在实验1的基础上提出两个问题
问题：1.如何给线程执行函数传入结构体参数
2.如何获取线程执行函数的返回值
3.线程退出和取消
pthread_join(turtle,(void **)&result);//第二个参数就会保留线程执行函数的返回值
线程退出和取消：return 语句
pthread_exit()函数
pthread_cancel()函数，被同一进程的其他线程取消
tips：exit()函数会退出整个进程
实验源码如下：
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
typedef struct
{
char name[20];
int time;
int start;
int end;
}RaceArg;
void * th_fn(void *arg)
{
RaceArg *r=(RaceArg *)arg;
for(int i=r->start;i<r->end;i++)
{
printf("%lx run %d, name=%s\n",pthread_self(),i,r->name);
usleep(r->time);
}
//return (void*)0;
pthread_exit((void*)(r->end-r->start));
}
int main(void)
{
int err;
pthread_t rabbit,turtle;
RaceArg r_a={"rabbit",10000,2,50};
RaceArg r_b={"turtle",10000,3,100};
if((err=pthread_create(&rabbit,NULL,th_fn,(void *)&r_a))!=0)
{
perror("pthread_create error");
}
if((err=pthread_create(&turtle,NULL,th_fn,(void *)&r_b))!=0)
{
perror("pthread_create error");
}
int *result;
pthread_join(rabbit,(void **)&result);
printf("the result is %d\n",(int)result);
pthread_join(turtle,(void **)&result);
printf("the result is %d\n",(int)result);
printf("control thread id: %lx\n",pthread_self());
printf("finished!\n");
return 0;
}
实验结果如下：
7f4ed2118700 run 3, name=turtle
7f4ed2919700 run 2, name=rabbit
7f4ed2118700 run 4, name=turtle
7f4ed2919700 run 3, name=rabbit
7f4ed2118700 run 5, name=turtle
7f4ed2919700 run 4, name=rabbit
7f4ed2118700 run 6, name=turtle
7f4ed2919700 run 5, name=rabbit
7f4ed2118700 run 7, name=turtle
7f4ed2919700 run 6, name=rabbit
7f4ed2118700 run 8, name=turtle
7f4ed2919700 run 7, name=rabbit
7f4ed2118700 run 9, name=turtle
7f4ed2919700 run 8, name=rabbit
7f4ed2118700 run 10, name=turtle
7f4ed2919700 run 9, name=rabbit
7f4ed2118700 run 11, name=turtle
7f4ed2919700 run 10, name=rabbit
7f4ed2118700 run 12, name=turtle
7f4ed2919700 run 11, name=rabbit
7f4ed2118700 run 13, name=turtle
7f4ed2919700 run 12, name=rabbit
7f4ed2118700 run 14, name=turtle
7f4ed2919700 run 13, name=rabbit
7f4ed2118700 run 15, name=turtle
7f4ed2919700 run 14, name=rabbit
7f4ed2118700 run 16, name=turtle
7f4ed2919700 run 15, name=rabbit
7f4ed2118700 run 17, name=turtle
7f4ed2919700 run 16, name=rabbit
7f4ed2118700 run 18, name=turtle
7f4ed2919700 run 17, name=rabbit
7f4ed2118700 run 19, name=turtle
7f4ed2919700 run 18, name=rabbit
7f4ed2118700 run 20, name=turtle
7f4ed2919700 run 19, name=rabbit
7f4ed2118700 run 21, name=turtle
7f4ed2919700 run 20, name=rabbit
7f4ed2118700 run 22, name=turtle
7f4ed2919700 run 21, name=rabbit
7f4ed2118700 run 23, name=turtle
7f4ed2919700 run 22, name=rabbit
7f4ed2118700 run 24, name=turtle
7f4ed2919700 run 23, name=rabbit
7f4ed2118700 run 25, name=turtle
7f4ed2919700 run 24, name=rabbit
7f4ed2118700 run 26, name=turtle
7f4ed2919700 run 25, name=rabbit
7f4ed2118700 run 27, name=turtle
7f4ed2919700 run 26, name=rabbit
7f4ed2118700 run 28, name=turtle
7f4ed2919700 run 27, name=rabbit
7f4ed2118700 run 29, name=turtle
7f4ed2919700 run 28, name=rabbit
7f4ed2118700 run 30, name=turtle
7f4ed2919700 run 29, name=rabbit
7f4ed2118700 run 31, name=turtle
7f4ed2919700 run 30, name=rabbit
7f4ed2118700 run 32, name=turtle
7f4ed2919700 run 31, name=rabbit
7f4ed2118700 run 33, name=turtle
7f4ed2919700 run 32, name=rabbit
7f4ed2118700 run 34, name=turtle
7f4ed2919700 run 33, name=rabbit
7f4ed2118700 run 35, name=turtle
7f4ed2919700 run 34, name=rabbit
7f4ed2118700 run 36, name=turtle
7f4ed2919700 run 35, name=rabbit
7f4ed2118700 run 37, name=turtle
7f4ed2919700 run 36, name=rabbit
7f4ed2118700 run 38, name=turtle
7f4ed2919700 run 37, name=rabbit
7f4ed2118700 run 39, name=turtle
7f4ed2919700 run 38, name=rabbit
7f4ed2118700 run 40, name=turtle
7f4ed2919700 run 39, name=rabbit
7f4ed2118700 run 41, name=turtle
7f4ed2919700 run 40, name=rabbit
7f4ed2118700 run 42, name=turtle
7f4ed2919700 run 41, name=rabbit
7f4ed2118700 run 43, name=turtle
7f4ed2919700 run 42, name=rabbit
7f4ed2118700 run 44, name=turtle
7f4ed2919700 run 43, name=rabbit
7f4ed2118700 run 45, name=turtle
7f4ed2919700 run 44, name=rabbit
7f4ed2118700 run 46, name=turtle
7f4ed2919700 run 45, name=rabbit
7f4ed2118700 run 47, name=turtle
7f4ed2919700 run 46, name=rabbit
7f4ed2118700 run 48, name=turtle
7f4ed2919700 run 47, name=rabbit
7f4ed2118700 run 49, name=turtle
7f4ed2919700 run 48, name=rabbit
7f4ed2118700 run 50, name=turtle
7f4ed2919700 run 49, name=rabbit
7f4ed2118700 run 51, name=turtle
the result is 48
7f4ed2118700 run 52, name=turtle
7f4ed2118700 run 53, name=turtle
7f4ed2118700 run 54, name=turtle
7f4ed2118700 run 55, name=turtle
7f4ed2118700 run 56, name=turtle
7f4ed2118700 run 57, name=turtle
7f4ed2118700 run 58, name=turtle
7f4ed2118700 run 59, name=turtle
7f4ed2118700 run 60, name=turtle
7f4ed2118700 run 61, name=turtle
7f4ed2118700 run 62, name=turtle
7f4ed2118700 run 63, name=turtle
7f4ed2118700 run 64, name=turtle
7f4ed2118700 run 65, name=turtle
7f4ed2118700 run 66, name=turtle
7f4ed2118700 run 67, name=turtle
7f4ed2118700 run 68, name=turtle
7f4ed2118700 run 69, name=turtle
7f4ed2118700 run 70, name=turtle
7f4ed2118700 run 71, name=turtle
7f4ed2118700 run 72, name=turtle
7f4ed2118700 run 73, name=turtle
7f4ed2118700 run 74, name=turtle
7f4ed2118700 run 75, name=turtle
7f4ed2118700 run 76, name=turtle
7f4ed2118700 run 77, name=turtle
7f4ed2118700 run 78, name=turtle
7f4ed2118700 run 79, name=turtle
7f4ed2118700 run 80, name=turtle
7f4ed2118700 run 81, name=turtle
7f4ed2118700 run 82, name=turtle
7f4ed2118700 run 83, name=turtle
7f4ed2118700 run 84, name=turtle
7f4ed2118700 run 85, name=turtle
7f4ed2118700 run 86, name=turtle
7f4ed2118700 run 87, name=turtle
7f4ed2118700 run 88, name=turtle
7f4ed2118700 run 89, name=turtle
7f4ed2118700 run 90, name=turtle
7f4ed2118700 run 91, name=turtle
7f4ed2118700 run 92, name=turtle
7f4ed2118700 run 93, name=turtle
7f4ed2118700 run 94, name=turtle
7f4ed2118700 run 95, name=turtle
7f4ed2118700 run 96, name=turtle
7f4ed2118700 run 97, name=turtle
7f4ed2118700 run 98, name=turtle
7f4ed2118700 run 99, name=turtle
the result is 97
control thread id: 7f4ed311c700
finished!