fsfw/devicehandlers/FixedSlotSequence.h

123 lines
4.9 KiB
C++

#ifndef FIXEDSLOTSEQUENCE_H_
#define FIXEDSLOTSEQUENCE_H_
#include <framework/devicehandlers/FixedSequenceSlot.h>
#include <framework/objectmanager/SystemObject.h>
#include <list>
/**
* \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 milliseconds within which the handler execution
* shall take place. If the next slot has the same time as the current one, it is ignored until
* a slot with different time or the end of the PST is found.
*/
uint32_t getIntervalToNextSlotMs();
/**
* \brief This method returns the time difference between the current slot and the previous slot
*
* \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 prevous one (or the last one, if the slot is the first one)
* it calculates and returns the interval in milliseconds that the handler execution shall be delayed.
*/
uint32_t getIntervalToPreviousSlotMs();
/**
* \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<FixedSequenceSlot*>::iterator current;
/**
* Iterate through slotList and check successful creation.
* Checks if timing is ok (must be ascending) and if all handlers were found.
* @return
*/
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<FixedSequenceSlot*> slotList;
uint32_t lengthMs;
};
#endif /* FIXEDSLOTSEQUENCE_H_ */