libev - example: timer

#include <ev.h> ev_timer timeout_watcher; // callback for timeout static void timeout_cb(EV_P_ struct ev_timer* w, int revents) { puts("timeout"); } int main() { // use the default event loop struct ev_loop* loop = ev_default_loop(0); // initialize an timer watcher // the timeout event will occur after 1sec, and repeat every 3sec. ev_timer_init(&timeout_watcher, timeout_cb, 1, 3); ev_timer_start(loop, &timeout_watcher); // event loop ev_run(loop, 0); return 0; }

ev_timer_init(ev_timer*, callback, ev_tstamp after, ev_tstamp repeat)

• configure the timer to trigger after after seconds.
• If repeat is 0, then it will automatically be stopped once the timeout is reached.
• If repeat is positive, then the timer will automatically be configured to trigger again repeat seconds later, again and again.

#include <ev.h> #include <stdio.h> ev_timer timeout_watcher; // callback for timeout static void timeout_cb(EV_P_ struct ev_timer* timer, int revents) { // reduce repeat time interval by 1 seconds. timer->repeat -= 1.0; printf("timeout - repeat: %lf\n", timer->repeat); // repeat ev_timer_again(loop, &timeout_watcher); } int main() { // use the default event loop struct ev_loop* loop = ev_default_loop(0); // initialize an timer watcher ev_timer_init(&timeout_watcher, timeout_cb, 5.0, 5.0); ev_timer_start(loop, &timeout_watcher); // event loop ev_run(loop, 0); return 0; }

ev_timer_again(loop, ev_timer*)

• This will act as if the timer timed out and restart it again if it is repeating.