文章目录
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- [RT-Thread 堆内存 检查命令 free 实现及介绍](#RT-Thread 堆内存 检查命令 free 实现及介绍)
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- [rt_memory_info 函数验证](#rt_memory_info 函数验证)
RT-Thread 堆内存 检查命令 free 实现及介绍
在RT-Thread系统中，通常可以通过rt_memory_info函数获取当前的堆内存使用信息，然后你可以包装这个函数来显示剩余的堆空间。rt_memory_info实现见：
rt-thread/src/mem.c:
c
void rt_memory_info(rt_uint32_t *total,
rt_uint32_t *used,
rt_uint32_t *max_used)
{
if (total != RT_NULL)
*total = mem_size_aligned;
if (used != RT_NULL)
*used = used_mem;
if (max_used != RT_NULL)
*max_used = max_mem;
}rt-thread 中其实已经实现了cmd_free 函数，可以使用这个函数来查看当前堆的使用情况：
c
#ifdef RT_USING_HEAP
int cmd_free(int argc, char **argv)
{
rt_uint32_t total = 0, used = 0, max_used = 0;
rt_memory_info(&total, &used, &max_used);
rt_kprintf("total : %d\n", total);
rt_kprintf("used : %d\n", used);
rt_kprintf("maximum : %d\n", max_used);
return 0;
}
MSH_CMD_EXPORT_ALIAS(cmd_free, free, Show the memory usage in the system.);
#endif /* RT_USING_HEAP */所以在终端执行free 命令即可查看堆的使用情况：
shell
msh >help
RT-Thread shell commands:
list - list all commands in system
list_timer - list timer in system
list_mempool - list memory pool in system
list_memheap - list memory heap in system
list_msgqueue - list message queue in system
list_mailbox - list mail box in system
list_mutex - list mutex in system
list_event - list event in system
list_sem - list semaphore in system
list_thread - list thread
version - show RT - Thread version information
clear - clear the terminal screen
hello - say hello world
free - Show the memory usage in the system.
ps - List threads in the system.
help - RT - Thread shell help.rt_memory_info 函数验证
如下实现了一个测试函数，在函数开始的时候查看当前堆使用了多少，然后再进行rt_malloc(1024) 之后再查看下堆使用了多少，通过前后对比可以看出rt_memory_info函数获取的信息是否正确。
c
#include <rtthread.h>
#include <pthread.h>
#define TEST_MALLOC_SIZE 1024
static int mem_check_test(void)
{
char *ptr = RT_NULL;
rt_uint32_t total = 0, used_pre = 0, max_used = 0;
rt_uint32_t used_next = 0;
rt_memory_info(&total, &used_pre, &max_used);
ptr = (char *)rt_malloc(TEST_MALLOC_SIZE);
if (ptr == RT_NULL) {
rt_kprintf("mem check test failed\n");
return -RT_ENOMEM;
}
rt_memory_info(&total, &used_next, &max_used);
if ((used_next - used_pre) != TEST_MALLOC_SIZE + 16) {
rt_kprintf("mem check test failed\n"
"mem used_pre: %d, mem used_next:%d\n",
used_pre, used_next);
rt_free(ptr);
return -RT_ERROR;
}
rt_kprintf("mem check test ok\n");
rt_free(ptr);
return RT_EOK;
}
INIT_APP_EXPORT(mem_check_test);关于free命令的本地测试如下：
通过执行free命令之后可以看到一共有多少heap和已经使用了多少。
通常需要在跑完测试用例后不能影响heap的大小，简单点说就是你的测试case不能导致内存泄露。