/**
* @file rtems/rtems/message.h
*
* 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) 1989-2008.
* 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.com/license/LICENSE.
*
* $Id$
*/
#ifndef _RTEMS_RTEMS_MESSAGE_H
#define _RTEMS_RTEMS_MESSAGE_H
/**
* This constant is defined to extern most of the time when using
* this header file. However by defining it to nothing, the data
* declared in this header file can be instantiated. This is done
* in a single per manager file.
*/
#ifndef RTEMS_MESSAGE_EXTERN
#define RTEMS_MESSAGE_EXTERN extern
#endif
#ifdef __cplusplus
extern "C" {
#endif
#include <rtems/rtems/types.h>
#include <rtems/rtems/status.h>
#include <rtems/rtems/options.h>
#include <rtems/score/chain.h>
#include <rtems/score/object.h>
#include <rtems/rtems/attr.h>
#include <rtems/score/coremsg.h>
/**
* @defgroup ClassicMessageQueue Message Queues
*
* @ingroup ClassicRTEMS
*
* This encapsulates functionality which XXX
*/
/**@{*/
/**
* 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.
*/
typedef enum {
/**
* This value indicates the user wants to send the message using the
* normal message insertion protocol (FIFO or priority).
*/
MESSAGE_QUEUE_SEND_REQUEST = 0,
/**
* This value indicates the user considers the message to be urgent
* and wants it inserted at the head of the pending message queue.
*/
MESSAGE_QUEUE_URGENT_REQUEST = 1
} Message_queue_Submit_types;
/**
* 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 attribute set as defined by the API. */
rtems_attribute attribute_set;
/** This field is the instance of the SuperCore Message Queue. */
CORE_message_queue_Control message_queue;
} Message_queue_Control;
/**
* The following defines the information control block used to
* manage this class of objects.
*/
RTEMS_MESSAGE_EXTERN Objects_Information _Message_queue_Information;
/**
* @brief Message_queue_Manager_initialization
*
* This routine performs the initialization necessary for this manager.
*/
void _Message_queue_Manager_initialization(void);
/**
* @brief rtems_message_queue_create
*
* This routine implements the rtems_message_queue_create directive. The
* message queue will have the name 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.
*/
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_ident
*
* 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.
*/
rtems_status_code rtems_message_queue_ident(
rtems_name name,
uint32_t node,
rtems_id *id
);
/**
* @brief rtems_message_queue_delete
*
* This routine implements the rtems_message_queue_delete directive. The
* message queue indicated by ID is deleted.
*/
rtems_status_code rtems_message_queue_delete(
rtems_id id
);
/**
* @brief 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_message_queue_urgent
*
* 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.
*/
rtems_status_code rtems_message_queue_urgent(
rtems_id id,
const void *buffer,
size_t size
);
/**
* @brief rtems_message_queue_broadcast
*
* 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.
*/
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.
*/
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.
*/
rtems_status_code rtems_message_queue_flush(
rtems_id id,
uint32_t *count
);
/**
* @brief rtems_message_queue_get_number_pending
*
* 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
);
/**
* @brief 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_Submit(
rtems_id id,
const void *buffer,
size_t size,
Message_queue_Submit_types submit_type
);
/**
* @brief Message_queue_Allocate
*
* This function allocates a message queue control block from
* the inactive chain of free message queue control blocks.
*/
Message_queue_Control *_Message_queue_Allocate (void);
/**
* @brief Message_queue_Translate_core_message_queue_return_code
*
* This function returns a RTEMS status code based on the core message queue
* status code specified.
*/
rtems_status_code _Message_queue_Translate_core_message_queue_return_code (
uint32_t the_message_queue_status
);
#if defined(RTEMS_MULTIPROCESSING)
/**
* @brief 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
*/
void _Message_queue_Core_message_queue_mp_support (
Thread_Control *the_thread,
rtems_id id
);
#endif
#ifndef __RTEMS_APPLICATION__
#include <rtems/rtems/message.inl>
#endif
#if defined(RTEMS_MULTIPROCESSING)
#include <rtems/rtems/msgmp.h>
#endif
#ifdef __cplusplus
}
#endif
/**@}*/
#endif
/* end of include file */
