Translations:Pthreads/8/en

The simplest and most common way to control the reading and writing of data shared among threads is the mutex, derived from the expression 'mutual exclusion'. In pthreads, a mutex is a kind of variable that may be "locked" or "owned" by only one thread at a time. The thread must then release or unlock the mutex once the global data has been read or modified. The code that lies between the call to lock a mutex and the call to unlock it will only be executed by a single thread at a time. To create a mutex in a pthreads program, we declare a global variable of type pthread_mutex_t which must be initialized before it is used by calling pthread_mutex_init. At the program's end we release the resources associated with the mutex by calling pthread_mutex_destroy.