#ifndef FIXEDSLOTSEQUENCE_H_ #define FIXEDSLOTSEQUENCE_H_ #include #include #include /** * \brief This class is the representation of a Polling Sequence Table in software. * * \details The FixedSlotSequence object maintains the dynamic execution of device handler objects. * The main idea is to create a list of device handlers, to announce all handlers to the * polling sequence and to maintain a list of polling slot objects. This slot list represents the * Polling Sequence Table in software. Each polling slot contains information to indicate when and * which device handler shall be executed within a given polling period. * The sequence is then executed by iterating through this slot list. * Handlers are invoking by calling a certain function stored in the handler list. */ class FixedSlotSequence { public: /** * \brief The constructor of the FixedSlotSequence object. * * \details The constructor takes two arguments, the period length and the init function. * * \param setLength The period length, expressed in ms. */ FixedSlotSequence(uint32_t setLengthMs); /** * \brief The destructor of the FixedSlotSequence object. * * \details The destructor frees all allocated memory by iterating through the slotList * and deleting all allocated resources. */ virtual ~FixedSlotSequence(); /** * \brief This is a method to add an PollingSlot object to slotList. * * \details Here, a polling slot object is added to the slot list. It is appended * to the end of the list. The list is currently NOT reordered. * Afterwards, the iterator current is set to the beginning of the list. */ void addSlot(object_id_t handlerId, uint32_t setTime, int8_t setSequenceId, PeriodicTaskIF* executingTask); /** * Checks if the current slot shall be executed immediately after the one before. * This allows to distinguish between grouped and not grouped handlers. * @return - @c true if the slot has the same polling time as the previous * - @c false else */ bool slotFollowsImmediately(); /** * \brief This method returns the time until the next software component is invoked. * * \details This method is vitally important for the operation of the PST. By fetching the polling time * of the current slot and that of the next one (or the first one, if the list end is reached) * it calculates and returns the interval in clock ticks within which the handler execution * shall take place. */ uint32_t getIntervalMs(); /** * \brief This method returns the length of this FixedSlotSequence instance. */ uint32_t getLengthMs() const; /** * \brief The method to execute the device handler entered in the current OPUSPollingSlot object. * * \details Within this method the device handler object to be executed is chosen by looking up the * handler address of the current slot in the handlerMap. Either the device handler's * talkToInterface or its listenToInterface method is invoked, depending on the isTalking flag * of the polling slot. After execution the iterator current is increased or, by reaching the * end of slotList, reset to the beginning. */ void executeAndAdvance(); /** * \brief An iterator that indicates the current polling slot to execute. * * \details This is an iterator for slotList and always points to the polling slot which is executed next. */ std::list::iterator current; ReturnValue_t checkSequence() const; protected: /** * \brief This list contains all OPUSPollingSlot objects, defining order and execution time of the * device handler objects. * * \details The slot list is a std:list object that contains all created OPUSPollingSlot instances. * They are NOT ordered automatically, so by adding entries, the correct order needs to be ensured. * By iterating through this list the polling sequence is executed. Two entries with identical * polling times are executed immediately one after another. */ std::list slotList; uint32_t lengthMs; }; #endif /* FIXEDSLOTSEQUENCE_H_ */