dynmem_sample.c

/*
 * Copyright (c) 2006-2018, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date Author Notes
 * 2018-08-24 yangjie the first version
 */

/*
 * 程序清单：动态内存管理例程
 *
 * 这个程序会创建一个动态的线程，这个线程会动态申请内存并释放
 * 每次申请更大的内存，当申请不到的时候就结束
 */
#include <rtthread.h>

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

/* 线程入口 */
void thread1_entry(void *parameter)
{
 int i;
 char *ptr = RT_NULL; /* 内存块的指针 */

 for (i = 0; ; i++)
 {
 /* 每次分配 (1 << i) 大小字节数的内存空间 */
 ptr = rt_malloc(1 << i);

 /* 如果分配成功 */
 if (ptr != RT_NULL)
 {
 rt_kprintf("get memory :%d byte\n", (1 << i));
 /* 释放内存块 */
 rt_free(ptr);
 rt_kprintf("free memory :%d byte\n", (1 << i));
 ptr = RT_NULL;
 }
 else
 {
 rt_kprintf("try to get %d byte memory failed!\n", (1 << i));
 return;
 }
 }
}

int dynmem_sample(void)
{
 rt_thread_t tid = RT_NULL;

 /* 创建线程1 */
 tid = rt_thread_create("thread1",
 thread1_entry, RT_NULL,
 THREAD_STACK_SIZE,
 THREAD_PRIORITY,
 THREAD_TIMESLICE);
 if (tid != RT_NULL)
 rt_thread_startup(tid);

 return 0;
}

/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(dynmem_sample, dynmem sample);