MagickCore  7.0.10
mutex.h
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1 /*
2  Copyright 1999-2020 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. You may
6  obtain a copy of the License at
7 
8  https://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 methods to synchronize code within a translation unit.
17 */
18 #ifndef MAGICKCORE_MUTEX_H
19 #define MAGICKCORE_MUTEX_H
20 
21 #if defined(__cplusplus) || defined(c_plusplus)
22 extern "C" {
23 #endif
24 
25 /*
26  When included in a translation unit, the following code provides the
27  translation unit a means by which to synchronize multiple threads that might
28  try to enter the same critical section or to access a shared resource; it can
29  be included in multiple translation units, and thereby provide a separate,
30  independent means of synchronization to each such translation unit.
31 */
32 
33 #if defined(MAGICKCORE_OPENMP_SUPPORT)
34 static MagickBooleanType
35  translation_unit_initialized = MagickFalse;
36 
37 static omp_lock_t
38  translation_unit_mutex;
39 #elif defined(MAGICKCORE_THREAD_SUPPORT)
40 static pthread_mutex_t
41  translation_unit_mutex = PTHREAD_MUTEX_INITIALIZER;
42 #elif defined(MAGICKCORE_WINDOWS_SUPPORT)
43 static LONG
44  translation_unit_mutex = 0;
45 #endif
46 
47 static inline void DestroyMagickMutex(void)
48 {
49 #if defined(MAGICKCORE_OPENMP_SUPPORT)
50  omp_destroy_lock(&translation_unit_mutex);
51  translation_unit_initialized=MagickFalse;
52 #endif
53 }
54 
55 static inline void InitializeMagickMutex(void)
56 {
57 #if defined(MAGICKCORE_OPENMP_SUPPORT)
58  omp_init_lock(&translation_unit_mutex);
59  translation_unit_initialized=MagickTrue;
60 #endif
61 }
62 
63 static inline void LockMagickMutex(void)
64 {
65 #if defined(MAGICKCORE_OPENMP_SUPPORT)
66  if (translation_unit_initialized == MagickFalse)
68  omp_set_lock(&translation_unit_mutex);
69 #elif defined(MAGICKCORE_THREAD_SUPPORT)
70  {
71  int
72  status;
73 
74  status=pthread_mutex_lock(&translation_unit_mutex);
75  if (status != 0)
76  {
77  errno=status;
78  ThrowFatalException(ResourceLimitFatalError,"UnableToLockSemaphore");
79  }
80  }
81 #elif defined(MAGICKCORE_WINDOWS_SUPPORT)
82  while (InterlockedCompareExchange(&translation_unit_mutex,1L,0L) != 0)
83  Sleep(10);
84 #endif
85 }
86 
87 static inline void UnlockMagickMutex(void)
88 {
89 #if defined(MAGICKCORE_OPENMP_SUPPORT)
90  omp_unset_lock(&translation_unit_mutex);
91 #elif defined(MAGICKCORE_THREAD_SUPPORT)
92  {
93  int
94  status;
95 
96  status=pthread_mutex_unlock(&translation_unit_mutex);
97  if (status != 0)
98  {
99  errno=status;
100  ThrowFatalException(ResourceLimitFatalError,"UnableToUnlockSemaphore");
101  }
102  }
103 #elif defined(MAGICKCORE_WINDOWS_SUPPORT)
104  InterlockedExchange(&translation_unit_mutex,0L);
105 #endif
106 }
107 
108 #if defined(__cplusplus) || defined(c_plusplus)
109 }
110 #endif
111 
112 #endif
static void InitializeMagickMutex(void)
Definition: mutex.h:55
#define ThrowFatalException(severity, tag)
#define pthread_mutex_lock
Definition: vms.h:824
MagickBooleanType
Definition: magick-type.h:169
static void UnlockMagickMutex(void)
Definition: mutex.h:87
#define pthread_mutex_unlock
Definition: vms.h:826
static void LockMagickMutex(void)
Definition: mutex.h:63
static void DestroyMagickMutex(void)
Definition: mutex.h:47