLOEXEC + { + int flags = ::fcntl(fd, F_GETFD); + if (flags != -1) + ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); + } +#endif + + if (o_delete != 0) { + ::unlink(path); + } + return fd; +} + + +// create binary file, rewriting existing file if required +int os::create_binary_file(const char* path, bool rewrite_existing) { + int oflags = O_WRONLY | O_CREAT; + if (!rewrite_existing) { + oflags |= O_EXCL; + } + return ::open(path, oflags, S_IREAD | S_IWRITE); +} + +// return current position of file pointer +jlong os::current_file_offset(int fd) { + return (jlong)::lseek(fd, (off_t)0, SEEK_CUR); +} + +// move file pointer to the specified offset +jlong os::seek_to_file_offset(int fd, jlong offset) { + return (jlong)::lseek(fd, (off_t)offset, SEEK_SET); +} + +// This code originates from JDK's sysAvailable +// from src/solaris/hpi/src/native_threads/src/sys_api_td.c + +int os::available(int fd, jlong *bytes) { + jlong cur, end; + int mode; + struct stat buf; + + if (::fstat(fd, &buf) >= 0) { + mode = buf.st_mode; + if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { + /* + * XXX: is the following call interruptible? If so, this might + * need to go through the INTERRUPT_IO() wrapper as for other + * blocking, interruptible calls in this file. + */ + int n; + if (::ioctl(fd, FIONREAD, &n) >= 0) { + *bytes = n; + return 1; + } + } + } + if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) { + return 0; + } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) { + return 0; + } else if (::lseek(fd, cur, SEEK_SET) == -1) { + return 0; + } + *bytes = end - cur; + return 1; +} + +int os::socket_available(int fd, jint *pbytes) { + if (fd < 0) + return OS_OK; + + int ret; + + RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret); + + //%% note ioctl can return 0 when successful, JVM_SocketAvailable + // is expected to return 0 on failure and 1 on success to the jdk. + + return (ret == OS_ERR) ? 0 : 1; +} + +// Map a block of memory. +char* os::map_memory(int fd, const char* file_name, size_t file_offset, + char *addr, size_t bytes, bool read_only, + bool allow_exec) { + int prot; + int flags; + + if (read_only) { + prot = PROT_READ; + flags = MAP_SHARED; + } else { + prot = PROT_READ | PROT_WRITE; + flags = MAP_PRIVATE; + } + + if (allow_exec) { + prot |= PROT_EXEC; + } + + if (addr != NULL) { + flags |= MAP_FIXED; + } + + char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, + fd, file_offset); + if (mapped_address == MAP_FAILED) { + return NULL; + } + return mapped_address; +} + + +// Remap a block of memory. +char* os::remap_memory(int fd, const char* file_name, size_t file_offset, + char *addr, size_t bytes, bool read_only, + bool allow_exec) { + // same as map_memory() on this OS + return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, + allow_exec); +} + + +// Unmap a block of memory. +bool os::unmap_memory(char* addr, size_t bytes) { + return munmap(addr, bytes) == 0; +} + +#ifndef _ALLBSD_SOURCE +static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time); + +static clockid_t thread_cpu_clockid(Thread* thread) { + pthread_t tid = thread->osthread()->pthread_id(); + clockid_t clockid; + + // Get thread clockid + int rc = os::Bsd::pthread_getcpuclockid(tid, &clockid); + assert(rc == 0, "pthread_getcpuclockid is expected to return 0 code"); + return clockid; +} +#endif + +// current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) +// are used by JVM M&M and JVMTI to get user+sys or user CPU time +// of a thread. +// +// current_thread_cpu_time() and thread_cpu_time(Thread*) returns +// the fast estimate available on the platform. + +jlong os::current_thread_cpu_time() { +#ifdef __APPLE__ + return os::thread_cpu_time(Thread::current(), true /* user + sys */); +#elif !defined(_ALLBSD_SOURCE) + if (os::Bsd::supports_fast_thread_cpu_time()) { + return os::Bsd::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); + } else { + // return user + sys since the cost is the same + return slow_thread_cpu_time(Thread::current(), true /* user + sys */); + } +#endif +} + +jlong os::thread_cpu_time(Thread* thread) { +#ifndef _ALLBSD_SOURCE + // consistent with what current_thread_cpu_time() returns + if (os::Bsd::supports_fast_thread_cpu_time()) { + return os::Bsd::fast_thread_cpu_time(thread_cpu_clockid(thread)); + } else { + return slow_thread_cpu_time(thread, true /* user + sys */); + } +#endif +} + +jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { +#ifdef __APPLE__ + return os::thread_cpu_time(Thread::current(), user_sys_cpu_time); +#elif !defined(_ALLBSD_SOURCE) + if (user_sys_cpu_time && os::Bsd::supports_fast_thread_cpu_time()) { + return os::Bsd::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); + } else { + return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time); + } +#endif +} + +jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { +#ifdef __APPLE__ + struct thread_basic_info tinfo; + mach_msg_type_number_t tcount = THREAD_INFO_MAX; + kern_return_t kr; + mach_port_t mach_thread; + + mach_thread = pthread_mach_thread_np(thread->osthread()->thread_id()); + kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount); + if (kr != KERN_SUCCESS) + return -1; + + if (user_sys_cpu_time) { + jlong nanos; + nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000; + nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000; + return nanos; + } else { + return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000); + } +#elif !defined(_ALLBSD_SOURCE) + if (user_sys_cpu_time && os::Bsd::supports_fast_thread_cpu_time()) { + return os::Bsd::fast_thread_cpu_time(thread_cpu_clockid(thread)); + } else { + return slow_thread_cpu_time(thread, user_sys_cpu_time); + } +#endif +} + +#ifndef _ALLBSD_SOURCE +// +// -1 on error. +// + +static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { + static bool proc_pid_cpu_avail = true; + static bool proc_task_unchecked = true; + static const char *proc_stat_path = "/proc/%d/stat"; + pid_t tid = thread->osthread()->thread_id(); + int i; + char *s; + char stat[2048]; + int statlen; + char proc_name[64]; + int count; + long sys_time, user_time; + char string[64]; + char cdummy; + int idummy; + long ldummy; + FILE *fp; + + // We first try accessing /proc//cpu since this is faster to + // process. If this file is not present (bsd kernels 2.5 and above) + // then we open /proc//stat. + if ( proc_pid_cpu_avail ) { + sprintf(proc_name, "/proc/%d/cpu", tid); + fp = fopen(proc_name, "r"); + if ( fp != NULL ) { + count = fscanf( fp, "%s %lu %lu\n", string, &user_time, &sys_time); + fclose(fp); + if ( count != 3 ) return -1; + + if (user_sys_cpu_time) { + return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); + } else { + return (jlong)user_time * (1000000000 / clock_tics_per_sec); + } + } + else proc_pid_cpu_avail = false; + } + + // The /proc//stat aggregates per-process usage on + // new Bsd kernels 2.6+ where NPTL is supported. + // The /proc/self/task//stat still has the per-thread usage. + // See bug 6328462. + // There can be no directory /proc/self/task on kernels 2.4 with NPTL + // and possibly in some other cases, so we check its availability. + if (proc_task_unchecked && os::Bsd::is_NPTL()) { + // This is executed only once + proc_task_unchecked = false; + fp = fopen("/proc/self/task", "r"); + if (fp != NULL) { + proc_stat_path = "/proc/self/task/%d/stat"; + fclose(fp); + } + } + + sprintf(proc_name, proc_stat_path, tid); + fp = fopen(proc_name, "r"); + if ( fp == NULL ) return -1; + statlen = fread(stat, 1, 2047, fp); + stat[statlen] = '\0'; + fclose(fp); + + // Skip pid and the command string. Note that we could be dealing with + // weird command names, e.g. user could decide to rename java launcher + // to "java 1.4.2 :)", then the stat file would look like + // 1234 (java 1.4.2 :)) R ... ... + // We don't really need to know the command string, just find the last + // occurrence of ")" and then start parsing from there. See bug 4726580. + s = strrchr(stat, ')'); + i = 0; + if (s == NULL ) return -1; + + // Skip blank chars + do s++; while (isspace(*s)); + + count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu", + &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy, + &ldummy, &ldummy, &ldummy, &ldummy, &ldummy, + &user_time, &sys_time); + if ( count != 13 ) return -1; + if (user_sys_cpu_time) { + return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); + } else { + return (jlong)user_time * (1000000000 / clock_tics_per_sec); + } +} +#endif + +void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { + info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits + info_ptr->may_skip_backward = false; // elapsed time not wall time + info_ptr->may_skip_forward = false; // elapsed time not wall time + info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned +} + +void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { + info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits + info_ptr->may_skip_backward = false; // elapsed time not wall time + info_ptr->may_skip_forward = false; // elapsed time not wall time + info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned +} + +bool os::is_thread_cpu_time_supported() { +#ifdef __APPLE__ + return true; +#elif defined(_ALLBSD_SOURCE) + return false; +#else + return true; +#endif +} + +// System loadavg support. Returns -1 if load average cannot be obtained. +// Bsd doesn't yet have a (official) notion of processor sets, +// so just return the system wide load average. +int os::loadavg(double loadavg[], int nelem) { + return ::getloadavg(loadavg, nelem); +} + +void os::pause() { + char filename[MAX_PATH]; + if (PauseAtStartupFile && PauseAtStartupFile[0]) { + jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); + } else { + jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); + } + + int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); + if (fd != -1) { + struct stat buf; + ::close(fd); + while (::stat(filename, &buf) == 0) { + (void)::poll(NULL, 0, 100); + } + } else { + jio_fprintf(stderr, + "Could not open pause file '%s', continuing immediately.\n", filename); + } +} + + +// Refer to the comments in os_solaris.cpp park-unpark. +// +// Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can +// hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. +// For specifics regarding the bug see GLIBC BUGID 261237 : +// http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. +// Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future +// will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar +// is used. (The simple C test-case provided in the GLIBC bug report manifests the +// hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() +// and monitorenter when we're using 1-0 locking. All those operations may result in +// calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version +// of libpthread avoids the problem, but isn't practical. +// +// Possible remedies: +// +// 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. +// This is palliative and probabilistic, however. If the thread is preempted +// between the call to compute_abstime() and pthread_cond_timedwait(), more +// than the minimum period may have passed, and the abstime may be stale (in the +// past) resultin in a hang. Using this technique reduces the odds of a hang +// but the JVM is still vulnerable, particularly on heavily loaded systems. +// +// 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead +// of the usual flag-condvar-mutex idiom. The write side of the pipe is set +// NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) +// reduces to poll()+read(). This works well, but consumes 2 FDs per extant +// thread. +// +// 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread +// that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing +// a timeout request to the chron thread and then blocking via pthread_cond_wait(). +// This also works well. In fact it avoids kernel-level scalability impediments +// on certain platforms that don't handle lots of active pthread_cond_timedwait() +// timers in a graceful fashion. +// +// 4. When the abstime value is in the past it appears that control returns +// correctly from pthread_cond_timedwait(), but the condvar is left corrupt. +// Subsequent timedwait/wait calls may hang indefinitely. Given that, we +// can avoid the problem by reinitializing the condvar -- by cond_destroy() +// followed by cond_init() -- after all calls to pthread_cond_timedwait(). +// It may be possible to avoid reinitialization by checking the return +// value from pthread_cond_timedwait(). In addition to reinitializing the +// condvar we must establish the invariant that cond_signal() is only called +// within critical sections protected by the adjunct mutex. This prevents +// cond_signal() from "seeing" a condvar that's in the midst of being +// reinitialized or that is corrupt. Sadly, this invariant obviates the +// desirable signal-after-unlock optimization that avoids futile context switching. +// +// I'm also concerned that some versions of NTPL might allocate an auxilliary +// structure when a condvar is used or initialized. cond_destroy() would +// release the helper structure. Our reinitialize-after-timedwait fix +// put excessive stress on malloc/free and locks protecting the c-heap. +// +// We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. +// It may be possible to refine (4) by checking the kernel and NTPL verisons +// and only enabling the work-around for vulnerable environments. + +// utility to compute the abstime argument to timedwait: +// millis is the relative timeout time +// abstime will be the absolute timeout time +// TODO: replace compute_abstime() with unpackTime() + +static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) { + if (millis < 0) millis = 0; + struct timeval now; + int status = gettimeofday(&now, NULL); + assert(status == 0, "gettimeofday"); + jlong seconds = millis / 1000; + millis %= 1000; + if (seconds > 50000000) { // see man cond_timedwait(3T) + seconds = 50000000; + } + abstime->tv_sec = now.tv_sec + seconds; + long usec = now.tv_usec + millis * 1000; + if (usec >= 1000000) { + abstime->tv_sec += 1; + usec -= 1000000; + } + abstime->tv_nsec = usec * 1000; + return abstime; +} + + +// Test-and-clear _Event, always leaves _Event set to 0, returns immediately. +// Conceptually TryPark() should be equivalent to park(0). + +int os::PlatformEvent::TryPark() { + for (;;) { + const int v = _Event ; + guarantee ((v == 0) || (v == 1), "invariant") ; + if (Atomic::cmpxchg (0, &_Event, v) == v) return v ; + } +} + +void os::PlatformEvent::park() { // AKA "down()" + // Invariant: Only the thread associated with the Event/PlatformEvent + // may call park(). + // TODO: assert that _Assoc != NULL or _Assoc == Self + int v ; + for (;;) { + v = _Event ; + if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; + } + guarantee (v >= 0, "invariant") ; + if (v == 0) { + // Do this the hard way by blocking ... + int status = pthread_mutex_lock(_mutex); + assert_status(status == 0, status, "mutex_lock"); + guarantee (_nParked == 0, "invariant") ; + ++ _nParked ; + while (_Event < 0) { + status = pthread_cond_wait(_cond, _mutex); + // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... + // Treat this the same as if the wait was interrupted + if (status == ETIMEDOUT) { status = EINTR; } + assert_status(status == 0 || status == EINTR, status, "cond_wait"); + } + -- _nParked ; + + // In theory we could move the ST of 0 into _Event past the unlock(), + // but then we'd need a MEMBAR after the ST. + _Event = 0 ; + status = pthread_mutex_unlock(_mutex); + assert_status(status == 0, status, "mutex_unlock"); + } + guarantee (_Event >= 0, "invariant") ; +} + +int os::PlatformEvent::park(jlong millis) { + guarantee (_nParked == 0, "invariant") ; + + int v ; + for (;;) { + v = _Event ; + if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; + } + guarantee (v >= 0, "invariant") ; + if (v != 0) return OS_OK ; + + // We do this the hard way, by blocking the thread. + // Consider enforcing a minimum timeout value. + struct timespec abst; + compute_abstime(&abst, millis); + + int ret = OS_TIMEOUT; + int status = pthread_mutex_lock(_mutex); + assert_status(status == 0, status, "mutex_lock"); + guarantee (_nParked == 0, "invariant") ; + ++_nParked ; + + // Object.wait(timo) will return because of + // (a) notification + // (b) timeout + // (c) thread.interrupt + // + // Thread.interrupt and object.notify{All} both call Event::set. + // That is, we treat thread.interrupt as a special case of notification. + // The underlying Solaris implementation, cond_timedwait, admits + // spurious/premature wakeups, but the JLS/JVM spec prevents the + // JVM from making those visible to Java code. As such, we must + // filter out spurious wakeups. We assume all ETIME returns are valid. + // + // TODO: properly differentiate simultaneous notify+interrupt. + // In that case, we should propagate the notify to another waiter. + + while (_Event < 0) { + status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst); + if (status != 0 && WorkAroundNPTLTimedWaitHang) { + pthread_cond_destroy (_cond); + pthread_cond_init (_cond, NULL) ; + } + assert_status(status == 0 || status == EINTR || + status == ETIMEDOUT, + status, "cond_timedwait"); + if (!FilterSpuriousWakeups) break ; // previous semantics + if (status == ETIMEDOUT) break ; + // We consume and ignore EINTR and spurious wakeups. + } + --_nParked ; + if (_Event >= 0) { + ret = OS_OK; + } + _Event = 0 ; + status = pthread_mutex_unlock(_mutex); + assert_status(status == 0, status, "mutex_unlock"); + assert (_nParked == 0, "invariant") ; + return ret; +} + +void os::PlatformEvent::unpark() { + int v, AnyWaiters ; + for (;;) { + v = _Event ; + if (v > 0) { + // The LD of _Event could have reordered or be satisfied + // by a read-aside from this processor's write buffer. + // To avoid problems execute a barrier and then + // ratify the value. + OrderAccess::fence() ; + if (_Event == v) return ; + continue ; + } + if (Atomic::cmpxchg (v+1, &_Event, v) == v) break ; + } + if (v < 0) { + // Wait for the thread associated with the event to vacate + int status = pthread_mutex_lock(_mutex); + assert_status(status == 0, status, "mutex_lock"); + AnyWaiters = _nParked ; + assert (AnyWaiters == 0 || AnyWaiters == 1, "invariant") ; + if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { + AnyWaiters = 0 ; + pthread_cond_signal (_cond); + } + status = pthread_mutex_unlock(_mutex); + assert_status(status == 0, status, "mutex_unlock"); + if (AnyWaiters != 0) { + status = pthread_cond_signal(_cond); + assert_status(status == 0, status, "cond_signal"); + } + } + + // Note that we signal() _after dropping the lock for "immortal" Events. + // This is safe and avoids a common class of futile wakeups. In rare + // circumstances this can cause a thread to return prematurely from + // cond_{timed}wait() but the spurious wakeup is benign and the victim will + // simply re-test the condition and re-park itself. +} + + +// JSR166 +// ------------------------------------------------------- + +/* + * The solaris and bsd implementations of park/unpark are fairly + * conservative for now, but can be improved. They currently use a + * mutex/condvar pair, plus a a count. + * Park decrements count if > 0, else does a condvar wait. Unpark + * sets count to 1 and signals condvar. Only one thread ever waits + * on the condvar. Contention seen when trying to park implies that someone + * is unparking you, so don't wait. And spurious returns are fine, so there + * is no need to track notifications. + */ + + +#define NANOSECS_PER_SEC 1000000000 +#define NANOSECS_PER_MILLISEC 1000000 +#define MAX_SECS 100000000 +/* + * This code is common to bsd and solaris and will be moved to a + * common place in dolphin. + * + * The passed in time value is either a relative time in nanoseconds + * or an absolute time in milliseconds. Either way it has to be unpacked + * into suitable seconds and nanoseconds components and stored in the + * given timespec structure. + * Given time is a 64-bit value and the time_t used in the timespec is only + * a signed-32-bit value (except on 64-bit Bsd) we have to watch for + * overflow if times way in the future are given. Further on Solaris versions + * prior to 10 there is a restriction (see cond_timedwait) that the specified + * number of seconds, in abstime, is less than current_time + 100,000,000. + * As it will be 28 years before "now + 100000000" will overflow we can + * ignore overflow and just impose a hard-limit on seconds using the value + * of "now + 100,000,000". This places a limit on the timeout of about 3.17 + * years from "now". + */ + +static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) { + assert (time > 0, "convertTime"); + + struct timeval now; + int status = gettimeofday(&now, NULL); + assert(status == 0, "gettimeofday"); + + time_t max_secs = now.tv_sec + MAX_SECS; + + if (isAbsolute) { + jlong secs = time / 1000; + if (secs > max_secs) { + absTime->tv_sec = max_secs; + } + else { + absTime->tv_sec = secs; + } + absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; + } + else { + jlong secs = time / NANOSECS_PER_SEC; + if (secs >= MAX_SECS) { + absTime->tv_sec = max_secs; + absTime->tv_nsec = 0; + } + else { + absTime->tv_sec = now.tv_sec + secs; + absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; + if (absTime->tv_nsec >= NANOSECS_PER_SEC) { + absTime->tv_nsec -= NANOSECS_PER_SEC; + ++absTime->tv_sec; // note: this must be <= max_secs + } + } + } + assert(absTime->tv_sec >= 0, "tv_sec < 0"); + assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); + assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); + assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); +} + +void Parker::park(bool isAbsolute, jlong time) { + // Optional fast-path check: + // Return immediately if a permit is available. + if (_counter > 0) { + _counter = 0 ; + OrderAccess::fence(); + return ; + } + + Thread* thread = Thread::current(); + assert(thread->is_Java_thread(), "Must be JavaThread"); + JavaThread *jt = (JavaThread *)thread; + + // Optional optimization -- avoid state transitions if there's an interrupt pending. + // Check interrupt before trying to wait + if (Thread::is_interrupted(thread, false)) { + return; + } + + // Next, demultiplex/decode time arguments + struct timespec absTime; + if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all + return; + } + if (time > 0) { + unpackTime(&absTime, isAbsolute, time); + } + + + // Enter safepoint region + // Beware of deadlocks such as 6317397. + // The per-thread Parker:: mutex is a classic leaf-lock. + // In particular a thread must never block on the Threads_lock while + // holding the Parker:: mutex. If safepoints are pending both the + // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. + ThreadBlockInVM tbivm(jt); + + // Don't wait if cannot get lock since interference arises from + // unblocking. Also. check interrupt before trying wait + if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { + return; + } + + int status ; + if (_counter > 0) { // no wait needed + _counter = 0; + status = pthread_mutex_unlock(_mutex); + assert (status == 0, "invariant") ; + OrderAccess::fence(); + return; + } + +#ifdef ASSERT + // Don't catch signals while blocked; let the running threads have the signals. + // (This allows a debugger to break into the running thread.) + sigset_t oldsigs; + sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals(); + pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); +#endif + + OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); + jt->set_suspend_equivalent(); + // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() + + if (time == 0) { + status = pthread_cond_wait (_cond, _mutex) ; + } else { + status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ; + if (status != 0 && WorkAroundNPTLTimedWaitHang) { + pthread_cond_destroy (_cond) ; + pthread_cond_init (_cond, NULL); + } + } + assert_status(status == 0 || status == EINTR || + status == ETIMEDOUT, + status, "cond_timedwait"); + +#ifdef ASSERT + pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); +#endif + + _counter = 0 ; + status = pthread_mutex_unlock(_mutex) ; + assert_status(status == 0, status, "invariant") ; + // If externally suspended while waiting, re-suspend + if (jt->handle_special_suspend_equivalent_condition()) { + jt->java_suspend_self(); + } + + OrderAccess::fence(); +} + +void Parker::unpark() { + int s, status ; + status = pthread_mutex_lock(_mutex); + assert (status == 0, "invariant") ; + s = _counter; + _counter = 1; + if (s < 1) { + if (WorkAroundNPTLTimedWaitHang) { + status = pthread_cond_signal (_cond) ; + assert (status == 0, "invariant") ; + status = pthread_mutex_unlock(_mutex); + assert (status == 0, "invariant") ; + } else { + status = pthread_mutex_unlock(_mutex); + assert (status == 0, "invariant") ; + status = pthread_cond_signal (_cond) ; + assert (status == 0, "invariant") ; + } + } else { + pthread_mutex_unlock(_mutex); + assert (status == 0, "invariant") ; + } +} + + +/* Darwin has no "environ" in a dynamic library. */ +#ifdef __APPLE__ +#include +#define environ (*_NSGetEnviron()) +#else +extern char** environ; +#endif + +// Run the specified command in a separate process. Return its exit value, +// or -1 on failure (e.g. can't fork a new process). +// Unlike system(), this function can be called from signal handler. It +// doesn't block SIGINT et al. +int os::fork_and_exec(char* cmd) { + const char * argv[4] = {"sh", "-c", cmd, NULL}; + + // fork() in BsdThreads/NPTL is not async-safe. It needs to run + // pthread_atfork handlers and reset pthread library. All we need is a + // separate process to execve. Make a direct syscall to fork process. + // On IA64 there's no fork syscall, we have to use fork() and hope for + // the best... + pid_t pid = fork(); + + if (pid < 0) { + // fork failed + return -1; + + } else if (pid == 0) { + // child process + + // execve() in BsdThreads will call pthread_kill_other_threads_np() + // first to kill every thread on the thread list. Because this list is + // not reset by fork() (see notes above), execve() will instead kill + // every thread in the parent process. We know this is the only thread + // in the new process, so make a system call directly. + // IA64 should use normal execve() from glibc to match the glibc fork() + // above. + execve("/bin/sh", (char* const*)argv, environ); + + // execve failed + _exit(-1); + + } else { + // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't + // care about the actual exit code, for now. + + int status; + + // Wait for the child process to exit. This returns immediately if + // the child has already exited. */ + while (waitpid(pid, &status, 0) < 0) { + switch (errno) { + case ECHILD: return 0; + case EINTR: break; + default: return -1; + } + } + + if (WIFEXITED(status)) { + // The child exited normally; get its exit code. + return WEXITSTATUS(status); + } else if (WIFSIGNALED(status)) { + // The child exited because of a signal + // The best value to return is 0x80 + signal number, + // because that is what all Unix shells do, and because + // it allows callers to distinguish between process exit and + // process death by signal. + return 0x80 + WTERMSIG(status); + } else { + // Unknown exit code; pass it through + return status; + } + } +} + +// is_headless_jre() +// +// Test for the existence of libmawt in motif21 or xawt directories +// in order to report if we are running in a headless jre +// +bool os::is_headless_jre() { + struct stat statbuf; + char buf[MAXPATHLEN]; + char libmawtpath[MAXPATHLEN]; + const char *xawtstr = "/xawt/libmawt.so"; + const char *motifstr = "/motif21/libmawt.so"; + char *p; + + // Get path to libjvm.so + os::jvm_path(buf, sizeof(buf)); + + // Get rid of libjvm.so + p = strrchr(buf, '/'); + if (p == NULL) return false; + else *p = '\0'; + + // Get rid of client or server + p = strrchr(buf, '/'); + if (p == NULL) return false; + else *p = '\0'; + + // check xawt/libmawt.so + strcpy(libmawtpath, buf); + strcat(libmawtpath, xawtstr); + if (::stat(libmawtpath, &statbuf) == 0) return false; + + // check motif21/libmawt.so + strcpy(libmawtpath, buf); + strcat(libmawtpath, motifstr); + if (::stat(libmawtpath, &statbuf) == 0) return false; + + return true; +}