JDK14/Java14源码在线阅读
/*
* Copyright (c) 1997, 2019, 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.
*
*/
// Must be at least Windows Vista or Server 2008 to use InitOnceExecuteOnce
#define _WIN32_WINNT 0x0600
// 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 "logging/logStream.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/filemap.hpp"
#include "oops/oop.inline.hpp"
#include "os_share_windows.hpp"
#include "os_windows.inline.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/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/timer.hpp"
#include "runtime/vm_version.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/growableArray.hpp"
#include "utilities/macros.hpp"
#include "utilities/vmError.hpp"
#include "symbolengine.hpp"
#include "windbghelp.hpp"
#ifdef _DEBUG
#include <crtdbg.h>
#endif
#include <windows.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/timeb.h>
#include <objidl.h>
#include <shlobj.h>
#include <malloc.h>
#include <signal.h>
#include <direct.h>
#include <errno.h>
#include <fcntl.h>
#include <io.h>
#include <process.h> // For _beginthreadex(), _endthreadex()
#include <imagehlp.h> // For os::dll_address_to_function_name
// for enumerating dll libraries
#include <vdmdbg.h>
#include <psapi.h>
#include <mmsystem.h>
#include <winsock2.h>
// for timer info max values which include all bits
#define ALL_64_BITS CONST64(-1)
// For DLL loading/load error detection
// Values of PE COFF
#define IMAGE_FILE_PTR_TO_SIGNATURE 0x3c
#define IMAGE_FILE_SIGNATURE_LENGTH 4
static HANDLE main_process;
static HANDLE main_thread;
static int main_thread_id;
static FILETIME process_creation_time;
static FILETIME process_exit_time;
static FILETIME process_user_time;
static FILETIME process_kernel_time;
#ifdef _M_AMD64
#define __CPU__ amd64
#else
#define __CPU__ i486
#endif
#if INCLUDE_AOT
PVOID topLevelVectoredExceptionHandler = NULL;
LONG WINAPI topLevelVectoredExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo);
#endif
// save DLL module handle, used by GetModuleFileName
HINSTANCE vm_lib_handle;
BOOL WINAPI DllMain(HINSTANCE hinst, DWORD reason, LPVOID reserved) {
switch (reason) {
case DLL_PROCESS_ATTACH:
vm_lib_handle = hinst;
if (ForceTimeHighResolution) {
timeBeginPeriod(1L);
}
WindowsDbgHelp::pre_initialize();
SymbolEngine::pre_initialize();
break;
case DLL_PROCESS_DETACH:
if (ForceTimeHighResolution) {
timeEndPeriod(1L);
}
#if INCLUDE_AOT
if (topLevelVectoredExceptionHandler != NULL) {
RemoveVectoredExceptionHandler(topLevelVectoredExceptionHandler);
topLevelVectoredExceptionHandler = NULL;
}
#endif
break;
default:
break;
}
return true;
}
static inline double fileTimeAsDouble(FILETIME* time) {
const double high = (double) ((unsigned int) ~0);
const double split = 10000000.0;
double result = (time->dwLowDateTime / split) +
time->dwHighDateTime * (high/split);
return result;
}
// Implementation of os
bool os::unsetenv(const char* name) {
assert(name != NULL, "Null pointer");
return (SetEnvironmentVariable(name, NULL) == TRUE);
}
// No setuid programs under Windows.
bool os::have_special_privileges() {
return false;
}
// This method is a periodic task to check for misbehaving JNI applications
// under CheckJNI, we can add any periodic checks here.
// For Windows at the moment does nothing
void os::run_periodic_checks() {
return;
}
// previous UnhandledExceptionFilter, if there is one
static LPTOP_LEVEL_EXCEPTION_FILTER prev_uef_handler = NULL;
LONG WINAPI Handle_FLT_Exception(struct _EXCEPTION_POINTERS* exceptionInfo);
void os::init_system_properties_values() {
// sysclasspath, java_home, dll_dir
{
char *home_path;
char *dll_path;
char *pslash;
const char *bin = "\\bin";
char home_dir[MAX_PATH + 1];
char *alt_home_dir = ::getenv("_ALT_JAVA_HOME_DIR");
if (alt_home_dir != NULL) {
strncpy(home_dir, alt_home_dir, MAX_PATH + 1);
home_dir[MAX_PATH] = '\0';
} else {
os::jvm_path(home_dir, sizeof(home_dir));
// Found the full path to jvm.dll.
// Now cut the path to <java_home>/jre if we can.
*(strrchr(home_dir, '\\')) = '\0'; // get rid of \jvm.dll
pslash = strrchr(home_dir, '\\');
if (pslash != NULL) {
*pslash = '\0'; // get rid of \{client|server}
pslash = strrchr(home_dir, '\\');
if (pslash != NULL) {
*pslash = '\0'; // get rid of \bin
}
}
}
home_path = NEW_C_HEAP_ARRAY(char, strlen(home_dir) + 1, mtInternal);
strcpy(home_path, home_dir);
Arguments::set_java_home(home_path);
FREE_C_HEAP_ARRAY(char, home_path);
dll_path = NEW_C_HEAP_ARRAY(char, strlen(home_dir) + strlen(bin) + 1,
mtInternal);
strcpy(dll_path, home_dir);
strcat(dll_path, bin);
Arguments::set_dll_dir(dll_path);
FREE_C_HEAP_ARRAY(char, dll_path);
if (!set_boot_path('\\', ';')) {
vm_exit_during_initialization("Failed setting boot class path.", NULL);
}
}
// library_path
#define EXT_DIR "\\lib\\ext"
#define BIN_DIR "\\bin"
#define PACKAGE_DIR "\\Sun\\Java"
{
// Win32 library search order (See the documentation for LoadLibrary):
//
// 1. The directory from which application is loaded.
// 2. The system wide Java Extensions directory (Java only)
// 3. System directory (GetSystemDirectory)
// 4. Windows directory (GetWindowsDirectory)
// 5. The PATH environment variable
// 6. The current directory
char *library_path;
char tmp[MAX_PATH];
char *path_str = ::getenv("PATH");
library_path = NEW_C_HEAP_ARRAY(char, MAX_PATH * 5 + sizeof(PACKAGE_DIR) +
sizeof(BIN_DIR) + (path_str ? strlen(path_str) : 0) + 10, mtInternal);
library_path[0] = '\0';
GetModuleFileName(NULL, tmp, sizeof(tmp));
*(strrchr(tmp, '\\')) = '\0';
strcat(library_path, tmp);
GetWindowsDirectory(tmp, sizeof(tmp));
strcat(library_path, ";");
strcat(library_path, tmp);
strcat(library_path, PACKAGE_DIR BIN_DIR);
GetSystemDirectory(tmp, sizeof(tmp));
strcat(library_path, ";");
strcat(library_path, tmp);
GetWindowsDirectory(tmp, sizeof(tmp));
strcat(library_path, ";");
strcat(library_path, tmp);
if (path_str) {
strcat(library_path, ";");
strcat(library_path, path_str);
}
strcat(library_path, ";.");
Arguments::set_library_path(library_path);
FREE_C_HEAP_ARRAY(char, library_path);
}
// Default extensions directory
{
char path[MAX_PATH];
char buf[2 * MAX_PATH + 2 * sizeof(EXT_DIR) + sizeof(PACKAGE_DIR) + 1];
GetWindowsDirectory(path, MAX_PATH);
sprintf(buf, "%s%s;%s%s%s", Arguments::get_java_home(), EXT_DIR,
path, PACKAGE_DIR, EXT_DIR);
Arguments::set_ext_dirs(buf);
}
#undef EXT_DIR
#undef BIN_DIR
#undef PACKAGE_DIR
#ifndef _WIN64
// set our UnhandledExceptionFilter and save any previous one
prev_uef_handler = SetUnhandledExceptionFilter(Handle_FLT_Exception);
#endif
// Done
return;
}
void os::breakpoint() {
DebugBreak();
}
// Invoked from the BREAKPOINT Macro
extern "C" void breakpoint() {
os::breakpoint();
}
// RtlCaptureStackBackTrace Windows API may not exist prior to Windows XP.
// So far, this method is only used by Native Memory Tracking, which is
// only supported on Windows XP or later.
//
int os::get_native_stack(address* stack, int frames, int toSkip) {
int captured = RtlCaptureStackBackTrace(toSkip + 1, frames, (PVOID*)stack, NULL);
for (int index = captured; index < frames; index ++) {
stack[index] = NULL;
}
return captured;
}
// os::current_stack_base()
//
// Returns the base of the stack, which is the stack's
// starting address. This function must be called
// while running on the stack of the thread being queried.
address os::current_stack_base() {
MEMORY_BASIC_INFORMATION minfo;
address stack_bottom;
size_t stack_size;
VirtualQuery(&minfo, &minfo, sizeof(minfo));
stack_bottom = (address)minfo.AllocationBase;
stack_size = minfo.RegionSize;
// Add up the sizes of all the regions with the same
// AllocationBase.
while (1) {
VirtualQuery(stack_bottom+stack_size, &minfo, sizeof(minfo));
if (stack_bottom == (address)minfo.AllocationBase) {
stack_size += minfo.RegionSize;
} else {
break;
}
}
return stack_bottom + stack_size;
}
size_t os::current_stack_size() {
size_t sz;
MEMORY_BASIC_INFORMATION minfo;
VirtualQuery(&minfo, &minfo, sizeof(minfo));
sz = (size_t)os::current_stack_base() - (size_t)minfo.AllocationBase;
return sz;
}
bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) {
MEMORY_BASIC_INFORMATION minfo;
committed_start = NULL;
committed_size = 0;
address top = start + size;
const address start_addr = start;
while (start < top) {
VirtualQuery(start, &minfo, sizeof(minfo));
if ((minfo.State & MEM_COMMIT) == 0) { // not committed
if (committed_start != NULL) {
break;
}
} else { // committed
if (committed_start == NULL) {
committed_start = start;
}
size_t offset = start - (address)minfo.BaseAddress;
committed_size += minfo.RegionSize - offset;
}
start = (address)minfo.BaseAddress + minfo.RegionSize;
}
if (committed_start == NULL) {
assert(committed_size == 0, "Sanity");
return false;
} else {
assert(committed_start >= start_addr && committed_start < top, "Out of range");
// current region may go beyond the limit, trim to the limit
committed_size = MIN2(committed_size, size_t(top - committed_start));
return true;
}
}
struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
const struct tm* time_struct_ptr = localtime(clock);
if (time_struct_ptr != NULL) {
*res = *time_struct_ptr;
return res;
}
return NULL;
}
struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
const struct tm* time_struct_ptr = gmtime(clock);
if (time_struct_ptr != NULL) {
*res = *time_struct_ptr;
return res;
}
return NULL;
}
LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo);
// Thread start routine for all newly created threads
static unsigned __stdcall thread_native_entry(Thread* thread) {
thread->record_stack_base_and_size();
// 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* osthr = thread->osthread();
assert(osthr->get_state() == RUNNABLE, "invalid os thread state");
if (UseNUMA) {
int lgrp_id = os::numa_get_group_id();
if (lgrp_id != -1) {
thread->set_lgrp_id(lgrp_id);
}
}
// Diagnostic code to investigate JDK-6573254
int res = 30115; // non-java thread
if (thread->is_Java_thread()) {
res = 20115; // java thread
}
log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ").", os::current_thread_id());
// Install a win32 structured exception handler around every thread created
// by VM, so VM can generate error dump when an exception occurred in non-
// Java thread (e.g. VM thread).
__try {
thread->call_run();
} __except(topLevelExceptionFilter(
(_EXCEPTION_POINTERS*)_exception_info())) {
// Nothing to do.
}
// Note: at this point the thread object may already have deleted itself.
// Do not dereference it from here on out.
log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ").", os::current_thread_id());
// One less thread is executing
// When the VMThread gets here, the main thread may have already exited
// which frees the CodeHeap containing the Atomic::add code
if (thread != VMThread::vm_thread() && VMThread::vm_thread() != NULL) {
Atomic::dec(&os::win32::_os_thread_count);
}
// Thread must not return from exit_process_or_thread(), but if it does,
// let it proceed to exit normally
return (unsigned)os::win32::exit_process_or_thread(os::win32::EPT_THREAD, res);
}
static OSThread* create_os_thread(Thread* thread, HANDLE thread_handle,
int thread_id) {
// Allocate the OSThread object
OSThread* osthread = new OSThread(NULL, NULL);
if (osthread == NULL) return NULL;
// Initialize the JDK library's interrupt event.
// This should really be done when OSThread is constructed,
// but there is no way for a constructor to report failure to
// allocate the event.
HANDLE interrupt_event = CreateEvent(NULL, true, false, NULL);
if (interrupt_event == NULL) {
delete osthread;
return NULL;
}
osthread->set_interrupt_event(interrupt_event);
// Store info on the Win32 thread into the OSThread
osthread->set_thread_handle(thread_handle);
osthread->set_thread_id(thread_id);
if (UseNUMA) {
int lgrp_id = os::numa_get_group_id();
if (lgrp_id != -1) {
thread->set_lgrp_id(lgrp_id);
}
}
// Initial thread state is INITIALIZED, not SUSPENDED
osthread->set_state(INITIALIZED);
return osthread;
}
bool os::create_attached_thread(JavaThread* thread) {
#ifdef ASSERT
thread->verify_not_published();
#endif
HANDLE thread_h;
if (!DuplicateHandle(main_process, GetCurrentThread(), GetCurrentProcess(),
&thread_h, THREAD_ALL_ACCESS, false, 0)) {
fatal("DuplicateHandle failed\n");
}
OSThread* osthread = create_os_thread(thread, thread_h,
(int)current_thread_id());
if (osthread == NULL) {
return false;
}
// Initial thread state is RUNNABLE
osthread->set_state(RUNNABLE);
thread->set_osthread(osthread);
log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ").",
os::current_thread_id());
return true;
}
bool os::create_main_thread(JavaThread* thread) {
#ifdef ASSERT
thread->verify_not_published();
#endif
if (_starting_thread == NULL) {
_starting_thread = create_os_thread(thread, main_thread, main_thread_id);
if (_starting_thread == NULL) {
return false;
}
}
// The primordial thread is runnable from the start)
_starting_thread->set_state(RUNNABLE);
thread->set_osthread(_starting_thread);
return true;
}
// Helper function to trace _beginthreadex attributes,
// similar to os::Posix::describe_pthread_attr()
static char* describe_beginthreadex_attributes(char* buf, size_t buflen,
size_t stacksize, unsigned initflag) {
stringStream ss(buf, buflen);
if (stacksize == 0) {
ss.print("stacksize: default, ");
} else {
ss.print("stacksize: " SIZE_FORMAT "k, ", stacksize / 1024);
}
ss.print("flags: ");
#define PRINT_FLAG(f) if (initflag & f) ss.print( #f " ");
#define ALL(X) \
X(CREATE_SUSPENDED) \
X(STACK_SIZE_PARAM_IS_A_RESERVATION)
ALL(PRINT_FLAG)
#undef ALL
#undef PRINT_FLAG
return buf;
}
// Allocate and initialize a new OSThread
bool os::create_thread(Thread* thread, ThreadType thr_type,
size_t stack_size) {
unsigned thread_id;
// Allocate the OSThread object
OSThread* osthread = new OSThread(NULL, NULL);
if (osthread == NULL) {
return false;
}
// Initialize the JDK library's interrupt event.
// This should really be done when OSThread is constructed,
// but there is no way for a constructor to report failure to
// allocate the event.
HANDLE interrupt_event = CreateEvent(NULL, true, false, NULL);
if (interrupt_event == NULL) {
delete osthread;
return false;
}
osthread->set_interrupt_event(interrupt_event);
// We don't call set_interrupted(false) as it will trip the assert in there
// as we are not operating on the current thread. We don't need to call it
// because the initial state is already correct.
thread->set_osthread(osthread);
if (stack_size == 0) {
switch (thr_type) {
case os::java_thread:
// Java threads use ThreadStackSize which default value can be changed with the flag -Xss
if (JavaThread::stack_size_at_create() > 0) {
stack_size = JavaThread::stack_size_at_create();
}
break;
case os::compiler_thread:
if (CompilerThreadStackSize > 0) {
stack_size = (size_t)(CompilerThreadStackSize * K);
break;
} // else fall through:
// use VMThreadStackSize if CompilerThreadStackSize is not defined
case os::vm_thread:
case os::pgc_thread:
case os::cgc_thread:
case os::watcher_thread:
if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
break;
}
}
// Create the Win32 thread
//
// Contrary to what MSDN document says, "stack_size" in _beginthreadex()
// does not specify stack size. Instead, it specifies the size of
// initially committed space. The stack size is determined by
// PE header in the executable. If the committed "stack_size" is larger
// than default value in the PE header, the stack is rounded up to the
// nearest multiple of 1MB. For example if the launcher has default
// stack size of 320k, specifying any size less than 320k does not
// affect the actual stack size at all, it only affects the initial
// commitment. On the other hand, specifying 'stack_size' larger than
// default value may cause significant increase in memory usage, because
// not only the stack space will be rounded up to MB, but also the
// entire space is committed upfront.
//
// Finally Windows XP added a new flag 'STACK_SIZE_PARAM_IS_A_RESERVATION'
// for CreateThread() that can treat 'stack_size' as stack size. However we
// are not supposed to call CreateThread() directly according to MSDN
// document because JVM uses C runtime library. The good news is that the
// flag appears to work with _beginthredex() as well.
const unsigned initflag = CREATE_SUSPENDED | STACK_SIZE_PARAM_IS_A_RESERVATION;
HANDLE thread_handle =
(HANDLE)_beginthreadex(NULL,
(unsigned)stack_size,
(unsigned (__stdcall *)(void*)) thread_native_entry,
thread,
initflag,
&thread_id);
char buf[64];
if (thread_handle != NULL) {
log_info(os, thread)("Thread started (tid: %u, attributes: %s)",
thread_id, describe_beginthreadex_attributes(buf, sizeof(buf), stack_size, initflag));
} else {
log_warning(os, thread)("Failed to start thread - _beginthreadex failed (%s) for attributes: %s.",
os::errno_name(errno), describe_beginthreadex_attributes(buf, sizeof(buf), stack_size, initflag));
// Log some OS information which might explain why creating the thread failed.
log_info(os, thread)("Number of threads approx. running in the VM: %d", Threads::number_of_threads());
LogStream st(Log(os, thread)::info());
os::print_memory_info(&st);
}
if (thread_handle == NULL) {
// Need to clean up stuff we've allocated so far
thread->set_osthread(NULL);
delete osthread;
return false;
}
Atomic::inc(&os::win32::_os_thread_count);
// Store info on the Win32 thread into the OSThread
osthread->set_thread_handle(thread_handle);
osthread->set_thread_id(thread_id);
// Initial thread state is INITIALIZED, not SUSPENDED
osthread->set_state(INITIALIZED);
// The thread is returned suspended (in state INITIALIZED), and is started higher up in the call chain
return true;
}
// Free Win32 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");
CloseHandle(osthread->thread_handle());
delete osthread;
}
static jlong first_filetime;
static jlong initial_performance_count;
static jlong performance_frequency;
jlong as_long(LARGE_INTEGER x) {
jlong result = 0; // initialization to avoid warning
set_high(&result, x.HighPart);
set_low(&result, x.LowPart);
return result;
}
jlong os::elapsed_counter() {
LARGE_INTEGER count;
QueryPerformanceCounter(&count);
return as_long(count) - initial_performance_count;
}
jlong os::elapsed_frequency() {
return performance_frequency;
}
julong os::available_memory() {
return win32::available_memory();
}
julong os::win32::available_memory() {
// Use GlobalMemoryStatusEx() because GlobalMemoryStatus() may return incorrect
// value if total memory is larger than 4GB
MEMORYSTATUSEX ms;
ms.dwLength = sizeof(ms);
GlobalMemoryStatusEx(&ms);
return (julong)ms.ullAvailPhys;
}
julong os::physical_memory() {
return win32::physical_memory();
}
bool os::has_allocatable_memory_limit(julong* limit) {
MEMORYSTATUSEX ms;
ms.dwLength = sizeof(ms);
GlobalMemoryStatusEx(&ms);
#ifdef _LP64
*limit = (julong)ms.ullAvailVirtual;
return true;
#else
// Limit to 1400m because of the 2gb address space wall
*limit = MIN2((julong)1400*M, (julong)ms.ullAvailVirtual);
return true;
#endif
}
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;
}
DWORD_PTR lpProcessAffinityMask = 0;
DWORD_PTR lpSystemAffinityMask = 0;
int proc_count = processor_count();
if (proc_count <= sizeof(UINT_PTR) * BitsPerByte &&
GetProcessAffinityMask(GetCurrentProcess(), &lpProcessAffinityMask, &lpSystemAffinityMask)) {
// Nof active processors is number of bits in process affinity mask
int bitcount = 0;
while (lpProcessAffinityMask != 0) {
lpProcessAffinityMask = lpProcessAffinityMask & (lpProcessAffinityMask-1);
bitcount++;
}
return bitcount;
} else {
return proc_count;
}
}
uint os::processor_id() {
return (uint)GetCurrentProcessorNumber();
}
void os::set_native_thread_name(const char *name) {
// See: http://msdn.microsoft.com/en-us/library/xcb2z8hs.aspx
//
// Note that unfortunately this only works if the process
// is already attached to a debugger; debugger must observe
// the exception below to show the correct name.
// If there is no debugger attached skip raising the exception
if (!IsDebuggerPresent()) {
return;
}
const DWORD MS_VC_EXCEPTION = 0x406D1388;
struct {
DWORD dwType; // must be 0x1000
LPCSTR szName; // pointer to name (in user addr space)
DWORD dwThreadID; // thread ID (-1=caller thread)
DWORD dwFlags; // reserved for future use, must be zero
} info;
info.dwType = 0x1000;
info.szName = name;
info.dwThreadID = -1;
info.dwFlags = 0;
__try {
RaiseException (MS_VC_EXCEPTION, 0, sizeof(info)/sizeof(DWORD), (const ULONG_PTR*)&info );
} __except(EXCEPTION_EXECUTE_HANDLER) {}
}
bool os::bind_to_processor(uint processor_id) {
// Not yet implemented.
return false;
}
void os::win32::initialize_performance_counter() {
LARGE_INTEGER count;
QueryPerformanceFrequency(&count);
performance_frequency = as_long(count);
QueryPerformanceCounter(&count);
initial_performance_count = as_long(count);
}
double os::elapsedTime() {
return (double) elapsed_counter() / (double) elapsed_frequency();
}
// Windows format:
// The FILETIME structure is a 64-bit value representing the number of 100-nanosecond intervals since January 1, 1601.
// Java format:
// Java standards require the number of milliseconds since 1/1/1970
// Constant offset - calculated using offset()
static jlong _offset = 116444736000000000;
// Fake time counter for reproducible results when debugging
static jlong fake_time = 0;
#ifdef ASSERT
// Just to be safe, recalculate the offset in debug mode
static jlong _calculated_offset = 0;
static int _has_calculated_offset = 0;
jlong offset() {
if (_has_calculated_offset) return _calculated_offset;
SYSTEMTIME java_origin;
java_origin.wYear = 1970;
java_origin.wMonth = 1;
java_origin.wDayOfWeek = 0; // ignored
java_origin.wDay = 1;
java_origin.wHour = 0;
java_origin.wMinute = 0;
java_origin.wSecond = 0;
java_origin.wMilliseconds = 0;
FILETIME jot;
if (!SystemTimeToFileTime(&java_origin, &jot)) {
fatal("Error = %d\nWindows error", GetLastError());
}
_calculated_offset = jlong_from(jot.dwHighDateTime, jot.dwLowDateTime);
_has_calculated_offset = 1;
assert(_calculated_offset == _offset, "Calculated and constant time offsets must be equal");
return _calculated_offset;
}
#else
jlong offset() {
return _offset;
}
#endif
jlong windows_to_java_time(FILETIME wt) {
jlong a = jlong_from(wt.dwHighDateTime, wt.dwLowDateTime);
return (a - offset()) / 10000;
}
// Returns time ticks in (10th of micro seconds)
jlong windows_to_time_ticks(FILETIME wt) {
jlong a = jlong_from(wt.dwHighDateTime, wt.dwLowDateTime);
return (a - offset());
}
FILETIME java_to_windows_time(jlong l) {
jlong a = (l * 10000) + offset();
FILETIME result;
result.dwHighDateTime = high(a);
result.dwLowDateTime = low(a);
return result;
}
bool os::supports_vtime() { return true; }
double os::elapsedVTime() {
FILETIME created;
FILETIME exited;
FILETIME kernel;
FILETIME user;
if (GetThreadTimes(GetCurrentThread(), &created, &exited, &kernel, &user) != 0) {
// the resolution of windows_to_java_time() should be sufficient (ms)
return (double) (windows_to_java_time(kernel) + windows_to_java_time(user)) / MILLIUNITS;
} else {
return elapsedTime();
}
}
jlong os::javaTimeMillis() {
FILETIME wt;
GetSystemTimeAsFileTime(&wt);
return windows_to_java_time(wt);
}
void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
FILETIME wt;
GetSystemTimeAsFileTime(&wt);
jlong ticks = windows_to_time_ticks(wt); // 10th of micros
jlong secs = jlong(ticks / 10000000); // 10000 * 1000
seconds = secs;
nanos = jlong(ticks - (secs*10000000)) * 100;
}
jlong os::javaTimeNanos() {
LARGE_INTEGER current_count;
QueryPerformanceCounter(¤t_count);
double current = as_long(current_count);
double freq = performance_frequency;
jlong time = (jlong)((current/freq) * NANOSECS_PER_SEC);
return time;
}
void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
jlong freq = performance_frequency;
if (freq < NANOSECS_PER_SEC) {
// the performance counter is 64 bits and we will
// be multiplying it -- so no wrap in 64 bits
info_ptr->max_value = ALL_64_BITS;
} else if (freq > NANOSECS_PER_SEC) {
// use the max value the counter can reach to
// determine the max value which could be returned
julong max_counter = (julong)ALL_64_BITS;
info_ptr->max_value = (jlong)(max_counter / (freq / NANOSECS_PER_SEC));
} else {
// the performance counter is 64 bits and we will
// be using it directly -- so no wrap in 64 bits
info_ptr->max_value = ALL_64_BITS;
}
// using a counter, so no skipping
info_ptr->may_skip_backward = false;
info_ptr->may_skip_forward = false;
info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
}
char* os::local_time_string(char *buf, size_t buflen) {
SYSTEMTIME st;
GetLocalTime(&st);
jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond);
return buf;
}
bool os::getTimesSecs(double* process_real_time,
double* process_user_time,
double* process_system_time) {
HANDLE h_process = GetCurrentProcess();
FILETIME create_time, exit_time, kernel_time, user_time;
BOOL result = GetProcessTimes(h_process,
&create_time,
&exit_time,
&kernel_time,
&user_time);
if (result != 0) {
FILETIME wt;
GetSystemTimeAsFileTime(&wt);
jlong rtc_millis = windows_to_java_time(wt);
*process_real_time = ((double) rtc_millis) / ((double) MILLIUNITS);
*process_user_time =
(double) jlong_from(user_time.dwHighDateTime, user_time.dwLowDateTime) / (10 * MICROUNITS);
*process_system_time =
(double) jlong_from(kernel_time.dwHighDateTime, kernel_time.dwLowDateTime) / (10 * MICROUNITS);
return true;
} else {
return false;
}
}
void os::shutdown() {
// allow PerfMemory to attempt cleanup of any persistent resources
perfMemory_exit();
// 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();
}
}
static HANDLE dumpFile = NULL;
// Check if dump file can be created.
void os::check_dump_limit(char* buffer, size_t buffsz) {
bool status = true;
if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
jio_snprintf(buffer, buffsz, "CreateCoredumpOnCrash is disabled from command line");
status = false;
}
#ifndef ASSERT
if (!os::win32::is_windows_server() && FLAG_IS_DEFAULT(CreateCoredumpOnCrash)) {
jio_snprintf(buffer, buffsz, "Minidumps are not enabled by default on client versions of Windows");
status = false;
}
#endif
if (status) {
const char* cwd = get_current_directory(NULL, 0);
int pid = current_process_id();
if (cwd != NULL) {
jio_snprintf(buffer, buffsz, "%s\\hs_err_pid%u.mdmp", cwd, pid);
} else {
jio_snprintf(buffer, buffsz, ".\\hs_err_pid%u.mdmp", pid);
}
if (dumpFile == NULL &&
(dumpFile = CreateFile(buffer, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL))
== INVALID_HANDLE_VALUE) {
jio_snprintf(buffer, buffsz, "Failed to create minidump file (0x%x).", GetLastError());
status = false;
}
}
VMError::record_coredump_status(buffer, status);
}
void os::abort(bool dump_core, void* siginfo, const void* context) {
EXCEPTION_POINTERS ep;
MINIDUMP_EXCEPTION_INFORMATION mei;
MINIDUMP_EXCEPTION_INFORMATION* pmei;
HANDLE hProcess = GetCurrentProcess();
DWORD processId = GetCurrentProcessId();
MINIDUMP_TYPE dumpType;
shutdown();
if (!dump_core || dumpFile == NULL) {
if (dumpFile != NULL) {
CloseHandle(dumpFile);
}
win32::exit_process_or_thread(win32::EPT_PROCESS, 1);
}
dumpType = (MINIDUMP_TYPE)(MiniDumpWithFullMemory | MiniDumpWithHandleData |
MiniDumpWithFullMemoryInfo | MiniDumpWithThreadInfo | MiniDumpWithUnloadedModules);
if (siginfo != NULL && context != NULL) {
ep.ContextRecord = (PCONTEXT) context;
ep.ExceptionRecord = (PEXCEPTION_RECORD) siginfo;
mei.ThreadId = GetCurrentThreadId();
mei.ExceptionPointers = &ep;
pmei = &mei;
} else {
pmei = NULL;
}
// Older versions of dbghelp.dll (the one shipped with Win2003 for example) may not support all
// the dump types we really want. If first call fails, lets fall back to just use MiniDumpWithFullMemory then.
if (!WindowsDbgHelp::miniDumpWriteDump(hProcess, processId, dumpFile, dumpType, pmei, NULL, NULL) &&
!WindowsDbgHelp::miniDumpWriteDump(hProcess, processId, dumpFile, (MINIDUMP_TYPE)MiniDumpWithFullMemory, pmei, NULL, NULL)) {
jio_fprintf(stderr, "Call to MiniDumpWriteDump() failed (Error 0x%x)\n", GetLastError());
}
CloseHandle(dumpFile);
win32::exit_process_or_thread(win32::EPT_PROCESS, 1);
}
// Die immediately, no exit hook, no abort hook, no cleanup.
void os::die() {
win32::exit_process_or_thread(win32::EPT_PROCESS_DIE, -1);
}
// Directory routines copied from src/win32/native/java/io/dirent_md.c
// * dirent_md.c 1.15 00/02/02
//
// The declarations for DIR and struct dirent are in jvm_win32.h.
// Caller must have already run dirname through JVM_NativePath, which removes
// duplicate slashes and converts all instances of '/' into '\\'.
DIR * os::opendir(const char *dirname) {
assert(dirname != NULL, "just checking"); // hotspot change
DIR *dirp = (DIR *)malloc(sizeof(DIR), mtInternal);
DWORD fattr; // hotspot change
char alt_dirname[4] = { 0, 0, 0, 0 };
if (dirp == 0) {
errno = ENOMEM;
return 0;
}
// Win32 accepts "\" in its POSIX stat(), but refuses to treat it
// as a directory in FindFirstFile(). We detect this case here and
// prepend the current drive name.
//
if (dirname[1] == '\0' && dirname[0] == '\\') {
alt_dirname[0] = _getdrive() + 'A' - 1;
alt_dirname[1] = ':';
alt_dirname[2] = '\\';
alt_dirname[3] = '\0';
dirname = alt_dirname;
}
dirp->path = (char *)malloc(strlen(dirname) + 5, mtInternal);
if (dirp->path == 0) {
free(dirp);
errno = ENOMEM;
return 0;
}
strcpy(dirp->path, dirname);
fattr = GetFileAttributes(dirp->path);
if (fattr == 0xffffffff) {
free(dirp->path);
free(dirp);
errno = ENOENT;
return 0;
} else if ((fattr & FILE_ATTRIBUTE_DIRECTORY) == 0) {
free(dirp->path);
free(dirp);
errno = ENOTDIR;
return 0;
}
// Append "*.*", or possibly "\\*.*", to path
if (dirp->path[1] == ':' &&
(dirp->path[2] == '\0' ||
(dirp->path[2] == '\\' && dirp->path[3] == '\0'))) {
// No '\\' needed for cases like "Z:" or "Z:\"
strcat(dirp->path, "*.*");
} else {
strcat(dirp->path, "\\*.*");
}
dirp->handle = FindFirstFile(dirp->path, &dirp->find_data);
if (dirp->handle == INVALID_HANDLE_VALUE) {
if (GetLastError() != ERROR_FILE_NOT_FOUND) {
free(dirp->path);
free(dirp);
errno = EACCES;
return 0;
}
}
return dirp;
}
struct dirent * os::readdir(DIR *dirp) {
assert(dirp != NULL, "just checking"); // hotspot change
if (dirp->handle == INVALID_HANDLE_VALUE) {
return NULL;
}
strcpy(dirp->dirent.d_name, dirp->find_data.cFileName);
if (!FindNextFile(dirp->handle, &dirp->find_data)) {
if (GetLastError() == ERROR_INVALID_HANDLE) {
errno = EBADF;
return NULL;
}
FindClose(dirp->handle);
dirp->handle = INVALID_HANDLE_VALUE;
}
return &dirp->dirent;
}
int os::closedir(DIR *dirp) {
assert(dirp != NULL, "just checking"); // hotspot change
if (dirp->handle != INVALID_HANDLE_VALUE) {
if (!FindClose(dirp->handle)) {
errno = EBADF;
return -1;
}
dirp->handle = INVALID_HANDLE_VALUE;
}
free(dirp->path);
free(dirp);
return 0;
}
// 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() {
static char path_buf[MAX_PATH];
if (GetTempPath(MAX_PATH, path_buf) > 0) {
return path_buf;
} else {
path_buf[0] = '\0';
return path_buf;
}
}
// Needs to be in os specific directory because windows requires another
// header file <direct.h>
const char* os::get_current_directory(char *buf, size_t buflen) {
int n = static_cast<int>(buflen);
if (buflen > INT_MAX) n = INT_MAX;
return _getcwd(buf, n);
}
//-----------------------------------------------------------
// Helper functions for fatal error handler
#ifdef _WIN64
// Helper routine which returns true if address in
// within the NTDLL address space.
//
static bool _addr_in_ntdll(address addr) {
HMODULE hmod;
MODULEINFO minfo;
hmod = GetModuleHandle("NTDLL.DLL");
if (hmod == NULL) return false;
if (!GetModuleInformation(GetCurrentProcess(), hmod,
&minfo, sizeof(MODULEINFO))) {
return false;
}
if ((addr >= minfo.lpBaseOfDll) &&
(addr < (address)((uintptr_t)minfo.lpBaseOfDll + (uintptr_t)minfo.SizeOfImage))) {
return true;
} else {
return false;
}
}
#endif
struct _modinfo {
address addr;
char* full_path; // point to a char buffer
int buflen; // size of the buffer
address base_addr;
};
static int _locate_module_by_addr(const char * mod_fname, address base_addr,
address top_address, void * param) {
struct _modinfo *pmod = (struct _modinfo *)param;
if (!pmod) return -1;
if (base_addr <= pmod->addr &&
top_address > pmod->addr) {
// if a buffer is provided, copy path name to the buffer
if (pmod->full_path) {
jio_snprintf(pmod->full_path, pmod->buflen, "%s", mod_fname);
}
pmod->base_addr = base_addr;
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");
// NOTE: the reason we don't use SymGetModuleInfo() is it doesn't always
// return the full path to the DLL file, sometimes it returns path
// to the corresponding PDB file (debug info); sometimes it only
// returns partial path, which makes life painful.
struct _modinfo mi;
mi.addr = addr;
mi.full_path = buf;
mi.buflen = buflen;
if (get_loaded_modules_info(_locate_module_by_addr, (void *)&mi)) {
// buf already contains path name
if (offset) *offset = addr - mi.base_addr;
return true;
}
buf[0] = '\0';
if (offset) *offset = -1;
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");
if (Decoder::decode(addr, buf, buflen, offset, demangle)) {
return true;
}
if (offset != NULL) *offset = -1;
buf[0] = '\0';
return false;
}
// save the start and end address of jvm.dll into param[0] and param[1]
static int _locate_jvm_dll(const char* mod_fname, address base_addr,
address top_address, void * param) {
if (!param) return -1;
if (base_addr <= (address)_locate_jvm_dll &&
top_address > (address)_locate_jvm_dll) {
((address*)param)[0] = base_addr;
((address*)param)[1] = top_address;
return 1;
}
return 0;
}
address vm_lib_location[2]; // start and end address of jvm.dll
// check if addr is inside jvm.dll
bool os::address_is_in_vm(address addr) {
if (!vm_lib_location[0] || !vm_lib_location[1]) {
if (!get_loaded_modules_info(_locate_jvm_dll, (void *)vm_lib_location)) {
assert(false, "Can't find jvm module.");
return false;
}
}
return (vm_lib_location[0] <= addr) && (addr < vm_lib_location[1]);
}
// print module info; param is outputStream*
static int _print_module(const char* fname, address base_address,
address top_address, void* param) {
if (!param) return -1;
outputStream* st = (outputStream*)param;
st->print(PTR_FORMAT " - " PTR_FORMAT " \t%s\n", base_address, top_address, fname);
return 0;
}
// Loads .dll/.so and
// in case of error it checks if .dll/.so was built for the
// same architecture as Hotspot is running on
void * os::dll_load(const char *name, char *ebuf, int ebuflen) {
log_info(os)("attempting shared library load of %s", name);
void * result = LoadLibrary(name);
if (result != NULL) {
Events::log(NULL, "Loaded shared library %s", name);
// Recalculate pdb search path if a DLL was loaded successfully.
SymbolEngine::recalc_search_path();
log_info(os)("shared library load of %s was successful", name);
return result;
}
DWORD errcode = GetLastError();
// Read system error message into ebuf
// It may or may not be overwritten below (in the for loop and just above)
lasterror(ebuf, (size_t) ebuflen);
ebuf[ebuflen - 1] = '\0';
Events::log(NULL, "Loading shared library %s failed, error code %lu", name, errcode);
log_info(os)("shared library load of %s failed, error code %lu", name, errcode);
if (errcode == ERROR_MOD_NOT_FOUND) {
strncpy(ebuf, "Can't find dependent libraries", ebuflen - 1);
ebuf[ebuflen - 1] = '\0';
return NULL;
}
// Parsing dll below
// If we can read dll-info and find that dll was built
// for an architecture other than Hotspot is running in
// - then print to buffer "DLL was built for a different architecture"
// else call os::lasterror to obtain system error message
int fd = ::open(name, O_RDONLY | O_BINARY, 0);
if (fd < 0) {
return NULL;
}
uint32_t signature_offset;
uint16_t lib_arch = 0;
bool failed_to_get_lib_arch =
( // Go to position 3c in the dll
(os::seek_to_file_offset(fd, IMAGE_FILE_PTR_TO_SIGNATURE) < 0)
||
// Read location of signature
(sizeof(signature_offset) !=
(os::read(fd, (void*)&signature_offset, sizeof(signature_offset))))
||
// Go to COFF File Header in dll
// that is located after "signature" (4 bytes long)
(os::seek_to_file_offset(fd,
signature_offset + IMAGE_FILE_SIGNATURE_LENGTH) < 0)
||
// Read field that contains code of architecture
// that dll was built for
(sizeof(lib_arch) != (os::read(fd, (void*)&lib_arch, sizeof(lib_arch))))
);
::close(fd);
if (failed_to_get_lib_arch) {
// file i/o error - report os::lasterror(...) msg
return NULL;
}
typedef struct {
uint16_t arch_code;
char* arch_name;
} arch_t;
static const arch_t arch_array[] = {
{IMAGE_FILE_MACHINE_I386, (char*)"IA 32"},
{IMAGE_FILE_MACHINE_AMD64, (char*)"AMD 64"}
};
#if (defined _M_AMD64)
static const uint16_t running_arch = IMAGE_FILE_MACHINE_AMD64;
#elif (defined _M_IX86)
static const uint16_t running_arch = IMAGE_FILE_MACHINE_I386;
#else
#error Method os::dll_load requires that one of following \
is defined :_M_AMD64 or _M_IX86
#endif
// Obtain a string for printf operation
// lib_arch_str shall contain string what platform this .dll was built for
// running_arch_str shall string contain what platform Hotspot was built for
char *running_arch_str = NULL, *lib_arch_str = NULL;
for (unsigned int i = 0; i < ARRAY_SIZE(arch_array); i++) {
if (lib_arch == arch_array[i].arch_code) {
lib_arch_str = arch_array[i].arch_name;
}
if (running_arch == arch_array[i].arch_code) {
running_arch_str = arch_array[i].arch_name;
}
}
assert(running_arch_str,
"Didn't find running architecture code in arch_array");
// If the architecture is right
// but some other error took place - report os::lasterror(...) msg
if (lib_arch == running_arch) {
return NULL;
}
if (lib_arch_str != NULL) {
::_snprintf(ebuf, ebuflen - 1,
"Can't load %s-bit .dll on a %s-bit platform",
lib_arch_str, running_arch_str);
} else {
// don't know what architecture this dll was build for
::_snprintf(ebuf, ebuflen - 1,
"Can't load this .dll (machine code=0x%x) on a %s-bit platform",
lib_arch, running_arch_str);
}
return NULL;
}
void os::print_dll_info(outputStream *st) {
st->print_cr("Dynamic libraries:");
get_loaded_modules_info(_print_module, (void *)st);
}
int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
HANDLE hProcess;
# define MAX_NUM_MODULES 128
HMODULE modules[MAX_NUM_MODULES];
static char filename[MAX_PATH];
int result = 0;
int pid = os::current_process_id();
hProcess = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ,
FALSE, pid);
if (hProcess == NULL) return 0;
DWORD size_needed;
if (!EnumProcessModules(hProcess, modules, sizeof(modules), &size_needed)) {
CloseHandle(hProcess);
return 0;
}
// number of modules that are currently loaded
int num_modules = size_needed / sizeof(HMODULE);
for (int i = 0; i < MIN2(num_modules, MAX_NUM_MODULES); i++) {
// Get Full pathname:
if (!GetModuleFileNameEx(hProcess, modules[i], filename, sizeof(filename))) {
filename[0] = '\0';
}
MODULEINFO modinfo;
if (!GetModuleInformation(hProcess, modules[i], &modinfo, sizeof(modinfo))) {
modinfo.lpBaseOfDll = NULL;
modinfo.SizeOfImage = 0;
}
// Invoke callback function
result = callback(filename, (address)modinfo.lpBaseOfDll,
(address)((u8)modinfo.lpBaseOfDll + (u8)modinfo.SizeOfImage), param);
if (result) break;
}
CloseHandle(hProcess);
return result;
}
bool os::get_host_name(char* buf, size_t buflen) {
DWORD size = (DWORD)buflen;
return (GetComputerNameEx(ComputerNameDnsHostname, buf, &size) == TRUE);
}
void os::get_summary_os_info(char* buf, size_t buflen) {
stringStream sst(buf, buflen);
os::win32::print_windows_version(&sst);
// chop off newline character
char* nl = strchr(buf, '\n');
if (nl != NULL) *nl = '\0';
}
int os::vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
#if _MSC_VER >= 1900
// Starting with Visual Studio 2015, vsnprint is C99 compliant.
int result = ::vsnprintf(buf, len, fmt, args);
// If an encoding error occurred (result < 0) then it's not clear
// whether the buffer is NUL terminated, so ensure it is.
if ((result < 0) && (len > 0)) {
buf[len - 1] = '\0';
}
return result;
#else
// Before Visual Studio 2015, vsnprintf is not C99 compliant, so use
// _vsnprintf, whose behavior seems to be *mostly* consistent across
// versions. However, when len == 0, avoid _vsnprintf too, and just
// go straight to _vscprintf. The output is going to be truncated in
// that case, except in the unusual case of empty output. More
// importantly, the documentation for various versions of Visual Studio
// are inconsistent about the behavior of _vsnprintf when len == 0,
// including it possibly being an error.
int result = -1;
if (len > 0) {
result = _vsnprintf(buf, len, fmt, args);
// If output (including NUL terminator) is truncated, the buffer
// won't be NUL terminated. Add the trailing NUL specified by C99.
if ((result < 0) || ((size_t)result >= len)) {
buf[len - 1] = '\0';
}
}
if (result < 0) {
result = _vscprintf(fmt, args);
}
return result;
#endif // _MSC_VER dispatch
}
static inline time_t get_mtime(const char* filename) {
struct stat st;
int ret = os::stat(filename, &st);
assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
return st.st_mtime;
}
int os::compare_file_modified_times(const char* file1, const char* file2) {
time_t t1 = get_mtime(file1);
time_t t2 = get_mtime(file2);
return t1 - t2;
}
void os::print_os_info_brief(outputStream* st) {
os::print_os_info(st);
}
void os::win32::print_uptime_info(outputStream* st) {
unsigned long long ticks = GetTickCount64();
os::print_dhm(st, "OS uptime:", ticks/1000);
}
void os::print_os_info(outputStream* st) {
#ifdef ASSERT
char buffer[1024];
st->print("HostName: ");
if (get_host_name(buffer, sizeof(buffer))) {
st->print("%s ", buffer);
} else {
st->print("N/A ");
}
#endif
st->print("OS:");
os::win32::print_windows_version(st);
os::win32::print_uptime_info(st);
#ifdef _LP64
VM_Version::print_platform_virtualization_info(st);
#endif
}
void os::win32::print_windows_version(outputStream* st) {
OSVERSIONINFOEX osvi;
VS_FIXEDFILEINFO *file_info;
TCHAR kernel32_path[MAX_PATH];
UINT len, ret;
// Use the GetVersionEx information to see if we're on a server or
// workstation edition of Windows. Starting with Windows 8.1 we can't
// trust the OS version information returned by this API.
ZeroMemory(&osvi, sizeof(OSVERSIONINFOEX));
osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
if (!GetVersionEx((OSVERSIONINFO *)&osvi)) {
st->print_cr("Call to GetVersionEx failed");
return;
}
bool is_workstation = (osvi.wProductType == VER_NT_WORKSTATION);
// Get the full path to \Windows\System32\kernel32.dll and use that for
// determining what version of Windows we're running on.
len = MAX_PATH - (UINT)strlen("\\kernel32.dll") - 1;
ret = GetSystemDirectory(kernel32_path, len);
if (ret == 0 || ret > len) {
st->print_cr("Call to GetSystemDirectory failed");
return;
}
strncat(kernel32_path, "\\kernel32.dll", MAX_PATH - ret);
DWORD version_size = GetFileVersionInfoSize(kernel32_path, NULL);
if (version_size == 0) {
st->print_cr("Call to GetFileVersionInfoSize failed");
return;
}
LPTSTR version_info = (LPTSTR)os::malloc(version_size, mtInternal);
if (version_info == NULL) {
st->print_cr("Failed to allocate version_info");
return;
}
if (!GetFileVersionInfo(kernel32_path, NULL, version_size, version_info)) {
os::free(version_info);
st->print_cr("Call to GetFileVersionInfo failed");
return;
}
if (!VerQueryValue(version_info, TEXT("\\"), (LPVOID*)&file_info, &len)) {
os::free(version_info);
st->print_cr("Call to VerQueryValue failed");
return;
}
int major_version = HIWORD(file_info->dwProductVersionMS);
int minor_version = LOWORD(file_info->dwProductVersionMS);
int build_number = HIWORD(file_info->dwProductVersionLS);
int build_minor = LOWORD(file_info->dwProductVersionLS);
int os_vers = major_version * 1000 + minor_version;
os::free(version_info);
st->print(" Windows ");
switch (os_vers) {
case 6000:
if (is_workstation) {
st->print("Vista");
} else {
st->print("Server 2008");
}
break;
case 6001:
if (is_workstation) {
st->print("7");
} else {
st->print("Server 2008 R2");
}
break;
case 6002:
if (is_workstation) {
st->print("8");
} else {
st->print("Server 2012");
}
break;
case 6003:
if (is_workstation) {
st->print("8.1");
} else {
st->print("Server 2012 R2");
}
break;
case 10000:
if (is_workstation) {
st->print("10");
} else {
// distinguish Windows Server 2016 and 2019 by build number
// Windows server 2019 GA 10/2018 build number is 17763
if (build_number > 17762) {
st->print("Server 2019");
} else {
st->print("Server 2016");
}
}
break;
default:
// Unrecognized windows, print out its major and minor versions
st->print("%d.%d", major_version, minor_version);
break;
}
// Retrieve SYSTEM_INFO from GetNativeSystemInfo call so that we could
// find out whether we are running on 64 bit processor or not
SYSTEM_INFO si;
ZeroMemory(&si, sizeof(SYSTEM_INFO));
GetNativeSystemInfo(&si);
if (si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_AMD64) {
st->print(" , 64 bit");
}
st->print(" Build %d", build_number);
st->print(" (%d.%d.%d.%d)", major_version, minor_version, build_number, build_minor);
st->cr();
}
void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
// Nothing to do for now.
}
void os::get_summary_cpu_info(char* buf, size_t buflen) {
HKEY key;
DWORD status = RegOpenKey(HKEY_LOCAL_MACHINE,
"HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0", &key);
if (status == ERROR_SUCCESS) {
DWORD size = (DWORD)buflen;
status = RegQueryValueEx(key, "ProcessorNameString", NULL, NULL, (byte*)buf, &size);
if (status != ERROR_SUCCESS) {
strncpy(buf, "## __CPU__", buflen);
}
RegCloseKey(key);
} else {
// Put generic cpu info to return
strncpy(buf, "## __CPU__", buflen);
}
}
void os::print_memory_info(outputStream* st) {
st->print("Memory:");
st->print(" %dk page", os::vm_page_size()>>10);
// Use GlobalMemoryStatusEx() because GlobalMemoryStatus() may return incorrect
// value if total memory is larger than 4GB
MEMORYSTATUSEX ms;
ms.dwLength = sizeof(ms);
int r1 = GlobalMemoryStatusEx(&ms);
if (r1 != 0) {
st->print(", system-wide physical " INT64_FORMAT "M ",
(int64_t) ms.ullTotalPhys >> 20);
st->print("(" INT64_FORMAT "M free)\n", (int64_t) ms.ullAvailPhys >> 20);
st->print("TotalPageFile size " INT64_FORMAT "M ",
(int64_t) ms.ullTotalPageFile >> 20);
st->print("(AvailPageFile size " INT64_FORMAT "M)",
(int64_t) ms.ullAvailPageFile >> 20);
// on 32bit Total/AvailVirtual are interesting (show us how close we get to 2-4 GB per process borders)
#if defined(_M_IX86)
st->print(", user-mode portion of virtual address-space " INT64_FORMAT "M ",
(int64_t) ms.ullTotalVirtual >> 20);
st->print("(" INT64_FORMAT "M free)", (int64_t) ms.ullAvailVirtual >> 20);
#endif
} else {
st->print(", GlobalMemoryStatusEx did not succeed so we miss some memory values.");
}
// extended memory statistics for a process
PROCESS_MEMORY_COUNTERS_EX pmex;
ZeroMemory(&pmex, sizeof(PROCESS_MEMORY_COUNTERS_EX));
pmex.cb = sizeof(pmex);
int r2 = GetProcessMemoryInfo(GetCurrentProcess(), (PROCESS_MEMORY_COUNTERS*) &pmex, sizeof(pmex));
if (r2 != 0) {
st->print("\ncurrent process WorkingSet (physical memory assigned to process): " INT64_FORMAT "M, ",
(int64_t) pmex.WorkingSetSize >> 20);
st->print("peak: " INT64_FORMAT "M\n", (int64_t) pmex.PeakWorkingSetSize >> 20);
st->print("current process commit charge (\"private bytes\"): " INT64_FORMAT "M, ",
(int64_t) pmex.PrivateUsage >> 20);
st->print("peak: " INT64_FORMAT "M", (int64_t) pmex.PeakPagefileUsage >> 20);
} else {
st->print("\nGetProcessMemoryInfo did not succeed so we miss some memory values.");
}
st->cr();
}
bool os::signal_sent_by_kill(const void* siginfo) {
// TODO: Is this possible?
return false;
}
void os::print_siginfo(outputStream *st, const void* siginfo) {
const EXCEPTION_RECORD* const er = (EXCEPTION_RECORD*)siginfo;
st->print("siginfo:");
char tmp[64];
if (os::exception_name(er->ExceptionCode, tmp, sizeof(tmp)) == NULL) {
strcpy(tmp, "EXCEPTION_??");
}
st->print(" %s (0x%x)", tmp, er->ExceptionCode);
if ((er->ExceptionCode == EXCEPTION_ACCESS_VIOLATION ||
er->ExceptionCode == EXCEPTION_IN_PAGE_ERROR) &&
er->NumberParameters >= 2) {
switch (er->ExceptionInformation[0]) {
case 0: st->print(", reading address"); break;
case 1: st->print(", writing address"); break;
case 8: st->print(", data execution prevention violation at address"); break;
default: st->print(", ExceptionInformation=" INTPTR_FORMAT,
er->ExceptionInformation[0]);
}
st->print(" " INTPTR_FORMAT, er->ExceptionInformation[1]);
} else {
int num = er->NumberParameters;
if (num > 0) {
st->print(", ExceptionInformation=");
for (int i = 0; i < num; i++) {
st->print(INTPTR_FORMAT " ", er->ExceptionInformation[i]);
}
}
}
st->cr();
}
bool os::signal_thread(Thread* thread, int sig, const char* reason) {
// TODO: Can we kill thread?
return false;
}
void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
// do nothing
}
static char saved_jvm_path[MAX_PATH] = {0};
// Find the full path to the current module, jvm.dll
void os::jvm_path(char *buf, jint buflen) {
// Error checking.
if (buflen < MAX_PATH) {
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;
}
buf[0] = '\0';
if (Arguments::sun_java_launcher_is_altjvm()) {
// Support for the java launcher's '-XXaltjvm=<path>' option. Check
// for a JAVA_HOME environment variable and fix up the path so it
// looks like jvm.dll is installed there (append a fake suffix
// hotspot/jvm.dll).
char* java_home_var = ::getenv("JAVA_HOME");
if (java_home_var != NULL && java_home_var[0] != 0 &&
strlen(java_home_var) < (size_t)buflen) {
strncpy(buf, java_home_var, buflen);
// determine if this is a legacy image or modules image
// modules image doesn't have "jre" subdirectory
size_t len = strlen(buf);
char* jrebin_p = buf + len;
jio_snprintf(jrebin_p, buflen-len, "\\jre\\bin\\");
if (0 != _access(buf, 0)) {
jio_snprintf(jrebin_p, buflen-len, "\\bin\\");
}
len = strlen(buf);
jio_snprintf(buf + len, buflen-len, "hotspot\\jvm.dll");
}
}
if (buf[0] == '\0') {
GetModuleFileName(vm_lib_handle, buf, buflen);
}
strncpy(saved_jvm_path, buf, MAX_PATH);
saved_jvm_path[MAX_PATH - 1] = '\0';
}
void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
#ifndef _WIN64
st->print("_");
#endif
}
void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
#ifndef _WIN64
st->print("@%d", args_size * sizeof(int));
#endif
}
// This method is a copy of JDK's sysGetLastErrorString
// from src/windows/hpi/src/system_md.c
size_t os::lasterror(char* buf, size_t len) {
DWORD errval;
if ((errval = GetLastError()) != 0) {
// DOS error
size_t n = (size_t)FormatMessage(
FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,
NULL,
errval,
0,
buf,
(DWORD)len,
NULL);
if (n > 3) {
// Drop final '.', CR, LF
if (buf[n - 1] == '\n') n--;
if (buf[n - 1] == '\r') n--;
if (buf[n - 1] == '.') n--;
buf[n] = '\0';
}
return n;
}
if (errno != 0) {
// C runtime error that has no corresponding DOS error code
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;
}
return 0;
}
int os::get_last_error() {
DWORD error = GetLastError();
if (error == 0) {
error = errno;
}
return (int)error;
}
// sun.misc.Signal
// NOTE that this is a workaround for an apparent kernel bug where if
// a signal handler for SIGBREAK is installed then that signal handler
// takes priority over the console control handler for CTRL_CLOSE_EVENT.
// See bug 4416763.
static void (*sigbreakHandler)(int) = NULL;
static void UserHandler(int sig, void *siginfo, void *context) {
os::signal_notify(sig);
// We need to reinstate the signal handler each time...
os::signal(sig, (void*)UserHandler);
}
void* os::user_handler() {
return (void*) UserHandler;
}
void* os::signal(int signal_number, void* handler) {
if ((signal_number == SIGBREAK) && (!ReduceSignalUsage)) {
void (*oldHandler)(int) = sigbreakHandler;
sigbreakHandler = (void (*)(int)) handler;
return (void*) oldHandler;
} else {
return (void*)::signal(signal_number, (void (*)(int))handler);
}
}
void os::signal_raise(int signal_number) {
raise(signal_number);
}
// The Win32 C runtime library maps all console control events other than ^C
// into SIGBREAK, which makes it impossible to distinguish ^BREAK from close,
// logoff, and shutdown events. We therefore install our own console handler
// that raises SIGTERM for the latter cases.
//
static BOOL WINAPI consoleHandler(DWORD event) {
switch (event) {
case CTRL_C_EVENT:
if (VMError::is_error_reported()) {
// Ctrl-C is pressed during error reporting, likely because the error
// handler fails to abort. Let VM die immediately.
os::die();
}
os::signal_raise(SIGINT);
return TRUE;
break;
case CTRL_BREAK_EVENT:
if (sigbreakHandler != NULL) {
(*sigbreakHandler)(SIGBREAK);
}
return TRUE;
break;
case CTRL_LOGOFF_EVENT: {
// Don't terminate JVM if it is running in a non-interactive session,
// such as a service process.
USEROBJECTFLAGS flags;
HANDLE handle = GetProcessWindowStation();
if (handle != NULL &&
GetUserObjectInformation(handle, UOI_FLAGS, &flags,
sizeof(USEROBJECTFLAGS), NULL)) {
// If it is a non-interactive session, let next handler to deal
// with it.
if ((flags.dwFlags & WSF_VISIBLE) == 0) {
return FALSE;
}
}
}
case CTRL_CLOSE_EVENT:
case CTRL_SHUTDOWN_EVENT:
os::signal_raise(SIGTERM);
return TRUE;
break;
default:
break;
}
return FALSE;
}
// The following code is moved from os.cpp for making this
// code platform specific, which it is by its very nature.
// Return maximum OS signal used + 1 for internal use only
// Used as exit signal for signal_thread
int os::sigexitnum_pd() {
return NSIG;
}
// a counter for each possible signal value, including signal_thread exit signal
static volatile jint pending_signals[NSIG+1] = { 0 };
static Semaphore* sig_sem = NULL;
static void jdk_misc_signal_init() {
// Initialize signal structures
memset((void*)pending_signals, 0, sizeof(pending_signals));
// Initialize signal semaphore
sig_sem = new Semaphore();
// Programs embedding the VM do not want it to attempt to receive
// events like CTRL_LOGOFF_EVENT, which are used to implement the
// shutdown hooks mechanism introduced in 1.3. For example, when
// the VM is run as part of a Windows NT service (i.e., a servlet
// engine in a web server), the correct behavior is for any console
// control handler to return FALSE, not TRUE, because the OS's
// "final" handler for such events allows the process to continue if
// it is a service (while terminating it if it is not a service).
// To make this behavior uniform and the mechanism simpler, we
// completely disable the VM's usage of these console events if -Xrs
// (=ReduceSignalUsage) is specified. This means, for example, that
// the CTRL-BREAK thread dump mechanism is also disabled in this
// case. See bugs 4323062, 4345157, and related bugs.
// Add a CTRL-C handler
SetConsoleCtrlHandler(consoleHandler, TRUE);
}
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() {
while (true) {
for (int i = 0; i < NSIG + 1; i++) {
jint n = pending_signals[i];
if (n > 0 && n == Atomic::cmpxchg(&pending_signals[i], n, n - 1)) {
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();
}
// Implicit OS exception handling
LONG Handle_Exception(struct _EXCEPTION_POINTERS* exceptionInfo,
address handler) {
JavaThread* thread = (JavaThread*) Thread::current_or_null();
// Save pc in thread
#ifdef _M_AMD64
// Do not blow up if no thread info available.
if (thread) {
thread->set_saved_exception_pc((address)(DWORD_PTR)exceptionInfo->ContextRecord->Rip);
}
// Set pc to handler
exceptionInfo->ContextRecord->Rip = (DWORD64)handler;
#else
// Do not blow up if no thread info available.
if (thread) {
thread->set_saved_exception_pc((address)(DWORD_PTR)exceptionInfo->ContextRecord->Eip);
}
// Set pc to handler
exceptionInfo->ContextRecord->Eip = (DWORD)(DWORD_PTR)handler;
#endif
// Continue the execution
return EXCEPTION_CONTINUE_EXECUTION;
}
// Used for PostMortemDump
extern "C" void safepoints();
extern "C" void find(int x);
extern "C" void events();
// According to Windows API documentation, an illegal instruction sequence should generate
// the 0xC000001C exception code. However, real world experience shows that occasionnaly
// the execution of an illegal instruction can generate the exception code 0xC000001E. This
// seems to be an undocumented feature of Win NT 4.0 (and probably other Windows systems).
#define EXCEPTION_ILLEGAL_INSTRUCTION_2 0xC000001E
// From "Execution Protection in the Windows Operating System" draft 0.35
// Once a system header becomes available, the "real" define should be
// included or copied here.
#define EXCEPTION_INFO_EXEC_VIOLATION 0x08
// Windows Vista/2008 heap corruption check
#define EXCEPTION_HEAP_CORRUPTION 0xC0000374
// All Visual C++ exceptions thrown from code generated by the Microsoft Visual
// C++ compiler contain this error code. Because this is a compiler-generated
// error, the code is not listed in the Win32 API header files.
// The code is actually a cryptic mnemonic device, with the initial "E"
// standing for "exception" and the final 3 bytes (0x6D7363) representing the
// ASCII values of "msc".
#define EXCEPTION_UNCAUGHT_CXX_EXCEPTION 0xE06D7363
#define def_excpt(val) { #val, (val) }
static const struct { const char* name; uint number; } exceptlabels[] = {
def_excpt(EXCEPTION_ACCESS_VIOLATION),
def_excpt(EXCEPTION_DATATYPE_MISALIGNMENT),
def_excpt(EXCEPTION_BREAKPOINT),
def_excpt(EXCEPTION_SINGLE_STEP),
def_excpt(EXCEPTION_ARRAY_BOUNDS_EXCEEDED),
def_excpt(EXCEPTION_FLT_DENORMAL_OPERAND),
def_excpt(EXCEPTION_FLT_DIVIDE_BY_ZERO),
def_excpt(EXCEPTION_FLT_INEXACT_RESULT),
def_excpt(EXCEPTION_FLT_INVALID_OPERATION),
def_excpt(EXCEPTION_FLT_OVERFLOW),
def_excpt(EXCEPTION_FLT_STACK_CHECK),
def_excpt(EXCEPTION_FLT_UNDERFLOW),
def_excpt(EXCEPTION_INT_DIVIDE_BY_ZERO),
def_excpt(EXCEPTION_INT_OVERFLOW),
def_excpt(EXCEPTION_PRIV_INSTRUCTION),
def_excpt(EXCEPTION_IN_PAGE_ERROR),
def_excpt(EXCEPTION_ILLEGAL_INSTRUCTION),
def_excpt(EXCEPTION_ILLEGAL_INSTRUCTION_2),
def_excpt(EXCEPTION_NONCONTINUABLE_EXCEPTION),
def_excpt(EXCEPTION_STACK_OVERFLOW),
def_excpt(EXCEPTION_INVALID_DISPOSITION),
def_excpt(EXCEPTION_GUARD_PAGE),
def_excpt(EXCEPTION_INVALID_HANDLE),
def_excpt(EXCEPTION_UNCAUGHT_CXX_EXCEPTION),
def_excpt(EXCEPTION_HEAP_CORRUPTION)
};
#undef def_excpt
const char* os::exception_name(int exception_code, char *buf, size_t size) {
uint code = static_cast<uint>(exception_code);
for (uint i = 0; i < ARRAY_SIZE(exceptlabels); ++i) {
if (exceptlabels[i].number == code) {
jio_snprintf(buf, size, "%s", exceptlabels[i].name);
return buf;
}
}
return NULL;
}
//-----------------------------------------------------------------------------
LONG Handle_IDiv_Exception(struct _EXCEPTION_POINTERS* exceptionInfo) {
// handle exception caused by idiv; should only happen for -MinInt/-1
// (division by zero is handled explicitly)
#ifdef _M_AMD64
PCONTEXT ctx = exceptionInfo->ContextRecord;
address pc = (address)ctx->Rip;
assert(pc[0] >= Assembler::REX && pc[0] <= Assembler::REX_WRXB && pc[1] == 0xF7 || pc[0] == 0xF7, "not an idiv opcode");
assert(pc[0] >= Assembler::REX && pc[0] <= Assembler::REX_WRXB && (pc[2] & ~0x7) == 0xF8 || (pc[1] & ~0x7) == 0xF8, "cannot handle non-register operands");
if (pc[0] == 0xF7) {
// set correct result values and continue after idiv instruction
ctx->Rip = (DWORD64)pc + 2; // idiv reg, reg is 2 bytes
} else {
ctx->Rip = (DWORD64)pc + 3; // REX idiv reg, reg is 3 bytes
}
// Do not set ctx->Rax as it already contains the correct value (either 32 or 64 bit, depending on the operation)
// this is the case because the exception only happens for -MinValue/-1 and -MinValue is always in rax because of the
// idiv opcode (0xF7).
ctx->Rdx = (DWORD)0; // remainder
// Continue the execution
#else
PCONTEXT ctx = exceptionInfo->ContextRecord;
address pc = (address)ctx->Eip;
assert(pc[0] == 0xF7, "not an idiv opcode");
assert((pc[1] & ~0x7) == 0xF8, "cannot handle non-register operands");
assert(ctx->Eax == min_jint, "unexpected idiv exception");
// set correct result values and continue after idiv instruction
ctx->Eip = (DWORD)pc + 2; // idiv reg, reg is 2 bytes
ctx->Eax = (DWORD)min_jint; // result
ctx->Edx = (DWORD)0; // remainder
// Continue the execution
#endif
return EXCEPTION_CONTINUE_EXECUTION;
}
//-----------------------------------------------------------------------------
LONG WINAPI Handle_FLT_Exception(struct _EXCEPTION_POINTERS* exceptionInfo) {
PCONTEXT ctx = exceptionInfo->ContextRecord;
#ifndef _WIN64
// handle exception caused by native method modifying control word
DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode;
switch (exception_code) {
case EXCEPTION_FLT_DENORMAL_OPERAND:
case EXCEPTION_FLT_DIVIDE_BY_ZERO:
case EXCEPTION_FLT_INEXACT_RESULT:
case EXCEPTION_FLT_INVALID_OPERATION:
case EXCEPTION_FLT_OVERFLOW:
case EXCEPTION_FLT_STACK_CHECK:
case EXCEPTION_FLT_UNDERFLOW:
jint fp_control_word = (* (jint*) StubRoutines::addr_fpu_cntrl_wrd_std());
if (fp_control_word != ctx->FloatSave.ControlWord) {
// Restore FPCW and mask out FLT exceptions
ctx->FloatSave.ControlWord = fp_control_word | 0xffffffc0;
// Mask out pending FLT exceptions
ctx->FloatSave.StatusWord &= 0xffffff00;
return EXCEPTION_CONTINUE_EXECUTION;
}
}
if (prev_uef_handler != NULL) {
// We didn't handle this exception so pass it to the previous
// UnhandledExceptionFilter.
return (prev_uef_handler)(exceptionInfo);
}
#else // !_WIN64
// On Windows, the mxcsr control bits are non-volatile across calls
// See also CR 6192333
//
jint MxCsr = INITIAL_MXCSR;
// we can't use StubRoutines::addr_mxcsr_std()
// because in Win64 mxcsr is not saved there
if (MxCsr != ctx->MxCsr) {
ctx->MxCsr = MxCsr;
return EXCEPTION_CONTINUE_EXECUTION;
}
#endif // !_WIN64
return EXCEPTION_CONTINUE_SEARCH;
}
static inline void report_error(Thread* t, DWORD exception_code,
address addr, void* siginfo, void* context) {
VMError::report_and_die(t, exception_code, addr, siginfo, context);
// If UseOsErrorReporting, this will return here and save the error file
// somewhere where we can find it in the minidump.
}
bool os::win32::get_frame_at_stack_banging_point(JavaThread* thread,
struct _EXCEPTION_POINTERS* exceptionInfo, address pc, frame* fr) {
PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
address addr = (address) exceptionRecord->ExceptionInformation[1];
if (Interpreter::contains(pc)) {
*fr = os::fetch_frame_from_context((void*)exceptionInfo->ContextRecord);
if (!fr->is_first_java_frame()) {
// get_frame_at_stack_banging_point() is only called when we
// have well defined stacks so java_sender() calls do not need
// to assert safe_for_sender() first.
*fr = fr->java_sender();
}
} else {
// more complex code with compiled code
assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
CodeBlob* cb = CodeCache::find_blob(pc);
if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
// Not sure where the pc points to, fallback to default
// stack overflow handling
return false;
} else {
*fr = os::fetch_frame_from_context((void*)exceptionInfo->ContextRecord);
// in compiled code, the stack banging is performed just after the return pc
// has been pushed on the stack
*fr = frame(fr->sp() + 1, fr->fp(), (address)*(fr->sp()));
if (!fr->is_java_frame()) {
// See java_sender() comment above.
*fr = fr->java_sender();
}
}
}
assert(fr->is_java_frame(), "Safety check");
return true;
}
#if INCLUDE_AOT
LONG WINAPI topLevelVectoredExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
address addr = (address) exceptionRecord->ExceptionInformation[1];
address pc = (address) exceptionInfo->ContextRecord->Rip;
// Handle the case where we get an implicit exception in AOT generated
// code. AOT DLL's loaded are not registered for structured exceptions.
// If the exception occurred in the codeCache or AOT code, pass control
// to our normal exception handler.
CodeBlob* cb = CodeCache::find_blob(pc);
if (cb != NULL) {
return topLevelExceptionFilter(exceptionInfo);
}
return EXCEPTION_CONTINUE_SEARCH;
}
#endif
//-----------------------------------------------------------------------------
LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
if (InterceptOSException) return EXCEPTION_CONTINUE_SEARCH;
DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode;
#ifdef _M_AMD64
address pc = (address) exceptionInfo->ContextRecord->Rip;
#else
address pc = (address) exceptionInfo->ContextRecord->Eip;
#endif
Thread* t = Thread::current_or_null_safe();
// Handle SafeFetch32 and SafeFetchN exceptions.
if (StubRoutines::is_safefetch_fault(pc)) {
return Handle_Exception(exceptionInfo, StubRoutines::continuation_for_safefetch_fault(pc));
}
#ifndef _WIN64
// Execution protection violation - win32 running on AMD64 only
// Handled first to avoid misdiagnosis as a "normal" access violation;
// This is safe to do because we have a new/unique ExceptionInformation
// code for this condition.
if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
int exception_subcode = (int) exceptionRecord->ExceptionInformation[0];
address addr = (address) exceptionRecord->ExceptionInformation[1];
if (exception_subcode == EXCEPTION_INFO_EXEC_VIOLATION) {
int page_size = os::vm_page_size();
// Make sure the pc and the faulting address are sane.
//
// If an instruction spans a page boundary, and the page containing
// the beginning of the instruction is executable but the following
// page is not, the pc and the faulting address might be slightly
// different - we still want to unguard the 2nd page in this case.
//
// 15 bytes seems to be a (very) safe value for max instruction size.
bool pc_is_near_addr =
(pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
bool instr_spans_page_boundary =
(align_down((intptr_t) pc ^ (intptr_t) addr,
(intptr_t) page_size) > 0);
if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
static volatile address last_addr =
(address) os::non_memory_address_word();
// In conservative mode, don't unguard unless the address is in the VM
if (UnguardOnExecutionViolation > 0 && addr != last_addr &&
(UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
// Set memory to RWX and retry
address page_start = align_down(addr, page_size);
bool res = os::protect_memory((char*) page_start, page_size,
os::MEM_PROT_RWX);
log_debug(os)("Execution protection violation "
"at " INTPTR_FORMAT
", unguarding " INTPTR_FORMAT ": %s", p2i(addr),
p2i(page_start), (res ? "success" : os::strerror(errno)));
// Set last_addr so if we fault again at the same address, we don't
// end up in an endless loop.
//
// There are two potential complications here. Two threads trapping
// at the same address at the same time could cause one of the
// threads to think it already unguarded, and abort the VM. Likely
// very rare.
//
// The other race involves two threads alternately trapping at
// different addresses and failing to unguard the page, resulting in
// an endless loop. This condition is probably even more unlikely
// than the first.
//
// Although both cases could be avoided by using locks or thread
// local last_addr, these solutions are unnecessary complication:
// this handler is a best-effort safety net, not a complete solution.
// It is disabled by default and should only be used as a workaround
// in case we missed any no-execute-unsafe VM code.
last_addr = addr;
return EXCEPTION_CONTINUE_EXECUTION;
}
}
// Last unguard failed or not unguarding
tty->print_raw_cr("Execution protection violation");
report_error(t, exception_code, addr, exceptionInfo->ExceptionRecord,
exceptionInfo->ContextRecord);
return EXCEPTION_CONTINUE_SEARCH;
}
}
#endif // _WIN64
if ((exception_code == EXCEPTION_ACCESS_VIOLATION) &&
VM_Version::is_cpuinfo_segv_addr(pc)) {
// Verify that OS save/restore AVX registers.
return Handle_Exception(exceptionInfo, VM_Version::cpuinfo_cont_addr());
}
if (t != NULL && t->is_Java_thread()) {
JavaThread* thread = (JavaThread*) t;
bool in_java = thread->thread_state() == _thread_in_Java;
// Handle potential stack overflows up front.
if (exception_code == EXCEPTION_STACK_OVERFLOW) {
if (thread->stack_guards_enabled()) {
if (in_java) {
frame fr;
PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
address addr = (address) exceptionRecord->ExceptionInformation[1];
if (os::win32::get_frame_at_stack_banging_point(thread, exceptionInfo, pc, &fr)) {
assert(fr.is_java_frame(), "Must be a Java frame");
SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
}
}
// Yellow zone violation. The o/s has unprotected the first yellow
// zone page for us. Note: must call disable_stack_yellow_zone to
// update the enabled status, even if the zone contains only one page.
assert(thread->thread_state() != _thread_in_vm, "Undersized StackShadowPages");
thread->disable_stack_yellow_reserved_zone();
// If not in java code, return and hope for the best.
return in_java
? Handle_Exception(exceptionInfo, SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW))
: EXCEPTION_CONTINUE_EXECUTION;
} else {
// Fatal red zone violation.
thread->disable_stack_red_zone();
tty->print_raw_cr("An unrecoverable stack overflow has occurred.");
report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
exceptionInfo->ContextRecord);
return EXCEPTION_CONTINUE_SEARCH;
}
} else if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
// Either stack overflow or null pointer exception.
if (in_java) {
PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
address addr = (address) exceptionRecord->ExceptionInformation[1];
address stack_end = thread->stack_end();
if (addr < stack_end && addr >= stack_end - os::vm_page_size()) {
// Stack overflow.
assert(!os::uses_stack_guard_pages(),
"should be caught by red zone code above.");
return Handle_Exception(exceptionInfo,
SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW));
}
// Check for safepoint polling and implicit null
// We only expect null pointers in the stubs (vtable)
// the rest are checked explicitly now.
CodeBlob* cb = CodeCache::find_blob(pc);
if (cb != NULL) {
if (os::is_poll_address(addr)) {
address stub = SharedRuntime::get_poll_stub(pc);
return Handle_Exception(exceptionInfo, stub);
}
}
{
#ifdef _WIN64
// If it's a legal stack address map the entire region in
//
PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
address addr = (address) exceptionRecord->ExceptionInformation[1];
if (addr > thread->stack_reserved_zone_base() && addr < thread->stack_base()) {
addr = (address)((uintptr_t)addr &
(~((uintptr_t)os::vm_page_size() - (uintptr_t)1)));
os::commit_memory((char *)addr, thread->stack_base() - addr,
!ExecMem);
return EXCEPTION_CONTINUE_EXECUTION;
} else
#endif
{
// Null pointer exception.
if (MacroAssembler::uses_implicit_null_check((void*)addr)) {
address stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
if (stub != NULL) return Handle_Exception(exceptionInfo, stub);
}
report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
exceptionInfo->ContextRecord);
return EXCEPTION_CONTINUE_SEARCH;
}
}
}
#ifdef _WIN64
// Special care for fast JNI field accessors.
// jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks
// in and the heap gets shrunk before the field access.
if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
address addr = JNI_FastGetField::find_slowcase_pc(pc);
if (addr != (address)-1) {
return Handle_Exception(exceptionInfo, addr);
}
}
#endif
// Stack overflow or null pointer exception in native code.
report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
exceptionInfo->ContextRecord);
return EXCEPTION_CONTINUE_SEARCH;
} // /EXCEPTION_ACCESS_VIOLATION
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
if (exception_code == EXCEPTION_IN_PAGE_ERROR) {
CompiledMethod* nm = NULL;
JavaThread* thread = (JavaThread*)t;
if (in_java) {
CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
}
bool is_unsafe_arraycopy = (thread->thread_state() == _thread_in_native || in_java) && UnsafeCopyMemory::contains_pc(pc);
if (((thread->thread_state() == _thread_in_vm ||
thread->thread_state() == _thread_in_native ||
is_unsafe_arraycopy) &&
thread->doing_unsafe_access()) ||
(nm != NULL && nm->has_unsafe_access())) {
address next_pc = Assembler::locate_next_instruction(pc);
if (is_unsafe_arraycopy) {
next_pc = UnsafeCopyMemory::page_error_continue_pc(pc);
}
return Handle_Exception(exceptionInfo, SharedRuntime::handle_unsafe_access(thread, next_pc));
}
}
if (in_java) {
switch (exception_code) {
case EXCEPTION_INT_DIVIDE_BY_ZERO:
return Handle_Exception(exceptionInfo, SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO));
case EXCEPTION_INT_OVERFLOW:
return Handle_IDiv_Exception(exceptionInfo);
} // switch
}
if (((thread->thread_state() == _thread_in_Java) ||
(thread->thread_state() == _thread_in_native)) &&
exception_code != EXCEPTION_UNCAUGHT_CXX_EXCEPTION) {
LONG result=Handle_FLT_Exception(exceptionInfo);
if (result==EXCEPTION_CONTINUE_EXECUTION) return result;
}
}
if (exception_code != EXCEPTION_BREAKPOINT) {
report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
exceptionInfo->ContextRecord);
}
return EXCEPTION_CONTINUE_SEARCH;
}
#ifndef _WIN64
// Special care for fast JNI accessors.
// jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in and
// the heap gets shrunk before the field access.
// Need to install our own structured exception handler since native code may
// install its own.
LONG WINAPI fastJNIAccessorExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode;
if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
address pc = (address) exceptionInfo->ContextRecord->Eip;
address addr = JNI_FastGetField::find_slowcase_pc(pc);
if (addr != (address)-1) {
return Handle_Exception(exceptionInfo, addr);
}
}
return EXCEPTION_CONTINUE_SEARCH;
}
#define DEFINE_FAST_GETFIELD(Return, Fieldname, Result) \
Return JNICALL jni_fast_Get##Result##Field_wrapper(JNIEnv *env, \
jobject obj, \
jfieldID fieldID) { \
__try { \
return (*JNI_FastGetField::jni_fast_Get##Result##Field_fp)(env, \
obj, \
fieldID); \
} __except(fastJNIAccessorExceptionFilter((_EXCEPTION_POINTERS*) \
_exception_info())) { \
} \
return 0; \
}
DEFINE_FAST_GETFIELD(jboolean, bool, Boolean)
DEFINE_FAST_GETFIELD(jbyte, byte, Byte)
DEFINE_FAST_GETFIELD(jchar, char, Char)
DEFINE_FAST_GETFIELD(jshort, short, Short)
DEFINE_FAST_GETFIELD(jint, int, Int)
DEFINE_FAST_GETFIELD(jlong, long, Long)
DEFINE_FAST_GETFIELD(jfloat, float, Float)
DEFINE_FAST_GETFIELD(jdouble, double, Double)
address os::win32::fast_jni_accessor_wrapper(BasicType type) {
switch (type) {
case T_BOOLEAN: return (address)jni_fast_GetBooleanField_wrapper;
case T_BYTE: return (address)jni_fast_GetByteField_wrapper;
case T_CHAR: return (address)jni_fast_GetCharField_wrapper;
case T_SHORT: return (address)jni_fast_GetShortField_wrapper;
case T_INT: return (address)jni_fast_GetIntField_wrapper;
case T_LONG: return (address)jni_fast_GetLongField_wrapper;
case T_FLOAT: return (address)jni_fast_GetFloatField_wrapper;
case T_DOUBLE: return (address)jni_fast_GetDoubleField_wrapper;
default: ShouldNotReachHere();
}
return (address)-1;
}
#endif
// Virtual Memory
int os::vm_page_size() { return os::win32::vm_page_size(); }
int os::vm_allocation_granularity() {
return os::win32::vm_allocation_granularity();
}
// Windows large page support is available on Windows 2003. In order to use
// large page memory, the administrator must first assign additional privilege
// to the user:
// + select Control Panel -> Administrative Tools -> Local Security Policy
// + select Local Policies -> User Rights Assignment
// + double click "Lock pages in memory", add users and/or groups
// + reboot
// Note the above steps are needed for administrator as well, as administrators
// by default do not have the privilege to lock pages in memory.
//
// Note about Windows 2003: although the API supports committing large page
// memory on a page-by-page basis and VirtualAlloc() returns success under this
// scenario, I found through experiment it only uses large page if the entire
// memory region is reserved and committed in a single VirtualAlloc() call.
// This makes Windows large page support more or less like Solaris ISM, in
// that the entire heap must be committed upfront. This probably will change
// in the future, if so the code below needs to be revisited.
#ifndef MEM_LARGE_PAGES
#define MEM_LARGE_PAGES 0x20000000
#endif
static HANDLE _hProcess;
static HANDLE _hToken;
// Container for NUMA node list info
class NUMANodeListHolder {
private:
int *_numa_used_node_list; // allocated below
int _numa_used_node_count;
void free_node_list() {
FREE_C_HEAP_ARRAY(int, _numa_used_node_list);
}
public:
NUMANodeListHolder() {
_numa_used_node_count = 0;
_numa_used_node_list = NULL;
// do rest of initialization in build routine (after function pointers are set up)
}
~NUMANodeListHolder() {
free_node_list();
}
bool build() {
DWORD_PTR proc_aff_mask;
DWORD_PTR sys_aff_mask;
if (!GetProcessAffinityMask(GetCurrentProcess(), &proc_aff_mask, &sys_aff_mask)) return false;
ULONG highest_node_number;
if (!GetNumaHighestNodeNumber(&highest_node_number)) return false;
free_node_list();
_numa_used_node_list = NEW_C_HEAP_ARRAY(int, highest_node_number + 1, mtInternal);
for (unsigned int i = 0; i <= highest_node_number; i++) {
ULONGLONG proc_mask_numa_node;
if (!GetNumaNodeProcessorMask(i, &proc_mask_numa_node)) return false;
if ((proc_aff_mask & proc_mask_numa_node)!=0) {
_numa_used_node_list[_numa_used_node_count++] = i;
}
}
return (_numa_used_node_count > 1);
}
int get_count() { return _numa_used_node_count; }
int get_node_list_entry(int n) {
// for indexes out of range, returns -1
return (n < _numa_used_node_count ? _numa_used_node_list[n] : -1);
}
} numa_node_list_holder;
static size_t _large_page_size = 0;
static bool request_lock_memory_privilege() {
_hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE,
os::current_process_id());
LUID luid;
if (_hProcess != NULL &&
OpenProcessToken(_hProcess, TOKEN_ADJUST_PRIVILEGES, &_hToken) &&
LookupPrivilegeValue(NULL, "SeLockMemoryPrivilege", &luid)) {
TOKEN_PRIVILEGES tp;
tp.PrivilegeCount = 1;
tp.Privileges[0].Luid = luid;
tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
// AdjustTokenPrivileges() may return TRUE even when it couldn't change the
// privilege. Check GetLastError() too. See MSDN document.
if (AdjustTokenPrivileges(_hToken, false, &tp, sizeof(tp), NULL, NULL) &&
(GetLastError() == ERROR_SUCCESS)) {
return true;
}
}
return false;
}
static void cleanup_after_large_page_init() {
if (_hProcess) CloseHandle(_hProcess);
_hProcess = NULL;
if (_hToken) CloseHandle(_hToken);
_hToken = NULL;
}
static bool numa_interleaving_init() {
bool success = false;
bool use_numa_interleaving_specified = !FLAG_IS_DEFAULT(UseNUMAInterleaving);
// print a warning if UseNUMAInterleaving flag is specified on command line
bool warn_on_failure = use_numa_interleaving_specified;
#define WARN(msg) if (warn_on_failure) { warning(msg); }
// NUMAInterleaveGranularity cannot be less than vm_allocation_granularity (or _large_page_size if using large pages)
size_t min_interleave_granularity = UseLargePages ? _large_page_size : os::vm_allocation_granularity();
NUMAInterleaveGranularity = align_up(NUMAInterleaveGranularity, min_interleave_granularity);
if (numa_node_list_holder.build()) {
if (log_is_enabled(Debug, os, cpu)) {
Log(os, cpu) log;
log.debug("NUMA UsedNodeCount=%d, namely ", numa_node_list_holder.get_count());
for (int i = 0; i < numa_node_list_holder.get_count(); i++) {
log.debug(" %d ", numa_node_list_holder.get_node_list_entry(i));
}
}
success = true;
} else {
WARN("Process does not cover multiple NUMA nodes.");
}
if (!success) {
if (use_numa_interleaving_specified) WARN("...Ignoring UseNUMAInterleaving flag.");
}
return success;
#undef WARN
}
// this routine is used whenever we need to reserve a contiguous VA range
// but we need to make separate VirtualAlloc calls for each piece of the range
// Reasons for doing this:
// * UseLargePagesIndividualAllocation was set (normally only needed on WS2003 but possible to be set otherwise)
// * UseNUMAInterleaving requires a separate node for each piece
static char* allocate_pages_individually(size_t bytes, char* addr, DWORD flags,
DWORD prot,
bool should_inject_error = false) {
char * p_buf;
// note: at setup time we guaranteed that NUMAInterleaveGranularity was aligned up to a page size
size_t page_size = UseLargePages ? _large_page_size : os::vm_allocation_granularity();
size_t chunk_size = UseNUMAInterleaving ? NUMAInterleaveGranularity : page_size;
// first reserve enough address space in advance since we want to be
// able to break a single contiguous virtual address range into multiple
// large page commits but WS2003 does not allow reserving large page space
// so we just use 4K pages for reserve, this gives us a legal contiguous
// address space. then we will deallocate that reservation, and re alloc
// using large pages
const size_t size_of_reserve = bytes + chunk_size;
if (bytes > size_of_reserve) {
// Overflowed.
return NULL;
}
p_buf = (char *) VirtualAlloc(addr,
size_of_reserve, // size of Reserve
MEM_RESERVE,
PAGE_READWRITE);
// If reservation failed, return NULL
if (p_buf == NULL) return NULL;
MemTracker::record_virtual_memory_reserve((address)p_buf, size_of_reserve, CALLER_PC);
os::release_memory(p_buf, bytes + chunk_size);
// we still need to round up to a page boundary (in case we are using large pages)
// but not to a chunk boundary (in case InterleavingGranularity doesn't align with page size)
// instead we handle this in the bytes_to_rq computation below
p_buf = align_up(p_buf, page_size);
// now go through and allocate one chunk at a time until all bytes are
// allocated
size_t bytes_remaining = bytes;
// An overflow of align_up() would have been caught above
// in the calculation of size_of_reserve.
char * next_alloc_addr = p_buf;
HANDLE hProc = GetCurrentProcess();
#ifdef ASSERT
// Variable for the failure injection
int ran_num = os::random();
size_t fail_after = ran_num % bytes;
#endif
int count=0;
while (bytes_remaining) {
// select bytes_to_rq to get to the next chunk_size boundary
size_t bytes_to_rq = MIN2(bytes_remaining, chunk_size - ((size_t)next_alloc_addr % chunk_size));
// Note allocate and commit
char * p_new;
#ifdef ASSERT
bool inject_error_now = should_inject_error && (bytes_remaining <= fail_after);
#else
const bool inject_error_now = false;
#endif
if (inject_error_now) {
p_new = NULL;
} else {
if (!UseNUMAInterleaving) {
p_new = (char *) VirtualAlloc(next_alloc_addr,
bytes_to_rq,
flags,
prot);
} else {
// get the next node to use from the used_node_list
assert(numa_node_list_holder.get_count() > 0, "Multiple NUMA nodes expected");
DWORD node = numa_node_list_holder.get_node_list_entry(count % numa_node_list_holder.get_count());
p_new = (char *)VirtualAllocExNuma(hProc, next_alloc_addr, bytes_to_rq, flags, prot, node);
}
}
if (p_new == NULL) {
// Free any allocated pages
if (next_alloc_addr > p_buf) {
// Some memory was committed so release it.
size_t bytes_to_release = bytes - bytes_remaining;
// NMT has yet to record any individual blocks, so it
// need to create a dummy 'reserve' record to match
// the release.
MemTracker::record_virtual_memory_reserve((address)p_buf,
bytes_to_release, CALLER_PC);
os::release_memory(p_buf, bytes_to_release);
}
#ifdef ASSERT
if (should_inject_error) {
log_develop_debug(pagesize)("Reserving pages individually failed.");
}
#endif
return NULL;
}
bytes_remaining -= bytes_to_rq;
next_alloc_addr += bytes_to_rq;
count++;
}
// Although the memory is allocated individually, it is returned as one.
// NMT records it as one block.
if ((flags & MEM_COMMIT) != 0) {
MemTracker::record_virtual_memory_reserve_and_commit((address)p_buf, bytes, CALLER_PC);
} else {
MemTracker::record_virtual_memory_reserve((address)p_buf, bytes, CALLER_PC);
}
// made it this far, success
return p_buf;
}
void os::large_page_init() {
if (!UseLargePages) return;
// print a warning if any large page related flag is specified on command line
bool warn_on_failure = !FLAG_IS_DEFAULT(UseLargePages) ||
!FLAG_IS_DEFAULT(LargePageSizeInBytes);
bool success = false;
#define WARN(msg) if (warn_on_failure) { warning(msg); }
if (request_lock_memory_privilege()) {
size_t s = GetLargePageMinimum();
if (s) {
#if defined(IA32) || defined(AMD64)
if (s > 4*M || LargePageSizeInBytes > 4*M) {
WARN("JVM cannot use large pages bigger than 4mb.");
} else {
#endif
if (LargePageSizeInBytes && LargePageSizeInBytes % s == 0) {
_large_page_size = LargePageSizeInBytes;
} else {
_large_page_size = s;
}
success = true;
#if defined(IA32) || defined(AMD64)
}
#endif
} else {
WARN("Large page is not supported by the processor.");
}
} else {
WARN("JVM cannot use large page memory because it does not have enough privilege to lock pages in memory.");
}
#undef WARN
const size_t default_page_size = (size_t) vm_page_size();
if (success && _large_page_size > default_page_size) {
_page_sizes[0] = _large_page_size;
_page_sizes[1] = default_page_size;
_page_sizes[2] = 0;
}
cleanup_after_large_page_init();
UseLargePages = success;
}
int os::create_file_for_heap(const char* dir) {
const char name_template[] = "/jvmheap.XXXXXX";
size_t fullname_len = strlen(dir) + strlen(name_template);
char *fullname = (char*)os::malloc(fullname_len + 1, mtInternal);
if (fullname == NULL) {
vm_exit_during_initialization(err_msg("Malloc failed during creation of backing file for heap (%s)", os::strerror(errno)));
return -1;
}
int n = snprintf(fullname, fullname_len + 1, "%s%s", dir, name_template);
assert((size_t)n == fullname_len, "Unexpected number of characters in string");
os::native_path(fullname);
char *path = _mktemp(fullname);
if (path == NULL) {
warning("_mktemp could not create file name from template %s (%s)", fullname, os::strerror(errno));
os::free(fullname);
return -1;
}
int fd = _open(path, O_RDWR | O_CREAT | O_TEMPORARY | O_EXCL, S_IWRITE | S_IREAD);
os::free(fullname);
if (fd < 0) {
warning("Problem opening file for heap (%s)", os::strerror(errno));
return -1;
}
return fd;
}
// If 'base' is not NULL, function will return NULL if it cannot get 'base'
char* os::map_memory_to_file(char* base, size_t size, int fd) {
assert(fd != -1, "File descriptor is not valid");
HANDLE fh = (HANDLE)_get_osfhandle(fd);
#ifdef _LP64
HANDLE fileMapping = CreateFileMapping(fh, NULL, PAGE_READWRITE,
(DWORD)(size >> 32), (DWORD)(size & 0xFFFFFFFF), NULL);
#else
HANDLE fileMapping = CreateFileMapping(fh, NULL, PAGE_READWRITE,
0, (DWORD)size, NULL);
#endif
if (fileMapping == NULL) {
if (GetLastError() == ERROR_DISK_FULL) {
vm_exit_during_initialization(err_msg("Could not allocate sufficient disk space for Java heap"));
}
else {
vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
}
return NULL;
}
LPVOID addr = MapViewOfFileEx(fileMapping, FILE_MAP_WRITE, 0, 0, size, base);
CloseHandle(fileMapping);
return (char*)addr;
}
char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
assert(fd != -1, "File descriptor is not valid");
assert(base != NULL, "Base address cannot be NULL");
release_memory(base, size);
return map_memory_to_file(base, size, fd);
}
// On win32, one cannot release just a part of reserved memory, it's an
// all or nothing deal. When we split a reservation, we must break the
// reservation into two reservations.
void os::pd_split_reserved_memory(char *base, size_t size, size_t split,
bool realloc) {
if (size > 0) {
release_memory(base, size);
if (realloc) {
reserve_memory(split, base);
}
if (size != split) {
reserve_memory(size - split, base + split);
}
}
}
// Multiple threads can race in this code but it's not possible to unmap small sections of
// virtual space to get requested alignment, like posix-like os's.
// Windows prevents multiple thread from remapping over each other so this loop is thread-safe.
char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
"Alignment must be a multiple of allocation granularity (page size)");
assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
size_t extra_size = size + alignment;
assert(extra_size >= size, "overflow, size is too large to allow alignment");
char* aligned_base = NULL;
do {
char* extra_base = os::reserve_memory(extra_size, NULL, alignment, file_desc);
if (extra_base == NULL) {
return NULL;
}
// Do manual alignment
aligned_base = align_up(extra_base, alignment);
if (file_desc != -1) {
os::unmap_memory(extra_base, extra_size);
} else {
os::release_memory(extra_base, extra_size);
}
aligned_base = os::reserve_memory(size, aligned_base, 0, file_desc);
} while (aligned_base == NULL);
return aligned_base;
}
char* os::pd_reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
assert((size_t)addr % os::vm_allocation_granularity() == 0,
"reserve alignment");
assert(bytes % os::vm_page_size() == 0, "reserve page size");
char* res;
// note that if UseLargePages is on, all the areas that require interleaving
// will go thru reserve_memory_special rather than thru here.
bool use_individual = (UseNUMAInterleaving && !UseLargePages);
if (!use_individual) {
res = (char*)VirtualAlloc(addr, bytes, MEM_RESERVE, PAGE_READWRITE);
} else {
elapsedTimer reserveTimer;
if (Verbose && PrintMiscellaneous) reserveTimer.start();
// in numa interleaving, we have to allocate pages individually
// (well really chunks of NUMAInterleaveGranularity size)
res = allocate_pages_individually(bytes, addr, MEM_RESERVE, PAGE_READWRITE);
if (res == NULL) {
warning("NUMA page allocation failed");
}
if (Verbose && PrintMiscellaneous) {
reserveTimer.stop();
tty->print_cr("reserve_memory of %Ix bytes took " JLONG_FORMAT " ms (" JLONG_FORMAT " ticks)", bytes,
reserveTimer.milliseconds(), reserveTimer.ticks());
}
}
assert(res == NULL || addr == NULL || addr == res,
"Unexpected address from reserve.");
return res;
}
// 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) {
// Windows os::reserve_memory() fails of the requested address range is
// not avilable.
return reserve_memory(bytes, requested_addr);
}
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");
return map_memory_to_file(requested_addr, bytes, file_desc);
}
size_t os::large_page_size() {
return _large_page_size;
}
bool os::can_commit_large_page_memory() {
// Windows only uses large page memory when the entire region is reserved
// and committed in a single VirtualAlloc() call. This may change in the
// future, but with Windows 2003 it's not possible to commit on demand.
return false;
}
bool os::can_execute_large_page_memory() {
return true;
}
char* os::reserve_memory_special(size_t bytes, size_t alignment, char* addr,
bool exec) {
assert(UseLargePages, "only for large pages");
if (!is_aligned(bytes, os::large_page_size()) || alignment > os::large_page_size()) {
return NULL; // Fallback to small pages.
}
const DWORD prot = exec ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
const DWORD flags = MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES;
// with large pages, there are two cases where we need to use Individual Allocation
// 1) the UseLargePagesIndividualAllocation flag is set (set by default on WS2003)
// 2) NUMA Interleaving is enabled, in which case we use a different node for each page
if (UseLargePagesIndividualAllocation || UseNUMAInterleaving) {
log_debug(pagesize)("Reserving large pages individually.");
char * p_buf = allocate_pages_individually(bytes, addr, flags, prot, LargePagesIndividualAllocationInjectError);
if (p_buf == NULL) {
// give an appropriate warning message
if (UseNUMAInterleaving) {
warning("NUMA large page allocation failed, UseLargePages flag ignored");
}
if (UseLargePagesIndividualAllocation) {
warning("Individually allocated large pages failed, "
"use -XX:-UseLargePagesIndividualAllocation to turn off");
}
return NULL;
}
return p_buf;
} else {
log_debug(pagesize)("Reserving large pages in a single large chunk.");
// normal policy just allocate it all at once
DWORD flag = MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES;
char * res = (char *)VirtualAlloc(addr, bytes, flag, prot);
if (res != NULL) {
MemTracker::record_virtual_memory_reserve_and_commit((address)res, bytes, CALLER_PC);
}
return res;
}
}
bool os::release_memory_special(char* base, size_t bytes) {
assert(base != NULL, "Sanity check");
return release_memory(base, bytes);
}
void os::print_statistics() {
}
static void warn_fail_commit_memory(char* addr, size_t bytes, bool exec) {
int err = os::get_last_error();
char buf[256];
size_t buf_len = os::lasterror(buf, sizeof(buf));
warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
", %d) failed; error='%s' (DOS error/errno=%d)", addr, bytes,
exec, buf_len != 0 ? buf : "<no_error_string>", err);
}
bool os::pd_commit_memory(char* addr, size_t bytes, bool exec) {
if (bytes == 0) {
// Don't bother the OS with noops.
return true;
}
assert((size_t) addr % os::vm_page_size() == 0, "commit on page boundaries");
assert(bytes % os::vm_page_size() == 0, "commit in page-sized chunks");
// Don't attempt to print anything if the OS call fails. We're
// probably low on resources, so the print itself may cause crashes.
// unless we have NUMAInterleaving enabled, the range of a commit
// is always within a reserve covered by a single VirtualAlloc
// in that case we can just do a single commit for the requested size
if (!UseNUMAInterleaving) {
if (VirtualAlloc(addr, bytes, MEM_COMMIT, PAGE_READWRITE) == NULL) {
NOT_PRODUCT(warn_fail_commit_memory(addr, bytes, exec);)
return false;
}
if (exec) {
DWORD oldprot;
// Windows doc says to use VirtualProtect to get execute permissions
if (!VirtualProtect(addr, bytes, PAGE_EXECUTE_READWRITE, &oldprot)) {
NOT_PRODUCT(warn_fail_commit_memory(addr, bytes, exec);)
return false;
}
}
return true;
} else {
// when NUMAInterleaving is enabled, the commit might cover a range that
// came from multiple VirtualAlloc reserves (using allocate_pages_individually).
// VirtualQuery can help us determine that. The RegionSize that VirtualQuery
// returns represents the number of bytes that can be committed in one step.
size_t bytes_remaining = bytes;
char * next_alloc_addr = addr;
while (bytes_remaining > 0) {
MEMORY_BASIC_INFORMATION alloc_info;
VirtualQuery(next_alloc_addr, &alloc_info, sizeof(alloc_info));
size_t bytes_to_rq = MIN2(bytes_remaining, (size_t)alloc_info.RegionSize);
if (VirtualAlloc(next_alloc_addr, bytes_to_rq, MEM_COMMIT,
PAGE_READWRITE) == NULL) {
NOT_PRODUCT(warn_fail_commit_memory(next_alloc_addr, bytes_to_rq,
exec);)
return false;
}
if (exec) {
DWORD oldprot;
if (!VirtualProtect(next_alloc_addr, bytes_to_rq,
PAGE_EXECUTE_READWRITE, &oldprot)) {
NOT_PRODUCT(warn_fail_commit_memory(next_alloc_addr, bytes_to_rq,
exec);)
return false;
}
}
bytes_remaining -= bytes_to_rq;
next_alloc_addr += bytes_to_rq;
}
}
// if we made it this far, return true
return true;
}
bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
bool exec) {
// alignment_hint is ignored on this OS
return pd_commit_memory(addr, size, exec);
}
void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
const char* mesg) {
assert(mesg != NULL, "mesg must be specified");
if (!pd_commit_memory(addr, size, exec)) {
warn_fail_commit_memory(addr, size, exec);
vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
}
}
void os::pd_commit_memory_or_exit(char* addr, size_t size,
size_t alignment_hint, bool exec,
const char* mesg) {
// alignment_hint is ignored on this OS
pd_commit_memory_or_exit(addr, size, exec, mesg);
}
bool os::pd_uncommit_memory(char* addr, size_t bytes) {
if (bytes == 0) {
// Don't bother the OS with noops.
return true;
}
assert((size_t) addr % os::vm_page_size() == 0, "uncommit on page boundaries");
assert(bytes % os::vm_page_size() == 0, "uncommit in page-sized chunks");
return (VirtualFree(addr, bytes, MEM_DECOMMIT) != 0);
}
bool os::pd_release_memory(char* addr, size_t bytes) {
return VirtualFree(addr, 0, MEM_RELEASE) != 0;
}
bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
return os::commit_memory(addr, size, !ExecMem);
}
bool os::remove_stack_guard_pages(char* addr, size_t size) {
return os::uncommit_memory(addr, size);
}
static bool protect_pages_individually(char* addr, size_t bytes, unsigned int p, DWORD *old_status) {
uint count = 0;
bool ret = false;
size_t bytes_remaining = bytes;
char * next_protect_addr = addr;
// Use VirtualQuery() to get the chunk size.
while (bytes_remaining) {
MEMORY_BASIC_INFORMATION alloc_info;
if (VirtualQuery(next_protect_addr, &alloc_info, sizeof(alloc_info)) == 0) {
return false;
}
size_t bytes_to_protect = MIN2(bytes_remaining, (size_t)alloc_info.RegionSize);
// We used different API at allocate_pages_individually() based on UseNUMAInterleaving,
// but we don't distinguish here as both cases are protected by same API.
ret = VirtualProtect(next_protect_addr, bytes_to_protect, p, old_status) != 0;
warning("Failed protecting pages individually for chunk #%u", count);
if (!ret) {
return false;
}
bytes_remaining -= bytes_to_protect;
next_protect_addr += bytes_to_protect;
count++;
}
return ret;
}
// 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 = PAGE_NOACCESS; break;
case MEM_PROT_READ: p = PAGE_READONLY; break;
case MEM_PROT_RW: p = PAGE_READWRITE; break;
case MEM_PROT_RWX: p = PAGE_EXECUTE_READWRITE; break;
default:
ShouldNotReachHere();
}
DWORD old_status;
// Strange enough, but on Win32 one can change protection only for committed
// memory, not a big deal anyway, as bytes less or equal than 64K
if (!is_committed) {
commit_memory_or_exit(addr, bytes, prot == MEM_PROT_RWX,
"cannot commit protection page");
}
// One cannot use os::guard_memory() here, as on Win32 guard page
// have different (one-shot) semantics, from MSDN on PAGE_GUARD:
//
// Pages in the region become guard pages. Any attempt to access a guard page
// causes the system to raise a STATUS_GUARD_PAGE exception and turn off
// the guard page status. Guard pages thus act as a one-time access alarm.
bool ret;
if (UseNUMAInterleaving) {
// If UseNUMAInterleaving is enabled, the pages may have been allocated a chunk at a time,
// so we must protect the chunks individually.
ret = protect_pages_individually(addr, bytes, p, &old_status);
} else {
ret = VirtualProtect(addr, bytes, p, &old_status) != 0;
}
#ifdef ASSERT
if (!ret) {
int err = os::get_last_error();
char buf[256];
size_t buf_len = os::lasterror(buf, sizeof(buf));
warning("INFO: os::protect_memory(" PTR_FORMAT ", " SIZE_FORMAT
") failed; error='%s' (DOS error/errno=%d)", addr, bytes,
buf_len != 0 ? buf : "<no_error_string>", err);
}
#endif
return ret;
}
bool os::guard_memory(char* addr, size_t bytes) {
DWORD old_status;
return VirtualProtect(addr, bytes, PAGE_READWRITE | PAGE_GUARD, &old_status) != 0;
}
bool os::unguard_memory(char* addr, size_t bytes) {
DWORD old_status;
return VirtualProtect(addr, bytes, PAGE_READWRITE, &old_status) != 0;
}
void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { }
void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { }
void os::numa_make_global(char *addr, size_t bytes) { }
void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { }
bool os::numa_topology_changed() { return false; }
size_t os::numa_get_groups_num() { return MAX2(numa_node_list_holder.get_count(), 1); }
int os::numa_get_group_id() { return 0; }
size_t os::numa_get_leaf_groups(int *ids, size_t size) {
if (numa_node_list_holder.get_count() == 0 && size > 0) {
// Provide an answer for UMA systems
ids[0] = 0;
return 1;
} else {
// check for size bigger than actual groups_num
size = MIN2(size, numa_get_groups_num());
for (int i = 0; i < (int)size; i++) {
ids[i] = numa_node_list_holder.get_node_list_entry(i);
}
return size;
}
}
int os::numa_get_group_id_for_address(const void* address) {
return 0;
}
bool os::get_page_info(char *start, page_info* info) {
return false;
}
char *os::scan_pages(char *start, char* end, page_info* page_expected,
page_info* page_found) {
return end;
}
char* os::non_memory_address_word() {
// Must never look like an address returned by reserve_memory,
// even in its subfields (as defined by the CPU immediate fields,
// if the CPU splits constants across multiple instructions).
return (char*)-1;
}
#define MAX_ERROR_COUNT 100
#define SYS_THREAD_ERROR 0xffffffffUL
void os::pd_start_thread(Thread* thread) {
DWORD ret = ResumeThread(thread->osthread()->thread_handle());
// Returns previous suspend state:
// 0: Thread was not suspended
// 1: Thread is running now
// >1: Thread is still suspended.
assert(ret != SYS_THREAD_ERROR, "StartThread failed"); // should propagate back
}
// Short sleep, direct OS call.
//
// ms = 0, means allow others (if any) to run.
//
void os::naked_short_sleep(jlong ms) {
assert(ms < 1000, "Un-interruptable sleep, short time use only");
Sleep(ms);
}
// Windows does not provide sleep functionality with nanosecond resolution, so we
// try to approximate this with spinning combined with yielding if another thread
// is ready to run on the current processor.
void os::naked_short_nanosleep(jlong ns) {
assert(ns > -1 && ns < NANOUNITS, "Un-interruptable sleep, short time use only");
int64_t start = os::javaTimeNanos();
do {
if (SwitchToThread() == 0) {
// Nothing else is ready to run on this cpu, spin a little
SpinPause();
}
} while (os::javaTimeNanos() - start < ns);
}
// Sleep forever; naked call to OS-specific sleep; use with CAUTION
void os::infinite_sleep() {
while (true) { // sleep forever ...
Sleep(100000); // ... 100 seconds at a time
}
}
typedef BOOL (WINAPI * STTSignature)(void);
void os::naked_yield() {
// Consider passing back the return value from SwitchToThread().
SwitchToThread();
}
// Win32 only gives you access to seven real priorities at a time,
// so we compress Java's ten down to seven. It would be better
// if we dynamically adjusted relative priorities.
int os::java_to_os_priority[CriticalPriority + 1] = {
THREAD_PRIORITY_IDLE, // 0 Entry should never be used
THREAD_PRIORITY_LOWEST, // 1 MinPriority
THREAD_PRIORITY_LOWEST, // 2
THREAD_PRIORITY_BELOW_NORMAL, // 3
THREAD_PRIORITY_BELOW_NORMAL, // 4
THREAD_PRIORITY_NORMAL, // 5 NormPriority
THREAD_PRIORITY_NORMAL, // 6
THREAD_PRIORITY_ABOVE_NORMAL, // 7
THREAD_PRIORITY_ABOVE_NORMAL, // 8
THREAD_PRIORITY_HIGHEST, // 9 NearMaxPriority
THREAD_PRIORITY_HIGHEST, // 10 MaxPriority
THREAD_PRIORITY_HIGHEST // 11 CriticalPriority
};
int prio_policy1[CriticalPriority + 1] = {
THREAD_PRIORITY_IDLE, // 0 Entry should never be used
THREAD_PRIORITY_LOWEST, // 1 MinPriority
THREAD_PRIORITY_LOWEST, // 2
THREAD_PRIORITY_BELOW_NORMAL, // 3
THREAD_PRIORITY_BELOW_NORMAL, // 4
THREAD_PRIORITY_NORMAL, // 5 NormPriority
THREAD_PRIORITY_ABOVE_NORMAL, // 6
THREAD_PRIORITY_ABOVE_NORMAL, // 7
THREAD_PRIORITY_HIGHEST, // 8
THREAD_PRIORITY_HIGHEST, // 9 NearMaxPriority
THREAD_PRIORITY_TIME_CRITICAL, // 10 MaxPriority
THREAD_PRIORITY_TIME_CRITICAL // 11 CriticalPriority
};
static int prio_init() {
// If ThreadPriorityPolicy is 1, switch tables
if (ThreadPriorityPolicy == 1) {
int i;
for (i = 0; i < CriticalPriority + 1; i++) {
os::java_to_os_priority[i] = prio_policy1[i];
}
}
if (UseCriticalJavaThreadPriority) {
os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
}
return 0;
}
OSReturn os::set_native_priority(Thread* thread, int priority) {
if (!UseThreadPriorities) return OS_OK;
bool ret = SetThreadPriority(thread->osthread()->thread_handle(), priority) != 0;
return ret ? OS_OK : OS_ERR;
}
OSReturn os::get_native_priority(const Thread* const thread,
int* priority_ptr) {
if (!UseThreadPriorities) {
*priority_ptr = java_to_os_priority[NormPriority];
return OS_OK;
}
int os_prio = GetThreadPriority(thread->osthread()->thread_handle());
if (os_prio == THREAD_PRIORITY_ERROR_RETURN) {
assert(false, "GetThreadPriority failed");
return OS_ERR;
}
*priority_ptr = os_prio;
return OS_OK;
}
// GetCurrentThreadId() returns DWORD
intx os::current_thread_id() { return GetCurrentThreadId(); }
static int _initial_pid = 0;
int os::current_process_id() {
return (_initial_pid ? _initial_pid : _getpid());
}
int os::win32::_vm_page_size = 0;
int os::win32::_vm_allocation_granularity = 0;
int os::win32::_processor_type = 0;
// Processor level is not available on non-NT systems, use vm_version instead
int os::win32::_processor_level = 0;
julong os::win32::_physical_memory = 0;
size_t os::win32::_default_stack_size = 0;
intx os::win32::_os_thread_limit = 0;
volatile intx os::win32::_os_thread_count = 0;
bool os::win32::_is_windows_server = false;
// 6573254
// Currently, the bug is observed across all the supported Windows releases,
// including the latest one (as of this writing - Windows Server 2012 R2)
bool os::win32::_has_exit_bug = true;
void os::win32::initialize_system_info() {
SYSTEM_INFO si;
GetSystemInfo(&si);
_vm_page_size = si.dwPageSize;
_vm_allocation_granularity = si.dwAllocationGranularity;
_processor_type = si.dwProcessorType;
_processor_level = si.wProcessorLevel;
set_processor_count(si.dwNumberOfProcessors);
MEMORYSTATUSEX ms;
ms.dwLength = sizeof(ms);
// also returns dwAvailPhys (free physical memory bytes), dwTotalVirtual, dwAvailVirtual,
// dwMemoryLoad (% of memory in use)
GlobalMemoryStatusEx(&ms);
_physical_memory = ms.ullTotalPhys;
if (FLAG_IS_DEFAULT(MaxRAM)) {
// Adjust MaxRAM according to the maximum virtual address space available.
FLAG_SET_DEFAULT(MaxRAM, MIN2(MaxRAM, (uint64_t) ms.ullTotalVirtual));
}
OSVERSIONINFOEX oi;
oi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
GetVersionEx((OSVERSIONINFO*)&oi);
switch (oi.dwPlatformId) {
case VER_PLATFORM_WIN32_NT:
{
int os_vers = oi.dwMajorVersion * 1000 + oi.dwMinorVersion;
if (oi.wProductType == VER_NT_DOMAIN_CONTROLLER ||
oi.wProductType == VER_NT_SERVER) {
_is_windows_server = true;
}
}
break;
default: fatal("Unknown platform");
}
_default_stack_size = os::current_stack_size();
assert(_default_stack_size > (size_t) _vm_page_size, "invalid stack size");
assert((_default_stack_size & (_vm_page_size - 1)) == 0,
"stack size not a multiple of page size");
initialize_performance_counter();
}
HINSTANCE os::win32::load_Windows_dll(const char* name, char *ebuf,
int ebuflen) {
char path[MAX_PATH];
DWORD size;
DWORD pathLen = (DWORD)sizeof(path);
HINSTANCE result = NULL;
// only allow library name without path component
assert(strchr(name, '\\') == NULL, "path not allowed");
assert(strchr(name, ':') == NULL, "path not allowed");
if (strchr(name, '\\') != NULL || strchr(name, ':') != NULL) {
jio_snprintf(ebuf, ebuflen,
"Invalid parameter while calling os::win32::load_windows_dll(): cannot take path: %s", name);
return NULL;
}
// search system directory
if ((size = GetSystemDirectory(path, pathLen)) > 0) {
if (size >= pathLen) {
return NULL; // truncated
}
if (jio_snprintf(path + size, pathLen - size, "\\%s", name) == -1) {
return NULL; // truncated
}
if ((result = (HINSTANCE)os::dll_load(path, ebuf, ebuflen)) != NULL) {
return result;
}
}
// try Windows directory
if ((size = GetWindowsDirectory(path, pathLen)) > 0) {
if (size >= pathLen) {
return NULL; // truncated
}
if (jio_snprintf(path + size, pathLen - size, "\\%s", name) == -1) {
return NULL; // truncated
}
if ((result = (HINSTANCE)os::dll_load(path, ebuf, ebuflen)) != NULL) {
return result;
}
}
jio_snprintf(ebuf, ebuflen,
"os::win32::load_windows_dll() cannot load %s from system directories.", name);
return NULL;
}
#define MAXIMUM_THREADS_TO_KEEP (16 * MAXIMUM_WAIT_OBJECTS)
#define EXIT_TIMEOUT 300000 /* 5 minutes */
static BOOL CALLBACK init_crit_sect_call(PINIT_ONCE, PVOID pcrit_sect, PVOID*) {
InitializeCriticalSection((CRITICAL_SECTION*)pcrit_sect);
return TRUE;
}
int os::win32::exit_process_or_thread(Ept what, int exit_code) {
// Basic approach:
// - Each exiting thread registers its intent to exit and then does so.
// - A thread trying to terminate the process must wait for all
// threads currently exiting to complete their exit.
if (os::win32::has_exit_bug()) {
// The array holds handles of the threads that have started exiting by calling
// _endthreadex().
// Should be large enough to avoid blocking the exiting thread due to lack of
// a free slot.
static HANDLE handles[MAXIMUM_THREADS_TO_KEEP];
static int handle_count = 0;
static INIT_ONCE init_once_crit_sect = INIT_ONCE_STATIC_INIT;
static CRITICAL_SECTION crit_sect;
static volatile DWORD process_exiting = 0;
int i, j;
DWORD res;
HANDLE hproc, hthr;
// We only attempt to register threads until a process exiting
// thread manages to set the process_exiting flag. Any threads
// that come through here after the process_exiting flag is set
// are unregistered and will be caught in the SuspendThread()
// infinite loop below.
bool registered = false;
// The first thread that reached this point, initializes the critical section.
if (!InitOnceExecuteOnce(&init_once_crit_sect, init_crit_sect_call, &crit_sect, NULL)) {
warning("crit_sect initialization failed in %s: %d\n", __FILE__, __LINE__);
} else if (Atomic::load_acquire(&process_exiting) == 0) {
if (what != EPT_THREAD) {
// Atomically set process_exiting before the critical section
// to increase the visibility between racing threads.
Atomic::cmpxchg(&process_exiting, (DWORD)0, GetCurrentThreadId());
}
EnterCriticalSection(&crit_sect);
if (what == EPT_THREAD && Atomic::load_acquire(&process_exiting) == 0) {
// Remove from the array those handles of the threads that have completed exiting.
for (i = 0, j = 0; i < handle_count; ++i) {
res = WaitForSingleObject(handles[i], 0 /* don't wait */);
if (res == WAIT_TIMEOUT) {
handles[j++] = handles[i];
} else {
if (res == WAIT_FAILED) {
warning("WaitForSingleObject failed (%u) in %s: %d\n",
GetLastError(), __FILE__, __LINE__);
}
// Don't keep the handle, if we failed waiting for it.
CloseHandle(handles[i]);
}
}
// If there's no free slot in the array of the kept handles, we'll have to
// wait until at least one thread completes exiting.
if ((handle_count = j) == MAXIMUM_THREADS_TO_KEEP) {
// Raise the priority of the oldest exiting thread to increase its chances
// to complete sooner.
SetThreadPriority(handles[0], THREAD_PRIORITY_ABOVE_NORMAL);
res = WaitForMultipleObjects(MAXIMUM_WAIT_OBJECTS, handles, FALSE, EXIT_TIMEOUT);
if (res >= WAIT_OBJECT_0 && res < (WAIT_OBJECT_0 + MAXIMUM_WAIT_OBJECTS)) {
i = (res - WAIT_OBJECT_0);
handle_count = MAXIMUM_THREADS_TO_KEEP - 1;
for (; i < handle_count; ++i) {
handles[i] = handles[i + 1];
}
} else {
warning("WaitForMultipleObjects %s (%u) in %s: %d\n",
(res == WAIT_FAILED ? "failed" : "timed out"),
GetLastError(), __FILE__, __LINE__);
// Don't keep handles, if we failed waiting for them.
for (i = 0; i < MAXIMUM_THREADS_TO_KEEP; ++i) {
CloseHandle(handles[i]);
}
handle_count = 0;
}
}
// Store a duplicate of the current thread handle in the array of handles.
hproc = GetCurrentProcess();
hthr = GetCurrentThread();
if (!DuplicateHandle(hproc, hthr, hproc, &handles[handle_count],
0, FALSE, DUPLICATE_SAME_ACCESS)) {
warning("DuplicateHandle failed (%u) in %s: %d\n",
GetLastError(), __FILE__, __LINE__);
// We can't register this thread (no more handles) so this thread
// may be racing with a thread that is calling exit(). If the thread
// that is calling exit() has managed to set the process_exiting
// flag, then this thread will be caught in the SuspendThread()
// infinite loop below which closes that race. A small timing
// window remains before the process_exiting flag is set, but it
// is only exposed when we are out of handles.
} else {
++handle_count;
registered = true;
// The current exiting thread has stored its handle in the array, and now
// should leave the critical section before calling _endthreadex().
}
} else if (what != EPT_THREAD && handle_count > 0) {
jlong start_time, finish_time, timeout_left;
// Before ending the process, make sure all the threads that had called
// _endthreadex() completed.
// Set the priority level of the current thread to the same value as
// the priority level of exiting threads.
// This is to ensure it will be given a fair chance to execute if
// the timeout expires.
hthr = GetCurrentThread();
SetThreadPriority(hthr, THREAD_PRIORITY_ABOVE_NORMAL);
start_time = os::javaTimeNanos();
finish_time = start_time + ((jlong)EXIT_TIMEOUT * 1000000L);
for (i = 0; ; ) {
int portion_count = handle_count - i;
if (portion_count > MAXIMUM_WAIT_OBJECTS) {
portion_count = MAXIMUM_WAIT_OBJECTS;
}
for (j = 0; j < portion_count; ++j) {
SetThreadPriority(handles[i + j], THREAD_PRIORITY_ABOVE_NORMAL);
}
timeout_left = (finish_time - start_time) / 1000000L;
if (timeout_left < 0) {
timeout_left = 0;
}
res = WaitForMultipleObjects(portion_count, handles + i, TRUE, timeout_left);
if (res == WAIT_FAILED || res == WAIT_TIMEOUT) {
warning("WaitForMultipleObjects %s (%u) in %s: %d\n",
(res == WAIT_FAILED ? "failed" : "timed out"),
GetLastError(), __FILE__, __LINE__);
// Reset portion_count so we close the remaining
// handles due to this error.
portion_count = handle_count - i;
}
for (j = 0; j < portion_count; ++j) {
CloseHandle(handles[i + j]);
}
if ((i += portion_count) >= handle_count) {
break;
}
start_time = os::javaTimeNanos();
}
handle_count = 0;
}
LeaveCriticalSection(&crit_sect);
}
if (!registered &&
Atomic::load_acquire(&process_exiting) != 0 &&
process_exiting != GetCurrentThreadId()) {
// Some other thread is about to call exit(), so we don't let
// the current unregistered thread proceed to exit() or _endthreadex()
while (true) {
SuspendThread(GetCurrentThread());
// Avoid busy-wait loop, if SuspendThread() failed.
Sleep(EXIT_TIMEOUT);
}
}
}
// We are here if either
// - there's no 'race at exit' bug on this OS release;
// - initialization of the critical section failed (unlikely);
// - the current thread has registered itself and left the critical section;
// - the process-exiting thread has raised the flag and left the critical section.
if (what == EPT_THREAD) {
_endthreadex((unsigned)exit_code);
} else if (what == EPT_PROCESS) {
::exit(exit_code);
} else {
_exit(exit_code);
}
// Should not reach here
return exit_code;
}
#undef EXIT_TIMEOUT
void os::win32::setmode_streams() {
_setmode(_fileno(stdin), _O_BINARY);
_setmode(_fileno(stdout), _O_BINARY);
_setmode(_fileno(stderr), _O_BINARY);
}
void os::wait_for_keypress_at_exit(void) {
if (PauseAtExit) {
fprintf(stderr, "Press any key to continue...\n");
fgetc(stdin);
}
}
bool os::message_box(const char* title, const char* message) {
int result = MessageBox(NULL, message, title,
MB_YESNO | MB_ICONERROR | MB_SYSTEMMODAL | MB_DEFAULT_DESKTOP_ONLY);
return result == IDYES;
}
#ifndef PRODUCT
#ifndef _WIN64
// Helpers to check whether NX protection is enabled
int nx_exception_filter(_EXCEPTION_POINTERS *pex) {
if (pex->ExceptionRecord->ExceptionCode == EXCEPTION_ACCESS_VIOLATION &&
pex->ExceptionRecord->NumberParameters > 0 &&
pex->ExceptionRecord->ExceptionInformation[0] ==
EXCEPTION_INFO_EXEC_VIOLATION) {
return EXCEPTION_EXECUTE_HANDLER;
}
return EXCEPTION_CONTINUE_SEARCH;
}
void nx_check_protection() {
// If NX is enabled we'll get an exception calling into code on the stack
char code[] = { (char)0xC3 }; // ret
void *code_ptr = (void *)code;
__try {
__asm call code_ptr
} __except(nx_exception_filter((_EXCEPTION_POINTERS*)_exception_info())) {
tty->print_raw_cr("NX protection detected.");
}
}
#endif // _WIN64
#endif // PRODUCT
// This is called _before_ the global arguments have been parsed
void os::init(void) {
_initial_pid = _getpid();
init_random(1234567);
win32::initialize_system_info();
win32::setmode_streams();
init_page_sizes((size_t) win32::vm_page_size());
// This may be overridden later when argument processing is done.
FLAG_SET_ERGO(UseLargePagesIndividualAllocation, false);
// Initialize main_process and main_thread
main_process = GetCurrentProcess(); // Remember main_process is a pseudo handle
if (!DuplicateHandle(main_process, GetCurrentThread(), main_process,
&main_thread, THREAD_ALL_ACCESS, false, 0)) {
fatal("DuplicateHandle failed\n");
}
main_thread_id = (int) GetCurrentThreadId();
// initialize fast thread access - only used for 32-bit
win32::initialize_thread_ptr_offset();
}
// To install functions for atexit processing
extern "C" {
static void perfMemory_exit_helper() {
perfMemory_exit();
}
}
static jint initSock();
// this is called _after_ the global arguments have been parsed
jint os::init_2(void) {
// This could be set any time but all platforms
// have to set it the same so we have to mirror Solaris.
DEBUG_ONLY(os::set_mutex_init_done();)
// Setup Windows Exceptions
#if INCLUDE_AOT
// If AOT is enabled we need to install a vectored exception handler
// in order to forward implicit exceptions from code in AOT
// generated DLLs. This is necessary since these DLLs are not
// registered for structured exceptions like codecache methods are.
if (AOTLibrary != NULL && (UseAOT || FLAG_IS_DEFAULT(UseAOT))) {
topLevelVectoredExceptionHandler = AddVectoredExceptionHandler( 1, topLevelVectoredExceptionFilter);
}
#endif
// for debugging float code generation bugs
if (ForceFloatExceptions) {
#ifndef _WIN64
static long fp_control_word = 0;
__asm { fstcw fp_control_word }
// see Intel PPro Manual, Vol. 2, p 7-16
const long precision = 0x20;
const long underflow = 0x10;
const long overflow = 0x08;
const long zero_div = 0x04;
const long denorm = 0x02;
const long invalid = 0x01;
fp_control_word |= invalid;
__asm { fldcw fp_control_word }
#endif
}
// If stack_commit_size is 0, windows will reserve the default size,
// but only commit a small portion of it.
size_t stack_commit_size = align_up(ThreadStackSize*K, os::vm_page_size());
size_t default_reserve_size = os::win32::default_stack_size();
size_t actual_reserve_size = stack_commit_size;
if (stack_commit_size < default_reserve_size) {
// If stack_commit_size == 0, we want this too
actual_reserve_size = default_reserve_size;
}
// Check minimum allowable stack size for thread creation and to initialize
// the java system classes, including StackOverflowError - depends on page
// size. Add two 4K pages for compiler2 recursion in main thread.
// Add in 4*BytesPerWord 4K pages to account for VM stack during
// class initialization depending on 32 or 64 bit VM.
size_t min_stack_allowed =
(size_t)(JavaThread::stack_guard_zone_size() +
JavaThread::stack_shadow_zone_size() +
(4*BytesPerWord COMPILER2_PRESENT(+2)) * 4 * K);
min_stack_allowed = align_up(min_stack_allowed, os::vm_page_size());
if (actual_reserve_size < min_stack_allowed) {
tty->print_cr("\nThe Java thread stack size specified is too small. "
"Specify at least %dk",
min_stack_allowed / K);
return JNI_ERR;
}
JavaThread::set_stack_size_at_create(stack_commit_size);
// Calculate theoretical max. size of Threads to guard gainst artifical
// out-of-memory situations, where all available address-space has been
// reserved by thread stacks.
assert(actual_reserve_size != 0, "Must have a stack");
// Calculate the thread limit when we should start doing Virtual Memory
// banging. Currently when the threads will have used all but 200Mb of space.
//
// TODO: consider performing a similar calculation for commit size instead
// as reserve size, since on a 64-bit platform we'll run into that more
// often than running out of virtual memory space. We can use the
// lower value of the two calculations as the os_thread_limit.
size_t max_address_space = ((size_t)1 << (BitsPerWord - 1)) - (200 * K * K);
win32::_os_thread_limit = (intx)(max_address_space / actual_reserve_size);
// at exit methods are called in the reverse order of their registration.
// there is no limit to the number of functions registered. 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");
}
}
#ifndef _WIN64
// Print something if NX is enabled (win32 on AMD64)
NOT_PRODUCT(if (PrintMiscellaneous && Verbose) nx_check_protection());
#endif
// initialize thread priority policy
prio_init();
if (UseNUMA && !ForceNUMA) {
UseNUMA = false; // We don't fully support this yet
}
if (UseNUMAInterleaving) {
// first check whether this Windows OS supports VirtualAllocExNuma, if not ignore this flag
bool success = numa_interleaving_init();
if (!success) UseNUMAInterleaving = false;
}
if (initSock() != JNI_OK) {
return JNI_ERR;
}
SymbolEngine::recalc_search_path();
// Initialize data for jdk.internal.misc.Signal
if (!ReduceSignalUsage) {
jdk_misc_signal_init();
}
return JNI_OK;
}
// Mark the polling page as unreadable
void os::make_polling_page_unreadable(void) {
DWORD old_status;
if (!VirtualProtect((char *)_polling_page, os::vm_page_size(),
PAGE_NOACCESS, &old_status)) {
fatal("Could not disable polling page");
}
}
// Mark the polling page as readable
void os::make_polling_page_readable(void) {
DWORD old_status;
if (!VirtualProtect((char *)_polling_page, os::vm_page_size(),
PAGE_READONLY, &old_status)) {
fatal("Could not enable polling page");
}
}
// combine the high and low DWORD into a ULONGLONG
static ULONGLONG make_double_word(DWORD high_word, DWORD low_word) {
ULONGLONG value = high_word;
value <<= sizeof(high_word) * 8;
value |= low_word;
return value;
}
// Transfers data from WIN32_FILE_ATTRIBUTE_DATA structure to struct stat
static void file_attribute_data_to_stat(struct stat* sbuf, WIN32_FILE_ATTRIBUTE_DATA file_data) {
::memset((void*)sbuf, 0, sizeof(struct stat));
sbuf->st_size = (_off_t)make_double_word(file_data.nFileSizeHigh, file_data.nFileSizeLow);
sbuf->st_mtime = make_double_word(file_data.ftLastWriteTime.dwHighDateTime,
file_data.ftLastWriteTime.dwLowDateTime);
sbuf->st_ctime = make_double_word(file_data.ftCreationTime.dwHighDateTime,
file_data.ftCreationTime.dwLowDateTime);
sbuf->st_atime = make_double_word(file_data.ftLastAccessTime.dwHighDateTime,
file_data.ftLastAccessTime.dwLowDateTime);
if ((file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0) {
sbuf->st_mode |= S_IFDIR;
} else {
sbuf->st_mode |= S_IFREG;
}
}
// Returns the given path as an absolute wide path in unc format. The returned path is NULL
// on error (with err being set accordingly) and should be freed via os::free() otherwise.
// additional_space is the number of additionally allocated wchars after the terminating L'\0'.
// This is based on pathToNTPath() in io_util_md.cpp, but omits the optimizations for
// short paths.
static wchar_t* wide_abs_unc_path(char const* path, errno_t & err, int additional_space = 0) {
if ((path == NULL) || (path[0] == '\0')) {
err = ENOENT;
return NULL;
}
size_t path_len = strlen(path);
// Need to allocate at least room for 3 characters, since os::native_path transforms C: to C:.
char* buf = (char*) os::malloc(1 + MAX2((size_t) 3, path_len), mtInternal);
wchar_t* result = NULL;
if (buf == NULL) {
err = ENOMEM;
} else {
memcpy(buf, path, path_len + 1);
os::native_path(buf);
wchar_t* prefix;
int prefix_off = 0;
bool is_abs = true;
bool needs_fullpath = true;
if (::isalpha(buf[0]) && !::IsDBCSLeadByte(buf[0]) && buf[1] == ':' && buf[2] == '\\') {
prefix = L"\\\\?\\";
} else if (buf[0] == '\\' && buf[1] == '\\') {
if (buf[2] == '?' && buf[3] == '\\') {
prefix = L"";
needs_fullpath = false;
} else {
prefix = L"\\\\?\\UNC";
prefix_off = 1; // Overwrite the first char with the prefix, so \\share\path becomes \\?\UNC\share\path
}
} else {
is_abs = false;
prefix = L"\\\\?\\";
}
size_t buf_len = strlen(buf);
size_t prefix_len = wcslen(prefix);
size_t full_path_size = is_abs ? 1 + buf_len : JVM_MAXPATHLEN;
size_t result_size = prefix_len + full_path_size - prefix_off;
result = (wchar_t*) os::malloc(sizeof(wchar_t) * (additional_space + result_size), mtInternal);
if (result == NULL) {
err = ENOMEM;
} else {
size_t converted_chars;
wchar_t* path_start = result + prefix_len - prefix_off;
err = ::mbstowcs_s(&converted_chars, path_start, buf_len + 1, buf, buf_len);
if ((err == ERROR_SUCCESS) && needs_fullpath) {
wchar_t* tmp = (wchar_t*) os::malloc(sizeof(wchar_t) * full_path_size, mtInternal);
if (tmp == NULL) {
err = ENOMEM;
} else {
if (!_wfullpath(tmp, path_start, full_path_size)) {
err = ENOENT;
} else {
::memcpy(path_start, tmp, (1 + wcslen(tmp)) * sizeof(wchar_t));
}
os::free(tmp);
}
}
memcpy(result, prefix, sizeof(wchar_t) * prefix_len);
// Remove trailing pathsep (not for \\?\<DRIVE>:\, since it would make it relative)
size_t result_len = wcslen(result);
if (result[result_len - 1] == L'\\') {
if (!(::iswalpha(result[4]) && result[5] == L':' && result_len == 7)) {
result[result_len - 1] = L'\0';
}
}
}
}
os::free(buf);
if (err != ERROR_SUCCESS) {
os::free(result);
result = NULL;
}
return result;
}
int os::stat(const char *path, struct stat *sbuf) {
errno_t err;
wchar_t* wide_path = wide_abs_unc_path(path, err);
if (wide_path == NULL) {
errno = err;
return -1;
}
WIN32_FILE_ATTRIBUTE_DATA file_data;;
BOOL bret = ::GetFileAttributesExW(wide_path, GetFileExInfoStandard, &file_data);
os::free(wide_path);
if (!bret) {
errno = ::GetLastError();
return -1;
}
file_attribute_data_to_stat(sbuf, file_data);
return 0;
}
static HANDLE create_read_only_file_handle(const char* file) {
errno_t err;
wchar_t* wide_path = wide_abs_unc_path(file, err);
if (wide_path == NULL) {
errno = err;
return INVALID_HANDLE_VALUE;
}
HANDLE handle = ::CreateFileW(wide_path, 0, FILE_SHARE_READ,
NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
os::free(wide_path);
return handle;
}
bool os::same_files(const char* file1, const char* file2) {
if (file1 == NULL && file2 == NULL) {
return true;
}
if (file1 == NULL || file2 == NULL) {
return false;
}
if (strcmp(file1, file2) == 0) {
return true;
}
HANDLE handle1 = create_read_only_file_handle(file1);
HANDLE handle2 = create_read_only_file_handle(file2);
bool result = false;
// if we could open both paths...
if (handle1 != INVALID_HANDLE_VALUE && handle2 != INVALID_HANDLE_VALUE) {
BY_HANDLE_FILE_INFORMATION fileInfo1;
BY_HANDLE_FILE_INFORMATION fileInfo2;
if (::GetFileInformationByHandle(handle1, &fileInfo1) &&
::GetFileInformationByHandle(handle2, &fileInfo2)) {
// the paths are the same if they refer to the same file (fileindex) on the same volume (volume serial number)
if (fileInfo1.dwVolumeSerialNumber == fileInfo2.dwVolumeSerialNumber &&
fileInfo1.nFileIndexHigh == fileInfo2.nFileIndexHigh &&
fileInfo1.nFileIndexLow == fileInfo2.nFileIndexLow) {
result = true;
}
}
}
//free the handles
if (handle1 != INVALID_HANDLE_VALUE) {
::CloseHandle(handle1);
}
if (handle2 != INVALID_HANDLE_VALUE) {
::CloseHandle(handle2);
}
return result;
}
#define FT2INT64(ft) \
((jlong)((jlong)(ft).dwHighDateTime << 32 | (julong)(ft).dwLowDateTime))
// 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.
// current_thread_cpu_time() is not optimized for Windows yet
jlong os::current_thread_cpu_time() {
// return user + sys since the cost is the same
return os::thread_cpu_time(Thread::current(), true /* user+sys */);
}
jlong os::thread_cpu_time(Thread* thread) {
// consistent with what current_thread_cpu_time() returns.
return os::thread_cpu_time(thread, true /* user+sys */);
}
jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
}
jlong os::thread_cpu_time(Thread* thread, bool user_sys_cpu_time) {
// This code is copy from clasic VM -> hpi::sysThreadCPUTime
// If this function changes, os::is_thread_cpu_time_supported() should too
FILETIME CreationTime;
FILETIME ExitTime;
FILETIME KernelTime;
FILETIME UserTime;
if (GetThreadTimes(thread->osthread()->thread_handle(), &CreationTime,
&ExitTime, &KernelTime, &UserTime) == 0) {
return -1;
} else if (user_sys_cpu_time) {
return (FT2INT64(UserTime) + FT2INT64(KernelTime)) * 100;
} else {
return FT2INT64(UserTime) * 100;
}
}
void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
info_ptr->max_value = ALL_64_BITS; // the max value -- all 64 bits
info_ptr->may_skip_backward = false; // GetThreadTimes returns absolute time
info_ptr->may_skip_forward = false; // GetThreadTimes returns absolute 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; // the max value -- all 64 bits
info_ptr->may_skip_backward = false; // GetThreadTimes returns absolute time
info_ptr->may_skip_forward = false; // GetThreadTimes returns absolute time
info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
}
bool os::is_thread_cpu_time_supported() {
// see os::thread_cpu_time
FILETIME CreationTime;
FILETIME ExitTime;
FILETIME KernelTime;
FILETIME UserTime;
if (GetThreadTimes(GetCurrentThread(), &CreationTime, &ExitTime,
&KernelTime, &UserTime) == 0) {
return false;
} else {
return true;
}
}
// Windows does't provide a loadavg primitive so this is stubbed out for now.
// It does have primitives (PDH API) to get CPU usage and run queue length.
// "\\Processor(_Total)\\% Processor Time", "\\System\\Processor Queue Length"
// If we wanted to implement loadavg on Windows, we have a few options:
//
// a) Query CPU usage and run queue length and "fake" an answer by
// returning the CPU usage if it's under 100%, and the run queue
// length otherwise. It turns out that querying is pretty slow
// on Windows, on the order of 200 microseconds on a fast machine.
// Note that on the Windows the CPU usage value is the % usage
// since the last time the API was called (and the first call
// returns 100%), so we'd have to deal with that as well.
//
// b) Sample the "fake" answer using a sampling thread and store
// the answer in a global variable. The call to loadavg would
// just return the value of the global, avoiding the slow query.
//
// c) Sample a better answer using exponential decay to smooth the
// value. This is basically the algorithm used by UNIX kernels.
//
// Note that sampling thread starvation could affect both (b) and (c).
int os::loadavg(double loadavg[], int nelem) {
return -1;
}
// DontYieldALot=false by default: dutifully perform all yields as requested by JVM_Yield()
bool os::dont_yield() {
return DontYieldALot;
}
int os::open(const char *path, int oflag, int mode) {
errno_t err;
wchar_t* wide_path = wide_abs_unc_path(path, err);
if (wide_path == NULL) {
errno = err;
return -1;
}
int fd = ::_wopen(wide_path, oflag | O_BINARY | O_NOINHERIT, mode);
os::free(wide_path);
if (fd == -1) {
errno = ::GetLastError();
}
return fd;
}
FILE* os::open(int fd, const char* mode) {
return ::_fdopen(fd, mode);
}
// Is a (classpath) directory empty?
bool os::dir_is_empty(const char* path) {
errno_t err;
wchar_t* wide_path = wide_abs_unc_path(path, err, 2);
if (wide_path == NULL) {
errno = err;
return false;
}
// Make sure we end with "\\*"
if (wide_path[wcslen(wide_path) - 1] == L'\\') {
wcscat(wide_path, L"*");
} else {
wcscat(wide_path, L"\\*");
}
WIN32_FIND_DATAW fd;
HANDLE f = ::FindFirstFileW(wide_path, &fd);
os::free(wide_path);
bool is_empty = true;
if (f != INVALID_HANDLE_VALUE) {
while (is_empty && ::FindNextFileW(f, &fd)) {
// An empty directory contains only the current directory file
// and the previous directory file.
if ((wcscmp(fd.cFileName, L".") != 0) &&
(wcscmp(fd.cFileName, L"..") != 0)) {
is_empty = false;
}
}
FindClose(f);
} else {
errno = ::GetLastError();
}
return is_empty;
}
// create binary file, rewriting existing file if required
int os::create_binary_file(const char* path, bool rewrite_existing) {
int oflags = _O_CREAT | _O_WRONLY | _O_BINARY;
if (!rewrite_existing) {
oflags |= _O_EXCL;
}
return ::open(path, oflags, _S_IREAD | _S_IWRITE);
}
// return current position of file pointer
jlong os::current_file_offset(int fd) {
return (jlong)::_lseeki64(fd, (__int64)0L, SEEK_CUR);
}
// move file pointer to the specified offset
jlong os::seek_to_file_offset(int fd, jlong offset) {
return (jlong)::_lseeki64(fd, (__int64)offset, SEEK_SET);
}
jlong os::lseek(int fd, jlong offset, int whence) {
return (jlong) ::_lseeki64(fd, offset, whence);
}
ssize_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
OVERLAPPED ov;
DWORD nread;
BOOL result;
ZeroMemory(&ov, sizeof(ov));
ov.Offset = (DWORD)offset;
ov.OffsetHigh = (DWORD)(offset >> 32);
HANDLE h = (HANDLE)::_get_osfhandle(fd);
result = ReadFile(h, (LPVOID)buf, nBytes, &nread, &ov);
return result ? nread : 0;
}
// This method is a slightly reworked copy of JDK's sysNativePath
// from src/windows/hpi/src/path_md.c
// Convert a pathname to native format. On win32, this involves forcing all
// separators to be '\\' rather than '/' (both are legal inputs, but Win95
// sometimes rejects '/') and removing redundant separators. The input path is
// assumed to have been converted into the character encoding used by the local
// system. Because this might be a double-byte encoding, care is taken to
// treat double-byte lead characters correctly.
//
// This procedure modifies the given path in place, as the result is never
// longer than the original. There is no error return; this operation always
// succeeds.
char * os::native_path(char *path) {
char *src = path, *dst = path, *end = path;
char *colon = NULL; // If a drive specifier is found, this will
// point to the colon following the drive letter
// Assumption: '/', '\\', ':', and drive letters are never lead bytes
assert(((!::IsDBCSLeadByte('/')) && (!::IsDBCSLeadByte('\\'))
&& (!::IsDBCSLeadByte(':'))), "Illegal lead byte");
// Check for leading separators
#define isfilesep(c) ((c) == '/' || (c) == '\\')
while (isfilesep(*src)) {
src++;
}
if (::isalpha(*src) && !::IsDBCSLeadByte(*src) && src[1] == ':') {
// Remove leading separators if followed by drive specifier. This
// hack is necessary to support file URLs containing drive
// specifiers (e.g., "file://c:/path"). As a side effect,
// "/c:/path" can be used as an alternative to "c:/path".
*dst++ = *src++;
colon = dst;
*dst++ = ':';
src++;
} else {
src = path;
if (isfilesep(src[0]) && isfilesep(src[1])) {
// UNC pathname: Retain first separator; leave src pointed at
// second separator so that further separators will be collapsed
// into the second separator. The result will be a pathname
// beginning with "\\\\" followed (most likely) by a host name.
src = dst = path + 1;
path[0] = '\\'; // Force first separator to '\\'
}
}
end = dst;
// Remove redundant separators from remainder of path, forcing all
// separators to be '\\' rather than '/'. Also, single byte space
// characters are removed from the end of the path because those
// are not legal ending characters on this operating system.
//
while (*src != '\0') {
if (isfilesep(*src)) {
*dst++ = '\\'; src++;
while (isfilesep(*src)) src++;
if (*src == '\0') {
// Check for trailing separator
end = dst;
if (colon == dst - 2) break; // "z:\\"
if (dst == path + 1) break; // "\\"
if (dst == path + 2 && isfilesep(path[0])) {
// "\\\\" is not collapsed to "\\" because "\\\\" marks the
// beginning of a UNC pathname. Even though it is not, by
// itself, a valid UNC pathname, we leave it as is in order
// to be consistent with the path canonicalizer as well
// as the win32 APIs, which treat this case as an invalid
// UNC pathname rather than as an alias for the root
// directory of the current drive.
break;
}
end = --dst; // Path does not denote a root directory, so
// remove trailing separator
break;
}
end = dst;
} else {
if (::IsDBCSLeadByte(*src)) { // Copy a double-byte character
*dst++ = *src++;
if (*src) *dst++ = *src++;
end = dst;
} else { // Copy a single-byte character
char c = *src++;
*dst++ = c;
// Space is not a legal ending character
if (c != ' ') end = dst;
}
}
}
*end = '\0';
// For "z:", add "." to work around a bug in the C runtime library
if (colon == dst - 1) {
path[2] = '.';
path[3] = '\0';
}
return path;
}
// This code is a copy of JDK's sysSetLength
// from src/windows/hpi/src/sys_api_md.c
int os::ftruncate(int fd, jlong length) {
HANDLE h = (HANDLE)::_get_osfhandle(fd);
long high = (long)(length >> 32);
DWORD ret;
if (h == (HANDLE)(-1)) {
return -1;
}
ret = ::SetFilePointer(h, (long)(length), &high, FILE_BEGIN);
if ((ret == 0xFFFFFFFF) && (::GetLastError() != NO_ERROR)) {
return -1;
}
if (::SetEndOfFile(h) == FALSE) {
return -1;
}
return 0;
}
int os::get_fileno(FILE* fp) {
return _fileno(fp);
}
// This code is a copy of JDK's sysSync
// from src/windows/hpi/src/sys_api_md.c
// except for the legacy workaround for a bug in Win 98
int os::fsync(int fd) {
HANDLE handle = (HANDLE)::_get_osfhandle(fd);
if ((!::FlushFileBuffers(handle)) &&
(GetLastError() != ERROR_ACCESS_DENIED)) {
// from winerror.h
return -1;
}
return 0;
}
static int nonSeekAvailable(int, long *);
static int stdinAvailable(int, long *);
// This code is a copy of JDK's sysAvailable
// from src/windows/hpi/src/sys_api_md.c
int os::available(int fd, jlong *bytes) {
jlong cur, end;
struct _stati64 stbuf64;
if (::_fstati64(fd, &stbuf64) >= 0) {
int mode = stbuf64.st_mode;
if (S_ISCHR(mode) || S_ISFIFO(mode)) {
int ret;
long lpbytes;
if (fd == 0) {
ret = stdinAvailable(fd, &lpbytes);
} else {
ret = nonSeekAvailable(fd, &lpbytes);
}
(*bytes) = (jlong)(lpbytes);
return ret;
}
if ((cur = ::_lseeki64(fd, 0L, SEEK_CUR)) == -1) {
return FALSE;
} else if ((end = ::_lseeki64(fd, 0L, SEEK_END)) == -1) {
return FALSE;
} else if (::_lseeki64(fd, cur, SEEK_SET) == -1) {
return FALSE;
}
*bytes = end - cur;
return TRUE;
} else {
return FALSE;
}
}
void os::flockfile(FILE* fp) {
_lock_file(fp);
}
void os::funlockfile(FILE* fp) {
_unlock_file(fp);
}
// This code is a copy of JDK's nonSeekAvailable
// from src/windows/hpi/src/sys_api_md.c
static int nonSeekAvailable(int fd, long *pbytes) {
// This is used for available on non-seekable devices
// (like both named and anonymous pipes, such as pipes
// connected to an exec'd process).
// Standard Input is a special case.
HANDLE han;
if ((han = (HANDLE) ::_get_osfhandle(fd)) == (HANDLE)(-1)) {
return FALSE;
}
if (! ::PeekNamedPipe(han, NULL, 0, NULL, (LPDWORD)pbytes, NULL)) {
// PeekNamedPipe fails when at EOF. In that case we
// simply make *pbytes = 0 which is consistent with the
// behavior we get on Solaris when an fd is at EOF.
// The only alternative is to raise an Exception,
// which isn't really warranted.
//
if (::GetLastError() != ERROR_BROKEN_PIPE) {
return FALSE;
}
*pbytes = 0;
}
return TRUE;
}
#define MAX_INPUT_EVENTS 2000
// This code is a copy of JDK's stdinAvailable
// from src/windows/hpi/src/sys_api_md.c
static int stdinAvailable(int fd, long *pbytes) {
HANDLE han;
DWORD numEventsRead = 0; // Number of events read from buffer
DWORD numEvents = 0; // Number of events in buffer
DWORD i = 0; // Loop index
DWORD curLength = 0; // Position marker
DWORD actualLength = 0; // Number of bytes readable
BOOL error = FALSE; // Error holder
INPUT_RECORD *lpBuffer; // Pointer to records of input events
if ((han = ::GetStdHandle(STD_INPUT_HANDLE)) == INVALID_HANDLE_VALUE) {
return FALSE;
}
// Construct an array of input records in the console buffer
error = ::GetNumberOfConsoleInputEvents(han, &numEvents);
if (error == 0) {
return nonSeekAvailable(fd, pbytes);
}
// lpBuffer must fit into 64K or else PeekConsoleInput fails
if (numEvents > MAX_INPUT_EVENTS) {
numEvents = MAX_INPUT_EVENTS;
}
lpBuffer = (INPUT_RECORD *)os::malloc(numEvents * sizeof(INPUT_RECORD), mtInternal);
if (lpBuffer == NULL) {
return FALSE;
}
error = ::PeekConsoleInput(han, lpBuffer, numEvents, &numEventsRead);
if (error == 0) {
os::free(lpBuffer);
return FALSE;
}
// Examine input records for the number of bytes available
for (i=0; i<numEvents; i++) {
if (lpBuffer[i].EventType == KEY_EVENT) {
KEY_EVENT_RECORD *keyRecord = (KEY_EVENT_RECORD *)
&(lpBuffer[i].Event);
if (keyRecord->bKeyDown == TRUE) {
CHAR *keyPressed = (CHAR *) &(keyRecord->uChar);
curLength++;
if (*keyPressed == '\r') {
actualLength = curLength;
}
}
}
}
if (lpBuffer != NULL) {
os::free(lpBuffer);
}
*pbytes = (long) actualLength;
return TRUE;
}
// 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) {
HANDLE hFile;
char* base;
hFile = CreateFile(file_name, GENERIC_READ, FILE_SHARE_READ, NULL,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if (hFile == NULL) {
log_info(os)("CreateFile() failed: GetLastError->%ld.", GetLastError());
return NULL;
}
if (allow_exec) {
// CreateFileMapping/MapViewOfFileEx can't map executable memory
// unless it comes from a PE image (which the shared archive is not.)
// Even VirtualProtect refuses to give execute access to mapped memory
// that was not previously executable.
//
// Instead, stick the executable region in anonymous memory. Yuck.
// Penalty is that ~4 pages will not be shareable - in the future
// we might consider DLLizing the shared archive with a proper PE
// header so that mapping executable + sharing is possible.
base = (char*) VirtualAlloc(addr, bytes, MEM_COMMIT | MEM_RESERVE,
PAGE_READWRITE);
if (base == NULL) {
log_info(os)("VirtualAlloc() failed: GetLastError->%ld.", GetLastError());
CloseHandle(hFile);
return NULL;
}
// Record virtual memory allocation
MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
DWORD bytes_read;
OVERLAPPED overlapped;
overlapped.Offset = (DWORD)file_offset;
overlapped.OffsetHigh = 0;
overlapped.hEvent = NULL;
// ReadFile guarantees that if the return value is true, the requested
// number of bytes were read before returning.
bool res = ReadFile(hFile, base, (DWORD)bytes, &bytes_read, &overlapped) != 0;
if (!res) {
log_info(os)("ReadFile() failed: GetLastError->%ld.", GetLastError());
release_memory(base, bytes);
CloseHandle(hFile);
return NULL;
}
} else {
HANDLE hMap = CreateFileMapping(hFile, NULL, PAGE_WRITECOPY, 0, 0,
NULL /* file_name */);
if (hMap == NULL) {
log_info(os)("CreateFileMapping() failed: GetLastError->%ld.", GetLastError());
CloseHandle(hFile);
return NULL;
}
DWORD access = read_only ? FILE_MAP_READ : FILE_MAP_COPY;
base = (char*)MapViewOfFileEx(hMap, access, 0, (DWORD)file_offset,
(DWORD)bytes, addr);
if (base == NULL) {
log_info(os)("MapViewOfFileEx() failed: GetLastError->%ld.", GetLastError());
CloseHandle(hMap);
CloseHandle(hFile);
return NULL;
}
if (CloseHandle(hMap) == 0) {
log_info(os)("CloseHandle(hMap) failed: GetLastError->%ld.", GetLastError());
CloseHandle(hFile);
return base;
}
}
if (allow_exec) {
DWORD old_protect;
DWORD exec_access = read_only ? PAGE_EXECUTE_READ : PAGE_EXECUTE_READWRITE;
bool res = VirtualProtect(base, bytes, exec_access, &old_protect) != 0;
if (!res) {
log_info(os)("VirtualProtect() failed: GetLastError->%ld.", GetLastError());
// Don't consider this a hard error, on IA32 even if the
// VirtualProtect fails, we should still be able to execute
CloseHandle(hFile);
return base;
}
}
if (CloseHandle(hFile) == 0) {
log_info(os)("CloseHandle(hFile) failed: GetLastError->%ld.", GetLastError());
return base;
}
return base;
}
// 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) {
// This OS does not allow existing memory maps to be remapped so we
// would have to unmap the memory before we remap it.
// Because there is a small window between unmapping memory and mapping
// it in again with different protections, CDS archives are mapped RW
// on windows, so this function isn't called.
ShouldNotReachHere();
return NULL;
}
// Unmap a block of memory.
// Returns true=success, otherwise false.
bool os::pd_unmap_memory(char* addr, size_t bytes) {
MEMORY_BASIC_INFORMATION mem_info;
if (VirtualQuery(addr, &mem_info, sizeof(mem_info)) == 0) {
log_info(os)("VirtualQuery() failed: GetLastError->%ld.", GetLastError());
return false;
}
// Executable memory was not mapped using CreateFileMapping/MapViewOfFileEx.
// Instead, executable region was allocated using VirtualAlloc(). See
// pd_map_memory() above.
//
// The following flags should match the 'exec_access' flages used for
// VirtualProtect() in pd_map_memory().
if (mem_info.Protect == PAGE_EXECUTE_READ ||
mem_info.Protect == PAGE_EXECUTE_READWRITE) {
return pd_release_memory(addr, bytes);
}
BOOL result = UnmapViewOfFile(addr);
if (result == 0) {
log_info(os)("UnmapViewOfFile() failed: GetLastError->%ld.", GetLastError());
return false;
}
return true;
}
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) {
Sleep(100);
}
} else {
jio_fprintf(stderr,
"Could not open pause file '%s', continuing immediately.\n", filename);
}
}
Thread* os::ThreadCrashProtection::_protected_thread = NULL;
os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
os::ThreadCrashProtection::ThreadCrashProtection() {
}
// See the caveats for this class in os_windows.hpp
// Protects the callback call so that raised OS EXCEPTIONS causes a jump back
// into this method and returns false. If no OS EXCEPTION was raised, returns
// true.
// The callback is supposed to provide the method that should be protected.
//
bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
Thread::muxAcquire(&_crash_mux, "CrashProtection");
_protected_thread = Thread::current_or_null();
assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
bool success = true;
__try {
_crash_protection = this;
cb.call();
} __except(EXCEPTION_EXECUTE_HANDLER) {
// only for protection, nothing to do
success = false;
}
_crash_protection = NULL;
_protected_thread = NULL;
Thread::muxRelease(&_crash_mux);
return success;
}
class HighResolutionInterval : public CHeapObj<mtThread> {
// The default timer resolution seems to be 10 milliseconds.
// (Where is this written down?)
// If someone wants to sleep for only a fraction of the default,
// then we set the timer resolution down to 1 millisecond for
// the duration of their interval.
// We carefully set the resolution back, since otherwise we
// seem to incur an overhead (3%?) that we don't need.
// CONSIDER: if ms is small, say 3, then we should run with a high resolution time.
// Buf if ms is large, say 500, or 503, we should avoid the call to timeBeginPeriod().
// Alternatively, we could compute the relative error (503/500 = .6%) and only use
// timeBeginPeriod() if the relative error exceeded some threshold.
// timeBeginPeriod() has been linked to problems with clock drift on win32 systems and
// to decreased efficiency related to increased timer "tick" rates. We want to minimize
// (a) calls to timeBeginPeriod() and timeEndPeriod() and (b) time spent with high
// resolution timers running.
private:
jlong resolution;
public:
HighResolutionInterval(jlong ms) {
resolution = ms % 10L;
if (resolution != 0) {
MMRESULT result = timeBeginPeriod(1L);
}
}
~HighResolutionInterval() {
if (resolution != 0) {
MMRESULT result = timeEndPeriod(1L);
}
resolution = 0L;
}
};
// An Event wraps a win32 "CreateEvent" kernel handle.
//
// We have a number of choices regarding "CreateEvent" win32 handle leakage:
//
// 1: When a thread dies return the Event to the EventFreeList, clear the ParkHandle
// field, and call CloseHandle() on the win32 event handle. Unpark() would
// need to be modified to tolerate finding a NULL (invalid) win32 event handle.
// In addition, an unpark() operation might fetch the handle field, but the
// event could recycle between the fetch and the SetEvent() operation.
// SetEvent() would either fail because the handle was invalid, or inadvertently work,
// as the win32 handle value had been recycled. In an ideal world calling SetEvent()
// on an stale but recycled handle would be harmless, but in practice this might
// confuse other non-Sun code, so it's not a viable approach.
//
// 2: Once a win32 event handle is associated with an Event, it remains associated
// with the Event. The event handle is never closed. This could be construed
// as handle leakage, but only up to the maximum # of threads that have been extant
// at any one time. This shouldn't be an issue, as windows platforms typically
// permit a process to have hundreds of thousands of open handles.
//
// 3: Same as (1), but periodically, at stop-the-world time, rundown the EventFreeList
// and release unused handles.
//
// 4: Add a CRITICAL_SECTION to the Event to protect LD+SetEvent from LD;ST(null);CloseHandle.
// It's not clear, however, that we wouldn't be trading one type of leak for another.
//
// 5. Use an RCU-like mechanism (Read-Copy Update).
// Or perhaps something similar to Maged Michael's "Hazard pointers".
//
// We use (2).
//
// TODO-FIXME:
// 1. Reconcile Doug's JSR166 j.u.c park-unpark with the objectmonitor implementation.
// 2. Consider wrapping the WaitForSingleObject(Ex) calls in SEH try/finally blocks
// to recover from (or at least detect) the dreaded Windows 841176 bug.
// 3. Collapse the JSR166 parker event, and the objectmonitor ParkEvent
// into a single win32 CreateEvent() handle.
//
// Assumption:
// Only one parker can exist on an event, which is why we allocate
// them per-thread. Multiple unparkers can coexist.
//
// _Event transitions in park()
// -1 => -1 : illegal
// 1 => 0 : pass - return immediately
// 0 => -1 : block; then set _Event to 0 before returning
//
// _Event transitions in unpark()
// 0 => 1 : just return
// 1 => 1 : just return
// -1 => either 0 or 1; must signal target thread
// That is, we can safely transition _Event from -1 to either
// 0 or 1.
//
// _Event serves as a restricted-range semaphore.
// -1 : thread is blocked, i.e. there is a waiter
// 0 : neutral: thread is running or ready,
// could have been signaled after a wait started
// 1 : signaled - thread is running or ready
//
// Another possible encoding of _Event would be with
// explicit "PARKED" == 01b and "SIGNALED" == 10b bits.
//
/**代码未完, 请加载全部代码(NowJava.com).**/
关注时代Java
关注时代Java