RT-Thread 内核学习笔记 - 内核对象操作API

Posted 2021-09-14 RTT小师弟

RT-Thread 内核学习笔记 - 内核对象rt_object

RT-Thread 内核学习笔记 - 内核对象管理

RT-Thread 内核学习笔记 - 内核对象操作API

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RT-Thread 内核学习笔记 - 设备模型rt_device的理解

RT-Thread 内核学习笔记 - 理解defunct僵尸线程
背景

目的还是学习并熟悉RT-Thread 操作系统。
从最简单的对象管理切入
了解操作系统最基本的组成单位：Object

内核对象API

内核对象的主要操作方法：内核文件：object.c中实现

2021-01-24_215832.png
知识点

查看内核文件：object.c，发现的主要的几个知识点

2021-01-24_215932.png
验证与测试

光看内核代码，不如敲一敲（抄一下）。
可以使用模拟器，写几个测试函数，看看对象操作的流程。

测试用例如下：

/ RT-Thread 内核对象学习 /

include <rtthread.h>

struct _obj_type
{

enum rt_object_class_type type;
const char* name;

};

/ 静态的对象定义 /
static struct rt_object _obj[] = { 0 };

/ 测试用，线程对象 /
static const struct _obj_type _obj_tbl[] =
{

{ RT_Object_Class_Thread, "th_01" },
{ RT_Object_Class_Thread, "th_02" },
{ RT_Object_Class_Thread, "th_03" },
{ RT_Object_Class_Thread, "th_04" },
{ RT_Object_Class_Thread, "th_05" },

};

define OBJ_TEST_TBL_SIZE (sizeof(_obj_tbl) / sizeof(_obj_tbl[0]))

/ 静态初始化对象 /
void obj_test_init(void)
{

rt_uint8_t index = 0;
rt_uint8_t obj_size = 0;

for (index = 0; index < OBJ_TEST_TBL_SIZE; index++)
{
    rt_object_init(&_obj[index], _obj_tbl[index].type, _obj_tbl[index].name);
}

}

/ 动态创建对象 obj_test_create thread1 /
void obj_test_create(uint8_t argc, char** argv)
{

struct rt_object* obj = RT_NULL;

if (argc >= 2)
{
    rt_kprintf(" obj_name=%s\\n", argv[1]);
}

obj = rt_object_find(argv[1], RT_Object_Class_Thread);
if (obj != RT_NULL)
{
    rt_kprintf("obj_name=%s, exist!!\\n", obj->name);
    return;
}
else
{
    rt_object_allocate(RT_Object_Class_Thread, argv[1]);
    rt_kprintf("create obj_name=%s\\n", argv[1]);
}

}

/ 对象的打印 /
void obj_test_dump(void)
{

rt_uint8_t index = 0;
rt_uint8_t obj_size = 0;
struct rt_object* obj_pointers[OBJ_TEST_TBL_SIZE + 10] = { 0 };

obj_size = rt_object_get_pointers(RT_Object_Class_Thread, obj_pointers, sizeof(obj_pointers));
rt_kprintf("object init : object size=%d\\n", obj_size);

rt_kprintf("| index |     name     |  flag  |  type  |\\n");
rt_kprintf("+-------+--------------+--------+--------+\\n");
for (index = 0; index < obj_size; index++)
{
    if (obj_pointers[index] == RT_NULL)
    {
        break;
    }
    rt_kprintf("|  %03d  |  %10s  |   %02d   |  0x%02x  |\\n", index,
        obj_pointers[index]->name, obj_pointers[index]->flag,
        obj_pointers[index]->type);
}
rt_kprintf("+-------+--------------+--------+--------+\\n");

}

/ 查找线程对象 /
void obj_test_find(uint8_t argc, char** argv)
{

struct rt_object* obj = RT_NULL;

if (argc >= 2)
{
    rt_kprintf(" obj_name=%s\\n", argv[1]);
}

obj = rt_object_find(argv[1], RT_Object_Class_Thread);
if (obj != RT_NULL)
{
    rt_kprintf("find obj_name=%s\\n", obj->name);
}
else
{
    rt_kprintf("not find obj_name=%s\\n", argv[1]);
}

}

/ 静态对象 detach /
void obj_test_detach(uint8_t argc, char** argv)
{

struct rt_object* obj = RT_NULL;

if (argc >= 2)
{
    rt_kprintf(" obj_name=%s\\n", argv[1]);
}

obj = rt_object_find(argv[1], RT_Object_Class_Thread);
if (obj != RT_NULL)
{
    rt_kprintf("find obj_name=%s\\n", obj->name);
    rt_object_detach(obj);
    rt_kprintf("detach obj_name=%s\\n", obj->name);
}
else
{
    rt_kprintf("not find obj_name=%s\\n", argv[1]);
}

}

/ 动态对象 delete /
void obj_test_delete(uint8_t argc, char** argv)
{

struct rt_object* obj = RT_NULL;

if (argc >= 2)
{
    rt_kprintf(" obj_name=%s\\n", argv[1]);
}

obj = rt_object_find(argv[1], RT_Object_Class_Thread);
if (obj != RT_NULL)
{
    rt_kprintf("find obj_name=%s\\n", obj->name);
    rt_object_delete(obj);
    rt_kprintf("delete obj_name=%s\\n", obj->name);
}
else
{
    rt_kprintf("not find obj_name=%s\\n", argv[1]);
}

}

/ 导出命令 /
MSH_CMD_EXPORT(obj_test_init, object init test);
MSH_CMD_EXPORT(obj_test_create, obj create test);
MSH_CMD_EXPORT(obj_test_dump, object test dump);
MSH_CMD_EXPORT(obj_test_find, object test find);
MSH_CMD_EXPORT(obj_test_detach, object test detach);
MSH_CMD_EXPORT(obj_test_delete, object test del);

学习总结
总结一

发现：tshell 是动态创建的线程
发现：tidle 是静态的线程

msh />obj_test_dump
object init : object size=2

index	name	flag	type
000	tshell	00	0x01
001	tidle0	00	0x81

msh />

总结二

动态对象，创建后，内存占用增加。
动态对象，删除后，内存占用恢复

msh />free
total memory: 8388580
used memory : 5164 / 【5164】 内存原有大小 /
maximum allocated memory: 7336
msh />
msh />obj
obj_test_init
obj_test_create
obj_test_dump
obj_test_find
obj_test_detach
obj_test_delete
msh />obj_test_cre
obj_test_create
msh />obj_test_create hello
obj_name=hello
create obj_name=hello
msh />
msh />fre
free
msh />free
total memory: 8388580
used memory : 5304 / 【5304】 内存占用 /
maximum allocated memory: 7336
msh />
msh />obj_test_delete hello
obj_name=hello
find obj_name=hello
delete obj_name=hello
msh />free
total memory: 8388580
used memory : 5164 / 【5304】，内存占用恢复 /
maximum allocated memory: 7336
msh />

总结三

静态初始化的对象，detach（剔除对象管理）后，内存占用不变。

msh />obj_test_init
msh />ob
obj_test_init
obj_test_create
obj_test_dump
obj_test_find
obj_test_detach
obj_test_delete
msh />obj_test_du
obj_test_dump
msh />obj_test_dump
object init : object size=7

index	name	flag	type
000	th_05	00	0x81
001	th_04	00	0x81
002	th_03	00	0x81
003	th_02	00	0x81
004	th_01	00	0x81
005	tshell	00	0x01
006	tidle0	00	0x81

msh />free
total memory: 8388580
used memory : 5164
maximum allocated memory: 7336
msh />
msh />obj
obj_test_init
obj_test_create
obj_test_dump
obj_test_find
obj_test_detach
obj_test_delete
msh />obj_test_deta
obj_test_detach
msh />obj_test_detach th_04
obj_name=th_04
find obj_name=th_04
detach obj_name=th_04
msh />obj_test_du
obj_test_dump
msh />obj_test_dump
object init : object size=6

index	name	flag	type
000	th_05	00	0x81
001	th_03	00	0x81
002	th_02	00	0x81
003	th_01	00	0x81
004	tshell	00	0x01
005	tidle0	00	0x81

msh />
msh />free
total memory: 8388580
used memory : 5164
maximum allocated memory: 7336

总结

RT-Thread 内核对象的管理并不复杂
相关的知识点，如链表的初始化、插入、遍历、通过链表指针获取对象指针等比较的重要。
掌握好内核对象的基本操作，为后面学习派生对象如：线程对象、设备对象等，打下基础。

原文链接：https://club.rt-thread.org/as...