mpv/osdep/timer.c

85 lines
2.0 KiB
C

/*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* mpv is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <pthread.h>
#include "timer.h"
#include "common/msg.h"
static uint64_t raw_time_offset;
pthread_once_t timer_init_once = PTHREAD_ONCE_INIT;
static void do_timer_init(void)
{
mp_raw_time_init();
srand(mp_raw_time_us());
raw_time_offset = mp_raw_time_us();
// Arbitrary additional offset to avoid confusing relative/absolute times.
// Also,we rule that the timer never returns 0 (so default-initialized
// time values will be always in the past).
raw_time_offset -= 10000000;
}
void mp_time_init(void)
{
pthread_once(&timer_init_once, do_timer_init);
}
int64_t mp_time_us(void)
{
return mp_raw_time_us() - raw_time_offset;
}
double mp_time_sec(void)
{
return mp_time_us() / (double)(1000 * 1000);
}
int64_t mp_time_relative_us(int64_t *t)
{
int64_t r = 0;
int64_t now = mp_time_us();
if (*t)
r = now - *t;
*t = now;
return r;
}
#if 0
#include <stdio.h>
int main(void) {
int c = 200;
int64_t j, r, t = 0;
mp_time_init();
for (int i = 0; i < c; i++) {
const int delay = rand() / (RAND_MAX / 1e5);
r = mp_time_us();
mp_sleep_us(delay);
j = (mp_time_us() - r) - delay;
printf("sleep time: sleep=%8i err=%5i\n", delay, (int)j);
t += j;
}
fprintf(stderr, "average error:\t%i\n", (int)(t / c));
return 0;
}
#endif