/* 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) 1989-1999.
* 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.OARcorp.com/rtems/license.html.
*
* $Id$
*/
#ifndef __RTEMS_MESSAGE_QUEUE_h
#define __RTEMS_MESSAGE_QUEUE_h
#ifdef __cplusplus
extern "C" {
#endif
#include <rtems/rtems/types.h>
#include <rtems/score/chain.h>
#include <rtems/score/object.h>
#include <rtems/rtems/attr.h>
#include <rtems/score/threadq.h>
#include <rtems/score/coremsg.h>
/*
* 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 {
MESSAGE_QUEUE_SEND_REQUEST = 0,
MESSAGE_QUEUE_URGENT_REQUEST = 1
} Message_queue_Submit_types;
/*
* The following records define the control block used to manage
* each message queue.
*/
typedef struct {
Objects_Control Object;
rtems_attribute attribute_set;
CORE_message_queue_Control message_queue;
} Message_queue_Control;
/*
* The following defines the information control block used to
* manage this class of objects.
*/
RTEMS_EXTERN Objects_Information _Message_queue_Information;
/*
* _Message_queue_Manager_initialization
*
* DESCRIPTION:
*
* This routine performs the initialization necessary for this manager.
*/
void _Message_queue_Manager_initialization(
unsigned32 maximum_message_queues
);
/*
* rtems_message_queue_create
*
* DESCRIPTION:
*
* 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,
unsigned32 count,
unsigned32 max_message_size,
rtems_attribute attribute_set,
Objects_Id *id
);
/*
* rtems_message_queue_ident
*
* DESCRIPTION:
*
* 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,
unsigned32 node,
Objects_Id *id
);
/*
* rtems_message_queue_delete
*
* DESCRIPTION:
*
* This routine implements the rtems_message_queue_delete directive. The
* message queue indicated by ID is deleted.
*/
rtems_status_code rtems_message_queue_delete(
Objects_Id id
);
/*
* rtems_message_queue_send
*
* DESCRIPTION:
*
* 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(
Objects_Id id,
void *buffer,
unsigned32 size
);
/*
* rtems_message_queue_urgent
*
* DESCRIPTION:
*
* 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(
Objects_Id id,
void *buffer,
unsigned32 size
);
/*
* rtems_message_queue_broadcast
*
* DESCRIPTION:
*
* 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(
Objects_Id id,
void *buffer,
unsigned32 size,
unsigned32 *count
);
/*
* rtems_message_queue_receive
*
* DESCRIPTION:
*
* 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(
Objects_Id id,
void *buffer,
unsigned32 *size,
unsigned32 option_set,
rtems_interval timeout
);
/*
* rtems_message_queue_flush
*
* DESCRIPTION:
*
* 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(
Objects_Id id,
unsigned32 *count
);
/*
* rtems_message_queue_get_number_pending
*
* DESCRIPTION:
*
* 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(
Objects_Id id,
unsigned32 *count
);
/*
* _Message_queue_Submit
*
* DESCRIPTION:
*
* 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(
Objects_Id id,
void *buffer,
unsigned32 size,
Message_queue_Submit_types submit_type
);
/*
* _Message_queue_Allocate
*
* DESCRIPTION:
*
* This function allocates a message queue control block from
* the inactive chain of free message queue control blocks.
*/
Message_queue_Control *_Message_queue_Allocate (
unsigned32 count,
unsigned32 max_message_size
);
/*
* _Message_queue_Translate_core_message_queue_return_code
*
* DESCRIPTION:
*
* 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 (
unsigned32 the_message_queue_status
);
/*
*
* _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
*/
#if defined(RTEMS_MULTIPROCESSING)
void _Message_queue_Core_message_queue_mp_support (
Thread_Control *the_thread,
Objects_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 */
