granicus.if.org Git - imagemagick/blob - MagickCore/semaphore.c

   1 /*
   2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   3 %                                                                             %
   4 %                                                                             %
   5 %                                                                             %
   6 %        SSSSS  EEEEE  M   M   AAA   PPPP   H   H   OOO   RRRR   EEEEE        %
   7 %        SS     E      MM MM  A   A  P   P  H   H  O   O  R   R  E            %
   8 %         SSS   EEE    M M M  AAAAA  PPPP   HHHHH  O   O  RRRR   EEE          %
   9 %           SS  E      M   M  A   A  P      H   H  O   O  R R    E            %
  10 %        SSSSS  EEEEE  M   M  A   A  P      H   H   OOO   R  R   EEEEE        %
  11 %                                                                             %
  12 %                                                                             %
  13 %                        MagickCore Semaphore Methods                         %
  14 %                                                                             %
  15 %                              Software Design                                %
  16 %                             William Radcliffe                               %
  17 %                                John Cristy                                  %
  18 %                                 June 2000                                   %
  19 %                                                                             %
  20 %                                                                             %
  21 %  Copyright 1999-2012 ImageMagick Studio LLC, a non-profit organization      %
  22 %  dedicated to making software imaging solutions freely available.           %
  23 %                                                                             %
  24 %  You may not use this file except in compliance with the License.  You may  %
  25 %  obtain a copy of the License at                                            %
  26 %                                                                             %
  27 %    http://www.imagemagick.org/script/license.php                            %
  28 %                                                                             %
  29 %  Unless required by applicable law or agreed to in writing, software        %
  30 %  distributed under the License is distributed on an "AS IS" BASIS,          %
  31 %  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
  32 %  See the License for the specific language governing permissions and        %
  33 %  limitations under the License.                                             %
  34 %                                                                             %
  35 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  36 %
  37 %
  38 %
  39 */
  40 \f
  41 /*
  42   Include declarations.
  43 */
  44 #include "MagickCore/studio.h"
  45 #include "MagickCore/exception.h"
  46 #include "MagickCore/exception-private.h"
  47 #include "MagickCore/memory_.h"
  48 #include "MagickCore/semaphore.h"
  49 #include "MagickCore/semaphore-private.h"
  50 #include "MagickCore/string_.h"
  51 #include "MagickCore/thread_.h"
  52 #include "MagickCore/thread-private.h"
  53 \f
  54 /*
  55   Struct declaractions.
  56 */
  57 struct SemaphoreInfo
  58 {
  59   MagickMutexType
  60     mutex;
  61
  62   MagickThreadType
  63     id;
  64
  65   ssize_t
  66     reference_count;
  67
  68   size_t
  69     signature;
  70 };
  71 \f
  72 /*
  73 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  74 %                                                                             %
  75 %                                                                             %
  76 %                                                                             %
  77 %   A c q u i r e S e m a p h o r e I n f o                                   %
  78 %                                                                             %
  79 %                                                                             %
  80 %                                                                             %
  81 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  82 %
  83 %  AcquireSemaphoreInfo() acquires a semaphore.
  84 %
  85 %  The format of the AcquireSemaphoreInfo method is:
  86 %
  87 %      void AcquireSemaphoreInfo(SemaphoreInfo **semaphore_info)
  88 %
  89 %  A description of each parameter follows:
  90 %
  91 %    o semaphore_info: Specifies a pointer to an SemaphoreInfo structure.
  92 %
  93 */
  94 MagickExport void AcquireSemaphoreInfo(SemaphoreInfo **semaphore_info)
  95 {
  96   assert(semaphore_info != (SemaphoreInfo **) NULL);
  97   if (*semaphore_info == (SemaphoreInfo *) NULL)
  98     {
  99       LockMagickMutex();
 100       if (*semaphore_info == (SemaphoreInfo *) NULL)
 101         *semaphore_info=AllocateSemaphoreInfo();
 102       UnlockMagickMutex();
 103     }
 104 }
 105 \f
 106 /*
 107 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 108 %                                                                             %
 109 %                                                                             %
 110 %                                                                             %
 111 %   A l l o c a t e S e m a p h o r e I n f o                                 %
 112 %                                                                             %
 113 %                                                                             %
 114 %                                                                             %
 115 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 116 %
 117 %  AllocateSemaphoreInfo() initializes the SemaphoreInfo structure.
 118 %
 119 %  The format of the AllocateSemaphoreInfo method is:
 120 %
 121 %      SemaphoreInfo *AllocateSemaphoreInfo(void)
 122 %
 123 */
 124 MagickExport SemaphoreInfo *AllocateSemaphoreInfo(void)
 125 {
 126   SemaphoreInfo
 127     *semaphore_info;
 128
 129   /*
 130     Allocate semaphore.
 131   */
 132   semaphore_info=(SemaphoreInfo *) malloc(sizeof(SemaphoreInfo));
 133   if (semaphore_info == (SemaphoreInfo *) NULL)
 134     ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
 135   (void) ResetMagickMemory(semaphore_info,0,sizeof(SemaphoreInfo));
 136   /*
 137     Initialize the semaphore.
 138   */
 139 #if defined(MAGICKCORE_THREAD_SUPPORT)
 140   {
 141     int
 142       status;
 143
 144     pthread_mutexattr_t
 145       mutex_info;
 146
 147     status=pthread_mutexattr_init(&mutex_info);
 148     if (status != 0)
 149       {
 150         errno=status;
 151         ThrowFatalException(ResourceLimitFatalError,
 152           "UnableToInitializeSemaphore");
 153       }
 154 #if defined(MAGICKCORE_DEBUG)
 155 #if defined(PTHREAD_MUTEX_ERRORCHECK)
 156     status=pthread_mutex_settype(&mutex_info,PTHREAD_MUTEX_ERRORCHECK);
 157     if (status != 0)
 158       {
 159         errno=status;
 160         ThrowFatalException(ResourceLimitFatalError,
 161           "UnableToInitializeSemaphore");
 162       }
 163 #endif
 164 #endif
 165     status=pthread_mutex_init(&semaphore_info->mutex,&mutex_info);
 166     if (status != 0)
 167       {
 168         errno=status;
 169         ThrowFatalException(ResourceLimitFatalError,
 170           "UnableToInitializeSemaphore");
 171       }
 172     status=pthread_mutexattr_destroy(&mutex_info);
 173     if (status != 0)
 174       {
 175         errno=status;
 176         ThrowFatalException(ResourceLimitFatalError,
 177           "UnableToInitializeSemaphore");
 178       }
 179   }
 180 #elif defined(MAGICKCORE_HAVE_WINTHREADS)
 181   {
 182     int
 183       status;
 184
 185     status=InitializeCriticalSectionAndSpinCount(&semaphore_info->mutex,0x0400);
 186     if (status == 0)
 187       {
 188         errno=status;
 189         ThrowFatalException(ResourceLimitFatalError,
 190           "UnableToInitializeSemaphore");
 191        }
 192   }
 193 #endif
 194   semaphore_info->id=GetMagickThreadId();
 195   semaphore_info->reference_count=0;
 196   semaphore_info->signature=MagickSignature;
 197   return(semaphore_info);
 198 }
 199 \f
 200 /*
 201 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 202 %                                                                             %
 203 %                                                                             %
 204 %                                                                             %
 205 %   D e s t r o y S e m a p h o r e I n f o                                   %
 206 %                                                                             %
 207 %                                                                             %
 208 %                                                                             %
 209 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 210 %
 211 %  DestroySemaphoreInfo() destroys a semaphore.
 212 %
 213 %  The format of the DestroySemaphoreInfo method is:
 214 %
 215 %      void DestroySemaphoreInfo(SemaphoreInfo **semaphore_info)
 216 %
 217 %  A description of each parameter follows:
 218 %
 219 %    o semaphore_info: Specifies a pointer to an SemaphoreInfo structure.
 220 %
 221 */
 222 MagickExport void DestroySemaphoreInfo(SemaphoreInfo **semaphore_info)
 223 {
 224   assert(semaphore_info != (SemaphoreInfo **) NULL);
 225   assert((*semaphore_info) != (SemaphoreInfo *) NULL);
 226   assert((*semaphore_info)->signature == MagickSignature);
 227   LockMagickMutex();
 228 #if defined(MAGICKCORE_THREAD_SUPPORT)
 229   {
 230     int
 231       status;
 232
 233     status=pthread_mutex_destroy(&(*semaphore_info)->mutex);
 234     if (status != 0)
 235       {
 236         errno=status;
 237         ThrowFatalException(ResourceLimitFatalError,"UnableToDestroySemaphore");
 238       }
 239   }
 240 #elif defined(MAGICKCORE_HAVE_WINTHREADS)
 241   DeleteCriticalSection(&(*semaphore_info)->mutex);
 242 #endif
 243   (*semaphore_info)->signature=(~MagickSignature);
 244   free(*semaphore_info);
 245   *semaphore_info=(SemaphoreInfo *) NULL;
 246   UnlockMagickMutex();
 247 }
 248 \f
 249 /*
 250 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 251 %                                                                             %
 252 %                                                                             %
 253 %                                                                             %
 254 %   L o c k S e m a p h o r e I n f o                                         %
 255 %                                                                             %
 256 %                                                                             %
 257 %                                                                             %
 258 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 259 %
 260 %  LockSemaphoreInfo() locks a semaphore.
 261 %
 262 %  The format of the LockSemaphoreInfo method is:
 263 %
 264 %      void LockSemaphoreInfo(SemaphoreInfo *semaphore_info)
 265 %
 266 %  A description of each parameter follows:
 267 %
 268 %    o semaphore_info: Specifies a pointer to an SemaphoreInfo structure.
 269 %
 270 */
 271 MagickExport void LockSemaphoreInfo(SemaphoreInfo *semaphore_info)
 272 {
 273   assert(semaphore_info != (SemaphoreInfo *) NULL);
 274   assert(semaphore_info->signature == MagickSignature);
 275 #if defined(MAGICKCORE_THREAD_SUPPORT)
 276   {
 277     int
 278       status;
 279
 280     status=pthread_mutex_lock(&semaphore_info->mutex);
 281     if (status != 0)
 282       {
 283         errno=status;
 284         ThrowFatalException(ResourceLimitFatalError,"UnableToLockSemaphore");
 285       }
 286   }
 287 #elif defined(MAGICKCORE_HAVE_WINTHREADS)
 288   EnterCriticalSection(&semaphore_info->mutex);
 289 #endif
 290 #if defined(MAGICKCORE_DEBUG)
 291   if ((semaphore_info->reference_count > 0) &&
 292       (IsMagickThreadEqual(semaphore_info->id) != MagickFalse))
 293     {
 294       (void) FormatLocaleFile(stderr,"Warning: unexpected recursive lock!\n");
 295       (void) fflush(stderr);
 296     }
 297 #endif
 298   semaphore_info->id=GetMagickThreadId();
 299   semaphore_info->reference_count++;
 300 }
 301 \f
 302 /*
 303 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 304 %                                                                             %
 305 %                                                                             %
 306 %                                                                             %
 307 %   R e l i n g u i s h S e m a p h o r e I n f o                             %
 308 %                                                                             %
 309 %                                                                             %
 310 %                                                                             %
 311 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 312 %
 313 %  RelinquishSemaphoreInfo() relinquishes a semaphore.
 314 %
 315 %  The format of the RelinquishSemaphoreInfo method is:
 316 %
 317 %      RelinquishSemaphoreInfo(SemaphoreInfo *semaphore_info)
 318 %
 319 %  A description of each parameter follows:
 320 %
 321 %    o semaphore_info: Specifies a pointer to an SemaphoreInfo structure.
 322 %
 323 */
 324 MagickExport void RelinquishSemaphoreInfo(SemaphoreInfo *semaphore_info)
 325 {
 326   assert(semaphore_info != (SemaphoreInfo *) NULL);
 327   assert(semaphore_info->signature == MagickSignature);
 328   UnlockSemaphoreInfo(semaphore_info);
 329 }
 330 \f
 331 /*
 332 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 333 %                                                                             %
 334 %                                                                             %
 335 %                                                                             %
 336 %   S e m a p h o r e C o m p o n e n t G e n e s i s                         %
 337 %                                                                             %
 338 %                                                                             %
 339 %                                                                             %
 340 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 341 %
 342 %  SemaphoreComponentGenesis() instantiates the semaphore environment.
 343 %
 344 %  The format of the SemaphoreComponentGenesis method is:
 345 %
 346 %      MagickBooleanType SemaphoreComponentGenesis(void)
 347 %
 348 */
 349 MagickPrivate MagickBooleanType SemaphoreComponentGenesis(void)
 350 {
 351   LockMagickMutex();
 352   UnlockMagickMutex();
 353   return(MagickTrue);
 354 }
 355 \f
 356 /*
 357 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 358 %                                                                             %
 359 %                                                                             %
 360 %                                                                             %
 361 %   S e m a p h o r e C o m p o n e n t T e r m i n u s                       %
 362 %                                                                             %
 363 %                                                                             %
 364 %                                                                             %
 365 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 366 %
 367 %  SemaphoreComponentTerminus() destroys the semaphore component.
 368 %
 369 %  The format of the SemaphoreComponentTerminus method is:
 370 %
 371 %      SemaphoreComponentTerminus(void)
 372 %
 373 */
 374 MagickPrivate void SemaphoreComponentTerminus(void)
 375 {
 376 }
 377 \f
 378 /*
 379 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 380 %                                                                             %
 381 %                                                                             %
 382 %                                                                             %
 383 %   U n l o c k S e m a p h o r e I n f o                                     %
 384 %                                                                             %
 385 %                                                                             %
 386 %                                                                             %
 387 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 388 %
 389 %  UnlockSemaphoreInfo() unlocks a semaphore.
 390 %
 391 %  The format of the UnlockSemaphoreInfo method is:
 392 %
 393 %      void UnlockSemaphoreInfo(SemaphoreInfo *semaphore_info)
 394 %
 395 %  A description of each parameter follows:
 396 %
 397 %    o semaphore_info: Specifies a pointer to an SemaphoreInfo structure.
 398 %
 399 */
 400 MagickExport void UnlockSemaphoreInfo(SemaphoreInfo *semaphore_info)
 401 {
 402   assert(semaphore_info != (SemaphoreInfo *) NULL);
 403   assert(semaphore_info->signature == MagickSignature);
 404 #if defined(MAGICKCORE_DEBUG)
 405   assert(IsMagickThreadEqual(semaphore_info->id) != MagickFalse);
 406   if (semaphore_info->reference_count == 0)
 407     {
 408       (void) FormatLocaleFile(stderr,
 409         "Warning: semaphore lock already unlocked!\n");
 410       (void) fflush(stderr);
 411       return;
 412     }
 413   semaphore_info->reference_count--;
 414 #endif
 415 #if defined(MAGICKCORE_THREAD_SUPPORT)
 416   {
 417     int
 418       status;
 419
 420     status=pthread_mutex_unlock(&semaphore_info->mutex);
 421     if (status != 0)
 422       {
 423         errno=status;
 424         ThrowFatalException(ResourceLimitFatalError,"UnableToUnlockSemaphore");
 425       }
 426   }
 427 #elif defined(MAGICKCORE_HAVE_WINTHREADS)
 428   LeaveCriticalSection(&semaphore_info->mutex);
 429 #endif
 430 }