path: root/cpukit/posix/include/rtems/posix/mqueueimpl.h

/**
 * @file
 *
 * @brief Private Inlined Routines for POSIX Message Queue
 * 
 * This include file contains the static inline implementation of the private 
 * inlined routines for POSIX Message Queue.
 */

/*
 *  COPYRIGHT (c) 1989-2013.
 *  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_POSIX_MQUEUE_INL
#define _RTEMS_POSIX_MQUEUE_INL

#include <rtems/posix/mqueue.h>
#include <rtems/posix/posixapi.h>
#include <rtems/score/coremsgimpl.h>

#ifdef __cplusplus
extern "C" {
#endif

/**
 *  This defines the information control block used to manage
 *  this class of objects.
 */
POSIX_EXTERN Objects_Information  _POSIX_Message_queue_Information;

/**
 *  The is used to manage the set of "file descriptors" associated with
 *  the message queues.
 */
POSIX_EXTERN Objects_Information  _POSIX_Message_queue_Information_fds;

/**
 * @brief Initialize message_queue manager related data structures.
 *
 * This routine performs the initialization necessary for this manager.
 *
 * @note The structure of the routines is identical to that of POSIX
 *       Message_queues to leave the option of having unnamed message
 *       queues at a future date.  They are currently not part of the
 *       POSIX standard but unnamed message_queues are.  This is also
 *       the reason for the apparently unnecessary tracking of
 *       the process_shared attribute.  [In addition to the fact that
 *       it would be trivial to add pshared to the mq_attr structure
 *       and have process private message queues.]
 *
 * @note This code ignores the O_RDONLY/O_WRONLY/O_RDWR flag at open time.
 *
 */
void _POSIX_Message_queue_Manager_initialization(void);

/**
 *  @brief POSIX Message Queue Create Support
 *
 *  This routine performs the creation of a message queue utilizing the
 *  core message queue.
 */
int _POSIX_Message_queue_Create_support(
  const char                    *name,
  size_t                         name_len,
  int                            pshared,
  struct mq_attr                *attr,
  POSIX_Message_queue_Control  **message_queue
);

/**
 * @brief Delete a POSIX Message Queue
 *
 * This routine supports the mq_unlink and mq_close routines by
 * doing most of the work involved with removing a message queue.
 */
void _POSIX_Message_queue_Delete(
  POSIX_Message_queue_Control *the_mq
);

/*@
 *  @brief POSIX Message Queue Receive Support
 *
 *  This routine supports the various flavors of receiving a message.
 *
 *  @note The structure of the routines is identical to that of POSIX
 *        Message_queues to leave the option of having unnamed message
 *        queues at a future date.  They are currently not part of the
 *        POSIX standard but unnamed message_queues are.  This is also
 *        the reason for the apparently unnecessary tracking of
 *        the process_shared attribute.  [In addition to the fact that
 *        it would be trivial to add pshared to the mq_attr structure
 *        and have process private message queues.]
 *
 * @note This code ignores the O_RDONLY/O_WRONLY/O_RDWR flag at open time.
 */
ssize_t _POSIX_Message_queue_Receive_support(
  mqd_t               mqdes,
  char               *msg_ptr,
  size_t              msg_len,
  unsigned int       *msg_prio,
  bool                wait,
  Watchdog_Interval   timeout
);

/**
 *  @brief POSIX Message Queue Send Support
 *
 *  This routine posts a message to a specified message queue.
 */
int _POSIX_Message_queue_Send_support(
  mqd_t               mqdes,
  const char         *msg_ptr,
  size_t              msg_len,
  unsigned int        msg_prio,
  bool                wait,
  Watchdog_Interval   timeout
);

/**
 *  @brief POSIX Message Queue Allocate
 *
 *  This function allocates a message queue control block from
 *  the inactive chain of free message queue control blocks.
 */
RTEMS_INLINE_ROUTINE
  POSIX_Message_queue_Control *_POSIX_Message_queue_Allocate( void )
{
  return (POSIX_Message_queue_Control *)
    _Objects_Allocate( &_POSIX_Message_queue_Information );
}

/**
 *  @brief POSIX Message Queue Free
 *
 *  This routine frees a message queue control block to the
 *  inactive chain of free message queue control blocks.
 */
RTEMS_INLINE_ROUTINE void _POSIX_Message_queue_Free(
  POSIX_Message_queue_Control *the_mq
)
{
  _Objects_Free( &_POSIX_Message_queue_Information, &the_mq->Object );
}


/**
 *  @brief POSIX Message Queue Get
 *
 *  This function maps message queue IDs to message queue control blocks.
 *  If ID corresponds to a local message queue, then it returns
 *  the_mq control pointer which maps to ID and location
 *  is set to OBJECTS_LOCAL.  if the message queue ID is global and
 *  resides on a remote node, then location is set to OBJECTS_REMOTE,
 *  and the_message queue is undefined.  Otherwise, location is set
 *  to OBJECTS_ERROR and the_mq is undefined.
 */
RTEMS_INLINE_ROUTINE POSIX_Message_queue_Control *_POSIX_Message_queue_Get (
  Objects_Id         id,
  Objects_Locations *location
)
{
  return (POSIX_Message_queue_Control *)
    _Objects_Get( &_POSIX_Message_queue_Information, id, location );
}

/**
 *  @brief POSIX Message Queue Is NULL
 *
 *  This function returns TRUE if the_message_queue is NULL and FALSE otherwise.
 */
RTEMS_INLINE_ROUTINE bool _POSIX_Message_queue_Is_null (
  POSIX_Message_queue_Control *the_mq
)
{
  return !the_mq;
}


/*
 *  @brief POSIX Message Queue Convert Message Priority to Score
 *
 *  This method converts a POSIX message priority to the priorities used
 *  by the Score.
 */
RTEMS_INLINE_ROUTINE CORE_message_queue_Submit_types
  _POSIX_Message_queue_Priority_to_core(
  unsigned int priority
)
{
  return (CORE_message_queue_Submit_types) priority * -1;
}


/*
 *  @brief POSIX Message Queue Convert Message Priority from Score
 *
 *  This method converts a POSIX message priority from the priorities used
 *  by the Score.
 */
RTEMS_INLINE_ROUTINE unsigned int _POSIX_Message_queue_Priority_from_core(
  CORE_message_queue_Submit_types priority
)
{
  /* absolute value without a library dependency */
  return (unsigned int) ((priority >= 0) ? priority : -priority);
}

/**
 *  @brief POSIX Message Queue Translate Score Return Code
 *
 */
int _POSIX_Message_queue_Translate_core_message_queue_return_code(
  uint32_t   the_message_queue_status
);
 
/**
 *  @brief POSIX Message Queue Allocate File Descriptor
 */
RTEMS_INLINE_ROUTINE POSIX_Message_queue_Control_fd *
  _POSIX_Message_queue_Allocate_fd( void )
{
  return (POSIX_Message_queue_Control_fd *)
    _Objects_Allocate( &_POSIX_Message_queue_Information_fds );
}
 
/**
 *  @brief POSIX Message Queue Free File Descriptor
 */
RTEMS_INLINE_ROUTINE void _POSIX_Message_queue_Free_fd (
  POSIX_Message_queue_Control_fd *the_mq_fd
)
{
  _Objects_Free( &_POSIX_Message_queue_Information_fds, &the_mq_fd->Object );
}

/**
 *  @brief POSIX Message Queue Remove from Namespace
 */
RTEMS_INLINE_ROUTINE void _POSIX_Message_queue_Namespace_remove (
  POSIX_Message_queue_Control *the_mq
)
{
  _Objects_Namespace_remove( 
    &_POSIX_Message_queue_Information, &the_mq->Object );
}
 
/*
 *  @brief POSIX Message Queue Get File Descriptor
 */
RTEMS_INLINE_ROUTINE POSIX_Message_queue_Control_fd *_POSIX_Message_queue_Get_fd (
  mqd_t              id,
  Objects_Locations *location
)
{
  return (POSIX_Message_queue_Control_fd *) _Objects_Get(
    &_POSIX_Message_queue_Information_fds,
    (Objects_Id)id,
    location
  );
}
 
/**
 * @see _POSIX_Name_to_id().
 */
RTEMS_INLINE_ROUTINE int _POSIX_Message_queue_Name_to_id(
  const char          *name,
  Objects_Id          *id,
  size_t              *len
)
{
  return _POSIX_Name_to_id( &_POSIX_Message_queue_Information, name, id, len );
}

#ifdef __cplusplus
}
#endif

#endif
/*  end of include file */