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

int num = 0; //设置为全局变量，在全局区域，共享

void* myfun(void* arg);

pthread_mutex_t mtx;
int main()
{
    pthread_t id[2];
    pthread_mutex_init(&mtx,NULL);
    for (int i = 0; i < 2; i++) {
        pthread_create(&(id[i]), NULL, myfun, NULL);
  //  	printf("mian: %d : %d \n", num,pthread_self());
    }
   
    pthread_join(id[0],NULL); 
    pthread_join(id[1],NULL); 
    printf("%d",num);
    return 0;

}

void* myfun(void* arg)
{
    int i;
    for(i=0;i<100000000;i++){
//	pthread_mutex_lock(&mtx);
    	num++;
//	pthread_mutex_unlock(&mtx);
 //   	printf("%d : %d \n",num,pthread_self());	
    }
    
    return NULL;
}