27     sysError;  in MutexLock()  local
29   if ((sysError=::pthread_mutexattr_init(&attr)) == 0)  in MutexLock()
30     if ((sysError=::pthread_mutex_init(&_mutex,&attr)) == 0)  in MutexLock()
36     strerror(sysError));  in MutexLock()
69     sysError;  in ~MutexLock()  local
71   if ((sysError=::pthread_mutex_destroy(&_mutex)) == 0)  in ~MutexLock()
74     strerror(sysError));  in ~MutexLock()
88     sysError;  in lock()  local
90   if ((sysError=::pthread_mutex_lock(&_mutex)) == 0)  in lock()
93     strerror(sysError));  in lock()
107     sysError;  in unlock()  local
109   if ((sysError=::pthread_mutex_unlock(&_mutex)) == 0)  in unlock()
112     strerror(sysError));  in unlock()