app_scheduler.h File Reference

Detailed Description

Application scheduler library. Allows scheduling of multiple application tasks concurrently.

Note

Unlike most services, this library is safe to be used from fast interrupt execution context

Definition in file app_scheduler.h.

Go to the source code of this file.

Typedefs
typedef uint32_t(*	task_cb_f) ()
	Task callback to be registered. More...

Functions
void	App_Scheduler_init (void)
	Initialize scheduler. More...
app_scheduler_res_e	App_Scheduler_addTask_execTime (task_cb_f cb, uint32_t delay_ms, uint32_t exec_time_us)
	Add a task. More...
app_scheduler_res_e	App_Scheduler_cancelTask (task_cb_f cb)
	Cancel a task. More...

Enumerations
enum	app_scheduler_res_e {   APP_SCHEDULER_RES_OK = 0, APP_SCHEDULER_RES_NO_MORE_TASK = 1, APP_SCHEDULER_RES_UNKNOWN_TASK = 2, APP_SCHEDULER_RES_UNINITIALIZED = 3,   APP_SCHEDULER_RES_TOO_LONG_EXECUTION_TIME = 4, APP_SCHEDULER_RES_TOO_SHORT_EXECUTION_TIME = 5 }
	List of return code. More...

Macros
#define	APP_SCHEDULER_STOP_TASK   ((uint32_t)(-1))
	Value to return from task to remove it. More...
#define	APP_SCHEDULER_SCHEDULE_ASAP   (0)
	Value to return from task or as initial time to be executed ASAP. More...

Typedef Documentation

task_cb_f

typedef uint32_t(* task_cb_f) ()

Task callback to be registered.

Returns

Delay before being executed again in ms

Note

Return value in ms is aligned on system coarse timesatmp boundaries that has a 1/128s granularity. So asking 3 or 7 ms will result in same scheduling. If a better accuracy is needed, hardware timer must be used

Definition at line 32 of file app_scheduler.h.

Function Documentation

App_Scheduler_addTask_execTime()

app_scheduler_res_e App_Scheduler_addTask_execTime	(	task_cb_f	cb,
		uint32_t	delay_ms,
		uint32_t	exec_time_us
	)

Add a task.

Example on use:

static uint32_t periodic_task_50ms()
{
    ...
    return 50;
}
 
static uint32_t periodic_task_500ms()
{
    ...
    return 500;
}
 
void App_init(const app_global_functions_t * functions)
{
    // Launch two periodic task with different period
    App_Scheduler_addTask_execTime(periodic_task_50ms, APP_SCHEDULER_SCHEDULE_ASAP, 10);
    App_Scheduler_addTask_execTime(periodic_task_500ms, APP_SCHEDULER_SCHEDULE_ASAP, 10);
    ...
    // Start the stack
    lib_state->startStack();
}

Parameters

cb	Callback to be called from main periodic task. Same cb can only be added once. Calling this function with an already registered cb will update the next scheduled time.
delay_ms	delay in ms to be scheduled (0 to be scheduled asap)
exec_time_us	Maximum execution time required for the task to be executed

Returns

True if able to add, false otherwise

Examples

appconfig/app.c, basic_interrupt/app.c, blink/app.c, custom_app/app.c, nfc/app.c, positioning_app/app.c, ruuvi_evk/app.c, scheduler/app.c, and shared_data/app.c.

App_Scheduler_cancelTask()

app_scheduler_res_e App_Scheduler_cancelTask

(

task_cb_f

cb

)

Cancel a task.

Parameters

cb	Callback already registered from App_Scheduler_addTask.

Returns

True if able to cancel, false otherwise (not existing)

Examples

ruuvi_evk/app.c, and scheduler/app.c.

App_Scheduler_init()

void App_Scheduler_init

(

void

)

Initialize scheduler.

Note

If App scheduler is enabled in app, App_Scheduler_init is automatically called before App_init

If App scheduler is used in application, the periodicWork offered by system library MUST NOT be used outside of this module

Enumeration Type Documentation

app_scheduler_res_e

enum app_scheduler_res_e

List of return code.

Enumerator
APP_SCHEDULER_RES_OK	Operation is successful
APP_SCHEDULER_RES_NO_MORE_TASK	No more tasks available
APP_SCHEDULER_RES_UNKNOWN_TASK	Trying to cancel a task that doesn't exist
APP_SCHEDULER_RES_UNINITIALIZED	Using the library without previous initialization
APP_SCHEDULER_RES_TOO_LONG_EXECUTION_TIME	Requested time is too long
APP_SCHEDULER_RES_TOO_SHORT_EXECUTION_TIME	Requested time is too short

Definition at line 47 of file app_scheduler.h.

{
    APP_SCHEDULER_RES_OK = 0,
    APP_SCHEDULER_RES_NO_MORE_TASK = 1,
    APP_SCHEDULER_RES_UNKNOWN_TASK = 2,
    APP_SCHEDULER_RES_UNINITIALIZED = 3,
    APP_SCHEDULER_RES_TOO_LONG_EXECUTION_TIME = 4,
    APP_SCHEDULER_RES_TOO_SHORT_EXECUTION_TIME = 5,
} app_scheduler_res_e;

Macro Definition Documentation

APP_SCHEDULER_SCHEDULE_ASAP

#define APP_SCHEDULER_SCHEDULE_ASAP   (0)

Value to return from task or as initial time to be executed ASAP.

Examples

basic_interrupt/app.c, blink/app.c, custom_app/app.c, nfc/app.c, positioning_app/app.c, ruuvi_evk/app.c, and scheduler/app.c.

Definition at line 42 of file app_scheduler.h.

APP_SCHEDULER_STOP_TASK

#define APP_SCHEDULER_STOP_TASK   ((uint32_t)(-1))

Value to return from task to remove it.

Examples

nfc/app.c, positioning_app/app.c, scheduler/app.c, and shared_data/app.c.

Definition at line 37 of file app_scheduler.h.