timer-stop logic

[M1cha]

I was looking at these 4 lines:
https://github.com/troglobit/libuev/blob/a334d23/src/uev.c#L381

if (!w->u.t.period)
	w->u.t.timeout = 0;
if (!w->u.t.timeout)
	uev_timer_stop(w);

To me this looks like when there's no initial timeout, and only a periodic timer, the timer just gets stopped after the first expiration.
Is that a bug or intended behavior?

[troglobit]

That is intended behavior, not really well documented though. Setting timeout to zero disarms the timer. So for a periodic timer you have to set the initial delay as well.

The uev_timer_init() function calls uev_timer_set() (below):

libuev/src/timer.c

Lines 93 to 105 in a334d23

	/**
	* Reset a timer
	* @param w Watcher to reset
	* @param timeout Timeout in milliseconds before @param cb is called, zero disarms timer
	* @param period For periodic timers this is the period time that @param timeout is reset to
	*
	* Note, the @param timeout value must be non-zero. Setting it to zero
	* will disarm the timer. This is the underlying Linux function @func
	* timerfd_settimer() which has this behavior.
	*
	* @return POSIX OK(0) or non-zero with @param errno set on error.
	*/
	int uev_timer_set(uev_t *w, int timeout, int period)

[M1cha]

That part is not true though:

This is the underlying Linux function @func timerfd_settimer() which has this behavior. 

https://linux.die.net/man/2/timerfd_settime

Setting either field of new_value.it_value to a nonzero value arms the timer. Setting both fields of new_value.it_value to zero disarms the timer.

[M1cha]

forget what I said. I didn't read properly and thought they were talking about "both" in the sense of "it_interval" and "it_value"