/* * Copyright (c) 1997, 2016, 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. * */ #include "precompiled.hpp" #include "classfile/classLoader.hpp" #include "classfile/javaClasses.hpp" #include "classfile/systemDictionary.hpp" #include "classfile/vmSymbols.hpp" #include "code/icBuffer.hpp" #include "code/vtableStubs.hpp" #include "gc_implementation/shared/vmGCOperations.hpp" #include "interpreter/interpreter.hpp" #include "memory/allocation.inline.hpp" #ifdef ASSERT #include "memory/guardedMemory.hpp" #endif #include "oops/oop.inline.hpp" #include "prims/jvm.h" #include "prims/jvm_misc.hpp" #include "prims/privilegedStack.hpp" #include "runtime/arguments.hpp" #include "runtime/frame.inline.hpp" #include "runtime/interfaceSupport.hpp" #include "runtime/java.hpp" #include "runtime/javaCalls.hpp" #include "runtime/mutexLocker.hpp" #include "runtime/os.hpp" #include "runtime/stubRoutines.hpp" #include "runtime/thread.inline.hpp" #include "services/attachListener.hpp" #include "services/nmtCommon.hpp" #include "services/mallocTracker.hpp" #include "services/memTracker.hpp" #include "services/threadService.hpp" #include "utilities/defaultStream.hpp" #include "utilities/events.hpp" #ifdef TARGET_OS_FAMILY_linux # include "os_linux.inline.hpp" #endif #ifdef TARGET_OS_FAMILY_solaris # include "os_solaris.inline.hpp" #endif #ifdef TARGET_OS_FAMILY_windows # include "os_windows.inline.hpp" #endif #ifdef TARGET_OS_FAMILY_bsd # include "os_bsd.inline.hpp" #endif # include PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC OSThread* os::_starting_thread = NULL; address os::_polling_page = NULL; volatile int32_t* os::_mem_serialize_page = NULL; uintptr_t os::_serialize_page_mask = 0; long os::_rand_seed = 1; int os::_processor_count = 0; int os::_initial_active_processor_count = 0; size_t os::_page_sizes[os::page_sizes_max]; #ifndef PRODUCT julong os::num_mallocs = 0; // # of calls to malloc/realloc julong os::alloc_bytes = 0; // # of bytes allocated julong os::num_frees = 0; // # of calls to free julong os::free_bytes = 0; // # of bytes freed #endif static juint cur_malloc_words = 0; // current size for MallocMaxTestWords void os_init_globals() { // Called from init_globals(). // See Threads::create_vm() in thread.cpp, and init.cpp. os::init_globals(); } // Fill in buffer with current local time as an ISO-8601 string. // E.g., yyyy-mm-ddThh:mm:ss-zzzz. // Returns buffer, or NULL if it failed. // This would mostly be a call to // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....) // except that on Windows the %z behaves badly, so we do it ourselves. // Also, people wanted milliseconds on there, // and strftime doesn't do milliseconds. char* os::iso8601_time(char* buffer, size_t buffer_length) { // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0" // 1 2 // 12345678901234567890123456789 static const char* iso8601_format = "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d"; static const size_t needed_buffer = 29; // Sanity check the arguments if (buffer == NULL) { assert(false, "NULL buffer"); return NULL; } if (buffer_length < needed_buffer) { assert(false, "buffer_length too small"); return NULL; } // Get the current time jlong milliseconds_since_19700101 = javaTimeMillis(); const int milliseconds_per_microsecond = 1000; const time_t seconds_since_19700101 = milliseconds_since_19700101 / milliseconds_per_microsecond; const int milliseconds_after_second = milliseconds_since_19700101 % milliseconds_per_microsecond; // Convert the time value to a tm and timezone variable struct tm time_struct; if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) { assert(false, "Failed localtime_pd"); return NULL; } #if defined(_ALLBSD_SOURCE) const time_t zone = (time_t) time_struct.tm_gmtoff; #else const time_t zone = timezone; #endif // If daylight savings time is in effect, // we are 1 hour East of our time zone const time_t seconds_per_minute = 60; const time_t minutes_per_hour = 60; const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour; time_t UTC_to_local = zone; if (time_struct.tm_isdst > 0) { UTC_to_local = UTC_to_local - seconds_per_hour; } // Compute the time zone offset. // localtime_pd() sets timezone to the difference (in seconds) // between UTC and and local time. // ISO 8601 says we need the difference between local time and UTC, // we change the sign of the localtime_pd() result. const time_t local_to_UTC = -(UTC_to_local); // Then we have to figure out if if we are ahead (+) or behind (-) UTC. char sign_local_to_UTC = '+'; time_t abs_local_to_UTC = local_to_UTC; if (local_to_UTC < 0) { sign_local_to_UTC = '-'; abs_local_to_UTC = -(abs_local_to_UTC); } // Convert time zone offset seconds to hours and minutes. const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour); const time_t zone_min = ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute); // Print an ISO 8601 date and time stamp into the buffer const int year = 1900 + time_struct.tm_year; const int month = 1 + time_struct.tm_mon; const int printed = jio_snprintf(buffer, buffer_length, iso8601_format, year, month, time_struct.tm_mday, time_struct.tm_hour, time_struct.tm_min, time_struct.tm_sec, milliseconds_after_second, sign_local_to_UTC, zone_hours, zone_min); if (printed == 0) { assert(false, "Failed jio_printf"); return NULL; } return buffer; } OSReturn os::set_priority(Thread* thread, ThreadPriority p) { #ifdef ASSERT if (!(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self() || thread->is_Compiler_thread() )) { assert(false, "possibility of dangling Thread pointer"); } #endif if (p >= MinPriority && p <= MaxPriority) { int priority = java_to_os_priority[p]; return set_native_priority(thread, priority); } else { assert(false, "Should not happen"); return OS_ERR; } } // The mapping from OS priority back to Java priority may be inexact because // Java priorities can map M:1 with native priorities. If you want the definite // Java priority then use JavaThread::java_priority() OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) { int p; int os_prio; OSReturn ret = get_native_priority(thread, &os_prio); if (ret != OS_OK) return ret; if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) { for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ; } else { // niceness values are in reverse order for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ; } priority = (ThreadPriority)p; return OS_OK; } // --------------------- sun.misc.Signal (optional) --------------------- // SIGBREAK is sent by the keyboard to query the VM state #ifndef SIGBREAK #define SIGBREAK SIGQUIT #endif // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread. static void signal_thread_entry(JavaThread* thread, TRAPS) { os::set_priority(thread, NearMaxPriority); while (true) { int sig; { // FIXME : Currently we have not decieded what should be the status // for this java thread blocked here. Once we decide about // that we should fix this. sig = os::signal_wait(); } if (sig == os::sigexitnum_pd()) { // Terminate the signal thread return; } switch (sig) { case SIGBREAK: { // Check if the signal is a trigger to start the Attach Listener - in that // case don't print stack traces. if (!DisableAttachMechanism && AttachListener::is_init_trigger()) { continue; } // Print stack traces // Any SIGBREAK operations added here should make sure to flush // the output stream (e.g. tty->flush()) after output. See 4803766. // Each module also prints an extra carriage return after its output. VM_PrintThreads op; VMThread::execute(&op); VM_PrintJNI jni_op; VMThread::execute(&jni_op); VM_FindDeadlocks op1(tty); VMThread::execute(&op1); Universe::print_heap_at_SIGBREAK(); if (PrintClassHistogram) { VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */); VMThread::execute(&op1); } if (JvmtiExport::should_post_data_dump()) { JvmtiExport::post_data_dump(); } break; } default: { // Dispatch the signal to java HandleMark hm(THREAD); Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD); KlassHandle klass (THREAD, k); if (klass.not_null()) { JavaValue result(T_VOID); JavaCallArguments args; args.push_int(sig); JavaCalls::call_static( &result, klass, vmSymbols::dispatch_name(), vmSymbols::int_void_signature(), &args, THREAD ); } if (HAS_PENDING_EXCEPTION) { // tty is initialized early so we don't expect it to be null, but // if it is we can't risk doing an initialization that might // trigger additional out-of-memory conditions if (tty != NULL) { char klass_name[256]; char tmp_sig_name[16]; const char* sig_name = "UNKNOWN"; InstanceKlass::cast(PENDING_EXCEPTION->klass())-> name()->as_klass_external_name(klass_name, 256); if (os::exception_name(sig, tmp_sig_name, 16) != NULL) sig_name = tmp_sig_name; warning("Exception %s occurred dispatching signal %s to handler" "- the VM may need to be forcibly terminated", klass_name, sig_name ); } CLEAR_PENDING_EXCEPTION; } } } } } void os::init_before_ergo() { initialize_initial_active_processor_count(); // We need to initialize large page support here because ergonomics takes some // decisions depending on large page support and the calculated large page size. large_page_init(); // VM version initialization identifies some characteristics of the // the platform that are used during ergonomic decisions. VM_Version::init_before_ergo(); } void os::signal_init() { if (!ReduceSignalUsage) { // Setup JavaThread for processing signals EXCEPTION_MARK; Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK); instanceKlassHandle klass (THREAD, k); instanceHandle thread_oop = klass->allocate_instance_handle(CHECK); const char thread_name[] = "Signal Dispatcher"; Handle string = java_lang_String::create_from_str(thread_name, CHECK); // Initialize thread_oop to put it into the system threadGroup Handle thread_group (THREAD, Universe::system_thread_group()); JavaValue result(T_VOID); JavaCalls::call_special(&result, thread_oop, klass, vmSymbols::object_initializer_name(), vmSymbols::threadgroup_string_void_signature(), thread_group, string, CHECK); KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass()); JavaCalls::call_special(&result, thread_group, group, vmSymbols::add_method_name(), vmSymbols::thread_void_signature(), thread_oop, // ARG 1 CHECK); os::signal_init_pd(); { MutexLocker mu(Threads_lock); JavaThread* signal_thread = new JavaThread(&signal_thread_entry); // At this point it may be possible that no osthread was created for the // JavaThread due to lack of memory. We would have to throw an exception // in that case. However, since this must work and we do not allow // exceptions anyway, check and abort if this fails. if (signal_thread == NULL || signal_thread->osthread() == NULL) { vm_exit_during_initialization("java.lang.OutOfMemoryError", "unable to create new native thread"); } java_lang_Thread::set_thread(thread_oop(), signal_thread); java_lang_Thread::set_priority(thread_oop(), NearMaxPriority); java_lang_Thread::set_daemon(thread_oop()); signal_thread->set_threadObj(thread_oop()); Threads::add(signal_thread); Thread::start(signal_thread); } // Handle ^BREAK os::signal(SIGBREAK, os::user_handler()); } } void os::terminate_signal_thread() { if (!ReduceSignalUsage) signal_notify(sigexitnum_pd()); } // --------------------- loading libraries --------------------- typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *); extern struct JavaVM_ main_vm; static void* _native_java_library = NULL; void* os::native_java_library() { if (_native_java_library == NULL) { char buffer[JVM_MAXPATHLEN]; char ebuf[1024]; // Try to load verify dll first. In 1.3 java dll depends on it and is not // always able to find it when the loading executable is outside the JDK. // In order to keep working with 1.2 we ignore any loading errors. if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "verify")) { dll_load(buffer, ebuf, sizeof(ebuf)); } // Load java dll if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "java")) { _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf)); } if (_native_java_library == NULL) { vm_exit_during_initialization("Unable to load native library", ebuf); } #if defined(__OpenBSD__) // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so // ignore errors if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "net")) { dll_load(buffer, ebuf, sizeof(ebuf)); } #endif } static jboolean onLoaded = JNI_FALSE; if (onLoaded) { // We may have to wait to fire OnLoad until TLS is initialized. if (ThreadLocalStorage::is_initialized()) { // The JNI_OnLoad handling is normally done by method load in // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library // explicitly so we have to check for JNI_OnLoad as well const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS; JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR( JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0])); if (JNI_OnLoad != NULL) { JavaThread* thread = JavaThread::current(); ThreadToNativeFromVM ttn(thread); HandleMark hm(thread); jint ver = (*JNI_OnLoad)(&main_vm, NULL); onLoaded = JNI_TRUE; if (!Threads::is_supported_jni_version_including_1_1(ver)) { vm_exit_during_initialization("Unsupported JNI version"); } } } } return _native_java_library; } /* * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists. * If check_lib == true then we are looking for an * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if * this library is statically linked into the image. * If check_lib == false then we will look for the appropriate symbol in the * executable if agent_lib->is_static_lib() == true or in the shared library * referenced by 'handle'. */ void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib, const char *syms[], size_t syms_len) { assert(agent_lib != NULL, "sanity check"); const char *lib_name; void *handle = agent_lib->os_lib(); void *entryName = NULL; char *agent_function_name; size_t i; // If checking then use the agent name otherwise test is_static_lib() to // see how to process this lookup lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL); for (i = 0; i < syms_len; i++) { agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path()); if (agent_function_name == NULL) { break; } entryName = dll_lookup(handle, agent_function_name); FREE_C_HEAP_ARRAY(char, agent_function_name, mtThread); if (entryName != NULL) { break; } } return entryName; } // See if the passed in agent is statically linked into the VM image. bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[], size_t syms_len) { void *ret; void *proc_handle; void *save_handle; assert(agent_lib != NULL, "sanity check"); if (agent_lib->name() == NULL) { return false; } proc_handle = get_default_process_handle(); // Check for Agent_OnLoad/Attach_lib_name function save_handle = agent_lib->os_lib(); // We want to look in this process' symbol table. agent_lib->set_os_lib(proc_handle); ret = find_agent_function(agent_lib, true, syms, syms_len); if (ret != NULL) { // Found an entry point like Agent_OnLoad_lib_name so we have a static agent agent_lib->set_valid(); agent_lib->set_static_lib(true); return true; } agent_lib->set_os_lib(save_handle); return false; } // --------------------- heap allocation utilities --------------------- char *os::strdup(const char *str, MEMFLAGS flags) { size_t size = strlen(str); char *dup_str = (char *)malloc(size + 1, flags); if (dup_str == NULL) return NULL; strcpy(dup_str, str); return dup_str; } #define paranoid 0 /* only set to 1 if you suspect checking code has bug */ #ifdef ASSERT static void verify_memory(void* ptr) { GuardedMemory guarded(ptr); if (!guarded.verify_guards()) { tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees); tty->print_cr("## memory stomp:"); guarded.print_on(tty); fatal("memory stomping error"); } } #endif // // This function supports testing of the malloc out of memory // condition without really running the system out of memory. // static u_char* testMalloc(size_t alloc_size) { assert(MallocMaxTestWords > 0, "sanity check"); if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) { return NULL; } u_char* ptr = (u_char*)::malloc(alloc_size); if (ptr != NULL) { Atomic::add(((jint) (alloc_size / BytesPerWord)), (volatile jint *) &cur_malloc_words); } return ptr; } void* os::malloc(size_t size, MEMFLAGS flags) { return os::malloc(size, flags, CALLER_PC); } void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) { NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); #ifdef ASSERT // checking for the WatcherThread and crash_protection first // since os::malloc can be called when the libjvm.{dll,so} is // first loaded and we don't have a thread yet. // try to find the thread after we see that the watcher thread // exists and has crash protection. WatcherThread *wt = WatcherThread::watcher_thread(); if (wt != NULL && wt->has_crash_protection()) { Thread* thread = ThreadLocalStorage::get_thread_slow(); if (thread == wt) { assert(!wt->has_crash_protection(), "Can't malloc with crash protection from WatcherThread"); } } #endif if (size == 0) { // return a valid pointer if size is zero // if NULL is returned the calling functions assume out of memory. size = 1; } // NMT support NMT_TrackingLevel level = MemTracker::tracking_level(); size_t nmt_header_size = MemTracker::malloc_header_size(level); #ifndef ASSERT const size_t alloc_size = size + nmt_header_size; #else const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size); if (size + nmt_header_size > alloc_size) { // Check for rollover. return NULL; } #endif NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap()); u_char* ptr; if (MallocMaxTestWords > 0) { ptr = testMalloc(alloc_size); } else { ptr = (u_char*)::malloc(alloc_size); } #ifdef ASSERT if (ptr == NULL) { return NULL; } // Wrap memory with guard GuardedMemory guarded(ptr, size + nmt_header_size); ptr = guarded.get_user_ptr(); #endif if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) { tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr); breakpoint(); } debug_only(if (paranoid) verify_memory(ptr)); if (PrintMalloc && tty != NULL) { tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr); } // we do not track guard memory return MemTracker::record_malloc((address)ptr, size, memflags, stack, level); } void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) { return os::realloc(memblock, size, flags, CALLER_PC); } void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) { #ifndef ASSERT NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1)); NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size)); // NMT support void* membase = MemTracker::record_free(memblock); NMT_TrackingLevel level = MemTracker::tracking_level(); size_t nmt_header_size = MemTracker::malloc_header_size(level); void* ptr = ::realloc(membase, size + nmt_header_size); return MemTracker::record_malloc(ptr, size, memflags, stack, level); #else if (memblock == NULL) { return os::malloc(size, memflags, stack); } if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { tty->print_cr("os::realloc caught " PTR_FORMAT, memblock); breakpoint(); } // NMT support void* membase = MemTracker::malloc_base(memblock); verify_memory(membase); NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap()); if (size == 0) { return NULL; } // always move the block void* ptr = os::malloc(size, memflags, stack); if (PrintMalloc) { tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr); } // Copy to new memory if malloc didn't fail if ( ptr != NULL ) { GuardedMemory guarded(MemTracker::malloc_base(memblock)); // Guard's user data contains NMT header size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock); memcpy(ptr, memblock, MIN2(size, memblock_size)); if (paranoid) verify_memory(MemTracker::malloc_base(ptr)); if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) { tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr); breakpoint(); } os::free(memblock); } return ptr; #endif } void os::free(void *memblock, MEMFLAGS memflags) { NOT_PRODUCT(inc_stat_counter(&num_frees, 1)); #ifdef ASSERT if (memblock == NULL) return; if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock); breakpoint(); } void* membase = MemTracker::record_free(memblock); verify_memory(membase); NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap()); GuardedMemory guarded(membase); size_t size = guarded.get_user_size(); inc_stat_counter(&free_bytes, size); membase = guarded.release_for_freeing(); if (PrintMalloc && tty != NULL) { fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)membase); } ::free(membase); #else void* membase = MemTracker::record_free(memblock); ::free(membase); #endif } void os::init_random(long initval) { _rand_seed = initval; } long os::random() { /* standard, well-known linear congruential random generator with * next_rand = (16807*seed) mod (2**31-1) * see * (1) "Random Number Generators: Good Ones Are Hard to Find", * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988), * (2) "Two Fast Implementations of the 'Minimal Standard' Random * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88. */ const long a = 16807; const unsigned long m = 2147483647; const long q = m / a; assert(q == 127773, "weird math"); const long r = m % a; assert(r == 2836, "weird math"); // compute az=2^31p+q unsigned long lo = a * (long)(_rand_seed & 0xFFFF); unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16); lo += (hi & 0x7FFF) << 16; // if q overflowed, ignore the overflow and increment q if (lo > m) { lo &= m; ++lo; } lo += hi >> 15; // if (p+q) overflowed, ignore the overflow and increment (p+q) if (lo > m) { lo &= m; ++lo; } return (_rand_seed = lo); } // The INITIALIZED state is distinguished from the SUSPENDED state because the // conditions in which a thread is first started are different from those in which // a suspension is resumed. These differences make it hard for us to apply the // tougher checks when starting threads that we want to do when resuming them. // However, when start_thread is called as a result of Thread.start, on a Java // thread, the operation is synchronized on the Java Thread object. So there // cannot be a race to start the thread and hence for the thread to exit while // we are working on it. Non-Java threads that start Java threads either have // to do so in a context in which races are impossible, or should do appropriate // locking. void os::start_thread(Thread* thread) { // guard suspend/resume MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag); OSThread* osthread = thread->osthread(); osthread->set_state(RUNNABLE); pd_start_thread(thread); } //--------------------------------------------------------------------------- // Helper functions for fatal error handler void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) { assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking"); int cols = 0; int cols_per_line = 0; switch (unitsize) { case 1: cols_per_line = 16; break; case 2: cols_per_line = 8; break; case 4: cols_per_line = 4; break; case 8: cols_per_line = 2; break; default: return; } address p = start; st->print(PTR_FORMAT ": ", start); while (p < end) { switch (unitsize) { case 1: st->print("%02x", *(u1*)p); break; case 2: st->print("%04x", *(u2*)p); break; case 4: st->print("%08x", *(u4*)p); break; case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break; } p += unitsize; cols++; if (cols >= cols_per_line && p < end) { cols = 0; st->cr(); st->print(PTR_FORMAT ": ", p); } else { st->print(" "); } } st->cr(); } void os::print_environment_variables(outputStream* st, const char** env_list, char* buffer, int len) { if (env_list) { st->print_cr("Environment Variables:"); for (int i = 0; env_list[i] != NULL; i++) { if (getenv(env_list[i], buffer, len)) { st->print("%s", env_list[i]); st->print("="); st->print_cr("%s", buffer); } } } } void os::print_cpu_info(outputStream* st) { // cpu st->print("CPU:"); st->print("total %d", os::processor_count()); // It's not safe to query number of active processors after crash // st->print("(active %d)", os::active_processor_count()); but we can // print the initial number of active processors. // We access the raw value here because the assert in the accessor will // fail if the crash occurs before initialization of this value. st->print(" (initial active %d)", _initial_active_processor_count); st->print(" %s", VM_Version::cpu_features()); st->cr(); pd_print_cpu_info(st); } void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) { const int secs_per_day = 86400; const int secs_per_hour = 3600; const int secs_per_min = 60; time_t tloc; (void)time(&tloc); st->print("time: %s", ctime(&tloc)); // ctime adds newline. struct tm tz; if (localtime_pd(&tloc, &tz) != NULL) { ::strftime(buf, buflen, "%Z", &tz); st->print_cr("timezone: %s", buf); } double t = os::elapsedTime(); // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in // Linux. Must be a bug in glibc ? Workaround is to round "t" to int // before printf. We lost some precision, but who cares? int eltime = (int)t; // elapsed time in seconds // print elapsed time in a human-readable format: int eldays = eltime / secs_per_day; int day_secs = eldays * secs_per_day; int elhours = (eltime - day_secs) / secs_per_hour; int hour_secs = elhours * secs_per_hour; int elmins = (eltime - day_secs - hour_secs) / secs_per_min; int minute_secs = elmins * secs_per_min; int elsecs = (eltime - day_secs - hour_secs - minute_secs); st->print_cr("elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs); } // moved from debug.cpp (used to be find()) but still called from there // The verbose parameter is only set by the debug code in one case void os::print_location(outputStream* st, intptr_t x, bool verbose) { address addr = (address)x; CodeBlob* b = CodeCache::find_blob_unsafe(addr); if (b != NULL) { if (b->is_buffer_blob()) { // the interpreter is generated into a buffer blob InterpreterCodelet* i = Interpreter::codelet_containing(addr); if (i != NULL) { st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin())); i->print_on(st); return; } if (Interpreter::contains(addr)) { st->print_cr(INTPTR_FORMAT " is pointing into interpreter code" " (not bytecode specific)", addr); return; } // if (AdapterHandlerLibrary::contains(b)) { st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin())); AdapterHandlerLibrary::print_handler_on(st, b); } // the stubroutines are generated into a buffer blob StubCodeDesc* d = StubCodeDesc::desc_for(addr); if (d != NULL) { st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin())); d->print_on(st); st->cr(); return; } if (StubRoutines::contains(addr)) { st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) " "stub routine", addr); return; } // the InlineCacheBuffer is using stubs generated into a buffer blob if (InlineCacheBuffer::contains(addr)) { st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr); return; } VtableStub* v = VtableStubs::stub_containing(addr); if (v != NULL) { st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point())); v->print_on(st); st->cr(); return; } } nmethod* nm = b->as_nmethod_or_null(); if (nm != NULL) { ResourceMark rm; st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT, addr, (int)(addr - nm->entry_point()), nm); if (verbose) { st->print(" for "); nm->method()->print_value_on(st); } st->cr(); nm->print_nmethod(verbose); return; } st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin())); b->print_on(st); return; } if (Universe::heap()->is_in(addr)) { HeapWord* p = Universe::heap()->block_start(addr); bool print = false; // If we couldn't find it it just may mean that heap wasn't parseable // See if we were just given an oop directly if (p != NULL && Universe::heap()->block_is_obj(p)) { print = true; } else if (p == NULL && ((oopDesc*)addr)->is_oop()) { p = (HeapWord*) addr; print = true; } if (print) { if (p == (HeapWord*) addr) { st->print_cr(INTPTR_FORMAT " is an oop", addr); } else { st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p); } oop(p)->print_on(st); return; } } else { if (Universe::heap()->is_in_reserved(addr)) { st->print_cr(INTPTR_FORMAT " is an unallocated location " "in the heap", addr); return; } } if (JNIHandles::is_global_handle((jobject) addr)) { st->print_cr(INTPTR_FORMAT " is a global jni handle", addr); return; } if (JNIHandles::is_weak_global_handle((jobject) addr)) { st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr); return; } #ifndef PRODUCT // we don't keep the block list in product mode if (JNIHandleBlock::any_contains((jobject) addr)) { st->print_cr(INTPTR_FORMAT " is a local jni handle", addr); return; } #endif for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) { // Check for privilege stack if (thread->privileged_stack_top() != NULL && thread->privileged_stack_top()->contains(addr)) { st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack " "for thread: " INTPTR_FORMAT, addr, thread); if (verbose) thread->print_on(st); return; } // If the addr is a java thread print information about that. if (addr == (address)thread) { if (verbose) { thread->print_on(st); } else { st->print_cr(INTPTR_FORMAT " is a thread", addr); } return; } // If the addr is in the stack region for this thread then report that // and print thread info if (thread->stack_base() >= addr && addr > (thread->stack_base() - thread->stack_size())) { st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: " INTPTR_FORMAT, addr, thread); if (verbose) thread->print_on(st); return; } } // Check if in metaspace and print types that have vptrs (only method now) if (Metaspace::contains(addr)) { if (Method::has_method_vptr((const void*)addr)) { ((Method*)addr)->print_value_on(st); st->cr(); } else { // Use addr->print() from the debugger instead (not here) st->print_cr(INTPTR_FORMAT " is pointing into metadata", addr); } return; } // Try an OS specific find if (os::find(addr, st)) { return; } st->print_cr(INTPTR_FORMAT " is an unknown value", addr); } // Looks like all platforms except IA64 can use the same function to check // if C stack is walkable beyond current frame. The check for fp() is not // necessary on Sparc, but it's harmless. bool os::is_first_C_frame(frame* fr) { #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32) // On IA64 we have to check if the callers bsp is still valid // (i.e. within the register stack bounds). // Notice: this only works for threads created by the VM and only if // we walk the current stack!!! If we want to be able to walk // arbitrary other threads, we'll have to somehow store the thread // object in the frame. Thread *thread = Thread::current(); if ((address)fr->fp() <= thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) { // This check is a little hacky, because on Linux the first C // frame's ('start_thread') register stack frame starts at // "register_stack_base + 0x48" while on HPUX, the first C frame's // ('__pthread_bound_body') register stack frame seems to really // start at "register_stack_base". return true; } else { return false; } #elif defined(IA64) && defined(_WIN32) return true; #else // Load up sp, fp, sender sp and sender fp, check for reasonable values. // Check usp first, because if that's bad the other accessors may fault // on some architectures. Ditto ufp second, etc. uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1); // sp on amd can be 32 bit aligned. uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1); uintptr_t usp = (uintptr_t)fr->sp(); if ((usp & sp_align_mask) != 0) return true; uintptr_t ufp = (uintptr_t)fr->fp(); if ((ufp & fp_align_mask) != 0) return true; uintptr_t old_sp = (uintptr_t)fr->sender_sp(); if ((old_sp & sp_align_mask) != 0) return true; if (old_sp == 0 || old_sp == (uintptr_t)-1) return true; uintptr_t old_fp = (uintptr_t)fr->link(); if ((old_fp & fp_align_mask) != 0) return true; if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true; // stack grows downwards; if old_fp is below current fp or if the stack // frame is too large, either the stack is corrupted or fp is not saved // on stack (i.e. on x86, ebp may be used as general register). The stack // is not walkable beyond current frame. if (old_fp < ufp) return true; if (old_fp - ufp > 64 * K) return true; return false; #endif } #ifdef ASSERT extern "C" void test_random() { const double m = 2147483647; double mean = 0.0, variance = 0.0, t; long reps = 10000; unsigned long seed = 1; tty->print_cr("seed %ld for %ld repeats...", seed, reps); os::init_random(seed); long num; for (int k = 0; k < reps; k++) { num = os::random(); double u = (double)num / m; assert(u >= 0.0 && u <= 1.0, "bad random number!"); // calculate mean and variance of the random sequence mean += u; variance += (u*u); } mean /= reps; variance /= (reps - 1); assert(num == 1043618065, "bad seed"); tty->print_cr("mean of the 1st 10000 numbers: %f", mean); tty->print_cr("variance of the 1st 10000 numbers: %f", variance); const double eps = 0.0001; t = fabsd(mean - 0.5018); assert(t < eps, "bad mean"); t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355; assert(t < eps, "bad variance"); } #endif // Set up the boot classpath. char* os::format_boot_path(const char* format_string, const char* home, int home_len, char fileSep, char pathSep) { assert((fileSep == '/' && pathSep == ':') || (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars"); // Scan the format string to determine the length of the actual // boot classpath, and handle platform dependencies as well. int formatted_path_len = 0; const char* p; for (p = format_string; *p != 0; ++p) { if (*p == '%') formatted_path_len += home_len - 1; ++formatted_path_len; } char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal); if (formatted_path == NULL) { return NULL; } // Create boot classpath from format, substituting separator chars and // java home directory. char* q = formatted_path; for (p = format_string; *p != 0; ++p) { switch (*p) { case '%': strcpy(q, home); q += home_len; break; case '/': *q++ = fileSep; break; case ':': *q++ = pathSep; break; default: *q++ = *p; } } *q = '\0'; assert((q - formatted_path) == formatted_path_len, "formatted_path size botched"); return formatted_path; } bool os::set_boot_path(char fileSep, char pathSep) { const char* home = Arguments::get_java_home(); int home_len = (int)strlen(home); static const char* meta_index_dir_format = "%/lib/"; static const char* meta_index_format = "%/lib/meta-index"; char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep); if (meta_index == NULL) return false; char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep); if (meta_index_dir == NULL) return false; Arguments::set_meta_index_path(meta_index, meta_index_dir); // Any modification to the JAR-file list, for the boot classpath must be // aligned with install/install/make/common/Pack.gmk. Note: boot class // path class JARs, are stripped for StackMapTable to reduce download size. static const char classpath_format[] = "%/lib/resources.jar:" "%/lib/rt.jar:" "%/lib/sunrsasign.jar:" "%/lib/jsse.jar:" "%/lib/jce.jar:" "%/lib/charsets.jar:" "%/lib/jfr.jar:" "%/classes"; char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep); if (sysclasspath == NULL) return false; Arguments::set_sysclasspath(sysclasspath); return true; } /* * Splits a path, based on its separator, the number of * elements is returned back in n. * It is the callers responsibility to: * a> check the value of n, and n may be 0. * b> ignore any empty path elements * c> free up the data. */ char** os::split_path(const char* path, int* n) { *n = 0; if (path == NULL || strlen(path) == 0) { return NULL; } const char psepchar = *os::path_separator(); char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal); if (inpath == NULL) { return NULL; } strcpy(inpath, path); int count = 1; char* p = strchr(inpath, psepchar); // Get a count of elements to allocate memory while (p != NULL) { count++; p++; p = strchr(p, psepchar); } char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal); if (opath == NULL) { return NULL; } // do the actual splitting p = inpath; for (int i = 0 ; i < count ; i++) { size_t len = strcspn(p, os::path_separator()); if (len > JVM_MAXPATHLEN) { return NULL; } // allocate the string and add terminator storage char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal); if (s == NULL) { return NULL; } strncpy(s, p, len); s[len] = '\0'; opath[i] = s; p += len + 1; } FREE_C_HEAP_ARRAY(char, inpath, mtInternal); *n = count; return opath; } void os::set_memory_serialize_page(address page) { int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64); _mem_serialize_page = (volatile int32_t *)page; // We initialize the serialization page shift count here // We assume a cache line size of 64 bytes assert(SerializePageShiftCount == count, "thread size changed, fix SerializePageShiftCount constant"); set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t))); } static volatile intptr_t SerializePageLock = 0; // This method is called from signal handler when SIGSEGV occurs while the current // thread tries to store to the "read-only" memory serialize page during state // transition. void os::block_on_serialize_page_trap() { if (TraceSafepoint) { tty->print_cr("Block until the serialize page permission restored"); } // When VMThread is holding the SerializePageLock during modifying the // access permission of the memory serialize page, the following call // will block until the permission of that page is restored to rw. // Generally, it is unsafe to manipulate locks in signal handlers, but in // this case, it's OK as the signal is synchronous and we know precisely when // it can occur. Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page"); Thread::muxRelease(&SerializePageLock); } // Serialize all thread state variables void os::serialize_thread_states() { // On some platforms such as Solaris & Linux, the time duration of the page // permission restoration is observed to be much longer than expected due to // scheduler starvation problem etc. To avoid the long synchronization // time and expensive page trap spinning, 'SerializePageLock' is used to block // the mutator thread if such case is encountered. See bug 6546278 for details. Thread::muxAcquire(&SerializePageLock, "serialize_thread_states"); os::protect_memory((char *)os::get_memory_serialize_page(), os::vm_page_size(), MEM_PROT_READ); os::protect_memory((char *)os::get_memory_serialize_page(), os::vm_page_size(), MEM_PROT_RW); Thread::muxRelease(&SerializePageLock); } // Returns true if the current stack pointer is above the stack shadow // pages, false otherwise. bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) { assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check"); address sp = current_stack_pointer(); // Check if we have StackShadowPages above the yellow zone. This parameter // is dependent on the depth of the maximum VM call stack possible from // the handler for stack overflow. 'instanceof' in the stack overflow // handler or a println uses at least 8k stack of VM and native code // respectively. const int framesize_in_bytes = Interpreter::size_top_interpreter_activation(method()) * wordSize; int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages) * vm_page_size()) + framesize_in_bytes; // The very lower end of the stack address stack_limit = thread->stack_base() - thread->stack_size(); return (sp > (stack_limit + reserved_area)); } size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) { assert(min_pages > 0, "sanity"); if (UseLargePages) { const size_t max_page_size = region_size / min_pages; for (size_t i = 0; _page_sizes[i] != 0; ++i) { const size_t page_size = _page_sizes[i]; if (page_size <= max_page_size) { if (!must_be_aligned || is_size_aligned(region_size, page_size)) { return page_size; } } } } return vm_page_size(); } size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) { return page_size_for_region(region_size, min_pages, true); } size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) { return page_size_for_region(region_size, min_pages, false); } #ifndef PRODUCT void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) { if (TracePageSizes) { tty->print("%s: ", str); for (int i = 0; i < count; ++i) { tty->print(" " SIZE_FORMAT, page_sizes[i]); } tty->cr(); } } void os::trace_page_sizes(const char* str, const size_t region_min_size, const size_t region_max_size, const size_t page_size, const char* base, const size_t size) { if (TracePageSizes) { tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT " size=" SIZE_FORMAT, str, region_min_size, region_max_size, page_size, base, size); } } #endif // #ifndef PRODUCT // This is the working definition of a server class machine: // >= 2 physical CPU's and >=2GB of memory, with some fuzz // because the graphics memory (?) sometimes masks physical memory. // If you want to change the definition of a server class machine // on some OS or platform, e.g., >=4GB on Windohs platforms, // then you'll have to parameterize this method based on that state, // as was done for logical processors here, or replicate and // specialize this method for each platform. (Or fix os to have // some inheritance structure and use subclassing. Sigh.) // If you want some platform to always or never behave as a server // class machine, change the setting of AlwaysActAsServerClassMachine // and NeverActAsServerClassMachine in globals*.hpp. bool os::is_server_class_machine() { // First check for the early returns if (NeverActAsServerClassMachine) { return false; } if (AlwaysActAsServerClassMachine) { return true; } // Then actually look at the machine bool result = false; const unsigned int server_processors = 2; const julong server_memory = 2UL * G; // We seem not to get our full complement of memory. // We allow some part (1/8?) of the memory to be "missing", // based on the sizes of DIMMs, and maybe graphics cards. const julong missing_memory = 256UL * M; /* Is this a server class machine? */ if ((os::active_processor_count() >= (int)server_processors) && (os::physical_memory() >= (server_memory - missing_memory))) { const unsigned int logical_processors = VM_Version::logical_processors_per_package(); if (logical_processors > 1) { const unsigned int physical_packages = os::active_processor_count() / logical_processors; if (physical_packages > server_processors) { result = true; } } else { result = true; } } return result; } void os::initialize_initial_active_processor_count() { assert(_initial_active_processor_count == 0, "Initial active processor count already set."); _initial_active_processor_count = active_processor_count(); } void os::SuspendedThreadTask::run() { assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this"); internal_do_task(); _done = true; } bool os::create_stack_guard_pages(char* addr, size_t bytes) { return os::pd_create_stack_guard_pages(addr, bytes); } char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) { char* result = pd_reserve_memory(bytes, addr, alignment_hint); if (result != NULL) { MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); } return result; } char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, MEMFLAGS flags) { char* result = pd_reserve_memory(bytes, addr, alignment_hint); if (result != NULL) { MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); MemTracker::record_virtual_memory_type((address)result, flags); } return result; } char* os::attempt_reserve_memory_at(size_t bytes, char* addr) { char* result = pd_attempt_reserve_memory_at(bytes, addr); if (result != NULL) { MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC); } return result; } void os::split_reserved_memory(char *base, size_t size, size_t split, bool realloc) { pd_split_reserved_memory(base, size, split, realloc); } bool os::commit_memory(char* addr, size_t bytes, bool executable) { bool res = pd_commit_memory(addr, bytes, executable); if (res) { MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC); } return res; } bool os::commit_memory(char* addr, size_t size, size_t alignment_hint, bool executable) { bool res = os::pd_commit_memory(addr, size, alignment_hint, executable); if (res) { MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC); } return res; } void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable, const char* mesg) { pd_commit_memory_or_exit(addr, bytes, executable, mesg); MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC); } void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint, bool executable, const char* mesg) { os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg); MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC); } bool os::uncommit_memory(char* addr, size_t bytes) { bool res; if (MemTracker::tracking_level() > NMT_minimal) { Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker(); res = pd_uncommit_memory(addr, bytes); if (res) { tkr.record((address)addr, bytes); } } else { res = pd_uncommit_memory(addr, bytes); } return res; } bool os::release_memory(char* addr, size_t bytes) { bool res; if (MemTracker::tracking_level() > NMT_minimal) { Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); res = pd_release_memory(addr, bytes); if (res) { tkr.record((address)addr, bytes); } } else { res = pd_release_memory(addr, bytes); } return res; } void os::pretouch_memory(char* start, char* end) { for (volatile char *p = start; p < end; p += os::vm_page_size()) { *p = 0; } } char* os::map_memory(int fd, const char* file_name, size_t file_offset, char *addr, size_t bytes, bool read_only, bool allow_exec) { char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec); if (result != NULL) { MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC); } return result; } char* os::remap_memory(int fd, const char* file_name, size_t file_offset, char *addr, size_t bytes, bool read_only, bool allow_exec) { return pd_remap_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec); } bool os::unmap_memory(char *addr, size_t bytes) { bool result; if (MemTracker::tracking_level() > NMT_minimal) { Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); result = pd_unmap_memory(addr, bytes); if (result) { tkr.record((address)addr, bytes); } } else { result = pd_unmap_memory(addr, bytes); } return result; } void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) { pd_free_memory(addr, bytes, alignment_hint); } void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) { pd_realign_memory(addr, bytes, alignment_hint); } #ifndef TARGET_OS_FAMILY_windows /* try to switch state from state "from" to state "to" * returns the state set after the method is complete */ os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from, os::SuspendResume::State to) { os::SuspendResume::State result = (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from); if (result == from) { // success return to; } return result; } #endif /////////////// Unit tests /////////////// #ifndef PRODUCT #define assert_eq(a,b) assert(a == b, err_msg(SIZE_FORMAT " != " SIZE_FORMAT, a, b)) class TestOS : AllStatic { static size_t small_page_size() { return os::vm_page_size(); } static size_t large_page_size() { const size_t large_page_size_example = 4 * M; return os::page_size_for_region_aligned(large_page_size_example, 1); } static void test_page_size_for_region_aligned() { if (UseLargePages) { const size_t small_page = small_page_size(); const size_t large_page = large_page_size(); if (large_page > small_page) { size_t num_small_pages_in_large = large_page / small_page; size_t page = os::page_size_for_region_aligned(large_page, num_small_pages_in_large); assert_eq(page, small_page); } } } static void test_page_size_for_region_alignment() { if (UseLargePages) { const size_t small_page = small_page_size(); const size_t large_page = large_page_size(); if (large_page > small_page) { const size_t unaligned_region = large_page + 17; size_t page = os::page_size_for_region_aligned(unaligned_region, 1); assert_eq(page, small_page); const size_t num_pages = 5; const size_t aligned_region = large_page * num_pages; page = os::page_size_for_region_aligned(aligned_region, num_pages); assert_eq(page, large_page); } } } static void test_page_size_for_region_unaligned() { if (UseLargePages) { // Given exact page size, should return that page size. for (size_t i = 0; os::_page_sizes[i] != 0; i++) { size_t expected = os::_page_sizes[i]; size_t actual = os::page_size_for_region_unaligned(expected, 1); assert_eq(expected, actual); } // Given slightly larger size than a page size, return the page size. for (size_t i = 0; os::_page_sizes[i] != 0; i++) { size_t expected = os::_page_sizes[i]; size_t actual = os::page_size_for_region_unaligned(expected + 17, 1); assert_eq(expected, actual); } // Given a slightly smaller size than a page size, // return the next smaller page size. if (os::_page_sizes[1] > os::_page_sizes[0]) { size_t expected = os::_page_sizes[0]; size_t actual = os::page_size_for_region_unaligned(os::_page_sizes[1] - 17, 1); assert_eq(actual, expected); } // Return small page size for values less than a small page. size_t small_page = small_page_size(); size_t actual = os::page_size_for_region_unaligned(small_page - 17, 1); assert_eq(small_page, actual); } } public: static void run_tests() { test_page_size_for_region_aligned(); test_page_size_for_region_alignment(); test_page_size_for_region_unaligned(); } }; void TestOS_test() { TestOS::run_tests(); } #endif // PRODUCT