5 邮箱发送接收函数中内容格式问题

发布于 2022-07-26 17:39:06 浏览：569 订阅该版

lchnu 2022-07-26

Witness, Understand, Skill

你的代码写错了。以下是一份完整的测试代码：

```c
#include <rtthread.h>
#include <rtdevice.h>

struct msg{
	uint8_t *data_ptr;
	uint32_t data_size;
};

rt_mailbox_t mailbox;
char *test_data = "Test\r\n";

void thread_send(void *parameter);
void thread_recv(void *parameter);

int main(void)
{
	
		rt_thread_t tid;
		
		mailbox = rt_mb_create("mailbox",10,RT_IPC_FLAG_PRIO);
		
		tid = rt_thread_create("send", thread_send, RT_NULL, 1024,4,0);
		rt_thread_startup(tid);
	
		tid = rt_thread_create("recv", thread_recv, RT_NULL, 1024,5,0);
		rt_thread_startup(tid);

return 0;
}

void thread_send(void *parameter)
{
		struct msg *msg_ptr;
	  while(1)
		{
			msg_ptr = (struct msg *)rt_malloc(sizeof(struct msg));
			msg_ptr->data_ptr = (uint8_t *)test_data;
			msg_ptr->data_size = rt_strlen(test_data);
			rt_mb_send(mailbox, (rt_uint32_t)msg_ptr);
			rt_thread_delay(100);		
		}
}

void thread_recv(void *parameter)
{
		struct msg *msg_ptr;
		while(1)
		{
			rt_mb_recv(mailbox, (rt_uint32_t *)&msg_ptr, RT_WAITING_FOREVER);
			rt_kprintf("len = %d, content = %s",msg_ptr->data_size, msg_ptr->data_ptr);
			rt_free(msg_ptr);		
		}
}
```

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20220726/823a3950251f2b7fb8bf7bcb7cd94e39.png.webp)

关键点在于，邮箱收发线程中的两个msg_ptr是来源于线程栈中的变量，虽然名称相同，但是存放在不同的地址。