Move timing files into base/time, install forwarding headers.

base/time_win.cc

Index: base/time_win.cc
diff --git a/base/time_win.cc b/base/time_win.cc
deleted file mode 100644
index 0f5c4010ea104f6ccef5cb687124614636b0501f..0000000000000000000000000000000000000000
--- a/base/time_win.cc
+++ /dev/null
@@ -1,486 +0,0 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-
-// Windows Timer Primer
-//
-// A good article:  http://www.ddj.com/windows/184416651
-// A good mozilla bug:  http://bugzilla.mozilla.org/show_bug.cgi?id=363258
-//
-// The default windows timer, GetSystemTimeAsFileTime is not very precise.
-// It is only good to ~15.5ms.
-//
-// QueryPerformanceCounter is the logical choice for a high-precision timer.
-// However, it is known to be buggy on some hardware.  Specifically, it can
-// sometimes "jump".  On laptops, QPC can also be very expensive to call.
-// It's 3-4x slower than timeGetTime() on desktops, but can be 10x slower
-// on laptops.  A unittest exists which will show the relative cost of various
-// timers on any system.
-//
-// The next logical choice is timeGetTime().  timeGetTime has a precision of
-// 1ms, but only if you call APIs (timeBeginPeriod()) which affect all other
-// applications on the system.  By default, precision is only 15.5ms.
-// Unfortunately, we don't want to call timeBeginPeriod because we don't
-// want to affect other applications.  Further, on mobile platforms, use of
-// faster multimedia timers can hurt battery life.  See the intel
-// article about this here:
-// http://softwarecommunity.intel.com/articles/eng/1086.htm
-//
-// To work around all this, we're going to generally use timeGetTime().  We
-// will only increase the system-wide timer if we're not running on battery
-// power.  Using timeBeginPeriod(1) is a requirement in order to make our
-// message loop waits have the same resolution that our time measurements
-// do.  Otherwise, WaitForSingleObject(..., 1) will no less than 15ms when
-// there is nothing else to waken the Wait.
-
-#include "base/time.h"
-
-#pragma comment(lib, "winmm.lib")
-#include <windows.h>
-#include <mmsystem.h>
-
-#include "base/basictypes.h"
-#include "base/logging.h"
-#include "base/cpu.h"
-#include "base/memory/singleton.h"
-#include "base/synchronization/lock.h"
-
-using base::Time;
-using base::TimeDelta;
-using base::TimeTicks;
-
-namespace {
-
-// From MSDN, FILETIME "Contains a 64-bit value representing the number of
-// 100-nanosecond intervals since January 1, 1601 (UTC)."
-int64 FileTimeToMicroseconds(const FILETIME& ft) {
-  // Need to bit_cast to fix alignment, then divide by 10 to convert
-  // 100-nanoseconds to milliseconds. This only works on little-endian
-  // machines.
-  return bit_cast<int64, FILETIME>(ft) / 10;
-}
-
-void MicrosecondsToFileTime(int64 us, FILETIME* ft) {
-  DCHECK_GE(us, 0LL) << "Time is less than 0, negative values are not "
-      "representable in FILETIME";
-
-  // Multiply by 10 to convert milliseconds to 100-nanoseconds. Bit_cast will
-  // handle alignment problems. This only works on little-endian machines.
-  *ft = bit_cast<FILETIME, int64>(us * 10);
-}
-
-int64 CurrentWallclockMicroseconds() {
-  FILETIME ft;
-  ::GetSystemTimeAsFileTime(&ft);
-  return FileTimeToMicroseconds(ft);
-}
-
-// Time between resampling the un-granular clock for this API.  60 seconds.
-const int kMaxMillisecondsToAvoidDrift = 60 * Time::kMillisecondsPerSecond;
-
-int64 initial_time = 0;
-TimeTicks initial_ticks;
-
-void InitializeClock() {
-  initial_ticks = TimeTicks::Now();
-  initial_time = CurrentWallclockMicroseconds();
-}
-
-}  // namespace
-
-// Time -----------------------------------------------------------------------
-
-// The internal representation of Time uses FILETIME, whose epoch is 1601-01-01
-// 00:00:00 UTC.  ((1970-1601)*365+89)*24*60*60*1000*1000, where 89 is the
-// number of leap year days between 1601 and 1970: (1970-1601)/4 excluding
-// 1700, 1800, and 1900.
-// static
-const int64 Time::kTimeTToMicrosecondsOffset = GG_INT64_C(11644473600000000);
-
-bool Time::high_resolution_timer_enabled_ = false;
-int Time::high_resolution_timer_activated_ = 0;
-
-// static
-Time Time::Now() {
-  if (initial_time == 0)
-    InitializeClock();
-
-  // We implement time using the high-resolution timers so that we can get
-  // timeouts which are smaller than 10-15ms.  If we just used
-  // CurrentWallclockMicroseconds(), we'd have the less-granular timer.
-  //
-  // To make this work, we initialize the clock (initial_time) and the
-  // counter (initial_ctr).  To compute the initial time, we can check
-  // the number of ticks that have elapsed, and compute the delta.
-  //
-  // To avoid any drift, we periodically resync the counters to the system
-  // clock.
-  while (true) {
-    TimeTicks ticks = TimeTicks::Now();
-
-    // Calculate the time elapsed since we started our timer
-    TimeDelta elapsed = ticks - initial_ticks;
-
-    // Check if enough time has elapsed that we need to resync the clock.
-    if (elapsed.InMilliseconds() > kMaxMillisecondsToAvoidDrift) {
-      InitializeClock();
-      continue;
-    }
-
-    return Time(elapsed + Time(initial_time));
-  }
-}
-
-// static
-Time Time::NowFromSystemTime() {
-  // Force resync.
-  InitializeClock();
-  return Time(initial_time);
-}
-
-// static
-Time Time::FromFileTime(FILETIME ft) {
-  if (bit_cast<int64, FILETIME>(ft) == 0)
-    return Time();
-  if (ft.dwHighDateTime == std::numeric_limits<DWORD>::max() &&
-      ft.dwLowDateTime == std::numeric_limits<DWORD>::max())
-    return Max();
-  return Time(FileTimeToMicroseconds(ft));
-}
-
-FILETIME Time::ToFileTime() const {
-  if (is_null())
-    return bit_cast<FILETIME, int64>(0);
-  if (is_max()) {
-    FILETIME result;
-    result.dwHighDateTime = std::numeric_limits<DWORD>::max();
-    result.dwLowDateTime = std::numeric_limits<DWORD>::max();
-    return result;
-  }
-  FILETIME utc_ft;
-  MicrosecondsToFileTime(us_, &utc_ft);
-  return utc_ft;
-}
-
-// static
-void Time::EnableHighResolutionTimer(bool enable) {
-  // Test for single-threaded access.
-  static PlatformThreadId my_thread = PlatformThread::CurrentId();
-  DCHECK(PlatformThread::CurrentId() == my_thread);
-
-  if (high_resolution_timer_enabled_ == enable)
-    return;
-
-  high_resolution_timer_enabled_ = enable;
-}
-
-// static
-bool Time::ActivateHighResolutionTimer(bool activating) {
-  if (!high_resolution_timer_enabled_ && activating)
-    return false;
-
-  // Using anything other than 1ms makes timers granular
-  // to that interval.
-  const int kMinTimerIntervalMs = 1;
-  MMRESULT result;
-  if (activating) {
-    result = timeBeginPeriod(kMinTimerIntervalMs);
-    high_resolution_timer_activated_++;
-  } else {
-    result = timeEndPeriod(kMinTimerIntervalMs);
-    high_resolution_timer_activated_--;
-  }
-  return result == TIMERR_NOERROR;
-}
-
-// static
-bool Time::IsHighResolutionTimerInUse() {
-  // Note:  we should track the high_resolution_timer_activated_ value
-  // under a lock if we want it to be accurate in a system with multiple
-  // message loops.  We don't do that - because we don't want to take the
-  // expense of a lock for this.  We *only* track this value so that unit
-  // tests can see if the high resolution timer is on or off.
-  return high_resolution_timer_enabled_ &&
-      high_resolution_timer_activated_ > 0;
-}
-
-// static
-Time Time::FromExploded(bool is_local, const Exploded& exploded) {
-  // Create the system struct representing our exploded time. It will either be
-  // in local time or UTC.
-  SYSTEMTIME st;
-  st.wYear = exploded.year;
-  st.wMonth = exploded.month;
-  st.wDayOfWeek = exploded.day_of_week;
-  st.wDay = exploded.day_of_month;
-  st.wHour = exploded.hour;
-  st.wMinute = exploded.minute;
-  st.wSecond = exploded.second;
-  st.wMilliseconds = exploded.millisecond;
-
-  FILETIME ft;
-  bool success = true;
-  // Ensure that it's in UTC.
-  if (is_local) {
-    SYSTEMTIME utc_st;
-    success = TzSpecificLocalTimeToSystemTime(NULL, &st, &utc_st) &&
-              SystemTimeToFileTime(&utc_st, &ft);
-  } else {
-    success = !!SystemTimeToFileTime(&st, &ft);
-  }
-
-  if (!success) {
-    NOTREACHED() << "Unable to convert time";
-    return Time(0);
-  }
-  return Time(FileTimeToMicroseconds(ft));
-}
-
-void Time::Explode(bool is_local, Exploded* exploded) const {
-  if (us_ < 0LL) {
-    // We are not able to convert it to FILETIME.
-    ZeroMemory(exploded, sizeof(*exploded));
-    return;
-  }
-
-  // FILETIME in UTC.
-  FILETIME utc_ft;
-  MicrosecondsToFileTime(us_, &utc_ft);
-
-  // FILETIME in local time if necessary.
-  bool success = true;
-  // FILETIME in SYSTEMTIME (exploded).
-  SYSTEMTIME st;
-  if (is_local) {
-    SYSTEMTIME utc_st;
-    // We don't use FileTimeToLocalFileTime here, since it uses the current
-    // settings for the time zone and daylight saving time. Therefore, if it is
-    // daylight saving time, it will take daylight saving time into account,
-    // even if the time you are converting is in standard time.
-    success = FileTimeToSystemTime(&utc_ft, &utc_st) &&
-              SystemTimeToTzSpecificLocalTime(NULL, &utc_st, &st);
-  } else {
-    success = !!FileTimeToSystemTime(&utc_ft, &st);
-  }
-
-  if (!success) {
-    NOTREACHED() << "Unable to convert time, don't know why";
-    ZeroMemory(exploded, sizeof(*exploded));
-    return;
-  }
-
-  exploded->year = st.wYear;
-  exploded->month = st.wMonth;
-  exploded->day_of_week = st.wDayOfWeek;
-  exploded->day_of_month = st.wDay;
-  exploded->hour = st.wHour;
-  exploded->minute = st.wMinute;
-  exploded->second = st.wSecond;
-  exploded->millisecond = st.wMilliseconds;
-}
-
-// TimeTicks ------------------------------------------------------------------
-namespace {
-
-// We define a wrapper to adapt between the __stdcall and __cdecl call of the
-// mock function, and to avoid a static constructor.  Assigning an import to a
-// function pointer directly would require setup code to fetch from the IAT.
-DWORD timeGetTimeWrapper() {
-  return timeGetTime();
-}
-
-DWORD (*tick_function)(void) = &timeGetTimeWrapper;
-
-// Accumulation of time lost due to rollover (in milliseconds).
-int64 rollover_ms = 0;
-
-// The last timeGetTime value we saw, to detect rollover.
-DWORD last_seen_now = 0;
-
-// Lock protecting rollover_ms and last_seen_now.
-// Note: this is a global object, and we usually avoid these. However, the time
-// code is low-level, and we don't want to use Singletons here (it would be too
-// easy to use a Singleton without even knowing it, and that may lead to many
-// gotchas). Its impact on startup time should be negligible due to low-level
-// nature of time code.
-base::Lock rollover_lock;
-
-// We use timeGetTime() to implement TimeTicks::Now().  This can be problematic
-// because it returns the number of milliseconds since Windows has started,
-// which will roll over the 32-bit value every ~49 days.  We try to track
-// rollover ourselves, which works if TimeTicks::Now() is called at least every
-// 49 days.
-TimeDelta RolloverProtectedNow() {
-  base::AutoLock locked(rollover_lock);
-  // We should hold the lock while calling tick_function to make sure that
-  // we keep last_seen_now stay correctly in sync.
-  DWORD now = tick_function();
-  if (now < last_seen_now)
-    rollover_ms += 0x100000000I64;  // ~49.7 days.
-  last_seen_now = now;
-  return TimeDelta::FromMilliseconds(now + rollover_ms);
-}
-
-// Overview of time counters:
-// (1) CPU cycle counter. (Retrieved via RDTSC)
-// The CPU counter provides the highest resolution time stamp and is the least
-// expensive to retrieve. However, the CPU counter is unreliable and should not
-// be used in production. Its biggest issue is that it is per processor and it
-// is not synchronized between processors. Also, on some computers, the counters
-// will change frequency due to thermal and power changes, and stop in some
-// states.
-//
-// (2) QueryPerformanceCounter (QPC). The QPC counter provides a high-
-// resolution (100 nanoseconds) time stamp but is comparatively more expensive
-// to retrieve. What QueryPerformanceCounter actually does is up to the HAL.
-// (with some help from ACPI).
-// According to http://blogs.msdn.com/oldnewthing/archive/2005/09/02/459952.aspx
-// in the worst case, it gets the counter from the rollover interrupt on the
-// programmable interrupt timer. In best cases, the HAL may conclude that the
-// RDTSC counter runs at a constant frequency, then it uses that instead. On
-// multiprocessor machines, it will try to verify the values returned from
-// RDTSC on each processor are consistent with each other, and apply a handful
-// of workarounds for known buggy hardware. In other words, QPC is supposed to
-// give consistent result on a multiprocessor computer, but it is unreliable in
-// reality due to bugs in BIOS or HAL on some, especially old computers.
-// With recent updates on HAL and newer BIOS, QPC is getting more reliable but
-// it should be used with caution.
-//
-// (3) System time. The system time provides a low-resolution (typically 10ms
-// to 55 milliseconds) time stamp but is comparatively less expensive to
-// retrieve and more reliable.
-class HighResNowSingleton {
- public:
-  static HighResNowSingleton* GetInstance() {
-    return Singleton<HighResNowSingleton>::get();
-  }
-
-  bool IsUsingHighResClock() {
-    return ticks_per_second_ != 0.0;
-  }
-
-  void DisableHighResClock() {
-    ticks_per_second_ = 0.0;
-  }
-
-  TimeDelta Now() {
-    if (IsUsingHighResClock())
-      return TimeDelta::FromMicroseconds(UnreliableNow());
-
-    // Just fallback to the slower clock.
-    return RolloverProtectedNow();
-  }
-
-  int64 GetQPCDriftMicroseconds() {
-    if (!IsUsingHighResClock())
-      return 0;
-    return abs((UnreliableNow() - ReliableNow()) - skew_);
-  }
-
-  int64 QPCValueToMicroseconds(LONGLONG qpc_value) {
-    if (!ticks_per_second_)
-      return 0;
-
-    // Intentionally calculate microseconds in a round about manner to avoid
-    // overflow and precision issues. Think twice before simplifying!
-    int64 whole_seconds = qpc_value / ticks_per_second_;
-    int64 leftover_ticks = qpc_value % ticks_per_second_;
-    int64 microseconds = (whole_seconds * Time::kMicrosecondsPerSecond) +
-                         ((leftover_ticks * Time::kMicrosecondsPerSecond) /
-                          ticks_per_second_);
-    return microseconds;
-  }
-
- private:
-  HighResNowSingleton()
-    : ticks_per_second_(0),
-      skew_(0) {
-    InitializeClock();
-
-    // On Athlon X2 CPUs (e.g. model 15) QueryPerformanceCounter is
-    // unreliable.  Fallback to low-res clock.
-    base::CPU cpu;
-    if (cpu.vendor_name() == "AuthenticAMD" && cpu.family() == 15)
-      DisableHighResClock();
-  }
-
-  // Synchronize the QPC clock with GetSystemTimeAsFileTime.
-  void InitializeClock() {
-    LARGE_INTEGER ticks_per_sec = {0};
-    if (!QueryPerformanceFrequency(&ticks_per_sec))
-      return;  // Broken, we don't guarantee this function works.
-    ticks_per_second_ = ticks_per_sec.QuadPart;
-
-    skew_ = UnreliableNow() - ReliableNow();
-  }
-
-  // Get the number of microseconds since boot in an unreliable fashion.
-  int64 UnreliableNow() {
-    LARGE_INTEGER now;
-    QueryPerformanceCounter(&now);
-    return QPCValueToMicroseconds(now.QuadPart);
-  }
-
-  // Get the number of microseconds since boot in a reliable fashion.
-  int64 ReliableNow() {
-    return RolloverProtectedNow().InMicroseconds();
-  }
-
-  int64 ticks_per_second_;  // 0 indicates QPF failed and we're broken.
-  int64 skew_;  // Skew between lo-res and hi-res clocks (for debugging).
-
-  friend struct DefaultSingletonTraits<HighResNowSingleton>;
-};
-
-}  // namespace
-
-// static
-TimeTicks::TickFunctionType TimeTicks::SetMockTickFunction(
-    TickFunctionType ticker) {
-  base::AutoLock locked(rollover_lock);
-  TickFunctionType old = tick_function;
-  tick_function = ticker;
-  rollover_ms = 0;
-  last_seen_now = 0;
-  return old;
-}
-
-// static
-TimeTicks TimeTicks::Now() {
-  return TimeTicks() + RolloverProtectedNow();
-}
-
-// static
-TimeTicks TimeTicks::HighResNow() {
-  return TimeTicks() + HighResNowSingleton::GetInstance()->Now();
-}
-
-// static
-TimeTicks TimeTicks::NowFromSystemTraceTime() {
-  return HighResNow();
-}
-
-// static
-int64 TimeTicks::GetQPCDriftMicroseconds() {
-  return HighResNowSingleton::GetInstance()->GetQPCDriftMicroseconds();
-}
-
-// static
-TimeTicks TimeTicks::FromQPCValue(LONGLONG qpc_value) {
-  return TimeTicks(
-      HighResNowSingleton::GetInstance()->QPCValueToMicroseconds(qpc_value));
-}
-
-// static
-bool TimeTicks::IsHighResClockWorking() {
-  return HighResNowSingleton::GetInstance()->IsUsingHighResClock();
-}
-
-// TimeDelta ------------------------------------------------------------------
-
-// static
-TimeDelta TimeDelta::FromQPCValue(LONGLONG qpc_value) {
-  return TimeDelta(
-      HighResNowSingleton::GetInstance()->QPCValueToMicroseconds(qpc_value));
-}