source: rtems/cpukit/posix/src/semtrywait.c @ d17c114

Last change on this file since d17c114 was d17c114, checked in by Joel Sherrill <joel.sherrill@…>, on 07/24/08 at 20:43:24

2008-07-24 Joel Sherrill <joel.sherrill@…>

PR 1291/cpukit

  • posix/src/posixtimespecabsolutetimeout.c: New file.
  • itron/inline/rtems/itron/semaphore.inl, itron/src/twai_sem.c, posix/Makefile.am, posix/include/mqueue.h, posix/include/rtems/posix/mqueue.h, posix/include/rtems/posix/semaphore.h, posix/include/rtems/posix/time.h, posix/src/condtimedwait.c, posix/src/mqueuereceive.c, posix/src/mqueuerecvsupp.c, posix/src/mqueuesend.c, posix/src/mqueuesendsupp.c, posix/src/mqueuetimedreceive.c, posix/src/mqueuetimedsend.c, posix/src/mutexfromcorestatus.c, posix/src/mutextimedlock.c, posix/src/semaphorewaitsupp.c, posix/src/semtimedwait.c, posix/src/semtrywait.c, posix/src/semwait.c, rtems/src/semobtain.c, rtems/src/semtranslatereturncode.c, score/include/rtems/score/coresem.h, score/src/coremsgseize.c, score/src/coresemseize.c: This patch addresses issues on implementation of the timeout on the following POSIX services. Some of these services incorrectly took a timeout as a relative time. Others would compute a 0 delta to timeout if the absolute time and the current time were equal and thus incorrectly block the caller forever. The root of the confusion is that POSIX specifies that if the timeout is incorrect (e.g. in the past, is now, or is numerically invalid), that it does not matter if the call would succeed without blocking. This is in contrast to RTEMS programming style where all errors are checked before any critical sections are entered. This fix implemented a more uniform way of handling POSIX absolute time timeouts.

+ pthread_cond_timedwait - could block forever
+ mq_timedreceive - used relative not absolute time
+ mq_timedsend - used relative not absolute time
+ pthread_mutex_timedlock - used relative not absolute time
+ pthread_rwlock_timedrdlock- used relative not absolute time
+ pthread_rwlock_timedwrlock- used relative not absolute time
+ sem_timedwait - could block forever
  • Property mode set to 100644
File size: 570 bytes
Line 
1/*
2 *  $Id$
3 */
4
5#if HAVE_CONFIG_H
6#include "config.h"
7#endif
8
9#include <stdarg.h>
10
11#include <errno.h>
12#include <fcntl.h>
13#include <pthread.h>
14#include <semaphore.h>
15#include <limits.h>
16
17#include <rtems/system.h>
18#include <rtems/score/object.h>
19#include <rtems/posix/semaphore.h>
20#include <rtems/posix/time.h>
21#include <rtems/seterr.h>
22
23/*PAGE
24 *
25 *  11.2.6 Lock a Semaphore, P1003.1b-1993, p.226
26 *
27 *  NOTE: P1003.4b/D8 adds sem_timedwait(), p. 27
28 */
29
30int sem_trywait(
31  sem_t *sem
32)
33{
34  return _POSIX_Semaphore_Wait_support(sem, FALSE, THREAD_QUEUE_WAIT_FOREVER);
35}
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