Magick++  7.0.8
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Thread.cpp
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1 // This may look like C code, but it is really -*- C++ -*-
2 //
3 // Copyright Bob Friesenhahn, 1999, 2000, 2001, 2002
4 // Copyright Dirk Lemstra 2014-2017
5 //
6 // Implementation of thread support
7 //
8 
9 #define MAGICKCORE_IMPLEMENTATION 1
10 #define MAGICK_PLUSPLUS_IMPLEMENTATION 1
11 
12 #include "Magick++/Thread.h"
13 #include "Magick++/Exception.h"
14 
15 #include <string.h>
16 
17 // Default constructor
19 #if defined(MAGICKCORE_HAVE_PTHREAD)
20  // POSIX threads
21  : _mutex()
22 {
23  ::pthread_mutexattr_t
24  attr;
25 
26  int
27  sysError;
28 
29  if ((sysError=::pthread_mutexattr_init(&attr)) == 0)
30  if ((sysError=::pthread_mutex_init(&_mutex,&attr)) == 0)
31  {
32  ::pthread_mutexattr_destroy(&attr);
33  return;
34  }
35  throwExceptionExplicit(MagickCore::OptionError,"mutex initialization failed",
36  strerror(sysError));
37 }
38 #else
39 #if defined(_VISUALC_) && defined(_MT)
40 // Win32 threads
41 {
42  SECURITY_ATTRIBUTES
43  security;
44 
45  /* Allow the semaphore to be inherited */
46  security.nLength=sizeof(security);
47  security.lpSecurityDescriptor=(LPVOID) NULL;
48  security.bInheritHandle=TRUE;
49 
50  /* Create the semaphore, with initial value signaled */
51  _mutex=::CreateSemaphore(&security,1,1,(LPCSTR) NULL);
52  if (_mutex != (HANDLE) NULL)
53  return;
54  throwExceptionExplicit(MagickCore::OptionError,
55  "mutex initialization failed");
56 }
57 #else
58 // Threads not supported
59 {
60 }
61 #endif
62 #endif
63 
64 // Destructor
66 {
67 #if defined(MAGICKCORE_HAVE_PTHREAD)
68  (void) ::pthread_mutex_destroy(&_mutex);
69 #endif
70 #if defined(_MT) && defined(_VISUALC_)
71  (void) ::CloseHandle(_mutex);
72 #endif
73 }
74 
75 // Lock mutex
77 {
78 #if defined(MAGICKCORE_HAVE_PTHREAD)
79  int
80  sysError;
81 
82  if ((sysError=::pthread_mutex_lock(&_mutex)) == 0)
83  return;
84  throwExceptionExplicit(MagickCore::OptionError,"mutex lock failed",
85  strerror(sysError));
86 #endif
87 #if defined(_MT) && defined(_VISUALC_)
88  if (WaitForSingleObject(_mutex,INFINITE) != WAIT_FAILED)
89  return;
90  throwExceptionExplicit(MagickCore::OptionError,"mutex lock failed");
91 #endif
92 }
93 
94 // Unlock mutex
96 {
97 #if defined(MAGICKCORE_HAVE_PTHREAD)
98  int
99  sysError;
100 
101  if ((sysError=::pthread_mutex_unlock(&_mutex)) == 0)
102  return;
103  throwExceptionExplicit(MagickCore::OptionError,"mutex unlock failed",
104  strerror(sysError));
105 #endif
106 #if defined(_MT) && defined(_VISUALC_)
107  if (ReleaseSemaphore(_mutex,1,(LPLONG) NULL) == TRUE)
108  return;
109  throwExceptionExplicit(MagickCore::OptionError,"mutex unlock failed");
110 #endif
111 }
~MutexLock(void)
Definition: Thread.cpp:65
void unlock(void)
Definition: Thread.cpp:95
void lock(void)
Definition: Thread.cpp:76
MagickPPExport void throwExceptionExplicit(const MagickCore::ExceptionType severity_, const char *reason_, const char *description_=(char *) NULL)
Definition: Exception.cpp:806