Message Queue Manager. More...

Collaboration diagram for Message Queues:

Data Structures
struct	Message_queue_Control
	The following records define the control block used to manage each message queue. More...
Enumerations
enum	Message_queue_Submit_types { MESSAGE_QUEUE_SEND_REQUEST = 0, MESSAGE_QUEUE_URGENT_REQUEST = 1 }
	The following enumerated type details the modes in which a message may be submitted to a message queue. More...
Functions
void	_Message_queue_Manager_initialization (void)
	Message Queue Manager Initialization.
rtems_status_code	rtems_message_queue_create (rtems_name name, uint32_t count, size_t max_message_size, rtems_attribute attribute_set, rtems_id *id)
	RTEMS Create Message Queue.
rtems_status_code	rtems_message_queue_ident (rtems_name name, uint32_t node, rtems_id *id)
	RTEMS Message Queue Name to Id.
rtems_status_code	rtems_message_queue_delete (rtems_id id)
	RTEMS Delete Message Queue.
rtems_status_code	rtems_message_queue_send (rtems_id id, const void *buffer, size_t size)
	rtems_message_queue_send
rtems_status_code	rtems_message_queue_urgent (rtems_id id, const void *buffer, size_t size)
	RTEMS Urgent Message Queue.
rtems_status_code	rtems_message_queue_broadcast (rtems_id id, const void buffer, size_t size, uint32_t count)
	RTEMS Broadcast Message Queue.
rtems_status_code	rtems_message_queue_receive (rtems_id id, void buffer, size_t size, rtems_option option_set, rtems_interval timeout)
	RTEMS Message Queue Receive.
rtems_status_code	rtems_message_queue_flush (rtems_id id, uint32_t *count)
	rtems_message_queue_flush
rtems_status_code	rtems_message_queue_get_number_pending (rtems_id id, uint32_t *count)
	RTEMS Message Queue Get Number Pending.
rtems_status_code	_Message_queue_Submit (rtems_id id, const void *buffer, size_t size, Message_queue_Submit_types submit_type)
	Message_queue_Submit.
Message_queue_Control *	_Message_queue_Allocate (void)
	Message Queue Allocate.
rtems_status_code	_Message_queue_Translate_core_message_queue_return_code (uint32_t the_message_queue_status)
	Message queue Translate Core Message Queue Return Code.
void	_Message_queue_Core_message_queue_mp_support (Thread_Control *the_thread, rtems_id id)
	Message_queue_Core_message_queue_mp_support.
RTEMS_INLINE_ROUTINE bool	_Message_queue_Is_null (Message_queue_Control *the_message_queue)
	Check whether message queue is null.
RTEMS_INLINE_ROUTINE void	_Message_queue_Free (Message_queue_Control *the_message_queue)
	Deallocates a message queue control block into the inactive chain of free message queue control blocks.
RTEMS_INLINE_ROUTINE Message_queue_Control *	_Message_queue_Get (Objects_Id id, Objects_Locations *location)
	Maps message queue IDs to message queue control blocks.
Variables
RTEMS_MESSAGE_EXTERN Objects_Information	_Message_queue_Information
	The following defines the information control block used to manage this class of objects.

Detailed Description

Message Queue Manager.

This encapsulates functionality which XXX.

This include file contains all the constants and structures associated with the Message Queue Manager. This manager provides a mechanism for communication and synchronization between tasks using messages.

Directives provided are:

create a queue
get ID of a queue
delete a queue
put a message at the rear of a queue
put a message at the front of a queue
broadcast N messages to a queue
receive message from a queue
flush all messages on a queue

Enumeration Type Documentation

enum Message_queue_Submit_types

The following enumerated type details the modes in which a message may be submitted to a message queue.

The message may be posted in a send or urgent fashion.

Enumerator:

MESSAGE_QUEUE_SEND_REQUEST	This value indicates the user wants to send the message using the normal message insertion protocol (FIFO or priority).
MESSAGE_QUEUE_URGENT_REQUEST	This value indicates the user considers the message to be urgent and wants it inserted at the head of the pending message queue.

Function Documentation

Message_queue_Control* _Message_queue_Allocate ( void )

Message Queue Allocate.

This function allocates a message queue control block from the inactive chain of free message queue control blocks.

Return values:

the_message_queue filled in if successful, NULL otherwise

void _Message_queue_Core_message_queue_mp_support	(	Thread_Control *	the_thread,
		rtems_id	id
	)

Message_queue_Core_message_queue_mp_support.

Input parameters: the_thread - the remote thread the message was submitted to id - id of the message queue

Output parameters: NONE

RTEMS_INLINE_ROUTINE void _Message_queue_Free ( Message_queue_Control * the_message_queue )

Deallocates a message queue control block into the inactive chain of free message queue control blocks.

This routine deallocates a message queue control block into the inactive chain of free message queue control blocks.

References _Objects_Free(), _Message_queue_Information, and Message_queue_Control::Object.

RTEMS_INLINE_ROUTINE Message_queue_Control* _Message_queue_Get	(	Objects_Id	id,
		Objects_Locations *	location
	)

Maps message queue IDs to message queue control blocks.

This function maps message queue IDs to message queue control blocks. If ID corresponds to a local message queue, then it returns the_message_queue control pointer which maps to ID and location is set to OBJECTS_LOCAL. If the message queue ID is global and resides on a remote node, then location is set to OBJECTS_REMOTE, and the_message_queue is undefined. Otherwise, location is set to OBJECTS_ERROR and the_message_queue is undefined.

References _Objects_Get(), and _Message_queue_Information.

RTEMS_INLINE_ROUTINE bool _Message_queue_Is_null ( Message_queue_Control * the_message_queue )

Check whether message queue is null.

This function places the_message at the rear of the outstanding messages on the_message_queue.

void _Message_queue_Manager_initialization ( void )

Message Queue Manager Initialization.

This routine performs the initialization necessary for this manager.

rtems_status_code _Message_queue_Submit	(	rtems_id	id,
		const void *	buffer,
		size_t	size,
		Message_queue_Submit_types	submit_type
	)

Message_queue_Submit.

This routine implements the directives rtems_message_queue_send and rtems_message_queue_urgent. It processes a message that is to be submitted to the designated message queue. The message will either be processed as a send send message which it will be inserted at the rear of the queue or it will be processed as an urgent message which will be inserted at the front of the queue.

rtems_status_code _Message_queue_Translate_core_message_queue_return_code ( uint32_t the_message_queue_status )

Message queue Translate Core Message Queue Return Code.

This function returns a RTEMS status code based on the_message_queue_status.

Parameters:

[in] the_message_queue_status is the status code to translate

Return values:

translated RTEMS status code

rtems_status_code rtems_message_queue_broadcast	(	rtems_id	id,
		const void *	buffer,
		size_t	size,
		uint32_t *	count
	)

RTEMS Broadcast Message Queue.

This routine implements the rtems_message_queue_broadcast directive. This directive sends the message buffer to all of the tasks blocked waiting for a message on the message queue indicated by ID. If no tasks are waiting, then the message buffer will not be queued.

Parameters:

[in]	id	is the pointer to message queue
[in]	buffer	is the pointer to message buffer
[in]	size	is the size of message to broadcast
[in]	count	pointer to area to store number of threads made ready

Return values:

RTEMS_SUCCESSFUL if successful or error code if unsuccessful and *count filled in with number of threads made ready

rtems_status_code rtems_message_queue_create	(	rtems_name	name,
		uint32_t	count,
		size_t	max_message_size,
		rtems_attribute	attribute_set,
		rtems_id *	id
	)

RTEMS Create Message Queue.

This routine implements the rtems_message_queue_create directive. The message queue will have the name. If the attribute_set indicates that the message queue is to be limited in the number of messages that can be outstanding, then count indicates the maximum number of messages that will be held. It returns the id of the created message queue in id.

Parameters:

[in]	name	is the user defined queue name
[in]	count	is the maximum message and reserved buffer count
[in]	max_message_size	is the maximum size of each message
[in]	attribute_set	is the process method
[in]	id	is the pointer to queue

Return values:

This	method returns RTEMS_SUCCESSFUL if there was not an error. Otherwise, a status code is returned indicating the source of the error. If successful, the id will be filled in with the queue id.

rtems_status_code rtems_message_queue_delete ( rtems_id id )

RTEMS Delete Message Queue.

This routine implements the rtems_message_queue_delete directive. The message queue indicated by ID is deleted.

Parameters:

[in] id is the queue id

Return values:

RTEMS_SUCCESSFUL if successful or error code if unsuccessful

rtems_status_code rtems_message_queue_flush	(	rtems_id	id,
		uint32_t *	count
	)

rtems_message_queue_flush

This routine implements the rtems_message_queue_flush directive. This directive takes all outstanding messages for the message queue indicated by ID and returns them to the inactive message chain. The number of messages flushed is returned in COUNT.

Message Queue Manager

rtems_status_code rtems_message_queue_get_number_pending	(	rtems_id	id,
		uint32_t *	count
	)

RTEMS Message Queue Get Number Pending.

Message Queue Manager

This routine implements the rtems_message_queue_get_number_pending directive. This directive returns the number of pending messages for the message queue indicated by ID chain. The number of messages pending is returned in COUNT.

rtems_status_code rtems_message_queue_ident	(	rtems_name	name,
		uint32_t	node,
		rtems_id *	id
	)

RTEMS Message Queue Name to Id.

This routine implements the rtems_message_queue_ident directive. This directive returns the message queue ID associated with NAME. If more than one message queue is named name, then the message queue to which the ID belongs is arbitrary. node indicates the extent of the search for the ID of the message queue named name. The search can be limited to a particular node or allowed to encompass all nodes.

Parameters:

[in]	name	is the user defined message queue name
[in]	node	is the node(s) to be searched
[in]	id	is the pointer to message queue id

Return values:

RTEMS_SUCCESSFUL if successful or error code if unsuccessful and *id filled with the message queue id

rtems_status_code rtems_message_queue_receive	(	rtems_id	id,
		void *	buffer,
		size_t *	size,
		rtems_option	option_set,
		rtems_interval	timeout
	)

RTEMS Message Queue Receive.

This routine implements the rtems_message_queue_receive directive. This directive is invoked when the calling task wishes to receive a message from the message queue indicated by ID. The received message is to be placed in buffer. If no messages are outstanding and the option_set indicates that the task is willing to block, then the task will be blocked until a message arrives or until, optionally, timeout clock ticks have passed.

Parameters:

[in]	id	is the queue id
[in]	buffer	is the pointer to message buffer
[in]	size	is the size of message receive
[in]	option_set	is the options on receive
[in]	timeout	is the number of ticks to wait

Return values:

This	method returns RTEMS_SUCCESSFUL if there was not an error. Otherwise, a status code is returned indicating the source of the error.

rtems_status_code rtems_message_queue_send	(	rtems_id	id,
		const void *	buffer,
		size_t	size
	)

rtems_message_queue_send

Message Queue Manager - rtems_message_queue_send

This routine implements the rtems_message_queue_send directive. This directive sends the message buffer to the message queue indicated by ID. If one or more tasks is blocked waiting to receive a message from this message queue, then one will receive the message. The task selected to receive the message is based on the task queue discipline algorithm in use by this particular message queue. If no tasks are waiting, then the message buffer will be placed at the REAR of the chain of pending messages for this message queue.

rtems_status_code rtems_message_queue_urgent	(	rtems_id	id,
		const void *	buffer,
		size_t	size
	)

RTEMS Urgent Message Queue.

This routine implements the rtems_message_queue_urgent directive. This directive has the same behavior as rtems_message_queue_send except that if no tasks are waiting, the message buffer will be placed at the FRONT of the chain of pending messages rather than at the REAR.

Parameters:

[in]	id	is the pointer to message queue
[in]	buffer	is the pointer to message buffer
[in]	size	is the size of message to send urgently

Return values:

RTEMS_SUCCESSFUL if successful or error code if unsuccessful

Data Structures

Enumerations

Functions

Variables

Detailed Description

Enumeration Type Documentation

Function Documentation