代码运行结果于我的预期不符

发布于 2023-11-29 15:00:35 浏览：260 订阅该版

代码：
```c
/* mailbox_sample.c
 *
 * created: 2023/11/29
 * author:
 */
#include <rtthread.h>
#include <rthw.h>

static rt_thread_t tid1 = RT_NULL;
static rt_thread_t tid2 = RT_NULL;

#define THREAD_PRIORITY       25
#define THREAD_STACK_SIZE     512
#define THREAD_TIMESLICE      5

static struct rt_mailbox mb;
static char mb_pool[128];

static char mb_str1[] = "I' am a mail";
static char mb_str2[] = "this is another mail!";

static void thread1_entry(void* parameter)
{
    unsigned char* str;
    while(1)
    {
        rt_kprintf("thread1: try to recv a mail\n");

if(rt_mb_recv(&mb, (rt_uint32_t*)&str, RT_WAITING_FOREVER) == RT_EOK)
        {
            rt_kprintf("thread1: get a mail, the content: %s\n", str);

rt_thread_delay(10);
        }
    }
}

static void thread2_entry(void* parameter)
{
    rt_uint8_t count;
    count = 0;
    while(1)
    {
        count++;
        if(count & 0x1)
        {
            rt_mb_send(&mb, (rt_uint32_t)&mb_str1[0]);
        }
        else
        {
            rt_mb_send(&mb, (rt_uint32_t)&mb_str2[0]);
        }

rt_thread_delay(20);
    }
}

int mailbox_sample(void)
{
    rt_mb_init(&mb, "mbt", &mb_pool[0], sizeof(mb_pool)/4, RT_IPC_FLAG_FIFO);

tid1 = rt_thread_create("thread1", thread1_entry, RT_NULL, THREAD_STACK_SIZE, THREAD_PRIORITY, THREAD_TIMESLICE);

if(tid1 != RT_NULL)
        rt_thread_startup(tid1);

tid2 = rt_thread_create("thread2", thread2_entry, RT_NULL, THREAD_STACK_SIZE, THREAD_PRIORITY, THREAD_TIMESLICE);

if(tid2 != RT_NULL)
        rt_thread_startup(tid2);

return 0;
}

MSH_CMD_EXPORT(mailbox_sample, send receive test);
```

结果：
```
msh />mailbox_sample
msh />thread1: try to recv a mail
threa   at     =FFFFFFFE
,   v0     =0000007C	,   v1     =8021B474	,   a0     =80247D38	,   a1     =00000000
,   a2     =000004E0	,   a3     =80247E1C	,   t0     =1000FF02	,   t1     =23232323
,   t2     =23232323	,   t3     =23232323	,   t4     =23232323	,   t5     =23232323
,   t6     =23232323	,   t7     =23232323	,   s0     =1000FF03	,   s1     =23232323
,   s2     =23232323	,   s3     =23232323	,   s4     =23232323	,   s5     =23232323
,   s6     =23232323	,   s7     =23232323	,   t8     =23232323	,   t9     =23232323
,   k0     =8021C208	,   k1     =0000007C	,   gp     =80241B08	,   sp     =80245A58
,   fp     =80245A58	,   ra     =8022AE94	,   mdlo   =23232323	,   mdhi   =23232323
,   badva  =0000007C	,   cause  =8000000C	,   status =1000FF02	,   epc    =8022FDBC
,
CPU Exception: TLB Store
```