diff --git a/osal/FreeRTOS/FixedTimeslotTask.cpp b/osal/FreeRTOS/FixedTimeslotTask.cpp index eea2f7d86..c062101d9 100644 --- a/osal/FreeRTOS/FixedTimeslotTask.cpp +++ b/osal/FreeRTOS/FixedTimeslotTask.cpp @@ -1,6 +1,7 @@ -#include #include "FixedTimeslotTask.h" +#include + uint32_t FixedTimeslotTask::deadlineMissedCount = 0; const size_t PeriodicTaskIF::MINIMUM_STACK_SIZE = configMINIMAL_STACK_SIZE; @@ -18,16 +19,19 @@ FixedTimeslotTask::~FixedTimeslotTask() { void FixedTimeslotTask::taskEntryPoint(void* argument) { - //The argument is re-interpreted as FixedTimeslotTask. The Task object is global, so it is found from any place. + // The argument is re-interpreted as FixedTimeslotTask. The Task object is + // global, so it is found from any place. FixedTimeslotTask *originalTask(reinterpret_cast(argument)); - // Task should not start until explicitly requested - // in FreeRTOS, tasks start as soon as they are created if the scheduler is running - // but not if the scheduler is not running. - // to be able to accommodate both cases we check a member which is set in #startTask() - // if it is not set and we get here, the scheduler was started before #startTask() was called and we need to suspend - // if it is set, the scheduler was not running before #startTask() was called and we can continue + /* Task should not start until explicitly requested, + * but in FreeRTOS, tasks start as soon as they are created if the scheduler + * is running but not if the scheduler is not running. + * To be able to accommodate both cases we check a member which is set in + * #startTask(). If it is not set and we get here, the scheduler was started + * before #startTask() was called and we need to suspend if it is set, + * the scheduler was not running before #startTask() was called and we + * can continue */ - if (!originalTask->started) { + if (not originalTask->started) { vTaskSuspend(NULL); } @@ -58,11 +62,6 @@ ReturnValue_t FixedTimeslotTask::startTask() { ReturnValue_t FixedTimeslotTask::addSlot(object_id_t componentId, uint32_t slotTimeMs, int8_t executionStep) { if (objectManager->get(componentId) != nullptr) { - if(slotTimeMs == 0) { - // FreeRTOS throws a sanity error for zero values, so we set - // the time to one millisecond. - slotTimeMs = 1; - } pst.addSlot(componentId, slotTimeMs, executionStep, this); return HasReturnvaluesIF::RETURN_OK; } @@ -81,8 +80,9 @@ ReturnValue_t FixedTimeslotTask::checkSequence() const { } void FixedTimeslotTask::taskFunctionality() { - // A local iterator for the Polling Sequence Table is created to find the start time for the first entry. - auto slotListIter = pst.current; + // A local iterator for the Polling Sequence Table is created to find the + // start time for the first entry. + FixedSlotSequence::SlotListIter slotListIter = pst.current; //The start time for the first entry is read. uint32_t intervalMs = slotListIter->pollingTimeMs; @@ -90,32 +90,68 @@ void FixedTimeslotTask::taskFunctionality() { TickType_t xLastWakeTime; /* The xLastWakeTime variable needs to be initialized with the current tick - count. Note that this is the only time the variable is written to explicitly. - After this assignment, xLastWakeTime is updated automatically internally within - vTaskDelayUntil(). */ + count. Note that this is the only time the variable is written to + explicitly. After this assignment, xLastWakeTime is updated automatically + internally within vTaskDelayUntil(). */ xLastWakeTime = xTaskGetTickCount(); // wait for first entry's start time - vTaskDelayUntil(&xLastWakeTime, interval); + if(interval > 0) { + vTaskDelayUntil(&xLastWakeTime, interval); + } /* Enter the loop that defines the task behavior. */ for (;;) { //The component for this slot is executed and the next one is chosen. - this->pst.executeAndAdvance(); - if (pst.slotFollowsImmediately()) { - //Do nothing - } else { - // we need to wait before executing the current slot - //this gives us the time to wait: - intervalMs = this->pst.getIntervalToPreviousSlotMs(); - interval = pdMS_TO_TICKS(intervalMs); - vTaskDelayUntil(&xLastWakeTime, interval); - //TODO deadline missed check - } + this->pst.executeAndAdvance(); + if (not pst.slotFollowsImmediately()) { + // Get the interval till execution of the next slot. + intervalMs = this->pst.getIntervalToPreviousSlotMs(); + interval = pdMS_TO_TICKS(intervalMs); + checkMissedDeadline(xLastWakeTime, interval); + + // Wait for the interval. This exits immediately if a deadline was + // missed while also updating the last wake time. + vTaskDelayUntil(&xLastWakeTime, interval); + } } } +void FixedTimeslotTask::checkMissedDeadline(const TickType_t xLastWakeTime, + const TickType_t interval) { + /* Check whether deadline was missed while also taking overflows + * into account. Drawing this on paper with a timeline helps to understand + * it. */ + TickType_t currentTickCount = xTaskGetTickCount(); + TickType_t timeToWake = xLastWakeTime + interval; + // Tick count has overflown + if(currentTickCount < xLastWakeTime) { + // Time to wake has overflown as well. If the tick count + // is larger than the time to wake, a deadline was missed. + if(timeToWake < xLastWakeTime and + currentTickCount > timeToWake) { + handleMissedDeadline(); + } + } + // No tick count overflow. If the timeToWake has not overflown + // and the current tick count is larger than the time to wake, + // a deadline was missed. + else if(timeToWake > xLastWakeTime and currentTickCount > timeToWake) { + handleMissedDeadline(); + } +} + +void FixedTimeslotTask::handleMissedDeadline() { +#ifdef DEBUG + sif::warning << "FixedTimeslotTask: " << pcTaskGetName(NULL) << + " missed deadline!\n" << std::flush; +#endif + if(deadlineMissedFunc != nullptr) { + this->deadlineMissedFunc(); + } +} + ReturnValue_t FixedTimeslotTask::sleepFor(uint32_t ms) { vTaskDelay(pdMS_TO_TICKS(ms)); return HasReturnvaluesIF::RETURN_OK; diff --git a/osal/FreeRTOS/FixedTimeslotTask.h b/osal/FreeRTOS/FixedTimeslotTask.h index d20b8268b..66af0311b 100644 --- a/osal/FreeRTOS/FixedTimeslotTask.h +++ b/osal/FreeRTOS/FixedTimeslotTask.h @@ -1,26 +1,27 @@ -#ifndef POLLINGTASK_H_ -#define POLLINGTASK_H_ +#ifndef FRAMEWORK_OSAL_FREERTOS_FIXEDTIMESLOTTASK_H_ +#define FRAMEWORK_OSAL_FREERTOS_FIXEDTIMESLOTTASK_H_ #include #include #include -extern "C" { -#include "FreeRTOS.h" -#include "task.h" -} +#include +#include class FixedTimeslotTask: public FixedTimeslotTaskIF { public: + /** - * @brief The standard constructor of the class. - * - * @details This is the general constructor of the class. In addition to the TaskBase parameters, - * the following variables are passed: - * - * @param (*setDeadlineMissedFunc)() The function pointer to the deadline missed function that shall be assigned. - * - * @param getPst The object id of the completely initialized polling sequence. + * Keep in mind that you need to call before vTaskStartScheduler()! + * A lot of task parameters are set in "FreeRTOSConfig.h". + * @param name Name of the task, lenght limited by configMAX_TASK_NAME_LEN + * @param setPriority Number of priorities specified by + * configMAX_PRIORITIES. High taskPriority_ number means high priority. + * @param setStack Stack size in words (not bytes!). + * Lower limit specified by configMINIMAL_STACK_SIZE + * @param overallPeriod Period in seconds. + * @param setDeadlineMissedFunc Callback if a deadline was missed. + * @return Pointer to the newly created task. */ FixedTimeslotTask(const char *name, TaskPriority setPriority, TaskStackSize setStack, TaskPeriod overallPeriod, @@ -28,16 +29,18 @@ public: /** * @brief The destructor of the class. - * - * @details The destructor frees all heap memory that was allocated on thread initialization for the PST and - * the device handlers. This is done by calling the PST's destructor. + * @details + * The destructor frees all heap memory that was allocated on thread + * initialization for the PST and the device handlers. This is done by + * calling the PST's destructor. */ virtual ~FixedTimeslotTask(void); ReturnValue_t startTask(void); /** * This static function can be used as #deadlineMissedFunc. - * It counts missedDeadlines and prints the number of missed deadlines every 10th time. + * It counts missedDeadlines and prints the number of missed deadlines + * every 10th time. */ static void missedDeadlineCounter(); /** @@ -46,13 +49,14 @@ public: static uint32_t deadlineMissedCount; ReturnValue_t addSlot(object_id_t componentId, uint32_t slotTimeMs, - int8_t executionStep); + int8_t executionStep) override; - uint32_t getPeriodMs() const; + uint32_t getPeriodMs() const override; - ReturnValue_t checkSequence() const; + ReturnValue_t checkSequence() const override; + + ReturnValue_t sleepFor(uint32_t ms) override; - ReturnValue_t sleepFor(uint32_t ms); protected: bool started; TaskHandle_t handle; @@ -60,32 +64,35 @@ protected: FixedSlotSequence pst; /** - * @brief This attribute holds a function pointer that is executed when a deadline was missed. - * - * @details Another function may be announced to determine the actions to perform when a deadline was missed. - * Currently, only one function for missing any deadline is allowed. - * If not used, it shall be declared NULL. + * @brief This attribute holds a function pointer that is executed when + * a deadline was missed. + * @details + * Another function may be announced to determine the actions to perform + * when a deadline was missed. Currently, only one function for missing + * any deadline is allowed. If not used, it shall be declared NULL. */ void (*deadlineMissedFunc)(void); /** - * @brief This is the entry point in a new polling thread. - * - * @details This method, that is the generalOSAL::checkAndRestartPeriod( this->periodId, interval ); entry point in the new thread, is here set to generate - * and link the Polling Sequence Table to the thread object and start taskFunctionality() - * on success. If operation of the task is ended for some reason, - * the destructor is called to free allocated memory. + * @brief This is the entry point for a new task. + * @details + * This method starts the task by calling taskFunctionality(), as soon as + * all requirements (task scheduler has started and startTask() + * has been called) are met. */ static void taskEntryPoint(void* argument); /** * @brief This function holds the main functionality of the thread. - * - * - * @details Holding the main functionality of the task, this method is most important. - * It links the functionalities provided by FixedSlotSequence with the OS's System Calls - * to keep the timing of the periods. + * @details + * Core function holding the main functionality of the task + * It links the functionalities provided by FixedSlotSequence with the + * OS's System Calls to keep the timing of the periods. */ void taskFunctionality(void); + + void checkMissedDeadline(const TickType_t xLastWakeTime, + const TickType_t interval); + void handleMissedDeadline(); }; -#endif /* POLLINGTASK_H_ */ +#endif /* FRAMEWORK_OSAL_FREERTOS_FIXEDTIMESLOTTASK_H_ */