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/**
* @file
*
* @brief Size a Message from the Message Queue
* @ingroup ScoreMessageQueue
*/
/*
* COPYRIGHT (c) 1989-2007.
* 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.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/system.h>
#include <rtems/score/chain.h>
#include <rtems/score/isr.h>
#include <rtems/score/object.h>
#include <rtems/score/coremsgimpl.h>
#include <rtems/score/thread.h>
#include <rtems/score/wkspace.h>
void _CORE_message_queue_Seize(
CORE_message_queue_Control *the_message_queue,
Thread_Control *executing,
Objects_Id id,
void *buffer,
size_t *size_p,
bool wait,
Watchdog_Interval timeout
)
{
ISR_Level level;
CORE_message_queue_Buffer_control *the_message;
executing->Wait.return_code = CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL;
_ISR_Disable( level );
the_message = _CORE_message_queue_Get_pending_message( the_message_queue );
if ( the_message != NULL ) {
the_message_queue->number_of_pending_messages -= 1;
_ISR_Enable( level );
*size_p = the_message->Contents.size;
executing->Wait.count =
_CORE_message_queue_Get_message_priority( the_message );
_CORE_message_queue_Copy_buffer(
the_message->Contents.buffer,
buffer,
*size_p
);
#if !defined(RTEMS_SCORE_COREMSG_ENABLE_BLOCKING_SEND)
/*
* There is not an API with blocking sends enabled.
* So return immediately.
*/
_CORE_message_queue_Free_message_buffer(the_message_queue, the_message);
return;
#else
{
Thread_Control *the_thread;
/*
* There could be a thread waiting to send a message. If there
* is not, then we can go ahead and free the buffer.
*
* NOTE: If we note that the queue was not full before this receive,
* then we can avoid this dequeue.
*/
the_thread = _Thread_queue_Dequeue( &the_message_queue->Wait_queue );
if ( !the_thread ) {
_CORE_message_queue_Free_message_buffer(
the_message_queue,
the_message
);
return;
}
/*
* There was a thread waiting to send a message. This code
* puts the messages in the message queue on behalf of the
* waiting task.
*/
_CORE_message_queue_Set_message_priority(
the_message,
the_thread->Wait.count
);
the_message->Contents.size = (size_t) the_thread->Wait.option;
_CORE_message_queue_Copy_buffer(
the_thread->Wait.return_argument_second.immutable_object,
the_message->Contents.buffer,
the_message->Contents.size
);
_CORE_message_queue_Insert_message(
the_message_queue,
the_message,
_CORE_message_queue_Get_message_priority( the_message )
);
return;
}
#endif
}
if ( !wait ) {
_ISR_Enable( level );
executing->Wait.return_code = CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED_NOWAIT;
return;
}
_Thread_queue_Enter_critical_section( &the_message_queue->Wait_queue );
executing->Wait.queue = &the_message_queue->Wait_queue;
executing->Wait.id = id;
executing->Wait.return_argument_second.mutable_object = buffer;
executing->Wait.return_argument = size_p;
/* Wait.count will be filled in with the message priority */
_ISR_Enable( level );
_Thread_queue_Enqueue( &the_message_queue->Wait_queue, timeout );
}
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