Pthread에서 Condition Variable 및 mutex 질문입니다

#include <pthread.h>
#include <time.h>
#include <stdio.h>
 
#define LOG printf("LOG >> line : %d\n", __LINE__)
 
typedef struct aa {
	pthread_mutex_t mutex;
	pthread_cond_t cond;
	int value;
} my_struct_t;
 
my_struct_t data = { PTHREAD_MUTEX_INITIALIZER, PTHREAD_COND_INITIALIZER, 0};
 
int hib = 1;
 
void * wait_thread (void *arg){
	int status;
	sleep(hib);
 
	status = pthread_mutex_lock(&data.mutex); /////////// 1번.
 
	data.value = 1;
 
	status = pthread_cond_signal (&data.cond);
 
	status = pthread_mutex_unlock(&data.mutex);
 
	return NULL;
}
 
int main (int argc, char *argv[]){
	int status;
	pthread_t wait_thread_id;
	struct timespec timeout;
 
	status = pthread_create (&wait_thread_id, NULL, wait_thread, NULL);
 
	pthread_yield();
	timeout.tv_sec = time(NULL) + 2;
	timeout.tv_nsec = 0;
 
	status = pthread_mutex_lock(&data.mutex); ////////// 2번.
 
	while (data.value == 0){
 
		status = pthread_cond_timedwait( &data.cond, &data.mutex, &timeout); //////// 3번.
 
		if (status == 110){ /////////////////////////// 4번
			printf("Condition wait timed out\n");
			break;
		}
	}
 
	if (data.value != 0)
		printf("condition was signaled\n");
 
	status = pthread_mutex_unlock(&data.mutex);
 
 
	return 0;
 
}