Inter-Thread Communication using message queue
In this article we will develop an application for demonstrating Inter-Thread Communication between tasks/threads using message queue. Message passing is another basic communication model between threads. In the message passing model, one thread sends data explicitly, while another thread receives it.
The operation is more like some kind of I/O rather than a direct access to information to be shared.In CMSIS-RTOS, this mechanism is called s message queue. The data is passed from one thread to another in a FIFO-like operation. Using message queue functions, you can control, send, receive, or wait for messages. The data to be passed can be of integer or pointer type.
The embedded C code for this demo application is shown below.
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @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 "main.h"
#include <stdio.h>
#include <string.h>
#include "cmsis_os.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* 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 ---------------------------------------------------------*/
UART_HandleTypeDef huart6;
osThreadId Receiver_TaskHandle;
osThreadId Sender_TaskHandle;
osMessageQId myQueue1Handle;
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART6_UART_Init(void);
void Start_Receiver_Task(void const * argument);
void Start_Sender_Task(void const * argument);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_USART6_UART_Init();
/* USER CODE BEGIN 2 */
HAL_UART_Transmit(&huart6,(uint8_t*)"CMSIS_RTOS_MESSAGE_QUEUE\r\n",sizeof("CMSIS_RTOS_MESSAGE_QUEUE\r\n"),HAL_MAX_DELAY);
/* USER CODE END 2 */
/* USER CODE BEGIN RTOS_MUTEX */
/* add mutexes, ... */
/* USER CODE END RTOS_MUTEX */
/* 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 */
/* Create the queue(s) */
/* definition and creation of myQueue1 */
osMessageQDef(myQueue1, 16, uint16_t);
myQueue1Handle = osMessageCreate(osMessageQ(myQueue1), NULL);
/* USER CODE BEGIN RTOS_QUEUES */
/* add queues, ... */
/* USER CODE END RTOS_QUEUES */
/* Create the thread(s) */
/* definition and creation of Receiver_Task */
osThreadDef(Receiver_Task, Start_Receiver_Task, osPriorityNormal, 0, 128);
Receiver_TaskHandle = osThreadCreate(osThread(Receiver_Task), NULL);
/* definition and creation of Sender_Task */
osThreadDef(Sender_Task, Start_Sender_Task, osPriorityNormal, 0, 128);
Sender_TaskHandle = osThreadCreate(osThread(Sender_Task), NULL);
/* USER CODE BEGIN RTOS_THREADS */
/* add threads, ... */
/* USER CODE END RTOS_THREADS */
/* Start scheduler */
osKernelStart();
/* We should never get here as control is now taken by the scheduler */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Configure the main internal regulator output voltage
*/
__HAL_RCC_PWR_CLK_ENABLE();
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
领英推荐
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief USART6 Initialization Function
* @param None
* @retval None
*/
static void MX_USART6_UART_Init(void)
{
/* USER CODE BEGIN USART6_Init 0 */
/* USER CODE END USART6_Init 0 */
/* USER CODE BEGIN USART6_Init 1 */
/* USER CODE END USART6_Init 1 */
huart6.Instance = USART6;
huart6.Init.BaudRate = 9600;
huart6.Init.WordLength = UART_WORDLENGTH_8B;
huart6.Init.StopBits = UART_STOPBITS_1;
huart6.Init.Parity = UART_PARITY_NONE;
huart6.Init.Mode = UART_MODE_TX;
huart6.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart6.Init.OverSampling = UART_OVERSAMPLING_16;
if (HAL_UART_Init(&huart6) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN USART6_Init 2 */
/* USER CODE END USART6_Init 2 */
}
/**
* @brief GPIO Initialization Function
* @param None
* @retval None
*/
static void MX_GPIO_Init(void)
{
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
/* USER CODE BEGIN Header_Start_Receiver_Task */
/**
* @brief Function implementing the Receiver_Task thread.
* @param argument: Not used
* @retval None
*/
/* USER CODE END Header_Start_Receiver_Task */
void Start_Receiver_Task(void const * argument)
{
/* USER CODE BEGIN 5 */
osEvent event;
uint32_t data_value;
uint8_t data_value_string[20];
/* Infinite loop */
for(;;)
{
event = osMessageGet(myQueue1Handle, osWaitForever); // wait for message
if (event.status == osEventMessage) {
{
data_value = event.value.v;//Received message
sprintf((char*)data_value_string,"Data received is %lu",data_value);//convert uint32_t to string
strcat((char*)data_value_string,(const char*)("\r\n"));//concatenating string
HAL_UART_Transmit(&huart6,(uint8_t*)data_value_string,strlen((const char*)data_value_string),HAL_MAX_DELAY);
}
}
osDelay(1000);
}
/* USER CODE END 5 */
}
/* USER CODE BEGIN Header_Start_Sender_Task */
/**
* @brief Function implementing the Sender_Task thread.
* @param argument: Not used
* @retval None
*/
/* USER CODE END Header_Start_Sender_Task */
void Start_Sender_Task(void const * argument)
{
/* USER CODE BEGIN Start_Sender_Task */
uint32_t data = 6;
/* Infinite loop */
for(;;)
{
osMessagePut(myQueue1Handle,data, osWaitForever); // Send Message
}
/* USER CODE END Start_Sender_Task */
}
/**
* @brief Period elapsed callback in non blocking mode
* @note This function is called when TIM1 interrupt took place, inside
* HAL_TIM_IRQHandler(). It makes a direct call to HAL_IncTick() to increment
* a global variable "uwTick" used as application time base.
* @param htim : TIM handle
* @retval None
*/
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
/* USER CODE BEGIN Callback 0 */
/* USER CODE END Callback 0 */
if (htim->Instance == TIM1) {
HAL_IncTick();
}
/* USER CODE BEGIN Callback 1 */
/* USER CODE END Callback 1 */
}
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
Development Environment - STM32CubeIDE
Development kit - STM32401VC Discovery Kit
Programming Language - Embedded C
RTOS - CMSIS RTOS V1
Bluetooth Speaker Researcher
11 个月Please comment if you want to suggest something.