path: root/cpukit/score/src/objectgetnext.c

/**
 * @file
 *
 * @brief Get Pointer to Next Object that is Active
 * @ingroup ScoreObject
 */

/*
 *  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.rtems.org/license/LICENSE.
 */

#if HAVE_CONFIG_H
#include "config.h"
#endif

#include <rtems/score/objectimpl.h>

Objects_Control *_Objects_Get_next(
  Objects_Id                 id,
  const Objects_Information *information,
  Objects_Id                *next_id_p
)
{
    Objects_Control *the_object;
    Objects_Id       next_id;

    if ( !information )
      return NULL;

    if ( !next_id_p )
      return NULL;

    if (_Objects_Get_index(id) == OBJECTS_ID_INITIAL_INDEX)
        next_id = information->minimum_id;
    else
        next_id = id;

    _Objects_Allocator_lock();

    do {
        /* walked off end of list? */
        if (_Objects_Get_index(next_id) > information->maximum)
        {
            _Objects_Allocator_unlock();
            *next_id_p = OBJECTS_ID_FINAL;
            return NULL;
        }

        /* try to grab one */
        the_object = _Objects_Get_no_protection( next_id, information );

        next_id++;

    } while ( the_object == NULL );

    *next_id_p = next_id;
    return the_object;
}