单片机简单的时间片轮询

只看该作者 · 2024-9-27 15:30

时间片轮询调度
1.创建一个结构体链表

typedef struct taskMember
{
pfuntion taskName;
volatile uint32_t tick;
uint32_t taskID;
uint32_t taskStatus;
struct taskMember *listNext;
}task_t;
2.声明一个链表头。

static task_t taskListHead;
task_t *currentTask = 0;
3.任务创建，每个任务都对应唯一id号码

uint32_t createTask(pfuntion taskName,uint32_t taskID)
{
task_t *listHead = &taskListHead;
task_t *temp = 0;
uint32_t ret = 1;

temp = (task_t *)malloc(sizeof(task_t));
if(temp == 0)
{
      free(temp);
      return 0;
}

temp->taskName = taskName;
temp->taskStatus = 0;
temp->taskID = taskID;
temp->listNext = 0;
while(listHead->listNext != 0)
{
      listHead = listHead->listNext;
      if(listHead->taskID == taskID)
      {
         ret = 0;
         free(temp);
         break;
      }
}
if(ret == 1)
{
      listHead->listNext = temp;
}

return ret;
}

4.任务调度，在中断定时器中调用，一般1ms一次

void taskScheduler(void)
{
task_t *listHead = &taskListHead;

while(listHead->listNext != 0)
{
      listHead = listHead->listNext;
      if(listHead->tick > 0)
      {
         listHead->tick--;
      }
}
}
5.任务延时

void taskDelayMs(uint32_t tick)
{
currentTask->tick = tick;
}
6.任务开始，在主循环调用

void taskRuning(void)
{
task_t *listHead = taskListHead.listNext;

while(1)
{
      if(listHead->tick == 0 && listHead->taskStatus == 0)
      {
         currentTask = listHead;
         listHead->taskName();
         if(listHead->tick < 1)
         {
            listHead->tick = 1;
         }
      }
      if(listHead->listNext != 0)
      {
         listHead = listHead->listNext;
      }
      else
      {
         listHead = taskListHead.listNext;
      }
}

}
7.任务挂起和恢复

void taskDelete(uint32_t taskID)
{
task_t *listHead = &taskListHead;
task_t *last = &taskListHead;

while(listHead-> listNext != 0)
{
      listHead = listHead->listNext;
      if(listHead->taskID == taskID)
      {
         last->listNext = listHead->listNext;
         free(listHead);
         break;
      }
      else
      {
         last = listHead;
      }
}
}

task_t * searchList(task_t * head,uint32_t taskID)
{
task_t * temp = head;

while(temp->listNext != 0)
{
      temp = temp->listNext;
      if(temp->taskID == taskID)
      {
         break;
      }
}
return  currentTask;
}
//任务挂起
void taskPending(uint32_t taskID)
{
   task_t *temp = searchList(&taskListHead,taskID);
   if(temp != 0)
   {
      temp->taskStatus = 1;
   }
}

//任务恢复
void taskResume(uint32_t taskID)
{
   task_t *temp = searchList( &taskListHead,taskID);
   if(temp != 0)
   {
      temp->taskStatus = 0;
      temp->tick = 0;
   }
}
这是一个简单的任务轮询调度，可以创建无数个，方便简单。

/****************************使用例子**********************/
void ledtask(void)//led间隔500ms翻转一次
{