Hi All,
I am running below application. There is a strange behaviour.
- HP task scheduled first, then above normal priority task is scheduled, then normal priority task is scheduled, then low priority task acquires the semaphore (mutex) but it is NOT scheduled. Instead, HP task is scheduled again even though mutex is not acquired by HP task. I have attached CAN message as output and also the code for your convenience.
Please note that, I check the value of x to make sure if LP task is ever scheduled or not. Obviously, when x leaves normal priority task having value of 3, it becomes 5 when HP task is scheduled, which indicates LP task is scheduled in which x is incremented by 1.
Thank you for any kind of support.
/* 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 "cmsis_os.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <string.h>
#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 ---------------------------------------------------------*/
CAN_HandleTypeDef hcan1;
UART_HandleTypeDef huart2;
osThreadId CAN1Handle;
osThreadId CAN2Handle;
osThreadId CAN3Handle;
osThreadId CAN4Handle;
osMutexId CANMutexHandle;
osSemaphoreId BinSemHandle;
/* USER CODE BEGIN PV */
CAN_TxHeaderTypeDef TxHeader;
uint8_t TxData[8];
uint32_t TxMailBox;
uint8_t x=0;
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);
static void MX_CAN1_Init(void);
void CanLowPriorityTask(void const * argument);
void CanNormalPriorityTask(void const * argument);
void CANAboveNormalPriorityTask(void const * argument);
void CANHighPriorityTask(void const * argument);
/* USER CODE BEGIN PFP */
void printmsg(char *msg);
void CAN_HP(void);
void CAN_LP(void);
void CAN_NP(void);
void CAN_ANP(void);
/* 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_USART2_UART_Init();
MX_CAN1_Init();
/* USER CODE BEGIN 2 */
HAL_CAN_Start(&hcan1);
/* USER CODE END 2 */
/* Create the mutex(es) */
/* definition and creation of CANMutex */
osMutexDef(CANMutex);
CANMutexHandle = osMutexCreate(osMutex(CANMutex));
/* USER CODE BEGIN RTOS_MUTEX */
/* add mutexes, ... */
/* USER CODE END RTOS_MUTEX */
/* Create the semaphores(s) */
/* definition and creation of BinSem */
osSemaphoreDef(BinSem);
BinSemHandle = osSemaphoreCreate(osSemaphore(BinSem), 1);
/* 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 CAN1 */
osThreadDef(CAN1, CanLowPriorityTask, osPriorityLow, 0, 128);
CAN1Handle = osThreadCreate(osThread(CAN1), NULL);
/* definition and creation of CAN2 */
osThreadDef(CAN2, CanNormalPriorityTask, osPriorityNormal, 0, 128);
CAN2Handle = osThreadCreate(osThread(CAN2), NULL);
/* definition and creation of CAN3 */
osThreadDef(CAN3, CANAboveNormalPriorityTask, osPriorityAboveNormal, 0, 128);
CAN3Handle = osThreadCreate(osThread(CAN3), NULL);
/* definition and creation of CAN4 */
osThreadDef(CAN4, CANHighPriorityTask, osPriorityHigh, 0, 128);
CAN4Handle = osThreadCreate(osThread(CAN4), 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_SCALE1);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 4;
RCC_OscInitStruct.PLL.PLLN = 168;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 7;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** 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_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief CAN1 Initialization Function
* @param None
* @retval None
*/
static void MX_CAN1_Init(void)
{
/* USER CODE BEGIN CAN1_Init 0 */
/* USER CODE END CAN1_Init 0 */
/* USER CODE BEGIN CAN1_Init 1 */
/* USER CODE END CAN1_Init 1 */
hcan1.Instance = CAN1;
hcan1.Init.Prescaler = 6;
hcan1.Init.Mode = CAN_MODE_LOOPBACK;
hcan1.Init.SyncJumpWidth = CAN_SJW_1TQ;
hcan1.Init.TimeSeg1 = CAN_BS1_11TQ;
hcan1.Init.TimeSeg2 = CAN_BS2_2TQ;
hcan1.Init.TimeTriggeredMode = DISABLE;
hcan1.Init.AutoBusOff = DISABLE;
hcan1.Init.AutoWakeUp = DISABLE;
hcan1.Init.AutoRetransmission = DISABLE;
hcan1.Init.ReceiveFifoLocked = DISABLE;
hcan1.Init.TransmitFifoPriority = DISABLE;
if (HAL_CAN_Init(&hcan1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN CAN1_Init 2 */
//configure CAN peripheral
CAN_FilterTypeDef FilterConfig;
FilterConfig.FilterBank = 10;
FilterConfig.FilterMode = CAN_FILTERMODE_IDMASK;
FilterConfig.FilterScale = CAN_FILTERSCALE_32BIT;
FilterConfig.FilterIdHigh = 0x18FD;
FilterConfig.FilterIdLow = 0xB7FE<<3;
FilterConfig.FilterMaskIdHigh = 0xFFFF;
FilterConfig.FilterMaskIdLow = 0xFFFF<<3;
FilterConfig.FilterFIFOAssignment = CAN_RX_FIFO0;
FilterConfig.FilterActivation = ENABLE;
FilterConfig.SlaveStartFilterBank = 14;
HAL_CAN_ConfigFilter(&hcan1, &FilterConfig);
/* USER CODE END CAN1_Init 2 */
}
/**
* @brief USART2 Initialization Function
* @param None
* @retval None
*/
static void MX_USART2_UART_Init(void)
{
/* USER CODE BEGIN USART2_Init 0 */
/* USER CODE END USART2_Init 0 */
/* USER CODE BEGIN USART2_Init 1 */
/* USER CODE END USART2_Init 1 */
huart2.Instance = USART2;
huart2.Init.BaudRate = 115200;
huart2.Init.WordLength = UART_WORDLENGTH_8B;
huart2.Init.StopBits = UART_STOPBITS_1;
huart2.Init.Parity = UART_PARITY_NONE;
huart2.Init.Mode = UART_MODE_TX_RX;
huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart2.Init.OverSampling = UART_OVERSAMPLING_16;
if (HAL_UART_Init(&huart2) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN USART2_Init 2 */
/* USER CODE END USART2_Init 2 */
}
/**
* @brief GPIO Initialization Function
* @param None
* @retval None
*/
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOH_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOD_CLK_ENABLE();
/*Configure GPIO pin : PA0 */
GPIO_InitStruct.Pin = GPIO_PIN_0;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}
/* USER CODE BEGIN 4 */
void printmsg( char *msg)
{
HAL_UART_Transmit(&huart2, (uint8_t*)msg,strlen(msg),1000);
}
void CAN_HP(void)
{
TxHeader.IDE = CAN_ID_EXT;
TxHeader.ExtId = 0x18FDB7FE;
TxHeader.RTR = CAN_RTR_DATA ;
TxHeader.DLC = 8;
TxData[0]=x;
TxData[1]=0x2A;
TxData[2]=0x30;
TxData[3]=0x4A;
TxData[4]=0x50;
TxData[5]=0x6A;
TxData[6]=0x70;
TxData[7]=0x8A;
HAL_CAN_AddTxMessage(&hcan1, &TxHeader, TxData, &TxMailBox);
}
void CAN_ANP(void)
{
TxHeader.IDE = CAN_ID_EXT;
TxHeader.ExtId = 0x18FDB7FE;
TxHeader.RTR = CAN_RTR_DATA ;
TxHeader.DLC = 8;
TxData[0]=x;
TxData[1]=0xA2;
TxData[2]=0x53;
TxData[3]=0xA4;
TxData[4]=0x55;
TxData[5]=0xA6;
TxData[6]=0x57;
TxData[7]=0xA8;
HAL_CAN_AddTxMessage(&hcan1, &TxHeader, TxData, &TxMailBox);
}
void CAN_NP(void)
{
TxHeader.IDE = CAN_ID_EXT;
TxHeader.ExtId = 0x18FDB7FE;
TxHeader.RTR = CAN_RTR_DATA ;
TxHeader.DLC = 8;
TxData[0]=x;
TxData[1]=0xA8;
TxData[2]=0x57;
TxData[3]=0xA6;
TxData[4]=0x10;
TxData[5]=0x2A;
TxData[6]=0x30;
TxData[7]=0x4A;
HAL_CAN_AddTxMessage(&hcan1, &TxHeader, TxData, &TxMailBox);
}
void CAN_LP(void)
{
TxHeader.IDE = CAN_ID_EXT;
TxHeader.ExtId = 0x18FDB7FE;
TxHeader.RTR = CAN_RTR_DATA ;
TxHeader.DLC = 8;
TxData[0]=x;
TxData[1]=0xA6;
TxData[2]=0x30;
TxData[3]=0xA6;
TxData[4]=0x20;
TxData[5]=0xA6;
TxData[6]=0x52;
TxData[7]=0xA0;
HAL_CAN_AddTxMessage(&hcan1, &TxHeader, TxData, &TxMailBox);
}
/* USER CODE END 4 */
/* USER CODE BEGIN Header_CanLowPriorityTask */
/**
* @brief Function implementing the CAN1 thread.
* @param argument: Not used
* @retval None
*/
/* USER CODE END Header_CanLowPriorityTask */
void CanLowPriorityTask(void const * argument)
{
/* USER CODE BEGIN 5 */
/* Infinite loop */
for(;;)
{
osMutexWait(CANMutexHandle, osWaitForever);
/*char *str1="entered low priority CAN task\n\r";
printmsg(str1);
char *str2 = "semaphore acquired by CAN Low task\n\r";
printmsg(str2);*/
x+=1;
CAN_LP();
osMutexRelease(CANMutexHandle);
//char *str3 = "leaving low priority CAN task\n\r";
//printmsg(str3);
osDelay(50);
}
/* USER CODE END 5 */
}
/* USER CODE BEGIN Header_CanNormalPriorityTask */
/**
* @brief Function implementing the CAN2 thread.
* @param argument: Not used
* @retval None
*/
/* USER CODE END Header_CanNormalPriorityTask */
void CanNormalPriorityTask(void const * argument)
{
/* USER CODE BEGIN CanNormalPriorityTask */
/* Infinite loop */
for(;;)
{
osMutexWait(CANMutexHandle, osWaitForever);
/*char *str1="entered normal priority CAN task\n\r";
printmsg(str1);
char *str2 = "semaphore acquired by CAN High task\n\r";
printmsg(str2);*/
x+=1;
CAN_NP();
osMutexRelease(CANMutexHandle);
// char *str3 = "leaving normal priority CAN task\n\r";
//printmsg(str3);
osDelay(50);
}
/* USER CODE END CanNormalPriorityTask */
}
/* USER CODE BEGIN Header_CANAboveNormalPriorityTask */
/**
* @brief Function implementing the CAN3 thread.
* @param argument: Not used
* @retval None
*/
/* USER CODE END Header_CANAboveNormalPriorityTask */
void CANAboveNormalPriorityTask(void const * argument)
{
/* USER CODE BEGIN CANAboveNormalPriorityTask */
/* Infinite loop */
for(;;)
{
osMutexWait(CANMutexHandle, osWaitForever);
/*char *str1="entered above normal priority CAN task\n\r";
printmsg(str1);
char *str2 = "semaphore acquired by CAN High task\n\r";
printmsg(str2);*/
x+=1;
CAN_ANP();
osMutexRelease(CANMutexHandle);
// char *str3 = "leaving above normal priority CAN task\n\r";
//printmsg(str3);
osDelay(50);
}
/* USER CODE END CANAboveNormalPriorityTask */
}
/* USER CODE BEGIN Header_CANHighPriorityTask */
/**
* @brief Function implementing the CAN4 thread.
* @param argument: Not used
* @retval None
*/
/* USER CODE END Header_CANHighPriorityTask */
void CANHighPriorityTask(void const * argument)
{
/* USER CODE BEGIN CANHighPriorityTask */
/* Infinite loop */
for(;;)
{
osMutexWait(CANMutexHandle, osWaitForever);
/*char *str1="entered high priority CAN task\n\r";
printmsg(str1);
char *str2 = "semaphore acquired by CAN High task\n\r";
printmsg(str2);*/
x+=1;
CAN_HP();
osMutexRelease(CANMutexHandle);
//char *str3 = "leaving high priority CAN task\n\r";
//printmsg(str3);
osDelay(50);
}
/* USER CODE END CANHighPriorityTask */
}
/**
* @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 */