/* * Copyright (c) 1999, 2018, 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 "jvm.h" #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 "compiler/disassembler.hpp" #include "interpreter/interpreter.hpp" #include "logging/log.hpp" #include "memory/allocation.inline.hpp" #include "memory/filemap.hpp" #include "oops/oop.inline.hpp" #include "os_linux.inline.hpp" #include "os_share_linux.hpp" #include "osContainer_linux.hpp" #include "prims/jniFastGetField.hpp" #include "prims/jvm_misc.hpp" #include "runtime/arguments.hpp" #include "runtime/atomic.hpp" #include "runtime/extendedPC.hpp" #include "runtime/globals.hpp" #include "runtime/interfaceSupport.inline.hpp" #include "runtime/init.hpp" #include "runtime/java.hpp" #include "runtime/javaCalls.hpp" #include "runtime/mutexLocker.hpp" #include "runtime/objectMonitor.hpp" #include "runtime/orderAccess.hpp" #include "runtime/osThread.hpp" #include "runtime/perfMemory.hpp" #include "runtime/sharedRuntime.hpp" #include "runtime/statSampler.hpp" #include "runtime/stubRoutines.hpp" #include "runtime/thread.inline.hpp" #include "runtime/threadCritical.hpp" #include "runtime/threadSMR.hpp" #include "runtime/timer.hpp" #include "semaphore_posix.hpp" #include "services/attachListener.hpp" #include "services/memTracker.hpp" #include "services/runtimeService.hpp" #include "utilities/align.hpp" #include "utilities/decoder.hpp" #include "utilities/defaultStream.hpp" #include "utilities/events.hpp" #include "utilities/elfFile.hpp" #include "utilities/growableArray.hpp" #include "utilities/macros.hpp" #include "utilities/vmError.hpp" // 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 #ifndef _GNU_SOURCE #define _GNU_SOURCE #include #undef _GNU_SOURCE #else #include #endif // if RUSAGE_THREAD for getrusage() has not been defined, do it here. The code calling // getrusage() is prepared to handle the associated failure. #ifndef RUSAGE_THREAD #define RUSAGE_THREAD (1) /* only the calling thread */ #endif #define MAX_PATH (2 * K) #define MAX_SECS 100000000 // for timer info max values which include all bits #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) #define LARGEPAGES_BIT (1 << 6) #define DAX_SHARED_BIT (1 << 8) //////////////////////////////////////////////////////////////////////////////// // 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; int (*os::Linux::_pthread_setname_np)(pthread_t, const char*) = NULL; Mutex* os::Linux::_createThread_lock = NULL; pthread_t os::Linux::_main_thread; int os::Linux::_page_size = -1; bool os::Linux::_supports_fast_thread_cpu_time = false; uint32_t os::Linux::_os_version = 0; 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; // If the VM might have been created on the primordial thread, we need to resolve the // primordial thread stack bounds and check if the current thread might be the // primordial thread in places. If we know that the primordial thread is never used, // such as when the VM was created by one of the standard java launchers, we can // avoid this static bool suppress_primordial_thread_resolution = false; // For diagnostics to print a message once. see run_periodic_checks static sigset_t check_signal_done; static bool check_signals = true; // 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(); julong os::available_memory() { return Linux::available_memory(); } julong os::Linux::available_memory() { // values in struct sysinfo are "unsigned long" struct sysinfo si; julong avail_mem; if (OSContainer::is_containerized()) { jlong mem_limit, mem_usage; if ((mem_limit = OSContainer::memory_limit_in_bytes()) < 1) { log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value", mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit); } if (mem_limit > 0 && (mem_usage = OSContainer::memory_usage_in_bytes()) < 1) { log_debug(os, container)("container memory usage failed: " JLONG_FORMAT ", using host value", mem_usage); } if (mem_limit > 0 && mem_usage > 0 ) { avail_mem = mem_limit > mem_usage ? (julong)mem_limit - (julong)mem_usage : 0; log_trace(os)("available container memory: " JULONG_FORMAT, avail_mem); return avail_mem; } } sysinfo(&si); avail_mem = (julong)si.freeram * si.mem_unit; log_trace(os)("available memory: " JULONG_FORMAT, avail_mem); return avail_mem; } julong os::physical_memory() { jlong phys_mem = 0; if (OSContainer::is_containerized()) { jlong mem_limit; if ((mem_limit = OSContainer::memory_limit_in_bytes()) > 0) { log_trace(os)("total container memory: " JLONG_FORMAT, mem_limit); return mem_limit; } log_debug(os, container)("container memory limit %s: " JLONG_FORMAT ", using host value", mem_limit == OSCONTAINER_ERROR ? "failed" : "unlimited", mem_limit); } phys_mem = Linux::physical_memory(); log_trace(os)("total system memory: " JLONG_FORMAT, phys_mem); return phys_mem; } // 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 #else #ifdef __i386__ #define SYS_gettid 224 #else #ifdef __amd64__ #define SYS_gettid 186 #else #ifdef __sparc__ #define SYS_gettid 143 #else #error define gettid for the arch #endif #endif #endif #endif #endif // pid_t gettid() // // Returns the kernel thread id of the currently running thread. Kernel // thread id is used to access /proc. pid_t os::Linux::gettid() { int rslt = syscall(SYS_gettid); assert(rslt != -1, "must be."); // old linuxthreads implementation? 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() { // The next steps are taken in the product version: // // Obtain the JAVA_HOME value from the location of libjvm.so. // This library should be located at: // /lib/{client|server}/libjvm.so. // // If "/jre/lib/" appears at the right place in the path, then we // assume libjvm.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.so" to this path so // it looks like libjvm.so is installed there // /jre/lib//hotspot/libjvm.so. // // Otherwise exit. // // Important note: if the location of libjvm.so changes this // code needs to be changed accordingly. // 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(PPC64) || defined(S390) #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib" #else #define DEFAULT_LIBPATH "/lib:/usr/lib" #endif // Base path of extensions installed on the system. #define SYS_EXT_DIR "/usr/java/packages" #define EXTENSIONS_DIR "/lib/ext" // Buffer that fits several sprintfs. // Note that the space for the colon and the trailing null are provided // by the nulls included by the sizeof operator. const size_t bufsize = MAX2((size_t)MAXPATHLEN, // For dll_dir & friends. (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); // sysclasspath, java_home, dll_dir { char *pslash; os::jvm_path(buf, bufsize); // Found the full path to libjvm.so. // Now cut the path to /jre if we can. pslash = strrchr(buf, '/'); if (pslash != NULL) { *pslash = '\0'; // Get rid of /libjvm.so. } pslash = strrchr(buf, '/'); if (pslash != NULL) { *pslash = '\0'; // Get rid of /{client|server|hotspot}. } Arguments::set_dll_dir(buf); if (pslash != NULL) { pslash = strrchr(buf, '/'); if (pslash != NULL) { *pslash = '\0'; // Get rid of /lib. } } Arguments::set_java_home(buf); set_boot_path('/', ':'); } // 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. { // Get the user setting of LD_LIBRARY_PATH, and prepended it. It // should always exist (until the legacy problem cited above is // addressed). const char *v = ::getenv("LD_LIBRARY_PATH"); const char *v_colon = ":"; if (v == NULL) { v = ""; v_colon = ""; } // That's +1 for the colon and +1 for the trailing '\0'. char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, strlen(v) + 1 + sizeof(SYS_EXT_DIR) + sizeof("/lib/") + sizeof(DEFAULT_LIBPATH) + 1, mtInternal); sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib:" DEFAULT_LIBPATH, v, v_colon); Arguments::set_library_path(ld_library_path); FREE_C_HEAP_ARRAY(char, ld_library_path); } // Extensions directories. sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); Arguments::set_ext_dirs(buf); FREE_C_HEAP_ARRAY(char, buf); #undef DEFAULT_LIBPATH #undef SYS_EXT_DIR #undef EXTENSIONS_DIR } //////////////////////////////////////////////////////////////////////////////// // 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; 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); sigaddset(&unblocked_sigs, SIGILL); sigaddset(&unblocked_sigs, SIGSEGV); sigaddset(&unblocked_sigs, SIGBUS); sigaddset(&unblocked_sigs, SIGFPE); #if defined(PPC64) sigaddset(&unblocked_sigs, SIGTRAP); #endif sigaddset(&unblocked_sigs, SR_signum); if (!ReduceSignalUsage) { if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) { sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); } if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) { sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); } if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) { sigaddset(&unblocked_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; } 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. #if !defined(_CS_GNU_LIBC_VERSION) || \ !defined(_CS_GNU_LIBPTHREAD_VERSION) #error "glibc too old (< 2.3.2)" #endif size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0); assert(n > 0, "cannot retrieve glibc version"); char *str = (char *)malloc(n, mtInternal); confstr(_CS_GNU_LIBC_VERSION, str, n); os::Linux::set_glibc_version(str); n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0); assert(n > 0, "cannot retrieve pthread version"); str = (char *)malloc(n, mtInternal); confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n); os::Linux::set_libpthread_version(str); } ///////////////////////////////////////////////////////////////////////////// // thread stack expansion // os::Linux::manually_expand_stack() takes care of expanding the thread // stack. Note that this is normally not needed: pthread stacks allocate // thread stack using mmap() without MAP_NORESERVE, so the stack is already // committed. Therefore it is not necessary to expand the stack manually. // // Manually expanding the stack was historically needed on LinuxThreads // thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays // it is kept to deal with very rare corner cases: // // For one, user may run the VM on an own implementation of threads // whose stacks are - like the old LinuxThreads - implemented using // mmap(MAP_GROWSDOWN). // // Also, this coding may be needed if the VM is running on the primordial // thread. Normally we avoid running on the primordial thread; however, // user may still invoke the VM on the primordial thread. // // The following historical comment describes the details about running // on a thread stack allocated with mmap(MAP_GROWSDOWN): // 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 MAP_GROWSDOWN. // // 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. static void NOINLINE _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_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'; } } void os::Linux::expand_stack_to(address bottom) { _expand_stack_to(bottom); } 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_reserved_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 // Thread start routine for all newly created threads static void *thread_native_entry(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); thread->initialize_thread_current(); OSThread* osthread = thread->osthread(); Monitor* sync = osthread->startThread_lock(); osthread->set_thread_id(os::current_thread_id()); log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", os::current_thread_id(), (uintx) pthread_self()); 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(); log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", os::current_thread_id(), (uintx) pthread_self()); // If a thread has not deleted itself ("delete this") as part of its // termination sequence, we have to ensure thread-local-storage is // cleared before we actually terminate. No threads should ever be // deleted asynchronously with respect to their termination. if (Thread::current_or_null_safe() != NULL) { assert(Thread::current_or_null_safe() == thread, "current thread is wrong"); thread->clear_thread_current(); } return 0; } bool os::create_thread(Thread* thread, ThreadType thr_type, size_t req_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); // Calculate stack size if it's not specified by caller. size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size); // In the Linux NPTL pthread implementation the guard size mechanism // is not implemented properly. The posix standard requires adding // the size of the guard pages to the stack size, instead Linux // takes the space out of 'stacksize'. Thus we adapt the requested // stack_size by the size of the guard pages to mimick proper // behaviour. However, be careful not to end up with a size // of zero due to overflow. Don't add the guard page in that case. size_t guard_size = os::Linux::default_guard_size(thr_type); if (stack_size <= SIZE_MAX - guard_size) { stack_size += guard_size; } assert(is_aligned(stack_size, os::vm_page_size()), "stack_size not aligned"); int status = pthread_attr_setstacksize(&attr, stack_size); assert_status(status == 0, status, "pthread_attr_setstacksize"); // Configure glibc guard page. pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type)); ThreadState state; { pthread_t tid; int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread); char buf[64]; if (ret == 0) { log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ", (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr)); } else { log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.", os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr)); } pthread_attr_destroy(&attr); if (ret != 0) { // Need to clean up stuff we've allocated so far thread->set_osthread(NULL); delete osthread; 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); } } } // 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::is_primordial_thread()) { // If current thread is primordial 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_reserved_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); log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", os::current_thread_id(), (uintx) pthread_self()); 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"); // We are told to free resources of the argument thread, // but we can only really operate on the current thread. assert(Thread::current()->osthread() == osthread, "os::free_thread but not current thread"); #ifdef ASSERT sigset_t current; sigemptyset(¤t); pthread_sigmask(SIG_SETMASK, NULL, ¤t); assert(!sigismember(¤t, SR_signum), "SR signal should not be blocked!"); #endif // Restore caller's signal mask sigset_t sigmask = osthread->caller_sigmask(); pthread_sigmask(SIG_SETMASK, &sigmask, NULL); delete osthread; } ////////////////////////////////////////////////////////////////////////////// // primordial thread // Check if current thread is the primordial thread, similar to Solaris thr_main. bool os::is_primordial_thread(void) { if (suppress_primordial_thread_resolution) { return false; } char dummy; // If called before init complete, thread stack bottom will be null. // Can be called if fatal error occurs before initialization. if (os::Linux::initial_thread_stack_bottom() == NULL) return false; assert(os::Linux::initial_thread_stack_bottom() != NULL && os::Linux::initial_thread_stack_size() != 0, "os::init did not locate primordial thread's stack region"); if ((address)&dummy >= os::Linux::initial_thread_stack_bottom() && (address)&dummy < os::Linux::initial_thread_stack_bottom() + os::Linux::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 primordial thread stack. This special handling of primordial thread stack // is needed because pthread_getattr_np() on most (all?) Linux distros returns // bogus value for the primordial process thread. While the launcher has created // the VM in a new thread since JDK 6, we still have to allow for the use of the // JNI invocation API from a primordial thread. void os::Linux::capture_initial_stack(size_t max_size) { // max_size is either 0 (which means accept OS default for thread stacks) or // a user-specified value known to be at least the minimum needed. If we // are actually on the primordial thread we can make it appear that we have a // smaller max_size stack by inserting the guard pages at that location. But we // cannot do anything to emulate a larger stack than what has been provided by // the OS or threading library. In fact if we try to use a stack greater than // what is set by rlimit then we will crash the hosting process. // Maximum stack size is the easy part, get it from RLIMIT_STACK. // If this is "unlimited" then it will be a huge value. struct rlimit rlim; getrlimit(RLIMIT_STACK, &rlim); size_t 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. // But ensure we don't underflow the stack size - allow 1 page spare if (stack_size >= (size_t)(3 * page_size())) { stack_size -= 2 * page_size(); } // 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 (s && 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 primordial thread, good luck in the // embedded case. warning("Can't detect primordial 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 primordial 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 primordial 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_up(stack_top, page_size()); // Allowed stack value is minimum of max_size and what we derived from rlimit if (max_size > 0) { _initial_thread_stack_size = MIN2(max_size, stack_size); } else { // Accept the rlimit max, but if stack is unlimited then it will be huge, so // clamp it at 8MB as we do on Solaris _initial_thread_stack_size = MIN2(stack_size, 8*M); } _initial_thread_stack_size = align_down(_initial_thread_stack_size, page_size()); _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size; assert(_initial_thread_stack_bottom < (address)stack_top, "overflow!"); if (log_is_enabled(Info, os, thread)) { // See if we seem to be on primordial process thread bool primordial = uintptr_t(&rlim) > uintptr_t(_initial_thread_stack_bottom) && uintptr_t(&rlim) < stack_top; log_info(os, thread)("Capturing initial stack in %s thread: req. size: " SIZE_FORMAT "K, actual size: " SIZE_FORMAT "K, top=" INTPTR_FORMAT ", bottom=" INTPTR_FORMAT, primordial ? "primordial" : "user", max_size / K, _initial_thread_stack_size / K, stack_top, intptr_t(_initial_thread_stack_bottom)); } } //////////////////////////////////////////////////////////////////////////////// // 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()) / os::elapsed_frequency(); // nanosecond resolution } jlong os::elapsed_counter() { return javaTimeNanos() - initial_time_count; } jlong os::elapsed_frequency() { return NANOSECS_PER_SEC; // nanosecond resolution } bool os::supports_vtime() { return true; } bool os::enable_vtime() { return false; } bool os::vtime_enabled() { return false; } double os::elapsedVTime() { struct rusage usage; int retval = getrusage(RUSAGE_THREAD, &usage); if (retval == 0) { return (double) (usage.ru_utime.tv_sec + usage.ru_stime.tv_sec) + (double) (usage.ru_utime.tv_usec + usage.ru_stime.tv_usec) / (1000 * 1000); } else { // 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); } void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) { timeval time; int status = gettimeofday(&time, NULL); assert(status != -1, "linux error"); seconds = jlong(time.tv_sec); nanos = 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; return; } else { // close librt if there is no monotonic clock dlclose(handle); } } } warning("No monotonic clock was available - timed services may " \ "be adversely affected if the time-of-day clock changes"); } #ifndef SYS_clock_getres #if defined(X86) || defined(PPC64) || defined(S390) #define SYS_clock_getres AMD64_ONLY(229) IA32_ONLY(266) PPC64_ONLY(247) S390_ONLY(261) #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 (os::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 (os::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, void* siginfo, const void* context) { 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() { ::abort(); } // 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 = os::strerror(errno); size_t n = ::strlen(s); if (n >= len) { n = len - 1; } ::strncpy(buf, s, n); buf[n] = '\0'; return n; } // thread_id is kernel thread id (similar to Solaris LWP id) intx os::current_thread_id() { return os::Linux::gettid(); } int os::current_process_id() { return ::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; } // check if addr is inside libjvm.so bool os::address_is_in_vm(address addr) { static address libjvm_base_addr; Dl_info dlinfo; if (libjvm_base_addr == NULL) { if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { libjvm_base_addr = (address)dlinfo.dli_fbase; } assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); } if (dladdr((void *)addr, &dlinfo) != 0) { 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, bool demangle) { // buf is not optional, but offset is optional assert(buf != NULL, "sanity check"); Dl_info dlinfo; if (dladdr((void*)addr, &dlinfo) != 0) { // see if we have a matching symbol if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { if (!(demangle && 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; } // no matching symbol so try for just file info if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), buf, buflen, offset, dlinfo.dli_fname, demangle)) { return true; } } } 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) { // buf is not optional, but offset is optional assert(buf != NULL, "sanity check"); 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; } if (dladdr((void*)addr, &dlinfo) != 0) { if (dlinfo.dli_fname != NULL) { jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); } if (dlinfo.dli_fbase != NULL && offset != NULL) { *offset = addr - (address)dlinfo.dli_fbase; } return true; } 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 // Remember the stack's state. The Linux dynamic linker will change // the stack to 'executable' at most once, so we must safepoint only once. bool os::Linux::_stack_is_executable = false; // VM operation that loads a library. This is necessary if stack protection // of the Java stacks can be lost during loading the library. If we // do not stop the Java threads, they can stack overflow before the stacks // are protected again. class VM_LinuxDllLoad: public VM_Operation { private: const char *_filename; char *_ebuf; int _ebuflen; void *_lib; public: VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) : _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {} VMOp_Type type() const { return VMOp_LinuxDllLoad; } void doit() { _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen); os::Linux::_stack_is_executable = true; } void* loaded_library() { return _lib; } }; void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { void * result = NULL; bool load_attempted = false; // Check whether the library to load might change execution rights // of the stack. If they are changed, the protection of the stack // guard pages will be lost. We need a safepoint to fix this. // // See Linux man page execstack(8) for more info. if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) { if (!ElfFile::specifies_noexecstack(filename)) { if (!is_init_completed()) { os::Linux::_stack_is_executable = true; // This is OK - No Java threads have been created yet, and hence no // stack guard pages to fix. // // This should happen only when you are building JDK7 using a very // old version of JDK6 (e.g., with JPRT) and running test_gamma. // // Dynamic loader will make all stacks executable after // this function returns, and will not do that again. assert(Threads::number_of_threads() == 0, "no Java threads should exist yet."); } else { warning("You have loaded library %s which might have disabled stack guard. " "The VM will try to fix the stack guard now.\n" "It's highly recommended that you fix the library with " "'execstack -c ', or link it with '-z noexecstack'.", filename); assert(Thread::current()->is_Java_thread(), "must be Java thread"); JavaThread *jt = JavaThread::current(); if (jt->thread_state() != _thread_in_native) { // This happens when a compiler thread tries to load a hsdis-.so file // that requires ExecStack. Cannot enter safe point. Let's give up. warning("Unable to fix stack guard. Giving up."); } else { if (!LoadExecStackDllInVMThread) { // This is for the case where the DLL has an static // constructor function that executes JNI code. We cannot // load such DLLs in the VMThread. result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); } ThreadInVMfromNative tiv(jt); debug_only(VMNativeEntryWrapper vew;) VM_LinuxDllLoad op(filename, ebuf, ebuflen); VMThread::execute(&op); if (LoadExecStackDllInVMThread) { result = op.loaded_library(); } load_attempted = true; } } } } if (!load_attempted) { result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); } if (result != NULL) { // Successful loading return result; } Elf32_Ehdr elf_head; 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 unsigned char elf_class; // 32 or 64 bit unsigned char endianess; // MSB or LSB char* name; // String representation } arch_t; #ifndef EM_486 #define EM_486 6 /* Intel 80486 */ #endif #ifndef EM_AARCH64 #define EM_AARCH64 183 /* ARM AARCH64 */ #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"}, #if defined(VM_LITTLE_ENDIAN) {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64 LE"}, {EM_SH, EM_SH, ELFCLASS32, ELFDATA2LSB, (char*)"SuperH"}, #else {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}, {EM_SH, EM_SH, ELFCLASS32, ELFDATA2MSB, (char*)"SuperH BE"}, #endif {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"}, {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"}, }; #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 AARCH64) static Elf32_Half running_arch_code=EM_AARCH64; #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; #elif (defined SH) static Elf32_Half running_arch_code=EM_SH; #else #error Method os::dll_load requires that one of following is defined:\ AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, S390, SH, __sparc #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; } void * os::Linux::dlopen_helper(const char *filename, char *ebuf, int ebuflen) { void * result = ::dlopen(filename, RTLD_LAZY); if (result == NULL) { ::strncpy(ebuf, ::dlerror(), ebuflen - 1); ebuf[ebuflen-1] = '\0'; } return result; } void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf, int ebuflen) { void * result = NULL; if (LoadExecStackDllInVMThread) { result = dlopen_helper(filename, ebuf, ebuflen); } // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a // library that requires an executable stack, or which does not have this // stack attribute set, dlopen changes the stack attribute to executable. The // read protection of the guard pages gets lost. // // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad // may have been queued at the same time. if (!_stack_is_executable) { for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) { if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized jt->stack_guards_enabled()) { // No pending stack overflow exceptions if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) { warning("Attempt to reguard stack yellow zone failed."); } } } } return result; } void* os::dll_lookup(void* handle, const char* name) { void* res = dlsym(handle, name); return res; } void* os::get_default_process_handle() { return (void*)::dlopen(NULL, RTLD_LAZY); } static bool _print_ascii_file(const char* filename, outputStream* st) { int fd = ::open(filename, O_RDONLY); if (fd == -1) { return false; } char buf[33]; int bytes; buf[32] = '\0'; while ((bytes = ::read(fd, buf, sizeof(buf)-1)) > 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); } } int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) { FILE *procmapsFile = NULL; // Open the procfs maps file for the current process if ((procmapsFile = fopen("/proc/self/maps", "r")) != NULL) { // Allocate PATH_MAX for file name plus a reasonable size for other fields. char line[PATH_MAX + 100]; // Read line by line from 'file' while (fgets(line, sizeof(line), procmapsFile) != NULL) { u8 base, top, offset, inode; char permissions[5]; char device[6]; char name[PATH_MAX + 1]; // Parse fields from line sscanf(line, UINT64_FORMAT_X "-" UINT64_FORMAT_X " %4s " UINT64_FORMAT_X " %5s " INT64_FORMAT " %s", &base, &top, permissions, &offset, device, &inode, name); // Filter by device id '00:00' so that we only get file system mapped files. if (strcmp(device, "00:00") != 0) { // Call callback with the fields of interest if(callback(name, (address)base, (address)top, param)) { // Oops abort, callback aborted fclose(procmapsFile); return 1; } } } fclose(procmapsFile); } return 0; } void os::print_os_info_brief(outputStream* st) { os::Linux::print_distro_info(st); os::Posix::print_uname_info(st); os::Linux::print_libversion_info(st); } void os::print_os_info(outputStream* st) { st->print("OS:"); os::Linux::print_distro_info(st); os::Posix::print_uname_info(st); // Print warning if unsafe chroot environment detected if (unsafe_chroot_detected) { st->print("WARNING!! "); st->print_cr("%s", unstable_chroot_error); } os::Linux::print_libversion_info(st); os::Posix::print_rlimit_info(st); os::Posix::print_load_average(st); os::Linux::print_full_memory_info(st); os::Linux::print_proc_sys_info(st); os::Linux::print_container_info(st); } // Try to identify popular distros. // Most Linux distributions have a /etc/XXX-release file, which contains // the OS version string. Newer Linux distributions have a /etc/lsb-release // file that also 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. // Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have // their own specific XXX-release file as well as a redhat-release file. // Because of this the XXX-release file needs to be searched for before the // redhat-release file. // Since Red Hat and SuSE have an lsb-release file that is not very descriptive the // search for redhat-release / SuSE-release needs to be before lsb-release. // Since the lsb-release file is the new standard it needs to be searched // before the older style release files. // Searching system-release (Red Hat) and os-release (other Linuxes) are a // next to last resort. The os-release file is a new standard that contains // distribution information and the system-release file seems to be an old // standard that has been replaced by the lsb-release and os-release files. // Searching for the debian_version file is the last resort. It contains // an informative string like "6.0.6" or "wheezy/sid". Because of this // "Debian " is printed before the contents of the debian_version file. const char* distro_files[] = { "/etc/oracle-release", "/etc/mandriva-release", "/etc/mandrake-release", "/etc/sun-release", "/etc/redhat-release", "/etc/SuSE-release", "/etc/lsb-release", "/etc/turbolinux-release", "/etc/gentoo-release", "/etc/ltib-release", "/etc/angstrom-version", "/etc/system-release", "/etc/os-release", NULL }; void os::Linux::print_distro_info(outputStream* st) { for (int i = 0;; i++) { const char* file = distro_files[i]; if (file == NULL) { break; // done } // If file prints, we found it. if (_print_ascii_file(file, st)) { return; } } if (file_exists("/etc/debian_version")) { st->print("Debian "); _print_ascii_file("/etc/debian_version", st); } else { st->print("Linux"); } st->cr(); } static void parse_os_info_helper(FILE* fp, char* distro, size_t length, bool get_first_line) { char buf[256]; while (fgets(buf, sizeof(buf), fp)) { // Edit out extra stuff in expected format if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) { char* ptr = strstr(buf, "\""); // the name is in quotes if (ptr != NULL) { ptr++; // go beyond first quote char* nl = strchr(ptr, '\"'); if (nl != NULL) *nl = '\0'; strncpy(distro, ptr, length); } else { ptr = strstr(buf, "="); ptr++; // go beyond equals then char* nl = strchr(ptr, '\n'); if (nl != NULL) *nl = '\0'; strncpy(distro, ptr, length); } return; } else if (get_first_line) { char* nl = strchr(buf, '\n'); if (nl != NULL) *nl = '\0'; strncpy(distro, buf, length); return; } } // print last line and close char* nl = strchr(buf, '\n'); if (nl != NULL) *nl = '\0'; strncpy(distro, buf, length); } static void parse_os_info(char* distro, size_t length, const char* file) { FILE* fp = fopen(file, "r"); if (fp != NULL) { // if suse format, print out first line bool get_first_line = (strcmp(file, "/etc/SuSE-release") == 0); parse_os_info_helper(fp, distro, length, get_first_line); fclose(fp); } } void os::get_summary_os_info(char* buf, size_t buflen) { for (int i = 0;; i++) { const char* file = distro_files[i]; if (file == NULL) { break; // ran out of distro_files } if (file_exists(file)) { parse_os_info(buf, buflen, file); return; } } // special case for debian if (file_exists("/etc/debian_version")) { strncpy(buf, "Debian ", buflen); parse_os_info(&buf[7], buflen-7, "/etc/debian_version"); } else { strncpy(buf, "Linux", buflen); } } void os::Linux::print_libversion_info(outputStream* st) { // libc, pthread st->print("libc:"); st->print("%s ", os::Linux::glibc_version()); st->print("%s ", os::Linux::libpthread_version()); st->cr(); } void os::Linux::print_proc_sys_info(outputStream* st) { st->cr(); st->print_cr("/proc/sys/kernel/threads-max (system-wide limit on the number of threads):"); _print_ascii_file("/proc/sys/kernel/threads-max", st); st->cr(); st->cr(); st->print_cr("/proc/sys/vm/max_map_count (maximum number of memory map areas a process may have):"); _print_ascii_file("/proc/sys/vm/max_map_count", st); st->cr(); st->cr(); st->print_cr("/proc/sys/kernel/pid_max (system-wide limit on number of process identifiers):"); _print_ascii_file("/proc/sys/kernel/pid_max", st); st->cr(); st->cr(); } void os::Linux::print_full_memory_info(outputStream* st) { st->print("\n/proc/meminfo:\n"); _print_ascii_file("/proc/meminfo", st); st->cr(); } void os::Linux::print_container_info(outputStream* st) { if (!OSContainer::is_containerized()) { return; } st->print("container (cgroup) information:\n"); const char *p_ct = OSContainer::container_type(); st->print("container_type: %s\n", p_ct != NULL ? p_ct : "failed"); char *p = OSContainer::cpu_cpuset_cpus(); st->print("cpu_cpuset_cpus: %s\n", p != NULL ? p : "failed"); free(p); p = OSContainer::cpu_cpuset_memory_nodes(); st->print("cpu_memory_nodes: %s\n", p != NULL ? p : "failed"); free(p); int i = OSContainer::active_processor_count(); if (i > 0) { st->print("active_processor_count: %d\n", i); } else { st->print("active_processor_count: failed\n"); } i = OSContainer::cpu_quota(); st->print("cpu_quota: %d\n", i); i = OSContainer::cpu_period(); st->print("cpu_period: %d\n", i); i = OSContainer::cpu_shares(); st->print("cpu_shares: %d\n", i); jlong j = OSContainer::memory_limit_in_bytes(); st->print("memory_limit_in_bytes: " JLONG_FORMAT "\n", j); j = OSContainer::memory_and_swap_limit_in_bytes(); st->print("memory_and_swap_limit_in_bytes: " JLONG_FORMAT "\n", j); j = OSContainer::memory_soft_limit_in_bytes(); st->print("memory_soft_limit_in_bytes: " JLONG_FORMAT "\n", j); j = OSContainer::OSContainer::memory_usage_in_bytes(); st->print("memory_usage_in_bytes: " JLONG_FORMAT "\n", j); j = OSContainer::OSContainer::memory_max_usage_in_bytes(); st->print("memory_max_usage_in_bytes: " JLONG_FORMAT "\n", j); 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(); } // Print the first "model name" line and the first "flags" line // that we find and nothing more. We assume "model name" comes // before "flags" so if we find a second "model name", then the // "flags" field is considered missing. static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) { #if defined(IA32) || defined(AMD64) // Other platforms have less repetitive cpuinfo files FILE *fp = fopen("/proc/cpuinfo", "r"); if (fp) { while (!feof(fp)) { if (fgets(buf, buflen, fp)) { // Assume model name comes before flags bool model_name_printed = false; if (strstr(buf, "model name") != NULL) { if (!model_name_printed) { st->print_raw("CPU Model and flags from /proc/cpuinfo:\n"); st->print_raw(buf); model_name_printed = true; } else { // model name printed but not flags? Odd, just return fclose(fp); return true; } } // print the flags line too if (strstr(buf, "flags") != NULL) { st->print_raw(buf); fclose(fp); return true; } } } fclose(fp); } #endif // x86 platforms return false; } void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) { // Only print the model name if the platform provides this as a summary if (!print_model_name_and_flags(st, buf, buflen)) { st->print("\n/proc/cpuinfo:\n"); if (!_print_ascii_file("/proc/cpuinfo", st)) { st->print_cr(" "); } } } #if defined(AMD64) || defined(IA32) || defined(X32) const char* search_string = "model name"; #elif defined(M68K) const char* search_string = "CPU"; #elif defined(PPC64) const char* search_string = "cpu"; #elif defined(S390) const char* search_string = "processor"; #elif defined(SPARC) const char* search_string = "cpu"; #else const char* search_string = "Processor"; #endif // Parses the cpuinfo file for string representing the model name. void os::get_summary_cpu_info(char* cpuinfo, size_t length) { FILE* fp = fopen("/proc/cpuinfo", "r"); if (fp != NULL) { while (!feof(fp)) { char buf[256]; if (fgets(buf, sizeof(buf), fp)) { char* start = strstr(buf, search_string); if (start != NULL) { char *ptr = start + strlen(search_string); char *end = buf + strlen(buf); while (ptr != end) { // skip whitespace and colon for the rest of the name. if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') { break; } ptr++; } if (ptr != end) { // reasonable string, get rid of newline and keep the rest char* nl = strchr(buf, '\n'); if (nl != NULL) *nl = '\0'; strncpy(cpuinfo, ptr, length); fclose(fp); return; } } } } fclose(fp); } // cpuinfo not found or parsing failed, just print generic string. The entire // /proc/cpuinfo file will be printed later in the file (or enough of it for x86) #if defined(AARCH64) strncpy(cpuinfo, "AArch64", length); #elif defined(AMD64) strncpy(cpuinfo, "x86_64", length); #elif defined(ARM) // Order wrt. AARCH64 is relevant! strncpy(cpuinfo, "ARM", length); #elif defined(IA32) strncpy(cpuinfo, "x86_32", length); #elif defined(IA64) strncpy(cpuinfo, "IA64", length); #elif defined(PPC) strncpy(cpuinfo, "PPC64", length); #elif defined(S390) strncpy(cpuinfo, "S390", length); #elif defined(SPARC) strncpy(cpuinfo, "sparcv9", length); #elif defined(ZERO_LIBARCH) strncpy(cpuinfo, ZERO_LIBARCH, length); #else strncpy(cpuinfo, "unknown", length); #endif } 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, 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); #if defined(PPC64) print_signal_handler(st, SIGTRAP, buf, buflen); #endif } static char saved_jvm_path[MAXPATHLEN] = {0}; // Find the full path to the current module, libjvm.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, "cannot locate libjvm"); char *rp = NULL; if (ret && dli_fname[0] != '\0') { rp = os::Posix::realpath(dli_fname, buf, buflen); } if (rp == NULL) { return; } if (Arguments::sun_java_launcher_is_altjvm()) { // Support for the java launcher's '-XXaltjvm=' option. 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". p = strrchr(buf, '/'); if (p == NULL) { return; } assert(strstr(p, "/libjvm") == p, "invalid library name"); rp = os::Posix::realpath(java_home_var, buf, buflen); if (rp == NULL) { return; } // determine if this is a legacy image or modules image // modules image doesn't have "jre" subdirectory len = strlen(buf); assert(len < buflen, "Ran out of buffer room"); jrelib_p = buf + len; snprintf(jrelib_p, buflen-len, "/jre/lib"); if (0 != access(buf, F_OK)) { snprintf(jrelib_p, buflen-len, "/lib"); } if (0 == access(buf, F_OK)) { // Use current module name "libjvm.so" len = strlen(buf); snprintf(buf + len, buflen-len, "/hotspot/libjvm.so"); } else { // Go back to path of .so rp = os::Posix::realpath(dli_fname, buf, buflen); if (rp == NULL) { return; } } } } } strncpy(saved_jvm_path, buf, MAXPATHLEN); saved_jvm_path[MAXPATHLEN - 1] = '\0'; } 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 && VMError::is_error_reported()) { os::die(); } os::signal_notify(sig); } void* os::user_handler() { return CAST_FROM_FN_PTR(void*, UserHandler); } static struct timespec create_semaphore_timespec(unsigned int sec, int nsec) { struct timespec ts; // Semaphore's are always associated with CLOCK_REALTIME os::Linux::clock_gettime(CLOCK_REALTIME, &ts); // see os_posix.cpp for discussion on overflow checking if (sec >= MAX_SECS) { ts.tv_sec += MAX_SECS; ts.tv_nsec = 0; } else { ts.tv_sec += sec; ts.tv_nsec += nsec; if (ts.tv_nsec >= NANOSECS_PER_SEC) { ts.tv_nsec -= NANOSECS_PER_SEC; ++ts.tv_sec; // note: this must be <= max_secs } } return ts; } 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 Semaphore* sig_sem = NULL; static PosixSemaphore sr_semaphore; static void jdk_misc_signal_init() { // Initialize signal structures ::memset((void*)pending_signals, 0, sizeof(pending_signals)); // Initialize signal semaphore sig_sem = new Semaphore(); } void os::signal_notify(int sig) { if (sig_sem != NULL) { Atomic::inc(&pending_signals[sig]); sig_sem->signal(); } else { // Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init // initialization isn't called. assert(ReduceSignalUsage, "signal semaphore should be created"); } } static int check_pending_signals() { 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; } } 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() sig_sem->wait(); // 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. sig_sem->signal(); thread->java_suspend_self(); } } while (threadIsSuspended); } } int os::signal_wait() { return check_pending_signals(); } //////////////////////////////////////////////////////////////////////////////// // 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); } } static bool recoverable_mmap_error(int err) { // See if the error is one we can let the caller handle. This // list of errno values comes from JBS-6843484. I can't find a // Linux man page that documents this specific set of errno // values so while this list currently matches Solaris, it may // change as we gain experience with this failure mode. switch (err) { case EBADF: case EINVAL: case ENOTSUP: // let the caller deal with these errors return true; default: // Any remaining errors on this OS can cause our reserved mapping // to be lost. That can cause confusion where different data // structures think they have the same memory mapped. The worst // scenario is if both the VM and a library think they have the // same memory mapped. return false; } } static void warn_fail_commit_memory(char* addr, size_t size, bool exec, int err) { warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec, os::strerror(err), err); } static void warn_fail_commit_memory(char* addr, size_t size, size_t alignment_hint, bool exec, int err) { warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, alignment_hint, exec, os::strerror(err), err); } // 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. int os::Linux::commit_memory_impl(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 0; } int err = errno; // save errno from mmap() call above if (!recoverable_mmap_error(err)) { warn_fail_commit_memory(addr, size, exec, err); vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory."); } return err; } bool os::pd_commit_memory(char* addr, size_t size, bool exec) { return os::Linux::commit_memory_impl(addr, size, exec) == 0; } void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, const char* mesg) { assert(mesg != NULL, "mesg must be specified"); int err = os::Linux::commit_memory_impl(addr, size, exec); if (err != 0) { // the caller wants all commit errors to exit with the specified mesg: warn_fail_commit_memory(addr, size, exec, err); vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); } } // 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 int os::Linux::commit_memory_impl(char* addr, size_t size, size_t alignment_hint, bool exec) { int err = os::Linux::commit_memory_impl(addr, size, exec); if (err == 0) { realign_memory(addr, size, alignment_hint); } return err; } bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, bool exec) { return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0; } void os::pd_commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint, bool exec, const char* mesg) { assert(mesg != NULL, "mesg must be specified"); int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec); if (err != 0) { // the caller wants all commit errors to exit with the specified mesg: warn_fail_commit_memory(addr, size, alignment_hint, exec, err); vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); } } void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { if (UseTransparentHugePages && 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::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { // This method works by doing an mmap over an existing mmaping and effectively discarding // the existing pages. However it won't work for SHM-based large pages that cannot be // uncommitted at all. We don't do anything in this case to avoid creating a segment with // small pages on top of the SHM segment. This method always works for small pages, so we // allow that in any case. if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) { commit_memory(addr, bytes, alignment_hint, !ExecMem); } } void os::numa_make_global(char *addr, size_t bytes) { Linux::numa_interleave_memory(addr, bytes); } // Define for numa_set_bind_policy(int). Setting the argument to 0 will set the // bind policy to MPOL_PREFERRED for the current thread. #define USE_MPOL_PREFERRED 0 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { // To make NUMA and large pages more robust when both enabled, we need to ease // the requirements on where the memory should be allocated. MPOL_BIND is the // default policy and it will force memory to be allocated on the specified // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on // the specified node, but will not force it. Using this policy will prevent // getting SIGBUS when trying to allocate large pages on NUMA nodes with no // free large pages. Linux::numa_set_bind_policy(USE_MPOL_PREFERRED); Linux::numa_tonode_memory(addr, bytes, lgrp_hint); } bool os::numa_topology_changed() { return false; } size_t os::numa_get_groups_num() { // Return just the number of nodes in which it's possible to allocate memory // (in numa terminology, configured nodes). return Linux::numa_num_configured_nodes(); } 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; } int os::Linux::get_existing_num_nodes() { size_t node; size_t highest_node_number = Linux::numa_max_node(); int num_nodes = 0; // Get the total number of nodes in the system including nodes without memory. for (node = 0; node <= highest_node_number; node++) { if (isnode_in_existing_nodes(node)) { num_nodes++; } } return num_nodes; } size_t os::numa_get_leaf_groups(int *ids, size_t size) { size_t highest_node_number = Linux::numa_max_node(); size_t i = 0; // Map all node ids in which is possible to allocate memory. Also nodes are // not always consecutively available, i.e. available from 0 to the highest // node number. for (size_t node = 0; node <= highest_node_number; node++) { if (Linux::isnode_in_configured_nodes(node)) { ids[i++] = node; } } return i; } 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 = 0; 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; } void os::Linux::sched_getcpu_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) { vm_exit_during_initialization("getcpu(2) system call not supported by kernel"); } } // 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) { } // Handle request to load libnuma symbol version 1.1 (API v1). If it fails // load symbol from base version instead. 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; } // Handle request to load libnuma symbol version 1.2 (API v2) only. // Return NULL if the symbol is not defined in this particular version. void* os::Linux::libnuma_v2_dlsym(void* handle, const char* name) { return dlvsym(handle, name, "libnuma_1.2"); } bool os::Linux::libnuma_init() { if (sched_getcpu() != -1) { // Requires sched_getcpu() support 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_num_configured_nodes(CAST_TO_FN_PTR(numa_num_configured_nodes_func_t, libnuma_dlsym(handle, "numa_num_configured_nodes"))); 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"))); set_numa_interleave_memory_v2(CAST_TO_FN_PTR(numa_interleave_memory_v2_func_t, libnuma_v2_dlsym(handle, "numa_interleave_memory"))); set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t, libnuma_dlsym(handle, "numa_set_bind_policy"))); set_numa_bitmask_isbitset(CAST_TO_FN_PTR(numa_bitmask_isbitset_func_t, libnuma_dlsym(handle, "numa_bitmask_isbitset"))); set_numa_distance(CAST_TO_FN_PTR(numa_distance_func_t, libnuma_dlsym(handle, "numa_distance"))); if (numa_available() != -1) { set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes")); set_numa_all_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_all_nodes_ptr")); set_numa_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_nodes_ptr")); // Create an index -> node mapping, since nodes are not always consecutive _nindex_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray(0, true); rebuild_nindex_to_node_map(); // Create a cpu -> node mapping _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray(0, true); rebuild_cpu_to_node_map(); return true; } } } return false; } size_t os::Linux::default_guard_size(os::ThreadType thr_type) { // Creating guard page is very expensive. Java thread has HotSpot // guard pages, only enable glibc guard page for non-Java threads. // (Remember: compiler thread is a Java thread, too!) return ((thr_type == java_thread || thr_type == compiler_thread) ? 0 : page_size()); } void os::Linux::rebuild_nindex_to_node_map() { int highest_node_number = Linux::numa_max_node(); nindex_to_node()->clear(); for (int node = 0; node <= highest_node_number; node++) { if (Linux::isnode_in_existing_nodes(node)) { nindex_to_node()->append(node); } } } // 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 = 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 = get_existing_num_nodes(); int distance = 0; int closest_distance = INT_MAX; int closest_node = 0; unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal); for (size_t i = 0; i < node_num; i++) { // Check if node is configured (not a memory-less node). If it is not, find // the closest configured node. if (!isnode_in_configured_nodes(nindex_to_node()->at(i))) { closest_distance = INT_MAX; // Check distance from all remaining nodes in the system. Ignore distance // from itself and from another non-configured node. for (size_t m = 0; m < node_num; m++) { if (m != i && isnode_in_configured_nodes(nindex_to_node()->at(m))) { distance = numa_distance(nindex_to_node()->at(i), nindex_to_node()->at(m)); // If a closest node is found, update. There is always at least one // configured node in the system so there is always at least one node // close. if (distance != 0 && distance < closest_distance) { closest_distance = distance; closest_node = nindex_to_node()->at(m); } } } } else { // Current node is already a configured node. closest_node = nindex_to_node()->at(i); } // Get cpus from the original node and map them to the closest node. If node // is a configured node (not a memory-less node), then original node and // closest node are the same. if (numa_node_to_cpus(nindex_to_node()->at(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, closest_node); } } } } } } 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; GrowableArray* os::Linux::_nindex_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_num_configured_nodes_func_t os::Linux::_numa_num_configured_nodes; 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; os::Linux::numa_interleave_memory_v2_func_t os::Linux::_numa_interleave_memory_v2; os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy; os::Linux::numa_bitmask_isbitset_func_t os::Linux::_numa_bitmask_isbitset; os::Linux::numa_distance_func_t os::Linux::_numa_distance; unsigned long* os::Linux::_numa_all_nodes; struct bitmask* os::Linux::_numa_all_nodes_ptr; struct bitmask* os::Linux::_numa_nodes_ptr; bool os::pd_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; } static address get_stack_commited_bottom(address bottom, size_t size) { address nbot = bottom; address ntop = bottom + size; size_t page_sz = os::vm_page_size(); unsigned pages = size / page_sz; unsigned char vec[1]; unsigned imin = 1, imax = pages + 1, imid; int mincore_return_value = 0; assert(imin <= imax, "Unexpected page size"); while (imin < imax) { imid = (imax + imin) / 2; nbot = ntop - (imid * page_sz); // Use a trick with mincore to check whether the page is mapped or not. // mincore sets vec to 1 if page resides in memory and to 0 if page // is swapped output but if page we are asking for is unmapped // it returns -1,ENOMEM mincore_return_value = mincore(nbot, page_sz, vec); if (mincore_return_value == -1) { // Page is not mapped go up // to find first mapped page if (errno != EAGAIN) { assert(errno == ENOMEM, "Unexpected mincore errno"); imax = imid; } } else { // Page is mapped go down // to find first not mapped page imin = imid + 1; } } nbot = nbot + page_sz; // Adjust stack bottom one page up if last checked page is not mapped if (mincore_return_value == -1) { nbot = nbot + page_sz; } return nbot; } bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) { int mincore_return_value; const size_t stripe = 1024; // query this many pages each time unsigned char vec[stripe + 1]; // set a guard vec[stripe] = 'X'; const size_t page_sz = os::vm_page_size(); size_t pages = size / page_sz; assert(is_aligned(start, page_sz), "Start address must be page aligned"); assert(is_aligned(size, page_sz), "Size must be page aligned"); committed_start = NULL; int loops = (pages + stripe - 1) / stripe; int committed_pages = 0; address loop_base = start; bool found_range = false; for (int index = 0; index < loops && !found_range; index ++) { assert(pages > 0, "Nothing to do"); int pages_to_query = (pages >= stripe) ? stripe : pages; pages -= pages_to_query; // Get stable read while ((mincore_return_value = mincore(loop_base, pages_to_query * page_sz, vec)) == -1 && errno == EAGAIN); // During shutdown, some memory goes away without properly notifying NMT, // E.g. ConcurrentGCThread/WatcherThread can exit without deleting thread object. // Bailout and return as not committed for now. if (mincore_return_value == -1 && errno == ENOMEM) { return false; } assert(vec[stripe] == 'X', "overflow guard"); assert(mincore_return_value == 0, "Range must be valid"); // Process this stripe for (int vecIdx = 0; vecIdx < pages_to_query; vecIdx ++) { if ((vec[vecIdx] & 0x01) == 0) { // not committed // End of current contiguous region if (committed_start != NULL) { found_range = true; break; } } else { // committed // Start of region if (committed_start == NULL) { committed_start = loop_base + page_sz * vecIdx; } committed_pages ++; } } loop_base += pages_to_query * page_sz; } if (committed_start != NULL) { assert(committed_pages > 0, "Must have committed region"); assert(committed_pages <= int(size / page_sz), "Can not commit more than it has"); assert(committed_start >= start && committed_start < start + size, "Out of range"); committed_size = page_sz * committed_pages; return true; } else { assert(committed_pages == 0, "Should not have committed region"); return false; } } // 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. // 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. // 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/primordial thread bool os::pd_create_stack_guard_pages(char* addr, size_t size) { if (os::is_primordial_thread()) { // As we manually grow stack up to bottom inside create_attached_thread(), // it's likely that os::Linux::initial_thread_stack_bottom is mapped and // we don't need to do anything special. // Check it first, before calling heavy function. uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom(); unsigned char vec[1]; if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) { // Fallback to slow path on all errors, including EAGAIN stack_extent = (uintptr_t) get_stack_commited_bottom( os::Linux::initial_thread_stack_bottom(), (size_t)addr - stack_extent); } if (stack_extent < (uintptr_t)addr) { ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent)); } } return os::commit_memory(addr, size, !ExecMem); } // 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/primordial thread, but guard against future OS changes. // It's safe to always unmap guard pages for primordial thread because we // always place it right after end of the mapped region. bool os::remove_stack_guard_pages(char* addr, size_t size) { uintptr_t stack_extent, stack_base; if (os::is_primordial_thread()) { return ::munmap(addr, size) == 0; } return os::uncommit_memory(addr, size); } // 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 reserved/uncommitted pages PROT_NONE so we fail early if we // touch an uncommitted page. Otherwise, the read/write might // succeed if we have enough swap space to back the physical page. addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, flags, -1, 0); return addr == MAP_FAILED ? NULL : addr; } // Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address // (req_addr != NULL) or with a given alignment. // - bytes shall be a multiple of alignment. // - req_addr can be NULL. If not NULL, it must be a multiple of alignment. // - alignment sets the alignment at which memory shall be allocated. // It must be a multiple of allocation granularity. // Returns address of memory or NULL. If req_addr was not NULL, will only return // req_addr or NULL. static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) { size_t extra_size = bytes; if (req_addr == NULL && alignment > 0) { extra_size += alignment; } char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0); if (start == MAP_FAILED) { start = NULL; } else { if (req_addr != NULL) { if (start != req_addr) { ::munmap(start, extra_size); start = NULL; } } else { char* const start_aligned = align_up(start, alignment); char* const end_aligned = start_aligned + bytes; char* const end = start + extra_size; if (start_aligned > start) { ::munmap(start, start_aligned - start); } if (end_aligned < end) { ::munmap(end_aligned, end - end_aligned); } start = start_aligned; } } return start; } static int anon_munmap(char * addr, size_t size) { return ::munmap(addr, size) == 0; } char* os::pd_reserve_memory(size_t bytes, char* requested_addr, size_t alignment_hint) { return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); } bool os::pd_release_memory(char* addr, size_t size) { return anon_munmap(addr, size); } 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_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_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::transparent_huge_pages_sanity_check(bool warn, size_t page_size) { bool result = false; void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); if (p != MAP_FAILED) { void *aligned_p = align_up(p, page_size); result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0; munmap(p, page_size * 2); } if (warn && !result) { warning("TransparentHugePages is not supported by the operating system."); } return result; } 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 != MAP_FAILED) { // 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 (warn && !result) { 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 // - (bit 7) dax private memory // - (bit 8) dax shared memory // static void set_coredump_filter(bool largepages, bool dax_shared) { FILE *f; long cdm; bool filter_changed = false; if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) { return; } if (fscanf(f, "%lx", &cdm) != 1) { fclose(f); return; } rewind(f); if (largepages && (cdm & LARGEPAGES_BIT) == 0) { cdm |= LARGEPAGES_BIT; filter_changed = true; } if (dax_shared && (cdm & DAX_SHARED_BIT) == 0) { cdm |= DAX_SHARED_BIT; filter_changed = true; } if (filter_changed) { fprintf(f, "%#lx", cdm); } fclose(f); } // Large page support static size_t _large_page_size = 0; size_t os::Linux::find_large_page_size() { size_t large_page_size = 0; // 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 = AARCH64_ONLY(2 * M) AMD64_ONLY(2 * M) ARM32_ONLY(2 * M) IA32_ONLY(4 * M) IA64_ONLY(256 * M) PPC_ONLY(4 * M) S390_ONLY(1 * M) SPARC_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); } if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != large_page_size) { warning("Setting LargePageSizeInBytes has no effect on this OS. Large page size is " SIZE_FORMAT "%s.", byte_size_in_proper_unit(large_page_size), proper_unit_for_byte_size(large_page_size)); } return large_page_size; } size_t os::Linux::setup_large_page_size() { _large_page_size = Linux::find_large_page_size(); 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; } return _large_page_size; } bool os::Linux::setup_large_page_type(size_t page_size) { if (FLAG_IS_DEFAULT(UseHugeTLBFS) && FLAG_IS_DEFAULT(UseSHM) && FLAG_IS_DEFAULT(UseTransparentHugePages)) { // The type of large pages has not been specified by the user. // Try UseHugeTLBFS and then UseSHM. UseHugeTLBFS = UseSHM = true; // Don't try UseTransparentHugePages since there are known // performance issues with it turned on. This might change in the future. UseTransparentHugePages = false; } if (UseTransparentHugePages) { bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages); if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) { UseHugeTLBFS = false; UseSHM = false; return true; } UseTransparentHugePages = false; } if (UseHugeTLBFS) { bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS); if (hugetlbfs_sanity_check(warn_on_failure, page_size)) { UseSHM = false; return true; } UseHugeTLBFS = false; } return UseSHM; } void os::large_page_init() { if (!UseLargePages && !UseTransparentHugePages && !UseHugeTLBFS && !UseSHM) { // Not using large pages. return; } if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) { // The user explicitly turned off large pages. // Ignore the rest of the large pages flags. UseTransparentHugePages = false; UseHugeTLBFS = false; UseSHM = false; return; } size_t large_page_size = Linux::setup_large_page_size(); UseLargePages = Linux::setup_large_page_type(large_page_size); set_coredump_filter(true /*largepages*/, false /*dax_shared*/); } #ifndef SHM_HUGETLB #define SHM_HUGETLB 04000 #endif #define shm_warning_format(format, ...) \ do { \ if (UseLargePages && \ (!FLAG_IS_DEFAULT(UseLargePages) || \ !FLAG_IS_DEFAULT(UseSHM) || \ !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { \ warning(format, __VA_ARGS__); \ } \ } while (0) #define shm_warning(str) shm_warning_format("%s", str) #define shm_warning_with_errno(str) \ do { \ int err = errno; \ shm_warning_format(str " (error = %d)", err); \ } while (0) static char* shmat_with_alignment(int shmid, size_t bytes, size_t alignment) { assert(is_aligned(bytes, alignment), "Must be divisible by the alignment"); if (!is_aligned(alignment, SHMLBA)) { assert(false, "Code below assumes that alignment is at least SHMLBA aligned"); return NULL; } // To ensure that we get 'alignment' aligned memory from shmat, // we pre-reserve aligned virtual memory and then attach to that. char* pre_reserved_addr = anon_mmap_aligned(bytes, alignment, NULL); if (pre_reserved_addr == NULL) { // Couldn't pre-reserve aligned memory. shm_warning("Failed to pre-reserve aligned memory for shmat."); return NULL; } // SHM_REMAP is needed to allow shmat to map over an existing mapping. char* addr = (char*)shmat(shmid, pre_reserved_addr, SHM_REMAP); if ((intptr_t)addr == -1) { int err = errno; shm_warning_with_errno("Failed to attach shared memory."); assert(err != EACCES, "Unexpected error"); assert(err != EIDRM, "Unexpected error"); assert(err != EINVAL, "Unexpected error"); // Since we don't know if the kernel unmapped the pre-reserved memory area // we can't unmap it, since that would potentially unmap memory that was // mapped from other threads. return NULL; } return addr; } static char* shmat_at_address(int shmid, char* req_addr) { if (!is_aligned(req_addr, SHMLBA)) { assert(false, "Requested address needs to be SHMLBA aligned"); return NULL; } char* addr = (char*)shmat(shmid, req_addr, 0); if ((intptr_t)addr == -1) { shm_warning_with_errno("Failed to attach shared memory."); return NULL; } return addr; } static char* shmat_large_pages(int shmid, size_t bytes, size_t alignment, char* req_addr) { // If a req_addr has been provided, we assume that the caller has already aligned the address. if (req_addr != NULL) { assert(is_aligned(req_addr, os::large_page_size()), "Must be divisible by the large page size"); assert(is_aligned(req_addr, alignment), "Must be divisible by given alignment"); return shmat_at_address(shmid, req_addr); } // Since shmid has been setup with SHM_HUGETLB, shmat will automatically // return large page size aligned memory addresses when req_addr == NULL. // However, if the alignment is larger than the large page size, we have // to manually ensure that the memory returned is 'alignment' aligned. if (alignment > os::large_page_size()) { assert(is_aligned(alignment, os::large_page_size()), "Must be divisible by the large page size"); return shmat_with_alignment(shmid, bytes, alignment); } else { return shmat_at_address(shmid, NULL); } } char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment, 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"); assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address"); assert(is_aligned(req_addr, alignment), "Unaligned address"); if (!is_aligned(bytes, os::large_page_size())) { return NULL; // Fallback to small pages. } // Create a large shared memory region to attach to based on size. // Currently, size is the total size of the heap. int shmid = shmget(IPC_PRIVATE, 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". shm_warning_with_errno("Failed to reserve shared memory."); return NULL; } // Attach to the region. char* addr = shmat_large_pages(shmid, bytes, alignment, req_addr); // 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); return addr; } static void warn_on_large_pages_failure(char* req_addr, size_t bytes, int error) { assert(error == ENOMEM, "Only expect to fail if no memory is available"); bool warn_on_failure = UseLargePages && (!FLAG_IS_DEFAULT(UseLargePages) || !FLAG_IS_DEFAULT(UseHugeTLBFS) || !FLAG_IS_DEFAULT(LargePageSizeInBytes)); if (warn_on_failure) { char msg[128]; jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: " PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error); warning("%s", msg); } } char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes, char* req_addr, bool exec) { assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); assert(is_aligned(bytes, os::large_page_size()), "Unaligned size"); assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address"); int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; char* addr = (char*)::mmap(req_addr, bytes, prot, MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB, -1, 0); if (addr == MAP_FAILED) { warn_on_large_pages_failure(req_addr, bytes, errno); return NULL; } assert(is_aligned(addr, os::large_page_size()), "Must be"); return addr; } // Reserve memory using mmap(MAP_HUGETLB). // - bytes shall be a multiple of alignment. // - req_addr can be NULL. If not NULL, it must be a multiple of alignment. // - alignment sets the alignment at which memory shall be allocated. // It must be a multiple of allocation granularity. // Returns address of memory or NULL. If req_addr was not NULL, will only return // req_addr or NULL. char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes, size_t alignment, char* req_addr, bool exec) { size_t large_page_size = os::large_page_size(); assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes"); assert(is_aligned(req_addr, alignment), "Must be"); assert(is_aligned(bytes, alignment), "Must be"); // First reserve - but not commit - the address range in small pages. char* const start = anon_mmap_aligned(bytes, alignment, req_addr); if (start == NULL) { return NULL; } assert(is_aligned(start, alignment), "Must be"); char* end = start + bytes; // Find the regions of the allocated chunk that can be promoted to large pages. char* lp_start = align_up(start, large_page_size); char* lp_end = align_down(end, large_page_size); size_t lp_bytes = lp_end - lp_start; assert(is_aligned(lp_bytes, large_page_size), "Must be"); if (lp_bytes == 0) { // The mapped region doesn't even span the start and the end of a large page. // Fall back to allocate a non-special area. ::munmap(start, end - start); return NULL; } int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; void* result; // Commit small-paged leading area. if (start != lp_start) { result = ::mmap(start, lp_start - start, prot, MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, -1, 0); if (result == MAP_FAILED) { ::munmap(lp_start, end - lp_start); return NULL; } } // Commit large-paged area. result = ::mmap(lp_start, lp_bytes, prot, MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED|MAP_HUGETLB, -1, 0); if (result == MAP_FAILED) { warn_on_large_pages_failure(lp_start, lp_bytes, errno); // If the mmap above fails, the large pages region will be unmapped and we // have regions before and after with small pages. Release these regions. // // | mapped | unmapped | mapped | // ^ ^ ^ ^ // start lp_start lp_end end // ::munmap(start, lp_start - start); ::munmap(lp_end, end - lp_end); return NULL; } // Commit small-paged trailing area. if (lp_end != end) { result = ::mmap(lp_end, end - lp_end, prot, MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, -1, 0); if (result == MAP_FAILED) { ::munmap(start, lp_end - start); return NULL; } } return start; } char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes, size_t alignment, char* req_addr, bool exec) { assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); assert(is_aligned(req_addr, alignment), "Must be"); assert(is_aligned(alignment, os::vm_allocation_granularity()), "Must be"); assert(is_power_of_2(os::large_page_size()), "Must be"); assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes"); if (is_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) { return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec); } else { return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec); } } char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) { assert(UseLargePages, "only for large pages"); char* addr; if (UseSHM) { addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec); } else { assert(UseHugeTLBFS, "must be"); addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec); } if (addr != NULL) { if (UseNUMAInterleaving) { numa_make_global(addr, bytes); } // The memory is committed MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); } return addr; } bool os::Linux::release_memory_special_shm(char* base, size_t bytes) { // detaching the SHM segment will also delete it, see reserve_memory_special_shm() return shmdt(base) == 0; } bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) { return pd_release_memory(base, bytes); } bool os::release_memory_special(char* base, size_t bytes) { bool res; if (MemTracker::tracking_level() > NMT_minimal) { Tracker tkr(Tracker::release); res = os::Linux::release_memory_special_impl(base, bytes); if (res) { tkr.record((address)base, bytes); } } else { res = os::Linux::release_memory_special_impl(base, bytes); } return res; } bool os::Linux::release_memory_special_impl(char* base, size_t bytes) { assert(UseLargePages, "only for large pages"); bool res; if (UseSHM) { res = os::Linux::release_memory_special_shm(base, bytes); } else { assert(UseHugeTLBFS, "must be"); res = os::Linux::release_memory_special_huge_tlbfs(base, bytes); } return res; } size_t os::large_page_size() { return _large_page_size; } // With SysV SHM the entire memory region must be allocated as shared // memory. // HugeTLBFS allows application to commit large page memory on demand. // However, when committing memory with HugeTLBFS fails, the region // that was supposed to be committed will lose the old reservation // and allow other threads to steal that memory region. Because of this // behavior we can't commit HugeTLBFS memory. bool os::can_commit_large_page_memory() { return UseTransparentHugePages; } bool os::can_execute_large_page_memory() { return UseTransparentHugePages || UseHugeTLBFS; } char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) { assert(file_desc >= 0, "file_desc is not valid"); char* result = pd_attempt_reserve_memory_at(bytes, requested_addr); if (result != NULL) { if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) { vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory")); } } return result; } // Reserve memory at an arbitrary address, only if that area is // available (and not reserved for something else). char* os::pd_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. // 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. ptrdiff_t top_overlap = requested_addr + (bytes + gap) - base[i]; if (top_overlap >= 0 && (size_t)top_overlap < bytes) { unmap_memory(base[i], top_overlap); base[i] += top_overlap; size[i] = bytes - top_overlap; } else { ptrdiff_t bottom_overlap = base[i] + bytes - requested_addr; if (bottom_overlap >= 0 && (size_t)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) { return requested_addr; } else { return NULL; } } size_t os::read(int fd, void *buf, unsigned int nBytes) { return ::read(fd, buf, nBytes); } size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) { return ::pread(fd, buf, nBytes, offset); } // Short sleep, direct OS call. // // Note: certain versions of Linux CFS scheduler (since 2.6.23) do not guarantee // sched_yield(2) will actually give up the CPU: // // * Alone on this pariticular CPU, keeps running. // * Before the introduction of "skip_buddy" with "compat_yield" disabled // (pre 2.6.39). // // So calling this with 0 is an alternative. // void os::naked_short_sleep(jlong ms) { struct timespec req; assert(ms < 1000, "Un-interruptable sleep, short time use only"); req.tv_sec = 0; if (ms > 0) { req.tv_nsec = (ms % 1000) * 1000000; } else { req.tv_nsec = 1; } nanosleep(&req, NULL); return; } // 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::naked_yield() { sched_yield(); } //////////////////////////////////////////////////////////////////////////////// // 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[CriticalPriority + 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 -5 // 11 CriticalPriority }; 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; } } if (UseCriticalJavaThreadPriority) { os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; } 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. Currently used by JFR's OSThreadSampler // // 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, // but is checked for NULL in SR_handler as a thread termination indicator. // The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs. // // Note that resume_clear_context() and suspend_save_context() are needed // by SR_handler(), so that fetch_frame_from_ucontext() works, // which in part is used by: // - Forte Analyzer: AsyncGetCallTrace() // - StackBanging: get_frame_at_stack_banging_point() static void resume_clear_context(OSThread *osthread) { osthread->set_ucontext(NULL); osthread->set_siginfo(NULL); } 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 and JavaThreads (PC sampling) // 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_or_null_safe(); assert(thread != NULL, "Missing current thread in SR_handler"); // On some systems we have seen signal delivery get "stuck" until the signal // mask is changed as part of thread termination. Check that the current thread // has not already terminated (via SR_lock()) - else the following assertion // will fail because the thread is no longer a JavaThread as the ~JavaThread // destructor has completed. if (thread->SR_lock() == NULL) { return; } assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); OSThread* osthread = thread->osthread(); os::SuspendResume::State current = osthread->sr.state(); if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { suspend_save_context(osthread, siginfo, context); // attempt to switch the state, we assume we had a SUSPEND_REQUEST os::SuspendResume::State state = osthread->sr.suspended(); if (state == os::SuspendResume::SR_SUSPENDED) { sigset_t suspend_set; // signals for sigsuspend() sigemptyset(&suspend_set); // get current set of blocked signals and unblock resume signal pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); sigdelset(&suspend_set, SR_signum); sr_semaphore.signal(); // wait here until we are resumed while (1) { sigsuspend(&suspend_set); os::SuspendResume::State result = osthread->sr.running(); if (result == os::SuspendResume::SR_RUNNING) { sr_semaphore.signal(); break; } } } else if (state == os::SuspendResume::SR_RUNNING) { // request was cancelled, continue } else { ShouldNotReachHere(); } resume_clear_context(osthread); } else if (current == os::SuspendResume::SR_RUNNING) { // request was cancelled, continue } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { // ignore } else { // ignore } 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 > MAX2(SIGSEGV, SIGBUS) && // See 4355769. sig < NSIG) { // Must be legal signal and fit into sigflags[]. SR_signum = sig; } else { warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.", sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum); } } 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_notify(OSThread* osthread) { int status = pthread_kill(osthread->pthread_id(), SR_signum); assert_status(status == 0, status, "pthread_kill"); return status; } // "Randomly" selected value for how long we want to spin // before bailing out on suspending a thread, also how often // we send a signal to a thread we want to resume static const int RANDOMLY_LARGE_INTEGER = 1000000; static const int RANDOMLY_LARGE_INTEGER2 = 100; // 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) { assert(osthread->sr.is_running(), "thread should be running"); assert(!sr_semaphore.trywait(), "semaphore has invalid state"); // mark as suspended and send signal if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { // failed to switch, state wasn't running? ShouldNotReachHere(); return false; } if (sr_notify(osthread) != 0) { ShouldNotReachHere(); } // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED while (true) { if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) { break; } else { // timeout os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); if (cancelled == os::SuspendResume::SR_RUNNING) { return false; } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { // make sure that we consume the signal on the semaphore as well sr_semaphore.wait(); break; } else { ShouldNotReachHere(); return false; } } } guarantee(osthread->sr.is_suspended(), "Must be suspended"); return true; } static void do_resume(OSThread* osthread) { assert(osthread->sr.is_suspended(), "thread should be suspended"); assert(!sr_semaphore.trywait(), "invalid semaphore state"); if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { // failed to switch to WAKEUP_REQUEST ShouldNotReachHere(); return; } while (true) { if (sr_notify(osthread) == 0) { if (sr_semaphore.timedwait(create_semaphore_timespec(0, 2 * NANOSECS_PER_MILLISEC))) { if (osthread->sr.is_running()) { return; } } } else { ShouldNotReachHere(); } } guarantee(osthread->sr.is_running(), "Must be running!"); } /////////////////////////////////////////////////////////////////////////////////// // 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); static void signalHandler(int sig, siginfo_t* info, void* uc) { assert(info != NULL && uc != NULL, "it must be old kernel"); int orig_errno = errno; // Preserve errno value over signal handler. JVM_handle_linux_signal(sig, info, uc, true); errno = orig_errno; } // 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 sigact[NSIG]; uint64_t sigs = 0; #if (64 < NSIG-1) #error "Not all signals can be encoded in sigs. Adapt its type!" #endif 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 = NULL; sa_sigaction_t sa = NULL; 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; sigemptyset(&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, NULL); } // 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 ((((uint64_t)1 << (sig-1)) & sigs) != 0) { return &sigact[sig]; } return NULL; } void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) { assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); sigact[sig] = oldAct; sigs |= (uint64_t)1 << (sig-1); } // for diagnostic int sigflags[NSIG]; int os::Linux::get_our_sigflags(int sig) { assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); return sigflags[sig]; } void os::Linux::set_our_sigflags(int sig, int flags) { assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); if (sig > 0 && sig < NSIG) { 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("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 < NSIG, "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); #if defined(PPC64) set_signal_handler(SIGTRAP, true); #endif 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. // Log that signal checking is off only if -verbose:jni is specified. if (CheckJNICalls) { if (libjsig_is_loaded) { if (PrintJNIResolving) { tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); } check_signals = false; } if (AllowUserSignalHandlers) { if (PrintJNIResolving) { 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 * NANOSECS_PER_SEC) + tp.tv_nsec; } void os::Linux::initialize_os_info() { assert(_os_version == 0, "OS info already initialized"); struct utsname _uname; uint32_t major; uint32_t minor; uint32_t fix; int rc; // Kernel version is unknown if // verification below fails. _os_version = 0x01000000; rc = uname(&_uname); if (rc != -1) { rc = sscanf(_uname.release,"%d.%d.%d", &major, &minor, &fix); if (rc == 3) { if (major < 256 && minor < 256 && fix < 256) { // Kernel version format is as expected, // set it overriding unknown state. _os_version = (major << 16) | (minor << 8 ) | (fix << 0 ) ; } } } } uint32_t os::Linux::os_version() { assert(_os_version != 0, "not initialized"); return _os_version & 0x00FFFFFF; } bool os::Linux::os_version_is_known() { assert(_os_version != 0, "not initialized"); return _os_version & 0x01000000 ? false : true; } ///// // 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 = 0; 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]="); os::Posix::print_signal_set_short(st, &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="); os::Posix::print_sa_flags(st, 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) \ do { \ if (!sigismember(&check_signal_done, sig)) { \ os::Linux::check_signal_handler(sig); \ } \ } while (0) // 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); #if defined(PPC64) DO_SIGNAL_CHECK(SIGTRAP); #endif // ReduceSignalUsage allows the user to override these handlers // see comments at the very top and jvm_md.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); } 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; 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); // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", exception_name(sig, buf, O_BUFLEN)); } } 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:"); os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig)); tty->cr(); tty->print(" found:"); os::Posix::print_sa_flags(tty, act.sa_flags); tty->cr(); // 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, ...); // this is called _before_ most of the global arguments have been parsed void os::init(void) { char dummy; // used to get a guess on initial stack address clock_tics_per_sec = sysconf(_SC_CLK_TCK); init_random(1234567); Linux::set_page_size(sysconf(_SC_PAGESIZE)); if (Linux::page_size() == -1) { fatal("os_linux.cpp: os::init: sysconf failed (%s)", os::strerror(errno)); } init_page_sizes((size_t) Linux::page_size()); Linux::initialize_system_info(); Linux::initialize_os_info(); // _main_thread points to the thread that created/loaded the JVM. Linux::_main_thread = pthread_self(); Linux::clock_init(); initial_time_count = javaTimeNanos(); // retrieve entry point for pthread_setname_np Linux::_pthread_setname_np = (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np"); os::Posix::init(); } // To install functions for atexit system call extern "C" { static void perfMemory_exit_helper() { perfMemory_exit(); } } void os::pd_init_container_support() { OSContainer::init(); } // this is called _after_ the global arguments have been parsed jint os::init_2(void) { os::Posix::init_2(); Linux::fast_thread_clock_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(); // Initialize data for jdk.internal.misc.Signal if (!ReduceSignalUsage) { jdk_misc_signal_init(); } // Check and sets minimum stack sizes against command line options if (Posix::set_minimum_stack_sizes() == JNI_ERR) { return JNI_ERR; } suppress_primordial_thread_resolution = Arguments::created_by_java_launcher(); if (!suppress_primordial_thread_resolution) { Linux::capture_initial_stack(JavaThread::stack_size_at_create()); } #if defined(IA32) workaround_expand_exec_shield_cs_limit(); #endif Linux::libpthread_init(); Linux::sched_getcpu_init(); log_info(os)("HotSpot is running with %s, %s", Linux::glibc_version(), Linux::libpthread_version()); 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; } } if (UseParallelGC && UseNUMA && UseLargePages && !can_commit_large_page_memory()) { // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way // we can make the adaptive lgrp chunk resizing work. If the user specified both // UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn // and disable adaptive resizing. if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) { warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, " "disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)"); UseAdaptiveSizePolicy = false; UseAdaptiveNUMAChunkSizing = 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) { log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno)); } else { nbr_files.rlim_cur = nbr_files.rlim_max; status = setrlimit(RLIMIT_NOFILE, &nbr_files); if (status != 0) { log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno)); } } } // 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::init_2 atexit(perfMemory_exit_helper) failed"); } } // initialize thread priority policy prio_init(); if (!FLAG_IS_DEFAULT(AllocateHeapAt)) { set_coredump_filter(false /*largepages*/, true /*dax_shared*/); } return JNI_OK; } // 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"); } } // older glibc versions don't have this macro (which expands to // an optimized bit-counting function) so we have to roll our own #ifndef CPU_COUNT static int _cpu_count(const cpu_set_t* cpus) { int count = 0; // only look up to the number of configured processors for (int i = 0; i < os::processor_count(); i++) { if (CPU_ISSET(i, cpus)) { count++; } } return count; } #define CPU_COUNT(cpus) _cpu_count(cpus) #endif // CPU_COUNT // Get the current number of available processors for this process. // This value can change at any time during a process's lifetime. // sched_getaffinity gives an accurate answer as it accounts for cpusets. // If it appears there may be more than 1024 processors then we do a // dynamic check - see 6515172 for details. // If anything goes wrong we fallback to returning the number of online // processors - which can be greater than the number available to the process. int os::Linux::active_processor_count() { cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors cpu_set_t* cpus_p = &cpus; int cpus_size = sizeof(cpu_set_t); int configured_cpus = os::processor_count(); // upper bound on available cpus int cpu_count = 0; // old build platforms may not support dynamic cpu sets #ifdef CPU_ALLOC // To enable easy testing of the dynamic path on different platforms we // introduce a diagnostic flag: UseCpuAllocPath if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) { // kernel may use a mask bigger than cpu_set_t log_trace(os)("active_processor_count: using dynamic path %s" "- configured processors: %d", UseCpuAllocPath ? "(forced) " : "", configured_cpus); cpus_p = CPU_ALLOC(configured_cpus); if (cpus_p != NULL) { cpus_size = CPU_ALLOC_SIZE(configured_cpus); // zero it just to be safe CPU_ZERO_S(cpus_size, cpus_p); } else { // failed to allocate so fallback to online cpus int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN); log_trace(os)("active_processor_count: " "CPU_ALLOC failed (%s) - using " "online processor count: %d", os::strerror(errno), online_cpus); return online_cpus; } } else { log_trace(os)("active_processor_count: using static path - configured processors: %d", configured_cpus); } #else // CPU_ALLOC // these stubs won't be executed #define CPU_COUNT_S(size, cpus) -1 #define CPU_FREE(cpus) log_trace(os)("active_processor_count: only static path available - configured processors: %d", configured_cpus); #endif // CPU_ALLOC // pid 0 means the current thread - which we have to assume represents the process if (sched_getaffinity(0, cpus_size, cpus_p) == 0) { if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used cpu_count = CPU_COUNT_S(cpus_size, cpus_p); } else { cpu_count = CPU_COUNT(cpus_p); } log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count); } else { cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN); warning("sched_getaffinity failed (%s)- using online processor count (%d) " "which may exceed available processors", os::strerror(errno), cpu_count); } if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used CPU_FREE(cpus_p); } assert(cpu_count > 0 && cpu_count <= os::processor_count(), "sanity check"); return cpu_count; } // Determine the active processor count from one of // three different sources: // // 1. User option -XX:ActiveProcessorCount // 2. kernel os calls (sched_getaffinity or sysconf(_SC_NPROCESSORS_ONLN) // 3. extracted from cgroup cpu subsystem (shares and quotas) // // Option 1, if specified, will always override. // If the cgroup subsystem is active and configured, we // will return the min of the cgroup and option 2 results. // This is required since tools, such as numactl, that // alter cpu affinity do not update cgroup subsystem // cpuset configuration files. int os::active_processor_count() { // User has overridden the number of active processors if (ActiveProcessorCount > 0) { log_trace(os)("active_processor_count: " "active processor count set by user : %d", ActiveProcessorCount); return ActiveProcessorCount; } int active_cpus; if (OSContainer::is_containerized()) { active_cpus = OSContainer::active_processor_count(); log_trace(os)("active_processor_count: determined by OSContainer: %d", active_cpus); } else { active_cpus = os::Linux::active_processor_count(); } return active_cpus; } uint os::processor_id() { const int id = Linux::sched_getcpu(); assert(id >= 0 && id < _processor_count, "Invalid processor id"); return (uint)id; } void os::set_native_thread_name(const char *name) { if (Linux::_pthread_setname_np) { char buf [16]; // according to glibc manpage, 16 chars incl. '/0' snprintf(buf, sizeof(buf), "%s", name); buf[sizeof(buf) - 1] = '\0'; const int rc = Linux::_pthread_setname_np(pthread_self(), buf); // ERANGE should not happen; all other errors should just be ignored. assert(rc != ERANGE, "pthread_setname_np failed"); } } 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; } /// void os::SuspendedThreadTask::internal_do_task() { if (do_suspend(_thread->osthread())) { SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); do_task(context); do_resume(_thread->osthread()); } } //////////////////////////////////////////////////////////////////////////////// // debug support bool os::find(address addr, outputStream* st) { Dl_info dlinfo; memset(&dlinfo, 0, sizeof(dlinfo)); if (dladdr(addr, &dlinfo) != 0) { st->print(PTR_FORMAT ": ", p2i(addr)); if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { st->print("%s+" PTR_FORMAT, dlinfo.dli_sname, p2i(addr) - p2i(dlinfo.dli_saddr)); } else if (dlinfo.dli_fbase != NULL) { st->print("", p2i(addr) - p2i(dlinfo.dli_fbase)); } else { st->print(""); } if (dlinfo.dli_fname != NULL) { st->print(" in %s", dlinfo.dli_fname); } if (dlinfo.dli_fbase != NULL) { st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase)); } st->cr(); if (Verbose) { // decode some bytes around the PC address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 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) != 0 && 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, const methodHandle& method, JavaCallArguments* args, Thread* thread) { f(value, method, args, thread); } void os::print_statistics() { } bool 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'; } // 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 int os::open(const char *path, int oflag, int mode) { if (strlen(path) > MAX_PATH - 1) { errno = ENAMETOOLONG; return -1; } // All file descriptors that are opened in the Java process 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 // // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open(). // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor // because it saves a system call and removes a small window where the flag // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored // and we fall back to using FD_CLOEXEC (see below). #ifdef O_CLOEXEC oflag |= O_CLOEXEC; #endif int 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; } } #ifdef FD_CLOEXEC // Validate that the use of the O_CLOEXEC flag on open above worked. // With recent kernels, we will perform this check exactly once. static sig_atomic_t O_CLOEXEC_is_known_to_work = 0; if (!O_CLOEXEC_is_known_to_work) { int flags = ::fcntl(fd, F_GETFD); if (flags != -1) { if ((flags & FD_CLOEXEC) != 0) O_CLOEXEC_is_known_to_work = 1; else ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); } } #endif 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)) { 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; } // Map a block of memory. char* os::pd_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 = MAP_PRIVATE; if (read_only) { prot = PROT_READ; } else { prot = PROT_READ | PROT_WRITE; } 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::pd_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::pd_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 jlong fast_cpu_time(Thread *thread) { clockid_t clockid; int rc = os::Linux::pthread_getcpuclockid(thread->osthread()->pthread_id(), &clockid); if (rc == 0) { return os::Linux::fast_thread_cpu_time(clockid); } else { // It's possible to encounter a terminated native thread that failed // to detach itself from the VM - which should result in ESRCH. assert_status(rc == ESRCH, rc, "pthread_getcpuclockid failed"); return -1; } } // 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 fast_cpu_time(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 fast_cpu_time(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) { pid_t tid = thread->osthread()->thread_id(); char *s; char stat[2048]; int statlen; char proc_name[64]; int count; long sys_time, user_time; char cdummy; int idummy; long ldummy; FILE *fp; snprintf(proc_name, 64, "/proc/self/task/%d/stat", 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, ')'); if (s == NULL) return -1; // Skip blank chars do { s++; } while (s && 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, "%s", 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); } } extern char** environ; // 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}; pid_t pid = fork(); if (pid < 0) { // fork failed return -1; } else if (pid == 0) { // child process 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; } } } // Get the default path to the core file // Returns the length of the string int os::get_core_path(char* buffer, size_t bufferSize) { /* * Max length of /proc/sys/kernel/core_pattern is 128 characters. * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt */ const int core_pattern_len = 129; char core_pattern[core_pattern_len] = {0}; int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY); if (core_pattern_file == -1) { return -1; } ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len); ::close(core_pattern_file); if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') { return -1; } if (core_pattern[ret-1] == '\n') { core_pattern[ret-1] = '\0'; } else { core_pattern[ret] = '\0'; } char *pid_pos = strstr(core_pattern, "%p"); int written; if (core_pattern[0] == '/') { written = jio_snprintf(buffer, bufferSize, "%s", core_pattern); } else { char cwd[PATH_MAX]; const char* p = get_current_directory(cwd, PATH_MAX); if (p == NULL) { return -1; } if (core_pattern[0] == '|') { written = jio_snprintf(buffer, bufferSize, "\"%s\" (or dumping to %s/core.%d)", &core_pattern[1], p, current_process_id()); } else { written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern); } } if (written < 0) { return -1; } if (((size_t)written < bufferSize) && (pid_pos == NULL) && (core_pattern[0] != '|')) { int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY); if (core_uses_pid_file != -1) { char core_uses_pid = 0; ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1); ::close(core_uses_pid_file); if (core_uses_pid == '1') { jio_snprintf(buffer + written, bufferSize - written, ".%d", current_process_id()); } } } return strlen(buffer); } bool os::start_debugging(char *buf, int buflen) { int len = (int)strlen(buf); char *p = &buf[len]; jio_snprintf(p, buflen-len, "\n\n" "Do you want to debug the problem?\n\n" "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " UINTX_FORMAT " (" INTPTR_FORMAT ")\n" "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n" "Otherwise, press RETURN to abort...", os::current_process_id(), os::current_process_id(), os::current_thread_id(), os::current_thread_id()); bool yes = os::message_box("Unexpected Error", buf); if (yes) { // yes, user asked VM to launch debugger jio_snprintf(buf, sizeof(char)*buflen, "gdb /proc/%d/exe %d", os::current_process_id(), os::current_process_id()); os::fork_and_exec(buf); yes = false; } return yes; } // Java/Compiler thread: // // Low memory addresses // P0 +------------------------+ // | |\ Java thread created by VM does not have glibc // | glibc guard page | - guard page, attached Java thread usually has // | |/ 1 glibc guard page. // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() // | |\ // | HotSpot Guard Pages | - red, yellow and reserved pages // | |/ // +------------------------+ JavaThread::stack_reserved_zone_base() // | |\ // | Normal Stack | - // | |/ // P2 +------------------------+ Thread::stack_base() // // Non-Java thread: // // Low memory addresses // P0 +------------------------+ // | |\ // | glibc guard page | - usually 1 page // | |/ // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() // | |\ // | Normal Stack | - // | |/ // P2 +------------------------+ Thread::stack_base() // // ** P1 (aka bottom) and size (P2 = P1 - size) are the address and stack size // returned from pthread_attr_getstack(). // ** Due to NPTL implementation error, linux takes the glibc guard page out // of the stack size given in pthread_attr. We work around this for // threads created by the VM. (We adapt bottom to be P1 and size accordingly.) // #ifndef ZERO static void current_stack_region(address * bottom, size_t * size) { if (os::is_primordial_thread()) { // primordial thread needs special handling because pthread_getattr_np() // may return bogus value. *bottom = os::Linux::initial_thread_stack_bottom(); *size = os::Linux::initial_thread_stack_size(); } else { pthread_attr_t attr; int rslt = pthread_getattr_np(pthread_self(), &attr); // JVM needs to know exact stack location, abort if it fails if (rslt != 0) { if (rslt == ENOMEM) { vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np"); } else { fatal("pthread_getattr_np failed with error = %d", rslt); } } if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { fatal("Cannot locate current stack attributes!"); } // Work around NPTL stack guard error. size_t guard_size = 0; rslt = pthread_attr_getguardsize(&attr, &guard_size); if (rslt != 0) { fatal("pthread_attr_getguardsize failed with error = %d", rslt); } *bottom += guard_size; *size -= guard_size; pthread_attr_destroy(&attr); } assert(os::current_stack_pointer() >= *bottom && os::current_stack_pointer() < *bottom + *size, "just checking"); } address os::current_stack_base() { address bottom; size_t size; current_stack_region(&bottom, &size); return (bottom + size); } size_t os::current_stack_size() { // This stack size includes the usable stack and HotSpot guard pages // (for the threads that have Hotspot guard pages). address bottom; size_t size; current_stack_region(&bottom, &size); return size; } #endif static inline struct timespec get_mtime(const char* filename) { struct stat st; int ret = os::stat(filename, &st); assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno)); return st.st_mtim; } int os::compare_file_modified_times(const char* file1, const char* file2) { struct timespec filetime1 = get_mtime(file1); struct timespec filetime2 = get_mtime(file2); int diff = filetime1.tv_sec - filetime2.tv_sec; if (diff == 0) { return filetime1.tv_nsec - filetime2.tv_nsec; } return diff; } /////////////// Unit tests /////////////// #ifndef PRODUCT #define test_log(...) \ do { \ if (VerboseInternalVMTests) { \ tty->print_cr(__VA_ARGS__); \ tty->flush(); \ } \ } while (false) class TestReserveMemorySpecial : AllStatic { public: static void small_page_write(void* addr, size_t size) { size_t page_size = os::vm_page_size(); char* end = (char*)addr + size; for (char* p = (char*)addr; p < end; p += page_size) { *p = 1; } } static void test_reserve_memory_special_huge_tlbfs_only(size_t size) { if (!UseHugeTLBFS) { return; } test_log("test_reserve_memory_special_huge_tlbfs_only(" SIZE_FORMAT ")", size); char* addr = os::Linux::reserve_memory_special_huge_tlbfs_only(size, NULL, false); if (addr != NULL) { small_page_write(addr, size); os::Linux::release_memory_special_huge_tlbfs(addr, size); } } static void test_reserve_memory_special_huge_tlbfs_only() { if (!UseHugeTLBFS) { return; } size_t lp = os::large_page_size(); for (size_t size = lp; size <= lp * 10; size += lp) { test_reserve_memory_special_huge_tlbfs_only(size); } } static void test_reserve_memory_special_huge_tlbfs_mixed() { size_t lp = os::large_page_size(); size_t ag = os::vm_allocation_granularity(); // sizes to test const size_t sizes[] = { lp, lp + ag, lp + lp / 2, lp * 2, lp * 2 + ag, lp * 2 - ag, lp * 2 + lp / 2, lp * 10, lp * 10 + lp / 2 }; const int num_sizes = sizeof(sizes) / sizeof(size_t); // For each size/alignment combination, we test three scenarios: // 1) with req_addr == NULL // 2) with a non-null req_addr at which we expect to successfully allocate // 3) with a non-null req_addr which contains a pre-existing mapping, at which we // expect the allocation to either fail or to ignore req_addr // Pre-allocate two areas; they shall be as large as the largest allocation // and aligned to the largest alignment we will be testing. const size_t mapping_size = sizes[num_sizes - 1] * 2; char* const mapping1 = (char*) ::mmap(NULL, mapping_size, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0); assert(mapping1 != MAP_FAILED, "should work"); char* const mapping2 = (char*) ::mmap(NULL, mapping_size, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0); assert(mapping2 != MAP_FAILED, "should work"); // Unmap the first mapping, but leave the second mapping intact: the first // mapping will serve as a value for a "good" req_addr (case 2). The second // mapping, still intact, as "bad" req_addr (case 3). ::munmap(mapping1, mapping_size); // Case 1 test_log("%s, req_addr NULL:", __FUNCTION__); test_log("size align result"); for (int i = 0; i < num_sizes; i++) { const size_t size = sizes[i]; for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, NULL, false); test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " -> " PTR_FORMAT " %s", size, alignment, p2i(p), (p != NULL ? "" : "(failed)")); if (p != NULL) { assert(is_aligned(p, alignment), "must be"); small_page_write(p, size); os::Linux::release_memory_special_huge_tlbfs(p, size); } } } // Case 2 test_log("%s, req_addr non-NULL:", __FUNCTION__); test_log("size align req_addr result"); for (int i = 0; i < num_sizes; i++) { const size_t size = sizes[i]; for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { char* const req_addr = align_up(mapping1, alignment); char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false); test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s", size, alignment, p2i(req_addr), p2i(p), ((p != NULL ? (p == req_addr ? "(exact match)" : "") : "(failed)"))); if (p != NULL) { assert(p == req_addr, "must be"); small_page_write(p, size); os::Linux::release_memory_special_huge_tlbfs(p, size); } } } // Case 3 test_log("%s, req_addr non-NULL with preexisting mapping:", __FUNCTION__); test_log("size align req_addr result"); for (int i = 0; i < num_sizes; i++) { const size_t size = sizes[i]; for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { char* const req_addr = align_up(mapping2, alignment); char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false); test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s", size, alignment, p2i(req_addr), p2i(p), ((p != NULL ? "" : "(failed)"))); // as the area around req_addr contains already existing mappings, the API should always // return NULL (as per contract, it cannot return another address) assert(p == NULL, "must be"); } } ::munmap(mapping2, mapping_size); } static void test_reserve_memory_special_huge_tlbfs() { if (!UseHugeTLBFS) { return; } test_reserve_memory_special_huge_tlbfs_only(); test_reserve_memory_special_huge_tlbfs_mixed(); } static void test_reserve_memory_special_shm(size_t size, size_t alignment) { if (!UseSHM) { return; } test_log("test_reserve_memory_special_shm(" SIZE_FORMAT ", " SIZE_FORMAT ")", size, alignment); char* addr = os::Linux::reserve_memory_special_shm(size, alignment, NULL, false); if (addr != NULL) { assert(is_aligned(addr, alignment), "Check"); assert(is_aligned(addr, os::large_page_size()), "Check"); small_page_write(addr, size); os::Linux::release_memory_special_shm(addr, size); } } static void test_reserve_memory_special_shm() { size_t lp = os::large_page_size(); size_t ag = os::vm_allocation_granularity(); for (size_t size = ag; size < lp * 3; size += ag) { for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { test_reserve_memory_special_shm(size, alignment); } } } static void test() { test_reserve_memory_special_huge_tlbfs(); test_reserve_memory_special_shm(); } }; void TestReserveMemorySpecial_test() { TestReserveMemorySpecial::test(); } #endif