FreeRTOS篇9:计数型信号量
一.什么是计数型信号量?
计数型信号量相当于队列长度大于1 的队列,因此计数型信号量能够容纳多个资源,这在计数型 信号量被创建的时候确定的。
二.计数型信号量相关 API 函数
计数型信号量的释放和获取与二值信号量完全相同 !
参数:
uxMaxCount:可以达到的最大计数值 uxInitialCount:创建信号量时分配给信号量的计数值
返回值:
成功,返回对应计数型信号量的句柄; 失败,返回 NULL 。
三.实操
1.实验需求
创建一个计数型信号量,按下 KEY1 则释放信号量,按下 KEY2 获取信号量。
2.cubeMX配置
将 Config parameters 标签里的 USE_COUNTING_SEMAPHORES 设置为 Enabled 。
3.代码实现
/* USER CODE BEGIN Header */
/**
******************************************************************************
* File Name : freertos.c
* Description : Code for freertos applications
******************************************************************************
* @attention
*
* Copyright (c) 2024 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "FreeRTOS.h"
#include "task.h"
#include "main.h"
#include "cmsis_os.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <stdio.h>
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN Variables */
/* USER CODE END Variables */
osThreadId taskGiveHandle;
osThreadId taskTakeHandle;
osSemaphoreId myCountingSemHandle;
/* Private function prototypes -----------------------------------------------*/
/* USER CODE BEGIN FunctionPrototypes */
/* USER CODE END FunctionPrototypes */
void StartTaskGive(void const * argument);
void StartTaskTake(void const * argument);
void MX_FREERTOS_Init(void); /* (MISRA C 2004 rule 8.1) */
/* GetIdleTaskMemory prototype (linked to static allocation support) */
void vApplicationGetIdleTaskMemory( StaticTask_t **ppxIdleTaskTCBBuffer, StackType_t **ppxIdleTaskStackBuffer, uint32_t *pulIdleTaskStackSize );
/* USER CODE BEGIN GET_IDLE_TASK_MEMORY */
static StaticTask_t xIdleTaskTCBBuffer;
static StackType_t xIdleStack[configMINIMAL_STACK_SIZE];
void vApplicationGetIdleTaskMemory( StaticTask_t **ppxIdleTaskTCBBuffer, StackType_t **ppxIdleTaskStackBuffer, uint32_t *pulIdleTaskStackSize )
{
*ppxIdleTaskTCBBuffer = &xIdleTaskTCBBuffer;
*ppxIdleTaskStackBuffer = &xIdleStack[0];
*pulIdleTaskStackSize = configMINIMAL_STACK_SIZE;
/* place for user code */
}
/* USER CODE END GET_IDLE_TASK_MEMORY */
/**
* @brief FreeRTOS initialization
* @param None
* @retval None
*/
void MX_FREERTOS_Init(void) {
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* USER CODE BEGIN RTOS_MUTEX */
/* add mutexes, ... */
/* USER CODE END RTOS_MUTEX */
/* Create the semaphores(s) */
/* definition and creation of myCountingSem */
// osSemaphoreDef(myCountingSem);
// myCountingSemHandle = osSemaphoreCreate(osSemaphore(myCountingSem), 3);
myCountingSemHandle =xSemaphoreCreateCounting(3,0);
/* 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 taskGive */
osThreadDef(taskGive, StartTaskGive, osPriorityNormal, 0, 128);
taskGiveHandle = osThreadCreate(osThread(taskGive), NULL);
/* definition and creation of taskTake */
osThreadDef(taskTake, StartTaskTake, osPriorityNormal, 0, 128);
taskTakeHandle = osThreadCreate(osThread(taskTake), NULL);
/* USER CODE BEGIN RTOS_THREADS */
/* add threads, ... */
/* USER CODE END RTOS_THREADS */
}
/* USER CODE BEGIN Header_StartTaskGive */
/**
* @brief Function implementing the taskGive thread.
* @param argument: Not used
* @retval None
*/
/* USER CODE END Header_StartTaskGive */
void StartTaskGive(void const * argument)
{
/* USER CODE BEGIN StartTaskGive */
/* Infinite loop */
for(;;)
{
if(HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_0)==GPIO_PIN_RESET)
{
osDelay(20);
if(HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_0)==GPIO_PIN_RESET)
{
if(xSemaphoreGive(myCountingSemHandle)==pdTRUE)
printf("计数型信号量放入成功\r\n");
else
printf("计数型信号量放入失败\r\n");
}
while(HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_0)==GPIO_PIN_RESET);
}
osDelay(10);
}
/* USER CODE END StartTaskGive */
}
/* USER CODE BEGIN Header_StartTaskTake */
/**
* @brief Function implementing the taskTake thread.
* @param argument: Not used
* @retval None
*/
/* USER CODE END Header_StartTaskTake */
void StartTaskTake(void const * argument)
{
/* USER CODE BEGIN StartTaskTake */
/* Infinite loop */
for(;;)
{
if(HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_1)==GPIO_PIN_RESET)
{
osDelay(20);
if(HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_1)==GPIO_PIN_RESET)
{
if(xSemaphoreTake(myCountingSemHandle,0)==pdTRUE)
printf("计数型信号量放入成功\r\n");
else
printf("计数型信号量放入失败\r\n");
}
while(HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_1)==GPIO_PIN_RESET);
}
osDelay(10);
}
/* USER CODE END StartTaskTake */
}
/* Private application code --------------------------------------------------*/
/* USER CODE BEGIN Application */
/* USER CODE END Application */
原文地址:https://blog.csdn.net/2401_83811921/article/details/142689956
免责声明:本站文章内容转载自网络资源,如本站内容侵犯了原著者的合法权益,可联系本站删除。更多内容请关注自学内容网(zxcms.com)!