mpv/osdep/timer.c

158 lines
4.1 KiB
C
Raw Normal View History

/*
* 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 <time.h>
#include <unistd.h>
#include <sys/time.h>
#include <limits.h>
#include <assert.h>
#include "common/common.h"
#include "common/msg.h"
#include "timer.h"
static uint64_t raw_time_offset;
2015-05-01 19:17:56 +00:00
static 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 -= MP_START_TIME;
}
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;
}
int64_t mp_add_timeout(int64_t time_us, double timeout_sec)
{
assert(time_us > 0); // mp_time_us() returns strictly positive values
double t = MPCLAMP(timeout_sec * (1000 * 1000), -0x1p63, 0x1p63);
int64_t ti = t == 0x1p63 ? INT64_MAX : (int64_t)t;
if (ti > INT64_MAX - time_us)
return INT64_MAX;
if (ti <= -time_us)
return 1;
return time_us + ti;
}
static void get_realtime(struct timespec *out_ts)
{
#if defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0
clock_gettime(CLOCK_REALTIME, out_ts);
#else
// OSX
struct timeval tv;
gettimeofday(&tv, NULL);
out_ts->tv_sec = tv.tv_sec;
out_ts->tv_nsec = tv.tv_usec * 1000UL;
#endif
}
struct timespec mp_time_us_to_timespec(int64_t time_us)
{
struct timespec ts;
get_realtime(&ts);
// We don't know what time source mp_time_us() uses, but usually it's not
// CLOCK_REALTIME - so we have to remap the times.
int64_t unow = mp_time_us();
int64_t diff_us = time_us - unow;
int64_t diff_secs = diff_us / (1000L * 1000L);
long diff_nsecs = (diff_us - diff_secs * (1000L * 1000L)) * 1000L;
if (diff_nsecs < 0) {
diff_secs -= 1;
diff_nsecs += 1000000000L;
}
if (diff_nsecs + ts.tv_nsec >= 1000000000UL) {
diff_secs += 1;
diff_nsecs -= 1000000000UL;
}
// OSX can't deal with large timeouts. Also handles tv_sec/time_t overflows.
diff_secs = MPMIN(diff_secs, 10000000);
ts.tv_sec += diff_secs;
ts.tv_nsec += diff_nsecs;
return ts;
}
struct timespec mp_rel_time_to_timespec(double timeout_sec)
{
return mp_time_us_to_timespec(mp_add_timeout(mp_time_us(), timeout_sec));
}
#if 0
#include <stdio.h>
#include "threads.h"
#define TEST_SLEEP 1
int main(void) {
int c = 2000000;
int64_t j, r, t = 0;
pthread_mutex_t mtx;
pthread_mutex_init(&mtx, NULL);
pthread_cond_t cnd;
pthread_cond_init(&cnd, NULL);
mp_time_init();
for (int i = 0; i < c; i++) {
const int delay = rand() / (RAND_MAX / 1e5);
r = mp_time_us();
#if TEST_SLEEP
mp_sleep_us(delay);
#else
struct timespec ts = mp_time_us_to_timespec(r + delay);
pthread_cond_timedwait(&cnd, &mtx, &ts);
#endif
j = (mp_time_us() - r) - delay;
printf("sleep time: t=%"PRId64" sleep=%8i err=%5i\n", r, delay, (int)j);
t += j;
}
fprintf(stderr, "average error:\t%i\n", (int)(t / c));
return 0;
}
#endif