finsh/>list_thread() 遇到的问题

发布于 2017-09-26 11:37:31 浏览：3355 订阅该版

问题描述：
      使用MDK,编译STM32F4bsp，使用FINSH组件的LIST_THREAD()命令，终端一直输出。但并未死机，闪灯任务执行正常。
问题分析：
      找到内核的如下代码段，添加线程遍历循环因子的打印输出。代码如下。
```
static long _list_thread(struct rt_list_node *list)
{
    struct rt_thread *thread;
    struct rt_list_node *node;
    rt_uint8_t *ptr;

rt_kprintf(" thread  pri  status      sp     stack size max used   left tick  error
");
    rt_kprintf("-------- ---- ------- ---------- ---------- ---------- ---------- ---
");
    for (node = list->next; node != list; node = node->next)
    {
        //下面这行,是自行添加的调试输出代码。
        rt_kprintf("node addr = 0x%04x	list addr = 0x%04x	next addr = 0x%04x
",node,list,node->next);
        thread = rt_list_entry(node, struct rt_thread, list);
        rt_kprintf("%-8.*s 0x%02x", RT_NAME_MAX, thread->name, thread->current_priority);

if (thread->stat == RT_THREAD_READY)        rt_kprintf(" ready  ");
        else if (thread->stat == RT_THREAD_SUSPEND) rt_kprintf(" suspend");
        else if (thread->stat == RT_THREAD_INIT)    rt_kprintf(" init   ");
        else if (thread->stat == RT_THREAD_CLOSE)   rt_kprintf(" close  ");

ptr = (rt_uint8_t *)thread->stack_addr;
        while (*ptr == '#')ptr ++;

rt_kprintf(" 0x%08x 0x%08x 0x%08x 0x%08x %03d
",
                   thread->stack_size + ((rt_uint32_t)thread->stack_addr - (rt_uint32_t)thread->sp),
                   thread->stack_size,
                   thread->stack_size - ((rt_uint32_t) ptr - (rt_uint32_t)thread->stack_addr),
                   thread->remaining_tick,
                   thread->error);
			
    }
    return 0;
}
```

运行结果：
```  | /
- RT -     Thread Operating System
 / |      2.1.0 build Sep 26 2017
 2006 - 2016 Copyright by rt-thread team
finsh>>list_thread()
 thread  pri  status      sp     stack size max used   left tick  error
-------- ---- ------- ---------- ---------- ---------- ---------- ---
node addr = 0x20000cec	list addr = 0x20000054	next addr = 0x20000688
tshell   0x14 ready   0x00000074 0x00000800 0x000001b0 0x00000004 000
node addr = 0x20000688	list addr = 0x20000054	next addr = 0x20000cec
tidle    0x1f ready   0x00000048 0x00000400 0x00000048 0x00000020 000
node addr = 0x20000cec	list addr = 0x20000054	next addr = 0x20000688
tshell   0x14 ready   0x00000074 0x00000800 0x000001b0 0x0000000a 000
node addr = 0x20000688	list addr = 0x20000054	next addr = 0x20000cec
tidle    0x1f ready   0x00000048 0x00000400 0x00000048 0x00000020 000
node addr = 0x20000cec	list addr = 0x20000054	next addr = 0x20000688
tshell   0x14 ready   0x00000074 0x00000800 0x000001b0 0x00000002 000```

2次分析：
线程链表 在地址 0x20000cec 和 0x20000688 循环跳转，且永不满足循环跳出条件。