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/*

 *  CORE Message Queue Handler

 *

 *  DESCRIPTION:

 *

 *  This package is the implementation of the CORE Message Queue Handler.

 *  This core object provides task synchronization and communication functions

 *  via messages passed to queue objects.

 *

 *  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.

 *

 *  coremsg.c,v 1.14 2002/07/01 22:30:12 joel Exp

 */

#include <rtems/system.h>

#include <rtems/score/chain.h>

#include <rtems/score/isr.h>

#include <rtems/score/object.h>

#include <rtems/score/coremsg.h>

#include <rtems/score/states.h>

#include <rtems/score/thread.h>

#include <rtems/score/wkspace.h>

#if defined(RTEMS_MULTIPROCESSING)

#include <rtems/score/mpci.h>

#endif

/*PAGE

 *

 *  _CORE_message_queue_Initialize

 *

 *  This routine initializes a newly created message queue based on the

 *  specified data.

 *

 *  Input parameters:

 *    the_message_queue            - the message queue to initialize

 *    the_class                    - the API specific object class

 *    the_message_queue_attributes - the message queue's attributes

 *    maximum_pending_messages     - maximum message and reserved buffer count

 *    maximum_message_size         - maximum size of each message

 *

 *  Output parameters:

 *    TRUE   - if the message queue is initialized

 *    FALSE  - if the message queue is NOT initialized

 */

boolean _CORE_message_queue_Initialize(

  CORE_message_queue_Control    *the_message_queue,

  CORE_message_queue_Attributes *the_message_queue_attributes,

  unsigned32                     maximum_pending_messages,

  unsigned32                     maximum_message_size

)

{

  unsigned32 message_buffering_required;

  unsigned32 allocated_message_size;

  the_message_queue->maximum_pending_messages   = maximum_pending_messages;

  the_message_queue->number_of_pending_messages = 0;

  the_message_queue->maximum_message_size       = maximum_message_size;

  _CORE_message_queue_Set_notify( the_message_queue, NULL, NULL );

  /*

   * round size up to multiple of a ptr for chain init

   */

  allocated_message_size = maximum_message_size;

  if (allocated_message_size & (sizeof(unsigned32) - 1)) {

      allocated_message_size += sizeof(unsigned32);

      allocated_message_size &= ~(sizeof(unsigned32) - 1);

  }

  message_buffering_required = maximum_pending_messages *

       (allocated_message_size + sizeof(CORE_message_queue_Buffer_control));

  the_message_queue->message_buffers = (CORE_message_queue_Buffer *)

     _Workspace_Allocate( message_buffering_required );

  if (the_message_queue->message_buffers == 0)

    return FALSE;

  _Chain_Initialize (

    &the_message_queue->Inactive_messages,

    the_message_queue->message_buffers,

    maximum_pending_messages,

    allocated_message_size + sizeof( CORE_message_queue_Buffer_control )

  );

  _Chain_Initialize_empty( &the_message_queue->Pending_messages );

  _Thread_queue_Initialize(

    &the_message_queue->Wait_queue,

    _CORE_message_queue_Is_priority( the_message_queue_attributes ) ?

       THREAD_QUEUE_DISCIPLINE_PRIORITY : THREAD_QUEUE_DISCIPLINE_FIFO,

    STATES_WAITING_FOR_MESSAGE,

    CORE_MESSAGE_QUEUE_STATUS_TIMEOUT

  );

  return TRUE;

}