summaryrefslogtreecommitdiffstats
path: root/cpukit/posix/src/mqueuenotify.c
blob: 35a1e1decad1702f9ccee733e96c2f7646e99985 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
/*
 *  NOTE:  The structure of the routines is identical to that of POSIX
 *         Message_queues to leave the option of having unnamed message
 *         queues at a future date.  They are currently not part of the
 *         POSIX standard but unnamed message_queues are.  This is also 
 *         the reason for the apparently unnecessary tracking of 
 *         the process_shared attribute.  [In addition to the fact that
 *         it would be trivial to add pshared to the mq_attr structure
 *         and have process private message queues.]
 *
 *         This code ignores the O_RDONLY/O_WRONLY/O_RDWR flag at open
 *         time.
 *
 *  $Id$
 */

#if HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdarg.h>

#include <pthread.h>
#include <limits.h>
#include <errno.h>
#include <fcntl.h>
#include <mqueue.h>
#include <sys/types.h>
#include <signal.h>

#include <rtems/system.h>
#include <rtems/score/watchdog.h>
#include <rtems/seterr.h>
#include <rtems/posix/mqueue.h>
#include <rtems/posix/time.h>

/*PAGE
 *
 *  _POSIX_Message_queue_Notify_handler
 *
 */

void _POSIX_Message_queue_Notify_handler(
  void    *user_data
)
{
  POSIX_Message_queue_Control *the_mq;

  the_mq = user_data;

  kill( getpid(), the_mq->notification.sigev_signo );

  _CORE_message_queue_Set_notify( &the_mq->Message_queue, NULL, NULL );
}

/*PAGE
 *
 *  15.2.6 Notify Process that a Message is Available on a Queue, 
 *         P1003.1b-1993, p. 280
 */

int mq_notify(
  mqd_t                  mqdes,
  const struct sigevent *notification
)
{
  register POSIX_Message_queue_Control *the_mq;
  Objects_Locations                     location;
 
  the_mq = _POSIX_Message_queue_Get( mqdes, &location );
  switch ( location ) {
    case OBJECTS_ERROR:
      rtems_set_errno_and_return_minus_one( EBADF );
    case OBJECTS_REMOTE:
      _Thread_Dispatch();
      return POSIX_MP_NOT_IMPLEMENTED();
      rtems_set_errno_and_return_minus_one( EINVAL );
    case OBJECTS_LOCAL:
      if ( notification ) {
        if ( _CORE_message_queue_Is_notify_enabled( &the_mq->Message_queue ) ) {
          _Thread_Enable_dispatch();
          rtems_set_errno_and_return_minus_one( EBUSY );
        }

        _CORE_message_queue_Set_notify( &the_mq->Message_queue, NULL, NULL );

        the_mq->notification = *notification;
      
        _CORE_message_queue_Set_notify(
          &the_mq->Message_queue,
          _POSIX_Message_queue_Notify_handler,
          the_mq
        );
      } else {

        _CORE_message_queue_Set_notify( &the_mq->Message_queue, NULL, NULL );

      }

      _Thread_Enable_dispatch();
      return 0;
  }
  return POSIX_BOTTOM_REACHED();
}