线程让出时的一个小问题

发布于 2014-09-01 17:33:10 浏览：2958 订阅该版

[viewtopic.php?f=28&t=1895](http://www.rt-thread.org/phpBB3/viewtopic.php?f=28&t=1895) 
参考上边的例子，实验线程让出。
线程的创建代码如下：
```void rt_thread_test(void)
{
    tid2 = rt_thread_create("yield1",yield_test1,RT_NULL,2048,10,20);
    if(tid2 != RT_NULL)
        rt_thread_startup(tid2);
    tid2 = rt_thread_create("yield2",yield_test2,RT_NULL,2048,10,20);
    if(tid2 != RT_NULL)
        rt_thread_startup(tid2);
}```
两个线程很简单：就是输出信息，然后让出CPU
```void yield_test1(void* parameter)
{
    rt_uint32_t count = 0;
    while(1)
    {
        rt_thread_yield();
        rt_kprintf("thread test1 count:%d
",count++);

}
}
void yield_test2(void* parameter)
{
    rt_uint32_t count = 0;
    while(1)
    {
        rt_kprintf("thread test2 count:%d
",count++);
        rt_thread_yield();
    }
}```

可最终结果却有点问题：
前面都是正常的，后边就开始乱了。如低93次输出，显示test2线程输出一些，然后又来了一个test2线程。把中间的输出打断了

而且每次复位，都是93次输出的时候出现这种情况。谁能帮分析下这是什么原因啊？

```thread test1 count:91
thread test2 count:92
threthread test2 count:93
ad test2 count:93
thread test2 count:94
thread test1 count:93
thread test2 count:95
thread test1 count:94
thread test2 count:96
thread test1 count:95
thread test2 count:97
thread test1 count:96
thread test2 count:98
thread test1 count:97
thread test2 count:99
thread test1 count:98
thread test2 count:100
thread test1 count:99
thread test2 count:101
thread test1 count:100
thread test2 count:102
thread test1 count:101
thread test2 count:103
thread test1 count:102
thread test2 count:104
thread test1 count:103
thread test2 counthread test1 count:104
t:104
thread test1 count:105
thread test2 count:106
thread test1 count:106
thread test2 count:107
thread test1 count:107
thread test2 count:108```