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mpv/osdep/timer.c
wm4 c6166ff448 timer: init only once
This avoids trouble if another mpv instance is initialized in the same
process.

Since timeBeginPeriod/timeEndPeriod are hereby not easily matched
anymore, use an atexit() handler to call timeEndPeriod, so that we
can be sure these calls are matched, even if we allow multiple
initializations later when introducing the client API.
2014-02-10 01:12:34 +01:00

74 lines
1.8 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"
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);
}
#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