编写多进程程序,主线程中开启两个线程,一个线程打印十个偶数随机数,一个线程打印十个奇数随机数
#include <unistd.h>
#include <stdlib.h>
#include <pthread.h>
#include <stdio.h>
int g_num = 1;
pthread_mutex_t mutex;
pthread_cond_t cond1,cond2;
void* thread1(void* arg)
{
int flag1=0;
while(1)
{
flag1++;
pthread_mutex_lock(&mutex);
srand((unsigned int)time(NULL));
if((g_num=rand()*2+1)>0)
{
printf("%d奇数随机数为:%d\n",flag1,g_num);
}
else{
printf("%d奇数随机数为:%d\n",flag1,-g_num);
}
pthread_cond_signal(&cond2);
pthread_cond_wait(&cond1,&mutex);
pthread_mutex_unlock(&mutex);
sleep(1);
if (flag1==10)
{
break;
}
}
return NULL;
}
void* thread2(void* arg)
{
int flag2=0;
while(1)
{
flag2++;
//这个sleep(1)加在前面是因为开启线程时有可能是线程2先打印,
//导致变成thread2输出奇数,threa1输出偶数。为了避免这种情况,可以在延迟下线程2的打印。
sleep(1);
srand((unsigned int)time(NULL));
if((g_num=rand()*2)>0)
{
printf("%d偶数随机数为:%d\n", flag2,g_num);
}
else{
printf("%d偶数随机数为:%d\n",flag2,-g_num);
}
pthread_mutex_lock(&mutex);
pthread_cond_signal(&cond1);
pthread_cond_wait(&cond2,&mutex);
pthread_mutex_unlock(&mutex);
if (flag2==10)
{
break;
}
}
return NULL;
}
int main()
{
pthread_t p1,p2;
pthread_mutex_init(&mutex,NULL);
pthread_cond_init(&cond1,NULL);
pthread_cond_init(&cond2,NULL);
pthread_create(&p1,NULL,thread1,NULL);
pthread_create(&p2,NULL,thread2,NULL);
pthread_join(p1,NULL);
pthread_join(p2,NULL);
pthread_mutex_destroy(&mutex);
pthread_cond_destroy(&cond1);
pthread_cond_destroy(&cond2);
return 0;
}