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/*

 *  Region Manager

 *

 *

 *  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: regiongetsegment.c,v 1.2 2001-09-27 11:59:19 chris Exp $

 */

#include <rtems/system.h>

#include <rtems/rtems/status.h>

#include <rtems/rtems/support.h>

#include <rtems/score/object.h>

#include <rtems/rtems/options.h>

#include <rtems/rtems/region.h>

#include <rtems/score/states.h>

#include <rtems/score/thread.h>

/*PAGE

 *

 *  rtems_region_get_segment

 *

 *  This directive will obtain a segment from the given region.

 *

 *  Input parameters:

 *    id         - region id

 *    size       - segment size in bytes

 *    option_set - wait option

 *    timeout    - number of ticks to wait (0 means wait forever)

 *    segment    - pointer to segment address

 *

 *  Output parameters:

 *    segment    - pointer to segment address filled in

 *    RTEMS_SUCCESSFUL - if successful

 *    error code - if unsuccessful

 */

rtems_status_code rtems_region_get_segment(

  Objects_Id         id,

  unsigned32         size,

  rtems_option       option_set,

  rtems_interval     timeout,

  void              **segment

)

{

  register Region_Control *the_region;

  Objects_Locations        location;

  Thread_Control          *executing;

  void                    *the_segment;

  *segment = NULL;

  if ( size == 0 )

    return RTEMS_INVALID_SIZE;

  executing  = _Thread_Executing;

  the_region = _Region_Get( id, &location );

  switch ( location ) {

    case OBJECTS_REMOTE:        /* this error cannot be returned */

      return RTEMS_INTERNAL_ERROR;

    case OBJECTS_ERROR:

      return RTEMS_INVALID_ID;

    case OBJECTS_LOCAL:

      if ( size > the_region->maximum_segment_size ) {

        _Thread_Enable_dispatch();

        return RTEMS_INVALID_SIZE;

      }

      _Region_Debug_Walk( the_region, 1 );

      the_segment = _Region_Allocate_segment( the_region, size );

      _Region_Debug_Walk( the_region, 2 );

      if ( the_segment ) {

        the_region->number_of_used_blocks += 1;

        _Thread_Enable_dispatch();

        *segment = the_segment;

        return RTEMS_SUCCESSFUL;

      }

      if ( _Options_Is_no_wait( option_set ) ) {

        _Thread_Enable_dispatch();

        return RTEMS_UNSATISFIED;

      }

      executing->Wait.queue           = &the_region->Wait_queue;

      executing->Wait.id              = id;

      executing->Wait.count           = size;

      executing->Wait.return_argument = (unsigned32 *) segment;

      _Thread_queue_Enter_critical_section( &the_region->Wait_queue );

      _Thread_queue_Enqueue( &the_region->Wait_queue, timeout );

      _Thread_Enable_dispatch();

      return (rtems_status_code) executing->Wait.return_code;

  }

  return RTEMS_INTERNAL_ERROR;   /* unreached - only to remove warnings */

}