Barrier Handler

Data Structures
struct	CORE_barrier_Attributes
struct	CORE_barrier_Control
Defines
#define	CORE_BARRIER_STATUS_LAST   CORE_BARRIER_TIMEOUT
	Core Barrier Last Status.
#define	_CORE_barrier_Flush(_the_barrier, _remote_extract_callout, _status)
Typedefs
typedef void(*	CORE_barrier_API_mp_support_callout )(Thread_Control *, Objects_Id)
Enumerations
enum	CORE_barrier_Disciplines { CORE_BARRIER_AUTOMATIC_RELEASE, CORE_BARRIER_MANUAL_RELEASE }
enum	CORE_barrier_Status { CORE_BARRIER_STATUS_SUCCESSFUL, CORE_BARRIER_STATUS_AUTOMATICALLY_RELEASED, CORE_BARRIER_WAS_DELETED, CORE_BARRIER_TIMEOUT }
Functions
void	_CORE_barrier_Initialize (CORE_barrier_Control *the_barrier, CORE_barrier_Attributes *the_barrier_attributes)
void	_CORE_barrier_Wait (CORE_barrier_Control *the_barrier, Objects_Id id, boolean wait, Watchdog_Interval timeout, CORE_barrier_API_mp_support_callout api_barrier_mp_support)
uint32_t	_CORE_barrier_Release (CORE_barrier_Control *the_barrier, Objects_Id id, CORE_barrier_API_mp_support_callout api_barrier_mp_support)
RTEMS_INLINE_ROUTINE boolean	_CORE_barrier_Is_automatic (CORE_barrier_Attributes *the_attribute)
RTEMS_INLINE_ROUTINE uint32_t	_CORE_barrier_Get_number_of_waiting_threads (CORE_barrier_Control *the_barrier)

---

Detailed Description

This handler encapsulates functionality which provides the foundation Barrier services used in all of the APIs supported by RTEMS.

---

Define Documentation

#define _CORE_barrier_Flush	(	_the_barrier,
		_remote_extract_callout,
		_status		)

Value:

_Thread_queue_Flush( \
    &((_the_barrier)->Wait_queue), \
    (_remote_extract_callout), \
    (_status) \
  )

This routine assists in the deletion of a barrier by flushing the associated wait queue.

Parameters:

[in]	_the_barrier	is the barrier to flush
[in]	_remote_extract_callout	is the routine to invoke if the thread unblocked is remote
[in]	_status	is the status to be returned to the unblocked thread

#define CORE_BARRIER_STATUS_LAST   CORE_BARRIER_TIMEOUT

Core Barrier Last Status.

This is the last status value.

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Typedef Documentation

typedef void( * CORE_barrier_API_mp_support_callout)(Thread_Control *, Objects_Id)

The following type defines the callout which the API provides to support global/multiprocessor operations on barriers.

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Enumeration Type Documentation

enum CORE_barrier_Disciplines

Flavors of barriers.

Enumerator:

CORE_BARRIER_AUTOMATIC_RELEASE	This specifies that the barrier will automatically release when the user specified number of threads have arrived at the barrier.
CORE_BARRIER_MANUAL_RELEASE	This specifies that the user will have to manually release the barrier in order to release the waiting threads.

enum CORE_barrier_Status

Core Barrier handler return statuses.

Enumerator:

CORE_BARRIER_STATUS_SUCCESSFUL	This status indicates that the operation completed successfully.
CORE_BARRIER_STATUS_AUTOMATICALLY_RELEASED	This status indicates that the barrier is configured for automatic release and the caller tripped the automatic release. The caller thus did not block.
CORE_BARRIER_WAS_DELETED	This status indicates that the thread was blocked waiting for an operation to complete and the barrier was deleted.
CORE_BARRIER_TIMEOUT	This status indicates that the calling task was willing to block but the operation was unable to complete within the time allotted because the resource never became available.

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Function Documentation

RTEMS_INLINE_ROUTINE uint32_t _CORE_barrier_Get_number_of_waiting_threads

(

CORE_barrier_Control *

the_barrier

)

This routine returns the number of threads currently waiting at the barrier.

Parameters:

[in]

the_barrier

is the barrier to obtain the number of blocked threads for

Returns:

the current count of this barrier

References CORE_barrier_Control::number_of_waiting_threads.

void _CORE_barrier_Initialize	(	CORE_barrier_Control *	the_barrier,
		CORE_barrier_Attributes *	the_barrier_attributes
	)

This routine initializes the barrier based on the parameters passed.

Parameters:

[in]	the_barrier	is the barrier to initialize
[in]	the_barrier_attributes	define the behavior of this instance

RTEMS_INLINE_ROUTINE boolean _CORE_barrier_Is_automatic

(

CORE_barrier_Attributes *

the_attribute

)

This function returns TRUE if the automatic release attribute is enabled in the attribute_set and FALSE otherwise.

Parameters:

[in]

the_attribute

is the attribute set to test

Returns:

TRUE if the priority attribute is enabled

References CORE_BARRIER_AUTOMATIC_RELEASE, and CORE_barrier_Attributes::discipline.

uint32_t _CORE_barrier_Release	(	CORE_barrier_Control *	the_barrier,
		Objects_Id	id,
		CORE_barrier_API_mp_support_callout	api_barrier_mp_support
	)

This routine manually releases the barrier. All of the threads waiting for the barrier will be readied.

Parameters:

[in]	the_barrier	is the barrier to surrender
[in]	id	is the id of the object for a remote unblock
[in]	api_barrier_mp_support	is the routine to invoke if the thread unblocked is remote

Returns:

the number of unblocked threads

void _CORE_barrier_Wait	(	CORE_barrier_Control *	the_barrier,
		Objects_Id	id,
		boolean	wait,
		Watchdog_Interval	timeout,
		CORE_barrier_API_mp_support_callout	api_barrier_mp_support
	)

This routine wait for the barrier to be released. If the barrier is set to automatic and this is the appropriate thread, then it returns immediately. Otherwise, the calling thread is blocked until the barrier is released.

Parameters:

[in]	the_barrier	is the barrier to wait for
[in]	id	is the id of the object being waited upon
[in]	wait	is TRUE if the calling thread is willing to wait
[in]	timeout	is the number of ticks the calling thread is willing to wait if wait is TRUE.
[in]	api_barrier_mp_support	is the routine to invoke if the thread unblocked is remote

Note:

Status is returned via the thread control block.