Notifier Functions

Functions
HAL_NotifierHandle	HAL_CreateNotifier (int32_t *status)
	Creates a notifier.
HAL_Bool	HAL_SetNotifierThreadPriority (HAL_Bool realTime, int32_t priority, int32_t *status)
	Sets the HAL notifier thread priority.
void	HAL_SetNotifierName (HAL_NotifierHandle notifierHandle, const struct WPI_String *name, int32_t *status)
	Sets the name of a notifier.
void	HAL_DestroyNotifier (HAL_NotifierHandle notifierHandle)
	Destroys a notifier.
void	HAL_SetNotifierAlarm (HAL_NotifierHandle notifierHandle, uint64_t alarmTime, uint64_t intervalTime, HAL_Bool absolute, HAL_Bool ack, int32_t *status)
	Updates the initial and interval alarm times for a notifier.
void	HAL_CancelNotifierAlarm (HAL_NotifierHandle notifierHandle, HAL_Bool ack, int32_t *status)
	Cancels all future notifier alarms for a notifier.
void	HAL_AcknowledgeNotifierAlarm (HAL_NotifierHandle notifierHandle, int32_t *status)
	Indicates the notifier alarm has been serviced.
int32_t	HAL_GetNotifierOverrun (HAL_NotifierHandle notifierHandle, int32_t *status)
	Gets the overrun count for a notifier.

Detailed Description

Function Documentation

HAL_AcknowledgeNotifierAlarm()

void HAL_AcknowledgeNotifierAlarm	(	HAL_NotifierHandle	notifierHandle,
		int32_t *	status )

Indicates the notifier alarm has been serviced.

Makes no change to future alarms.

One of HAL_SetNotifierAlarm (with ack=true), HAL_CancelNotifierAlarm (with ack=true), or this function must be called before waiting for the next alarm.

Parameters

[in]	notifierHandle	the notifier handle
[out]	status	Error status variable. 0 on success.

HAL_CancelNotifierAlarm()

void HAL_CancelNotifierAlarm	(	HAL_NotifierHandle	notifierHandle,
		HAL_Bool	ack,
		int32_t *	status )

Cancels all future notifier alarms for a notifier.

Parameters

[in]	notifierHandle	the notifier handle
[in]	ack	true to acknowledge any prior alarm
[out]	status	Error status variable. 0 on success.

HAL_CreateNotifier()

HAL_NotifierHandle HAL_CreateNotifier

(

int32_t *

status

)

Creates a notifier.

A notifier is an timer that alarms at an initial and (optionally) repeated intervals. This can be used to make precise control loops.

Parameters

[out]

status

Error status variable. 0 on success.

Returns

the created notifier

HAL_DestroyNotifier()

void HAL_DestroyNotifier

(

HAL_NotifierHandle

notifierHandle

)

Destroys a notifier.

Destruction wakes up any waiters.

Parameters

[in]

notifierHandle

the notifier handle

HAL_GetNotifierOverrun()

int32_t HAL_GetNotifierOverrun	(	HAL_NotifierHandle	notifierHandle,
		int32_t *	status )

Gets the overrun count for a notifier.

An overrun occurs when a notifier's alarm is not serviced before the next scheduled alarm time.

Parameters

[in]	notifierHandle	the notifier handle
[out]	status	Error status variable. 0 on success.

Returns

overrun count

HAL_SetNotifierAlarm()

void HAL_SetNotifierAlarm	(	HAL_NotifierHandle	notifierHandle,
		uint64_t	alarmTime,
		uint64_t	intervalTime,
		HAL_Bool	absolute,
		HAL_Bool	ack,
		int32_t *	status )

Updates the initial and interval alarm times for a notifier.

The alarmTime is an absolute time (using the WPI_Now() time base) if absolute is true, or relative to the current time if absolute is false.

If intervalTime is non-zero, the notifier will alarm periodically following alarmTime at the given interval.

If an absolute alarmTime is in the past, the notifier will alarm immediately.

Parameters

[in]	notifierHandle	the notifier handle
[in]	alarmTime	the first alarm time (in microseconds)
[in]	intervalTime	the periodic interval time (in microseconds)
[in]	absolute	true if the alarm time is absolute
[in]	ack	true to acknowledge any prior alarm
[out]	status	Error status variable. 0 on success.

HAL_SetNotifierName()

void HAL_SetNotifierName	(	HAL_NotifierHandle	notifierHandle,
		const struct WPI_String *	name,
		int32_t *	status )

Sets the name of a notifier.

Parameters

[in]	notifierHandle	the notifier handle
[in]	name	name
[out]	status	Error status variable. 0 on success.

HAL_SetNotifierThreadPriority()

HAL_Bool HAL_SetNotifierThreadPriority	(	HAL_Bool	realTime,
		int32_t	priority,
		int32_t *	status )

Sets the HAL notifier thread priority.

The HAL notifier thread is responsible for managing the system's notifier interrupt and waking up user's Notifiers when it's their time to run. Giving the HAL notifier thread real-time priority helps ensure the user's real-time Notifiers, if any, are notified to run in a timely manner.

Parameters

[in]	realTime	Set to true to set a real-time priority, false for standard priority.
[in]	priority	Priority to set the thread to. For real-time, this is 1-99 with 99 being highest. For non-real-time, this is forced to 0. See "man 7 sched" for more details.
[out]	status	Error status variable. 0 on success.

Returns

True on success.