mono/io-layer/mono-mutex.c

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
   2 /*
   3  * mono-mutex.h: Portability wrappers around POSIX Mutexes
   4  *
   5  * Authors: Jeffrey Stedfast <fejj@ximian.com>
   6  *
   7  * Copyright 2002 Ximian, Inc. (www.ximian.com)
   8  */
   9
  10
  11 #ifdef HAVE_CONFIG_H
  12 #include <config.h>
  13 #endif
  14
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <errno.h>
  18 #include <assert.h>
  19 #include <sys/time.h>
  20
  21 #include "mono-mutex.h"
  22
  23
  24 #ifndef HAVE_PTHREAD_MUTEX_TIMEDLOCK
  25 int pthread_mutex_timedlock (pthread_mutex_t *mutex,
  26                             const struct timespec *timeout);
  27
  28 int
  29 pthread_mutex_timedlock (pthread_mutex_t *mutex, const struct timespec *timeout)
  30 {
  31         struct timeval timenow;
  32         struct timespec sleepytime;
  33         int retcode;
  34
  35         /* This is just to avoid a completely busy wait */
  36         sleepytime.tv_sec = 0;
  37         sleepytime.tv_nsec = 10000000;  /* 10ms */
  38
  39         while ((retcode = pthread_mutex_trylock (mutex)) == EBUSY) {
  40                 gettimeofday (&timenow, NULL);
  41
  42                 if (timenow.tv_sec >= timeout->tv_sec &&
  43                     (timenow.tv_usec * 1000) >= timeout->tv_nsec) {
  44                         return ETIMEDOUT;
  45                 }
  46
  47                 nanosleep (&sleepytime, NULL);
  48         }
  49
  50         return retcode;
  51 }
  52 #endif /* HAVE_PTHREAD_MUTEX_TIMEDLOCK */
  53
  54
  55 int
  56 mono_once (mono_once_t *once, void (*once_init) (void))
  57 {
  58         int thr_ret;
  59
  60         if (!once->complete) {
  61                 pthread_cleanup_push ((void(*)(void *))pthread_mutex_unlock,
  62                                       (void *)&once->mutex);
  63                 thr_ret = pthread_mutex_lock (&once->mutex);
  64                 g_assert (thr_ret == 0);
  65
  66                 if (!once->complete) {
  67                         once_init ();
  68                         once->complete = TRUE;
  69                 }
  70                 thr_ret = pthread_mutex_unlock (&once->mutex);
  71                 g_assert (thr_ret == 0);
  72
  73                 pthread_cleanup_pop (0);
  74         }
  75
  76         return 0;
  77 }
  78
  79
  80 #ifdef USE_MONO_MUTEX
  81
  82 int
  83 mono_mutexattr_init (mono_mutexattr_t *attr)
  84 {
  85         memset (attr, 0, sizeof (mono_mutexattr_t));
  86         return 0;
  87 }
  88
  89 int
  90 mono_mutexattr_settype (mono_mutexattr_t *attr, int type)
  91 {
  92         attr->type = type;
  93         return 0;
  94 }
  95
  96 int
  97 mono_mutexattr_gettype (mono_mutexattr_t *attr, int *type)
  98 {
  99         *type = attr->type;
 100         return 0;
 101 }
 102
 103 int
 104 mono_mutexattr_setpshared (mono_mutexattr_t *attr, int pshared)
 105 {
 106         attr->shared = pshared;
 107         return 0;
 108 }
 109
 110 int
 111 mono_mutexattr_getpshared (mono_mutexattr_t *attr, int *pshared)
 112 {
 113         *pshared = attr->shared;
 114         return 0;
 115 }
 116
 117 int
 118 mono_mutexattr_setprotocol (mono_mutexattr_t *attr, int protocol)
 119 {
 120         attr->protocol = protocol;
 121         return 0;
 122 }
 123
 124 int
 125 mono_mutexattr_getprotocol (mono_mutexattr_t *attr, int *protocol)
 126 {
 127         *protocol = attr->protocol;
 128         return 0;
 129 }
 130
 131 int
 132 mono_mutexattr_setprioceiling (mono_mutexattr_t *attr, int prioceiling)
 133 {
 134         attr->priority = prioceiling;
 135         return 0;
 136 }
 137
 138 int
 139 mono_mutexattr_getprioceiling (mono_mutexattr_t *attr, int *prioceiling)
 140 {
 141         *prioceiling = attr->priority;
 142         return 0;
 143 }
 144
 145 int
 146 mono_mutexattr_destroy (mono_mutexattr_t *attr)
 147 {
 148         return 0;
 149 }
 150
 151
 152 int
 153 mono_mutex_init (mono_mutex_t *mutex, const mono_mutexattr_t *attr)
 154 {
 155         int ret;
 156         int thr_ret;
 157
 158         mutex->waiters = 0;
 159         mutex->depth = 0;
 160         mutex->owner = MONO_THREAD_NONE;
 161
 162         if (!attr || attr->type == MONO_MUTEX_NORMAL) {
 163                 mutex->type = MONO_MUTEX_NORMAL;
 164                 ret = pthread_mutex_init (&mutex->mutex, NULL);
 165         } else {
 166                 mutex->type = MONO_MUTEX_RECURSIVE;
 167                 ret = pthread_mutex_init (&mutex->mutex, NULL);
 168                 thr_ret = pthread_cond_init (&mutex->cond, NULL);
 169                 g_assert (thr_ret == 0);
 170         }
 171
 172         return(ret);
 173 }
 174
 175 int
 176 mono_mutex_lock (mono_mutex_t *mutex)
 177 {
 178         pthread_t id;
 179
 180         switch (mutex->type) {
 181         case MONO_MUTEX_NORMAL:
 182                 return pthread_mutex_lock (&mutex->mutex);
 183         case MONO_MUTEX_RECURSIVE:
 184                 id = pthread_self ();
 185                 if (pthread_mutex_lock (&mutex->mutex) != 0)
 186                         return EINVAL;
 187
 188                 while (1) {
 189                         if (pthread_equal (mutex->owner, MONO_THREAD_NONE)) {
 190                                 mutex->owner = id;
 191                                 mutex->depth = 1;
 192                                 break;
 193                         } else if (pthread_equal (mutex->owner, id)) {
 194                                 mutex->depth++;
 195                                 break;
 196                         } else {
 197                                 mutex->waiters++;
 198                                 if (pthread_cond_wait (&mutex->cond, &mutex->mutex) != 0)
 199                                         return EINVAL;
 200                                 mutex->waiters--;
 201                         }
 202                 }
 203
 204                 return pthread_mutex_unlock (&mutex->mutex);
 205         }
 206
 207         return EINVAL;
 208 }
 209
 210 int
 211 mono_mutex_trylock (mono_mutex_t *mutex)
 212 {
 213         pthread_t id;
 214
 215         switch (mutex->type) {
 216         case MONO_MUTEX_NORMAL:
 217                 return pthread_mutex_trylock (&mutex->mutex);
 218         case MONO_MUTEX_RECURSIVE:
 219                 id = pthread_self ();
 220
 221                 if (pthread_mutex_lock (&mutex->mutex) != 0)
 222                         return EINVAL;
 223
 224                 if (!pthread_equal (mutex->owner, MONO_THREAD_NONE) &&
 225                     !pthread_equal (mutex->owner, id)) {
 226                         pthread_mutex_unlock (&mutex->mutex);
 227                         return EBUSY;
 228                 }
 229
 230                 while (1) {
 231                         if (pthread_equal (mutex->owner, MONO_THREAD_NONE)) {
 232                                 mutex->owner = id;
 233                                 mutex->depth = 1;
 234                                 break;
 235                         } else {
 236                                 mutex->depth++;
 237                                 break;
 238                         }
 239                 }
 240
 241                 return pthread_mutex_unlock (&mutex->mutex);
 242         }
 243
 244         return EINVAL;
 245 }
 246
 247 int
 248 mono_mutex_timedlock (mono_mutex_t *mutex, const struct timespec *timeout)
 249 {
 250         pthread_t id;
 251
 252         switch (mutex->type) {
 253         case MONO_MUTEX_NORMAL:
 254                 return pthread_mutex_timedlock (&mutex->mutex, timeout);
 255         case MONO_MUTEX_RECURSIVE:
 256                 id = pthread_self ();
 257
 258                 if (pthread_mutex_timedlock (&mutex->mutex, timeout) != 0)
 259                         return ETIMEDOUT;
 260
 261                 while (1) {
 262                         if (pthread_equal (mutex->owner, MONO_THREAD_NONE)) {
 263                                 mutex->owner = id;
 264                                 mutex->depth = 1;
 265                                 break;
 266                         } else if (pthread_equal (mutex->owner, id)) {
 267                                 mutex->depth++;
 268                                 break;
 269                         } else {
 270                                 mutex->waiters++;
 271                                 if (pthread_cond_timedwait (&mutex->cond, &mutex->mutex, timeout) != 0)
 272                                         return ETIMEDOUT;
 273                                 mutex->waiters--;
 274                         }
 275                 }
 276
 277                 return pthread_mutex_unlock (&mutex->mutex);
 278         }
 279
 280         return EINVAL;
 281 }
 282
 283 int
 284 mono_mutex_unlock (mono_mutex_t *mutex)
 285 {
 286         int thr_ret;
 287
 288         switch (mutex->type) {
 289         case MONO_MUTEX_NORMAL:
 290                 return pthread_mutex_unlock (&mutex->mutex);
 291         case MONO_MUTEX_RECURSIVE:
 292                 if (pthread_mutex_lock (&mutex->mutex) != 0)
 293                         return EINVAL;
 294
 295                 if (pthread_equal (mutex->owner, pthread_self())) {
 296                         /* Not owned by this thread */
 297                         pthread_mutex_unlock (&mutex->mutex);
 298                         return EPERM;
 299                 }
 300
 301                 mutex->depth--;
 302                 if (mutex->depth == 0) {
 303                         mutex->owner = MONO_THREAD_NONE;
 304                         if (mutex->waiters > 0) {
 305                                 thr_ret = pthread_cond_signal (&mutex->cond);
 306                                 g_assert (thr_ret == 0);
 307                         }
 308                 }
 309
 310                 return pthread_mutex_unlock (&mutex->mutex);
 311         }
 312
 313         return EINVAL;
 314 }
 315
 316 int
 317 mono_mutex_destroy (mono_mutex_t *mutex)
 318 {
 319         int ret = 0;
 320         int thr_ret;
 321
 322         switch (mutex->type) {
 323         case MONO_MUTEX_NORMAL:
 324                 ret = pthread_mutex_destroy (&mutex->mutex);
 325                 break;
 326         case MONO_MUTEX_RECURSIVE:
 327                 if ((ret = pthread_mutex_destroy (&mutex->mutex)) == 0) {
 328                         thr_ret = pthread_cond_destroy (&mutex->cond);
 329                         g_assert (thr_ret == 0);
 330                 }
 331         }
 332
 333         return ret;
 334 }
 335
 336
 337 int
 338 mono_cond_wait (pthread_cond_t *cond, mono_mutex_t *mutex)
 339 {
 340         return pthread_cond_wait (cond, &mutex->mutex);
 341 }
 342
 343 int
 344 mono_cond_timedwait (pthread_cond_t *cond, mono_mutex_t *mutex, const struct timespec *timeout)
 345 {
 346         return pthread_cond_timedwait (cond, &mutex->mutex, timeout);
 347 }
 348
 349 #endif /* USE_MONO_MUTEX */