7.4 线程退出

实验代码

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

int sum = 0;

void *thread_start (void *arg)
{
    
    int i;
    int len = *(int*)arg;
    for (i = 0; i < len; i++)
    {
    
        sum += i;
        sleep (1);
        printf ("sub thread: sum = %d\n", sum);
    }
    printf ("sub thread: exit\n");
    //pthread_exit (NULL);
    exit (0);
}

int main (void)
{
    
    pthread_t tid;
    int arg = 10;
    pthread_create (&tid, NULL, thread_start, (void *) &arg);
    sleep (15);
    pthread_cancel (tid);
    printf ("main thread: sum = %d\n", sum);
    printf ("main thread: exit\n");
    return 0;
}

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

void * thread_start (void *arg)
{
    
    int arg_data = *((int *)arg);
    for (int i = 0; i < 10; i++)
    {
    
        for (int j = 0; j < 50000; j++);
        printf ("received arg%d = %d\n", arg_data, arg_data);
        pthread_exit (NULL);
    }
}

int main (void)
{
    
    pthread_t tid;
    int arg1 = 1;
    int arg2 = 2;
    int ret = pthread_create (&tid, NULL, thread_start, (void *) &arg1);
    if (ret)
    {
    
        perror ("pthread_create");
        exit (EXIT_FAILURE);
    }
    thread_start ((void *) &arg2);
    return 0;
}