Event Scheduling#

Scheduling events for future execution.

See Event Scheduling for documentation. These macros implement an event abstraction that allows the application to schedule code to run after a specified time interval. An event consists of a procedure to be called at some point in the future and a control object that determines which procedure should be called. Events are also useful when an ISR needs to initiate an action that should run outside the ISR context.

See event.h for source code.

Note that, while not required, it is recommended that the event-handling procedure explicitly define the recurrence of the next event, either by rescheduling via some kind of emberEventControlSetDelayXX() call or by deactivating via a call to emberEventControlSetInactive().

When the handler does not explicitly reschedule or cancel the event, the default behavior of the event control system is to keep the event immediately active as if the handler function had called emberEventControlSetActive(someEvent) or emberEventControlSetDelayMS(someEvent, 0).

The base time units for events are ticks. A tick equals 1 ms on every platform supported by Connect. Note, however, that the accuracy of the base tick depends on the timer source, which by default is the LF RC oscillator on EFR32 platforms.

Furthermore, the scheduled delay is the minimum delay. If emberRunEvents() or emberRunTask() are not called frequently enough, the actual delay may be longer than the scheduled delay.

Additionally, the APIs for quarter second and minute delays (emberEventControlSetDelayQS() and emberEventControlSetDelayMinutes()) use "binary" units. One quarter second is 256 ticks and one minute is 65536 ticks. These APIs are therefore doesn't actually mean a quarter of second or a minute on platforms supported by Connect.

However, in the future, Connect support might become available on platforms where one tick is not exactly 1 ms. For example, on the EM357 SoC, 1 s is 1024 ticks, so each tick is 1000 / 1024 = ~0.98 milliseconds. If you need platform independent accurate delays, use the macros ::MILLISECOND_TICKS_PER_SECOND and ::MILLISECOND_TICKS_PER_MINUTE. For example, calling emberEventControlSetDelayMS(someEvent, 3 * MILLISECOND_TICKS_PER_MINUTE) will delay for 3 minutes on any platform.

The following are brief usage examples. 

EmberEventControl delayEvent;
EmberEventControl signalEvent;
EmberEventControl periodicEvent;

void delayEventHandler(void)
{
  // Disable this event until its next use.
  emberEventControlSetInactive(delayEvent);
}

void signalEventHandler(void)
{
  // Disable this event until its next use.
  emberEventControlSetInactive(signalEvent);

  // Sometimes an action has to occur 100 ms later.
  if (somethingIsExpected)
    emberEventControlSetDelayMS(delayEvent, 100);
}

void periodicEventHandler(void)
{
  emberEventControlSetDelayQS(periodicEvent, 4);
}

void someIsr(void)
{
  // Set the signal event to run at the first opportunity.
  emberEventControlSetActive(signalEvent);
}

// Put the controls and handlers in an array.  They will be run in
// this order (this is usually generated)
EmberEventData events[] =
 {
   { &delayEvent,    delayEventHandler },
   { &signalEvent,   signalEentHandler },
   { &periodicEvent, periodicEventHandler },
   { NULL, NULL }                            // terminator
 };

void main(void)
{
  // Cause the periodic event to occur once a second.
  emberEventControlSetDelayQS(periodicEvent, 4);

  while (TRUE) {
    emberRunEvents(events);
  }
}

Functions#

void
sli_event_control_set_active(EmberEventControl *event)

Set EmberEventControl to run at the next available opportunity.

void
emEventControlSetDelayMS(EmberEventControl *event, uint32_t delay)

Set EmberEventControl to run some milliseconds in the future.

uint32_t
emEventControlGetRemainingMS(EmberEventControl *event)

Check when the event is scheduled to run.

void
emberRunEvents(EmberEventData *events)

Start an event handler if anything is scheduled when this function is called.

void
emberRunTask(EmberTaskId taskid)

Start an event handler if there is anything scheduled at the moment this function is called.

uint32_t
emberMsToNextEvent(EmberEventData *events, uint32_t maxMs)

Check when the next event is scheduled to run.

uint32_t
emberMsToNextEventExtended(EmberEventData *events, uint32_t maxMs, uint8_t *returnIndex)

Check when the next event is scheduled to run.

uint32_t
emberMsToNextStackEvent(void)

Check when the next stack event is scheduled to run.

EmberTaskId
emberTaskInit(EmberEventData *events)

Initialize a task for managing events and processor idling state.

bool
emberMarkTaskIdle(EmberTaskId taskid)

Try to idle the CPU, unless any events in any tasks are pending.

void
emTaskEnableIdling(bool allow)

Enable or disable idling.

void
emMarkTaskActive(EmberTaskId taskid)

Calling it indicates that a task has something to do, so it should prevent the CPU from idling until emberMarkTaskIdle is next called on this task.

Macros#

#define
__EVENT_H__
#define
EMBER_TASK_COUNT (3)

The number of event tasks that can be used to schedule and run events. Connect stack requires one, while another is used for Application Framework events.

#define
emberEventControlSetInactive (control)

Set EmberEventControl as inactive (no pending event).

#define
emberEventControlGetActive (control)

Check whether EmberEventControl is currently active. An event is considered active if it is set to run some time in the future (activated by emberEventControlSetActive(), emberEventControlSetDelayMS() or any other emberEventControlSetDelay* functions)

#define
emberEventControlSetActive (control)

Set EmberEventControl to run at the next available opportunity.

#define
EMBER_MAX_EVENT_CONTROL_DELAY_MS (HALF_MAX_INT32U_VALUE - 1)

The maximum delay that may be passed to emberEventControlSetDelayMS().

#define
emberEventControlSetDelayMS (control, delay)

Set EmberEventControl to run some milliseconds in the future.

#define
EMBER_MAX_EVENT_CONTROL_DELAY_QS (EMBER_MAX_EVENT_CONTROL_DELAY_MS >> 8)

The maximum delay that may be passed to emberEventControlSetDelayQS().

#define
emberEventControlSetDelayQS (control, delay)

Set EmberEventControl to run some quarter seconds in the future.

#define
EMBER_MAX_EVENT_CONTROL_DELAY_MINUTES (EMBER_MAX_EVENT_CONTROL_DELAY_MS >> 16)

The maximum delay that may be passed to emberEventControlSetDelayMinutes().

#define
emberEventControlSetDelayMinutes (control, delay)

Set EmberEventControl to run some minutes in the future.

#define
emberEventControlGetRemainingMS (control)

Check when the event is scheduled to run.

#define
emberTaskEnableIdling (allow)

Enable or disable idling.

#define
emberMarkTaskActive (taskid)

Calling it indicates that a task has something to do, so it should prevent the CPU from idling until emberMarkTaskIdle is next called on this task.

Function Documentation#

sli_event_control_set_active#

void sli_event_control_set_active (EmberEventControl * event)

Set EmberEventControl to run at the next available opportunity.

Parameters
[in]event

Pointer to the control of the event to set active

Warnings


Definition at line 224 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emEventControlSetDelayMS#

void emEventControlSetDelayMS (EmberEventControl * event, uint32_t delay)

Set EmberEventControl to run some milliseconds in the future.

Parameters
[in]event

Pointer to the control of the event to run.

[in]delay

The delay in milliseconds. Must be less than EMBER_MAX_EVENT_CONTROL_DELAY_MS

Warnings


Definition at line 250 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emEventControlGetRemainingMS#

uint32_t emEventControlGetRemainingMS (EmberEventControl * event)

Check when the event is scheduled to run.

Parameters
[in]event

Pointer to the control of the event in question.

Returns

  • Return the amount of milliseconds remaining before the event is scheduled to run. If the event is inactive, MAX_INT32U_VALUE is returned.

Warnings


Definition at line 303 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberRunEvents#

void emberRunEvents (EmberEventData * events)

Start an event handler if anything is scheduled when this function is called.

Parameters
[in]events

Pointer to the array of events.

An application typically creates an array of events along with their handlers. This function should be called in the main loop to run those events. Warnings


Definition at line 317 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberRunTask#

void emberRunTask (EmberTaskId taskid)

Start an event handler if there is anything scheduled at the moment this function is called.

Parameters
N/Ataskid

If an application has initialized a task via emberTaskInit(), to run the events associated with that task, it should call emberRunTask() instead of emberRunEvents().

Warnings

  • This is normally handled by the main plugin.


Definition at line 330 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberMsToNextEvent#

uint32_t emberMsToNextEvent (EmberEventData * events, uint32_t maxMs)

Check when the next event is scheduled to run.

Parameters
[in]events

An array of events to check.

[in]maxMs

If no event is scheduled before maxMs, maxMs will be returned

Returns

  • Returns the number of milliseconds before the next event is scheduled to expire, or maxMs if no event is scheduled to expire within that time.

Note

  • If any events are modified within an interrupt, to guarantee the accuracy of this API, it must be called with interrupts disabled.

See Also


Definition at line 345 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberMsToNextEventExtended#

uint32_t emberMsToNextEventExtended (EmberEventData * events, uint32_t maxMs, uint8_t * returnIndex)

Check when the next event is scheduled to run.

Parameters
[in]events

An array of events to check.

[in]maxMs

If no event is scheduled before maxMs, maxMs will be returned

[out]returnIndex

If not NULL pointer was passed, the index of the next event will be returned here, or 0xFF if no event is scheduled before maxMs.

Returns

  • Returns the number of milliseconds before the next event is scheduled to expire, or maxMs if no event is scheduled to expire within that time.

Note

  • If any events are modified within an interrupt, to guarantee the accuracy of this API, it must be called with interrupts disabled.

See Also


Definition at line 363 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberMsToNextStackEvent#

uint32_t emberMsToNextStackEvent (void )

Check when the next stack event is scheduled to run.

Parameters
N/A

Returns

  • Returns the number of milliseconds before the next stack event is scheduled to run.


Definition at line 371 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberTaskInit#

EmberTaskId emberTaskInit (EmberEventData * events)

Initialize a task for managing events and processor idling state.

Parameters
[in]events

Pointer to the array of events to manage

Returns

  • Returns the EmberTaskId which represents the newly created task.

Note

  • After the task is created emberRunTask() should be called periodically.


Definition at line 381 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberMarkTaskIdle#

bool emberMarkTaskIdle (EmberTaskId taskid)

Try to idle the CPU, unless any events in any tasks are pending.

Parameters
[in]taskid

the task which should handle the idling.

Returns

  • Returns true if the processor was idled false if idling wasn't permitted because a task has something to do.

Note

  • This API should always be called with interrupts disabled. It will forcibly re-enable interrupts before returning.


Definition at line 393 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emTaskEnableIdling#

void emTaskEnableIdling (bool allow)

Enable or disable idling.

Parameters
[in]allow

Setting it to true will enable, while setting it to false will disable idling.

Warnings


Definition at line 409 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emMarkTaskActive#

void emMarkTaskActive (EmberTaskId taskid)

Calling it indicates that a task has something to do, so it should prevent the CPU from idling until emberMarkTaskIdle is next called on this task.

Parameters
[in]taskid

The task to mark active.

Warnings


Definition at line 424 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

Macro Definition Documentation#

__EVENT_H__#

#define __EVENT_H__

Definition at line 179 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

EMBER_TASK_COUNT#

#define EMBER_TASK_COUNT
Value:
(3)

The number of event tasks that can be used to schedule and run events. Connect stack requires one, while another is used for Application Framework events.


Definition at line 186 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberEventControlSetInactive#

#define emberEventControlSetInactive
Value:
(control)

Set EmberEventControl as inactive (no pending event).


Definition at line 193 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberEventControlGetActive#

#define emberEventControlGetActive
Value:
(control)

Check whether EmberEventControl is currently active. An event is considered active if it is set to run some time in the future (activated by emberEventControlSetActive(), emberEventControlSetDelayMS() or any other emberEventControlSetDelay* functions)

Returns

  • Returns true if the event is active false otherwise


Definition at line 207 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberEventControlSetActive#

#define emberEventControlSetActive
Value:
(control)

Set EmberEventControl to run at the next available opportunity.


Definition at line 216 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

EMBER_MAX_EVENT_CONTROL_DELAY_MS#

#define EMBER_MAX_EVENT_CONTROL_DELAY_MS
Value:
(HALF_MAX_INT32U_VALUE - 1)

The maximum delay that may be passed to emberEventControlSetDelayMS().


Definition at line 230 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberEventControlSetDelayMS#

#define emberEventControlSetDelayMS
Value:
(control, delay)

Set EmberEventControl to run some milliseconds in the future.


Definition at line 239 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

EMBER_MAX_EVENT_CONTROL_DELAY_QS#

#define EMBER_MAX_EVENT_CONTROL_DELAY_QS
Value:
(EMBER_MAX_EVENT_CONTROL_DELAY_MS >> 8)

The maximum delay that may be passed to emberEventControlSetDelayQS().


Definition at line 255 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberEventControlSetDelayQS#

#define emberEventControlSetDelayQS
Value:
(control, delay)

Set EmberEventControl to run some quarter seconds in the future.

Warnings


Definition at line 266 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

EMBER_MAX_EVENT_CONTROL_DELAY_MINUTES#

#define EMBER_MAX_EVENT_CONTROL_DELAY_MINUTES
Value:
(EMBER_MAX_EVENT_CONTROL_DELAY_MS >> 16)

The maximum delay that may be passed to emberEventControlSetDelayMinutes().


Definition at line 272 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberEventControlSetDelayMinutes#

#define emberEventControlSetDelayMinutes
Value:
(control, delay)

Set EmberEventControl to run some minutes in the future.


Definition at line 281 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberEventControlGetRemainingMS#

#define emberEventControlGetRemainingMS
Value:
(control)

Check when the event is scheduled to run.

Returns

  • Returns the amount of milliseconds remaining before the event is scheduled to run. If the event is inactive, MAX_INT32U_VALUE is returned.


Definition at line 291 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberTaskEnableIdling#

#define emberTaskEnableIdling
Value:
(allow)

Enable or disable idling.


Definition at line 402 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h

emberMarkTaskActive#

#define emberMarkTaskActive
Value:
(taskid)

Calling it indicates that a task has something to do, so it should prevent the CPU from idling until emberMarkTaskIdle is next called on this task.


Definition at line 417 of file /mnt/raid/workspaces/ws.SZ9MaSA5u/overlay/gsdk/protocol/flex/stack/include/event.h