线程——互斥锁

#include <stdio.h>
#include <pthread.h>

pthread_mutex_t mutex;   // 互斥锁
int ticket = 100;        // 票

void *sellticket(void *v)
{
	long num = (long)v;   // 窗口号
	
	srand((unsigned int)time(NULL));
	while (1)
	{
		usleep(100000*(rand()%10+1));
		
		pthread_mutex_lock(&mutex);          // 上锁
	
		if (0 == ticket)
		{
			printf ("票卖完了\n");
			pthread_mutex_unlock(&mutex);    // 解锁
			break;
		}
		printf ("%ld 窗口卖了一张票，座位号：%d\n", num, ticket);
		ticket -= 1;
	
		pthread_mutex_unlock(&mutex);        // 解锁
	}
}


int main(int argc, char **argv)
{
	long i;
	pthread_t thread[4];
	for (i = 0; i < 4; i++)
	{
		pthread_create(&thread[i], NULL, sellticket, (void*)(i+1));
	}
	pthread_mutex_init(&mutex, NULL);
	
	
	pthread_join(thread[0], NULL);
	pthread_join(thread[1], NULL);
	pthread_join(thread[2], NULL);
	pthread_join(thread[3], NULL);

	
	pthread_mutex_destroy(&mutex);
	return 0;
}