webrtc/system_wrappers/interface/tick_util.h

305 lines
8.0 KiB
C++

/*
* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
// System independant wrapper for polling elapsed time in ms and us.
// The implementation works in the tick domain which can be mapped over to the
// time domain.
#ifndef WEBRTC_SYSTEM_WRAPPERS_INTERFACE_TICK_UTIL_H_
#define WEBRTC_SYSTEM_WRAPPERS_INTERFACE_TICK_UTIL_H_
#if _WIN32
#include <windows.h>
#include <mmsystem.h>
#elif WEBRTC_LINUX
#include <ctime>
#else
#include <sys/time.h>
#include <time.h>
#endif
#include "typedefs.h"
namespace webrtc {
class TickInterval;
class TickTime
{
public:
// Current time in the tick domain.
static TickTime Now();
// Now in the time domain in ms.
static WebRtc_Word64 MillisecondTimestamp();
// Now in the time domain in us.
static WebRtc_Word64 MicrosecondTimestamp();
WebRtc_Word64 Ticks() const;
static WebRtc_Word64 MillisecondsToTicks(const WebRtc_Word64 ms);
static WebRtc_Word64 TicksToMilliseconds(const WebRtc_Word64 ticks);
// Returns a TickTime that is ticks later than the passed TickTime
friend TickTime operator+(const TickTime lhs, const WebRtc_Word64 ticks);
TickTime& operator+=(const WebRtc_Word64& rhs);
// Returns a TickInterval that is the difference in ticks beween rhs and lhs
friend TickInterval operator-(const TickTime& lhs, const TickTime& rhs);
private:
WebRtc_Word64 _ticks;
};
class TickInterval
{
public:
TickInterval();
WebRtc_Word64 Milliseconds() const;
WebRtc_Word64 Microseconds() const;
// Returns the sum of two TickIntervals as a TickInterval
friend TickInterval operator+(const TickInterval& lhs,
const TickInterval& rhs);
TickInterval& operator-=(const TickInterval& rhs);
// Returns a TickInterval corresponding to rhs - lhs
friend TickInterval operator-(const TickInterval& lhs,
const TickInterval& rhs);
TickInterval& operator+=(const TickInterval& rhs);
private:
TickInterval(WebRtc_Word64 interval);
friend class TickTime;
friend TickInterval operator-(const TickTime& lhs, const TickTime& rhs);
private:
WebRtc_Word64 _interval;
};
inline TickInterval operator+(const TickInterval& lhs, const TickInterval& rhs)
{
return TickInterval(lhs._interval + rhs._interval);
}
inline TickInterval operator-(const TickInterval& lhs, const TickInterval& rhs)
{
return TickInterval(lhs._interval - rhs._interval);
}
inline TickInterval operator-(const TickTime& lhs,const TickTime& rhs)
{
return TickInterval(lhs._ticks - rhs._ticks);
}
inline TickTime operator+(const TickTime lhs, const WebRtc_Word64 ticks)
{
TickTime time = lhs;
time._ticks += ticks;
return time;
}
inline TickTime TickTime::Now()
{
TickTime result;
#if _WIN32
#ifdef USE_QUERY_PERFORMANCE_COUNTER
// QueryPerformanceCounter returns the value from the TSC which is
// incremented at the CPU frequency. The algorithm used requires
// the CPU frequency to be constant. Technology like speed stepping
// which has variable CPU frequency will therefore yield unpredictable,
// incorrect time estimations.
LARGE_INTEGER qpcnt;
QueryPerformanceCounter(&qpcnt);
result._ticks = qpcnt.QuadPart;
#else
static volatile LONG lastTimeGetTime = 0;
static volatile WebRtc_Word64 numWrapTimeGetTime = 0;
volatile LONG* lastTimeGetTimePtr = &lastTimeGetTime;
DWORD now = timeGetTime();
// Atomically update the last gotten time
DWORD old = InterlockedExchange(lastTimeGetTimePtr, now);
if(now < old)
{
// If now is earlier than old, there may have been a race between
// threads.
// 0x0fffffff ~3.1 days, the code will not take that long to execute
// so it must have been a wrap around.
if(old > 0xf0000000 && now < 0x0fffffff)
{
numWrapTimeGetTime++;
}
}
result._ticks = now + (numWrapTimeGetTime<<32);
#endif
#elif defined(WEBRTC_LINUX)
struct timespec ts;
#ifdef WEBRTC_CLOCK_TYPE_REALTIME
clock_gettime(CLOCK_REALTIME, &ts);
#else
clock_gettime(CLOCK_MONOTONIC, &ts);
#endif
result._ticks = 1000000000LL * static_cast<WebRtc_Word64>(ts.tv_sec) + static_cast<WebRtc_Word64>(ts.tv_nsec);
#else
struct timeval tv;
gettimeofday(&tv, NULL);
result._ticks = 1000000LL * static_cast<WebRtc_Word64>(tv.tv_sec) + static_cast<WebRtc_Word64>(tv.tv_usec);
#endif
return result;
}
inline WebRtc_Word64 TickTime::MillisecondTimestamp()
{
TickTime now = TickTime::Now();
#if _WIN32
#ifdef USE_QUERY_PERFORMANCE_COUNTER
LARGE_INTEGER qpfreq;
QueryPerformanceFrequency(&qpfreq);
return (now._ticks * 1000) / qpfreq.QuadPart;
#else
return now._ticks;
#endif
#elif WEBRTC_LINUX
return now._ticks / 1000000LL;
#else
return now._ticks / 1000LL;
#endif
}
inline WebRtc_Word64 TickTime::MicrosecondTimestamp()
{
TickTime now = TickTime::Now();
#if _WIN32
#ifdef USE_QUERY_PERFORMANCE_COUNTER
LARGE_INTEGER qpfreq;
QueryPerformanceFrequency(&qpfreq);
return (now._ticks * 1000) / (qpfreq.QuadPart/1000);
#else
return now._ticks *1000LL;
#endif
#elif WEBRTC_LINUX
return now._ticks / 1000LL;
#else
return now._ticks;
#endif
}
inline WebRtc_Word64 TickTime::Ticks() const
{
return _ticks;
}
inline WebRtc_Word64 TickTime::MillisecondsToTicks(const WebRtc_Word64 ms)
{
#if _WIN32
#ifdef USE_QUERY_PERFORMANCE_COUNTER
LARGE_INTEGER qpfreq;
QueryPerformanceFrequency(&qpfreq);
return (qpfreq.QuadPart * ms) / 1000;
#else
return ms;
#endif
#elif WEBRTC_LINUX
return ms * 1000000LL;
#else
return ms * 1000LL;
#endif
}
inline WebRtc_Word64 TickTime::TicksToMilliseconds(const WebRtc_Word64 ticks)
{
#if _WIN32
#ifdef USE_QUERY_PERFORMANCE_COUNTER
LARGE_INTEGER qpfreq;
QueryPerformanceFrequency(&qpfreq);
return (ticks * 1000) / qpfreq.QuadPart;
#else
return ticks;
#endif
#elif WEBRTC_LINUX
return ticks / 1000000LL;
#else
return ticks / 1000LL;
#endif
}
inline TickTime& TickTime::operator+=(const WebRtc_Word64& ticks)
{
_ticks += ticks;
return *this;
}
inline TickInterval::TickInterval() : _interval(0)
{
}
inline TickInterval::TickInterval(const WebRtc_Word64 interval)
: _interval(interval)
{
}
inline WebRtc_Word64 TickInterval::Milliseconds() const
{
#if _WIN32
#ifdef USE_QUERY_PERFORMANCE_COUNTER
LARGE_INTEGER qpfreq;
QueryPerformanceFrequency(&qpfreq);
return (_interval * 1000) / qpfreq.QuadPart;
#else
// _interval is in ms
return _interval;
#endif
#elif WEBRTC_LINUX
// _interval is in ns
return _interval / 1000000;
#else
// _interval is usecs
return _interval / 1000;
#endif
}
inline WebRtc_Word64 TickInterval::Microseconds() const
{
#if _WIN32
#ifdef USE_QUERY_PERFORMANCE_COUNTER
LARGE_INTEGER qpfreq;
QueryPerformanceFrequency(&qpfreq);
return (_interval * 1000000) / qpfreq.QuadPart;
#else
// _interval is in ms
return _interval *1000LL;
#endif
#elif WEBRTC_LINUX
// _interval is in ns
return _interval / 1000;
#else
// _interval is usecs
return _interval;
#endif
}
inline TickInterval& TickInterval::operator+=(const TickInterval& rhs)
{
_interval += rhs._interval;
return *this;
}
inline TickInterval& TickInterval::operator-=(const TickInterval& rhs)
{
_interval -= rhs._interval;
return *this;
}
} // namespace webrtc
#endif // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_TICK_UTIL_H_