Magick++ 6.9.13
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Thread.cpp
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
18Magick::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
60Magick::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
71void 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
88void 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}