coremsgimpl.h

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/*
 *  COPYRIGHT (c) 1989-2009.
 *  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.org/license/LICENSE.
 */

#ifndef _RTEMS_SCORE_COREMSGIMPL_H
#define _RTEMS_SCORE_COREMSGIMPL_H

#include <rtems/score/coremsg.h>
#include <rtems/score/status.h>
#include <rtems/score/chainimpl.h>
#include <rtems/score/threaddispatch.h>
#include <rtems/score/threadqimpl.h>

#include <limits.h>
#include <string.h>

#ifdef __cplusplus
extern "C" {
#endif

#define  CORE_MESSAGE_QUEUE_SEND_REQUEST   INT_MAX

#define  CORE_MESSAGE_QUEUE_URGENT_REQUEST INT_MIN

typedef int CORE_message_queue_Submit_types;

typedef void *( *CORE_message_queue_Allocate_buffers )(
  CORE_message_queue_Control *the_message_queue,
  size_t                      size,
  const void                 *arg
);

void *_CORE_message_queue_Workspace_allocate(
  CORE_message_queue_Control *the_message_queue,
  size_t                      size,
  const void                 *arg
);

Status_Control _CORE_message_queue_Initialize(
  CORE_message_queue_Control          *the_message_queue,
  CORE_message_queue_Disciplines       discipline,
  uint32_t                             maximum_pending_messages,
  size_t                               maximum_message_size,
  CORE_message_queue_Allocate_buffers  allocate_buffers,
  const void                          *arg
);

void _CORE_message_queue_Close(
  CORE_message_queue_Control *the_message_queue,
  Thread_queue_Context       *queue_context
);

uint32_t   _CORE_message_queue_Flush(
  CORE_message_queue_Control *the_message_queue,
  Thread_queue_Context       *queue_context
);

#if defined(FUNCTIONALITY_NOT_CURRENTLY_USED_BY_ANY_API)

  void _CORE_message_queue_Flush_waiting_threads(
    CORE_message_queue_Control *the_message_queue
  );
#endif

Status_Control _CORE_message_queue_Broadcast(
  CORE_message_queue_Control *the_message_queue,
  const void                 *buffer,
  size_t                      size,
  uint32_t                   *count,
  Thread_queue_Context       *queue_context
);

Status_Control _CORE_message_queue_Submit(
  CORE_message_queue_Control       *the_message_queue,
  Thread_Control                   *executing,
  const void                       *buffer,
  size_t                            size,
  CORE_message_queue_Submit_types   submit_type,
  bool                              wait,
  Thread_queue_Context             *queue_context
);

Status_Control _CORE_message_queue_Seize(
  CORE_message_queue_Control *the_message_queue,
  Thread_Control             *executing,
  void                       *buffer,
  size_t                     *size_p,
  bool                        wait,
  Thread_queue_Context       *queue_context
);

void _CORE_message_queue_Insert_message(
  CORE_message_queue_Control        *the_message_queue,
  CORE_message_queue_Buffer         *the_message,
  const void                        *content_source,
  size_t                             content_size,
  CORE_message_queue_Submit_types    submit_type
);

RTEMS_INLINE_ROUTINE Status_Control _CORE_message_queue_Send(
  CORE_message_queue_Control       *the_message_queue,
  const void                       *buffer,
  size_t                            size,
  bool                              wait,
  Thread_queue_Context             *queue_context
)
{
  return _CORE_message_queue_Submit(
    the_message_queue,
    _Thread_Executing,
    buffer,
    size,
    CORE_MESSAGE_QUEUE_SEND_REQUEST,
    wait,
    queue_context
  );
}

RTEMS_INLINE_ROUTINE Status_Control _CORE_message_queue_Urgent(
  CORE_message_queue_Control       *the_message_queue,
  const void                       *buffer,
  size_t                            size,
  bool                              wait,
  Thread_queue_Context             *queue_context
)
{
  return _CORE_message_queue_Submit(
    the_message_queue,
    _Thread_Executing,
    buffer,
    size,
    CORE_MESSAGE_QUEUE_URGENT_REQUEST,
    wait,
    queue_context
  );
}

RTEMS_INLINE_ROUTINE void _CORE_message_queue_Acquire(
  CORE_message_queue_Control *the_message_queue,
  Thread_queue_Context       *queue_context
)
{
  _Thread_queue_Acquire( &the_message_queue->Wait_queue, queue_context );
}

RTEMS_INLINE_ROUTINE void _CORE_message_queue_Acquire_critical(
  CORE_message_queue_Control *the_message_queue,
  Thread_queue_Context       *queue_context
)
{
  _Thread_queue_Acquire_critical( &the_message_queue->Wait_queue, queue_context );
}

RTEMS_INLINE_ROUTINE void _CORE_message_queue_Release(
  CORE_message_queue_Control *the_message_queue,
  Thread_queue_Context       *queue_context
)
{
  _Thread_queue_Release( &the_message_queue->Wait_queue, queue_context );
}

RTEMS_INLINE_ROUTINE void _CORE_message_queue_Copy_buffer (
  const void *source,
  void       *destination,
  size_t      size
)
{
  memcpy(destination, source, size);
}

RTEMS_INLINE_ROUTINE CORE_message_queue_Buffer *
_CORE_message_queue_Allocate_message_buffer (
    CORE_message_queue_Control *the_message_queue
)
{
   return (CORE_message_queue_Buffer *)
     _Chain_Get_unprotected( &the_message_queue->Inactive_messages );
}

RTEMS_INLINE_ROUTINE void _CORE_message_queue_Free_message_buffer (
  CORE_message_queue_Control *the_message_queue,
  CORE_message_queue_Buffer  *the_message
)
{
  _Chain_Append_unprotected( &the_message_queue->Inactive_messages, &the_message->Node );
}

RTEMS_INLINE_ROUTINE int _CORE_message_queue_Get_message_priority (
  const CORE_message_queue_Buffer *the_message
)
{
  #if defined(RTEMS_SCORE_COREMSG_ENABLE_MESSAGE_PRIORITY)
    return the_message->priority;
  #else
    return 0;
  #endif
}

RTEMS_INLINE_ROUTINE
  CORE_message_queue_Buffer *_CORE_message_queue_Get_pending_message (
  CORE_message_queue_Control *the_message_queue
)
{
  return (CORE_message_queue_Buffer *)
    _Chain_Get_unprotected( &the_message_queue->Pending_messages );
}

#if defined(RTEMS_SCORE_COREMSG_ENABLE_NOTIFICATION)

  RTEMS_INLINE_ROUTINE bool _CORE_message_queue_Is_notify_enabled (
    CORE_message_queue_Control *the_message_queue
  )
  {
    return (the_message_queue->notify_handler != NULL);
  }
#endif

#if defined(RTEMS_SCORE_COREMSG_ENABLE_NOTIFICATION)
  RTEMS_INLINE_ROUTINE void _CORE_message_queue_Set_notify (
    CORE_message_queue_Control        *the_message_queue,
    CORE_message_queue_Notify_Handler  the_handler
  )
  {
    the_message_queue->notify_handler = the_handler;
  }
#else
  /* turn it into nothing if not enabled */
  #define _CORE_message_queue_Set_notify( the_message_queue, the_handler ) \
    do { } while ( 0 )
#endif

RTEMS_INLINE_ROUTINE Thread_Control *_CORE_message_queue_Dequeue_receiver(
  CORE_message_queue_Control      *the_message_queue,
  const void                      *buffer,
  size_t                           size,
  CORE_message_queue_Submit_types  submit_type,
  Thread_queue_Context            *queue_context
)
{
  Thread_Control *the_thread;

  /*
   *  If there are pending messages, then there can't be threads
   *  waiting for us to send them a message.
   *
   *  NOTE: This check is critical because threads can block on
   *        send and receive and this ensures that we are broadcasting
   *        the message to threads waiting to receive -- not to send.
   */
  if ( the_message_queue->number_of_pending_messages != 0 ) {
    return NULL;
  }

  /*
   *  There must be no pending messages if there is a thread waiting to
   *  receive a message.
   */
  the_thread = _Thread_queue_First_locked(
    &the_message_queue->Wait_queue,
    the_message_queue->operations
  );
  if ( the_thread == NULL ) {
    return NULL;
  }

   *(size_t *) the_thread->Wait.return_argument = size;
   the_thread->Wait.count = (uint32_t) submit_type;

  _CORE_message_queue_Copy_buffer(
    buffer,
    the_thread->Wait.return_argument_second.mutable_object,
    size
  );

  _Thread_queue_Extract_critical(
    &the_message_queue->Wait_queue.Queue,
    the_message_queue->operations,
    the_thread,
    queue_context
  );

  return the_thread;
}

#ifdef __cplusplus
}
#endif

#endif
/* end of include file */