platform-win32.cc.svn-base

Google浏览器V8内核代码

// Copyright 2006-2008 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.
#ifndef WIN32_LEAN_AND_MEAN
// WIN32_LEAN_AND_MEAN implies NOCRYPT and NOGDI.
#define WIN32_LEAN_AND_MEAN
#endif
#ifndef NOMINMAX
#define NOMINMAX
#endif
#ifndef NOKERNEL
#define NOKERNEL
#endif
#ifndef NOUSER
#define NOUSER
#endif
#ifndef NOSERVICE
#define NOSERVICE
#endif
#ifndef NOSOUND
#define NOSOUND
#endif
#ifndef NOMCX
#define NOMCX
#endif

#include <windows.h>

#include <mmsystem.h>  // For timeGetTime().
#include <dbghelp.h>  // For SymLoadModule64 and al.
#include <tlhelp32.h>  // For Module32First and al.

// These aditional WIN32 includes have to be right here as the #undef's below
// makes it impossible to have them elsewhere.
#include <winsock2.h>
#include <process.h>  // for _beginthreadex()
#include <stdlib.h>

#pragma comment(lib, "winmm.lib")  // force linkage with winmm.

#undef VOID
#undef DELETE
#undef IN
#undef THIS
#undef CONST
#undef NAN
#undef GetObject
#undef CreateMutex
#undef CreateSemaphore

#include "v8.h"

#include "platform.h"

// Extra POSIX/ANSI routines for Win32. Please refer to The Open Group Base
// Specification for specification of the correct semantics for these
// functions.
// (http://www.opengroup.org/onlinepubs/000095399/)

// Test for finite value - usually defined in math.h
namespace v8 {
namespace internal {

int isfinite(double x) {
  return _finite(x);
}

}  // namespace v8
}  // namespace internal

// Test for a NaN (not a number) value - usually defined in math.h
int isnan(double x) {
  return _isnan(x);
}


// Test for infinity - usually defined in math.h
int isinf(double x) {
  return (_fpclass(x) & (_FPCLASS_PINF | _FPCLASS_NINF)) != 0;
}


// Test if x is less than y and both nominal - usually defined in math.h
int isless(double x, double y) {
  return isnan(x) || isnan(y) ? 0 : x < y;
}


// Test if x is greater than y and both nominal - usually defined in math.h
int isgreater(double x, double y) {
  return isnan(x) || isnan(y) ? 0 : x > y;
}


// Classify floating point number - usually defined in math.h
int fpclassify(double x) {
  // Use the MS-specific _fpclass() for classification.
  int flags = _fpclass(x);

  // Determine class. We cannot use a switch statement because
  // the _FPCLASS_ constants are defined as flags.
  if (flags & (_FPCLASS_PN | _FPCLASS_NN)) return FP_NORMAL;
  if (flags & (_FPCLASS_PZ | _FPCLASS_NZ)) return FP_ZERO;
  if (flags & (_FPCLASS_PD | _FPCLASS_ND)) return FP_SUBNORMAL;
  if (flags & (_FPCLASS_PINF | _FPCLASS_NINF)) return FP_INFINITE;

  // All cases should be covered by the code above.
  ASSERT(flags & (_FPCLASS_SNAN | _FPCLASS_QNAN));
  return FP_NAN;
}


// Test sign - usually defined in math.h
int signbit(double x) {
  // We need to take care of the special case of both positive
  // and negative versions of zero.
  if (x == 0)
    return _fpclass(x) & _FPCLASS_NZ;
  else
    return x < 0;
}


// Generate a pseudo-random number in the range 0-2^31-1. Usually
// defined in stdlib.h
int random() {
  return rand();
}


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


// 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);
}

namespace v8 { namespace internal {

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

// ----------------------------------------------------------------------------
// The Time class represents time on win32. A timestamp is represented as
// a 64-bit integer in 100 nano-seconds 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 = 116444736000000000;
  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<uint64_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;

  // 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.
  OS::SNPrintF(Vector<char>(std_tz_name_, kTzNameSize),
               "%S",
               tzinfo_.StandardName);
  std_tz_name_[kTzNameSize - 1] = '\0';
  OS::SNPrintF(Vector<char>(dst_tz_name_, kTzNameSize),
               "%S",
               tzinfo_.DaylightName);
  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.