Timers

Detailed Description

Provides support for RTOS timers.

Note

The timer service must have a priority higher than MMOSAL_TASK_PRI_HIGH. This is because tasks may yield to allow the timer service to execute. In some RTOS implementations if there are no other tasks at a higher or equal priority to the task that calls mmosal_task_yield() then the RTOS scheduler will simply select the task that called mmosal_task_yield() to run again.

Typedefs
typedef void(*	timer_callback_t) (struct mmosal_timer *timer)
	Function type definition for timer callbacks. More...

Functions
struct mmosal_timer *	mmosal_timer_create (const char *name, uint32_t timer_period_ms, bool auto_reload, void *arg, timer_callback_t callback)
	Create a new timer. More...
void	mmosal_timer_delete (struct mmosal_timer *timer)
	Delete a timer. More...
bool	mmosal_timer_start (struct mmosal_timer *timer)
	Start a timer. More...
bool	mmosal_timer_stop (struct mmosal_timer *timer)
	Stop a timer. More...
bool	mmosal_timer_change_period (struct mmosal_timer *timer, uint32_t new_period)
	Change timer period. More...
void *	mmosal_timer_get_arg (struct mmosal_timer *timer)
	Get the opaque argument associated with a given timer. More...
bool	mmosal_is_timer_active (struct mmosal_timer *timer)
	Queries the timer to determine if it running. More...

Typedef Documentation

timer_callback_t

typedef void(* timer_callback_t) (struct mmosal_timer *timer)

Function type definition for timer callbacks.

Parameters

timer

The timer that triggered the callback.

Definition at line 760 of file mmosal.h.

Function Documentation

mmosal_is_timer_active()

bool mmosal_is_timer_active

(

struct mmosal_timer *

timer

)

Queries the timer to determine if it running.

Parameters

timer

The timer to retrieve the argument from.

Returns

true if the timer is running, else false.

mmosal_timer_change_period()

bool mmosal_timer_change_period	(	struct mmosal_timer *	timer,
		uint32_t	new_period
	)

Change timer period.

Warning

May not be invoked from an ISR.

Parameters

timer	The timer to assign the new period.
new_period	Period to assign to the timer.

Returns

true if the timer period was stopped change, else false.

mmosal_timer_create()

struct mmosal_timer * mmosal_timer_create	(	const char *	name,
		uint32_t	timer_period_ms,
		bool	auto_reload,
		void *	arg,
		timer_callback_t	callback
	)

Create a new timer.

Parameters

name	The name of the timer.
timer_period_ms	The period of the timer in milliseconds.
auto_reload	If true then the timer will automatically be reloaded when it expires.
arg	Void pointer that can be used to store a value for the timer callback. Pass NULL if unused.
callback	Callback to be triggered when the timer expires.

Returns

an opaque handle to the timer, or NULL on failure.

Warning

Ensure that the timer callback function does not block or cause the calling task to be placed in a blocked state.

mmosal_timer_delete()

void mmosal_timer_delete

(

struct mmosal_timer *

timer

)

Delete a timer.

Parameters

timer

The timer to delete.

mmosal_timer_get_arg()

void * mmosal_timer_get_arg

(

struct mmosal_timer *

timer

)

Get the opaque argument associated with a given timer.

Parameters

timer

The timer to retrieve the argument from.

Returns

void pointer to the argument.

mmosal_timer_start()

bool mmosal_timer_start

(

struct mmosal_timer *

timer

)

Start a timer.

Parameters

timer

The timer to start.

Returns

true if the timer was started successfully, else false.

mmosal_timer_stop()

bool mmosal_timer_stop

(

struct mmosal_timer *

timer

)

Stop a timer.

Parameters

timer

The timer to stop.

Returns

true if the timer was stopped successfully, else false.