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 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
MutexLock(void)18 Magick::MutexLock::MutexLock(void)
19 #if defined(MAGICKCORE_HAVE_PTHREAD)
20 // POSIX threads
21 : _mutex()
22 {
23 ::pthread_mutexattr_t attr;
24 int sysError;
25 if ( (sysError = ::pthread_mutexattr_init( &attr )) == 0 )
26 if ( (sysError = ::pthread_mutex_init( &_mutex, &attr )) == 0 )
27 {
28 ::pthread_mutexattr_destroy( &attr );
29 return;
30 }
31 throwExceptionExplicit( OptionError, "mutex initialization failed",
32 strerror(sysError) );
33 }
34 #else
35 #if defined(_VISUALC_) && defined(_MT)
36 // Win32 threads
37 : _mutex()
38 {
39 SECURITY_ATTRIBUTES security;
40
41 /* Allow the semaphore to be inherited */
42 security.nLength = sizeof(security);
43 security.lpSecurityDescriptor = NULL;
44 security.bInheritHandle = TRUE;
45
46 /* Create the semaphore, with initial value signaled */
47 _mutex.id = ::CreateSemaphore(&security, 1, MAXSEMLEN, NULL);
48 if ( _mutex.id != NULL )
49 return;
50 throwExceptionExplicit( OptionError, "mutex initialization failed" );
51 }
52 #else
53 // Threads not supported
54 {
55 }
56 #endif
57 #endif
58
59 // Destructor
~MutexLock(void)60 Magick::MutexLock::~MutexLock(void)
61 {
62 #if defined(MAGICKCORE_HAVE_PTHREAD)
63 (void) ::pthread_mutex_destroy(&_mutex);
64 #endif
65 #if defined(_MT) && defined(_VISUALC_)
66 (void) ::CloseHandle(_mutex.id);
67 #endif
68 }
69
70 // Lock mutex
lock(void)71 void Magick::MutexLock::lock(void)
72 {
73 #if defined(MAGICKCORE_HAVE_PTHREAD)
74 int sysError;
75 if ( (sysError = ::pthread_mutex_lock( &_mutex )) == 0)
76 return;
77 throwExceptionExplicit( OptionError, "mutex lock failed",
78 strerror(sysError));
79 #endif
80 #if defined(_MT) && defined(_VISUALC_)
81 if (WaitForSingleObject(_mutex.id,INFINITE) != WAIT_FAILED)
82 return;
83 throwExceptionExplicit( OptionError, "mutex lock failed" );
84 #endif
85 }
86
87 // Unlock mutex
unlock(void)88 void Magick::MutexLock::unlock(void)
89 {
90 #if defined(MAGICKCORE_HAVE_PTHREAD)
91 int sysError;
92 if ( (sysError = ::pthread_mutex_unlock( &_mutex )) == 0)
93 return;
94 throwExceptionExplicit( OptionError, "mutex unlock failed",
95 strerror(sysError) );
96 #endif
97 #if defined(_MT) && defined(_VISUALC_)
98 if ( ReleaseSemaphore(_mutex.id, 1, NULL) == TRUE )
99 return;
100 throwExceptionExplicit( OptionError, "mutex unlock failed" );
101 #endif
102 }
103