src/platform-win32.cc

root/src/platform-win32.cc

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DEFINITIONS

This source file includes following definitions.
strncasecmp
MemoryBarrier
localtime_s
fopen_s
_vsnprintf_s
strncpy_s
random
MaxVirtualMemory
ceiling
MemCopy
init_modulo_function
modulo
modulo
UNARY_MATH_FUNCTION
ft
ToJSTime
GuessTimezoneNameFromBias
TzSet
Diff
SetToCurrentTime
LocalOffset
InDST
DaylightSavingsOffset
LocalTimezone
PostSetUp
GetUserTime
TimeCurrentMillis
Ticks
LocalTimezone
LocalTimeOffset
DaylightSavingsOffset
GetLastError
GetCurrentProcessId
HasConsole
VPrintHelper
FOpen
Remove
OpenTemporaryFile
Print
VPrint
FPrint
VFPrint
PrintError
VPrintError
SNPrintF
VSNPrintF
StrChr
StrNCpy
UpdateAllocatedSpaceLimits
IsOutsideAllocatedSpace
GetPageSize
AllocateAlignment
GetRandomAddr
RandomizedVirtualAlloc
Allocate
Free
CommitPageSize
ProtectCode
Guard
Sleep
Abort
DebugBreak
size_
memory
size
open
create
DBGHELP_FUNCTION_LIST
LoadSymbols
LogSharedLibraryAddresses
SignalCodeMovingGC
StackWalk
LogSharedLibraryAddresses
SignalCodeMovingGC
StackWalk
CpuFeaturesImpliedByPlatform
nan_value
ActivationFrameAlignment
ReleaseStore
size_
size_
size_
IsReserved
Reset
Commit
Uncommit
ReserveRegion
CommitRegion
Guard
UncommitRegion
ReleaseRegion
ThreadEntry
PlatformData
set_name
Start
Join
CreateThreadLocalKey
DeleteThreadLocalKey
GetThreadLocal
SetThreadLocal
YieldCPU
Lock
Unlock
TryLock
CreateMutex
Wait
Wait
Signal
CreateSemaphore
IsValid
Bind
Listen
Accept
Connect
Shutdown
Send
Receive
SetReuseAddress
SetUp
LastError
HToN
NToH
HToN
NToH
CreateSocket
PlatformData
PlatformData
profiled_thread
interval_
SetUp
TearDown
AddActiveSampler
RemoveActiveSampler
Run
DoCpuProfile
DoRuntimeProfile
SampleContext
SetUp
TearDown
samples_taken_
Start
Stop
// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// Platform specific code for Win32.

#define V8_WIN32_HEADERS_FULL
#include "win32-headers.h"

#include "v8.h"

#include "codegen.h"
#include "platform.h"
#include "vm-state-inl.h"

#ifdef _MSC_VER

// Case-insensitive bounded string comparisons. Use stricmp() on Win32. Usually
// defined in strings.h.
int strncasecmp(const char* s1, const char* s2, int n) {
  return _strnicmp(s1, s2, n);
}

#endif  // _MSC_VER


// Extra functions for MinGW. Most of these are the _s functions which are in
// the Microsoft Visual Studio C++ CRT.
#ifdef __MINGW32__


#ifndef __MINGW64_VERSION_MAJOR

#define _TRUNCATE 0
#define STRUNCATE 80

inline void MemoryBarrier() {
  int barrier = 0;
  __asm__ __volatile__("xchgl %%eax,%0 ":"=r" (barrier));
}

#endif  // __MINGW64_VERSION_MAJOR


#ifndef MINGW_HAS_SECURE_API

int localtime_s(tm* out_tm, const time_t* time) {
  tm* posix_local_time_struct = localtime(time);
  if (posix_local_time_struct == NULL) return 1;
  *out_tm = *posix_local_time_struct;
  return 0;
}


int fopen_s(FILE** pFile, const char* filename, const char* mode) {
  *pFile = fopen(filename, mode);
  return *pFile != NULL ? 0 : 1;
}

int _vsnprintf_s(char* buffer, size_t sizeOfBuffer, size_t count,
                 const char* format, va_list argptr) {
  ASSERT(count == _TRUNCATE);
  return _vsnprintf(buffer, sizeOfBuffer, format, argptr);
}


int strncpy_s(char* dest, size_t dest_size, const char* source, size_t count) {
  CHECK(source != NULL);
  CHECK(dest != NULL);
  CHECK_GT(dest_size, 0);

  if (count == _TRUNCATE) {
    while (dest_size > 0 && *source != 0) {
      *(dest++) = *(source++);
      --dest_size;
    }
    if (dest_size == 0) {
      *(dest - 1) = 0;
      return STRUNCATE;
    }
  } else {
    while (dest_size > 0 && count > 0 && *source != 0) {
      *(dest++) = *(source++);
      --dest_size;
      --count;
    }
  }
  CHECK_GT(dest_size, 0);
  *dest = 0;
  return 0;
}

#endif  // MINGW_HAS_SECURE_API

#endif  // __MINGW32__

// Generate a pseudo-random number in the range 0-2^31-1. Usually
// defined in stdlib.h. Missing in both Microsoft Visual Studio C++ and MinGW.
int random() {
  return rand();
}


namespace v8 {
namespace internal {

intptr_t OS::MaxVirtualMemory() {
  return 0;
}


double ceiling(double x) {
  return ceil(x);
}


static Mutex* limit_mutex = NULL;

#if defined(V8_TARGET_ARCH_IA32)
static OS::MemCopyFunction memcopy_function = NULL;
// Defined in codegen-ia32.cc.
OS::MemCopyFunction CreateMemCopyFunction();

// Copy memory area to disjoint memory area.
void OS::MemCopy(void* dest, const void* src, size_t size) {
  // Note: here we rely on dependent reads being ordered. This is true
  // on all architectures we currently support.
  (*memcopy_function)(dest, src, size);
#ifdef DEBUG
  CHECK_EQ(0, memcmp(dest, src, size));
#endif
}
#endif  // V8_TARGET_ARCH_IA32

#ifdef _WIN64
typedef double (*ModuloFunction)(double, double);
static ModuloFunction modulo_function = NULL;
// Defined in codegen-x64.cc.
ModuloFunction CreateModuloFunction();

void init_modulo_function() {
  modulo_function = CreateModuloFunction();
}

double modulo(double x, double y) {
  // Note: here we rely on dependent reads being ordered. This is true
  // on all architectures we currently support.
  return (*modulo_function)(x, y);
}
#else  // Win32

double modulo(double x, double y) {
  // Workaround MS fmod bugs. ECMA-262 says:
  // dividend is finite and divisor is an infinity => result equals dividend
  // dividend is a zero and divisor is nonzero finite => result equals dividend
  if (!(isfinite(x) && (!isfinite(y) && !isnan(y))) &&
      !(x == 0 && (y != 0 && isfinite(y)))) {
    x = fmod(x, y);
  }
  return x;
}

#endif  // _WIN64


#define UNARY_MATH_FUNCTION(name, generator)             \
static UnaryMathFunction fast_##name##_function = NULL;  \
void init_fast_##name##_function() {                     \
  fast_##name##_function = generator;                    \
}                                                        \
double fast_##name(double x) {                           \
  return (*fast_##name##_function)(x);                   \
}

UNARY_MATH_FUNCTION(sin, CreateTranscendentalFunction(TranscendentalCache::SIN))
UNARY_MATH_FUNCTION(cos, CreateTranscendentalFunction(TranscendentalCache::COS))
UNARY_MATH_FUNCTION(tan, CreateTranscendentalFunction(TranscendentalCache::TAN))
UNARY_MATH_FUNCTION(log, CreateTranscendentalFunction(TranscendentalCache::LOG))
UNARY_MATH_FUNCTION(sqrt, CreateSqrtFunction())

#undef MATH_FUNCTION


void MathSetup() {
#ifdef _WIN64
  init_modulo_function();
#endif
  init_fast_sin_function();
  init_fast_cos_function();
  init_fast_tan_function();
  init_fast_log_function();
  init_fast_sqrt_function();
}


// ----------------------------------------------------------------------------
// The Time class represents time on win32. A timestamp is represented as
// a 64-bit integer in 100 nanoseconds since January 1, 1601 (UTC). JavaScript
// timestamps are represented as a doubles in milliseconds since 00:00:00 UTC,
// January 1, 1970.

class Time {
 public:
  // Constructors.
  Time();
  explicit Time(double jstime);
  Time(int year, int mon, int day, int hour, int min, int sec);

  // Convert timestamp to JavaScript representation.
  double ToJSTime();

  // Set timestamp to current time.
  void SetToCurrentTime();

  // Returns the local timezone offset in milliseconds east of UTC. This is
  // the number of milliseconds you must add to UTC to get local time, i.e.
  // LocalOffset(CET) = 3600000 and LocalOffset(PST) = -28800000. This
  // routine also takes into account whether daylight saving is effect
  // at the time.
  int64_t LocalOffset();

  // Returns the daylight savings time offset for the time in milliseconds.
  int64_t DaylightSavingsOffset();

  // Returns a string identifying the current timezone for the
  // timestamp taking into account daylight saving.
  char* LocalTimezone();

 private:
  // Constants for time conversion.
  static const int64_t kTimeEpoc = 116444736000000000LL;
  static const int64_t kTimeScaler = 10000;
  static const int64_t kMsPerMinute = 60000;

  // Constants for timezone information.
  static const int kTzNameSize = 128;
  static const bool kShortTzNames = false;

  // Timezone information. We need to have static buffers for the
  // timezone names because we return pointers to these in
  // LocalTimezone().
  static bool tz_initialized_;
  static TIME_ZONE_INFORMATION tzinfo_;
  static char std_tz_name_[kTzNameSize];
  static char dst_tz_name_[kTzNameSize];

  // Initialize the timezone information (if not already done).
  static void TzSet();

  // Guess the name of the timezone from the bias.
  static const char* GuessTimezoneNameFromBias(int bias);

  // Return whether or not daylight savings time is in effect at this time.
  bool InDST();

  // Return the difference (in milliseconds) between this timestamp and
  // another timestamp.
  int64_t Diff(Time* other);

  // Accessor for FILETIME representation.
  FILETIME& ft() { return time_.ft_; }

  // Accessor for integer representation.
  int64_t& t() { return time_.t_; }

  // Although win32 uses 64-bit integers for representing timestamps,
  // these are packed into a FILETIME structure. The FILETIME structure
  // is just a struct representing a 64-bit integer. The TimeStamp union
  // allows access to both a FILETIME and an integer representation of
  // the timestamp.
  union TimeStamp {
    FILETIME ft_;
    int64_t t_;
  };

  TimeStamp time_;
};

// Static variables.
bool Time::tz_initialized_ = false;
TIME_ZONE_INFORMATION Time::tzinfo_;
char Time::std_tz_name_[kTzNameSize];
char Time::dst_tz_name_[kTzNameSize];


// Initialize timestamp to start of epoc.
Time::Time() {
  t() = 0;
}


// Initialize timestamp from a JavaScript timestamp.
Time::Time(double jstime) {
  t() = static_cast<int64_t>(jstime) * kTimeScaler + kTimeEpoc;
}


// Initialize timestamp from date/time components.
Time::Time(int year, int mon, int day, int hour, int min, int sec) {
  SYSTEMTIME st;
  st.wYear = year;
  st.wMonth = mon;
  st.wDay = day;
  st.wHour = hour;
  st.wMinute = min;
  st.wSecond = sec;
  st.wMilliseconds = 0;
  SystemTimeToFileTime(&st, &ft());
}


// Convert timestamp to JavaScript timestamp.
double Time::ToJSTime() {
  return static_cast<double>((t() - kTimeEpoc) / kTimeScaler);
}


// Guess the name of the timezone from the bias.
// The guess is very biased towards the northern hemisphere.
const char* Time::GuessTimezoneNameFromBias(int bias) {
  static const int kHour = 60;
  switch (-bias) {
    case -9*kHour: return "Alaska";
    case -8*kHour: return "Pacific";
    case -7*kHour: return "Mountain";
    case -6*kHour: return "Central";
    case -5*kHour: return "Eastern";
    case -4*kHour: return "Atlantic";
    case  0*kHour: return "GMT";
    case +1*kHour: return "Central Europe";
    case +2*kHour: return "Eastern Europe";
    case +3*kHour: return "Russia";
    case +5*kHour + 30: return "India";
    case +8*kHour: return "China";
    case +9*kHour: return "Japan";
    case +12*kHour: return "New Zealand";
    default: return "Local";
  }
}


// Initialize timezone information. The timezone information is obtained from
// windows. If we cannot get the timezone information we fall back to CET.
// Please notice that this code is not thread-safe.
void Time::TzSet() {
  // Just return if timezone information has already been initialized.
  if (tz_initialized_) return;

  // Initialize POSIX time zone data.
  _tzset();
  // Obtain timezone information from operating system.
  memset(&tzinfo_, 0, sizeof(tzinfo_));
  if (GetTimeZoneInformation(&tzinfo_) == TIME_ZONE_ID_INVALID) {
    // If we cannot get timezone information we fall back to CET.
    tzinfo_.Bias = -60;
    tzinfo_.StandardDate.wMonth = 10;
    tzinfo_.StandardDate.wDay = 5;
    tzinfo_.StandardDate.wHour = 3;
    tzinfo_.StandardBias = 0;
    tzinfo_.DaylightDate.wMonth = 3;
    tzinfo_.DaylightDate.wDay = 5;
    tzinfo_.DaylightDate.wHour = 2;
    tzinfo_.DaylightBias = -60;
  }

  // Make standard and DST timezone names.
  WideCharToMultiByte(CP_UTF8, 0, tzinfo_.StandardName, -1,
                      std_tz_name_, kTzNameSize, NULL, NULL);
  std_tz_name_[kTzNameSize - 1] = '\0';
  WideCharToMultiByte(CP_UTF8, 0, tzinfo_.DaylightName, -1,
                      dst_tz_name_, kTzNameSize, NULL, NULL);
  dst_tz_name_[kTzNameSize - 1] = '\0';

  // If OS returned empty string or resource id (like "@tzres.dll,-211")
  // simply guess the name from the UTC bias of the timezone.
  // To properly resolve the resource identifier requires a library load,
  // which is not possible in a sandbox.
  if (std_tz_name_[0] == '\0' || std_tz_name_[0] == '@') {
    OS::SNPrintF(Vector<char>(std_tz_name_, kTzNameSize - 1),
                 "%s Standard Time",
                 GuessTimezoneNameFromBias(tzinfo_.Bias));
  }
  if (dst_tz_name_[0] == '\0' || dst_tz_name_[0] == '@') {
    OS::SNPrintF(Vector<char>(dst_tz_name_, kTzNameSize - 1),
                 "%s Daylight Time",
                 GuessTimezoneNameFromBias(tzinfo_.Bias));
  }

  // Timezone information initialized.
  tz_initialized_ = true;
}


// Return the difference in milliseconds between this and another timestamp.
int64_t Time::Diff(Time* other) {
  return (t() - other->t()) / kTimeScaler;
}


// Set timestamp to current time.
void Time::SetToCurrentTime() {
  // The default GetSystemTimeAsFileTime has a ~15.5ms resolution.
  // Because we're fast, we like fast timers which have at least a
  // 1ms resolution.
  //
  // timeGetTime() provides 1ms granularity when combined with
  // timeBeginPeriod().  If the host application for v8 wants fast
  // timers, it can use timeBeginPeriod to increase the resolution.
  //
  // Using timeGetTime() has a drawback because it is a 32bit value
  // and hence rolls-over every ~49days.
  //
  // To use the clock, we use GetSystemTimeAsFileTime as our base;
  // and then use timeGetTime to extrapolate current time from the
  // start time.  To deal with rollovers, we resync the clock
  // any time when more than kMaxClockElapsedTime has passed or
  // whenever timeGetTime creates a rollover.

  static bool initialized = false;
  static TimeStamp init_time;
  static DWORD init_ticks;
  static const int64_t kHundredNanosecondsPerSecond = 10000000;
  static const int64_t kMaxClockElapsedTime =
      60*kHundredNanosecondsPerSecond;  // 1 minute

  // If we are uninitialized, we need to resync the clock.
  bool needs_resync = !initialized;

  // Get the current time.
  TimeStamp time_now;
  GetSystemTimeAsFileTime(&time_now.ft_);
  DWORD ticks_now = timeGetTime();

  // Check if we need to resync due to clock rollover.
  needs_resync |= ticks_now < init_ticks;

  // Check if we need to resync due to elapsed time.
  needs_resync |= (time_now.t_ - init_time.t_) > kMaxClockElapsedTime;

  // Check if we need to resync due to backwards time change.
  needs_resync |= time_now.t_ < init_time.t_;

  // Resync the clock if necessary.
  if (needs_resync) {
    GetSystemTimeAsFileTime(&init_time.ft_);
    init_ticks = ticks_now = timeGetTime();
    initialized = true;
  }

  // Finally, compute the actual time.  Why is this so hard.
  DWORD elapsed = ticks_now - init_ticks;
  this->time_.t_ = init_time.t_ + (static_cast<int64_t>(elapsed) * 10000);
}


// Return the local timezone offset in milliseconds east of UTC. This
// takes into account whether daylight saving is in effect at the time.
// Only times in the 32-bit Unix range may be passed to this function.
// Also, adding the time-zone offset to the input must not overflow.
// The function EquivalentTime() in date.js guarantees this.
int64_t Time::LocalOffset() {
  // Initialize timezone information, if needed.
  TzSet();

  Time rounded_to_second(*this);
  rounded_to_second.t() = rounded_to_second.t() / 1000 / kTimeScaler *
      1000 * kTimeScaler;
  // Convert to local time using POSIX localtime function.
  // Windows XP Service Pack 3 made SystemTimeToTzSpecificLocalTime()
  // very slow.  Other browsers use localtime().

  // Convert from JavaScript milliseconds past 1/1/1970 0:00:00 to
  // POSIX seconds past 1/1/1970 0:00:00.
  double unchecked_posix_time = rounded_to_second.ToJSTime() / 1000;
  if (unchecked_posix_time > INT_MAX || unchecked_posix_time < 0) {
    return 0;
  }
  // Because _USE_32BIT_TIME_T is defined, time_t is a 32-bit int.
  time_t posix_time = static_cast<time_t>(unchecked_posix_time);

  // Convert to local time, as struct with fields for day, hour, year, etc.
  tm posix_local_time_struct;
  if (localtime_s(&posix_local_time_struct, &posix_time)) return 0;

  if (posix_local_time_struct.tm_isdst > 0) {
    return (tzinfo_.Bias + tzinfo_.DaylightBias) * -kMsPerMinute;
  } else if (posix_local_time_struct.tm_isdst == 0) {
    return (tzinfo_.Bias + tzinfo_.StandardBias) * -kMsPerMinute;
  } else {
    return tzinfo_.Bias * -kMsPerMinute;
  }
}


// Return whether or not daylight savings time is in effect at this time.
bool Time::InDST() {
  // Initialize timezone information, if needed.
  TzSet();

  // Determine if DST is in effect at the specified time.
  bool in_dst = false;
  if (tzinfo_.StandardDate.wMonth != 0 || tzinfo_.DaylightDate.wMonth != 0) {
    // Get the local timezone offset for the timestamp in milliseconds.
    int64_t offset = LocalOffset();

    // Compute the offset for DST. The bias parameters in the timezone info
    // are specified in minutes. These must be converted to milliseconds.
    int64_t dstofs = -(tzinfo_.Bias + tzinfo_.DaylightBias) * kMsPerMinute;

    // If the local time offset equals the timezone bias plus the daylight
    // bias then DST is in effect.
    in_dst = offset == dstofs;
  }

  return in_dst;
}


// Return the daylight savings time offset for this time.
int64_t Time::DaylightSavingsOffset() {
  return InDST() ? 60 * kMsPerMinute : 0;
}


// Returns a string identifying the current timezone for the
// timestamp taking into account daylight saving.
char* Time::LocalTimezone() {
  // Return the standard or DST time zone name based on whether daylight
  // saving is in effect at the given time.
  return InDST() ? dst_tz_name_ : std_tz_name_;
}


void OS::PostSetUp() {
  // Math functions depend on CPU features therefore they are initialized after
  // CPU.
  MathSetup();
#if defined(V8_TARGET_ARCH_IA32)
  memcopy_function = CreateMemCopyFunction();
#endif
}


// Returns the accumulated user time for thread.
int OS::GetUserTime(uint32_t* secs,  uint32_t* usecs) {
  FILETIME dummy;
  uint64_t usertime;

  // Get the amount of time that the thread has executed in user mode.
  if (!GetThreadTimes(GetCurrentThread(), &dummy, &dummy, &dummy,
                      reinterpret_cast<FILETIME*>(&usertime))) return -1;

  // Adjust the resolution to micro-seconds.
  usertime /= 10;

  // Convert to seconds and microseconds
  *secs = static_cast<uint32_t>(usertime / 1000000);
  *usecs = static_cast<uint32_t>(usertime % 1000000);
  return 0;
}


// Returns current time as the number of milliseconds since
// 00:00:00 UTC, January 1, 1970.
double OS::TimeCurrentMillis() {
  Time t;
  t.SetToCurrentTime();
  return t.ToJSTime();
}

// Returns the tickcounter based on timeGetTime.
int64_t OS::Ticks() {
  return timeGetTime() * 1000;  // Convert to microseconds.
}


// Returns a string identifying the current timezone taking into
// account daylight saving.
const char* OS::LocalTimezone(double time) {
  return Time(time).LocalTimezone();
}


// Returns the local time offset in milliseconds east of UTC without
// taking daylight savings time into account.
double OS::LocalTimeOffset() {
  // Use current time, rounded to the millisecond.
  Time t(TimeCurrentMillis());
  // Time::LocalOffset inlcudes any daylight savings offset, so subtract it.
  return static_cast<double>(t.LocalOffset() - t.DaylightSavingsOffset());
}


// Returns the daylight savings offset in milliseconds for the given
// time.
double OS::DaylightSavingsOffset(double time) {
  int64_t offset = Time(time).DaylightSavingsOffset();
  return static_cast<double>(offset);
}


int OS::GetLastError() {
  return ::GetLastError();
}


int OS::GetCurrentProcessId() {
  return static_cast<int>(::GetCurrentProcessId());
}


// ----------------------------------------------------------------------------
// Win32 console output.
//
// If a Win32 application is linked as a console application it has a normal
// standard output and standard error. In this case normal printf works fine
// for output. However, if the application is linked as a GUI application,
// the process doesn't have a console, and therefore (debugging) output is lost.
// This is the case if we are embedded in a windows program (like a browser).
// In order to be able to get debug output in this case the the debugging
// facility using OutputDebugString. This output goes to the active debugger
// for the process (if any). Else the output can be monitored using DBMON.EXE.

enum OutputMode {
  UNKNOWN,  // Output method has not yet been determined.
  CONSOLE,  // Output is written to stdout.
  ODS       // Output is written to debug facility.
};

static OutputMode output_mode = UNKNOWN;  // Current output mode.


// Determine if the process has a console for output.
static bool HasConsole() {
  // Only check the first time. Eventual race conditions are not a problem,
  // because all threads will eventually determine the same mode.
  if (output_mode == UNKNOWN) {
    // We cannot just check that the standard output is attached to a console
    // because this would fail if output is redirected to a file. Therefore we
    // say that a process does not have an output console if either the
    // standard output handle is invalid or its file type is unknown.
    if (GetStdHandle(STD_OUTPUT_HANDLE) != INVALID_HANDLE_VALUE &&
        GetFileType(GetStdHandle(STD_OUTPUT_HANDLE)) != FILE_TYPE_UNKNOWN)
      output_mode = CONSOLE;
    else
      output_mode = ODS;
  }
  return output_mode == CONSOLE;
}


static void VPrintHelper(FILE* stream, const char* format, va_list args) {
  if (HasConsole()) {
    vfprintf(stream, format, args);
  } else {
    // It is important to use safe print here in order to avoid
    // overflowing the buffer. We might truncate the output, but this
    // does not crash.
    EmbeddedVector<char, 4096> buffer;
    OS::VSNPrintF(buffer, format, args);
    OutputDebugStringA(buffer.start());
  }
}


FILE* OS::FOpen(const char* path, const char* mode) {
  FILE* result;
  if (fopen_s(&result, path, mode) == 0) {
    return result;
  } else {
    return NULL;
  }
}


bool OS::Remove(const char* path) {
  return (DeleteFileA(path) != 0);
}


FILE* OS::OpenTemporaryFile() {
  // tmpfile_s tries to use the root dir, don't use it.
  char tempPathBuffer[MAX_PATH];
  DWORD path_result = 0;
  path_result = GetTempPathA(MAX_PATH, tempPathBuffer);
  if (path_result > MAX_PATH || path_result == 0) return NULL;
  UINT name_result = 0;
  char tempNameBuffer[MAX_PATH];
  name_result = GetTempFileNameA(tempPathBuffer, "", 0, tempNameBuffer);
  if (name_result == 0) return NULL;
  FILE* result = FOpen(tempNameBuffer, "w+");  // Same mode as tmpfile uses.
  if (result != NULL) {
    Remove(tempNameBuffer);  // Delete on close.
  }
  return result;
}


// Open log file in binary mode to avoid /n -> /r/n conversion.
const char* const OS::LogFileOpenMode = "wb";


// Print (debug) message to console.
void OS::Print(const char* format, ...) {
  va_list args;
  va_start(args, format);
  VPrint(format, args);
  va_end(args);
}


void OS::VPrint(const char* format, va_list args) {
  VPrintHelper(stdout, format, args);
}


void OS::FPrint(FILE* out, const char* format, ...) {
  va_list args;
  va_start(args, format);
  VFPrint(out, format, args);
  va_end(args);
}


void OS::VFPrint(FILE* out, const char* format, va_list args) {
  VPrintHelper(out, format, args);
}


// Print error message to console.
void OS::PrintError(const char* format, ...) {
  va_list args;
  va_start(args, format);
  VPrintError(format, args);
  va_end(args);
}


void OS::VPrintError(const char* format, va_list args) {
  VPrintHelper(stderr, format, args);
}


int OS::SNPrintF(Vector<char> str, const char* format, ...) {
  va_list args;
  va_start(args, format);
  int result = VSNPrintF(str, format, args);
  va_end(args);
  return result;
}


int OS::VSNPrintF(Vector<char> str, const char* format, va_list args) {
  int n = _vsnprintf_s(str.start(), str.length(), _TRUNCATE, format, args);
  // Make sure to zero-terminate the string if the output was
  // truncated or if there was an error.
  if (n < 0 || n >= str.length()) {
    if (str.length() > 0)
      str[str.length() - 1] = '\0';
    return -1;
  } else {
    return n;
  }
}


char* OS::StrChr(char* str, int c) {
  return const_cast<char*>(strchr(str, c));
}


void OS::StrNCpy(Vector<char> dest, const char* src, size_t n) {
  // Use _TRUNCATE or strncpy_s crashes (by design) if buffer is too small.
  size_t buffer_size = static_cast<size_t>(dest.length());
  if (n + 1 > buffer_size)  // count for trailing '\0'
    n = _TRUNCATE;
  int result = strncpy_s(dest.start(), dest.length(), src, n);
  USE(result);
  ASSERT(result == 0 || (n == _TRUNCATE && result == STRUNCATE));
}


// We keep the lowest and highest addresses mapped as a quick way of
// determining that pointers are outside the heap (used mostly in assertions
// and verification).  The estimate is conservative, i.e., not all addresses in
// 'allocated' space are actually allocated to our heap.  The range is
// [lowest, highest), inclusive on the low and and exclusive on the high end.
static void* lowest_ever_allocated = reinterpret_cast<void*>(-1);
static void* highest_ever_allocated = reinterpret_cast<void*>(0);


static void UpdateAllocatedSpaceLimits(void* address, int size) {
  ASSERT(limit_mutex != NULL);
  ScopedLock lock(limit_mutex);

  lowest_ever_allocated = Min(lowest_ever_allocated, address);
  highest_ever_allocated =
      Max(highest_ever_allocated,
          reinterpret_cast<void*>(reinterpret_cast<char*>(address) + size));
}


bool OS::IsOutsideAllocatedSpace(void* pointer) {
  if (pointer < lowest_ever_allocated || pointer >= highest_ever_allocated)
    return true;
  // Ask the Windows API
  if (IsBadWritePtr(pointer, 1))
    return true;
  return false;
}


// Get the system's page size used by VirtualAlloc() or the next power
// of two. The reason for always returning a power of two is that the
// rounding up in OS::Allocate expects that.
static size_t GetPageSize() {
  static size_t page_size = 0;
  if (page_size == 0) {
    SYSTEM_INFO info;
    GetSystemInfo(&info);
    page_size = RoundUpToPowerOf2(info.dwPageSize);
  }
  return page_size;
}


// The allocation alignment is the guaranteed alignment for
// VirtualAlloc'ed blocks of memory.
size_t OS::AllocateAlignment() {
  static size_t allocate_alignment = 0;
  if (allocate_alignment == 0) {
    SYSTEM_INFO info;
    GetSystemInfo(&info);
    allocate_alignment = info.dwAllocationGranularity;
  }
  return allocate_alignment;
}


static void* GetRandomAddr() {
  Isolate* isolate = Isolate::UncheckedCurrent();
  // Note that the current isolate isn't set up in a call path via
  // CpuFeatures::Probe. We don't care about randomization in this case because
  // the code page is immediately freed.
  if (isolate != NULL) {
    // The address range used to randomize RWX allocations in OS::Allocate
    // Try not to map pages into the default range that windows loads DLLs
    // Use a multiple of 64k to prevent committing unused memory.
    // Note: This does not guarantee RWX regions will be within the
    // range kAllocationRandomAddressMin to kAllocationRandomAddressMax
#ifdef V8_HOST_ARCH_64_BIT
    static const intptr_t kAllocationRandomAddressMin = 0x0000000080000000;
    static const intptr_t kAllocationRandomAddressMax = 0x000003FFFFFF0000;
#else
    static const intptr_t kAllocationRandomAddressMin = 0x04000000;
    static const intptr_t kAllocationRandomAddressMax = 0x3FFF0000;
#endif
    uintptr_t address = (V8::RandomPrivate(isolate) << kPageSizeBits)
        | kAllocationRandomAddressMin;
    address &= kAllocationRandomAddressMax;
    return reinterpret_cast<void *>(address);
  }
  return NULL;
}


static void* RandomizedVirtualAlloc(size_t size, int action, int protection) {
  LPVOID base = NULL;

  if (protection == PAGE_EXECUTE_READWRITE || protection == PAGE_NOACCESS) {
    // For exectutable pages try and randomize the allocation address
    for (size_t attempts = 0; base == NULL && attempts < 3; ++attempts) {
      base = VirtualAlloc(GetRandomAddr(), size, action, protection);
    }
  }

  // After three attempts give up and let the OS find an address to use.
  if (base == NULL) base = VirtualAlloc(NULL, size, action, protection);

  return base;
}


void* OS::Allocate(const size_t requested,
                   size_t* allocated,
                   bool is_executable) {
  // VirtualAlloc rounds allocated size to page size automatically.
  size_t msize = RoundUp(requested, static_cast<int>(GetPageSize()));

  // Windows XP SP2 allows Data Excution Prevention (DEP).
  int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;

  LPVOID mbase = RandomizedVirtualAlloc(msize,
                                        MEM_COMMIT | MEM_RESERVE,
                                        prot);

  if (mbase == NULL) {
    LOG(ISOLATE, StringEvent("OS::Allocate", "VirtualAlloc failed"));
    return NULL;
  }

  ASSERT(IsAligned(reinterpret_cast<size_t>(mbase), OS::AllocateAlignment()));

  *allocated = msize;
  UpdateAllocatedSpaceLimits(mbase, static_cast<int>(msize));
  return mbase;
}


void OS::Free(void* address, const size_t size) {
  // TODO(1240712): VirtualFree has a return value which is ignored here.
  VirtualFree(address, 0, MEM_RELEASE);
  USE(size);
}


intptr_t OS::CommitPageSize() {
  return 4096;
}


void OS::ProtectCode(void* address, const size_t size) {
  DWORD old_protect;
  VirtualProtect(address, size, PAGE_EXECUTE_READ, &old_protect);
}


void OS::Guard(void* address, const size_t size) {
  DWORD oldprotect;
  VirtualProtect(address, size, PAGE_READONLY | PAGE_GUARD, &oldprotect);
}


void OS::Sleep(int milliseconds) {
  ::Sleep(milliseconds);
}


void OS::Abort() {
  if (IsDebuggerPresent() || FLAG_break_on_abort) {
    DebugBreak();
  } else {
    // Make the MSVCRT do a silent abort.
    raise(SIGABRT);
  }
}


void OS::DebugBreak() {
#ifdef _MSC_VER
  __debugbreak();
#else
  ::DebugBreak();
#endif
}


class Win32MemoryMappedFile : public OS::MemoryMappedFile {
 public:
  Win32MemoryMappedFile(HANDLE file,
                        HANDLE file_mapping,
                        void* memory,
                        int size)
      : file_(file),
        file_mapping_(file_mapping),
        memory_(memory),
        size_(size) { }
  virtual ~Win32MemoryMappedFile();
  virtual void* memory() { return memory_; }
  virtual int size() { return size_; }
 private:
  HANDLE file_;
  HANDLE file_mapping_;
  void* memory_;
  int size_;
};


OS::MemoryMappedFile* OS::MemoryMappedFile::open(const char* name) {
  // Open a physical file
  HANDLE file = CreateFileA(name, GENERIC_READ | GENERIC_WRITE,
      FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
  if (file == INVALID_HANDLE_VALUE) return NULL;

  int size = static_cast<int>(GetFileSize(file, NULL));

  // Create a file mapping for the physical file
  HANDLE file_mapping = CreateFileMapping(file, NULL,
      PAGE_READWRITE, 0, static_cast<DWORD>(size), NULL);
  if (file_mapping == NULL) return NULL;

  // Map a view of the file into memory
  void* memory = MapViewOfFile(file_mapping, FILE_MAP_ALL_ACCESS, 0, 0, size);
  return new Win32MemoryMappedFile(file, file_mapping, memory, size);
}


OS::MemoryMappedFile* OS::MemoryMappedFile::create(const char* name, int size,
    void* initial) {
  // Open a physical file
  HANDLE file = CreateFileA(name, GENERIC_READ | GENERIC_WRITE,
      FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, 0, NULL);
  if (file == NULL) return NULL;
  // Create a file mapping for the physical file
  HANDLE file_mapping = CreateFileMapping(file, NULL,
      PAGE_READWRITE, 0, static_cast<DWORD>(size), NULL);
  if (file_mapping == NULL) return NULL;
  // Map a view of the file into memory
  void* memory = MapViewOfFile(file_mapping, FILE_MAP_ALL_ACCESS, 0, 0, size);
  if (memory) memmove(memory, initial, size);
  return new Win32MemoryMappedFile(file, file_mapping, memory, size);
}


Win32MemoryMappedFile::~Win32MemoryMappedFile() {
  if (memory_ != NULL)
    UnmapViewOfFile(memory_);
  CloseHandle(file_mapping_);
  CloseHandle(file_);
}


// The following code loads functions defined in DbhHelp.h and TlHelp32.h
// dynamically. This is to avoid being depending on dbghelp.dll and
// tlhelp32.dll when running (the functions in tlhelp32.dll have been moved to
// kernel32.dll at some point so loading functions defines in TlHelp32.h
// dynamically might not be necessary any more - for some versions of Windows?).

// Function pointers to functions dynamically loaded from dbghelp.dll.
#define DBGHELP_FUNCTION_LIST(V)  \
  V(SymInitialize)                \
  V(SymGetOptions)                \
  V(SymSetOptions)                \
  V(SymGetSearchPath)             \
  V(SymLoadModule64)              \
  V(StackWalk64)                  \
  V(SymGetSymFromAddr64)          \
  V(SymGetLineFromAddr64)         \
  V(SymFunctionTableAccess64)     \
  V(SymGetModuleBase64)

// Function pointers to functions dynamically loaded from dbghelp.dll.
#define TLHELP32_FUNCTION_LIST(V)  \
  V(CreateToolhelp32Snapshot)      \
  V(Module32FirstW)                \
  V(Module32NextW)

// Define the decoration to use for the type and variable name used for
// dynamically loaded DLL function..
#define DLL_FUNC_TYPE(name) _##name##_
#define DLL_FUNC_VAR(name) _##name

// Define the type for each dynamically loaded DLL function. The function
// definitions are copied from DbgHelp.h and TlHelp32.h. The IN and VOID macros
// from the Windows include files are redefined here to have the function
// definitions to be as close to the ones in the original .h files as possible.
#ifndef IN
#define IN
#endif
#ifndef VOID
#define VOID void
#endif

// DbgHelp isn't supported on MinGW yet
#ifndef __MINGW32__
// DbgHelp.h functions.
typedef BOOL (__stdcall *DLL_FUNC_TYPE(SymInitialize))(IN HANDLE hProcess,
                                                       IN PSTR UserSearchPath,
                                                       IN BOOL fInvadeProcess);
typedef DWORD (__stdcall *DLL_FUNC_TYPE(SymGetOptions))(VOID);
typedef DWORD (__stdcall *DLL_FUNC_TYPE(SymSetOptions))(IN DWORD SymOptions);
typedef BOOL (__stdcall *DLL_FUNC_TYPE(SymGetSearchPath))(
    IN HANDLE hProcess,
    OUT PSTR SearchPath,
    IN DWORD SearchPathLength);
typedef DWORD64 (__stdcall *DLL_FUNC_TYPE(SymLoadModule64))(
    IN HANDLE hProcess,
    IN HANDLE hFile,
    IN PSTR ImageName,
    IN PSTR ModuleName,
    IN DWORD64 BaseOfDll,
    IN DWORD SizeOfDll);
typedef BOOL (__stdcall *DLL_FUNC_TYPE(StackWalk64))(
    DWORD MachineType,
    HANDLE hProcess,
    HANDLE hThread,
    LPSTACKFRAME64 StackFrame,
    PVOID ContextRecord,
    PREAD_PROCESS_MEMORY_ROUTINE64 ReadMemoryRoutine,
    PFUNCTION_TABLE_ACCESS_ROUTINE64 FunctionTableAccessRoutine,
    PGET_MODULE_BASE_ROUTINE64 GetModuleBaseRoutine,
    PTRANSLATE_ADDRESS_ROUTINE64 TranslateAddress);
typedef BOOL (__stdcall *DLL_FUNC_TYPE(SymGetSymFromAddr64))(
    IN HANDLE hProcess,
    IN DWORD64 qwAddr,
    OUT PDWORD64 pdwDisplacement,
    OUT PIMAGEHLP_SYMBOL64 Symbol);
typedef BOOL (__stdcall *DLL_FUNC_TYPE(SymGetLineFromAddr64))(
    IN HANDLE hProcess,
    IN DWORD64 qwAddr,
    OUT PDWORD pdwDisplacement,
    OUT PIMAGEHLP_LINE64 Line64);
// DbgHelp.h typedefs. Implementation found in dbghelp.dll.
typedef PVOID (__stdcall *DLL_FUNC_TYPE(SymFunctionTableAccess64))(
    HANDLE hProcess,
    DWORD64 AddrBase);  // DbgHelp.h typedef PFUNCTION_TABLE_ACCESS_ROUTINE64
typedef DWORD64 (__stdcall *DLL_FUNC_TYPE(SymGetModuleBase64))(
    HANDLE hProcess,
    DWORD64 AddrBase);  // DbgHelp.h typedef PGET_MODULE_BASE_ROUTINE64

// TlHelp32.h functions.
typedef HANDLE (__stdcall *DLL_FUNC_TYPE(CreateToolhelp32Snapshot))(
    DWORD dwFlags,
    DWORD th32ProcessID);
typedef BOOL (__stdcall *DLL_FUNC_TYPE(Module32FirstW))(HANDLE hSnapshot,
                                                        LPMODULEENTRY32W lpme);
typedef BOOL (__stdcall *DLL_FUNC_TYPE(Module32NextW))(HANDLE hSnapshot,
                                                       LPMODULEENTRY32W lpme);

#undef IN
#undef VOID

// Declare a variable for each dynamically loaded DLL function.
#define DEF_DLL_FUNCTION(name) DLL_FUNC_TYPE(name) DLL_FUNC_VAR(name) = NULL;
DBGHELP_FUNCTION_LIST(DEF_DLL_FUNCTION)
TLHELP32_FUNCTION_LIST(DEF_DLL_FUNCTION)
#undef DEF_DLL_FUNCTION

// Load the functions. This function has a lot of "ugly" macros in order to
// keep down code duplication.

static bool LoadDbgHelpAndTlHelp32() {
  static bool dbghelp_loaded = false;

  if (dbghelp_loaded) return true;

  HMODULE module;

  // Load functions from the dbghelp.dll module.
  module = LoadLibrary(TEXT("dbghelp.dll"));
  if (module == NULL) {
    return false;
  }

#define LOAD_DLL_FUNC(name)                                                 \
  DLL_FUNC_VAR(name) =                                                      \
      reinterpret_cast<DLL_FUNC_TYPE(name)>(GetProcAddress(module, #name));

DBGHELP_FUNCTION_LIST(LOAD_DLL_FUNC)

#undef LOAD_DLL_FUNC

  // Load functions from the kernel32.dll module (the TlHelp32.h function used
  // to be in tlhelp32.dll but are now moved to kernel32.dll).
  module = LoadLibrary(TEXT("kernel32.dll"));
  if (module == NULL) {
    return false;
  }

#define LOAD_DLL_FUNC(name)                                                 \
  DLL_FUNC_VAR(name) =                                                      \
      reinterpret_cast<DLL_FUNC_TYPE(name)>(GetProcAddress(module, #name));

TLHELP32_FUNCTION_LIST(LOAD_DLL_FUNC)

#undef LOAD_DLL_FUNC

  // Check that all functions where loaded.
  bool result =
#define DLL_FUNC_LOADED(name) (DLL_FUNC_VAR(name) != NULL) &&

DBGHELP_FUNCTION_LIST(DLL_FUNC_LOADED)
TLHELP32_FUNCTION_LIST(DLL_FUNC_LOADED)

#undef DLL_FUNC_LOADED
  true;

  dbghelp_loaded = result;
  return result;
  // NOTE: The modules are never unloaded and will stay around until the
  // application is closed.
}


// Load the symbols for generating stack traces.
static bool LoadSymbols(HANDLE process_handle) {
  static bool symbols_loaded = false;

  if (symbols_loaded) return true;

  BOOL ok;

  // Initialize the symbol engine.
  ok = _SymInitialize(process_handle,  // hProcess
                      NULL,            // UserSearchPath
                      false);          // fInvadeProcess
  if (!ok) return false;

  DWORD options = _SymGetOptions();
  options |= SYMOPT_LOAD_LINES;
  options |= SYMOPT_FAIL_CRITICAL_ERRORS;
  options = _SymSetOptions(options);

  char buf[OS::kStackWalkMaxNameLen] = {0};
  ok = _SymGetSearchPath(process_handle, buf, OS::kStackWalkMaxNameLen);
  if (!ok) {
    int err = GetLastError();
    PrintF("%d\n", err);
    return false;
  }

  HANDLE snapshot = _CreateToolhelp32Snapshot(
      TH32CS_SNAPMODULE,       // dwFlags
      GetCurrentProcessId());  // th32ProcessId
  if (snapshot == INVALID_HANDLE_VALUE) return false;
  MODULEENTRY32W module_entry;
  module_entry.dwSize = sizeof(module_entry);  // Set the size of the structure.
  BOOL cont = _Module32FirstW(snapshot, &module_entry);
  while (cont) {
    DWORD64 base;
    // NOTE the SymLoadModule64 function has the peculiarity of accepting a
    // both unicode and ASCII strings even though the parameter is PSTR.
    base = _SymLoadModule64(
        process_handle,                                       // hProcess
        0,                                                    // hFile
        reinterpret_cast<PSTR>(module_entry.szExePath),       // ImageName
        reinterpret_cast<PSTR>(module_entry.szModule),        // ModuleName
        reinterpret_cast<DWORD64>(module_entry.modBaseAddr),  // BaseOfDll
        module_entry.modBaseSize);                            // SizeOfDll
    if (base == 0) {
      int err = GetLastError();
      if (err != ERROR_MOD_NOT_FOUND &&
          err != ERROR_INVALID_HANDLE) return false;
    }
    LOG(i::Isolate::Current(),
        SharedLibraryEvent(
            module_entry.szExePath,
            reinterpret_cast<unsigned int>(module_entry.modBaseAddr),
            reinterpret_cast<unsigned int>(module_entry.modBaseAddr +
                                           module_entry.modBaseSize)));
    cont = _Module32NextW(snapshot, &module_entry);
  }
  CloseHandle(snapshot);

  symbols_loaded = true;
  return true;
}


void OS::LogSharedLibraryAddresses() {
  // SharedLibraryEvents are logged when loading symbol information.
  // Only the shared libraries loaded at the time of the call to
  // LogSharedLibraryAddresses are logged.  DLLs loaded after
  // initialization are not accounted for.
  if (!LoadDbgHelpAndTlHelp32()) return;
  HANDLE process_handle = GetCurrentProcess();
  LoadSymbols(process_handle);
}


void OS::SignalCodeMovingGC() {
}


// Walk the stack using the facilities in dbghelp.dll and tlhelp32.dll

// Switch off warning 4748 (/GS can not protect parameters and local variables
// from local buffer overrun because optimizations are disabled in function) as
// it is triggered by the use of inline assembler.
#pragma warning(push)
#pragma warning(disable : 4748)
int OS::StackWalk(Vector<OS::StackFrame> frames) {
  BOOL ok;

  // Load the required functions from DLL's.
  if (!LoadDbgHelpAndTlHelp32()) return kStackWalkError;

  // Get the process and thread handles.
  HANDLE process_handle = GetCurrentProcess();
  HANDLE thread_handle = GetCurrentThread();

  // Read the symbols.
  if (!LoadSymbols(process_handle)) return kStackWalkError;

  // Capture current context.
  CONTEXT context;
  RtlCaptureContext(&context);

  // Initialize the stack walking
  STACKFRAME64 stack_frame;
  memset(&stack_frame, 0, sizeof(stack_frame));
#ifdef  _WIN64
  stack_frame.AddrPC.Offset = context.Rip;
  stack_frame.AddrFrame.Offset = context.Rbp;
  stack_frame.AddrStack.Offset = context.Rsp;
#else
  stack_frame.AddrPC.Offset = context.Eip;
  stack_frame.AddrFrame.Offset = context.Ebp;
  stack_frame.AddrStack.Offset = context.Esp;
#endif
  stack_frame.AddrPC.Mode = AddrModeFlat;
  stack_frame.AddrFrame.Mode = AddrModeFlat;
  stack_frame.AddrStack.Mode = AddrModeFlat;
  int frames_count = 0;

  // Collect stack frames.
  int frames_size = frames.length();
  while (frames_count < frames_size) {
    ok = _StackWalk64(
        IMAGE_FILE_MACHINE_I386,    // MachineType
        process_handle,             // hProcess
        thread_handle,              // hThread
        &stack_frame,               // StackFrame
        &context,                   // ContextRecord
        NULL,                       // ReadMemoryRoutine
        _SymFunctionTableAccess64,  // FunctionTableAccessRoutine
        _SymGetModuleBase64,        // GetModuleBaseRoutine
        NULL);                      // TranslateAddress
    if (!ok) break;

    // Store the address.
    ASSERT((stack_frame.AddrPC.Offset >> 32) == 0);  // 32-bit address.
    frames[frames_count].address =
        reinterpret_cast<void*>(stack_frame.AddrPC.Offset);

    // Try to locate a symbol for this frame.
    DWORD64 symbol_displacement;
    SmartArrayPointer<IMAGEHLP_SYMBOL64> symbol(
        NewArray<IMAGEHLP_SYMBOL64>(kStackWalkMaxNameLen));
    if (symbol.is_empty()) return kStackWalkError;  // Out of memory.
    memset(*symbol, 0, sizeof(IMAGEHLP_SYMBOL64) + kStackWalkMaxNameLen);
    (*symbol)->SizeOfStruct = sizeof(IMAGEHLP_SYMBOL64);
    (*symbol)->MaxNameLength = kStackWalkMaxNameLen;
    ok = _SymGetSymFromAddr64(process_handle,             // hProcess
                              stack_frame.AddrPC.Offset,  // Address
                              &symbol_displacement,       // Displacement
                              *symbol);                   // Symbol
    if (ok) {
      // Try to locate more source information for the symbol.
      IMAGEHLP_LINE64 Line;
      memset(&Line, 0, sizeof(Line));
      Line.SizeOfStruct = sizeof(Line);
      DWORD line_displacement;
      ok = _SymGetLineFromAddr64(
          process_handle,             // hProcess
          stack_frame.AddrPC.Offset,  // dwAddr
          &line_displacement,         // pdwDisplacement
          &Line);                     // Line
      // Format a text representation of the frame based on the information
      // available.
      if (ok) {
        SNPrintF(MutableCStrVector(frames[frames_count].text,
                                   kStackWalkMaxTextLen),
                 "%s %s:%d:%d",
                 (*symbol)->Name, Line.FileName, Line.LineNumber,
                 line_displacement);
      } else {
        SNPrintF(MutableCStrVector(frames[frames_count].text,
                                   kStackWalkMaxTextLen),
                 "%s",
                 (*symbol)->Name);
      }
      // Make sure line termination is in place.
      frames[frames_count].text[kStackWalkMaxTextLen - 1] = '\0';
    } else {
      // No text representation of this frame
      frames[frames_count].text[0] = '\0';

      // Continue if we are just missing a module (for non C/C++ frames a
      // module will never be found).
      int err = GetLastError();
      if (err != ERROR_MOD_NOT_FOUND) {
        break;
      }
    }

    frames_count++;
  }

  // Return the number of frames filled in.
  return frames_count;
}

// Restore warnings to previous settings.
#pragma warning(pop)

#else  // __MINGW32__
void OS::LogSharedLibraryAddresses() { }
void OS::SignalCodeMovingGC() { }
int OS::StackWalk(Vector<OS::StackFrame> frames) { return 0; }
#endif  // __MINGW32__


uint64_t OS::CpuFeaturesImpliedByPlatform() {
  return 0;  // Windows runs on anything.
}


double OS::nan_value() {
#ifdef _MSC_VER
  // Positive Quiet NaN with no payload (aka. Indeterminate) has all bits
  // in mask set, so value equals mask.
  static const __int64 nanval = kQuietNaNMask;
  return *reinterpret_cast<const double*>(&nanval);
#else  // _MSC_VER
  return NAN;
#endif  // _MSC_VER
}


int OS::ActivationFrameAlignment() {
#ifdef _WIN64
  return 16;  // Windows 64-bit ABI requires the stack to be 16-byte aligned.
#else
  return 8;  // Floating-point math runs faster with 8-byte alignment.
#endif
}


void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) {
  MemoryBarrier();
  *ptr = value;
}


VirtualMemory::VirtualMemory() : address_(NULL), size_(0) { }


VirtualMemory::VirtualMemory(size_t size)
    : address_(ReserveRegion(size)), size_(size) { }


VirtualMemory::VirtualMemory(size_t size, size_t alignment)
    : address_(NULL), size_(0) {
  ASSERT(IsAligned(alignment, static_cast<intptr_t>(OS::AllocateAlignment())));
  size_t request_size = RoundUp(size + alignment,
                                static_cast<intptr_t>(OS::AllocateAlignment()));
  void* address = ReserveRegion(request_size);
  if (address == NULL) return;
  Address base = RoundUp(static_cast<Address>(address), alignment);
  // Try reducing the size by freeing and then reallocating a specific area.
  bool result = ReleaseRegion(address, request_size);
  USE(result);
  ASSERT(result);
  address = VirtualAlloc(base, size, MEM_RESERVE, PAGE_NOACCESS);
  if (address != NULL) {
    request_size = size;
    ASSERT(base == static_cast<Address>(address));
  } else {
    // Resizing failed, just go with a bigger area.
    address = ReserveRegion(request_size);
    if (address == NULL) return;
  }
  address_ = address;
  size_ = request_size;
}


VirtualMemory::~VirtualMemory() {
  if (IsReserved()) {
    bool result = ReleaseRegion(address_, size_);
    ASSERT(result);
    USE(result);
  }
}


bool VirtualMemory::IsReserved() {
  return address_ != NULL;
}


void VirtualMemory::Reset() {
  address_ = NULL;
  size_ = 0;
}


bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) {
  if (CommitRegion(address, size, is_executable)) {
    UpdateAllocatedSpaceLimits(address, static_cast<int>(size));
    return true;
  }
  return false;
}


bool VirtualMemory::Uncommit(void* address, size_t size) {
  ASSERT(IsReserved());
  return UncommitRegion(address, size);
}


void* VirtualMemory::ReserveRegion(size_t size) {
  return RandomizedVirtualAlloc(size, MEM_RESERVE, PAGE_NOACCESS);
}


bool VirtualMemory::CommitRegion(void* base, size_t size, bool is_executable) {
  int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
  if (NULL == VirtualAlloc(base, size, MEM_COMMIT, prot)) {
    return false;
  }

  UpdateAllocatedSpaceLimits(base, static_cast<int>(size));
  return true;
}


bool VirtualMemory::Guard(void* address) {
  if (NULL == VirtualAlloc(address,
                           OS::CommitPageSize(),
                           MEM_COMMIT,
                           PAGE_READONLY | PAGE_GUARD)) {
    return false;
  }
  return true;
}


bool VirtualMemory::UncommitRegion(void* base, size_t size) {
  return VirtualFree(base, size, MEM_DECOMMIT) != 0;
}


bool VirtualMemory::ReleaseRegion(void* base, size_t size) {
  return VirtualFree(base, 0, MEM_RELEASE) != 0;
}


// ----------------------------------------------------------------------------
// Win32 thread support.

// Definition of invalid thread handle and id.
static const HANDLE kNoThread = INVALID_HANDLE_VALUE;

// Entry point for threads. The supplied argument is a pointer to the thread
// object. The entry function dispatches to the run method in the thread
// object. It is important that this function has __stdcall calling
// convention.
static unsigned int __stdcall ThreadEntry(void* arg) {
  Thread* thread = reinterpret_cast<Thread*>(arg);
  thread->Run();
  return 0;
}


class Thread::PlatformData : public Malloced {
 public:
  explicit PlatformData(HANDLE thread) : thread_(thread) {}
  HANDLE thread_;
  unsigned thread_id_;
};


// Initialize a Win32 thread object. The thread has an invalid thread
// handle until it is started.

Thread::Thread(const Options& options)
    : stack_size_(options.stack_size()) {
  data_ = new PlatformData(kNoThread);
  set_name(options.name());
}


void Thread::set_name(const char* name) {
  OS::StrNCpy(Vector<char>(name_, sizeof(name_)), name, strlen(name));
  name_[sizeof(name_) - 1] = '\0';
}


// Close our own handle for the thread.
Thread::~Thread() {
  if (data_->thread_ != kNoThread) CloseHandle(data_->thread_);
  delete data_;
}


// Create a new thread. It is important to use _beginthreadex() instead of
// the Win32 function CreateThread(), because the CreateThread() does not
// initialize thread specific structures in the C runtime library.
void Thread::Start() {
  data_->thread_ = reinterpret_cast<HANDLE>(
      _beginthreadex(NULL,
                     static_cast<unsigned>(stack_size_),
                     ThreadEntry,
                     this,
                     0,
                     &data_->thread_id_));
}


// Wait for thread to terminate.
void Thread::Join() {
  if (data_->thread_id_ != GetCurrentThreadId()) {
    WaitForSingleObject(data_->thread_, INFINITE);
  }
}


Thread::LocalStorageKey Thread::CreateThreadLocalKey() {
  DWORD result = TlsAlloc();
  ASSERT(result != TLS_OUT_OF_INDEXES);
  return static_cast<LocalStorageKey>(result);
}


void Thread::DeleteThreadLocalKey(LocalStorageKey key) {
  BOOL result = TlsFree(static_cast<DWORD>(key));
  USE(result);
  ASSERT(result);
}


void* Thread::GetThreadLocal(LocalStorageKey key) {
  return TlsGetValue(static_cast<DWORD>(key));
}


void Thread::SetThreadLocal(LocalStorageKey key, void* value) {
  BOOL result = TlsSetValue(static_cast<DWORD>(key), value);
  USE(result);
  ASSERT(result);
}



void Thread::YieldCPU() {
  Sleep(0);
}


// ----------------------------------------------------------------------------
// Win32 mutex support.
//
// On Win32 mutexes are implemented using CRITICAL_SECTION objects. These are
// faster than Win32 Mutex objects because they are implemented using user mode
// atomic instructions. Therefore we only do ring transitions if there is lock
// contention.

class Win32Mutex : public Mutex {
 public:
  Win32Mutex() { InitializeCriticalSection(&cs_); }

  virtual ~Win32Mutex() { DeleteCriticalSection(&cs_); }

  virtual int Lock() {
    EnterCriticalSection(&cs_);
    return 0;
  }

  virtual int Unlock() {
    LeaveCriticalSection(&cs_);
    return 0;
  }


  virtual bool TryLock() {
    // Returns non-zero if critical section is entered successfully entered.
    return TryEnterCriticalSection(&cs_);
  }

 private:
  CRITICAL_SECTION cs_;  // Critical section used for mutex
};


Mutex* OS::CreateMutex() {
  return new Win32Mutex();
}


// ----------------------------------------------------------------------------
// Win32 semaphore support.
//
// On Win32 semaphores are implemented using Win32 Semaphore objects. The
// semaphores are anonymous. Also, the semaphores are initialized to have
// no upper limit on count.


class Win32Semaphore : public Semaphore {
 public:
  explicit Win32Semaphore(int count) {
    sem = ::CreateSemaphoreA(NULL, count, 0x7fffffff, NULL);
  }

  ~Win32Semaphore() {
    CloseHandle(sem);
  }

  void Wait() {
    WaitForSingleObject(sem, INFINITE);
  }

  bool Wait(int timeout) {
    // Timeout in Windows API is in milliseconds.
    DWORD millis_timeout = timeout / 1000;
    return WaitForSingleObject(sem, millis_timeout) != WAIT_TIMEOUT;
  }

  void Signal() {
    LONG dummy;
    ReleaseSemaphore(sem, 1, &dummy);
  }

 private:
  HANDLE sem;
};


Semaphore* OS::CreateSemaphore(int count) {
  return new Win32Semaphore(count);
}


// ----------------------------------------------------------------------------
// Win32 socket support.
//

class Win32Socket : public Socket {
 public:
  explicit Win32Socket() {
    // Create the socket.
    socket_ = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  }
  explicit Win32Socket(SOCKET socket): socket_(socket) { }
  virtual ~Win32Socket() { Shutdown(); }

  // Server initialization.
  bool Bind(const int port);
  bool Listen(int backlog) const;
  Socket* Accept() const;

  // Client initialization.
  bool Connect(const char* host, const char* port);

  // Shutdown socket for both read and write.
  bool Shutdown();

  // Data Transimission
  int Send(const char* data, int len) const;
  int Receive(char* data, int len) const;

  bool SetReuseAddress(bool reuse_address);

  bool IsValid() const { return socket_ != INVALID_SOCKET; }

 private:
  SOCKET socket_;
};


bool Win32Socket::Bind(const int port) {
  if (!IsValid())  {
    return false;
  }

  sockaddr_in addr;
  memset(&addr, 0, sizeof(addr));
  addr.sin_family = AF_INET;
  addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  addr.sin_port = htons(port);
  int status = bind(socket_,
                    reinterpret_cast<struct sockaddr *>(&addr),
                    sizeof(addr));
  return status == 0;
}


bool Win32Socket::Listen(int backlog) const {
  if (!IsValid()) {
    return false;
  }

  int status = listen(socket_, backlog);
  return status == 0;
}


Socket* Win32Socket::Accept() const {
  if (!IsValid()) {
    return NULL;
  }

  SOCKET socket = accept(socket_, NULL, NULL);
  if (socket == INVALID_SOCKET) {
    return NULL;
  } else {
    return new Win32Socket(socket);
  }
}


bool Win32Socket::Connect(const char* host, const char* port) {
  if (!IsValid()) {
    return false;
  }

  // Lookup host and port.
  struct addrinfo *result = NULL;
  struct addrinfo hints;
  memset(&hints, 0, sizeof(addrinfo));
  hints.ai_family = AF_INET;
  hints.ai_socktype = SOCK_STREAM;
  hints.ai_protocol = IPPROTO_TCP;
  int status = getaddrinfo(host, port, &hints, &result);
  if (status != 0) {
    return false;
  }

  // Connect.
  status = connect(socket_,
                   result->ai_addr,
                   static_cast<int>(result->ai_addrlen));
  freeaddrinfo(result);
  return status == 0;
}


bool Win32Socket::Shutdown() {
  if (IsValid()) {
    // Shutdown socket for both read and write.
    int status = shutdown(socket_, SD_BOTH);
    closesocket(socket_);
    socket_ = INVALID_SOCKET;
    return status == SOCKET_ERROR;
  }
  return true;
}


int Win32Socket::Send(const char* data, int len) const {
  if (len <= 0) return 0;
  int written = 0;
  while (written < len) {
    int status = send(socket_, data + written, len - written, 0);
    if (status == 0) {
      break;
    } else if (status > 0) {
      written += status;
    } else {
      return 0;
    }
  }
  return written;
}


int Win32Socket::Receive(char* data, int len) const {
  if (len <= 0) return 0;
  int status = recv(socket_, data, len, 0);
  return (status == SOCKET_ERROR) ? 0 : status;
}


bool Win32Socket::SetReuseAddress(bool reuse_address) {
  BOOL on = reuse_address ? true : false;
  int status = setsockopt(socket_, SOL_SOCKET, SO_REUSEADDR,
                          reinterpret_cast<char*>(&on), sizeof(on));
  return status == SOCKET_ERROR;
}


bool Socket::SetUp() {
  // Initialize Winsock32
  int err;
  WSADATA winsock_data;
  WORD version_requested = MAKEWORD(1, 0);
  err = WSAStartup(version_requested, &winsock_data);
  if (err != 0) {
    PrintF("Unable to initialize Winsock, err = %d\n", Socket::LastError());
  }

  return err == 0;
}


int Socket::LastError() {
  return WSAGetLastError();
}


uint16_t Socket::HToN(uint16_t value) {
  return htons(value);
}


uint16_t Socket::NToH(uint16_t value) {
  return ntohs(value);
}


uint32_t Socket::HToN(uint32_t value) {
  return htonl(value);
}


uint32_t Socket::NToH(uint32_t value) {
  return ntohl(value);
}


Socket* OS::CreateSocket() {
  return new Win32Socket();
}


// ----------------------------------------------------------------------------
// Win32 profiler support.

class Sampler::PlatformData : public Malloced {
 public:
  // Get a handle to the calling thread. This is the thread that we are
  // going to profile. We need to make a copy of the handle because we are
  // going to use it in the sampler thread. Using GetThreadHandle() will
  // not work in this case. We're using OpenThread because DuplicateHandle
  // for some reason doesn't work in Chrome's sandbox.
  PlatformData() : profiled_thread_(OpenThread(THREAD_GET_CONTEXT |
                                               THREAD_SUSPEND_RESUME |
                                               THREAD_QUERY_INFORMATION,
                                               false,
                                               GetCurrentThreadId())) {}

  ~PlatformData() {
    if (profiled_thread_ != NULL) {
      CloseHandle(profiled_thread_);
      profiled_thread_ = NULL;
    }
  }

  HANDLE profiled_thread() { return profiled_thread_; }

 private:
  HANDLE profiled_thread_;
};


class SamplerThread : public Thread {
 public:
  static const int kSamplerThreadStackSize = 64 * KB;

  explicit SamplerThread(int interval)
      : Thread(Thread::Options("SamplerThread", kSamplerThreadStackSize)),
        interval_(interval) {}

  static void SetUp() { if (!mutex_) mutex_ = OS::CreateMutex(); }
  static void TearDown() { delete mutex_; }

  static void AddActiveSampler(Sampler* sampler) {
    ScopedLock lock(mutex_);
    SamplerRegistry::AddActiveSampler(sampler);
    if (instance_ == NULL) {
      instance_ = new SamplerThread(sampler->interval());
      instance_->Start();
    } else {
      ASSERT(instance_->interval_ == sampler->interval());
    }
  }

  static void RemoveActiveSampler(Sampler* sampler) {
    ScopedLock lock(mutex_);
    SamplerRegistry::RemoveActiveSampler(sampler);
    if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
      RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
      delete instance_;
      instance_ = NULL;
    }
  }

  // Implement Thread::Run().
  virtual void Run() {
    SamplerRegistry::State state;
    while ((state = SamplerRegistry::GetState()) !=
           SamplerRegistry::HAS_NO_SAMPLERS) {
      bool cpu_profiling_enabled =
          (state == SamplerRegistry::HAS_CPU_PROFILING_SAMPLERS);
      bool runtime_profiler_enabled = RuntimeProfiler::IsEnabled();
      // When CPU profiling is enabled both JavaScript and C++ code is
      // profiled. We must not suspend.
      if (!cpu_profiling_enabled) {
        if (rate_limiter_.SuspendIfNecessary()) continue;
      }
      if (cpu_profiling_enabled) {
        if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this)) {
          return;
        }
      }
      if (runtime_profiler_enabled) {
        if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile, NULL)) {
          return;
        }
      }
      OS::Sleep(interval_);
    }
  }

  static void DoCpuProfile(Sampler* sampler, void* raw_sampler_thread) {
    if (!sampler->isolate()->IsInitialized()) return;
    if (!sampler->IsProfiling()) return;
    SamplerThread* sampler_thread =
        reinterpret_cast<SamplerThread*>(raw_sampler_thread);
    sampler_thread->SampleContext(sampler);
  }

  static void DoRuntimeProfile(Sampler* sampler, void* ignored) {
    if (!sampler->isolate()->IsInitialized()) return;
    sampler->isolate()->runtime_profiler()->NotifyTick();
  }

  void SampleContext(Sampler* sampler) {
    HANDLE profiled_thread = sampler->platform_data()->profiled_thread();
    if (profiled_thread == NULL) return;

    // Context used for sampling the register state of the profiled thread.
    CONTEXT context;
    memset(&context, 0, sizeof(context));

    TickSample sample_obj;
    TickSample* sample = CpuProfiler::TickSampleEvent(sampler->isolate());
    if (sample == NULL) sample = &sample_obj;

    static const DWORD kSuspendFailed = static_cast<DWORD>(-1);
    if (SuspendThread(profiled_thread) == kSuspendFailed) return;
    sample->state = sampler->isolate()->current_vm_state();

    context.ContextFlags = CONTEXT_FULL;
    if (GetThreadContext(profiled_thread, &context) != 0) {
#if V8_HOST_ARCH_X64
      sample->pc = reinterpret_cast<Address>(context.Rip);
      sample->sp = reinterpret_cast<Address>(context.Rsp);
      sample->fp = reinterpret_cast<Address>(context.Rbp);
#else
      sample->pc = reinterpret_cast<Address>(context.Eip);
      sample->sp = reinterpret_cast<Address>(context.Esp);
      sample->fp = reinterpret_cast<Address>(context.Ebp);
#endif
      sampler->SampleStack(sample);
      sampler->Tick(sample);
    }
    ResumeThread(profiled_thread);
  }

  const int interval_;
  RuntimeProfilerRateLimiter rate_limiter_;

  // Protects the process wide state below.
  static Mutex* mutex_;
  static SamplerThread* instance_;

 private:
  DISALLOW_COPY_AND_ASSIGN(SamplerThread);
};


Mutex* SamplerThread::mutex_ = NULL;
SamplerThread* SamplerThread::instance_ = NULL;


void OS::SetUp() {
  // Seed the random number generator.
  // Convert the current time to a 64-bit integer first, before converting it
  // to an unsigned. Going directly can cause an overflow and the seed to be
  // set to all ones. The seed will be identical for different instances that
  // call this setup code within the same millisecond.
  uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
  srand(static_cast<unsigned int>(seed));
  limit_mutex = CreateMutex();
  SamplerThread::SetUp();
}


void OS::TearDown() {
  SamplerThread::TearDown();
  delete limit_mutex;
}


Sampler::Sampler(Isolate* isolate, int interval)
    : isolate_(isolate),
      interval_(interval),
      profiling_(false),
      active_(false),
      samples_taken_(0) {
  data_ = new PlatformData;
}


Sampler::~Sampler() {
  ASSERT(!IsActive());
  delete data_;
}


void Sampler::Start() {
  ASSERT(!IsActive());
  SetActive(true);
  SamplerThread::AddActiveSampler(this);
}


void Sampler::Stop() {
  ASSERT(IsActive());
  SamplerThread::RemoveActiveSampler(this);
  SetActive(false);
}


} }  // namespace v8::internal
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