/**
* @file rtems/rtems/message.h
*
* @defgroup ClassicMessageQueue Message Queues
*
* @ingroup ClassicRTEMS
* @brief Message Queue Manager
*
* 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
*/
/* COPYRIGHT (c) 1989-2013.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#ifndef _RTEMS_RTEMS_MESSAGE_H
#define _RTEMS_RTEMS_MESSAGE_H
#include <rtems/rtems/types.h>
#include <rtems/rtems/status.h>
#include <rtems/rtems/options.h>
#include <rtems/rtems/attr.h>
#include <rtems/score/object.h>
#include <rtems/score/coremsg.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @ingroup ClassicMessageQueueImpl
*
* The following records define the control block used to manage
* each message queue.
*/
typedef struct {
/** This field is the inherited object characteristics. */
Objects_Control Object;
/** This field is the instance of the SuperCore Message Queue. */
CORE_message_queue_Control message_queue;
/** This field is the attribute set as defined by the API. */
rtems_attribute attribute_set;
} Message_queue_Control;
/**
* @defgroup ClassicMessageQueue Message Queues
*
* @ingroup ClassicRTEMS
*
* This encapsulates functionality related to the Classic API Message Queue
* Manager.
*/
/**@{*/
/**
* @brief RTEMS Create Message Queue
*
* This routine implements the rtems_message_queue_create directive. The
* message queue will have the @a name. If the @a attribute_set indicates
* that the message queue is to be limited in the number of messages
* that can be outstanding, then @a count indicates the maximum number of
* messages that will be held. It returns the id of the created
* message queue in @a id.
*
* @param[in] name is the user defined queue name
* @param[in] count is the maximum message and reserved buffer count
* @param[in] max_message_size is the maximum size of each message
* @param[in] attribute_set is the process method
* @param[in] id is the pointer to queue
*
* @retval 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 @a id will
* be filled in with the queue id.
*/
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
);
/**
* @brief 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.
*
* @param[in] name is the user defined message queue name
* @param[in] node is the node(s) to be searched
* @param[in] id is the pointer to message queue id
*
* @retval RTEMS_SUCCESSFUL if successful or error code if unsuccessful and
* *id filled with the message queue id
*/
rtems_status_code rtems_message_queue_ident(
rtems_name name,
uint32_t node,
rtems_id *id
);
/**
* @brief RTEMS Delete Message Queue
*
* This routine implements the rtems_message_queue_delete directive. The
* message queue indicated by ID is deleted.
*
* @param[in] id is the queue id
*
* @retval RTEMS_SUCCESSFUL if successful or error code if unsuccessful
*/
rtems_status_code rtems_message_queue_delete(
rtems_id id
);
/**
* @brief 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_send(
rtems_id id,
const void *buffer,
size_t size
);
/**
* @brief 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.
*
* @param[in] id is the pointer to message queue
* @param[in] buffer is the pointer to message buffer
* @param[in] size is the size of message to send urgently
*
* @retval RTEMS_SUCCESSFUL if successful or error code if unsuccessful
*/
rtems_status_code rtems_message_queue_urgent(
rtems_id id,
const void *buffer,
size_t size
);
/**
* @brief 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.
*
* @param[in] id is the pointer to message queue
* @param[in] buffer is the pointer to message buffer
* @param[in] size is the size of message to broadcast
* @param[in] count pointer to area to store number of threads made ready
*
* @retval 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_broadcast(
rtems_id id,
const void *buffer,
size_t size,
uint32_t *count
);
/**
* @brief 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.
*
* @param[in] id is the queue id
* @param[in] buffer is the pointer to message buffer
* @param[in] size is the size of message receive
* @param[in] option_set is the options on receive
* @param[in] timeout is the number of ticks to wait
*
* @retval 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_receive(
rtems_id id,
void *buffer,
size_t *size,
rtems_option option_set,
rtems_interval timeout
);
/**
* @brief 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_flush(
rtems_id id,
uint32_t *count
);
/**
* @brief 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_get_number_pending(
rtems_id id,
uint32_t *count
);
/**@}*/
#ifdef __cplusplus
}
#endif
#endif
/* end of include file */
