continued with hk data pool

added deadline missed check for fixed timeslot task,
improved doc for both periodic task and fixed timeslot task

datapool/DataSetBase.cpp

@@ -53,6 +53,10 @@ ReturnValue_t DataSetBase::read(uint32_t lockTimeout) {
 	return result;
 }
 
+uint16_t DataSetBase::getFillCount() const {
+    return fillCount;
+}
+
 ReturnValue_t DataSetBase::readVariable(uint16_t count) {
 	ReturnValue_t result = HasReturnvaluesIF::RETURN_OK;
 	// These checks are often performed by the respective

datapool/DataSetBase.h

@@ -101,6 +101,8 @@ public:
 	 */
 	virtual ReturnValue_t unlockDataPool() override;
 
+	virtual uint16_t getFillCount() const;
+
 	/* SerializeIF implementations */
 	virtual ReturnValue_t serialize(uint8_t** buffer, size_t* size,
 				const size_t maxSize, bool bigEndian) const override;

datapool/DataSetIF.h

@@ -43,6 +43,7 @@ public:
 	 */
 	virtual ReturnValue_t registerVariable(PoolVariableIF* variable) = 0;
 
+	virtual uint16_t getFillCount() const = 0;
 private:
 	/**
 	 * @brief 	Most underlying data structures will have a pool like structure