pleslie76 wrote on Wednesday, October 17, 2018:
I am having an issue with a project where the scheduler wont call tasks or the tasks are always in blocking state. Below is code and information. I am trying to learn RTOS and can’t figure out the issue. I am using FreeRTOS 10.1. Also if I remove all of the semaphore code the project works as desired and all the LED blink of and on. It only fails with the semaphore code added.
This project is being used on a STM32F407 Discovery board.
main.c
#include "stm32f4xx_hal.h" // Keil::Device:STM32Cube HAL:Common
#include "FreeRTOS.h" // ARM.FreeRTOS::RTOS:Core
#include "task.h" // FreeRTOS task header
#include "leds.h" // LED control header file
#include "semphr.h" // ARM.FreeRTOS::RTOS:Core
xSemaphoreHandle gatekeeper = 0;
void vGreenLedControlTask(void *pvParameters);
void vRedLedControlTask(void *pvParameters);
void vBlueLedControlTask(void *pvParameters);
void vOrangeLedControlTask(void *pvParameters);
int main()
{
printf("starting Main(0)\n");
printf("initialize Leds\n");
LEDs_Init();
printf("Creante Queue Handle\n");
gatekeeper = xSemaphoreCreateMutex();
printf("Creating Tasks\n");
xTaskCreate(vBlueLedControlTask,
"Blue LED Controller",
1024,
NULL,
1,
NULL);
xTaskCreate(vRedLedControlTask,
"Red LED Controller",
1024,
NULL,
2,
NULL);
xTaskCreate(vOrangeLedControlTask,
"Orange LED Controller",
1024,
NULL,
3,
NULL);
xTaskCreate(vGreenLedControlTask,
"Green LED Controller",
1024,
NULL,
4,
NULL);
printf("Starting Task Scheduler\n");
vTaskStartScheduler();
printf("Task Scheduler started\n");
while(1){}
}
void vGreenLedControlTask(void *pvParameters)
{
printf("Entering Green\n");
while(1)
{
if(xSemaphoreTake(gatekeeper, 2500))
{
GREEN_toggle();
xSemaphoreGive(gatekeeper);
vTaskDelay(500);
}
else{
printf("Green did not get the semaphore\n");
}
}
}
void vBlueLedControlTask(void *pvParameters)
{
printf("Entering Blue\n");
while(1)
{
if(xSemaphoreTake(gatekeeper, 2500))
{
BLUE_toggle();
xSemaphoreGive(gatekeeper);
vTaskDelay(2000);
}
else{
printf("Blue did not receive semaphore\n");
}
}
}
void vRedLedControlTask(void *pvParameters)
{
while(1)
{
printf("Entering Red\n");
if(xSemaphoreTake(gatekeeper, 2500))
{
RED_toggle();
xSemaphoreGive(gatekeeper);
vTaskDelay(1500);
}
else{
printf("Red did not get the semaphore\n");
}
}
}
void vOrangeLedControlTask(void *pvParameters)
{
printf("Entering Orange\n");
while(1)
{
if(xSemaphoreTake(gatekeeper, 2500))
{
ORANGE_toggle();
xSemaphoreGive(gatekeeper);
vTaskDelay(1000);
}
else{
printf("Orange did not get the semaphore\n");
}
}
}
FreeRTOSConfig.h
#ifndef FREERTOS_CONFIG_H
#define FREERTOS_CONFIG_H
/*-----------------------------------------------------------
* Application specific definitions.
*
* These definitions should be adjusted for your particular hardware and
* application requirements.
*
* THESE PARAMETERS ARE DESCRIBED WITHIN THE 'CONFIGURATION' SECTION OF THE
* FreeRTOS API DOCUMENTATION AVAILABLE ON THE FreeRTOS.org WEB SITE.
*
* See http://www.freertos.org/a00110.html.
*----------------------------------------------------------*/
#include <stdint.h>
extern uint32_t SystemCoreClock;
#define configCPU_CLOCK_HZ (SystemCoreClock)
#define configTICK_RATE_HZ ((TickType_t)1000)
#define configTOTAL_HEAP_SIZE ((size_t)(4096))
#define configMINIMAL_STACK_SIZE ((unsigned short)130)
#define configCHECK_FOR_STACK_OVERFLOW 0
#define configMAX_PRIORITIES (5)
#define configUSE_PREEMPTION 1
#define configIDLE_SHOULD_YIELD 1
#define configMAX_TASK_NAME_LEN (10)
/* Software timer definitions. */
#define configUSE_TIMERS 1
#define configTIMER_TASK_PRIORITY (2)
#define configTIMER_QUEUE_LENGTH 5
#define configTIMER_TASK_STACK_DEPTH (configMINIMAL_STACK_SIZE * 2)
#define configUSE_MUTEXES 1
#define configUSE_RECURSIVE_MUTEXES 1
#define configUSE_COUNTING_SEMAPHORES 1
#define configUSE_QUEUE_SETS 1
#define configUSE_IDLE_HOOK 0
#define configUSE_TICK_HOOK 0
#define configUSE_MALLOC_FAILED_HOOK 0
#define configUSE_16_BIT_TICKS 0
/* Set the following definitions to 1 to include the API function, or zero
to exclude the API function. */
#define INCLUDE_vTaskPrioritySet 1
#define INCLUDE_uxTaskPriorityGet 1
#define INCLUDE_vTaskDelete 1
#define INCLUDE_vTaskSuspend 1
#define INCLUDE_vTaskDelayUntil 1
#define INCLUDE_vTaskDelay 1
#define INCLUDE_eTaskGetState 1
/* Cortex-M specific definitions. */
#ifdef __NVIC_PRIO_BITS
/* __BVIC_PRIO_BITS will be specified when CMSIS is being used. */
#define configPRIO_BITS __NVIC_PRIO_BITS
#else
/* 15 priority levels */
#define configPRIO_BITS 4
#endif
/* The lowest interrupt priority that can be used in a call to a "set priority"
function. */
#define configLIBRARY_LOWEST_INTERRUPT_PRIORITY 0xff
/* The highest interrupt priority that can be used by any interrupt service
routine that makes calls to interrupt safe FreeRTOS API functions. DO NOT CALL
INTERRUPT SAFE FREERTOS API FUNCTIONS FROM ANY INTERRUPT THAT HAS A HIGHER
PRIORITY THAN THIS! (higher priorities are lower numeric values. */
#define configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY 10
/* Interrupt priorities used by the kernel port layer itself. These are generic
to all Cortex-M ports, and do not rely on any particular library functions. */
#define configKERNEL_INTERRUPT_PRIORITY (configLIBRARY_LOWEST_INTERRUPT_PRIORITY << (8 - configPRIO_BITS))
/* !!!! configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to zero !!!!
See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html. */
#define configMAX_SYSCALL_INTERRUPT_PRIORITY (configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY << (8 - configPRIO_BITS))
/* Normal assert() semantics without relying on the provision of an assert.h
header file. */
#define configASSERT( x ) if( ( x ) == 0 ) { taskDISABLE_INTERRUPTS(); for( ;; ); }
/* Map the FreeRTOS port interrupt handlers to their CMSIS standard names. */
#define xPortPendSVHandler PendSV_Handler
#define vPortSVCHandler SVC_Handler
#define xPortSysTickHandler SysTick_Handler
/* Include debug event definitions */
#include "freertos_evr.h"
#endif /* FREERTOS_CONFIG_H */
Using Keil 5.25 the printf Debug viewer shows that the scheduler is started but no tasks ever execute.
from debug window:
starting Main() initialize Leds Create Semaphore Handle Creating Tasks Starting Task Scheduler
Please let me know what I am doing wrong.
loop of portTASK_FUNCTION. It keeps calling prvCheckTasksWaitingTermination() function. It then goes to a while loop while(uxDeleteTasksWaitingCleanup > ( UBaseType_t) 0U). It never goes into this while loop because taskswaitingcleanup is always 0. It then goes to this if statement if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( UBaseType_t ) 1 ) and then back to the prvCheckTasksWaitingTermination(). It does not enter the if statement.