source: rtems/cpukit/score/src/coresemsurrender.c @ 22ce0881

4.104.114.95
Last change on this file since 22ce0881 was a8eed23, checked in by Ralf Corsepius <ralf.corsepius@…>, on 01/27/05 at 05:57:05

Include config.h.

  • Property mode set to 100644
File size: 2.0 KB
Line 
1/*
2 *  CORE Semaphore Handler
3 *
4 *  DESCRIPTION:
5 *
6 *  This package is the implementation of the CORE Semaphore Handler.
7 *  This core object utilizes standard Dijkstra counting semaphores to provide
8 *  synchronization and mutual exclusion capabilities.
9 *
10 *  COPYRIGHT (c) 1989-1999.
11 *  On-Line Applications Research Corporation (OAR).
12 *
13 *  The license and distribution terms for this file may be
14 *  found in the file LICENSE in this distribution or at
15 *  http://www.rtems.com/license/LICENSE.
16 *
17 *  $Id$
18 */
19
20#if HAVE_CONFIG_H
21#include "config.h"
22#endif
23
24#include <rtems/system.h>
25#include <rtems/score/isr.h>
26#include <rtems/score/coresem.h>
27#include <rtems/score/states.h>
28#include <rtems/score/thread.h>
29#include <rtems/score/threadq.h>
30#if defined(RTEMS_MULTIPROCESSING)
31#include <rtems/score/mpci.h>
32#endif
33
34/*PAGE
35 *
36 *  _CORE_semaphore_Surrender
37 *
38 *  Input parameters:
39 *    the_semaphore            - the semaphore to be flushed
40 *    id                       - id of parent semaphore
41 *    api_semaphore_mp_support - api dependent MP support actions
42 *
43 *  Output parameters:
44 *    CORE_SEMAPHORE_STATUS_SUCCESSFUL - if successful
45 *    core error code                  - if unsuccessful
46 *
47 *  Output parameters:
48 */
49
50CORE_semaphore_Status _CORE_semaphore_Surrender(
51  CORE_semaphore_Control                *the_semaphore,
52  Objects_Id                             id,
53  CORE_semaphore_API_mp_support_callout  api_semaphore_mp_support
54)
55{
56  Thread_Control *the_thread;
57  ISR_Level       level;
58  CORE_semaphore_Status status;
59
60  status = CORE_SEMAPHORE_STATUS_SUCCESSFUL;
61
62  if ( (the_thread = _Thread_queue_Dequeue(&the_semaphore->Wait_queue)) ) {
63
64#if defined(RTEMS_MULTIPROCESSING)
65    if ( !_Objects_Is_local_id( the_thread->Object.id ) )
66      (*api_semaphore_mp_support) ( the_thread, id );
67#endif
68
69  } else {
70    _ISR_Disable( level );
71      if ( the_semaphore->count < the_semaphore->Attributes.maximum_count )
72        the_semaphore->count += 1;
73      else
74        status = CORE_SEMAPHORE_MAXIMUM_COUNT_EXCEEDED;
75    _ISR_Enable( level );
76  }
77
78  return status;
79}
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