summaryrefslogtreecommitdiffstats
path: root/cpukit/score/src/coremsgsubmit.c
blob: 330f43c13e27a7af73826ee6215ba8a4f7642ef9 (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
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
/**
 * @file
 *
 * @brief CORE Message Queue Submit
 *
 * @ingroup ScoreMessageQueue
 */

/*
 *  COPYRIGHT (c) 1989-2009.
 *  On-Line Applications Research Corporation (OAR).
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.rtems.org/license/LICENSE.
 */

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

#include <rtems/score/coremsgimpl.h>
#include <rtems/score/objectimpl.h>
#include <rtems/score/isr.h>
#include <rtems/score/threadimpl.h>
#include <rtems/score/statesimpl.h>
#include <rtems/score/wkspace.h>

Status_Control _CORE_message_queue_Submit(
  CORE_message_queue_Control       *the_message_queue,
  Thread_Control                   *executing,
  const void                       *buffer,
  size_t                            size,
  CORE_message_queue_Submit_types   submit_type,
  bool                              wait,
  Thread_queue_Context             *queue_context
)
{
  CORE_message_queue_Buffer_control *the_message;
  Thread_Control                    *the_thread;

  if ( size > the_message_queue->maximum_message_size ) {
    _CORE_message_queue_Release( the_message_queue, queue_context );
    return STATUS_MESSAGE_INVALID_SIZE;
  }

  /*
   *  Is there a thread currently waiting on this message queue?
   */

  the_thread = _CORE_message_queue_Dequeue_receiver(
    the_message_queue,
    buffer,
    size,
    submit_type,
    queue_context
  );
  if ( the_thread != NULL ) {
    return STATUS_SUCCESSFUL;
  }

  /*
   *  No one waiting on the message queue at this time, so attempt to
   *  queue the message up for a future receive.
   */
  the_message =
      _CORE_message_queue_Allocate_message_buffer( the_message_queue );
  if ( the_message ) {
    _CORE_message_queue_Insert_message(
      the_message_queue,
      the_message,
      buffer,
      size,
      submit_type
    );

#if defined(RTEMS_SCORE_COREMSG_ENABLE_NOTIFICATION)
    /*
     *  According to POSIX, does this happen before or after the message
     *  is actually enqueued.  It is logical to think afterwards, because
     *  the message is actually in the queue at this point.
     */
    if (
      the_message_queue->number_of_pending_messages == 1
        && the_message_queue->notify_handler != NULL
    ) {
      ( *the_message_queue->notify_handler )(
        the_message_queue,
        queue_context
      );
    } else {
      _CORE_message_queue_Release( the_message_queue, queue_context );
    }
#else
    _CORE_message_queue_Release( the_message_queue, queue_context );
#endif

    return STATUS_SUCCESSFUL;
  }

  #if !defined(RTEMS_SCORE_COREMSG_ENABLE_BLOCKING_SEND)
    _CORE_message_queue_Release( the_message_queue, queue_context );
    return STATUS_TOO_MANY;
  #else
    /*
     *  No message buffers were available so we may need to return an
     *  overflow error or block the sender until the message is placed
     *  on the queue.
     */
    if ( !wait ) {
      _CORE_message_queue_Release( the_message_queue, queue_context );
      return STATUS_TOO_MANY;
    }

    /*
     *  Do NOT block on a send if the caller is in an ISR.  It is
     *  deadly to block in an ISR.
     */
    if ( _ISR_Is_in_progress() ) {
      _CORE_message_queue_Release( the_message_queue, queue_context );
      return STATUS_MESSAGE_QUEUE_WAIT_IN_ISR;
    }

    /*
     *  WARNING!! executing should NOT be used prior to this point.
     *  Thus the unusual choice to open a new scope and declare
     *  it as a variable.  Doing this emphasizes how dangerous it
     *  would be to use this variable prior to here.
     */
    executing->Wait.return_argument_second.immutable_object = buffer;
    executing->Wait.option = (uint32_t) size;
    executing->Wait.count = submit_type;

    _Thread_queue_Context_set_do_nothing_enqueue_callout( queue_context );
    _Thread_queue_Enqueue_critical(
      &the_message_queue->Wait_queue.Queue,
      the_message_queue->operations,
      executing,
      STATES_WAITING_FOR_MESSAGE,
      queue_context
    );
    return _Thread_Wait_get_status( executing );
  #endif
}