线程互斥

函数接口：

int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void *(*start_routine) (void *), void *arg);
int pthread_join(pthread_t thread, void **retval);

int pthread_mutex_lock(pthread_mutex_t *mutex);
int pthread_mutex_unlock(pthread_mutex_t *mutex);

pthread_mutex_t mutex;

mutex = PTHREAD_MUTEX_INITIALIZER;

pthread_t tids[2];

void *(*pthread_handlers[])(void*)