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 1999-2011 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     status=pthread_mutex_init(&semaphore_info->mutex,&mutex_info);
 155     if (status != 0)
 156       {
 157         errno=status;
 158         ThrowFatalException(ResourceLimitFatalError,
 159           "UnableToInitializeSemaphore");
 160       }
 161     status=pthread_mutexattr_destroy(&mutex_info);
 162     if (status != 0)
 163       {
 164         errno=status;
 165         ThrowFatalException(ResourceLimitFatalError,
 166           "UnableToInitializeSemaphore");
 167       }
 168   }
 169 #elif defined(MAGICKCORE_HAVE_WINTHREADS)
 170   {
 171     int
 172       status;
 173
 174     status=InitializeCriticalSectionAndSpinCount(&semaphore_info->mutex,0x0400);
 175     if (status == 0)
 176       {
 177         errno=status;
 178         ThrowFatalException(ResourceLimitFatalError,
 179           "UnableToInitializeSemaphore");
 180        }
 181   }
 182 #endif
 183   semaphore_info->id=GetMagickThreadId();
 184   semaphore_info->reference_count=0;
 185   semaphore_info->signature=MagickSignature;
 186   return(semaphore_info);
 187 }
 188 \f
 189 /*
 190 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 191 %                                                                             %
 192 %                                                                             %
 193 %                                                                             %
 194 %   D e s t r o y S e m a p h o r e I n f o                                   %
 195 %                                                                             %
 196 %                                                                             %
 197 %                                                                             %
 198 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 199 %
 200 %  DestroySemaphoreInfo() destroys a semaphore.
 201 %
 202 %  The format of the DestroySemaphoreInfo method is:
 203 %
 204 %      void DestroySemaphoreInfo(SemaphoreInfo **semaphore_info)
 205 %
 206 %  A description of each parameter follows:
 207 %
 208 %    o semaphore_info: Specifies a pointer to an SemaphoreInfo structure.
 209 %
 210 */
 211 MagickExport void DestroySemaphoreInfo(SemaphoreInfo **semaphore_info)
 212 {
 213   assert(semaphore_info != (SemaphoreInfo **) NULL);
 214   assert((*semaphore_info) != (SemaphoreInfo *) NULL);
 215   assert((*semaphore_info)->signature == MagickSignature);
 216   LockMagickMutex();
 217 #if defined(MAGICKCORE_THREAD_SUPPORT)
 218   {
 219     int
 220       status;
 221
 222     status=pthread_mutex_destroy(&(*semaphore_info)->mutex);
 223     if (status != 0)
 224       {
 225         errno=status;
 226         ThrowFatalException(ResourceLimitFatalError,"UnableToDestroySemaphore");
 227       }
 228   }
 229 #elif defined(MAGICKCORE_HAVE_WINTHREADS)
 230   DeleteCriticalSection(&(*semaphore_info)->mutex);
 231 #endif
 232   (*semaphore_info)->signature=(~MagickSignature);
 233   free(*semaphore_info);
 234   *semaphore_info=(SemaphoreInfo *) NULL;
 235   UnlockMagickMutex();
 236 }
 237 \f
 238 /*
 239 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 240 %                                                                             %
 241 %                                                                             %
 242 %                                                                             %
 243 %   L o c k S e m a p h o r e I n f o                                         %
 244 %                                                                             %
 245 %                                                                             %
 246 %                                                                             %
 247 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 248 %
 249 %  LockSemaphoreInfo() locks a semaphore.
 250 %
 251 %  The format of the LockSemaphoreInfo method is:
 252 %
 253 %      void LockSemaphoreInfo(SemaphoreInfo *semaphore_info)
 254 %
 255 %  A description of each parameter follows:
 256 %
 257 %    o semaphore_info: Specifies a pointer to an SemaphoreInfo structure.
 258 %
 259 */
 260 MagickExport void LockSemaphoreInfo(SemaphoreInfo *semaphore_info)
 261 {
 262   assert(semaphore_info != (SemaphoreInfo *) NULL);
 263   assert(semaphore_info->signature == MagickSignature);
 264 #if defined(MAGICKCORE_THREAD_SUPPORT)
 265   {
 266     int
 267       status;
 268
 269     status=pthread_mutex_lock(&semaphore_info->mutex);
 270     if (status != 0)
 271       {
 272         errno=status;
 273         ThrowFatalException(ResourceLimitFatalError,"UnableToLockSemaphore");
 274       }
 275   }
 276 #elif defined(MAGICKCORE_HAVE_WINTHREADS)
 277   EnterCriticalSection(&semaphore_info->mutex);
 278 #endif
 279 #if defined(MAGICKCORE_DEBUG)
 280   if ((semaphore_info->reference_count > 0) &&
 281       (IsMagickThreadEqual(semaphore_info->id) != MagickFalse))
 282     {
 283       (void) FormatLocaleFile(stderr,"Warning: unexpected recursive lock!\n");
 284       (void) fflush(stderr);
 285     }
 286 #endif
 287   semaphore_info->id=GetMagickThreadId();
 288   semaphore_info->reference_count++;
 289 }
 290 \f
 291 /*
 292 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 293 %                                                                             %
 294 %                                                                             %
 295 %                                                                             %
 296 %   R e l i n g u i s h S e m a p h o r e I n f o                             %
 297 %                                                                             %
 298 %                                                                             %
 299 %                                                                             %
 300 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 301 %
 302 %  RelinquishSemaphoreInfo() relinquishes a semaphore.
 303 %
 304 %  The format of the RelinquishSemaphoreInfo method is:
 305 %
 306 %      RelinquishSemaphoreInfo(SemaphoreInfo *semaphore_info)
 307 %
 308 %  A description of each parameter follows:
 309 %
 310 %    o semaphore_info: Specifies a pointer to an SemaphoreInfo structure.
 311 %
 312 */
 313 MagickExport void RelinquishSemaphoreInfo(SemaphoreInfo *semaphore_info)
 314 {
 315   assert(semaphore_info != (SemaphoreInfo *) NULL);
 316   assert(semaphore_info->signature == MagickSignature);
 317   UnlockSemaphoreInfo(semaphore_info);
 318 }
 319 \f
 320 /*
 321 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 322 %                                                                             %
 323 %                                                                             %
 324 %                                                                             %
 325 %   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                         %
 326 %                                                                             %
 327 %                                                                             %
 328 %                                                                             %
 329 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 330 %
 331 %  SemaphoreComponentGenesis() instantiates the semaphore environment.
 332 %
 333 %  The format of the SemaphoreComponentGenesis method is:
 334 %
 335 %      MagickBooleanType SemaphoreComponentGenesis(void)
 336 %
 337 */
 338 MagickExport MagickBooleanType SemaphoreComponentGenesis(void)
 339 {
 340   LockMagickMutex();
 341   UnlockMagickMutex();
 342   return(MagickTrue);
 343 }
 344 \f
 345 /*
 346 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 347 %                                                                             %
 348 %                                                                             %
 349 %                                                                             %
 350 %   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                       %
 351 %                                                                             %
 352 %                                                                             %
 353 %                                                                             %
 354 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 355 %
 356 %  SemaphoreComponentTerminus() destroys the semaphore component.
 357 %
 358 %  The format of the SemaphoreComponentTerminus method is:
 359 %
 360 %      SemaphoreComponentTerminus(void)
 361 %
 362 */
 363 MagickExport void SemaphoreComponentTerminus(void)
 364 {
 365 }
 366 \f
 367 /*
 368 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 369 %                                                                             %
 370 %                                                                             %
 371 %                                                                             %
 372 %   U n l o c k S e m a p h o r e I n f o                                     %
 373 %                                                                             %
 374 %                                                                             %
 375 %                                                                             %
 376 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 377 %
 378 %  UnlockSemaphoreInfo() unlocks a semaphore.
 379 %
 380 %  The format of the UnlockSemaphoreInfo method is:
 381 %
 382 %      void UnlockSemaphoreInfo(SemaphoreInfo *semaphore_info)
 383 %
 384 %  A description of each parameter follows:
 385 %
 386 %    o semaphore_info: Specifies a pointer to an SemaphoreInfo structure.
 387 %
 388 */
 389 MagickExport void UnlockSemaphoreInfo(SemaphoreInfo *semaphore_info)
 390 {
 391   assert(semaphore_info != (SemaphoreInfo *) NULL);
 392   assert(semaphore_info->signature == MagickSignature);
 393 #if defined(MAGICKCORE_DEBUG)
 394   assert(IsMagickThreadEqual(semaphore_info->id) != MagickFalse);
 395   if (semaphore_info->reference_count == 0)
 396     {
 397       (void) FormatLocaleFile(stderr,
 398         "Warning: semaphore lock already unlocked!\n");
 399       (void) fflush(stderr);
 400       return;
 401     }
 402   semaphore_info->reference_count--;
 403 #endif
 404 #if defined(MAGICKCORE_THREAD_SUPPORT)
 405   {
 406     int
 407       status;
 408
 409     status=pthread_mutex_unlock(&semaphore_info->mutex);
 410     if (status != 0)
 411       {
 412         errno=status;
 413         ThrowFatalException(ResourceLimitFatalError,"UnableToUnlockSemaphore");
 414       }
 415   }
 416 #elif defined(MAGICKCORE_HAVE_WINTHREADS)
 417   LeaveCriticalSection(&semaphore_info->mutex);
 418 #endif
 419 }