source: rtems/cpukit/score/src/coresemseize.c @ a8eed23

4.104.114.84.95
Last change on this file since a8eed23 was a8eed23, checked in by Ralf Corsepius <ralf.corsepius@…>, on Jan 27, 2005 at 5:57:05 AM

Include config.h.

  • Property mode set to 100644
File size: 2.1 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_Seize
37 *
38 *  This routine attempts to allocate a core semaphore to the calling thread.
39 *
40 *  Input parameters:
41 *    the_semaphore - pointer to semaphore control block
42 *    id            - id of object to wait on
43 *    wait          - TRUE if wait is allowed, FALSE otherwise
44 *    timeout       - number of ticks to wait (0 means forever)
45 *
46 *  Output parameters:  NONE
47 *
48 *  INTERRUPT LATENCY:
49 *    available
50 *    wait
51 */
52
53void _CORE_semaphore_Seize(
54  CORE_semaphore_Control  *the_semaphore,
55  Objects_Id               id,
56  boolean                  wait,
57  Watchdog_Interval        timeout
58)
59{
60  Thread_Control *executing;
61  ISR_Level       level;
62
63  executing = _Thread_Executing;
64  executing->Wait.return_code = CORE_SEMAPHORE_STATUS_SUCCESSFUL;
65  _ISR_Disable( level );
66  if ( the_semaphore->count != 0 ) {
67    the_semaphore->count -= 1;
68    _ISR_Enable( level );
69    return;
70  }
71
72  if ( !wait ) {
73    _ISR_Enable( level );
74    executing->Wait.return_code = CORE_SEMAPHORE_STATUS_UNSATISFIED_NOWAIT;
75    return;
76  }
77
78  _Thread_queue_Enter_critical_section( &the_semaphore->Wait_queue );
79  executing->Wait.queue          = &the_semaphore->Wait_queue;
80  executing->Wait.id             = id;
81  _ISR_Enable( level );
82
83  _Thread_queue_Enqueue( &the_semaphore->Wait_queue, timeout );
84}
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