webrtc/talk/base/timing.cc
henrike@webrtc.org 28e2075280 Adds trunk/talk folder of revision 359 from libjingles google code to
trunk/talk


git-svn-id: http://webrtc.googlecode.com/svn/trunk@4318 4adac7df-926f-26a2-2b94-8c16560cd09d
2013-07-10 00:45:36 +00:00

130 lines
4.0 KiB
C++

/*
* libjingle
* Copyright 2008, Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include "talk/base/timing.h"
#include "talk/base/timeutils.h"
#if defined(POSIX)
#include <errno.h>
#include <math.h>
#include <sys/time.h>
#if defined(OSX)
#include <mach/mach.h>
#include <mach/clock.h>
#endif
#elif defined(WIN32)
#include <sys/timeb.h>
#include "talk/base/win32.h"
#endif
namespace talk_base {
Timing::Timing() {
#if defined(WIN32)
// This may fail, but we handle failure gracefully in the methods
// that use it (use alternative sleep method).
//
// TODO: Make it possible for user to tell if IdleWait will
// be done at lesser resolution because of this.
timer_handle_ = CreateWaitableTimer(NULL, // Security attributes.
FALSE, // Manual reset?
NULL); // Timer name.
#endif
}
Timing::~Timing() {
#if defined(WIN32)
if (timer_handle_ != NULL)
CloseHandle(timer_handle_);
#endif
}
double Timing::WallTimeNow() {
#if defined(POSIX)
struct timeval time;
gettimeofday(&time, NULL);
// Convert from second (1.0) and microsecond (1e-6).
return (static_cast<double>(time.tv_sec) +
static_cast<double>(time.tv_usec) * 1.0e-6);
#elif defined(WIN32)
struct _timeb time;
_ftime(&time);
// Convert from second (1.0) and milliseconds (1e-3).
return (static_cast<double>(time.time) +
static_cast<double>(time.millitm) * 1.0e-3);
#endif
}
double Timing::TimerNow() {
return (static_cast<double>(TimeNanos()) / kNumNanosecsPerSec);
}
double Timing::BusyWait(double period) {
double start_time = TimerNow();
while (TimerNow() - start_time < period) {
}
return TimerNow() - start_time;
}
double Timing::IdleWait(double period) {
double start_time = TimerNow();
#if defined(POSIX)
double sec_int, sec_frac = modf(period, &sec_int);
struct timespec ts;
ts.tv_sec = static_cast<time_t>(sec_int);
ts.tv_nsec = static_cast<long>(sec_frac * 1.0e9); // NOLINT
// NOTE(liulk): for the NOLINT above, long is the appropriate POSIX
// type.
// POSIX nanosleep may be interrupted by signals.
while (nanosleep(&ts, &ts) == -1 && errno == EINTR) {
}
#elif defined(WIN32)
if (timer_handle_ != NULL) {
LARGE_INTEGER due_time;
// Negative indicates relative time. The unit is 100 nanoseconds.
due_time.QuadPart = -LONGLONG(period * 1.0e7);
SetWaitableTimer(timer_handle_, &due_time, 0, NULL, NULL, TRUE);
WaitForSingleObject(timer_handle_, INFINITE);
} else {
// Still attempts to sleep with lesser resolution.
// The unit is in milliseconds.
Sleep(DWORD(period * 1.0e3));
}
#endif
return TimerNow() - start_time;
}
} // namespace talk_base