使用互斥锁实现字符串的逆置

#include 
#include 
#include 
#include 
#include 
#include 

typedef void *(*pthread_func_t) (void *);
pthread_mutex_t mutex;
char buf[] = "hello world";

pthread_mutex_t mutex;
static int g_count = 0; 
void *read_string(void *arg)
{
	//sleep(1);
	while(1){
		pthread_mutex_lock(&mutex);
		printf("strings:%s\n",(char *)arg);
		//while(1);
		pthread_mutex_unlock(&mutex);
		printf("---------start reverse---%d---\n", g_count++);
		sleep(1);
        if(g_count == 5)
            break;
	}
	pthread_exit("read_ok");
}

void *reverse_string(void *arg)
{ 
	int i ;
	int length = strlen((char *)arg);
	usleep(100);

	while(1)
    {
		pthread_mutex_lock(&mutex);
		for(i = 0 ; i < length/2 ; i++)
        {
			((char *)arg)[i] ^= ((char *)arg)[length - i - 1];
			((char *)arg)[length - i - 1] ^= ((char *)arg)[i];
			((char *)arg)[i] ^= ((char *)arg)[length - i - 1];

            usleep(100);	
		}
		pthread_mutex_unlock(&mutex);

        if(g_count == 5)
            break;
	}
	pthread_exit("reverse buff is ok!");
}

int main(int argc, char const *argv[])
{
	int i , ret ;
	pthread_t tid_arr[2];
	void *ret_arr[2];
	pthread_func_t func[2] = {read_string, reverse_string};

	pthread_mutex_init(&mutex, NULL);

	for(i = 0; i < 2 ; i++)
    {
		ret = pthread_create(&tid_arr[i], NULL, func[i], (void *)buf);
		if(ret < 0)
        {
			perror("pthread_create");
			return ret;
		}
	}
	
	for(i = 0; i < 2 ; i++)
    {
		ret = pthread_join(tid_arr[i], &ret_arr[i]);
		if(ret < 0)
        {
			perror("pthread_join");
			return ret;
		}
        
		printf("pthread %d : %s\n", i, (char *)ret_arr[i]);
	}

	pthread_mutex_destroy(&mutex);

	return 0;
}

测试结果