c - ev_timer callback is called earlier than it should be -


i have problem ev_timer of libev, please @ code below:

static void timeout_cb(struct ev_loop *loop, ev_timer *timer, int revent) {     printf("got timeout event, current time %s\n", get_current_time()); }  int main(int argc, char *argv[]) {     struct ev_loop *loop = ev_loop_new(0);     ev_timer_init(&timer, timeout_cb, 5.0, 0.0);     ev_timer_start(loop, &timer);     ev_run(loop, evrun_nowait);  // callback should not called     ev_timer_stop(loop, &timer); // stop timer     sleep(5);  // sleep 5 seconds, 5 timer's timeout value     // restart timer     ev_timer_init(&timer, timeout_cb, 5.0, 0.0);     ev_timer_start(loop, &timer);     printf("timer start at: %s\n", get_current_time());     printf("timer remaining: %f\n", ev_timer_remaining(loop, &timer));     ev_run(loop, evrun_nowait);     return 0; }

the output is:

timer start at: 14:53:49:137 timer remaining: 5.0000 got timeout event, current time 14:53:49:137

this strange, because after restart timer timer trigger immediately, should 5 second later. found reason sleep(5). change sleep(4) timer callback not called. i'm confused liebev's timer functionality. have misunderstand timer? , how let timer callback called after timeout elapse after timer restart?

i don't claim expert in libev, found using ev_suspend(loop) , ev_resume(loop) prevent behaviour seeing. man page:

ev_suspend (loop) ev_resume (loop)     these 2 functions suspend , resume event loop, use when     loop not used while , timeouts should not     processed.

e.g.:

ev_run(loop, evrun_nowait);  // callback should not called ev_timer_stop(loop, &timer); // stop timer ev_suspend(loop); // suspend timer processing sleep(5);  // sleep 5 seconds, 5 timer's timeout value ev_resume(loop); // resume timer processing // restart timer ev_timer_init(&timer, timeout_cb, 5.0, 0.0); ev_timer_start(loop, &timer);

also found possible solution use ev_timer_again() instead of ev_timer_start() prevents behaviour reported.

e.g.:

ev_timer_stop(loop, &timer); // stop timer sleep(5);  // sleep 5 seconds, 5 timer's timeout value // restart timer ev_timer_again(loop, &timer);

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