#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
void print_message_function (void *ptr);

int main()
{
    int tmp1, tmp2;
    void *retval;
    pthread_t thread1, thread2;
    char *message1 = "thread1";
    char *message2 = "thread2";

    int ret_thrd1, ret_thrd2;

    ret_thrd1 = pthread_create(&thread1, NULL, (void *)&print_message_function, (void *) message1);
    ret_thrd2 = pthread_create(&thread2, NULL, (void *)&print_message_function, (void *) message2);

    // 线程创建成功，返回0,失败返回失败号
    if (ret_thrd1 != 0) {
        printf("线程1创建失败\n");
    } else {
        printf("线程1创建成功\n");
    }

    if (ret_thrd2 != 0) {
        printf("线程2创建失败\n");
    } else {
        printf("线程2创建成功\n");
    }

    //同样，pthread_join的返回值成功为0
    tmp1 = pthread_join(thread1, &retval);
    // printf("thread1 return value(retval) is %d\n", (int)retval);
    printf("thread1 return value(tmp) is %d\n", tmp1);
    if (tmp1 != 0) {
        printf("cannot join with thread1\n");
    }
    printf("thread1 end\n");

    tmp2 = pthread_join(thread2, &retval);
    // printf("thread2 return value(retval) is %d\n", (int)retval);
    printf("thread2 return value(tmp) is %d\n", tmp1);
    if (tmp2 != 0) {
        printf("cannot join with thread2\n");
    }
    printf("thread2 end\n");

}

void print_message_function( void *ptr ) {
    int i = 0;
    for (i; i<5; i++) {
        sleep(3);
        printf("%s:%d\n", (char *)ptr, i);
    }
}

gcc duojincheng.c -o a -lpthread

线程1创建成功
线程2创建成功
thread2:0
thread1:0
thread2:1
thread1:1
thread2:2
thread1:2
thread1:3
thread2:3
thread1:4
thread1 return value(tmp) is 0
thread1 end
thread2:4
thread2 return value(tmp) is 0
thread2 end