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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 2014-2015
      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
     18 Magick::MutexLock::MutexLock(void)
     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
     65 Magick::MutexLock::~MutexLock(void)
     66 {
     67 #if defined(MAGICKCORE_HAVE_PTHREAD)
     68   int
     69     sysError;
     70 
     71   if ((sysError=::pthread_mutex_destroy(&_mutex)) == 0)
     72     return;
     73   throwExceptionExplicit(MagickCore::OptionError,"mutex destruction failed",
     74     strerror(sysError));
     75 #endif
     76 #if defined(_MT) && defined(_VISUALC_)
     77   if (::CloseHandle(_mutex) != 0)
     78     return;
     79   throwExceptionExplicit(MagickCore::OptionError,"mutex destruction failed");
     80 #endif
     81 }
     82 
     83 // Lock mutex
     84 void Magick::MutexLock::lock(void)
     85 {
     86 #if defined(MAGICKCORE_HAVE_PTHREAD)
     87   int
     88     sysError;
     89 
     90   if ((sysError=::pthread_mutex_lock(&_mutex)) == 0)
     91     return;
     92   throwExceptionExplicit(MagickCore::OptionError,"mutex lock failed",
     93     strerror(sysError));
     94 #endif
     95 #if defined(_MT) && defined(_VISUALC_)
     96   if (WaitForSingleObject(_mutex,INFINITE) != WAIT_FAILED)
     97     return;
     98   throwExceptionExplicit(MagickCore::OptionError,"mutex lock failed");
     99 #endif
    100 }
    101 
    102 // Unlock mutex
    103 void Magick::MutexLock::unlock(void)
    104 {
    105 #if defined(MAGICKCORE_HAVE_PTHREAD)
    106   int
    107     sysError;
    108 
    109   if ((sysError=::pthread_mutex_unlock(&_mutex)) == 0)
    110     return;
    111   throwExceptionExplicit(MagickCore::OptionError,"mutex unlock failed",
    112     strerror(sysError));
    113 #endif
    114 #if defined(_MT) && defined(_VISUALC_)
    115   if (ReleaseSemaphore(_mutex,1,(LPLONG) NULL) == TRUE)
    116     return;
    117   throwExceptionExplicit(MagickCore::OptionError,"mutex unlock failed");
    118 #endif
    119 }
    120