source: rtems/cpukit/posix/src/prwlockrdlock.c @ c499856

4.115
Last change on this file since c499856 was c499856, checked in by Chris Johns <chrisj@…>, on 03/20/14 at 21:10:47

Change all references of rtems.com to rtems.org.

  • Property mode set to 100644
File size: 1.5 KB
Line 
1/**
2 * @file
3 *
4 * @brief Obtain a Read Lock on a RWLock Instance
5 * @ingroup POSIXAPI
6 */
7
8/*
9 *  COPYRIGHT (c) 1989-2007.
10 *  On-Line Applications Research Corporation (OAR).
11 *
12 *  The license and distribution terms for this file may be
13 *  found in the file LICENSE in this distribution or at
14 *  http://www.rtems.org/license/LICENSE.
15 */
16
17#if HAVE_CONFIG_H
18#include "config.h"
19#endif
20
21#include <pthread.h>
22#include <errno.h>
23
24#include <rtems/posix/rwlockimpl.h>
25#include <rtems/score/thread.h>
26
27/**
28 * This directive attempts to obtain a read only lock on an rwlock instance.
29 *
30 * @param[in] rwlock is the pointer to rwlock id
31 *
32 * @retval 0 if successful
33 * @retval error_code if unsuccessful
34 */
35
36int pthread_rwlock_rdlock(
37  pthread_rwlock_t  *rwlock
38)
39{
40  POSIX_RWLock_Control  *the_rwlock;
41  Objects_Locations      location;
42  Thread_Control        *executing;
43
44  if ( !rwlock )
45    return EINVAL;
46
47  the_rwlock = _POSIX_RWLock_Get( rwlock, &location );
48  switch ( location ) {
49
50    case OBJECTS_LOCAL:
51
52      executing = _Thread_Executing;
53      _CORE_RWLock_Obtain_for_reading(
54        &the_rwlock->RWLock,
55        executing,
56        *rwlock,
57        true,                 /* we are willing to wait forever */
58        0,
59        NULL
60      );
61
62      _Objects_Put( &the_rwlock->Object );
63      return _POSIX_RWLock_Translate_core_RWLock_return_code(
64        (CORE_RWLock_Status) executing->Wait.return_code
65      );
66
67#if defined(RTEMS_MULTIPROCESSING)
68    case OBJECTS_REMOTE:
69#endif
70    case OBJECTS_ERROR:
71      break;
72  }
73
74  return EINVAL;
75}
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