/* * Copyright (c) 1997, 2022, 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. *
*/
// API level must be at least Windows Vista or Server 2008 to use InitOnceExecuteOnce
// No setuid programs under Windows. bool os::have_special_privileges() { returnfalse;
}
// 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(outputStream* st) { 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);
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
}
}
}
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
#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.
// 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;
}
if (committed_start == NULL) {
assert(committed_size == 0, "Sanity"); returnfalse;
} 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)); returntrue;
}
}
#ifdef USE_VECTORED_EXCEPTION_HANDLING // Any exception is caught by the Vectored Exception Handler, so VM can // generate error dump when an exception occurred in non-Java thread // (e.g. VM thread).
thread->call_run(); #else // 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.
} #endif
// Note: at this point the thread object may already have deleted itself. // Do not dereference it from here on out.
// 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(); 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);
// Helper function to trace _beginthreadex attributes, // similar to os::Posix::describe_pthread_attr() staticchar* 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 / K);
}
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(); if (osthread == NULL) { returnfalse;
}
// Initial state is ALLOCATED but not INITIALIZED
osthread->set_state(ALLOCATED);
// 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; returnfalse;
}
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::gc_thread: case os::asynclog_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.
ResourceMark rm; char buf[64]; if (thread_handle != NULL) {
log_info(os, thread)("Thread \"%s\" started (tid: %u, attributes: %s)",
thread->name(), thread_id,
describe_beginthreadex_attributes(buf, sizeof(buf), stack_size, initflag));
} else {
log_warning(os, thread)("Failed to start thread \"%s\" - _beginthreadex failed (%s) for attributes: %s.",
thread->name(), 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; returnfalse;
}
// Store info on the Win32 thread into the OSThread
osthread->set_thread_handle(thread_handle);
osthread->set_thread_id(thread_id);
// Thread state now 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 returntrue;
}
// 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");
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);
bool os::has_allocatable_memory_limit(size_t* limit) {
MEMORYSTATUSEX ms;
ms.dwLength = sizeof(ms);
GlobalMemoryStatusEx(&ms); #ifdef _LP64
*limit = (size_t)ms.ullAvailVirtual; returntrue; #else // Limit to 1400m because of the 2gb address space wall
*limit = MIN2((size_t)1400*M, (size_t)ms.ullAvailVirtual); returntrue; #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;
}
}
if (_SetThreadDescription != NULL) { // SetThreadDescription takes a PCWSTR but we have conversion routines that produce // LPWSTR. The only difference is that PCWSTR is a pointer to const WCHAR.
LPWSTR unicode_name;
errno_t err = convert_to_unicode(name, &unicode_name); if (err == ERROR_SUCCESS) {
HANDLE current = GetCurrentThread();
HRESULT hr = _SetThreadDescription(current, unicode_name); if (FAILED(hr)) {
log_debug(os, thread)("set_native_thread_name: SetThreadDescription failed - falling back to debugger method");
FREE_C_HEAP_ARRAY(WCHAR, unicode_name);
} else {
log_trace(os, thread)("set_native_thread_name: SetThreadDescription succeeded - new name: %s", name);
#ifdef ASSERT // For verification purposes in a debug build we read the thread name back and check it.
PWSTR thread_name;
HRESULT hr2 = _GetThreadDescription(current, &thread_name); if (FAILED(hr2)) {
log_debug(os, thread)("set_native_thread_name: GetThreadDescription failed!");
} else { int res = CompareStringW(LOCALE_USER_DEFAULT,
0, // no special comparison rules
unicode_name,
-1, // null-terminated
thread_name,
-1 // null-terminated
);
assert(res == CSTR_EQUAL, "Name strings were not the same - set: %ls, but read: %ls", unicode_name, thread_name);
LocalFree(thread_name);
} #endif
FREE_C_HEAP_ARRAY(WCHAR, unicode_name); return;
}
} else {
log_debug(os, thread)("set_native_thread_name: convert_to_unicode failed - falling back to debugger method");
}
}
// 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()) {
log_debug(os, thread)("set_native_thread_name: no debugger present so unable to set thread name"); 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;
// 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; staticint _has_calculated_offset = 0;
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());
}
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;
} elseif (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
}
// 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) { constchar* 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);
}
// 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 '\\'.
// 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;
}
// This must be hard coded because it's the system's temporary // directory not the java application's temp directory, ala java.io.tmpdir. constchar* os::get_temp_directory() { staticchar 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> constchar* 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. // staticbool _addr_in_ntdll(address addr) {
HMODULE hmod;
MODULEINFO minfo;
hmod = GetModuleHandle("NTDLL.DLL"); if (hmod == NULL) returnfalse; if (!GetModuleInformation(GetCurrentProcess(), hmod,
&minfo, sizeof(MODULEINFO))) { returnfalse;
}
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.
buf[0] = '\0'; if (offset) *offset = -1; returnfalse;
}
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");
// save the start and end address of jvm.dll into param[0] and param[1] staticint _locate_jvm_dll(constchar* mod_fname, address base_addr,
address top_address, void * param) { if (!param) return -1;
// 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(constchar *name, char *ebuf, int ebuflen) {
log_info(os)("attempting shared library load of %s", name);
void * result = LoadLibrary(name); if (result != NULL) {
Events::log_dll_message(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_dll_message(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);
// 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) !=
(::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) != (::read(fd, (void*)&lib_arch, sizeof(lib_arch))))
);
staticconst arch_t arch_array[] = {
{IMAGE_FILE_MACHINE_I386, (char*)"IA 32"},
{IMAGE_FILE_MACHINE_AMD64, (char*)"AMD 64"},
{IMAGE_FILE_MACHINE_ARM64, (char*)"ARM 64"}
}; #if (defined _M_ARM64) staticconst uint16_t running_arch = IMAGE_FILE_MACHINE_ARM64; #elif (defined _M_AMD64) staticconst uint16_t running_arch = IMAGE_FILE_MACHINE_AMD64; #elif (defined _M_IX86) staticconst 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 or _M_ARM64 #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 (unsignedint 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);
}
// 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';
}
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, constchar* fmt, va_list args) { // Starting with Visual Studio 2015, vsnprint is C99 compliant.
ALLOW_C_FUNCTION(::vsnprintf, 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;
}
staticinline time_t get_mtime(constchar* 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;
}
// 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) { if (build_number >= 22000) {
st->print("11");
} else {
st->print("10");
}
} else { // distinguish Windows Server by build number // - 2016 GA 10/2016 build: 14393 // - 2019 GA 11/2018 build: 17763 // - 2022 GA 08/2021 build: 20348 if (build_number > 20347) {
st->print("Server 2022");
} elseif (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) ||
(si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_ARM64)) {
st->print(" , 64 bit");
}
// 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);
// on 32bit Total/AvailVirtual are interesting (show us how close we get to 2-4 GB per process borders) #ifdefined(_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(constvoid* siginfo) { // TODO: Is this possible? returnfalse;
}
// 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 ((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 constchar* 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 signal_handler_t sigbreakHandler = NULL;
staticvoid UserHandler(int sig) {
os::signal_notify(sig); // We need to reinstate the signal handler each time...
os::win32::install_signal_handler(sig, UserHandler);
}
// Used mainly by JVM_RegisterSignal to install a signal handler, // but also to install the VM's BREAK_HANDLER. However, due to // the way Windows signals work we also have to reinstall each // handler at the end of its own execution. // The allowed set of signals is restricted by the caller. // The incoming handler is one of: // - psuedo-handler: SIG_IGN or SIG_DFL // - VM defined signal handling function of type signal_handler_t // - unknown signal handling function which we expect* is also // of type signal_handler_t // // * win32 defines a two-arg signal handling function for use solely with // SIGFPE. As we don't allow that to be set via the Java API we know we // only have the single arg version. // Returns the currently installed handler. void* os::win32::install_signal_handler(int sig, signal_handler_t handler) { if ((sig == SIGBREAK) && (!ReduceSignalUsage)) { void* oldHandler = CAST_FROM_FN_PTR(void*, sigbreakHandler);
sigbreakHandler = handler; return oldHandler;
} else { return ::signal(sig, handler);
}
}
// 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. // staticBOOL 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();
}
::raise(SIGINT); returnTRUE; break; case CTRL_BREAK_EVENT: if (sigbreakHandler != NULL) {
(*sigbreakHandler)(SIGBREAK);
} returnTRUE; 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) { returnFALSE;
}
}
} case CTRL_CLOSE_EVENT: case CTRL_SHUTDOWN_EVENT:
::raise(SIGTERM); returnTRUE; break; default: break;
} returnFALSE;
}
// 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 staticvolatile jint pending_signals[NSIG+1] = { 0 }; static Semaphore* sig_sem = NULL;
staticvoid 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);
// Initialize sigbreakHandler. // The actual work for handling CTRL-BREAK is performed by the Signal // Dispatcher thread, which is created and started at a much later point, // see os::initialize_jdk_signal_support(). Any CTRL-BREAK received // before the Signal Dispatcher thread is started is queued up via the // pending_signals[SIGBREAK] counter, and will be processed by the // Signal Dispatcher thread in a delayed fashion.
os::win32::install_signal_handler(SIGBREAK, UserHandler);
}
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");
}
}
staticint 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;
}
}
sig_sem->wait_with_safepoint_check(JavaThread::current());
}
ShouldNotReachHere(); return 0; // Satisfy compiler
}
int os::signal_wait() { return check_pending_signals();
}
// Save pc in thread if (thread != nullptr && thread->is_Java_thread()) {
JavaThread::cast(thread)->set_saved_exception_pc((address)(DWORD_PTR)exceptionInfo->ContextRecord->PC_NAME);
}
// Set pc to handler
exceptionInfo->ContextRecord->PC_NAME = (DWORD64)handler;
// 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).
// 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".
constchar* 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) #ifdefined(_M_ARM64)
PCONTEXT ctx = exceptionInfo->ContextRecord;
address pc = (address)ctx->Sp;
assert(pc[0] == 0x83, "not an sdiv opcode"); //Fixme did i get the right opcode?
assert(ctx->X4 == min_jint, "unexpected idiv exception"); // set correct result values and continue after idiv instruction
ctx->Pc = (uint64_t)pc + 4; // idiv reg, reg, reg is 4 bytes
ctx->X4 = (uint64_t)min_jint; // result
ctx->X5 = (uint64_t)0; // remainder // Continue the execution #elifdefined(_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;
}
#ifdefined(_M_AMD64) || defined(_M_IX86) //----------------------------------------------------------------------------- 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::x86::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::x86::addr_mxcsr_std() // because in Win64 mxcsr is not saved there if (MxCsr != ctx->MxCsr) {
ctx->MxCsr = MxCsr; return EXCEPTION_CONTINUE_EXECUTION;
} #endif// !_WIN64
// If UseOSErrorReporting, this will return here and save the error file // somewhere where we can find it in the minidump.
}
//-----------------------------------------------------------------------------
JNIEXPORT LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) { if (InterceptOSException) return EXCEPTION_CONTINUE_SEARCH;
PEXCEPTION_RECORD exception_record = exceptionInfo->ExceptionRecord;
DWORD exception_code = exception_record->ExceptionCode; #ifdefined(_M_ARM64)
address pc = (address) exceptionInfo->ContextRecord->Pc; #elifdefined(_M_AMD64)
address pc = (address) exceptionInfo->ContextRecord->Rip; #else
address pc = (address) exceptionInfo->ContextRecord->Eip; #endif
Thread* t = Thread::current_or_null_safe();
#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) { int exception_subcode = (int) exception_record->ExceptionInformation[0];
address addr = (address) exception_record->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);
// 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);
// 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"); #if !defined(USE_VECTORED_EXCEPTION_HANDLING)
report_error(t, exception_code, addr, exception_record,
exceptionInfo->ContextRecord); #endif return EXCEPTION_CONTINUE_SEARCH;
}
} #endif// _WIN64
#ifdefined(_M_AMD64) || defined(_M_IX86) 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());
} #endif
// Handle potential stack overflows up front. if (exception_code == EXCEPTION_STACK_OVERFLOW) {
StackOverflow* overflow_state = thread->stack_overflow_state(); if (overflow_state->stack_guards_enabled()) { if (in_java) {
frame fr; 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(!in_vm, "Undersized StackShadowPages");
overflow_state->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.
overflow_state->disable_stack_red_zone();
tty->print_raw_cr("An unrecoverable stack overflow has occurred."); #if !defined(USE_VECTORED_EXCEPTION_HANDLING)
report_error(t, exception_code, pc, exception_record,
exceptionInfo->ContextRecord); #endif return EXCEPTION_CONTINUE_SEARCH;
}
} elseif (exception_code == EXCEPTION_ACCESS_VIOLATION) { if (in_java) { // Either stack overflow or null pointer exception.
address addr = (address) exception_record->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 (SafepointMechanism::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 if (thread->is_in_usable_stack(addr)) {
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;
} #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, exception_record,
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.
address slowcase_pc = JNI_FastGetField::find_slowcase_pc(pc); if (slowcase_pc != (address)-1) { return Handle_Exception(exceptionInfo, slowcase_pc);
} #endif
#ifdefined(USE_VECTORED_EXCEPTION_HANDLING) LONG WINAPI topLevelVectoredExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord; #ifdefined(_M_ARM64)
address pc = (address) exceptionInfo->ContextRecord->Pc; #elifdefined(_M_AMD64)
address pc = (address) exceptionInfo->ContextRecord->Rip; #else
address pc = (address) exceptionInfo->ContextRecord->Eip; #endif
// Fast path for code part of the code cache if (CodeCache::low_bound() <= pc && pc < CodeCache::high_bound()) { return topLevelExceptionFilter(exceptionInfo);
}
// If the exception occurred in the codeCache, pass control // to our normal exception handler.
CodeBlob* cb = CodeCache::find_blob(pc); if (cb != NULL) { return topLevelExceptionFilter(exceptionInfo);
}
return EXCEPTION_CONTINUE_SEARCH;
} #endif
#ifdefined(USE_VECTORED_EXCEPTION_HANDLING) LONG WINAPI topLevelUnhandledExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) { if (InterceptOSException) gotoexit;
DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode; #ifdefined(_M_ARM64)
address pc = (address)exceptionInfo->ContextRecord->Pc; #elifdefined(_M_AMD64)
address pc = (address) exceptionInfo->ContextRecord->Rip; #else
address pc = (address) exceptionInfo->ContextRecord->Eip; #endif
Thread* t = Thread::current_or_null_safe();
#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;
}
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
// 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.
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)) returnfalse;
ULONG highest_node_number; if (!GetNumaHighestNodeNumber(&highest_node_number)) returnfalse;
free_node_list();
_numa_used_node_list = NEW_C_HEAP_ARRAY(int, highest_node_number + 1, mtInternal); for (unsignedint i = 0; i <= highest_node_number; i++) {
ULONGLONG proc_mask_numa_node; if (!GetNumaNodeProcessorMask(i, &proc_mask_numa_node)) returnfalse; 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);
}
// print a warning if UseNUMAInterleaving flag is specified on command line bool warn_on_failure = !FLAG_IS_DEFAULT(UseNUMAInterleaving);
#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()) {
WARN("Process does not cover multiple NUMA nodes.");
WARN("...Ignoring UseNUMAInterleaving flag."); returnfalse;
}
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));
}
}
#undef WARN
returntrue;
}
// 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 staticchar* 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
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;
}
static size_t large_page_init_decide_size() { // 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);
#define WARN(msg) if (warn_on_failure) { warning(msg); }
if (!request_lock_memory_privilege()) {
WARN("JVM cannot use large page memory because it does not have enough privilege to lock pages in memory."); return 0;
}
size_t size = GetLargePageMinimum(); if (size == 0) {
WARN("Large page is not supported by the processor."); return 0;
}
#ifdefined(IA32) || defined(AMD64) if (size > 4*M || LargePageSizeInBytes > 4*M) {
WARN("JVM cannot use large pages bigger than 4mb."); return 0;
} #endif
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;
}
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"));
}
// 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. staticchar* map_or_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");
// Attempt to map, into the just vacated space, the slightly smaller aligned area. // Which may fail, hence the loop.
aligned_base = file_desc != -1 ? os::attempt_map_memory_to_file_at(aligned_base, size, file_desc) :
os::attempt_reserve_memory_at(aligned_base, size);
}
assert(aligned_base != NULL, "Did not manage to re-map after %d attempts?", max_attempts);
// 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(char* addr, size_t bytes, bool exec) {
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;
}
char* os::pd_attempt_map_memory_to_file_at(char* requested_addr, size_t bytes, int file_desc) {
assert(file_desc >= 0, "file_desc is not valid"); return map_memory_to_file(requested_addr, bytes, file_desc);
}
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. returnfalse;
}
char * p_buf = allocate_pages_individually(size, req_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;
}
staticchar* reserve_large_pages_single_range(size_t size, char* req_addr, bool exec) {
log_debug(pagesize)("Reserving large pages in a single large chunk.");
staticchar* reserve_large_pages(size_t size, char* req_addr, bool exec) { // 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) { return reserve_large_pages_individually(size, req_addr, exec);
} return reserve_large_pages_single_range(size, req_addr, exec);
}
staticchar* find_aligned_address(size_t size, size_t alignment) { // Temporary reserve memory large enough to ensure we can get the requested // alignment and still fit the reservation. char* addr = (char*) virtualAlloc(NULL, size + alignment, MEM_RESERVE, PAGE_NOACCESS); // Align the address to the requested alignment. char* aligned_addr = align_up(addr, alignment); // Free the temporary reservation.
virtualFree(addr, 0, MEM_RELEASE);
return aligned_addr;
}
staticchar* reserve_large_pages_aligned(size_t size, size_t alignment, bool exec) {
log_debug(pagesize)("Reserving large pages at an aligned address, alignment=" SIZE_FORMAT "%s",
byte_size_in_exact_unit(alignment), exact_unit_for_byte_size(alignment));
// Will try to find a suitable address at most 20 times. The reason we need to try // multiple times is that between finding the aligned address and trying to commit // the large pages another thread might have reserved an overlapping region. constint attempts_limit = 20; for (int attempts = 0; attempts < attempts_limit; attempts++) { // Find aligned address. char* aligned_address = find_aligned_address(size, alignment);
// Try to do the large page reservation using the aligned address.
aligned_address = reserve_large_pages(size, aligned_address, exec); if (aligned_address != NULL) { // Reservation at the aligned address succeeded.
guarantee(is_aligned(aligned_address, alignment), "Must be aligned"); return aligned_address;
}
}
log_debug(pagesize)("Failed reserving large pages at aligned address"); return NULL;
}
char* os::pd_reserve_memory_special(size_t bytes, size_t alignment, size_t page_size, char* addr, bool exec) {
assert(UseLargePages, "only for large pages");
assert(page_size == os::large_page_size(), "Currently only support one large page size on Windows");
assert(is_aligned(addr, alignment), "Must be");
assert(is_aligned(addr, page_size), "Must be");
if (!is_aligned(bytes, page_size)) { // Fallback to small pages, Windows does not support mixed mappings. return NULL;
}
// The requested alignment can be larger than the page size, for example with G1 // the alignment is bound to the heap region size. So this reservation needs to // ensure that the requested alignment is met. When there is a requested address // this solves it self, since it must be properly aligned already. if (addr == NULL && alignment > page_size) { return reserve_large_pages_aligned(bytes, alignment, exec);
}
// No additional requirements, just reserve the large pages. return reserve_large_pages(bytes, addr, exec);
}
bool os::pd_commit_memory(char* addr, size_t bytes, bool exec) { if (bytes == 0) { // Don't bother the OS with noops. returntrue;
}
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);) returnfalse;
} 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);) returnfalse;
}
} returntrue;
} 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);) returnfalse;
} 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);) returnfalse;
}
}
bytes_remaining -= bytes_to_rq;
next_alloc_addr += bytes_to_rq;
}
} // if we made it this far, return true returntrue;
}
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,
size_t alignment_hint, bool exec, constchar* 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, bool exec) { if (bytes == 0) { // Don't bother the OS with noops. returntrue;
}
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) == TRUE);
}
bool os::pd_release_memory(char* addr, size_t bytes) { // Given a range we are to release, we require a mapping to start at the beginning of that range; // if NUMA or LP we allow the range to contain multiple mappings, which have to cover the range // completely; otherwise the range must match an OS mapping exactly.
address start = (address)addr;
address end = start + bytes;
os::win32::mapping_info_t mi; constbool multiple_mappings_allowed = UseLargePagesIndividualAllocation || UseNUMAInterleaving;
address p = start; bool first_mapping = true;
do { // Find mapping and check it constchar* err = NULL; if (!os::win32::find_mapping(p, &mi)) {
err = "no mapping found";
} else { if (first_mapping) { if (mi.base != start) {
err = "base address mismatch";
} if (multiple_mappings_allowed ? (mi.size > bytes) : (mi.size != bytes)) {
err = "size mismatch";
}
} else {
assert(p == mi.base && mi.size > 0, "Sanity"); if (mi.base + mi.size > end) {
err = "mapping overlaps end";
} if (mi.size == 0) {
err = "zero length mapping?"; // Should never happen; just to prevent endlessly looping in release.
}
}
} // Handle mapping error. We assert in debug, unconditionally print a warning in release. if (err != NULL) {
log_warning(os)("bad release: [" PTR_FORMAT "-" PTR_FORMAT "): %s", p2i(start), p2i(end), err); #ifdef ASSERT
os::print_memory_mappings((char*)start, bytes, tty);
assert(false, "bad release: [" PTR_FORMAT "-" PTR_FORMAT "): %s", p2i(start), p2i(end), err); #endif returnfalse;
} // Free this range if (virtualFree(p, 0, MEM_RELEASE) == FALSE) { returnfalse;
}
first_mapping = false;
p = mi.base + mi.size;
} while (p < end);
// 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) { returnfalse;
}
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) { returnfalse;
}
// Set protections specified bool os::protect_memory(char* addr, size_t bytes, ProtType prot, bool is_committed) { unsignedint 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;
}
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). #ifdef _M_ARM64 // AArch64 has a maximum addressable space of 48-bits return (char*)((1ull << 48) - 1); #else return (char*)-1; #endif
}
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
}
}
typedefBOOL (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::current_process_id() { return (_initial_pid ? _initial_pid : _getpid());
}
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;
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;
// 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));
}
_is_windows_server = IsWindowsServer();
initialize_performance_counter();
}
HINSTANCE os::win32::load_Windows_dll(constchar* 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;
}
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]; staticint handle_count = 0;
// 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__);
} elseif (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().
}
} elseif (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);
} elseif (what == EPT_PROCESS) {
ALLOW_C_FUNCTION(::exit, ::exit(exit_code);)
} else { // EPT_PROCESS_DIE
ALLOW_C_FUNCTION(::_exit, ::_exit(exit_code);)
}
// 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" { staticvoid perfMemory_exit_helper() {
perfMemory_exit();
}
}
static jint initSock();
// Minimum usable stack sizes required to get to user code. Space for // HotSpot guard pages is added later.
size_t os::_compiler_thread_min_stack_allowed = 48 * K;
size_t os::_java_thread_min_stack_allowed = 40 * K; #ifdef _LP64
size_t os::_vm_internal_thread_min_stack_allowed = 64 * K; #else
size_t os::_vm_internal_thread_min_stack_allowed = (48 DEBUG_ONLY(+ 4)) * K; #endif// _LP64
// If stack_commit_size is 0, windows will reserve the default size, // but only commit a small portion of it. This stack size is the size of this // current thread but is larger than we need for Java threads. // If -Xss is given to the launcher, it will pick 64K as default stack size and pass that.
size_t os::_os_min_stack_allowed = 64 * K;
// 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();)
// Check and sets minimum stack sizes against command line options if (set_minimum_stack_sizes() == JNI_ERR) { return JNI_ERR;
}
// 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();
UseNUMA = false; // We don't fully support this yet
if (UseNUMAInterleaving || (UseNUMA && FLAG_IS_DEFAULT(UseNUMAInterleaving))) { if (!numa_interleaving_init()) {
FLAG_SET_ERGO(UseNUMAInterleaving, false);
} elseif (!UseNUMAInterleaving) { // When NUMA requested, not-NUMA-aware allocations default to interleaving.
FLAG_SET_ERGO(UseNUMAInterleaving, true);
}
}
if (initSock() != JNI_OK) { return JNI_ERR;
}
SymbolEngine::recalc_search_path();
// Initialize data for jdk.internal.misc.Signal, and install CTRL-C and // CTRL-BREAK handlers. if (!ReduceSignalUsage) {
jdk_misc_signal_init();
}
// Lookup SetThreadDescription - the docs state we must use runtime-linking of // kernelbase.dll, so that is what we do.
HINSTANCE _kernelbase = LoadLibrary(TEXT("kernelbase.dll")); if (_kernelbase != NULL) {
_SetThreadDescription = reinterpret_cast<SetThreadDescriptionFnPtr>(
GetProcAddress(_kernelbase, "SetThreadDescription")); #ifdef ASSERT
_GetThreadDescription = reinterpret_cast<GetThreadDescriptionFnPtr>(
GetProcAddress(_kernelbase, "GetThreadDescription")); #endif
}
log_info(os, thread)("The SetThreadDescription API is%s available.", _SetThreadDescription == NULL ? " not" : "");
return JNI_OK;
}
// 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;
}
int result = MultiByteToWideChar(CP_ACP,
MB_ERR_INVALID_CHARS,
char_path, -1,
*unicode_path, unicode_path_len);
assert(result == unicode_path_len, "length already checked above");
return ERROR_SUCCESS;
}
static errno_t get_full_path(LPCWSTR unicode_path, LPWSTR* full_path) { // Get required buffer size to convert to full path. The return // value INCLUDES the terminating null character.
DWORD full_path_len = GetFullPathNameW(unicode_path, 0, NULL, NULL); if (full_path_len == 0) { return EINVAL;
}
// When the buffer has sufficient size, the return value EXCLUDES the // terminating null character
DWORD result = GetFullPathNameW(unicode_path, full_path_len, *full_path, NULL);
assert(result <= full_path_len, "length already checked above");
// 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 size of space, in wchar_t, the function will additionally add to // the allocation of return buffer (such that the size of the returned buffer is at least // wcslen(buf) + 1 + additional_space). staticwchar_t* wide_abs_unc_path(charconst* path, errno_t & err, int additional_space = 0) { if ((path == NULL) || (path[0] == '\0')) {
err = ENOENT; return NULL;
}
// Need to allocate at least room for 3 characters, since os::native_path transforms C: to C:.
size_t buf_len = 1 + MAX2((size_t)3, strlen(path)); char* buf = NEW_C_HEAP_ARRAY(char, buf_len, mtInternal);
strncpy(buf, path, buf_len);
os::native_path(buf);
// 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);
}
// 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::thread_cpu_time(Thread* thread, bool user_sys_cpu_time) { // This code is copy from classic VM -> hpi::sysThreadCPUTime // If this function changes, os::is_thread_cpu_time_supported() should too
FILETIME CreationTime;
FILETIME ExitTime;
FILETIME KernelTime;
FILETIME UserTime;
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
}
// Windows doesn'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(constchar *path, int oflag, int mode) {
errno_t err; wchar_t* wide_path = wide_abs_unc_path(path, err);
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);
}
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) {
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;
}
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;
}
}
// Remap a block of memory. char* os::pd_remap_memory(int fd, constchar* 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.
// 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' flags 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) { returnfalse;
} returntrue;
}
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. //
int PlatformEvent::park(jlong Millis) { // Transitions for _Event: // -1 => -1 : illegal // 1 => 0 : pass - return immediately // 0 => -1 : block; then set _Event to 0 before returning
// CONSIDER: defer assigning a CreateEvent() handle to the Event until // the initial park() operation. // Consider: use atomic decrement instead of CAS-loop
int v; for (;;) {
v = _Event; if (Atomic::cmpxchg(&_Event, v, v-1) == v) break;
}
guarantee((v == 0) || (v == 1), "invariant"); if (v != 0) return OS_OK;
// Do this the hard way by blocking ... // TODO: consider a brief spin here, gated on the success of recent // spin attempts by this thread. // // We decompose long timeouts into series of shorter timed waits. // Evidently large timo values passed in WaitForSingleObject() are problematic on some // versions of Windows. See EventWait() for details. This may be superstition. Or not. // We trust the WAIT_TIMEOUT indication and don't track the elapsed wait time // with os::javaTimeNanos(). Furthermore, we assume that spurious returns from // ::WaitForSingleObject() caused by latent ::setEvent() operations will tend // to happen early in the wait interval. Specifically, after a spurious wakeup (rv == // WAIT_OBJECT_0 but _Event is still < 0) we don't bother to recompute Millis to compensate // for the already waited time. This policy does not admit any new outcomes. // In the future, however, we might want to track the accumulated wait time and // adjust Millis accordingly if we encounter a spurious wakeup.
constint MAXTIMEOUT = 0x10000000;
DWORD rv = WAIT_TIMEOUT; while (_Event < 0 && Millis > 0) {
DWORD prd = Millis; // set prd = MAX (Millis, MAXTIMEOUT) if (Millis > MAXTIMEOUT) {
prd = MAXTIMEOUT;
}
HighResolutionInterval *phri = NULL; if (!ForceTimeHighResolution) {
phri = new HighResolutionInterval(prd);
}
rv = ::WaitForSingleObject(_ParkHandle, prd);
assert(rv == WAIT_OBJECT_0 || rv == WAIT_TIMEOUT, "WaitForSingleObject failed"); if (rv == WAIT_TIMEOUT) {
Millis -= prd;
} delete phri; // if it is NULL, harmless
}
v = _Event;
_Event = 0; // see comment at end of PlatformEvent::park() below:
OrderAccess::fence(); // If we encounter a nearly simultaneous timeout expiry and unpark() // we return OS_OK indicating we awoke via unpark(). // Implementor's license -- returning OS_TIMEOUT would be equally valid, however. return (v >= 0) ? OS_OK : OS_TIMEOUT;
}
void PlatformEvent::park() { // Transitions for _Event: // -1 => -1 : illegal // 1 => 0 : pass - return immediately // 0 => -1 : block; then set _Event to 0 before returning
guarantee(_ParkHandle != NULL, "Invariant"); // Invariant: Only the thread associated with the Event/PlatformEvent // may call park(). // Consider: use atomic decrement instead of CAS-loop int v; for (;;) {
v = _Event; if (Atomic::cmpxchg(&_Event, v, v-1) == v) break;
}
guarantee((v == 0) || (v == 1), "invariant"); if (v != 0) return;
// Do this the hard way by blocking ... // TODO: consider a brief spin here, gated on the success of recent // spin attempts by this thread. while (_Event < 0) {
DWORD rv = ::WaitForSingleObject(_ParkHandle, INFINITE);
assert(rv == WAIT_OBJECT_0, "WaitForSingleObject failed");
}
// Usually we'll find _Event == 0 at this point, but as // an optional optimization we clear it, just in case can // multiple unpark() operations drove _Event up to 1.
_Event = 0;
OrderAccess::fence();
guarantee(_Event >= 0, "invariant");
}
// Transitions for _Event: // 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. // See also: "Semaphores in Plan 9" by Mullender & Cox // // Note: Forcing a transition from "-1" to "1" on an unpark() means // that it will take two back-to-back park() calls for the owning // thread to block. This has the benefit of forcing a spurious return // from the first park() call after an unpark() call which will help // shake out uses of park() and unpark() without condition variables.
// The Windows implementation of Park is very straightforward: Basic // operations on Win32 Events turn out to have the right semantics to // use them directly.
void Parker::park(bool isAbsolute, jlong time) {
guarantee(_ParkHandle != NULL, "invariant"); // First, demultiplex/decode time arguments if (time < 0) { // don't wait return;
} elseif (time == 0 && !isAbsolute) {
time = INFINITE;
} elseif (isAbsolute) {
time -= os::javaTimeMillis(); // convert to relative time if (time <= 0) { // already elapsed return;
}
} else { // relative
time /= 1000000; // Must coarsen from nanos to millis if (time == 0) { // Wait for the minimal time unit if zero
time = 1;
}
}
JavaThread* thread = JavaThread::current();
// Don't wait if interrupted or already triggered if (thread->is_interrupted(false) ||
WaitForSingleObject(_ParkHandle, 0) == WAIT_OBJECT_0) {
ResetEvent(_ParkHandle); return;
} else {
ThreadBlockInVM tbivm(thread);
OSThreadWaitState osts(thread->osthread(), false/* not Object.wait() */);
// Must already be locked int PlatformMonitor::wait(jlong millis) {
assert(millis >= 0, "negative timeout"); int ret = OS_TIMEOUT; int status = SleepConditionVariableCS(&_cond, &_mutex,
millis == 0 ? INFINITE : millis); if (status != 0) {
ret = OS_OK;
} #ifndef PRODUCT else {
DWORD err = GetLastError();
assert(err == ERROR_TIMEOUT, "SleepConditionVariableCS: %ld:", err);
} #endif return ret;
}
// Run the specified command in a separate process. Return its exit value, // or -1 on failure (e.g. can't create a new process). int os::fork_and_exec(constchar* cmd) {
STARTUPINFO si;
PROCESS_INFORMATION pi;
DWORD exit_code;
// get context capable handle for thread
get_thread_handle_for_extended_context(&h, _thread->osthread()->thread_id());
// sanity if (h == NULL || h == INVALID_HANDLE_VALUE) { return;
}
// suspend the thread if (do_suspend(&h)) {
ctxt.ContextFlags = sampling_context_flags; // get thread context
GetThreadContext(h, &ctxt);
SuspendedThreadTaskContext context(_thread, &ctxt); // pass context to Thread Sampling impl
do_task(context); // resume thread
do_resume(&h);
}
// close handle
CloseHandle(h);
}
bool os::start_debugging(char *buf, int buflen) { int len = (int)strlen(buf); char *p = &buf[len];
jio_snprintf(p, buflen-len, "\n\n" "Do you want to debug the problem?\n\n" "To debug, attach Visual Studio to process %d; then switch to thread 0x%x\n" "Select 'Yes' to launch Visual Studio automatically (PATH must include msdev)\n" "Otherwise, select 'No' to abort...",
os::current_process_id(), os::current_thread_id());
if (yes) { // os::breakpoint() calls DebugBreak(), which causes a breakpoint // exception. If VM is running inside a debugger, the debugger will // catch the exception. Otherwise, the breakpoint exception will reach // the default windows exception handler, which can spawn a debugger and // automatically attach to the dying VM.
os::breakpoint();
yes = false;
} return yes;
}
// Builds a platform dependent Agent_OnLoad_<lib_name> function name // which is used to find statically linked in agents. // Additionally for windows, takes into account __stdcall names. // Parameters: // sym_name: Symbol in library we are looking for // lib_name: Name of library to look in, NULL for shared libs. // is_absolute_path == true if lib_name is absolute path to agent // such as "C:/a/b/L.dll" // == false if only the base name of the library is passed in // such as "L" char* os::build_agent_function_name(constchar *sym_name, constchar *lib_name, bool is_absolute_path) { char *agent_entry_name;
size_t len;
size_t name_len;
size_t prefix_len = strlen(JNI_LIB_PREFIX);
size_t suffix_len = strlen(JNI_LIB_SUFFIX); constchar *start;
if (lib_name != NULL) {
len = name_len = strlen(lib_name); if (is_absolute_path) { // Need to strip path, prefix and suffix if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
lib_name = ++start;
} else { // Need to check for drive prefix if ((start = strchr(lib_name, ':')) != NULL) {
lib_name = ++start;
}
} if (len <= (prefix_len + suffix_len)) { return NULL;
}
lib_name += prefix_len;
name_len = strlen(lib_name) - suffix_len;
}
}
len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread); if (agent_entry_name == NULL) { return NULL;
} if (lib_name != NULL) { constchar *p = strrchr(sym_name, '@'); if (p != NULL && p != sym_name) { // sym_name == _Agent_OnLoad@XX
strncpy(agent_entry_name, sym_name, (p - sym_name));
agent_entry_name[(p-sym_name)] = '\0'; // agent_entry_name == _Agent_OnLoad
strcat(agent_entry_name, "_");
strncat(agent_entry_name, lib_name, name_len);
strcat(agent_entry_name, p); // agent_entry_name == _Agent_OnLoad_lib_name@XX
} else {
strcpy(agent_entry_name, sym_name);
strcat(agent_entry_name, "_");
strncat(agent_entry_name, lib_name, name_len);
}
} else {
strcpy(agent_entry_name, sym_name);
} return agent_entry_name;
}
/* All the defined signal names for Windows.
NOTE that not all of these names are accepted by FindSignal!
For various reasons some of these may be rejected at runtime.
Here are the names currently accepted by a user of sun.misc.Signal with 1.4.1 (ignoring potential interaction with use of chaining, etc):
(LIST TBD)
*/ int os::get_signal_number(constchar* name) { staticconststruct { constchar* name; int number;
} siglabels [] = // derived from version 6.0 VC98/include/signal.h
{"ABRT", SIGABRT, // abnormal termination triggered by abort cl "FPE", SIGFPE, // floating point exception "SEGV", SIGSEGV, // segment violation "INT", SIGINT, // interrupt "TERM", SIGTERM, // software term signal from kill "BREAK", SIGBREAK, // Ctrl-Break sequence "ILL", SIGILL}; // illegal instruction for (unsigned i = 0; i < ARRAY_SIZE(siglabels); ++i) { if (strcmp(name, siglabels[i].name) == 0) { return siglabels[i].number;
}
} return -1;
}
// Fast current thread access
int os::win32::_thread_ptr_offset = 0;
staticvoid call_wrapper_dummy() {}
// We need to call the os_exception_wrapper once so that it sets // up the offset from FS of the thread pointer. void os::win32::initialize_thread_ptr_offset() {
os::os_exception_wrapper((java_call_t)call_wrapper_dummy,
NULL, methodHandle(), NULL, NULL);
}
// Given a pointer pointing into an allocation (an area allocated with VirtualAlloc), // return information about that allocation. bool os::win32::find_mapping(address addr, mapping_info_t* mi) { // Query at addr to find allocation base; then, starting at allocation base, // query all regions, until we either find the next allocation or a free area.
ZeroMemory(mi, sizeof(mapping_info_t));
MEMORY_BASIC_INFORMATION minfo;
address allocation_base = NULL;
address allocation_end = NULL; bool rc = false; if (checkedVirtualQuery(addr, &minfo)) { if (minfo.State != MEM_FREE) {
allocation_base = (address)minfo.AllocationBase;
allocation_end = allocation_base; // Iterate through all regions in this allocation to find its end. While we are here, also count things. for (;;) { bool rc = checkedVirtualQuery(allocation_end, &minfo); if (rc == false || // VirtualQuery error, end of allocation?
minfo.State == MEM_FREE || // end of allocation, free memory follows
(address)minfo.AllocationBase != allocation_base) // end of allocation, a new one starts
{ break;
} const size_t region_size = minfo.RegionSize;
mi->regions ++; if (minfo.State == MEM_COMMIT) {
mi->committed_size += minfo.RegionSize;
}
allocation_end += region_size;
} if (allocation_base != NULL && allocation_end > allocation_base) {
mi->base = allocation_base;
mi->size = allocation_end - allocation_base;
rc = true;
}
}
} #ifdef ASSERT if (rc) {
assert(mi->size > 0 && mi->size >= mi->committed_size, "Sanity");
assert(addr >= mi->base && addr < mi->base + mi->size, "Sanity");
assert(mi->regions > 0, "Sanity");
} #endif return rc;
}
// Helper for print_one_mapping: print n words, both as hex and ascii. // Use Safefetch for all values. staticvoid print_snippet(constvoid* p, outputStream* st) { staticconstint num_words = LP64_ONLY(3) NOT_LP64(6); staticconstint num_bytes = num_words * sizeof(int);
intptr_t v[num_words]; constint errval = 0xDE210244; for (int i = 0; i < num_words; i++) {
v[i] = SafeFetchN((intptr_t*)p + i, errval); if (v[i] == errval &&
SafeFetchN((intptr_t*)p + i, ~errval) == ~errval) { return;
}
}
st->put('['); for (int i = 0; i < num_words; i++) {
st->print(INTPTR_FORMAT " ", v[i]);
} constchar* b = (char*)v;
st->put('\"'); for (int i = 0; i < num_bytes; i++) {
st->put(::isgraph(b[i]) ? b[i] : '.');
}
st->put('\"');
st->put(']');
}
// Helper function for print_memory_mappings: // Given a MEMORY_BASIC_INFORMATION, containing information about a non-free region: // print out all regions in that allocation. If any of those regions // fall outside the given range [start, end), indicate that in the output. // Return the pointer to the end of the allocation. static address print_one_mapping(MEMORY_BASIC_INFORMATION* minfo, address start, address end, outputStream* st) { // Print it like this: // // Base: <xxxxx>: [xxxx - xxxx], state=MEM_xxx, prot=x, type=MEM_xxx (region 1) // [xxxx - xxxx], state=MEM_xxx, prot=x, type=MEM_xxx (region 2)
assert(minfo->State != MEM_FREE, "Not inside an allocation.");
address allocation_base = (address)minfo->AllocationBase; #define IS_IN(p) (p >= start && p < end) bool first_line = true; bool is_dll = false; for(;;) { if (first_line) {
st->print("Base " PTR_FORMAT ": ", p2i(allocation_base));
} else {
st->print_raw(NOT_LP64 (" ")
LP64_ONLY(" "));
}
address region_start = (address)minfo->BaseAddress;
address region_end = region_start + minfo->RegionSize;
assert(region_end > region_start, "Sanity"); if (region_end <= start) {
st->print("<outside range> ");
} elseif (region_start >= end) {
st->print("<outside range> ");
} elseif (!IS_IN(region_start) || !IS_IN(region_end - 1)) {
st->print("<partly outside range> ");
}
st->print("[" PTR_FORMAT "-" PTR_FORMAT "), state=", p2i(region_start), p2i(region_end)); switch (minfo->State) { case MEM_COMMIT: st->print_raw("MEM_COMMIT "); break; case MEM_FREE: st->print_raw("MEM_FREE "); break; case MEM_RESERVE: st->print_raw("MEM_RESERVE"); break; default: st->print("%x?", (unsigned)minfo->State);
}
st->print(", prot=%3x, type=", (unsigned)minfo->Protect); switch (minfo->Type) { case MEM_IMAGE: st->print_raw("MEM_IMAGE "); break; case MEM_MAPPED: st->print_raw("MEM_MAPPED "); break; case MEM_PRIVATE: st->print_raw("MEM_PRIVATE"); break; default: st->print("%x?", (unsigned)minfo->State);
} // At the start of every allocation, print some more information about this mapping. // Notes: // - this could be beefed up a lot, similar to os::print_location // - for now we just query the allocation start point. This may be confusing for cases where // the kernel merges multiple mappings. if (first_line) { char buf[MAX_PATH]; if (os::dll_address_to_library_name(allocation_base, buf, sizeof(buf), nullptr)) {
st->print(", %s", buf);
is_dll = true;
}
} // If memory is accessible, and we do not know anything else about it, print a snippet if (!is_dll &&
minfo->State == MEM_COMMIT &&
!(minfo->Protect & PAGE_NOACCESS || minfo->Protect & PAGE_GUARD)) {
st->print_raw(", ");
print_snippet(region_start, st);
}
st->cr(); // Next region... bool rc = checkedVirtualQuery(region_end, minfo); if (rc == false || // VirtualQuery error, end of allocation?
(minfo->State == MEM_FREE) || // end of allocation, free memory follows
((address)minfo->AllocationBase != allocation_base) || // end of allocation, a new one starts
(region_end > end)) // end of range to print.
{ return region_end;
}
first_line = false;
} #undef IS_IN
ShouldNotReachHere(); return NULL;
}
void os::print_memory_mappings(char* addr, size_t bytes, outputStream* st) {
MEMORY_BASIC_INFORMATION minfo;
address start = (address)addr;
address end = start + bytes;
address p = start; if (p == nullptr) { // Lets skip the zero pages.
p += os::vm_allocation_granularity();
}
address p2 = p; // guard against wraparounds int fuse = 0;
while (p < end && p >= p2) {
p2 = p; // Probe for the next mapping. if (checkedVirtualQuery(p, &minfo)) { if (minfo.State != MEM_FREE) { // Found one. Print it out.
address p2 = print_one_mapping(&minfo, start, end, st);
assert(p2 > p, "Sanity");
p = p2;
} else { // Note: for free regions, most of MEMORY_BASIC_INFORMATION is undefined. // Only region dimensions are not: use those to jump to the end of // the free range.
address region_start = (address)minfo.BaseAddress;
address region_end = region_start + minfo.RegionSize;
assert(p >= region_start && p < region_end, "Sanity");
p = region_end;
}
} else { // MSDN doc on VirtualQuery is unclear about what it means if it returns an error. // In particular, whether querying an address outside any mappings would report // a MEM_FREE region or just return an error. From experiments, it seems to return // a MEM_FREE region for unmapped areas in valid address space and an error if we // are outside valid address space. // Here, we advance the probe pointer by alloc granularity. But if the range to print // is large, this may take a long time. Therefore lets stop right away if the address // is outside of what we know are valid addresses on Windows. Also, add a loop fuse. staticconst address end_virt = (address)(LP64_ONLY(0x7ffffffffffULL) NOT_LP64(3*G)); if (p >= end_virt) { break;
} else { // Advance probe pointer, but with a fuse to break long loops. if (fuse++ == 100000) { break;
}
p += os::vm_allocation_granularity();
}
}
}
}
void os::print_user_info(outputStream* st) { // not implemented yet
}
void os::print_active_locale(outputStream* st) { // not implemented yet
}
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