Linux多线程pthread_key_create

Linux 多线程应用编程 pthread_key_create

示例代码：

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


pthread_key_t key;
struct for_test {
    int i;
    float k;
};


void *thread1 (void *arg)
{
    struct for_test data;
    data.i = 1;
    data.k = 1.23;
    pthread_setspecific (key, &data);
    printf ("struct_data的地址为 0x%p\n", &(data));
    printf ("thread1 pthread_getspecific(key)返回的地址为:0x%p\n", (struct for_test *)pthread_getspecific(key));
    printf ("thread1 第一次利用 pthread_getspecific(key)打印线程中与key关联的结构体中成员值:\ndata.i:%d\ndata.k: %f\n", ((struct for_test*)pthread_getspecific (key))->i, ((struct for_test *)pthread_getspecific(key))->k);


    sleep(2);
    printf ("\n\nthread1 第二次利用 pthread_getspecific(key)打印线程中与key关联的结构体中成员值:\ndata.i:%d\ndata.k: %f\n", ((struct for_test*)pthread_getspecific (key))->i, ((struct for_test *)pthread_getspecific(key))->k);

}


void *thread2 (void *arg)
{
    int num = 10;
    sleep (1);
    printf ("\n\nthread2 变量 num 的地址为 0x%p\n",  &num);
    pthread_setspecific (key, &num);
    printf ("thread2 pthread_getspecific(key)返回的地址为:0x%p\n", (int *)pthread_getspecific(key));
    printf ("thread2 利用 pthread_getspecific(key)打印线程中与key关联的整型变量temp 值:%d, k = %f\n", *((int *)pthread_getspecific(key)), ((struct for_test *)pthread_getspecific(key))->k);
}


int main (void)
{
    pthread_t tid1, tid2;
    pthread_key_create (&key, NULL);
    pthread_create (&tid1, NULL, (void *)thread1, NULL);
    pthread_create (&tid2, NULL, (void *)thread2, NULL);
    pthread_join (tid1, NULL);
    pthread_join (tid2, NULL);
    pthread_key_delete (key);


    return 0;
}