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 /* Android does not implement pthread_mutex_timedlock(), but does provide an
  26  * unusual declaration: http://code.google.com/p/android/issues/detail?id=7807
  27  */
  28 #ifdef PLATFORM_ANDROID
  29 #define CONST_NEEDED
  30 #else
  31 #define CONST_NEEDED const
  32 #endif
  33
  34 int pthread_mutex_timedlock (pthread_mutex_t *mutex,
  35                             CONST_NEEDED struct timespec *timeout);
  36 int
  37 pthread_mutex_timedlock (pthread_mutex_t *mutex, CONST_NEEDED struct timespec *timeout)
  38 {
  39         struct timeval timenow;
  40         struct timespec sleepytime;
  41         int retcode;
  42
  43         /* This is just to avoid a completely busy wait */
  44         sleepytime.tv_sec = 0;
  45         sleepytime.tv_nsec = 10000000;  /* 10ms */
  46
  47         while ((retcode = pthread_mutex_trylock (mutex)) == EBUSY) {
  48                 gettimeofday (&timenow, NULL);
  49
  50                 if (timenow.tv_sec >= timeout->tv_sec &&
  51                     (timenow.tv_usec * 1000) >= timeout->tv_nsec) {
  52                         return ETIMEDOUT;
  53                 }
  54
  55                 nanosleep (&sleepytime, NULL);
  56         }
  57
  58         return retcode;
  59 }
  60 #endif /* HAVE_PTHREAD_MUTEX_TIMEDLOCK */
  61
  62
  63 int
  64 mono_once (mono_once_t *once, void (*once_init) (void))
  65 {
  66         int thr_ret;
  67
  68         if (!once->complete) {
  69                 pthread_cleanup_push ((void(*)(void *))pthread_mutex_unlock,
  70                                       (void *)&once->mutex);
  71                 thr_ret = pthread_mutex_lock (&once->mutex);
  72                 g_assert (thr_ret == 0);
  73
  74                 if (!once->complete) {
  75                         once_init ();
  76                         once->complete = TRUE;
  77                 }
  78                 thr_ret = pthread_mutex_unlock (&once->mutex);
  79                 g_assert (thr_ret == 0);
  80
  81                 pthread_cleanup_pop (0);
  82         }
  83
  84         return 0;
  85 }
  86
  87
  88 #ifdef USE_MONO_MUTEX
  89
  90 int
  91 mono_mutexattr_init (mono_mutexattr_t *attr)
  92 {
  93         memset (attr, 0, sizeof (mono_mutexattr_t));
  94         return 0;
  95 }
  96
  97 int
  98 mono_mutexattr_settype (mono_mutexattr_t *attr, int type)
  99 {
 100         attr->type = type;
 101         return 0;
 102 }
 103
 104 int
 105 mono_mutexattr_gettype (mono_mutexattr_t *attr, int *type)
 106 {
 107         *type = attr->type;
 108         return 0;
 109 }
 110
 111 int
 112 mono_mutexattr_setpshared (mono_mutexattr_t *attr, int pshared)
 113 {
 114         attr->shared = pshared;
 115         return 0;
 116 }
 117
 118 int
 119 mono_mutexattr_getpshared (mono_mutexattr_t *attr, int *pshared)
 120 {
 121         *pshared = attr->shared;
 122         return 0;
 123 }
 124
 125 int
 126 mono_mutexattr_setprotocol (mono_mutexattr_t *attr, int protocol)
 127 {
 128         attr->protocol = protocol;
 129         return 0;
 130 }
 131
 132 int
 133 mono_mutexattr_getprotocol (mono_mutexattr_t *attr, int *protocol)
 134 {
 135         *protocol = attr->protocol;
 136         return 0;
 137 }
 138
 139 int
 140 mono_mutexattr_setprioceiling (mono_mutexattr_t *attr, int prioceiling)
 141 {
 142         attr->priority = prioceiling;
 143         return 0;
 144 }
 145
 146 int
 147 mono_mutexattr_getprioceiling (mono_mutexattr_t *attr, int *prioceiling)
 148 {
 149         *prioceiling = attr->priority;
 150         return 0;
 151 }
 152
 153 int
 154 mono_mutexattr_destroy (mono_mutexattr_t *attr)
 155 {
 156         return 0;
 157 }
 158
 159
 160 int
 161 mono_mutex_init (mono_mutex_t *mutex, const mono_mutexattr_t *attr)
 162 {
 163         int ret;
 164         int thr_ret;
 165
 166         mutex->waiters = 0;
 167         mutex->depth = 0;
 168         mutex->owner = MONO_THREAD_NONE;
 169
 170         if (!attr || attr->type == MONO_MUTEX_NORMAL) {
 171                 mutex->type = MONO_MUTEX_NORMAL;
 172                 ret = pthread_mutex_init (&mutex->mutex, NULL);
 173         } else {
 174                 mutex->type = MONO_MUTEX_RECURSIVE;
 175                 ret = pthread_mutex_init (&mutex->mutex, NULL);
 176                 thr_ret = pthread_cond_init (&mutex->cond, NULL);
 177                 g_assert (thr_ret == 0);
 178         }
 179
 180         return(ret);
 181 }
 182
 183 int
 184 mono_mutex_lock (mono_mutex_t *mutex)
 185 {
 186         pthread_t id;
 187
 188         switch (mutex->type) {
 189         case MONO_MUTEX_NORMAL:
 190                 return pthread_mutex_lock (&mutex->mutex);
 191         case MONO_MUTEX_RECURSIVE:
 192                 id = pthread_self ();
 193                 if (pthread_mutex_lock (&mutex->mutex) != 0)
 194                         return EINVAL;
 195
 196                 while (1) {
 197                         if (pthread_equal (mutex->owner, MONO_THREAD_NONE)) {
 198                                 mutex->owner = id;
 199                                 mutex->depth = 1;
 200                                 break;
 201                         } else if (pthread_equal (mutex->owner, id)) {
 202                                 mutex->depth++;
 203                                 break;
 204                         } else {
 205                                 mutex->waiters++;
 206                                 if (pthread_cond_wait (&mutex->cond, &mutex->mutex) != 0)
 207                                         return EINVAL;
 208                                 mutex->waiters--;
 209                         }
 210                 }
 211
 212                 return pthread_mutex_unlock (&mutex->mutex);
 213         }
 214
 215         return EINVAL;
 216 }
 217
 218 int
 219 mono_mutex_trylock (mono_mutex_t *mutex)
 220 {
 221         pthread_t id;
 222
 223         switch (mutex->type) {
 224         case MONO_MUTEX_NORMAL:
 225                 return pthread_mutex_trylock (&mutex->mutex);
 226         case MONO_MUTEX_RECURSIVE:
 227                 id = pthread_self ();
 228
 229                 if (pthread_mutex_lock (&mutex->mutex) != 0)
 230                         return EINVAL;
 231
 232                 if (!pthread_equal (mutex->owner, MONO_THREAD_NONE) &&
 233                     !pthread_equal (mutex->owner, id)) {
 234                         pthread_mutex_unlock (&mutex->mutex);
 235                         return EBUSY;
 236                 }
 237
 238                 while (1) {
 239                         if (pthread_equal (mutex->owner, MONO_THREAD_NONE)) {
 240                                 mutex->owner = id;
 241                                 mutex->depth = 1;
 242                                 break;
 243                         } else {
 244                                 mutex->depth++;
 245                                 break;
 246                         }
 247                 }
 248
 249                 return pthread_mutex_unlock (&mutex->mutex);
 250         }
 251
 252         return EINVAL;
 253 }
 254
 255 int
 256 mono_mutex_timedlock (mono_mutex_t *mutex, const struct timespec *timeout)
 257 {
 258         pthread_t id;
 259
 260         switch (mutex->type) {
 261         case MONO_MUTEX_NORMAL:
 262                 return pthread_mutex_timedlock (&mutex->mutex, timeout);
 263         case MONO_MUTEX_RECURSIVE:
 264                 id = pthread_self ();
 265
 266                 if (pthread_mutex_timedlock (&mutex->mutex, timeout) != 0)
 267                         return ETIMEDOUT;
 268
 269                 while (1) {
 270                         if (pthread_equal (mutex->owner, MONO_THREAD_NONE)) {
 271                                 mutex->owner = id;
 272                                 mutex->depth = 1;
 273                                 break;
 274                         } else if (pthread_equal (mutex->owner, id)) {
 275                                 mutex->depth++;
 276                                 break;
 277                         } else {
 278                                 mutex->waiters++;
 279                                 if (pthread_cond_timedwait (&mutex->cond, &mutex->mutex, timeout) != 0)
 280                                         return ETIMEDOUT;
 281                                 mutex->waiters--;
 282                         }
 283                 }
 284
 285                 return pthread_mutex_unlock (&mutex->mutex);
 286         }
 287
 288         return EINVAL;
 289 }
 290
 291 int
 292 mono_mutex_unlock (mono_mutex_t *mutex)
 293 {
 294         int thr_ret;
 295
 296         switch (mutex->type) {
 297         case MONO_MUTEX_NORMAL:
 298                 return pthread_mutex_unlock (&mutex->mutex);
 299         case MONO_MUTEX_RECURSIVE:
 300                 if (pthread_mutex_lock (&mutex->mutex) != 0)
 301                         return EINVAL;
 302
 303                 if (pthread_equal (mutex->owner, pthread_self())) {
 304                         /* Not owned by this thread */
 305                         pthread_mutex_unlock (&mutex->mutex);
 306                         return EPERM;
 307                 }
 308
 309                 mutex->depth--;
 310                 if (mutex->depth == 0) {
 311                         mutex->owner = MONO_THREAD_NONE;
 312                         if (mutex->waiters > 0) {
 313                                 thr_ret = pthread_cond_signal (&mutex->cond);
 314                                 g_assert (thr_ret == 0);
 315                         }
 316                 }
 317
 318                 return pthread_mutex_unlock (&mutex->mutex);
 319         }
 320
 321         return EINVAL;
 322 }
 323
 324 int
 325 mono_mutex_destroy (mono_mutex_t *mutex)
 326 {
 327         int ret = 0;
 328         int thr_ret;
 329
 330         switch (mutex->type) {
 331         case MONO_MUTEX_NORMAL:
 332                 ret = pthread_mutex_destroy (&mutex->mutex);
 333                 break;
 334         case MONO_MUTEX_RECURSIVE:
 335                 if ((ret = pthread_mutex_destroy (&mutex->mutex)) == 0) {
 336                         thr_ret = pthread_cond_destroy (&mutex->cond);
 337                         g_assert (thr_ret == 0);
 338                 }
 339         }
 340
 341         return ret;
 342 }
 343
 344
 345 int
 346 mono_cond_wait (pthread_cond_t *cond, mono_mutex_t *mutex)
 347 {
 348         return pthread_cond_wait (cond, &mutex->mutex);
 349 }
 350
 351 int
 352 mono_cond_timedwait (pthread_cond_t *cond, mono_mutex_t *mutex, const struct timespec *timeout)
 353 {
 354         return pthread_cond_timedwait (cond, &mutex->mutex, timeout);
 355 }
 356
 357 #endif /* USE_MONO_MUTEX */