Pthread Mutex

기본적으로 process 간은 불가능 하지만 shared memory + pshared 설정이면 가능

pthread_mutex_t mutex;
pthread_mutexattr_t attr;

pthread_mutexattr_init(&attr);
pthread_mutexattr_setpshared(&attr, PTRHEAD_PROCESS_SHARED);

pthread_mutex_init(&mutex, &attr);

pthread_mutex_lock(&mutex);

/* critical section */

pthread_mutex_unlock(&mutex);