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/*
* Copyright 2004 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.
*/
#include <stdint.h>
#if defined(WEBRTC_POSIX)
#include <sys/time.h>
#if defined(WEBRTC_MAC)
#include <mach/mach_time.h>
#endif
#endif
#if defined(WEBRTC_WIN)
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#include <mmsystem.h>
#endif
#include "webrtc/base/checks.h"
#include "webrtc/base/timeutils.h"
#define EFFICIENT_IMPLEMENTATION 1
namespace rtc {
const uint32_t HALF = 0x80000000;
uint64_t TimeNanos() {
int64_t ticks = 0;
#if defined(WEBRTC_MAC)
static mach_timebase_info_data_t timebase;
if (timebase.denom == 0) {
// Get the timebase if this is the first time we run.
// Recommended by Apple's QA1398.
if (mach_timebase_info(&timebase) != KERN_SUCCESS) {
RTC_DCHECK(false);
}
}
// Use timebase to convert absolute time tick units into nanoseconds.
ticks = mach_absolute_time() * timebase.numer / timebase.denom;
#elif defined(WEBRTC_POSIX)
struct timespec ts;
// TODO: Do we need to handle the case when CLOCK_MONOTONIC
// is not supported?
clock_gettime(CLOCK_MONOTONIC, &ts);
ticks = kNumNanosecsPerSec * static_cast<int64_t>(ts.tv_sec) +
static_cast<int64_t>(ts.tv_nsec);
#elif defined(WEBRTC_WIN)
static volatile LONG last_timegettime = 0;
static volatile int64_t num_wrap_timegettime = 0;
volatile LONG* last_timegettime_ptr = &last_timegettime;
DWORD now = timeGetTime();
// Atomically update the last gotten time
DWORD old = InterlockedExchange(last_timegettime_ptr, 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) {
num_wrap_timegettime++;
}
}
ticks = now + (num_wrap_timegettime << 32);
// TODO: Calculate with nanosecond precision. Otherwise, we're just
// wasting a multiply and divide when doing Time() on Windows.
ticks = ticks * kNumNanosecsPerMillisec;
#endif
return ticks;
}
uint32_t Time() {
return static_cast<uint32_t>(TimeNanos() / kNumNanosecsPerMillisec);
}
uint64_t TimeMicros() {
return static_cast<uint64_t>(TimeNanos() / kNumNanosecsPerMicrosec);
}
#if defined(WEBRTC_WIN)
static const uint64_t kFileTimeToUnixTimeEpochOffset = 116444736000000000ULL;
struct timeval {
long tv_sec, tv_usec; // NOLINT
};
// Emulate POSIX gettimeofday().
// Based on breakpad/src/third_party/glog/src/utilities.cc
static int gettimeofday(struct timeval *tv, void *tz) {
// FILETIME is measured in tens of microseconds since 1601-01-01 UTC.
FILETIME ft;
GetSystemTimeAsFileTime(&ft);
LARGE_INTEGER li;
li.LowPart = ft.dwLowDateTime;
li.HighPart = ft.dwHighDateTime;
// Convert to seconds and microseconds since Unix time Epoch.
int64_t micros = (li.QuadPart - kFileTimeToUnixTimeEpochOffset) / 10;
tv->tv_sec = static_cast<long>(micros / kNumMicrosecsPerSec); // NOLINT
tv->tv_usec = static_cast<long>(micros % kNumMicrosecsPerSec); // NOLINT
return 0;
}
// Emulate POSIX gmtime_r().
static struct tm *gmtime_r(const time_t *timep, struct tm *result) {
// On Windows, gmtime is thread safe.
struct tm *tm = gmtime(timep); // NOLINT
if (tm == NULL) {
return NULL;
}
*result = *tm;
return result;
}
#endif // WEBRTC_WIN
void CurrentTmTime(struct tm *tm, int *microseconds) {
struct timeval timeval;
if (gettimeofday(&timeval, NULL) < 0) {
// Incredibly unlikely code path.
timeval.tv_sec = timeval.tv_usec = 0;
}
time_t secs = timeval.tv_sec;
gmtime_r(&secs, tm);
*microseconds = timeval.tv_usec;
}
uint32_t TimeAfter(int32_t elapsed) {
RTC_DCHECK_GE(elapsed, 0);
RTC_DCHECK_LT(static_cast<uint32_t>(elapsed), HALF);
return Time() + elapsed;
}
bool TimeIsBetween(uint32_t earlier, uint32_t middle, uint32_t later) {
if (earlier <= later) {
return ((earlier <= middle) && (middle <= later));
} else {
return !((later < middle) && (middle < earlier));
}
}
bool TimeIsLaterOrEqual(uint32_t earlier, uint32_t later) {
#if EFFICIENT_IMPLEMENTATION
int32_t diff = later - earlier;
return (diff >= 0 && static_cast<uint32_t>(diff) < HALF);
#else
const bool later_or_equal = TimeIsBetween(earlier, later, earlier + HALF);
return later_or_equal;
#endif
}
bool TimeIsLater(uint32_t earlier, uint32_t later) {
#if EFFICIENT_IMPLEMENTATION
int32_t diff = later - earlier;
return (diff > 0 && static_cast<uint32_t>(diff) < HALF);
#else
const bool earlier_or_equal = TimeIsBetween(later, earlier, later + HALF);
return !earlier_or_equal;
#endif
}
int32_t TimeDiff(uint32_t later, uint32_t earlier) {
#if EFFICIENT_IMPLEMENTATION
return later - earlier;
#else
const bool later_or_equal = TimeIsBetween(earlier, later, earlier + HALF);
if (later_or_equal) {
if (earlier <= later) {
return static_cast<long>(later - earlier);
} else {
return static_cast<long>(later + (UINT32_MAX - earlier) + 1);
}
} else {
if (later <= earlier) {
return -static_cast<long>(earlier - later);
} else {
return -static_cast<long>(earlier + (UINT32_MAX - later) + 1);
}
}
#endif
}
TimestampWrapAroundHandler::TimestampWrapAroundHandler()
: last_ts_(0), num_wrap_(0) {}
int64_t TimestampWrapAroundHandler::Unwrap(uint32_t ts) {
if (ts < last_ts_) {
if (last_ts_ > 0xf0000000 && ts < 0x0fffffff) {
++num_wrap_;
}
}
last_ts_ = ts;
int64_t unwrapped_ts = ts + (num_wrap_ << 32);
return unwrapped_ts;
}
} // namespace rtc
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