Quelle os_windows.cpp Sprache: C

/*
* 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 precompiled headers
#include "classfile/vmSymbols.hpp"
#include "code/codeCache.hpp"
#include "code/icBuffer.hpp"
#include "code/nativeInst.hpp"
#include "code/vtableStubs.hpp"
#include "compiler/compileBroker.hpp"
#include "compiler/disassembler.hpp"
#include "interpreter/interpreter.hpp"
#include "jvm.h"
#include "jvmtifiles/jvmti.h"
#include "logging/log.hpp"
#include "logging/logStream.hpp"
#include "memory/allocation.inline.hpp"
#include "oops/oop.inline.hpp"
#include "os_windows.inline.hpp"
#include "prims/jniFastGetField.hpp"
#include "prims/jvm_misc.hpp"
#include "runtime/arguments.hpp"
#include "runtime/atomic.hpp"
#include "runtime/globals.hpp"
#include "runtime/globals_extension.hpp"
#include "runtime/interfaceSupport.inline.hpp"
#include "runtime/java.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/javaThread.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/objectMonitor.hpp"
#include "runtime/orderAccess.hpp"
#include "runtime/osInfo.hpp"
#include "runtime/osThread.hpp"
#include "runtime/park.hpp"
#include "runtime/perfMemory.hpp"
#include "runtime/safefetch.hpp"
#include "runtime/safepointMechanism.hpp"
#include "runtime/semaphore.inline.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/statSampler.hpp"
#include "runtime/stubRoutines.hpp"
#include "runtime/threads.hpp"
#include "runtime/threadCritical.hpp"
#include "runtime/timer.hpp"
#include "runtime/vm_version.hpp"
#include "services/attachListener.hpp"
#include "services/memTracker.hpp"
#include "services/runtimeService.hpp"
#include "symbolengine.hpp"
#include "utilities/align.hpp"
#include "utilities/decoder.hpp"
#include "utilities/defaultStream.hpp"
#include "utilities/events.hpp"
#include "utilities/macros.hpp"
#include "utilities/vmError.hpp"
#include "windbghelp.hpp"

#ifdef _DEBUG
#include <crtdbg.h>
#endif

#include <windows.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/timeb.h>
#include <objidl.h>
#include <shlobj.h>

#include <malloc.h>
#include <signal.h>
#include <direct.h>
#include <errno.h>
#include <fcntl.h>
#include <io.h>
#include <process.h>              // For _beginthreadex(), _endthreadex()
#include <imagehlp.h>             // For os::dll_address_to_function_name
// for enumerating dll libraries
#include <vdmdbg.h>
#include <psapi.h>
#include <mmsystem.h>
#include <winsock2.h>
#include <versionhelpers.h>

// for timer info max values which include all bits
#define ALL_64_BITS CONST64(-1)

// For DLL loading/load error detection
// Values of PE COFF
#define IMAGE_FILE_PTR_TO_SIGNATURE 0x3c
#define IMAGE_FILE_SIGNATURE_LENGTH 4

static HANDLE main_process;
static HANDLE main_thread;
static int    main_thread_id;

static FILETIME process_creation_time;
static FILETIME process_exit_time;
static FILETIME process_user_time;
static FILETIME process_kernel_time;

#if defined(_M_ARM64)
  #define __CPU__ aarch64
#elif defined(_M_AMD64)
  #define __CPU__ amd64
#else
  #define __CPU__ i486
#endif

#if defined(USE_VECTORED_EXCEPTION_HANDLING)
PVOID  topLevelVectoredExceptionHandler = NULL;
LPTOP_LEVEL_EXCEPTION_FILTER previousUnhandledExceptionFilter = NULL;
#endif

// save DLL module handle, used by GetModuleFileName

HINSTANCE vm_lib_handle;

BOOL WINAPI DllMain(HINSTANCE hinst, DWORD reason, LPVOID reserved) {
  switch (reason) {
  case DLL_PROCESS_ATTACH:
    vm_lib_handle = hinst;
    if (ForceTimeHighResolution) {
      timeBeginPeriod(1L);
    }
    WindowsDbgHelp::pre_initialize();
    SymbolEngine::pre_initialize();
    break;
  case DLL_PROCESS_DETACH:
    if (ForceTimeHighResolution) {
      timeEndPeriod(1L);
    }
#if defined(USE_VECTORED_EXCEPTION_HANDLING)
    if (topLevelVectoredExceptionHandler != NULL) {
      RemoveVectoredExceptionHandler(topLevelVectoredExceptionHandler);
      topLevelVectoredExceptionHandler = NULL;
    }
#endif
    break;
  default:
    break;
  }
  return true;
}

static inline double fileTimeAsDouble(FILETIME* time) {
  const double high  = (double) ((unsigned int) ~0);
  const double split = 10000000.0;
  double result = (time->dwLowDateTime / split) +
                   time->dwHighDateTime * (high/split);
  return result;
}

// Implementation of os

#define RANGE_FORMAT                "[" PTR_FORMAT "-" PTR_FORMAT ")"
#define RANGE_FORMAT_ARGS(p, len)   p2i(p), p2i((address)p + len)

// A number of wrappers for more frequently used system calls, to add standard logging.

struct PreserveLastError {
  const DWORD v;
  PreserveLastError() : v(::GetLastError()) {}
  ~PreserveLastError() { ::SetLastError(v); }
};

// Logging wrapper for VirtualAlloc
static LPVOID virtualAlloc(LPVOID lpAddress, SIZE_T dwSize, DWORD flAllocationType, DWORD flProtect) {
  LPVOID result = ::VirtualAlloc(lpAddress, dwSize, flAllocationType, flProtect);
  if (result != NULL) {
    log_trace(os)("VirtualAlloc(" PTR_FORMAT ", " SIZE_FORMAT ", %x, %x) returned " PTR_FORMAT "%s.",
                  p2i(lpAddress), dwSize, flAllocationType, flProtect, p2i(result),
                  ((lpAddress != NULL && result != lpAddress) ? " " : ""));
  } else {
    PreserveLastError ple;
    log_info(os)("VirtualAlloc(" PTR_FORMAT ", " SIZE_FORMAT ", %x, %x) failed (%u).",
                  p2i(lpAddress), dwSize, flAllocationType, flProtect, ple.v);
  }
  return result;
}

// Logging wrapper for VirtualFree
static BOOL virtualFree(LPVOID lpAddress, SIZE_T dwSize, DWORD  dwFreeType) {
  BOOL result = ::VirtualFree(lpAddress, dwSize, dwFreeType);
  if (result != FALSE) {
    log_trace(os)("VirtualFree(" PTR_FORMAT ", " SIZE_FORMAT ", %x) succeeded",
                  p2i(lpAddress), dwSize, dwFreeType);
  } else {
    PreserveLastError ple;
    log_info(os)("VirtualFree(" PTR_FORMAT ", " SIZE_FORMAT ", %x) failed (%u).",
                 p2i(lpAddress), dwSize, dwFreeType, ple.v);
  }
  return result;
}

// Logging wrapper for VirtualAllocExNuma
static LPVOID virtualAllocExNuma(HANDLE hProcess, LPVOID lpAddress, SIZE_T dwSize, DWORD  flAllocationType,
                                 DWORD  flProtect, DWORD  nndPreferred) {
  LPVOID result = ::VirtualAllocExNuma(hProcess, lpAddress, dwSize, flAllocationType, flProtect, nndPreferred);
  if (result != NULL) {
    log_trace(os)("VirtualAllocExNuma(" PTR_FORMAT ", " SIZE_FORMAT ", %x, %x, %x) returned " PTR_FORMAT "%s.",
                  p2i(lpAddress), dwSize, flAllocationType, flProtect, nndPreferred, p2i(result),
                  ((lpAddress != NULL && result != lpAddress) ? " " : ""));
  } else {
    PreserveLastError ple;
    log_info(os)("VirtualAllocExNuma(" PTR_FORMAT ", " SIZE_FORMAT ", %x, %x, %x) failed (%u).",
                 p2i(lpAddress), dwSize, flAllocationType, flProtect, nndPreferred, ple.v);
  }
  return result;
}

// Logging wrapper for MapViewOfFileEx
static LPVOID mapViewOfFileEx(HANDLE hFileMappingObject, DWORD  dwDesiredAccess, DWORD  dwFileOffsetHigh,
                              DWORD  dwFileOffsetLow, SIZE_T dwNumberOfBytesToMap, LPVOID lpBaseAddress) {
  LPVOID result = ::MapViewOfFileEx(hFileMappingObject, dwDesiredAccess, dwFileOffsetHigh,
                                    dwFileOffsetLow, dwNumberOfBytesToMap, lpBaseAddress);
  if (result != NULL) {
    log_trace(os)("MapViewOfFileEx(" PTR_FORMAT ", " SIZE_FORMAT ") returned " PTR_FORMAT "%s.",
                  p2i(lpBaseAddress), dwNumberOfBytesToMap, p2i(result),
                  ((lpBaseAddress != NULL && result != lpBaseAddress) ? " " : ""));
  } else {
    PreserveLastError ple;
    log_info(os)("MapViewOfFileEx(" PTR_FORMAT ", " SIZE_FORMAT ") failed (%u).",
                 p2i(lpBaseAddress), dwNumberOfBytesToMap, ple.v);
  }
  return result;
}

// Logging wrapper for UnmapViewOfFile
static BOOL unmapViewOfFile(LPCVOID lpBaseAddress) {
  BOOL result = ::UnmapViewOfFile(lpBaseAddress);
  if (result != FALSE) {
    log_trace(os)("UnmapViewOfFile(" PTR_FORMAT ") succeeded", p2i(lpBaseAddress));
  } else {
    PreserveLastError ple;
    log_info(os)("UnmapViewOfFile(" PTR_FORMAT ") failed (%u).",  p2i(lpBaseAddress), ple.v);
  }
  return result;
}

char** os::get_environ() { return _environ; }

// No setuid programs under Windows.
bool os::have_special_privileges() {
  return false;
}

// This method is a periodic task to check for misbehaving JNI applications
// under CheckJNI, we can add any periodic checks here.
// For Windows at the moment does nothing
void os::run_periodic_checks(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);

void os::init_system_properties_values() {
  // sysclasspath, java_home, dll_dir
  {
    char *home_path;
    char *dll_path;
    char *pslash;
    const char *bin = "\\bin";
    char home_dir[MAX_PATH + 1];
    char *alt_home_dir = ::getenv("_ALT_JAVA_HOME_DIR");

    if (alt_home_dir != NULL)  {
      strncpy(home_dir, alt_home_dir, MAX_PATH + 1);
      home_dir[MAX_PATH] = '\0';
    } else {
      os::jvm_path(home_dir, sizeof(home_dir));
      // Found the full path to jvm.dll.
      // Now cut the path to <java_home>/jre if we can.
      *(strrchr(home_dir, '\\')) = '\0';  // get rid of \jvm.dll
      pslash = strrchr(home_dir, '\\');
      if (pslash != NULL) {
        *pslash = '\0';                   // get rid of \{client|server}
        pslash = strrchr(home_dir, '\\');
        if (pslash != NULL) {
          *pslash = '\0';                 // get rid of \bin
        }
      }
    }

    home_path = NEW_C_HEAP_ARRAY(char, strlen(home_dir) + 1, mtInternal);
    strcpy(home_path, home_dir);
    Arguments::set_java_home(home_path);
    FREE_C_HEAP_ARRAY(char, home_path);

    dll_path = NEW_C_HEAP_ARRAY(char, strlen(home_dir) + strlen(bin) + 1,
                                mtInternal);
    strcpy(dll_path, home_dir);
    strcat(dll_path, bin);
    Arguments::set_dll_dir(dll_path);
    FREE_C_HEAP_ARRAY(char, dll_path);

    if (!set_boot_path('\\', ';')) {
      vm_exit_during_initialization("Failed setting boot class path.", NULL);
    }
  }

// library_path
#define EXT_DIR "\\lib\\ext"
#define BIN_DIR "\\bin"
#define PACKAGE_DIR "\\Sun\\Java"
  {
    // Win32 library search order (See the documentation for LoadLibrary):
    //
    // 1. The directory from which application is loaded.
    // 2. The system wide Java Extensions directory (Java only)
    // 3. System directory (GetSystemDirectory)
    // 4. Windows directory (GetWindowsDirectory)
    // 5. The PATH environment variable
    // 6. The current directory

    char *library_path;
    char tmp[MAX_PATH];
    char *path_str = ::getenv("PATH");

    library_path = NEW_C_HEAP_ARRAY(char, MAX_PATH * 5 + sizeof(PACKAGE_DIR) +
                                    sizeof(BIN_DIR) + (path_str ? strlen(path_str) : 0) + 10, mtInternal);

    library_path[0] = '\0';

    GetModuleFileName(NULL, tmp, sizeof(tmp));
    *(strrchr(tmp, '\\')) = '\0';
    strcat(library_path, tmp);

    GetWindowsDirectory(tmp, sizeof(tmp));
    strcat(library_path, ";");
    strcat(library_path, tmp);
    strcat(library_path, PACKAGE_DIR BIN_DIR);

    GetSystemDirectory(tmp, sizeof(tmp));
    strcat(library_path, ";");
    strcat(library_path, tmp);

    GetWindowsDirectory(tmp, sizeof(tmp));
    strcat(library_path, ";");
    strcat(library_path, tmp);

    if (path_str) {
      strcat(library_path, ";");
      strcat(library_path, path_str);
    }

    strcat(library_path, ";.");

    Arguments::set_library_path(library_path);
    FREE_C_HEAP_ARRAY(char, library_path);
  }

  // Default extensions directory
  {
    char path[MAX_PATH];
    char buf[2 * MAX_PATH + 2 * sizeof(EXT_DIR) + sizeof(PACKAGE_DIR) + 1];
    GetWindowsDirectory(path, MAX_PATH);
    sprintf(buf, "%s%s;%s%s%s", Arguments::get_java_home(), EXT_DIR,
            path, PACKAGE_DIR, EXT_DIR);
    Arguments::set_ext_dirs(buf);
  }
  #undef EXT_DIR
  #undef BIN_DIR
  #undef PACKAGE_DIR

#ifndef _WIN64
  // set our UnhandledExceptionFilter and save any previous one
  prev_uef_handler = SetUnhandledExceptionFilter(Handle_FLT_Exception);
#endif

  // Done
  return;
}

void os::breakpoint() {
  DebugBreak();
}

// Invoked from the BREAKPOINT Macro
extern "C" void breakpoint() {
  os::breakpoint();
}

// RtlCaptureStackBackTrace Windows API may not exist prior to Windows XP.
// So far, this method is only used by Native Memory Tracking, which is
// only supported on Windows XP or later.
//
int os::get_native_stack(address* stack, int frames, int toSkip) {
  int captured = RtlCaptureStackBackTrace(toSkip + 1, frames, (PVOID*)stack, NULL);
  for (int index = captured; index < frames; index ++) {
    stack[index] = NULL;
  }
  return captured;
}

// os::current_stack_base()
//
//   Returns the base of the stack, which is the stack's
//   starting address.  This function must be called
//   while running on the stack of the thread being queried.

address os::current_stack_base() {
  MEMORY_BASIC_INFORMATION minfo;
  address stack_bottom;
  size_t stack_size;

  VirtualQuery(&minfo, &minfo, sizeof(minfo));
  stack_bottom =  (address)minfo.AllocationBase;
  stack_size = minfo.RegionSize;

  // Add up the sizes of all the regions with the same
  // AllocationBase.
  while (1) {
    VirtualQuery(stack_bottom+stack_size, &minfo, sizeof(minfo));
    if (stack_bottom == (address)minfo.AllocationBase) {
      stack_size += minfo.RegionSize;
    } else {
      break;
    }
  }
  return stack_bottom + stack_size;
}

size_t os::current_stack_size() {
  size_t sz;
  MEMORY_BASIC_INFORMATION minfo;
  VirtualQuery(&minfo, &minfo, sizeof(minfo));
  sz = (size_t)os::current_stack_base() - (size_t)minfo.AllocationBase;
  return sz;
}

bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) {
  MEMORY_BASIC_INFORMATION minfo;
  committed_start = NULL;
  committed_size = 0;
  address top = start + size;
  const address start_addr = start;
  while (start < top) {
    VirtualQuery(start, &minfo, sizeof(minfo));
    if ((minfo.State & MEM_COMMIT) == 0) {  // not committed
      if (committed_start != NULL) {
        break;
      }
    } else {  // committed
      if (committed_start == NULL) {
        committed_start = start;
      }
      size_t offset = start - (address)minfo.BaseAddress;
      committed_size += minfo.RegionSize - offset;
    }
    start = (address)minfo.BaseAddress + minfo.RegionSize;
  }

  if (committed_start == NULL) {
    assert(committed_size == 0, "Sanity");
    return false;
  } else {
    assert(committed_start >= start_addr && committed_start < top, "Out of range");
    // current region may go beyond the limit, trim to the limit
    committed_size = MIN2(committed_size, size_t(top - committed_start));
    return true;
  }
}

struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
  const struct tm* time_struct_ptr = localtime(clock);
  if (time_struct_ptr != NULL) {
    *res = *time_struct_ptr;
    return res;
  }
  return NULL;
}

struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
  const struct tm* time_struct_ptr = gmtime(clock);
  if (time_struct_ptr != NULL) {
    *res = *time_struct_ptr;
    return res;
  }
  return NULL;
}

JNIEXPORT
LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo);

// Thread start routine for all newly created threads
static unsigned __stdcall thread_native_entry(Thread* thread) {

  thread->record_stack_base_and_size();
  thread->initialize_thread_current();

  OSThread* osthr = thread->osthread();
  assert(osthr->get_state() == RUNNABLE, "invalid os thread state");

  if (UseNUMA) {
    int lgrp_id = os::numa_get_group_id();
    if (lgrp_id != -1) {
      thread->set_lgrp_id(lgrp_id);
    }
  }

  // Diagnostic code to investigate JDK-6573254
  int res = 30115;  // non-java thread
  if (thread->is_Java_thread()) {
    res = 20115;    // java thread
  }

  log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", stacksize: " SIZE_FORMAT "k).", os::current_thread_id(), thread->stack_size() / K);

#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.

  log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ").", os::current_thread_id());

  // 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);

  return osthread;
}

bool os::create_attached_thread(JavaThread* thread) {
#ifdef ASSERT
  thread->verify_not_published();
#endif
  HANDLE thread_h;
  if (!DuplicateHandle(main_process, GetCurrentThread(), GetCurrentProcess(),
                       &thread_h, THREAD_ALL_ACCESS, false, 0)) {
    fatal("DuplicateHandle failed\n");
  }
  OSThread* osthread = create_os_thread(thread, thread_h,
                                        (int)current_thread_id());
  if (osthread == NULL) {
    return false;
  }

  // Initial thread state is RUNNABLE
  osthread->set_state(RUNNABLE);

  thread->set_osthread(osthread);

  log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", stack: "
                       PTR_FORMAT " - " PTR_FORMAT " (" SIZE_FORMAT "k) ).",
                       os::current_thread_id(), p2i(thread->stack_base()),
                       p2i(thread->stack_end()), thread->stack_size());

  return true;
}

bool os::create_main_thread(JavaThread* thread) {
#ifdef ASSERT
  thread->verify_not_published();
#endif
  if (_starting_thread == NULL) {
    _starting_thread = create_os_thread(thread, main_thread, main_thread_id);
    if (_starting_thread == NULL) {
      return false;
    }
  }

  // The primordial thread is runnable from the start)
  _starting_thread->set_state(RUNNABLE);

  thread->set_osthread(_starting_thread);
  return true;
}

// Helper function to trace _beginthreadex attributes,
//  similar to os::Posix::describe_pthread_attr()
static char* describe_beginthreadex_attributes(char* buf, size_t buflen,
                                               size_t stacksize, unsigned initflag) {
  stringStream ss(buf, buflen);
  if (stacksize == 0) {
    ss.print("stacksize: default, ");
  } else {
    ss.print("stacksize: " SIZE_FORMAT "k, ", stacksize / 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) {
    return false;
  }

  // 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;
    return false;
  }
  osthread->set_interrupt_event(interrupt_event);
  // We don't call set_interrupted(false) as it will trip the assert in there
  // as we are not operating on the current thread. We don't need to call it
  // because the initial state is already correct.

  thread->set_osthread(osthread);

  if (stack_size == 0) {
    switch (thr_type) {
    case os::java_thread:
      // Java threads use ThreadStackSize which default value can be changed with the flag -Xss
      if (JavaThread::stack_size_at_create() > 0) {
        stack_size = JavaThread::stack_size_at_create();
      }
      break;
    case os::compiler_thread:
      if (CompilerThreadStackSize > 0) {
        stack_size = (size_t)(CompilerThreadStackSize * K);
        break;
      } // else fall through:
        // use VMThreadStackSize if CompilerThreadStackSize is not defined
    case os::vm_thread:
    case os::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.

  const unsigned initflag = CREATE_SUSPENDED | STACK_SIZE_PARAM_IS_A_RESERVATION;
  HANDLE thread_handle;
  int limit = 3;
  do {
    thread_handle =
      (HANDLE)_beginthreadex(NULL,
                             (unsigned)stack_size,
                             (unsigned (__stdcall *)(void*)) thread_native_entry,
                             thread,
                             initflag,
                             &thread_id);
  } while (thread_handle == NULL && errno == EAGAIN && limit-- > 0);

  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;
    return false;
  }

  // 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
  return true;
}

// Free Win32 resources related to the OSThread
void os::free_thread(OSThread* osthread) {
  assert(osthread != NULL, "osthread not set");

  // We are told to free resources of the argument thread,
  // but we can only really operate on the current thread.
  assert(Thread::current()->osthread() == osthread,
         "os::free_thread but not current thread");

  CloseHandle(osthread->thread_handle());
  delete osthread;
}

static jlong first_filetime;
static jlong initial_performance_count;
static jlong performance_frequency;

jlong as_long(LARGE_INTEGER x) {
  jlong result = 0; // initialization to avoid warning
  set_high(&result, x.HighPart);
  set_low(&result, x.LowPart);
  return result;
}

jlong os::elapsed_counter() {
  LARGE_INTEGER count;
  QueryPerformanceCounter(&count);
  return as_long(count) - initial_performance_count;
}

jlong os::elapsed_frequency() {
  return performance_frequency;
}

julong os::available_memory() {
  return win32::available_memory();
}

julong os::win32::available_memory() {
  // Use GlobalMemoryStatusEx() because GlobalMemoryStatus() may return incorrect
  // value if total memory is larger than 4GB
  MEMORYSTATUSEX ms;
  ms.dwLength = sizeof(ms);
  GlobalMemoryStatusEx(&ms);

  return (julong)ms.ullAvailPhys;
}

julong os::physical_memory() {
  return win32::physical_memory();
}

bool os::has_allocatable_memory_limit(size_t* limit) {
  MEMORYSTATUSEX ms;
  ms.dwLength = sizeof(ms);
  GlobalMemoryStatusEx(&ms);
#ifdef _LP64
  *limit = (size_t)ms.ullAvailVirtual;
  return true;
#else
  // Limit to 1400m because of the 2gb address space wall
  *limit = MIN2((size_t)1400*M, (size_t)ms.ullAvailVirtual);
  return true;
#endif
}

int os::active_processor_count() {
  // User has overridden the number of active processors
  if (ActiveProcessorCount > 0) {
    log_trace(os)("active_processor_count: "
                  "active processor count set by user : %d",
                  ActiveProcessorCount);
    return ActiveProcessorCount;
  }

  DWORD_PTR lpProcessAffinityMask = 0;
  DWORD_PTR lpSystemAffinityMask = 0;
  int proc_count = processor_count();
  if (proc_count <= sizeof(UINT_PTR) * BitsPerByte &&
      GetProcessAffinityMask(GetCurrentProcess(), &lpProcessAffinityMask, &lpSystemAffinityMask)) {
    // Nof active processors is number of bits in process affinity mask
    int bitcount = 0;
    while (lpProcessAffinityMask != 0) {
      lpProcessAffinityMask = lpProcessAffinityMask & (lpProcessAffinityMask-1);
      bitcount++;
    }
    return bitcount;
  } else {
    return proc_count;
  }
}

uint os::processor_id() {
  return (uint)GetCurrentProcessorNumber();
}

// For dynamic lookup of SetThreadDescription API
typedef HRESULT (WINAPI *SetThreadDescriptionFnPtr)(HANDLE, PCWSTR);
typedef HRESULT (WINAPI *GetThreadDescriptionFnPtr)(HANDLE, PWSTR*);
static SetThreadDescriptionFnPtr _SetThreadDescription = NULL;
DEBUG_ONLY(static GetThreadDescriptionFnPtr _GetThreadDescription = NULL;)

// forward decl.
static errno_t convert_to_unicode(char const* char_path, LPWSTR* unicode_path);

void os::set_native_thread_name(const char *name) {

  // From Windows 10 and Windows 2016 server, we have a direct API
  // for setting the thread name/description:
  // https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-setthreaddescription

  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;

  info.dwType = 0x1000;
  info.szName = name;
  info.dwThreadID = -1;
  info.dwFlags = 0;

  __try {
    RaiseException (MS_VC_EXCEPTION, 0, sizeof(info)/sizeof(DWORD), (const ULONG_PTR*)&info );
  } __except(EXCEPTION_EXECUTE_HANDLER) {}
}

void os::win32::initialize_performance_counter() {
  LARGE_INTEGER count;
  QueryPerformanceFrequency(&count);
  performance_frequency = as_long(count);
  QueryPerformanceCounter(&count);
  initial_performance_count = as_long(count);
}

double os::elapsedTime() {
  return (double) elapsed_counter() / (double) elapsed_frequency();
}

// Windows format:
//   The FILETIME structure is a 64-bit value representing the number of 100-nanosecond intervals since January 1, 1601.
// Java format:
//   Java standards require the number of milliseconds since 1/1/1970

// Constant offset - calculated using offset()
static jlong  _offset   = 116444736000000000;
// Fake time counter for reproducible results when debugging
static jlong  fake_time = 0;

#ifdef ASSERT
// Just to be safe, recalculate the offset in debug mode
static jlong _calculated_offset = 0;
static int   _has_calculated_offset = 0;

jlong offset() {
  if (_has_calculated_offset) return _calculated_offset;
  SYSTEMTIME java_origin;
  java_origin.wYear          = 1970;
  java_origin.wMonth         = 1;
  java_origin.wDayOfWeek     = 0; // ignored
  java_origin.wDay           = 1;
  java_origin.wHour          = 0;
  java_origin.wMinute        = 0;
  java_origin.wSecond        = 0;
  java_origin.wMilliseconds  = 0;
  FILETIME jot;
  if (!SystemTimeToFileTime(&java_origin, &jot)) {
    fatal("Error = %d\nWindows error", GetLastError());
  }
  _calculated_offset = jlong_from(jot.dwHighDateTime, jot.dwLowDateTime);
  _has_calculated_offset = 1;
  assert(_calculated_offset == _offset, "Calculated and constant time offsets must be equal");
  return _calculated_offset;
}
#else
jlong offset() {
  return _offset;
}
#endif

jlong windows_to_java_time(FILETIME wt) {
  jlong a = jlong_from(wt.dwHighDateTime, wt.dwLowDateTime);
  return (a - offset()) / 10000;
}

// Returns time ticks in (10th of micro seconds)
jlong windows_to_time_ticks(FILETIME wt) {
  jlong a = jlong_from(wt.dwHighDateTime, wt.dwLowDateTime);
  return (a - offset());
}

FILETIME java_to_windows_time(jlong l) {
  jlong a = (l * 10000) + offset();
  FILETIME result;
  result.dwHighDateTime = high(a);
  result.dwLowDateTime  = low(a);
  return result;
}

bool os::supports_vtime() { return true; }

double os::elapsedVTime() {
  FILETIME created;
  FILETIME exited;
  FILETIME kernel;
  FILETIME user;
  if (GetThreadTimes(GetCurrentThread(), &created, &exited, &kernel, &user) != 0) {
    // the resolution of windows_to_java_time() should be sufficient (ms)
    return (double) (windows_to_java_time(kernel) + windows_to_java_time(user)) / MILLIUNITS;
  } else {
    return elapsedTime();
  }
}

jlong os::javaTimeMillis() {
  FILETIME wt;
  GetSystemTimeAsFileTime(&wt);
  return windows_to_java_time(wt);
}

void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
  FILETIME wt;
  GetSystemTimeAsFileTime(&wt);
  jlong ticks = windows_to_time_ticks(wt); // 10th of micros
  jlong secs = jlong(ticks / 10000000); // 10000 * 1000
  seconds = secs;
  nanos = jlong(ticks - (secs*10000000)) * 100;
}

jlong os::javaTimeNanos() {
    LARGE_INTEGER current_count;
    QueryPerformanceCounter(¤t_count);
    double current = as_long(current_count);
    double freq = performance_frequency;
    jlong time = (jlong)((current/freq) * NANOSECS_PER_SEC);
    return time;
}

void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
  jlong freq = performance_frequency;
  if (freq < NANOSECS_PER_SEC) {
    // the performance counter is 64 bits and we will
    // be multiplying it -- so no wrap in 64 bits
    info_ptr->max_value = ALL_64_BITS;
  } else if (freq > NANOSECS_PER_SEC) {
    // use the max value the counter can reach to
    // determine the max value which could be returned
    julong max_counter = (julong)ALL_64_BITS;
    info_ptr->max_value = (jlong)(max_counter / (freq / NANOSECS_PER_SEC));
  } else {
    // the performance counter is 64 bits and we will
    // be using it directly -- so no wrap in 64 bits
    info_ptr->max_value = ALL_64_BITS;
  }

  // using a counter, so no skipping
  info_ptr->may_skip_backward = false;
  info_ptr->may_skip_forward = false;

  info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
}

char* os::local_time_string(char *buf, size_t buflen) {
  SYSTEMTIME st;
  GetLocalTime(&st);
  jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
               st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond);
  return buf;
}

bool os::getTimesSecs(double* process_real_time,
                      double* process_user_time,
                      double* process_system_time) {
  HANDLE h_process = GetCurrentProcess();
  FILETIME create_time, exit_time, kernel_time, user_time;
  BOOL result = GetProcessTimes(h_process,
                                &create_time,
                                &exit_time,
                                &kernel_time,
                                &user_time);
  if (result != 0) {
    FILETIME wt;
    GetSystemTimeAsFileTime(&wt);
    jlong rtc_millis = windows_to_java_time(wt);
    *process_real_time = ((double) rtc_millis) / ((double) MILLIUNITS);
    *process_user_time =
      (double) jlong_from(user_time.dwHighDateTime, user_time.dwLowDateTime) / (10 * MICROUNITS);
    *process_system_time =
      (double) jlong_from(kernel_time.dwHighDateTime, kernel_time.dwLowDateTime) / (10 * MICROUNITS);
    return true;
  } else {
    return false;
  }
}

void os::shutdown() {
  // allow PerfMemory to attempt cleanup of any persistent resources
  perfMemory_exit();

  // flush buffered output, finish log files
  ostream_abort();

  // Check for abort hook
  abort_hook_t abort_hook = Arguments::abort_hook();
  if (abort_hook != NULL) {
    abort_hook();
  }
}

static HANDLE dumpFile = NULL;

// Check if dump file can be created.
void os::check_dump_limit(char* buffer, size_t buffsz) {
  bool status = true;
  if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
    jio_snprintf(buffer, buffsz, "CreateCoredumpOnCrash is disabled from command line");
    status = false;
  }

#ifndef ASSERT
  if (!os::win32::is_windows_server() && FLAG_IS_DEFAULT(CreateCoredumpOnCrash)) {
    jio_snprintf(buffer, buffsz, "Minidumps are not enabled by default on client versions of Windows");
    status = false;
  }
#endif

  if (status) {
    const char* cwd = get_current_directory(NULL, 0);
    int pid = current_process_id();
    if (cwd != NULL) {
      jio_snprintf(buffer, buffsz, "%s\\hs_err_pid%u.mdmp", cwd, pid);
    } else {
      jio_snprintf(buffer, buffsz, ".\\hs_err_pid%u.mdmp", pid);
    }

    if (dumpFile == NULL &&
       (dumpFile = CreateFile(buffer, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL))
                 == INVALID_HANDLE_VALUE) {
      jio_snprintf(buffer, buffsz, "Failed to create minidump file (0x%x).", GetLastError());
      status = false;
    }
  }
  VMError::record_coredump_status(buffer, status);
}

void os::abort(bool dump_core, void* siginfo, const void* context) {
  EXCEPTION_POINTERS ep;
  MINIDUMP_EXCEPTION_INFORMATION mei;
  MINIDUMP_EXCEPTION_INFORMATION* pmei;

  HANDLE hProcess = GetCurrentProcess();
  DWORD processId = GetCurrentProcessId();
  MINIDUMP_TYPE dumpType;

  shutdown();
  if (!dump_core || dumpFile == NULL) {
    if (dumpFile != NULL) {
      CloseHandle(dumpFile);
    }
    win32::exit_process_or_thread(win32::EPT_PROCESS, 1);
  }

  dumpType = (MINIDUMP_TYPE)(MiniDumpWithFullMemory | MiniDumpWithHandleData |
    MiniDumpWithFullMemoryInfo | MiniDumpWithThreadInfo | MiniDumpWithUnloadedModules);

  if (siginfo != NULL && context != NULL) {
    ep.ContextRecord = (PCONTEXT) context;
    ep.ExceptionRecord = (PEXCEPTION_RECORD) siginfo;

    mei.ThreadId = GetCurrentThreadId();
    mei.ExceptionPointers = &ep;
    pmei = &mei;
  } else {
    pmei = NULL;
  }

  // Older versions of dbghelp.dll (the one shipped with Win2003 for example) may not support all
  // the dump types we really want. If first call fails, lets fall back to just use MiniDumpWithFullMemory then.
  if (!WindowsDbgHelp::miniDumpWriteDump(hProcess, processId, dumpFile, dumpType, pmei, NULL, NULL) &&
      !WindowsDbgHelp::miniDumpWriteDump(hProcess, processId, dumpFile, (MINIDUMP_TYPE)MiniDumpWithFullMemory, pmei, NULL, NULL)) {
    jio_fprintf(stderr, "Call to MiniDumpWriteDump() failed (Error 0x%x)\n", GetLastError());
  }
  CloseHandle(dumpFile);
  win32::exit_process_or_thread(win32::EPT_PROCESS, 1);
}

// Die immediately, no exit hook, no abort hook, no cleanup.
void os::die() {
  win32::exit_process_or_thread(win32::EPT_PROCESS_DIE, -1);
}

void  os::dll_unload(void *lib) {
  char name[MAX_PATH];
  if (::GetModuleFileName((HMODULE)lib, name, sizeof(name)) == 0) {
    snprintf(name, MAX_PATH, "");
  }
  if (::FreeLibrary((HMODULE)lib)) {
    Events::log_dll_message(NULL, "Unloaded dll \"%s\" [" INTPTR_FORMAT "]", name, p2i(lib));
    log_info(os)("Unloaded dll \"%s\" [" INTPTR_FORMAT "]", name, p2i(lib));
  } else {
    const DWORD errcode = ::GetLastError();
    Events::log_dll_message(NULL, "Attempt to unload dll \"%s\" [" INTPTR_FORMAT "] failed (error code %d)", name, p2i(lib), errcode);
    log_info(os)("Attempt to unload dll \"%s\" [" INTPTR_FORMAT "] failed (error code %d)", name, p2i(lib), errcode);
  }
}

void* os::dll_lookup(void *lib, const char *name) {
  return (void*)::GetProcAddress((HMODULE)lib, name);
}

// Directory routines copied from src/win32/native/java/io/dirent_md.c
//  * dirent_md.c       1.15 00/02/02
//
// The declarations for DIR and struct dirent are in jvm_win32.h.

// Caller must have already run dirname through JVM_NativePath, which removes
// duplicate slashes and converts all instances of '/' into '\\'.

DIR * os::opendir(const char *dirname) {
  assert(dirname != NULL, "just checking");   // hotspot change
  DIR *dirp = (DIR *)malloc(sizeof(DIR), mtInternal);
  DWORD fattr;                                // hotspot change
  char alt_dirname[4] = { 0, 0, 0, 0 };

  if (dirp == 0) {
    errno = ENOMEM;
    return 0;
  }

  // Win32 accepts "\" in its POSIX stat(), but refuses to treat it
  // as a directory in FindFirstFile().  We detect this case here and
  // prepend the current drive name.
  //
  if (dirname[1] == '\0' && dirname[0] == '\\') {
    alt_dirname[0] = _getdrive() + 'A' - 1;
    alt_dirname[1] = ':';
    alt_dirname[2] = '\\';
    alt_dirname[3] = '\0';
    dirname = alt_dirname;
  }

  dirp->path = (char *)malloc(strlen(dirname) + 5, mtInternal);
  if (dirp->path == 0) {
    free(dirp);
    errno = ENOMEM;
    return 0;
  }
  strcpy(dirp->path, dirname);

  fattr = GetFileAttributes(dirp->path);
  if (fattr == 0xffffffff) {
    free(dirp->path);
    free(dirp);
    errno = ENOENT;
    return 0;
  } else if ((fattr & FILE_ATTRIBUTE_DIRECTORY) == 0) {
    free(dirp->path);
    free(dirp);
    errno = ENOTDIR;
    return 0;
  }

  // Append "*.*", or possibly "\\*.*", to path
  if (dirp->path[1] == ':' &&
      (dirp->path[2] == '\0' ||
      (dirp->path[2] == '\\' && dirp->path[3] == '\0'))) {
    // No '\\' needed for cases like "Z:" or "Z:\"
    strcat(dirp->path, "*.*");
  } else {
    strcat(dirp->path, "\\*.*");
  }

  dirp->handle = FindFirstFile(dirp->path, &dirp->find_data);
  if (dirp->handle == INVALID_HANDLE_VALUE) {
    if (GetLastError() != ERROR_FILE_NOT_FOUND) {
      free(dirp->path);
      free(dirp);
      errno = EACCES;
      return 0;
    }
  }
  return dirp;
}

struct dirent * os::readdir(DIR *dirp) {
  assert(dirp != NULL, "just checking");      // hotspot change
  if (dirp->handle == INVALID_HANDLE_VALUE) {
    return NULL;
  }

  strcpy(dirp->dirent.d_name, dirp->find_data.cFileName);

  if (!FindNextFile(dirp->handle, &dirp->find_data)) {
    if (GetLastError() == ERROR_INVALID_HANDLE) {
      errno = EBADF;
      return NULL;
    }
    FindClose(dirp->handle);
    dirp->handle = INVALID_HANDLE_VALUE;
  }

  return &dirp->dirent;
}

int os::closedir(DIR *dirp) {
  assert(dirp != NULL, "just checking");      // hotspot change
  if (dirp->handle != INVALID_HANDLE_VALUE) {
    if (!FindClose(dirp->handle)) {
      errno = EBADF;
      return -1;
    }
    dirp->handle = INVALID_HANDLE_VALUE;
  }
  free(dirp->path);
  free(dirp);
  return 0;
}

// This must be hard coded because it's the system's temporary
// directory not the java application's temp directory, ala java.io.tmpdir.
const char* os::get_temp_directory() {
  static char path_buf[MAX_PATH];
  if (GetTempPath(MAX_PATH, path_buf) > 0) {
    return path_buf;
  } else {
    path_buf[0] = '\0';
    return path_buf;
  }
}

// Needs to be in os specific directory because windows requires another
// header file <direct.h>
const char* os::get_current_directory(char *buf, size_t buflen) {
  int n = static_cast<int>(buflen);
  if (buflen > INT_MAX)  n = INT_MAX;
  return _getcwd(buf, n);
}

//-----------------------------------------------------------
// Helper functions for fatal error handler
#ifdef _WIN64
// Helper routine which returns true if address in
// within the NTDLL address space.
//
static bool _addr_in_ntdll(address addr) {
  HMODULE hmod;
  MODULEINFO minfo;

  hmod = GetModuleHandle("NTDLL.DLL");
  if (hmod == NULL) return false;
  if (!GetModuleInformation(GetCurrentProcess(), hmod,
                                          &minfo, sizeof(MODULEINFO))) {
    return false;
  }

  if ((addr >= minfo.lpBaseOfDll) &&
      (addr < (address)((uintptr_t)minfo.lpBaseOfDll + (uintptr_t)minfo.SizeOfImage))) {
    return true;
  } else {
    return false;
  }
}
#endif

struct _modinfo {
  address addr;
  char*   full_path;   // point to a char buffer
  int     buflen;      // size of the buffer
  address base_addr;
};

static int _locate_module_by_addr(const char * mod_fname, address base_addr,
                                  address top_address, void * param) {
  struct _modinfo *pmod = (struct _modinfo *)param;
  if (!pmod) return -1;

  if (base_addr   <= pmod->addr &&
      top_address > pmod->addr) {
    // if a buffer is provided, copy path name to the buffer
    if (pmod->full_path) {
      jio_snprintf(pmod->full_path, pmod->buflen, "%s", mod_fname);
    }
    pmod->base_addr = base_addr;
    return 1;
  }
  return 0;
}

bool os::dll_address_to_library_name(address addr, char* buf,
                                     int buflen, int* offset) {
  // buf is not optional, but offset is optional
  assert(buf != NULL, "sanity check");

// NOTE: the reason we don't use SymGetModuleInfo() is it doesn't always
//       return the full path to the DLL file, sometimes it returns path
//       to the corresponding PDB file (debug info); sometimes it only
//       returns partial path, which makes life painful.

  struct _modinfo mi;
  mi.addr      = addr;
  mi.full_path = buf;
  mi.buflen    = buflen;
  if (get_loaded_modules_info(_locate_module_by_addr, (void *)&mi)) {
    // buf already contains path name
    if (offset) *offset = addr - mi.base_addr;
    return true;
  }

  buf[0] = '\0';
  if (offset) *offset = -1;
  return false;
}

bool os::dll_address_to_function_name(address addr, char *buf,
                                      int buflen, int *offset,
                                      bool demangle) {
  // buf is not optional, but offset is optional
  assert(buf != NULL, "sanity check");

  if (Decoder::decode(addr, buf, buflen, offset, demangle)) {
    return true;
  }
  if (offset != NULL)  *offset  = -1;
  buf[0] = '\0';
  return false;
}

// save the start and end address of jvm.dll into param[0] and param[1]
static int _locate_jvm_dll(const char* mod_fname, address base_addr,
                           address top_address, void * param) {
  if (!param) return -1;

  if (base_addr   <= (address)_locate_jvm_dll &&
      top_address > (address)_locate_jvm_dll) {
    ((address*)param)[0] = base_addr;
    ((address*)param)[1] = top_address;
    return 1;
  }
  return 0;
}

address vm_lib_location[2];    // start and end address of jvm.dll

// check if addr is inside jvm.dll
bool os::address_is_in_vm(address addr) {
  if (!vm_lib_location[0] || !vm_lib_location[1]) {
    if (!get_loaded_modules_info(_locate_jvm_dll, (void *)vm_lib_location)) {
      assert(false, "Can't find jvm module.");
      return false;
    }
  }

  return (vm_lib_location[0] <= addr) && (addr < vm_lib_location[1]);
}

// print module info; param is outputStream*
static int _print_module(const char* fname, address base_address,
                         address top_address, void* param) {
  if (!param) return -1;

  outputStream* st = (outputStream*)param;

  st->print(PTR_FORMAT " - " PTR_FORMAT " \t%s\n", base_address, top_address, fname);
  return 0;
}

// Loads .dll/.so and
// in case of error it checks if .dll/.so was built for the
// same architecture as Hotspot is running on
void * os::dll_load(const char *name, char *ebuf, int ebuflen) {
  log_info(os)("attempting shared library load of %s", name);

  void * result = LoadLibrary(name);
  if (result != NULL) {
    Events::log_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);

  if (errcode == ERROR_MOD_NOT_FOUND) {
    strncpy(ebuf, "Can't find dependent libraries", ebuflen - 1);
    ebuf[ebuflen - 1] = '\0';
    return NULL;
  }

  // Parsing dll below
  // If we can read dll-info and find that dll was built
  // for an architecture other than Hotspot is running in
  // - then print to buffer "DLL was built for a different architecture"
  // else call os::lasterror to obtain system error message
  int fd = ::open(name, O_RDONLY | O_BINARY, 0);
  if (fd < 0) {
    return NULL;
  }

  uint32_t signature_offset;
  uint16_t lib_arch = 0;
  bool failed_to_get_lib_arch =
    ( // Go to position 3c in the dll
     (os::seek_to_file_offset(fd, IMAGE_FILE_PTR_TO_SIGNATURE) < 0)
     ||
     // Read location of signature
     (sizeof(signature_offset) !=
     (::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))))
    );

  ::close(fd);
  if (failed_to_get_lib_arch) {
    // file i/o error - report os::lasterror(...) msg
    return NULL;
  }

  typedef struct {
    uint16_t arch_code;
    char* arch_name;
  } arch_t;

  static const arch_t arch_array[] = {
    {IMAGE_FILE_MACHINE_I386,      (char*)"IA 32"},
    {IMAGE_FILE_MACHINE_AMD64,     (char*)"AMD 64"},
    {IMAGE_FILE_MACHINE_ARM64,     (char*)"ARM 64"}
  };
#if (defined _M_ARM64)
  static const uint16_t running_arch = IMAGE_FILE_MACHINE_ARM64;
#elif (defined _M_AMD64)
  static const uint16_t running_arch = IMAGE_FILE_MACHINE_AMD64;
#elif (defined _M_IX86)
  static const uint16_t running_arch = IMAGE_FILE_MACHINE_I386;
#else
  #error Method os::dll_load requires that one of following \
         is defined :_M_AMD64 or _M_IX86 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 (unsigned int i = 0; i < ARRAY_SIZE(arch_array); i++) {
    if (lib_arch == arch_array[i].arch_code) {
      lib_arch_str = arch_array[i].arch_name;
    }
    if (running_arch == arch_array[i].arch_code) {
      running_arch_str = arch_array[i].arch_name;
    }
  }

  assert(running_arch_str,
         "Didn't find running architecture code in arch_array");

  // If the architecture is right
  // but some other error took place - report os::lasterror(...) msg
  if (lib_arch == running_arch) {
    return NULL;
  }

  if (lib_arch_str != NULL) {
    ::_snprintf(ebuf, ebuflen - 1,
                "Can't load %s-bit .dll on a %s-bit platform",
                lib_arch_str, running_arch_str);
  } else {
    // don't know what architecture this dll was build for
    ::_snprintf(ebuf, ebuflen - 1,
                "Can't load this .dll (machine code=0x%x) on a %s-bit platform",
                lib_arch, running_arch_str);
  }

  return NULL;
}

void os::print_dll_info(outputStream *st) {
  st->print_cr("Dynamic libraries:");
  get_loaded_modules_info(_print_module, (void *)st);
}

int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
  HANDLE   hProcess;

# define MAX_NUM_MODULES 128
  HMODULE     modules[MAX_NUM_MODULES];
  static char filename[MAX_PATH];
  int         result = 0;

  int pid = os::current_process_id();
  hProcess = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ,
                         FALSE, pid);
  if (hProcess == NULL) return 0;

  DWORD size_needed;
  if (!EnumProcessModules(hProcess, modules, sizeof(modules), &size_needed)) {
    CloseHandle(hProcess);
    return 0;
  }

  // number of modules that are currently loaded
  int num_modules = size_needed / sizeof(HMODULE);

  for (int i = 0; i < MIN2(num_modules, MAX_NUM_MODULES); i++) {
    // Get Full pathname:
    if (!GetModuleFileNameEx(hProcess, modules[i], filename, sizeof(filename))) {
      filename[0] = '\0';
    }

    MODULEINFO modinfo;
    if (!GetModuleInformation(hProcess, modules[i], &modinfo, sizeof(modinfo))) {
      modinfo.lpBaseOfDll = NULL;
      modinfo.SizeOfImage = 0;
    }

    // Invoke callback function
    result = callback(filename, (address)modinfo.lpBaseOfDll,
                      (address)((u8)modinfo.lpBaseOfDll + (u8)modinfo.SizeOfImage), param);
    if (result) break;
  }

  CloseHandle(hProcess);
  return result;
}

bool os::get_host_name(char* buf, size_t buflen) {
  DWORD size = (DWORD)buflen;
  return (GetComputerNameEx(ComputerNameDnsHostname, buf, &size) == TRUE);
}

void os::get_summary_os_info(char* buf, size_t buflen) {
  stringStream sst(buf, buflen);
  os::win32::print_windows_version(&sst);
  // chop off newline character
  char* nl = strchr(buf, '\n');
  if (nl != NULL) *nl = '\0';
}

int os::vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
  // 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;
}

static inline time_t get_mtime(const char* filename) {
  struct stat st;
  int ret = os::stat(filename, &st);
  assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
  return st.st_mtime;
}

int os::compare_file_modified_times(const char* file1, const char* file2) {
  time_t t1 = get_mtime(file1);
  time_t t2 = get_mtime(file2);
  return t1 - t2;
}

void os::print_os_info_brief(outputStream* st) {
  os::print_os_info(st);
}

void os::win32::print_uptime_info(outputStream* st) {
  unsigned long long ticks = GetTickCount64();
  os::print_dhm(st, "OS uptime:", ticks/1000);
}

void os::print_os_info(outputStream* st) {
#ifdef ASSERT
  char buffer[1024];
  st->print("HostName: ");
  if (get_host_name(buffer, sizeof(buffer))) {
    st->print_cr(buffer);
  } else {
    st->print_cr("N/A");
  }
#endif
  st->print_cr("OS:");
  os::win32::print_windows_version(st);

  os::win32::print_uptime_info(st);

  VM_Version::print_platform_virtualization_info(st);
}

void os::win32::print_windows_version(outputStream* st) {
  VS_FIXEDFILEINFO *file_info;
  TCHAR kernel32_path[MAX_PATH];
  UINT len, ret;

  bool is_workstation = !IsWindowsServer();

  // 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");
      } else if (build_number > 17762) {
        st->print("Server 2019");
      } else {
        st->print("Server 2016");
      }
    }
    break;

  default:
    // Unrecognized windows, print out its major and minor versions
    st->print("%d.%d", major_version, minor_version);
    break;
  }

  // Retrieve SYSTEM_INFO from GetNativeSystemInfo call so that we could
  // find out whether we are running on 64 bit processor or not
  SYSTEM_INFO si;
  ZeroMemory(&si, sizeof(SYSTEM_INFO));
  GetNativeSystemInfo(&si);
  if ((si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_AMD64) ||
      (si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_ARM64)) {
    st->print(" , 64 bit");
  }

  st->print(" Build %d", build_number);
  st->print(" (%d.%d.%d.%d)", major_version, minor_version, build_number, build_minor);
  st->cr();
}

void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
  // Nothing to do for now.
}

void os::get_summary_cpu_info(char* buf, size_t buflen) {
  HKEY key;
  DWORD status = RegOpenKey(HKEY_LOCAL_MACHINE,
               "HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0", &key);
  if (status == ERROR_SUCCESS) {
    DWORD size = (DWORD)buflen;
    status = RegQueryValueEx(key, "ProcessorNameString", NULL, NULL, (byte*)buf, &size);
    if (status != ERROR_SUCCESS) {
        strncpy(buf, "## __CPU__", buflen);
    }
    RegCloseKey(key);
  } else {
    // Put generic cpu info to return
    strncpy(buf, "## __CPU__", buflen);
  }
}

void os::print_memory_info(outputStream* st) {
  st->print("Memory:");
  st->print(" %dk page", os::vm_page_size()>>10);

  // Use GlobalMemoryStatusEx() because GlobalMemoryStatus() may return incorrect
  // value if total memory is larger than 4GB
  MEMORYSTATUSEX ms;
  ms.dwLength = sizeof(ms);
  int r1 = GlobalMemoryStatusEx(&ms);

  if (r1 != 0) {
    st->print(", system-wide physical " INT64_FORMAT "M ",
             (int64_t) ms.ullTotalPhys >> 20);
    st->print("(" INT64_FORMAT "M free)\n", (int64_t) ms.ullAvailPhys >> 20);

    st->print("TotalPageFile size " INT64_FORMAT "M ",
             (int64_t) ms.ullTotalPageFile >> 20);
    st->print("(AvailPageFile size " INT64_FORMAT "M)",
             (int64_t) ms.ullAvailPageFile >> 20);

    // on 32bit Total/AvailVirtual are interesting (show us how close we get to 2-4 GB per process borders)
#if defined(_M_IX86)
    st->print(", user-mode portion of virtual address-space " INT64_FORMAT "M ",
             (int64_t) ms.ullTotalVirtual >> 20);
    st->print("(" INT64_FORMAT "M free)", (int64_t) ms.ullAvailVirtual >> 20);
#endif
  } else {
    st->print(", GlobalMemoryStatusEx did not succeed so we miss some memory values.");
  }

  // extended memory statistics for a process
  PROCESS_MEMORY_COUNTERS_EX pmex;
  ZeroMemory(&pmex, sizeof(PROCESS_MEMORY_COUNTERS_EX));
  pmex.cb = sizeof(pmex);
  int r2 = GetProcessMemoryInfo(GetCurrentProcess(), (PROCESS_MEMORY_COUNTERS*) &pmex, sizeof(pmex));

  if (r2 != 0) {
    st->print("\ncurrent process WorkingSet (physical memory assigned to process): " INT64_FORMAT "M, ",
             (int64_t) pmex.WorkingSetSize >> 20);
    st->print("peak: " INT64_FORMAT "M\n", (int64_t) pmex.PeakWorkingSetSize >> 20);

    st->print("current process commit charge (\"private bytes\"): " INT64_FORMAT "M, ",
             (int64_t) pmex.PrivateUsage >> 20);
    st->print("peak: " INT64_FORMAT "M", (int64_t) pmex.PeakPagefileUsage >> 20);
  } else {
    st->print("\nGetProcessMemoryInfo did not succeed so we miss some memory values.");
  }

  st->cr();
}

bool os::signal_sent_by_kill(const void* siginfo) {
  // TODO: Is this possible?
  return false;
}

void os::print_siginfo(outputStream *st, const void* siginfo) {
  const EXCEPTION_RECORD* const er = (EXCEPTION_RECORD*)siginfo;
  st->print("siginfo:");

  char tmp[64];
  if (os::exception_name(er->ExceptionCode, tmp, sizeof(tmp)) == NULL) {
    strcpy(tmp, "EXCEPTION_??");
  }
  st->print(" %s (0x%x)", tmp, er->ExceptionCode);

  if ((er->ExceptionCode == EXCEPTION_ACCESS_VIOLATION ||
       er->ExceptionCode == EXCEPTION_IN_PAGE_ERROR) &&
       er->NumberParameters >= 2) {
    switch (er->ExceptionInformation[0]) {
    case 0: st->print(", reading address"); break;
    case 1: st->print(", writing address"); break;
    case 8: st->print(", data execution prevention violation at address"); break;
    default: st->print(", ExceptionInformation=" INTPTR_FORMAT,
                       er->ExceptionInformation[0]);
    }
    st->print(" " INTPTR_FORMAT, er->ExceptionInformation[1]);
  } else {
    int num = er->NumberParameters;
    if (num > 0) {
      st->print(", ExceptionInformation=");
      for (int i = 0; i < num; i++) {
        st->print(INTPTR_FORMAT " ", er->ExceptionInformation[i]);
      }
    }
  }
  st->cr();
}

bool os::signal_thread(Thread* thread, int sig, const char* reason) {
  // TODO: Can we kill thread?
  return false;
}

void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
  // do nothing
}

static char saved_jvm_path[MAX_PATH] = {0};

// Find the full path to the current module, jvm.dll
void os::jvm_path(char *buf, jint buflen) {
  // Error checking.
  if (buflen < MAX_PATH) {
    assert(false, "must use a large-enough buffer");
    buf[0] = '\0';
    return;
  }
  // Lazy resolve the path to current module.
  if (saved_jvm_path[0] != 0) {
    strcpy(buf, saved_jvm_path);
    return;
  }

  buf[0] = '\0';
  if (Arguments::sun_java_launcher_is_altjvm()) {
    // Support for the java launcher's '-XXaltjvm=<path>' option. Check
    // for a JAVA_HOME environment variable and fix up the path so it
    // looks like jvm.dll is installed there (append a fake suffix
    // hotspot/jvm.dll).
    char* java_home_var = ::getenv("JAVA_HOME");
    if (java_home_var != NULL && java_home_var[0] != 0 &&
        strlen(java_home_var) < (size_t)buflen) {
      strncpy(buf, java_home_var, buflen);

      // determine if this is a legacy image or modules image
      // modules image doesn't have "jre" subdirectory
      size_t len = strlen(buf);
      char* jrebin_p = buf + len;
      jio_snprintf(jrebin_p, buflen-len, "\\jre\\bin\\");
      if (0 != _access(buf, 0)) {
        jio_snprintf(jrebin_p, buflen-len, "\\bin\\");
      }
      len = strlen(buf);
--> --------------------

--> maximum size reached

--> --------------------

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