线程属性设置

 

/*
 * 设置线程属性——线程的分离状态
 * Lzy 2011-6-18
 */

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

int thread_flag = 1;

void *mythread(void *arg)        //定义新线程运行函数
{
    printf("Thread is running\n");
    sleep(3);
    printf("Thread is exiting now\n");
    thread_flag = 0;
    pthread_exit(NULL);
}

int main(void)
{
    pthread_t tid;                    //定义线程描述符
    pthread_attr_t thread_attr;            //定义线程属性对像

    pthread_attr_init(&thread_attr);                //线程属性初始化
    pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED);    //将线程设置为分离状态

    if(pthread_create(&tid, &thread_attr, mythread, NULL))    //创建新线程，并修改属性
    {
        printf("pthread_create error\n");
        exit(0);
    }

    while(thread_flag)
    {
        printf("Wait for thread finished\n");
        sleep(1);
    }
    printf("Thread finish\n");
    return 0;
}

/******************************************************************************
* FILE: bug2.c
* DESCRIPTION:
* A "hello world" Pthreads program that dumps core. Figure out why and
* then fix it.
* 修改之后的文件
******************************************************************************/
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>

#define NTHREADS    8
#define ARRAY_SIZE 5000000

void * Hello(void * threadid)
{
    double A[ARRAY_SIZE];
    int i;
    long tid;

    tid = (long)threadid;
    sleep(3);
    for (i=0; i<ARRAY_SIZE; i++)
    {
        A[i] = i * 1.0;
    }
    printf("%ld: Hello World! %f\n", tid, A[ARRAY_SIZE-1]);
    pthread_exit(NULL);
}

int main(int argc, char *argv[])
{
    pthread_t threads[NTHREADS];
    size_t stacksize;
    pthread_attr_t attr;
    int rc;
    long t;

    pthread_attr_init(&attr);
    pthread_attr_setstacksize(&attr, sizeof(double)*ARRAY_SIZE + 10485760);
    pthread_attr_getstacksize(&attr, &stacksize);
    printf("Thread stack size = %li bytes (hint, hint)\n",stacksize);
    for(t=0;t<NTHREADS;t++)
    {
        rc = pthread_create(&threads[t], &attr, Hello, (void *)t);
        if (rc)
        {
            printf("ERROR; return code from pthread_create() is %d\n", rc);
            exit(-1);
        }
    }
    printf("Created %ld threads.\n", t);
    for(t=0;t<NTHREADS;t++)
    {
        rc = pthread_join(threads[t], NULL);
        if(rc)
        {
            printf("ERROR; return code from pthread_join() is %d\n", rc);
            exit(-1);
        }
    }
    pthread_attr_destroy(&attr);
    return 0;
}