summaryrefslogtreecommitdiffstats
path: root/c/src/exec/rtems/src/event.c
blob: 36c345ca8cf35b48cee8bde332fcabc5cb980b2d (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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
/*
 *  Event Manager
 *
 *  COPYRIGHT (c) 1989-1998.
 *  On-Line Applications Research Corporation (OAR).
 *  Copyright assigned to U.S. Government, 1994.
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.OARcorp.com/rtems/license.html.
 *
 *  $Id$
 */

#include <rtems/system.h>
#include <rtems/rtems/status.h>
#include <rtems/rtems/event.h>
#include <rtems/score/isr.h>
#include <rtems/score/object.h>
#include <rtems/rtems/options.h>
#include <rtems/score/states.h>
#include <rtems/score/thread.h>
#include <rtems/rtems/tasks.h>

/*PAGE
 *
 *  _Event_Manager_initialization
 *
 *  DESCRIPTION:
 *
 *  This routine performs the initialization necessary for this manager.
 */
 
void _Event_Manager_initialization( void )
{
  _Event_Sync_state = EVENT_SYNC_SYNCHRONIZED;
 
  /*
   *  Register the MP Process Packet routine.
   */
 
#if defined(RTEMS_MULTIPROCESSING)
  _MPCI_Register_packet_processor( MP_PACKET_EVENT, _Event_MP_Process_packet );
#endif
}

/*PAGE
 *
 *  rtems_event_send
 *
 *  This directive allows a thread send an event set to another thread.
 *
 *  Input parameters:
 *    id    - thread id
 *    event - event set
 *
 *  Output parameters:
 *    RTEMS_SUCCESSFUL - if successful
 *    error code - if unsuccessful
 */

rtems_status_code rtems_event_send(
  Objects_Id         id,
  rtems_event_set event_in
)
{
  register Thread_Control *the_thread;
  Objects_Locations        location;
  RTEMS_API_Control       *api;

  the_thread = _Thread_Get( id, &location );
  switch ( location ) {
    case OBJECTS_REMOTE:
#if defined(RTEMS_MULTIPROCESSING)
      return(
        _Event_MP_Send_request_packet(
          EVENT_MP_SEND_REQUEST,
          id,
          event_in
        )
      );
#endif
    case OBJECTS_ERROR:
      return RTEMS_INVALID_ID;
    case OBJECTS_LOCAL:
      api = the_thread->API_Extensions[ THREAD_API_RTEMS ];
      _Event_sets_Post( event_in, &api->pending_events );
      _Event_Surrender( the_thread );
      _Thread_Enable_dispatch();
      return RTEMS_SUCCESSFUL;
  }

  return RTEMS_INTERNAL_ERROR;   /* unreached - only to remove warnings */
}

/*PAGE
 *
 *  rtems_event_receive
 *
 *  This directive allows a thread to receive a set of events.
 *
 *  Input parameters:
 *    event_in   - input event condition
 *    option_set - options
 *    ticks      - number of ticks to wait (0 means wait forever)
 *    event_out  - pointer to output event set
 *
 *  Output parameters:
 *    event out         - event set
 *    RTEMS_SUCCESSFUL - if successful
 *    error code        - if unsuccessful
 */

rtems_status_code rtems_event_receive(
  rtems_event_set  event_in,
  rtems_option     option_set,
  rtems_interval   ticks,
  rtems_event_set *event_out
)
{
  RTEMS_API_Control       *api;

  api = _Thread_Executing->API_Extensions[ THREAD_API_RTEMS ];

  if ( _Event_sets_Is_empty( event_in ) ) {
    *event_out = api->pending_events;
    return RTEMS_SUCCESSFUL;
  }

  _Thread_Disable_dispatch();
  _Event_Seize( event_in, option_set, ticks, event_out );
  _Thread_Enable_dispatch();
  return( _Thread_Executing->Wait.return_code );
}


/*PAGE
 *
 *  _Event_Seize
 *
 *  This routine attempts to satisfy the requested event condition
 *  for the running thread.
 *
 *  Input parameters:
 *    event_in   - the event condition to satisfy
 *    option_set - acquire event options
 *    ticks      - interval to wait
 *    event_out  - pointer to event set output area
 *
 *  Output parameters: NONE
 *    *event_out - event set output area filled in
 *
 *  INTERRUPT LATENCY:
 *    available
 *    wait
 *    check sync
 */

void _Event_Seize(
  rtems_event_set  event_in,
  rtems_option     option_set,
  rtems_interval   ticks,
  rtems_event_set *event_out
)
{
  Thread_Control    *executing;
  rtems_event_set    seized_events;
  rtems_event_set    pending_events;
  ISR_Level          level;
  RTEMS_API_Control  *api;
  Event_Sync_states   sync_state;

  executing = _Thread_Executing;
  executing->Wait.return_code = RTEMS_SUCCESSFUL;

  api = executing->API_Extensions[ THREAD_API_RTEMS ];

  _ISR_Disable( level );
  pending_events = api->pending_events;
  seized_events  = _Event_sets_Get( pending_events, event_in );

  if ( !_Event_sets_Is_empty( seized_events ) &&
       (seized_events == event_in || _Options_Is_any( option_set )) ) {
    api->pending_events =
      _Event_sets_Clear( pending_events, seized_events );
    _ISR_Enable( level );
    *event_out = seized_events;
    return;
  }

  if ( _Options_Is_no_wait( option_set ) ) {
    _ISR_Enable( level );
    executing->Wait.return_code = RTEMS_UNSATISFIED;
    *event_out = seized_events;
    return;
  }

  _Event_Sync_state = EVENT_SYNC_NOTHING_HAPPENED;

  executing->Wait.option            = (unsigned32) option_set;
  executing->Wait.count             = (unsigned32) event_in;
  executing->Wait.return_argument   = event_out;

  _ISR_Enable( level );

  if ( ticks ) {
    _Watchdog_Initialize(
      &executing->Timer,
      _Event_Timeout,
      executing->Object.id,
      NULL
    );
    _Watchdog_Insert_ticks( &executing->Timer, ticks );
  }

  _Thread_Set_state( executing, STATES_WAITING_FOR_EVENT );

  _ISR_Disable( level );

  sync_state = _Event_Sync_state;
  _Event_Sync_state = EVENT_SYNC_SYNCHRONIZED;

  switch ( sync_state ) {
    case EVENT_SYNC_SYNCHRONIZED:
      /*
       *  This cannot happen.  It indicates that this routine did not
       *  enter the synchronization states above.
       */
      return;

    case EVENT_SYNC_NOTHING_HAPPENED:
      _ISR_Enable( level );
      return;

    case EVENT_SYNC_TIMEOUT:
      executing->Wait.return_code = RTEMS_TIMEOUT;
      _ISR_Enable( level );
      _Thread_Unblock( executing );
      return;

    case EVENT_SYNC_SATISFIED:
      if ( _Watchdog_Is_active( &executing->Timer ) ) {
        _Watchdog_Deactivate( &executing->Timer );
        _ISR_Enable( level );
        (void) _Watchdog_Remove( &executing->Timer );
      } else
        _ISR_Enable( level );
      _Thread_Unblock( executing );
      return;
  }
}

/*PAGE
 *
 *  _Event_Surrender
 *
 *  This routines remove a thread from the specified threadq.
 *
 *  Input parameters:
 *    the_thread - pointer to thread to be dequeued
 *
 *  Output parameters: NONE
 *
 *  INTERRUPT LATENCY:
 *    before flash
 *    after flash
 *    check sync
 */

void _Event_Surrender(
  Thread_Control *the_thread
)
{
  ISR_Level           level;
  rtems_event_set     pending_events;
  rtems_event_set     event_condition;
  rtems_event_set     seized_events;
  rtems_option        option_set;
  RTEMS_API_Control  *api;

  api = the_thread->API_Extensions[ THREAD_API_RTEMS ];

  option_set = (rtems_option) the_thread->Wait.option;

  _ISR_Disable( level );
  pending_events  = api->pending_events;
  event_condition = (rtems_event_set) the_thread->Wait.count;

  seized_events = _Event_sets_Get( pending_events, event_condition );

  if ( !_Event_sets_Is_empty( seized_events ) ) {
    if ( _States_Is_waiting_for_event( the_thread->current_state ) ) {
      if ( seized_events == event_condition || _Options_Is_any( option_set ) ) {
        api->pending_events =
           _Event_sets_Clear( pending_events, seized_events );
        *(rtems_event_set *)the_thread->Wait.return_argument = seized_events;

        _ISR_Flash( level );

        if ( !_Watchdog_Is_active( &the_thread->Timer ) ) {
          _ISR_Enable( level );
          _Thread_Unblock( the_thread );
        }
        else {
          _Watchdog_Deactivate( &the_thread->Timer );
          _ISR_Enable( level );
          (void) _Watchdog_Remove( &the_thread->Timer );
          _Thread_Unblock( the_thread );
        }
        return;
      }
    }

    switch ( _Event_Sync_state ) {
      case EVENT_SYNC_SYNCHRONIZED:
      case EVENT_SYNC_SATISFIED:
        break;
 
      case EVENT_SYNC_NOTHING_HAPPENED:
      case EVENT_SYNC_TIMEOUT:
        if ( !_Thread_Is_executing( the_thread ) )
          break;

        if ( seized_events == event_condition || _Options_Is_any(option_set) ) {
          api->pending_events = 
               _Event_sets_Clear( pending_events,seized_events );
          *(rtems_event_set *)the_thread->Wait.return_argument = seized_events;
          _Event_Sync_state = EVENT_SYNC_SATISFIED;
        }
        break;
    }
  }
  _ISR_Enable( level );
}

/*PAGE
 *
 *  _Event_Timeout
 *
 *  This routine processes a thread which timeouts while waiting to
 *  receive an event_set. It is called by the watchdog handler.
 *
 *  Input parameters:
 *    id - thread id
 *
 *  Output parameters: NONE
 */

void _Event_Timeout(
  Objects_Id  id,
  void       *ignored
)
{
  Thread_Control *the_thread;
  Objects_Locations      location;

  the_thread = _Thread_Get( id, &location );
  switch ( location ) {
    case OBJECTS_REMOTE:  /* impossible */
    case OBJECTS_ERROR:
      break;
    case OBJECTS_LOCAL:
 
      /*
       *  If the event manager is not synchronized, then it is either
       *  "nothing happened", "timeout", or "satisfied".   If the_thread
       *  is the executing thread, then it is in the process of blocking
       *  and it is the thread which is responsible for the synchronization 
       *  process.
       *
       *  If it is not satisfied, then it is "nothing happened" and
       *  this is the "timeout" transition.  After a request is satisfied,
       *  a timeout is not allowed to occur.
       */

      if ( _Event_Sync_state != EVENT_SYNC_SYNCHRONIZED && 
           _Thread_Is_executing( the_thread ) ) {
        if ( _Event_Sync_state != EVENT_SYNC_SATISFIED )
          _Event_Sync_state = EVENT_SYNC_TIMEOUT;
      } else {
        the_thread->Wait.return_code = RTEMS_TIMEOUT;
        _Thread_Unblock( the_thread );
      }
      _Thread_Unnest_dispatch();
      break;
  }
}