Asynchronous/threaded timers

Collaboration diagram for Asynchronous/threaded timers:

Macros
#define	VLC_TIMER_DISARM   (0)
#define	VLC_TIMER_FIRE_ONCE   (0)

Typedefs
typedef struct vlc_timer *	vlc_timer_t
	Threaded timer handle.

Functions
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, vlc_tick_t value, vlc_tick_t interval)
	Arms or disarms an initialized timer.
static void	vlc_timer_disarm (vlc_timer_t timer)
static void	vlc_timer_schedule_asap (vlc_timer_t timer, vlc_tick_t interval)
unsigned	vlc_timer_getoverrun (vlc_timer_t timer)
	Fetches and resets the overrun counter for a timer.

Detailed Description

Macro Definition Documentation

VLC_TIMER_DISARM

#define VLC_TIMER_DISARM   (0)

VLC_TIMER_FIRE_ONCE

#define VLC_TIMER_FIRE_ONCE   (0)

Typedef Documentation

vlc_timer_t

typedef struct vlc_timer* vlc_timer_t

Threaded timer handle.

Function Documentation

vlc_timer_create()

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

Initializes an asynchronous timer.

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.

Warning

Asynchronous timers are processed from an unspecified thread.

Note

Multiple occurrences of a single interval timer are serialized: they cannot run concurrently.

References vlc_timer::data, vlc_timer::func, vlc_timer::hev, vlc_timer::htimer, vlc_timer::interval, vlc_timer::live, vlc_timer::lock, vlc_timer::overruns, vlc_timer::quit, vlc_timer::reschedule, vlc_timer::t, vlc_timer::thread, vlc_timer::tid, timer_callback(), unlikely, vlc_timer::value, vlc_clone(), vlc_cond_init(), vlc_mutex_init(), vlc_once_begin, vlc_once_complete(), vlc_timer_do(), and vlc_timer_thread().

vlc_timer_destroy()

void vlc_timer_destroy

(

vlc_timer_t

timer

)

Destroys an initialized timer.

If needed, the timer is first disarmed. Behaviour 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 unmapped/unloaded.

Parameters

timer

timer to destroy

References vlc_timer::hev, vlc_timer::htimer, vlc_timer::live, vlc_timer::lock, vlc_timer::quit, vlc_timer::reschedule, vlc_timer::t, vlc_timer::thread, vlc_timer::tid, vlc_cond_signal(), vlc_join(), vlc_mutex_lock(), and vlc_mutex_unlock().

vlc_timer_disarm()

static void vlc_timer_disarm ( vlc_timer_t  timer )

inlinestatic

References VLC_TIMER_DISARM, and vlc_timer_schedule().

vlc_timer_getoverrun()

unsigned vlc_timer_getoverrun

(

vlc_timer_t

timer

)

Fetches and resets the overrun counter for a timer.

This functions returns the number of times that the interval timer should have fired, but the callback was not invoked due to scheduling problems. The call resets the counter to zero.

Parameters

timer

initialized timer

Returns

the timer overrun counter (typically zero)

References vlc_timer::overruns.

vlc_timer_schedule()

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

Arms or disarms 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 vlc_tick_now() 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::hev, vlc_timer::htimer, vlc_timer::interval, vlc_timer::lock, MS_FROM_VLC_TICK, MSFTIME_FROM_VLC_TICK, vlc_timer::reschedule, vlc_timer::t, unlikely, vlc_timer::value, vlc_cond_signal(), vlc_mutex_lock(), vlc_mutex_unlock(), vlc_tick_now(), VLC_TIMER_DISARM, and VLC_TIMER_FIRE_ONCE.

Referenced by vlc_timer_disarm(), and vlc_timer_schedule_asap().

vlc_timer_schedule_asap()

static void vlc_timer_schedule_asap ( vlc_timer_t  timer, vlc_tick_t  interval  )

inlinestatic

References vlc_timer_schedule().