timer.c File Reference

Include dependency graph for timer.c:

Data Structures
struct	vlc_timer

Functions
static void *	vlc_timer_thread (void *data)
int	vlc_timer_create (vlc_timer_t *id, void(*func)(void *), void *data)
	Initializes an asynchronous timer.
void	vlc_timer_destroy (vlc_timer_t timer)
	Destroys an initialized timer.
void	vlc_timer_schedule (vlc_timer_t timer, bool absolute, mtime_t value, mtime_t interval)
	Arm or disarm an initialized timer.
unsigned	vlc_timer_getoverrun (vlc_timer_t timer)
	Fetch and reset the overrun counter for a timer.

Function Documentation

int vlc_timer_create	(	vlc_timer_t *	id,
		void(*)(void *)	func,
		void *	data
	)

Initializes an asynchronous timer.

Warning

Asynchronous timers are processed from an unspecified thread. Multiple occurences of a single interval timer are serialized; they cannot run concurrently.

Parameters

id	pointer to timer to be initialized
func	function that the timer will call
data	parameter for the timer function

Returns

0 on success, a system error code otherwise.

References atomic_init, vlc_timer::data, vlc_timer::func, vlc_timer::interval, vlc_timer::lock, vlc_timer::overruns, vlc_timer::reschedule, vlc_timer::thread, unlikely, vlc_timer::value, vlc_clone(), vlc_cond_destroy(), vlc_cond_init(), vlc_mutex_destroy(), vlc_mutex_init(), VLC_THREAD_PRIORITY_INPUT, and vlc_timer_thread().

void vlc_timer_destroy

(

vlc_timer_t

timer

)

Destroys an initialized timer.

If needed, the timer is first disarmed. This function is undefined if the specified timer is not initialized.

Warning

This function must be called before the timer data can be freed and before the timer callback function can be unloaded.

Parameters

timer

timer to destroy

References vlc_timer::lock, vlc_timer::reschedule, vlc_timer::thread, vlc_cancel(), vlc_cond_destroy(), vlc_join(), and vlc_mutex_destroy().

unsigned vlc_timer_getoverrun

(

vlc_timer_t

timer

)

Fetch and reset the overrun counter for a timer.

Parameters

timer

initialized timer

Returns

the timer overrun counter, i.e. the number of times that the timer should have run but did not since the last actual run. If all is well, this is zero.

References vlc_timer::overruns.

void vlc_timer_schedule	(	vlc_timer_t	timer,
		bool	absolute,
		mtime_t	value,
		mtime_t	interval
	)

Arm or disarm an initialized timer.

This functions overrides any previous call to itself.

Note

A timer can fire later than requested due to system scheduling limitations. An interval timer can fail to trigger sometimes, either because the system is busy or suspended, or because a previous iteration of the timer is still running. See also vlc_timer_getoverrun().

Parameters

timer	initialized timer
absolute	the timer value origin is the same as mdate() if true, the timer value is relative to now if false.
value	zero to disarm the timer, otherwise the initial time to wait before firing the timer.
interval	zero to fire the timer just once, otherwise the timer repetition interval.

References vlc_timer::interval, vlc_timer::lock, mdate(), vlc_timer::reschedule, vlc_timer::value, vlc_cond_signal(), vlc_mutex_lock(), and vlc_mutex_unlock().

static void* vlc_timer_thread ( void *  data )

static

References vlc_timer::data, vlc_timer::func, vlc_timer::interval, vlc_timer::lock, mdate(), mutex_cleanup_push, vlc_timer::overruns, vlc_timer::reschedule, vlc_timer::value, vlc_cleanup_pop, vlc_cond_timedwait(), vlc_cond_wait(), vlc_mutex_lock(), vlc_mutex_unlock(), vlc_restorecancel(), and vlc_savecancel().

Referenced by vlc_timer_create().