gecko-dev/mozglue/misc/TimeStamp_windows.h

94 строки
3.1 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_TimeStamp_windows_h
#define mozilla_TimeStamp_windows_h
#include "mozilla/Types.h"
namespace mozilla {
/**
* The [mt] unit:
*
* Many values are kept in ticks of the Performance Counter x 1000,
* further just referred as [mt], meaning milli-ticks.
*
* This is needed to preserve maximum precision of the performance frequency
* representation. GetTickCount64 values in milliseconds are multiplied with
* frequency per second. Therefore we need to multiply QPC value by 1000 to
* have the same units to allow simple arithmentic with both QPC and GTC.
*/
#define ms2mt(x) ((x)*mozilla::GetQueryPerformanceFrequencyPerSec())
#define mt2ms(x) ((x) / mozilla::GetQueryPerformanceFrequencyPerSec())
#define mt2ms_f(x) (double(x) / mozilla::GetQueryPerformanceFrequencyPerSec())
MFBT_API uint64_t GetQueryPerformanceFrequencyPerSec();
class TimeStamp;
class TimeStampValue;
TimeStampValue NowInternal(bool aHighResolution);
class TimeStampValue {
friend TimeStampValue NowInternal(bool);
friend bool IsCanonicalTimeStamp(TimeStampValue);
friend struct IPC::ParamTraits<mozilla::TimeStampValue>;
friend class TimeStamp;
// Both QPC and GTC are kept in [mt] units.
uint64_t mGTC;
uint64_t mQPC;
bool mIsNull;
bool mHasQPC;
MFBT_API TimeStampValue(uint64_t aGTC, uint64_t aQPC, bool aHasQPC);
MFBT_API uint64_t CheckQPC(const TimeStampValue& aOther) const;
// This struct is used to allow doing TimeStampValue a = 0 and similar
struct _SomethingVeryRandomHere;
constexpr MOZ_IMPLICIT TimeStampValue(_SomethingVeryRandomHere* aNullValue)
: mGTC(0), mQPC(0), mIsNull(true), mHasQPC(false) {}
public:
MFBT_API uint64_t operator-(const TimeStampValue& aOther) const;
TimeStampValue operator+(const int64_t aOther) const {
return TimeStampValue(mGTC + aOther, mQPC + aOther, mHasQPC);
}
TimeStampValue operator-(const int64_t aOther) const {
return TimeStampValue(mGTC - aOther, mQPC - aOther, mHasQPC);
}
MFBT_API TimeStampValue& operator+=(const int64_t aOther);
MFBT_API TimeStampValue& operator-=(const int64_t aOther);
bool operator<(const TimeStampValue& aOther) const {
return int64_t(*this - aOther) < 0;
}
bool operator>(const TimeStampValue& aOther) const {
return int64_t(*this - aOther) > 0;
}
bool operator<=(const TimeStampValue& aOther) const {
return int64_t(*this - aOther) <= 0;
}
bool operator>=(const TimeStampValue& aOther) const {
return int64_t(*this - aOther) >= 0;
}
bool operator==(const TimeStampValue& aOther) const {
return int64_t(*this - aOther) == 0;
}
bool operator!=(const TimeStampValue& aOther) const {
return int64_t(*this - aOther) != 0;
}
bool IsNull() const { return mIsNull; }
};
} // namespace mozilla
#endif /* mozilla_TimeStamp_h */