gramps
d212d5ae2c
Absolute-deadline 1s marker (CLOCK_REALTIME clock_nanosleep, user-readable timestamp + drift per second) so a recording's real-time pace is checkable on screen. Deadline pacing mirrors game-loop/OBS canon - stackoverflow.com/questions/5441464. Build: gcc -O2 -o ticker ticker.c
38 lines
1.1 KiB
C
38 lines
1.1 KiB
C
#include <errno.h>
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#include <inttypes.h>
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#include <signal.h>
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#include <stdio.h>
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#include <time.h>
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static volatile sig_atomic_t g_run = 1;
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static void stop(int s){ (void)s; g_run = 0; }
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static double mono(void){
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struct timespec t; clock_gettime(CLOCK_MONOTONIC, &t);
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return (double)t.tv_sec + (double)t.tv_nsec/1e9;
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}
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int main(void){
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signal(SIGINT, stop); signal(SIGTERM, stop);
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struct timespec base; clock_gettime(CLOCK_REALTIME, &base);
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base.tv_nsec = 0; base.tv_sec += 1;
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double t0 = mono();
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uint64_t tick = 0;
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while (g_run){
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struct timespec dl = base;
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dl.tv_sec += (time_t)tick;
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int rc = clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &dl, NULL);
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if (rc != 0 && rc != EINTR) break;
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double now = mono();
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double drift = (now - t0 - (double)tick) * 1e3;
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struct timespec r; clock_gettime(CLOCK_REALTIME, &r);
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struct tm mv; localtime_r(&r.tv_sec, &mv);
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printf("[%05" PRIu64 "] t+%09.6fs drift %+7.2fms %02d:%02d:%02d\n",
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tick, now - t0, drift, mv.tm_hour, mv.tm_min, mv.tm_sec);
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fflush(stdout);
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tick++;
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}
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return 0;
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}
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