MagickCore  6.8.5
semaphore-private.h
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1 /*
2  Copyright 1999-2013 ImageMagick Studio LLC, a non-profit organization
3  dedicated to making software imaging solutions freely available.
4 
5  You may not use this file except in compliance with the License.
6  obtain a copy of the License at
7 
8  http://www.imagemagick.org/script/license.php
9 
10  Unless required by applicable law or agreed to in writing, software
11  distributed under the License is distributed on an "AS IS" BASIS,
12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  See the License for the specific language governing permissions and
14  limitations under the License.
15 
16  MagickCore private methods to lock and unlock semaphores.
17 */
18 #ifndef _MAGICKCORE_SEMAPHORE_PRIVATE_H
19 #define _MAGICKCORE_SEMAPHORE_PRIVATE_H
20 
21 #if defined(__cplusplus) || defined(c_plusplus)
22 extern "C" {
23 #endif
24 
25 #if defined(MAGICKCORE_THREAD_SUPPORT)
26 static pthread_mutex_t
27  semaphore_mutex = PTHREAD_MUTEX_INITIALIZER;
28 #elif defined(MAGICKCORE_HAVE_WINTHREADS)
29 static LONG
30  semaphore_mutex = 0;
31 #else
32 static ssize_t
33  semaphore_mutex = 0;
34 #endif
35 
36 static inline void LockMagickMutex(void)
37 {
38 #if defined(MAGICKCORE_THREAD_SUPPORT)
39  {
40  int
41  status;
42 
43  status=pthread_mutex_lock(&semaphore_mutex);
44  if (status != 0)
45  {
46  errno=status;
47  ThrowFatalException(ResourceLimitFatalError,"UnableToLockSemaphore");
48  }
49  }
50 #elif defined(MAGICKCORE_HAVE_WINTHREADS)
51  while (InterlockedCompareExchange(&semaphore_mutex,1L,0L) != 0)
52  Sleep(10);
53 #endif
54 }
55 
56 static inline void UnlockMagickMutex(void)
57 {
58 #if defined(MAGICKCORE_THREAD_SUPPORT)
59  {
60  int
61  status;
62 
63  status=pthread_mutex_unlock(&semaphore_mutex);
64  if (status != 0)
65  {
66  errno=status;
67  ThrowFatalException(ResourceLimitFatalError,"UnableToUnlockSemaphore");
68  }
69  }
70 #elif defined(MAGICKCORE_HAVE_WINTHREADS)
71  InterlockedExchange(&semaphore_mutex,0L);
72 #endif
73 }
74 
75 #if defined(__cplusplus) || defined(c_plusplus)
76 }
77 #endif
78 
79 #endif