RT-Thread-15天入门RT-THREAD学习-第三天(线程的创建与删除)RT-Thread问答社区

15天入门RT-THREAD学习-第三天(线程的创建与删除)

发布于 2018-05-19 14:03:24 浏览：2103 订阅该版

1、代码解释

2、线程的组成：
A\线程代码

B\线程控制块
    线程的优先级：数值越小优先级超高，相同优先级的线程采用时间片轮询处理

C\线程堆栈
    先设置一个比较大的值，然后通过观察来适当调整

3、线程的代码形式：
A\无限循环形式
```func
｛
	while(1)
	{
		tr_thread_delay();//必须让出CPU使用权，否则其他低优先级线程无法运行
	}
｝```

B\顺序执行形式
```func
｛
   statement1;
   statement2;
   ...

｝```
运行结束后由空闲任务将其从运行队列中删除并回收其资源

4、静态线程和动态线程
主要的区别是线程的分配方式：
静态线程即线程堆栈在创建线程时静态分配内存
静态线程创建API为rt_thread_init
静态线程删除API为rt_thread_detach(&tid)

动态线程即线程堆栈在创建线程时动态申请内存
动态线程创建API为rt_thread_creat
动态线程删除API为rt_rhread_delete(&tid)

线程均使用rt_thread_startup()启动

作业：自动动手将tid2改写为静态创建方式
```#include <rtthread.h>
#include "thread.h"

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

static struct rt_thread tid1;
ALIGN(RT_ALIGN_SIZE)
static rt_uint8_t tid1_stack[THREAD_STACK_SIZE];

static struct rt_thread tid2;
ALIGN(RT_ALIGN_SIZE)
static rt_uint8_t tid2_stack[THREAD_STACK_SIZE];

static void thread1_entry(void *parameter)
{
    rt_uint32_t count = 0;
    while(1)
    {
        rt_kprint("thread count: %d<br>",count++);
        count++;
    }
}
static void thread2_cleanup(struct rt_thread *tid)
{
    if(tid != &tid2)
    {
        return;
    }
    rt_kprintf("thread1_end<br>");
}

static void thread2_entry(void *parameter)
{
    rt_thread_delay(10);
    rt_thread_delete(tid1);
    rt_thread_delay(10);
}

static void thread2_cleanup(struct rt_thread *tid)
{
    if(tid != &tid2)
    {
        return;
    }
    rt_kprintf("thread2_end<br>");
}

int thread_sample_init()
{
    rt_err_t res;
    res = rt_thread_init(&tid1,
                         "t1",
                         thread1_entry,
                         RT_NULL,
                         tid1_stack,
                         THREAD_STACK_SIZE,
                         THREAD_PRIORITY,
                         THREAD_TIMESLICE);
    if(res == RT_EOK)
    {
        tid1->cleanup = thread1_cleanup;
        rt_thread_startup(&tid1);
    }
    
    res = rt_thread_init(&tid2,
                         "t2",
                         thread2_entry,
                         RT_NULL,
                         tid2_stack,
                         THREAD_STACK_SIZE,
                         THREAD_PRIORITY,
                         THREAD_TIMESLICE);
    if(res == RT_EOK)
    {
        tid2->cleanup = thread2_cleanup;
        rt_thread_startup(&tid2);
    }
    
    return 0;
}
```