source: rtems/cpukit/posix/src/mqueuereceive.c @ a2cf229

4.8
Last change on this file since a2cf229 was a2cf229, checked in by Joel Sherrill <joel.sherrill@…>, on 07/22/08 at 17:17:12

2008-07-18 Joel Sherrill <joel.sherrill@…>

PR 1291/cpukit

  • itron/inline/rtems/itron/semaphore.inl, itron/src/twai_sem.c, 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/mutextimedlock.c, posix/src/mutextranslatereturncode.c, posix/src/posixtimespecabsolutetimeout.c, posix/src/prwlocktimedrdlock.c, posix/src/prwlocktimedwrlock.c, posix/src/semaphoretranslatereturncode.c, posix/src/semaphorewaitsupp.c, posix/src/semtimedwait.c, posix/src/semtrywait.c, posix/src/semwait.c, posix/src/sigtimedwait.c, posix/src/timersettime.c, posix/src/ualarm.c, rtems/src/semobtain.c, rtems/src/semtranslatereturncode.c, score/include/rtems/score/coremutex.h, score/include/rtems/score/coresem.h, 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: 1.4 KB
Line 
1/*
2 *  NOTE:  The structure of the routines is identical to that of POSIX
3 *         Message_queues to leave the option of having unnamed message
4 *         queues at a future date.  They are currently not part of the
5 *         POSIX standard but unnamed message_queues are.  This is also
6 *         the reason for the apparently unnecessary tracking of
7 *         the process_shared attribute.  [In addition to the fact that
8 *         it would be trivial to add pshared to the mq_attr structure
9 *         and have process private message queues.]
10 *
11 *         This code ignores the O_RDONLY/O_WRONLY/O_RDWR flag at open
12 *         time.
13 *
14 *  $Id$
15 */
16
17#if HAVE_CONFIG_H
18#include "config.h"
19#endif
20
21#include <stdarg.h>
22
23#include <pthread.h>
24#include <limits.h>
25#include <errno.h>
26#include <fcntl.h>
27#include <mqueue.h>
28
29#include <rtems/system.h>
30#include <rtems/score/watchdog.h>
31#include <rtems/seterr.h>
32#include <rtems/posix/mqueue.h>
33#include <rtems/posix/time.h>
34
35/*PAGE
36 *
37 *  15.2.5 Receive a Message From a Message Queue, P1003.1b-1993, p. 279
38 *
39 *  NOTE: P1003.4b/D8, p. 45 adds mq_timedreceive().
40 */
41
42ssize_t mq_receive(
43  mqd_t         mqdes,
44  char         *msg_ptr,
45  size_t        msg_len,
46  unsigned int *msg_prio
47)
48{
49  return _POSIX_Message_queue_Receive_support(
50    mqdes,
51    msg_ptr,
52    msg_len,
53    msg_prio,
54    TRUE,
55    THREAD_QUEUE_WAIT_FOREVER
56  );
57}
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