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