Free RTOS day3

1.思维导图

2.重新实现一遍任务调度算法的代码。

（1）抢占式调度

#include "FreeRTOS.h"
#include "task.h"
#include "main.h"
#include "cmsis_os.h"
#include <stdio.h>

osThreadId_t defaultTaskHandle;
const osThreadAttr_t defaultTask_attributes = {
  .name = "defaultTask",
  .stack_size = 128 * 4,
  .priority = (osPriority_t) osPriorityNormal,
};

//比默认任务优先级高的参数
osThreadId_t myTask02Handle;
const osThreadAttr_t myTask02_attributes = {
  .name = "myTask02",
  .stack_size = 128 * 4,
  .priority = (osPriority_t) osPriorityNormal1,
};

void StartDefaultTask(void *argument);
void myTask02(void *argument);

void StartDefaultTask(void *argument)
{
  /* USER CODE BEGIN StartDefaultTask */
  /* Infinite loop */

  for(;;)
  {
		printf("StartDefaultTask is start\r\n");
		//创建一个任务优先级比StartDefaultTask要高的任务
		if(myTask02Handle==NULL)
		{
			myTask02Handle=osThreadNew(myTask02,NULL,&myTask02_attributes);
		}		
		printf("StartDefaultTask is end\r\n");
    osDelay(500);
  }
}

void myTask02(void *argument)
{
  /* USER CODE BEGIN StartTask02 */
  /* Infinite loop */
  for(;;)
  {
		printf("myTask02 is running\r\n");
        osDelay(500);
  }
  /* USER CODE END StartTask02 */
}

（2）时间片轮转

osThreadId_t defaultTaskHandle;
const osThreadAttr_t defaultTask_attributes = {
  .name = "defaultTask",
  .stack_size = 128 * 4,
  .priority = (osPriority_t) osPriorityNormal,
};
/* Definitions for myTask02 */
//优先级一样
osThreadId_t StartTask02Handle;
const osThreadAttr_t StartTask02_attributes = {
  .name = "StartTask02",
  .stack_size = 128 * 4,
  .priority = (osPriority_t) osPriorityNormal,
};

void StartDefaultTask(void *argument);
void StartTask02(void *argument);

/* creation of defaultTask */
  defaultTaskHandle = osThreadNew(StartDefaultTask, NULL, &defaultTask_attributes);

  /* creation of myTask02 */
  StartTask02Handle = osThreadNew(StartTask02, NULL, &StartTask02_attributes);

void StartDefaultTask(void *argument)
{
  /* USER CODE BEGIN StartDefaultTask */
  /* Infinite loop */

  int i=0;
  for(;;)
  {
		printf("StartDefaultTask is start\r\n");
		//创建一个任务优先级比StartDefaultTask要高的任务
		for(i=0;i<90000000;i++)
		{
			;//执行，消耗时间
		}		
		printf("StartDefaultTask is end\r\n");
    osDelay(500);
  }
  /* USER CODE END StartDefaultTask */
}
//实现任务2调度函数
void StartTask02(void *argument)
{
  /* USER CODE BEGIN StartTask02 */
  /* Infinite loop */
  for(;;)
  {
		printf("StartTask02\r\n");
    osDelay(500);
  }
  /* USER CODE END StartTask02 */
}