blob: 4e15ab5bc0b37634885573d9883925e96a61de73 (
plain) (
tree)
|
|
/*
* 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.
*
* $Id$
*/
#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_Submit
*
* This routine implements the send and urgent message functions. It
* processes a message that is to be submitted to the designated
* message queue. The message will either be processed as a
* 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.
*
* Input parameters:
* the_message_queue - message is submitted to this message queue
* buffer - pointer to message buffer
* size - size in bytes of message to send
* id - id of message queue
* api_message_queue_mp_support - api specific mp support callout
* submit_type - send or urgent message
*
* Output parameters:
* CORE_MESSAGE_QUEUE_SUCCESSFUL - if successful
* error code - if unsuccessful
*/
CORE_message_queue_Status _CORE_message_queue_Submit(
CORE_message_queue_Control *the_message_queue,
void *buffer,
unsigned32 size,
Objects_Id id,
CORE_message_queue_API_mp_support_callout api_message_queue_mp_support,
CORE_message_queue_Submit_types submit_type
)
{
CORE_message_queue_Buffer_control *the_message;
Thread_Control *the_thread;
if ( size > the_message_queue->maximum_message_size )
return CORE_MESSAGE_QUEUE_STATUS_INVALID_SIZE;
/*
* Is there a thread currently waiting on this message queue?
*/
the_thread = _Thread_queue_Dequeue( &the_message_queue->Wait_queue );
if ( the_thread ) {
_CORE_message_queue_Copy_buffer(
buffer,
the_thread->Wait.return_argument,
size
);
*(unsigned32 *)the_thread->Wait.return_argument_1 = size;
the_thread->Wait.count = submit_type;
#if defined(RTEMS_MULTIPROCESSING)
if ( !_Objects_Is_local_id( the_thread->Object.id ) )
(*api_message_queue_mp_support) ( the_thread, id );
#endif
return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL;
}
/*
* No one waiting on this one currently.
* Allocate a message buffer and store it away
*/
if ( the_message_queue->number_of_pending_messages ==
the_message_queue->maximum_pending_messages ) {
return CORE_MESSAGE_QUEUE_STATUS_TOO_MANY;
}
the_message = _CORE_message_queue_Allocate_message_buffer(the_message_queue);
if ( the_message == 0 )
return CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED;
_CORE_message_queue_Copy_buffer( buffer, the_message->Contents.buffer, size );
the_message->Contents.size = size;
the_message->priority = submit_type;
the_message_queue->number_of_pending_messages += 1;
switch ( submit_type ) {
case CORE_MESSAGE_QUEUE_SEND_REQUEST:
_CORE_message_queue_Append( the_message_queue, the_message );
break;
case CORE_MESSAGE_QUEUE_URGENT_REQUEST:
_CORE_message_queue_Prepend( the_message_queue, the_message );
break;
default:
/* XXX interrupt critical section needs to be addressed */
{
CORE_message_queue_Buffer_control *this_message;
Chain_Node *the_node;
the_message->priority = submit_type;
for ( the_node = the_message_queue->Pending_messages.first ;
!_Chain_Is_tail( &the_message_queue->Pending_messages, the_node ) ;
the_node = the_node->next ) {
this_message = (CORE_message_queue_Buffer_control *) the_node;
if ( this_message->priority >= the_message->priority )
continue;
_Chain_Insert( the_node, &the_message->Node );
break;
}
}
break;
}
/*
* According to POSIX, does this happen before or after the message
* is actually enqueued. It is logical to think afterwards, because
* the message is actually in the queue at this point.
*/
if ( the_message_queue->number_of_pending_messages == 1 &&
the_message_queue->notify_handler )
(*the_message_queue->notify_handler)( the_message_queue->notify_argument );
return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL;
}
|