src/libstrongswan/threading/mutex.c

   1 /*
   2  * Copyright (C) 2008-2009 Tobias Brunner
   3  * Copyright (C) 2008 Martin Willi
   4  * Hochschule fuer Technik Rapperswil
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2 of the License, or (at your
   9  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * for more details.
  15  */
  16
  17 #define _GNU_SOURCE
  18 #include <pthread.h>
  19 #include <stdint.h>
  20 #include <time.h>
  21 #include <errno.h>
  22
  23 #include <library.h>
  24 #include <debug.h>
  25
  26 #include "condvar.h"
  27 #include "mutex.h"
  28 #include "lock_profiler.h"
  29
  30 typedef struct private_mutex_t private_mutex_t;
  31 typedef struct private_r_mutex_t private_r_mutex_t;
  32 typedef struct private_condvar_t private_condvar_t;
  33
  34 /**
  35  * private data of mutex
  36  */
  37 struct private_mutex_t {
  38
  39         /**
  40          * public functions
  41          */
  42         mutex_t public;
  43
  44         /**
  45          * wrapped pthread mutex
  46          */
  47         pthread_mutex_t mutex;
  48
  49         /**
  50          * is this a recursiv emutex, implementing private_r_mutex_t?
  51          */
  52         bool recursive;
  53
  54         /**
  55          * profiling info, if enabled
  56          */
  57         lock_profile_t profile;
  58 };
  59
  60 /**
  61  * private data of mutex, extended by recursive locking information
  62  */
  63 struct private_r_mutex_t {
  64
  65         /**
  66          * Extends private_mutex_t
  67          */
  68         private_mutex_t generic;
  69
  70         /**
  71          * thread which currently owns mutex
  72          */
  73         pthread_t thread;
  74
  75         /**
  76          * times we have locked the lock, stored per thread
  77          */
  78         pthread_key_t times;
  79 };
  80
  81 /**
  82  * private data of condvar
  83  */
  84 struct private_condvar_t {
  85
  86         /**
  87          * public functions
  88          */
  89         condvar_t public;
  90
  91         /**
  92          * wrapped pthread condvar
  93          */
  94         pthread_cond_t condvar;
  95
  96 };
  97
  98
  99
 100 /**
 101  * Implementation of mutex_t.lock.
 102  */
 103 static void lock(private_mutex_t *this)
 104 {
 105         int err;
 106
 107         profiler_start(&this->profile);
 108         err = pthread_mutex_lock(&this->mutex);
 109         if (err)
 110         {
 111                 DBG1(DBG_LIB, "!!! MUTEX LOCK ERROR: %s !!!", strerror(err));
 112         }
 113         profiler_end(&this->profile);
 114 }
 115
 116 /**
 117  * Implementation of mutex_t.unlock.
 118  */
 119 static void unlock(private_mutex_t *this)
 120 {
 121         int err;
 122
 123         err = pthread_mutex_unlock(&this->mutex);
 124         if (err)
 125         {
 126                 DBG1(DBG_LIB, "!!! MUTEX UNLOCK ERROR: %s !!!", strerror(err));
 127         }
 128 }
 129
 130 /**
 131  * Implementation of mutex_t.lock.
 132  */
 133 static void lock_r(private_r_mutex_t *this)
 134 {
 135         pthread_t self = pthread_self();
 136
 137         if (this->thread == self)
 138         {
 139                 uintptr_t times;
 140
 141                 /* times++ */
 142                 times = (uintptr_t)pthread_getspecific(this->times);
 143                 pthread_setspecific(this->times, (void*)times + 1);
 144         }
 145         else
 146         {
 147                 lock(&this->generic);
 148                 this->thread = self;
 149                 /* times = 1 */
 150                 pthread_setspecific(this->times, (void*)1);
 151         }
 152 }
 153
 154 /**
 155  * Implementation of mutex_t.unlock.
 156  */
 157 static void unlock_r(private_r_mutex_t *this)
 158 {
 159         uintptr_t times;
 160
 161         /* times-- */
 162         times = (uintptr_t)pthread_getspecific(this->times);
 163         pthread_setspecific(this->times, (void*)--times);
 164
 165         if (times == 0)
 166         {
 167                 this->thread = 0;
 168                 unlock(&this->generic);
 169         }
 170 }
 171
 172 /**
 173  * Implementation of mutex_t.destroy
 174  */
 175 static void mutex_destroy(private_mutex_t *this)
 176 {
 177         profiler_cleanup(&this->profile);
 178         pthread_mutex_destroy(&this->mutex);
 179         free(this);
 180 }
 181
 182 /**
 183  * Implementation of mutex_t.destroy for recursive mutex'
 184  */
 185 static void mutex_destroy_r(private_r_mutex_t *this)
 186 {
 187         profiler_cleanup(&this->generic.profile);
 188         pthread_mutex_destroy(&this->generic.mutex);
 189         pthread_key_delete(this->times);
 190         free(this);
 191 }
 192
 193 /*
 194  * see header file
 195  */
 196 mutex_t *mutex_create(mutex_type_t type)
 197 {
 198         switch (type)
 199         {
 200                 case MUTEX_TYPE_RECURSIVE:
 201                 {
 202                         private_r_mutex_t *this = malloc_thing(private_r_mutex_t);
 203
 204                         this->generic.public.lock = (void(*)(mutex_t*))lock_r;
 205                         this->generic.public.unlock = (void(*)(mutex_t*))unlock_r;
 206                         this->generic.public.destroy = (void(*)(mutex_t*))mutex_destroy_r;
 207
 208                         pthread_mutex_init(&this->generic.mutex, NULL);
 209                         pthread_key_create(&this->times, NULL);
 210                         this->generic.recursive = TRUE;
 211                         profiler_init(&this->generic.profile);
 212                         this->thread = 0;
 213
 214                         return &this->generic.public;
 215                 }
 216                 case MUTEX_TYPE_DEFAULT:
 217                 default:
 218                 {
 219                         private_mutex_t *this = malloc_thing(private_mutex_t);
 220
 221                         this->public.lock = (void(*)(mutex_t*))lock;
 222                         this->public.unlock = (void(*)(mutex_t*))unlock;
 223                         this->public.destroy = (void(*)(mutex_t*))mutex_destroy;
 224
 225                         pthread_mutex_init(&this->mutex, NULL);
 226                         this->recursive = FALSE;
 227                         profiler_init(&this->profile);
 228
 229                         return &this->public;
 230                 }
 231         }
 232 }
 233
 234
 235
 236 /**
 237  * Implementation of condvar_t.wait.
 238  */
 239 static void _wait(private_condvar_t *this, private_mutex_t *mutex)
 240 {
 241         if (mutex->recursive)
 242         {
 243                 private_r_mutex_t* recursive = (private_r_mutex_t*)mutex;
 244
 245                 /* mutex owner gets cleared during condvar wait */
 246                 recursive->thread = 0;
 247                 pthread_cond_wait(&this->condvar, &mutex->mutex);
 248                 recursive->thread = pthread_self();
 249         }
 250         else
 251         {
 252                 pthread_cond_wait(&this->condvar, &mutex->mutex);
 253         }
 254 }
 255
 256 /* use the monotonic clock based version of this function if available */
 257 #ifdef HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC
 258 #define pthread_cond_timedwait pthread_cond_timedwait_monotonic
 259 #endif
 260
 261 /**
 262  * Implementation of condvar_t.timed_wait_abs.
 263  */
 264 static bool timed_wait_abs(private_condvar_t *this, private_mutex_t *mutex,
 265                                                    timeval_t time)
 266 {
 267         struct timespec ts;
 268         bool timed_out;
 269
 270         ts.tv_sec = time.tv_sec;
 271         ts.tv_nsec = time.tv_usec * 1000;
 272
 273         if (mutex->recursive)
 274         {
 275                 private_r_mutex_t* recursive = (private_r_mutex_t*)mutex;
 276
 277                 recursive->thread = 0;
 278                 timed_out = pthread_cond_timedwait(&this->condvar, &mutex->mutex,
 279                                                                                    &ts) == ETIMEDOUT;
 280                 recursive->thread = pthread_self();
 281         }
 282         else
 283         {
 284                 timed_out = pthread_cond_timedwait(&this->condvar, &mutex->mutex,
 285                                                                                    &ts) == ETIMEDOUT;
 286         }
 287         return timed_out;
 288 }
 289
 290 /**
 291  * Implementation of condvar_t.timed_wait.
 292  */
 293 static bool timed_wait(private_condvar_t *this, private_mutex_t *mutex,
 294                                            u_int timeout)
 295 {
 296         timeval_t tv;
 297         u_int s, ms;
 298
 299         time_monotonic(&tv);
 300
 301         s = timeout / 1000;
 302         ms = timeout % 1000;
 303
 304         tv.tv_sec += s;
 305         tv.tv_usec += ms * 1000;
 306
 307         if (tv.tv_usec > 1000000 /* 1s */)
 308         {
 309                 tv.tv_usec -= 1000000;
 310                 tv.tv_sec++;
 311         }
 312         return timed_wait_abs(this, mutex, tv);
 313 }
 314
 315 /**
 316  * Implementation of condvar_t.signal.
 317  */
 318 static void _signal(private_condvar_t *this)
 319 {
 320         pthread_cond_signal(&this->condvar);
 321 }
 322
 323 /**
 324  * Implementation of condvar_t.broadcast.
 325  */
 326 static void broadcast(private_condvar_t *this)
 327 {
 328         pthread_cond_broadcast(&this->condvar);
 329 }
 330
 331 /**
 332  * Implementation of condvar_t.destroy
 333  */
 334 static void condvar_destroy(private_condvar_t *this)
 335 {
 336         pthread_cond_destroy(&this->condvar);
 337         free(this);
 338 }
 339
 340 /*
 341  * see header file
 342  */
 343 condvar_t *condvar_create(condvar_type_t type)
 344 {
 345         switch (type)
 346         {
 347                 case CONDVAR_TYPE_DEFAULT:
 348                 default:
 349                 {
 350                         private_condvar_t *this = malloc_thing(private_condvar_t);
 351
 352                         this->public.wait = (void(*)(condvar_t*, mutex_t *mutex))_wait;
 353                         this->public.timed_wait = (bool(*)(condvar_t*, mutex_t *mutex, u_int timeout))timed_wait;
 354                         this->public.timed_wait_abs = (bool(*)(condvar_t*, mutex_t *mutex, timeval_t time))timed_wait_abs;
 355                         this->public.signal = (void(*)(condvar_t*))_signal;
 356                         this->public.broadcast = (void(*)(condvar_t*))broadcast;
 357                         this->public.destroy = (void(*)(condvar_t*))condvar_destroy;
 358
 359 #ifdef HAVE_PTHREAD_CONDATTR_INIT
 360                         {
 361                                 pthread_condattr_t condattr;
 362                                 pthread_condattr_init(&condattr);
 363 #ifdef HAVE_CONDATTR_CLOCK_MONOTONIC
 364                                 pthread_condattr_setclock(&condattr, CLOCK_MONOTONIC);
 365 #endif
 366                                 pthread_cond_init(&this->condvar, &condattr);
 367                                 pthread_condattr_destroy(&condattr);
 368                         }
 369 #endif
 370
 371                         return &this->public;
 372                 }
 373         }
 374 }
 375