summaryrefslogtreecommitdiffstats
path: root/c/src/exec/posix/src/cond.c
blob: bba0f1991fccc706f863b63798a972ed3cf343b5 (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
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
/*
 *  $Id$
 */

#include <pthread.h>
#include <errno.h>

#include <rtems/system.h>
#include <rtems/score/object.h>
#include <rtems/score/states.h>
#include <rtems/score/watchdog.h>
#include <rtems/posix/cond.h>
#include <rtems/posix/time.h>

/*
 *  TEMPORARY
 */

void _POSIX_Condition_variables_MP_Send_process_packet (
  POSIX_Condition_variables_MP_Remote_operations  operation,
  Objects_Id                        condition_variables_id,
  Objects_Name                      name,
  Objects_Id                        proxy_id
)
{
  (void) POSIX_MP_NOT_IMPLEMENTED();
}

void _POSIX_Condition_variables_MP_Send_extract_proxy(
  Thread_Control *the_thread
)
{
  (void) POSIX_MP_NOT_IMPLEMENTED();
}

/*
 *  END OF TEMPORARY
 */

/*PAGE
 *
 *  The default condition variable attributes structure.
 */
 
const pthread_condattr_t _POSIX_Condition_variables_Default_attributes = {
  TRUE,                      /* is_initialized */
  PTHREAD_PROCESS_PRIVATE    /* process_shared */
};
 
/*PAGE
 *
 *  _POSIX_Condition_variables_Manager_initialization
 *
 *  This routine initializes all condition variable manager related data 
 *  structures.
 *
 *  Input parameters:
 *    maximum_condition_variables - maximum configured condition_variables
 *
 *  Output parameters:  NONE
 */
 
void _POSIX_Condition_variables_Manager_initialization(
  unsigned32 maximum_condition_variables
)
{
  _Objects_Initialize_information(
    &_POSIX_Condition_variables_Information,
    OBJECTS_POSIX_CONDITION_VARIABLES,
    TRUE,
    maximum_condition_variables,
    sizeof( POSIX_Condition_variables_Control ),
    FALSE,
    0,
    FALSE
  );
}

/*PAGE
 *
 *  11.4.1 Condition Variable Initialization Attributes, 
 *            P1003.1c/Draft 10, p. 96
 */
 
int pthread_condattr_init(
  pthread_condattr_t *attr
)
{
  if ( !attr )
    return EINVAL;

  *attr = _POSIX_Condition_variables_Default_attributes;
  return 0;
}
 
/*PAGE
 *
 *  11.4.1 Condition Variable Initialization Attributes, 
 *            P1003.1c/Draft 10, p. 96
 */
 
int pthread_condattr_destroy(
  pthread_condattr_t *attr
)
{
  if ( !attr || attr->is_initialized == FALSE )
    return EINVAL;

  attr->is_initialized = FALSE;
  return 0;
}
 
/*PAGE
 *
 *  11.4.1 Condition Variable Initialization Attributes, 
 *            P1003.1c/Draft 10, p. 96
 */
 
int pthread_condattr_getpshared(
  const pthread_condattr_t *attr,
  int                      *pshared
)
{
  if ( !attr )
    return EINVAL;

  *pshared = attr->process_shared;
  return 0;
}
 
/*PAGE
 *
 *  11.4.1 Condition Variable Initialization Attributes, 
 *            P1003.1c/Draft 10, p. 96
 */
 
int pthread_condattr_setpshared(
  pthread_condattr_t *attr,
  int                 pshared
)
{
  if ( !attr )
    return EINVAL;

  attr->process_shared = pshared;
  return 0;
}
 
/*PAGE
 *
 *  11.4.2 Initializing and Destroying a Condition Variable, 
 *         P1003.1c/Draft 10, p. 87
 */
 
int pthread_cond_init(
  pthread_cond_t           *cond,
  const pthread_condattr_t *attr
)
{
  POSIX_Condition_variables_Control   *the_cond;
  const pthread_condattr_t            *the_attr;
 
  if ( attr ) the_attr = attr;
  else        the_attr = &_POSIX_Condition_variables_Default_attributes;
 
  /*
   *  XXX: Be careful about attributes when global!!!
   */
 
  if ( the_attr->process_shared == PTHREAD_PROCESS_SHARED )
    return POSIX_MP_NOT_IMPLEMENTED();
 
  if ( !the_attr->is_initialized )
    return EINVAL;
 
  _Thread_Disable_dispatch();
 
  the_cond = _POSIX_Condition_variables_Allocate();
 
  if ( !the_cond ) {
    _Thread_Enable_dispatch();
    return ENOMEM;
  }
 
  if ( the_attr->process_shared == PTHREAD_PROCESS_SHARED &&
     !( _Objects_MP_Allocate_and_open( &_POSIX_Condition_variables_Information,
                0, the_cond->Object.id, FALSE ) ) ) {
    _POSIX_Condition_variables_Free( the_cond );
    _Thread_Enable_dispatch();
    return EAGAIN;
  }
 
  the_cond->process_shared  = the_attr->process_shared;

  the_cond->Mutex = 0;

/* XXX some more initialization might need to go here */
  _Thread_queue_Initialize(
    &the_cond->Wait_queue,
    OBJECTS_POSIX_CONDITION_VARIABLES,
    THREAD_QUEUE_DISCIPLINE_FIFO,
    STATES_WAITING_FOR_CONDITION_VARIABLE,
    _POSIX_Condition_variables_MP_Send_extract_proxy,
    ETIMEDOUT
  );

  _Objects_Open(
    &_POSIX_Condition_variables_Information,
    &the_cond->Object,
    0
  );
 
  *cond = the_cond->Object.id;
 
  if ( the_attr->process_shared == PTHREAD_PROCESS_SHARED )
    _POSIX_Condition_variables_MP_Send_process_packet(
      POSIX_CONDITION_VARIABLES_MP_ANNOUNCE_CREATE,
      the_cond->Object.id,
      0,                         /* Name not used */
      0                          /* Not used */
    );
 
  _Thread_Enable_dispatch();

  return 0;
}
 
/*PAGE
 *
 *  11.4.2 Initializing and Destroying a Condition Variable, 
 *         P1003.1c/Draft 10, p. 87
 */
 
int pthread_cond_destroy(
  pthread_cond_t           *cond
)
{
  register POSIX_Condition_variables_Control *the_cond;
  Objects_Locations                           location;
 
  the_cond = _POSIX_Condition_variables_Get( cond, &location );
  switch ( location ) {
    case OBJECTS_ERROR:
      return EINVAL;
    case OBJECTS_REMOTE:
      _Thread_Dispatch();
      return POSIX_MP_NOT_IMPLEMENTED();
      return EINVAL;
    case OBJECTS_LOCAL:
 
      _Objects_Close(
        &_POSIX_Condition_variables_Information,
        &the_cond->Object
      );
 
      if ( _Thread_queue_Get_number_waiting( &the_cond->Wait_queue ) ) 
        return EBUSY;
 
      _POSIX_Condition_variables_Free( the_cond );
 
      if ( the_cond->process_shared == PTHREAD_PROCESS_SHARED ) {
 
        _Objects_MP_Close(
          &_POSIX_Condition_variables_Information,
          the_cond->Object.id
        );
 
        _POSIX_Condition_variables_MP_Send_process_packet(
          POSIX_CONDITION_VARIABLES_MP_ANNOUNCE_DELETE,
          the_cond->Object.id,
          0,                         /* Not used */
          0                          /* Not used */
        );
      }
      _Thread_Enable_dispatch();
      return 0;
  }
  return POSIX_BOTTOM_REACHED();
}
 
/*PAGE
 *
 *  _POSIX_Condition_variables_Signal_support
 *
 *  A support routine which implements guts of the broadcast and single task
 *  wake up version of the "signal" operation.
 */
 
int _POSIX_Condition_variables_Signal_support(
  pthread_cond_t            *cond,
  boolean                    is_broadcast
)
{
  register POSIX_Condition_variables_Control *the_cond;
  Objects_Locations                           location;
  Thread_Control                             *the_thread;
 
  the_cond = _POSIX_Condition_variables_Get( cond, &location );
  switch ( location ) {
    case OBJECTS_ERROR:
      return EINVAL;
    case OBJECTS_REMOTE:
      _Thread_Dispatch();
      return POSIX_MP_NOT_IMPLEMENTED();
      return EINVAL;
    case OBJECTS_LOCAL:
 
      do { 
        the_thread = _Thread_queue_Dequeue( &the_cond->Wait_queue );
      } while ( is_broadcast && the_thread );
      return 0;
  }
  return POSIX_BOTTOM_REACHED();
}

/*PAGE
 *
 *  11.4.3 Broadcasting and Signaling a Condition, P1003.1c/Draft 10, p. 101
 */
 
int pthread_cond_signal(
  pthread_cond_t   *cond
)
{
  return _POSIX_Condition_variables_Signal_support( cond, FALSE );
}
 
/*PAGE
 *
 *  11.4.3 Broadcasting and Signaling a Condition, P1003.1c/Draft 10, p. 101
 */
 
int pthread_cond_broadcast(
  pthread_cond_t   *cond
)
{
  return _POSIX_Condition_variables_Signal_support( cond, TRUE );
}
 
/*PAGE
 *
 *  _POSIX_Condition_variables_Wait_support
 *
 *  A support routine which implements guts of the blocking, non-blocking, and
 *  timed wait version of condition variable wait routines.
 */
 
int _POSIX_Condition_variables_Wait_support(
  pthread_cond_t            *cond,
  pthread_mutex_t           *mutex,
  Watchdog_Interval          timeout
)
{
  register POSIX_Condition_variables_Control *the_cond;
  Objects_Locations                           location;
  int                                         status;
 
  the_cond = _POSIX_Condition_variables_Get( cond, &location );
  switch ( location ) {
    case OBJECTS_ERROR:
      return EINVAL;
    case OBJECTS_REMOTE:
      _Thread_Dispatch();
      return POSIX_MP_NOT_IMPLEMENTED();
      return EINVAL;
    case OBJECTS_LOCAL:
 
      /*
       *  XXX: should be an error if cond->Mutex != mutex
       */
 
      status = pthread_mutex_unlock( mutex );
      if ( !status )
        return status;
 
      the_cond->Mutex = *mutex;
 
/* XXX .. enter critical section .. */
      _Thread_queue_Enqueue( &the_cond->Wait_queue, 0 );

      _Thread_Enable_dispatch();

      status = pthread_mutex_lock( mutex );
      if ( !status )
        return status;
    
      return _Thread_Executing->Wait.return_code;
  }
  return POSIX_BOTTOM_REACHED();
}

/*PAGE
 *
 *  11.4.4 Waiting on a Condition, P1003.1c/Draft 10, p. 105
 */
 
int pthread_cond_wait(
  pthread_cond_t     *cond,
  pthread_mutex_t    *mutex
)
{
  return _POSIX_Condition_variables_Wait_support(
    cond,
    mutex,
    THREAD_QUEUE_WAIT_FOREVER
  );
}
 
/*PAGE
 *
 *  11.4.4 Waiting on a Condition, P1003.1c/Draft 10, p. 105
 */
 
int pthread_cond_timedwait(
  pthread_cond_t        *cond,
  pthread_mutex_t       *mutex,
  const struct timespec *abstime
)
{
  return _POSIX_Condition_variables_Wait_support(
    cond,
    mutex,
    _POSIX_Time_Spec_to_interval( abstime )
  );
}