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

int num = 13; //设置为全局变量，在全局区域，共享

void* myfun(void* arg);

int main(int argc, char *argv[])
{
    void* p = (void *)&num;  //传一个地址进去（voi* 也是 4 个字节）
    pthread_t id[5] = {0};
    for (int i = 0; i < 5; i++) {
        pthread_create(&(id[i]), NULL, myfun, p);
        printf("i = %d, thread id: %ld\n", i, id[i]);
    }
    
    sleep(2);
    return 0;
}

void* myfun(void* arg)
{
    printf("num = %d, child thread id: %ld\n", (*((int *)arg))++, pthread_self());
    return NULL;
}