Notifier Functions

Functions
HAL_NotifierHandle	HAL_InitializeNotifier (int32_t *status)
	Initializes a notifier. More...
HAL_Bool	HAL_SetNotifierThreadPriority (HAL_Bool realTime, int32_t priority, int32_t *status)
	Sets the HAL notifier thread priority. More...
void	HAL_SetNotifierName (HAL_NotifierHandle notifierHandle, const char *name, int32_t *status)
	Sets the name of a notifier. More...
void	HAL_StopNotifier (HAL_NotifierHandle notifierHandle, int32_t *status)
	Stops a notifier from running. More...
void	HAL_CleanNotifier (HAL_NotifierHandle notifierHandle, int32_t *status)
	Cleans a notifier. More...
void	HAL_UpdateNotifierAlarm (HAL_NotifierHandle notifierHandle, uint64_t triggerTime, int32_t *status)
	Updates the trigger time for a notifier. More...
void	HAL_CancelNotifierAlarm (HAL_NotifierHandle notifierHandle, int32_t *status)
	Cancels the next notifier alarm. More...
WPI_NODISCARD uint64_t	HAL_WaitForNotifierAlarm (HAL_NotifierHandle notifierHandle, int32_t *status)
	Waits for the next alarm for the specific notifier. More...

Detailed Description

Function Documentation

HAL_CancelNotifierAlarm()

void HAL_CancelNotifierAlarm	(	HAL_NotifierHandle	notifierHandle,
		int32_t *	status
	)

Cancels the next notifier alarm.

This does not cause HAL_WaitForNotifierAlarm to return.

Parameters

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

HAL_CleanNotifier()

void HAL_CleanNotifier	(	HAL_NotifierHandle	notifierHandle,
		int32_t *	status
	)

Cleans a notifier.

Note this also stops a notifier if it is already running.

Parameters

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

HAL_InitializeNotifier()

HAL_NotifierHandle HAL_InitializeNotifier

(

int32_t *

status

)

Initializes a notifier.

A notifier is an FPGA controller timer that triggers at requested intervals based on the FPGA time. This can be used to make precise control loops.

Parameters

[out]

status

Error status variable. 0 on success.

Returns

the created notifier

HAL_SetNotifierName()

void HAL_SetNotifierName	(	HAL_NotifierHandle	notifierHandle,
		const char *	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 FPGA'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.

HAL_StopNotifier()

void HAL_StopNotifier	(	HAL_NotifierHandle	notifierHandle,
		int32_t *	status
	)

Stops a notifier from running.

This will cause any call into HAL_WaitForNotifierAlarm to return with time = 0.

Parameters

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

HAL_UpdateNotifierAlarm()

void HAL_UpdateNotifierAlarm	(	HAL_NotifierHandle	notifierHandle,
		uint64_t	triggerTime,
		int32_t *	status
	)

Updates the trigger time for a notifier.

Note that this time is an absolute time relative to HAL_GetFPGATime()

Parameters

[in]	notifierHandle	the notifier handle
[in]	triggerTime	the updated trigger time
[out]	status	Error status variable. 0 on success.

HAL_WaitForNotifierAlarm()

WPI_NODISCARD uint64_t HAL_WaitForNotifierAlarm	(	HAL_NotifierHandle	notifierHandle,
		int32_t *	status
	)

Waits for the next alarm for the specific notifier.

This is a blocking call until either the time elapses or HAL_StopNotifier gets called. If the latter occurs, this function will return zero and any loops using this function should exit. Failing to do so can lead to use-after-frees.

Parameters

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

Returns

the FPGA time the notifier returned