怎么找网站帮我做推广,南昌抖音推广公司,网站制作 手机,如何做英文网站的中文网互斥量#xff08;Mutex#xff09;
互斥量又称互斥信号量#xff08;本质也是一种信号量#xff0c;不具备传递数据功能#xff09;#xff0c;是一种特殊的二值信号量#xff0c;它和信号量不同的是#xff0c;它支持互斥量所有权、递归访问以及防止优先级翻转的特性…互斥量Mutex
互斥量又称互斥信号量本质也是一种信号量不具备传递数据功能是一种特殊的二值信号量它和信号量不同的是它支持互斥量所有权、递归访问以及防止优先级翻转的特性。比如有两个任务A在运行B就运行不了。
实验创建三个任务从高到低设置优先级在任务一和三中使用互斥量观察执行顺序。
实现在【STM32】FreeRTOS消息队列和信号量学习基础上进行修改 void MX_FREERTOS_Init(void) {/* USER CODE BEGIN Init *//* USER CODE END Init *//* Create the mutex(es) *//* definition and creation of Mutex01 */osMutexDef(Mutex01);Mutex01Handle osMutexCreate(osMutex(Mutex01));/* USER CODE BEGIN RTOS_MUTEX *//* add mutexes, ... *//* USER CODE END RTOS_MUTEX *//* Create the semaphores(s) *//* USER CODE BEGIN RTOS_SEMAPHORES *//* add semaphores, ... *//* USER CODE END RTOS_SEMAPHORES *//* USER CODE BEGIN RTOS_TIMERS *//* start timers, add new ones, ... *//* USER CODE END RTOS_TIMERS *//* USER CODE BEGIN RTOS_QUEUES *//* add queues, ... *//* USER CODE END RTOS_QUEUES *//* Create the thread(s) *//* definition and creation of Task1 */osThreadDef(Task1, StartDefaultTask, osPriorityHigh, 0, 128);Task1Handle osThreadCreate(osThread(Task1), NULL);/* definition and creation of Task2 */osThreadDef(Task2, StartTask02, osPriorityAboveNormal, 0, 128);Task2Handle osThreadCreate(osThread(Task2), NULL);/* definition and creation of Task3 */osThreadDef(Task3, StartTask03, osPriorityNormal, 0, 128);Task3Handle osThreadCreate(osThread(Task3), NULL);/* USER CODE BEGIN RTOS_THREADS *//* add threads, ... *//* USER CODE END RTOS_THREADS */}/* USER CODE BEGIN Header_StartDefaultTask */
/*** brief Function implementing the Task1 thread.* param argument: Not used* retval None*/
/* USER CODE END Header_StartDefaultTask */
void StartDefaultTask(void const * argument)
{/* USER CODE BEGIN StartDefaultTask *//* Infinite loop */for(;;){osDelay(10);//堵塞if(xSemaphoreTake(Mutex01Handle,portMAX_DELAY)!pdTRUE){printf(task1,进不去\r\n);}else{printf(task1,抢占进入\r\n);}xSemaphoreGive(Mutex01Handle);printf(task1,完成\r\n);}/* USER CODE END StartDefaultTask */
}/* USER CODE BEGIN Header_StartTask02 */
/**
* brief Function implementing the Task2 thread.
* param argument: Not used
* retval None
*/
/* USER CODE END Header_StartTask02 */
void StartTask02(void const * argument)
{/* USER CODE BEGIN StartTask02 *//* Infinite loop */for(;;){osDelay(2);//堵塞printf(task2运行\r\n);}/* USER CODE END StartTask02 */
}/* USER CODE BEGIN Header_StartTask03 */
/**
* brief Function implementing the Task3 thread.
* param argument: Not used
* retval None
*/
/* USER CODE END Header_StartTask03 */
void StartTask03(void const * argument)
{/* USER CODE BEGIN StartTask03 *//* Infinite loop */for(;;){xSemaphoreTake(Mutex01Handle,0);printf(task3,进入\r\n);xSemaphoreGive(Mutex01Handle);printf(task3,完成\r\n);}/* USER CODE END StartTask03 */
} 现象 最低优先级先执行最高优先级其次执行最后是中间优先级执行。
