POSIX线程

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

int g_flag=0;

void *thread1()
{
    printf("enter thread1\n");
    printf("this is thread1,g_flag=%d,thread id is %u\n",g_flag,(unsigned int)pthread_self());
    g_flag=1;
    printf("this is thread1,g_flag=%d,thread id is %u\n",g_flag,(unsigned int)pthread_self());
    printf("leave thread1");
    pthread_exit(0);
}

void *thread2()
{
    printf("enter thread2");
    printf("this is thread2,g_flag=%d,thread id is %u\n",g_flag,(unsigned int)pthread_self());
    g_flag=2;
    printf("this is thread2,g_flag=%d,thread id is %u\n",g_flag,(unsigned int)pthread_self());
    printf("leave thread2");
    pthread_exit(0);
}

int main()
{
    //int g_flag=0;
    pthread_t tid1,tid2;
    int rc1=pthread_create(&tid1,NULL,thread1,NULL);
    if(rc1!=0)
    {
        printf("can't create rc1\n");
        return(-1);
    }

    int rc2=pthread_create(&tid2,NULL,thread2,NULL);
    if(rc2!=0)
    {
        printf("can't create rc2\n");
        return(-1);
    }

    sleep(5);
}