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/*
* Precise timer routines using Mach timing
*
* Copyright (c) 2003-2004, Dan Villiom Podlaski Christiansen
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*/
#include <unistd.h>
#include <stdint.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
#include <sys/time.h>
#include <mach/mach_time.h>
#include "config.h"
#include "mp_msg.h"
#include "timer.h"
/* global variables */
static double timebase_ratio;
const char timer_name[] = "Darwin accurate";
/* the core sleep function, uses floats and is used in MPlayer G2 */
static float sleep_accurate(float time_frame)
{
uint64_t deadline = time_frame / timebase_ratio + mach_absolute_time();
mach_wait_until(deadline);
return (mach_absolute_time() - deadline) * timebase_ratio;
}
/* wrapper for MPlayer G1 */
int usec_sleep(int usec_delay)
{
return sleep_accurate(usec_delay / 1e6) * 1e6;
}
/* current time in microseconds */
unsigned int GetTimer(void)
{
return (unsigned int)(uint64_t)(mach_absolute_time() * timebase_ratio * 1e6);
}
/* current time in milliseconds */
unsigned int GetTimerMS(void)
{
return (unsigned int)(uint64_t)(mach_absolute_time() * timebase_ratio * 1e3);
}
/* initialize timer, must be called at least once at start */
void InitTimer(void)
{
struct mach_timebase_info timebase;
mach_timebase_info(&timebase);
timebase_ratio = (double)timebase.numer / (double)timebase.denom
* (double)1e-9;
}
#if 0
#include <stdio.h>
int main(void) {
int i,j, r, c = 200;
long long t = 0;
InitTimer();
for (i = 0; i < c; i++) {
const int delay = rand() / (RAND_MAX / 1e5);
j = GetTimer();
#if 1
r = usec_sleep(delay);
#else
r = sleep_accurate(delay / 1e6) * 1e6;
#endif
j = (GetTimer() - j) - delay;
printf("sleep time:%8i %5i (%i)\n", delay, j, j - r);
t += j - r;
}
fprintf(stderr, "average error:\t%lli\n", t / c);
return 0;
}
#endif
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