Refactored and sorted bitvector

Former-commit-id: 28ca00af50

src/builder/ExplicitDFTModelBuilder.cpp

@@ -13,11 +13,52 @@ namespace storm {
         ExplicitDFTModelBuilder<ValueType>::ModelComponents::ModelComponents() : transitionMatrix(), stateLabeling(), markovianStates(), exitRates(), choiceLabeling() {
             // Intentionally left empty.
         }
+        
+        template <typename ValueType>
+        ExplicitDFTModelBuilder<ValueType>::ExplicitDFTModelBuilder(storm::storage::DFT<ValueType> const& dft) : mDft(dft), mStates(((mDft.stateVectorSize() / 64) + 1) * 64, std::pow(2, mDft.nrBasicElements())) {
+            // stateSize is bound for size of bitvector
+            // 2^nrBE is upper bound for state space
+
+            // Find symmetries
+            // TODO activate
+            // Currently using hack to test
+            std::vector<std::vector<size_t>> symmetries;
+            std::vector<size_t> vecB;
+            std::vector<size_t> vecC;
+            std::vector<size_t> vecD;
+            if (false) {
+                for (size_t i = 0; i < mDft.nrElements(); ++i) {
+                    std::string name = mDft.getElement(i)->name();
+                    size_t id = mDft.getElement(i)->id();
+                    if (boost::starts_with(name, "B")) {
+                        vecB.push_back(id);
+                    } else if (boost::starts_with(name, "C")) {
+                        vecC.push_back(id);
+                    } else if (boost::starts_with(name, "D")) {
+                        vecD.push_back(id);
+                    }
+                }
+                symmetries.push_back(vecB);
+                symmetries.push_back(vecC);
+                symmetries.push_back(vecD);
+                std::cout << "Found the following symmetries:" << std::endl;
+                for (auto const& symmetry : symmetries) {
+                    for (auto const& elem : symmetry) {
+                        std::cout << elem << " -> ";
+                    }
+                    std::cout << std::endl;
+                }
+            } else {
+                vecB.push_back(mDft.getTopLevelIndex());
+            }
+            mStateGenerationInfo = std::make_shared<storm::storage::DFTStateGenerationInfo>(mDft.buildStateGenerationInfo(vecB, symmetries));
+        }
+
 
         template <typename ValueType>
         std::shared_ptr<storm::models::sparse::Model<ValueType>> ExplicitDFTModelBuilder<ValueType>::buildModel() {
             // Initialize
-            DFTStatePointer state = std::make_shared<storm::storage::DFTState<ValueType>>(mDft, newIndex++);
+            DFTStatePointer state = std::make_shared<storm::storage::DFTState<ValueType>>(mDft, *mStateGenerationInfo, newIndex++);
             mStates.findOrAdd(state->status(), state);
 
             std::queue<DFTStatePointer> stateQueue;

src/builder/ExplicitDFTModelBuilder.h

@@ -44,15 +44,13 @@ namespace storm {
                 boost::optional<std::vector<boost::container::flat_set<uint_fast64_t>>> choiceLabeling;
             };
 
-            storm::storage::DFT<ValueType> const &mDft;
+            storm::storage::DFT<ValueType> const& mDft;
+            std::shared_ptr<storm::storage::DFTStateGenerationInfo> mStateGenerationInfo;
             storm::storage::BitVectorHashMap<DFTStatePointer> mStates;
             size_t newIndex = 0;
 
         public:
-            ExplicitDFTModelBuilder(storm::storage::DFT<ValueType> const &dft) : mDft(dft), mStates(((mDft.stateVectorSize() / 64) + 1) * 64, std::pow(2, mDft.nrBasicElements())) {
-                // stateSize is bound for size of bitvector
-                // 2^nrBE is upper bound for state space
-            }
+            ExplicitDFTModelBuilder(storm::storage::DFT<ValueType> const& dft);
 
             std::shared_ptr<storm::models::sparse::Model<ValueType>> buildModel();
 

src/storage/dft/DFT.cpp

@@ -10,15 +10,18 @@ namespace storm {
     namespace storage {
 
         template<typename ValueType>
-        DFT<ValueType>::DFT(DFTElementVector const& elements, DFTElementPointer const& tle) : mElements(elements), mTopLevelIndex(tle->id()), mNrOfBEs(0), mNrOfSpares(0)
-        {
+        DFT<ValueType>::DFT(DFTElementVector const& elements, DFTElementPointer const& tle) : mElements(elements), mNrOfBEs(0), mNrOfSpares(0), mTopLevelIndex(tle->id()) {
             assert(elementIndicesCorrect());
-            mUsageInfoBits = storm::utility::math::uint64_log2(mElements.size()-1)+1;
-            size_t stateIndex = 0;
+            size_t stateVectorIndex = 0;
+            std::set<size_t> tmpRepresentatives;
+            size_t usageInfoBits = storm::utility::math::uint64_log2(mElements.size()-1)+1;
+            size_t nrRepresentatives = 0;
             
             for (auto& elem : mElements) {
-                mIdToFailureIndex.push_back(stateIndex);
-                stateIndex += 2;
+                stateVectorIndex += 2;
+                if (isRepresentative(elem->id())) {
+                    ++nrRepresentatives;
+                }
                 if(elem->isBasicElement()) {
                     ++mNrOfBEs;
                 }
@@ -26,9 +29,7 @@ namespace storm {
                     ++mNrOfSpares;
                     bool firstChild = true;
                     for(auto const& spareReprs : std::static_pointer_cast<DFTSpare<ValueType>>(elem)->children()) {
-                        if(mActivationIndex.count(spareReprs->id()) == 0) {
-                            mActivationIndex[spareReprs->id()] =  stateIndex++;
-                        }
+                        tmpRepresentatives.insert(spareReprs->id());
                         std::set<size_t> module = {spareReprs->id()};
                         spareReprs->extendSpareModule(module);
                         std::vector<size_t> sparesAndBes;
@@ -44,14 +45,13 @@ namespace storm {
                         mSpareModules.insert(std::make_pair(spareReprs->id(), sparesAndBes));
                         firstChild = false;
                     }
-                    std::static_pointer_cast<DFTSpare<ValueType>>(elem)->setUseIndex(stateIndex);
-                    mUsageIndex.insert(std::make_pair(elem->id(), stateIndex));
-                    stateIndex += mUsageInfoBits;
+                    stateVectorIndex += usageInfoBits;
 
                 } else if (elem->isDependency()) {
                     mDependencies.push_back(elem->id());
                 }
             }
+            stateVectorIndex += tmpRepresentatives.size();
 
             // For the top module, we assume, contrary to [Jun15], that we have all spare gates and basic elements which are not in another module.
             std::set<size_t> topModuleSet;
@@ -68,12 +68,84 @@ namespace storm {
                 }
             }
             mTopModule = std::vector<size_t>(topModuleSet.begin(), topModuleSet.end());
-
-            mStateVectorSize = stateIndex;
+            
+            std::cout << tmpRepresentatives.size() << ", " << nrRepresentatives << std::endl;
+            std::cout << stateVectorIndex << ", " << (nrElements() * 2 + mNrOfSpares * usageInfoBits + tmpRepresentatives.size()) << std::endl;
+            assert(tmpRepresentatives.size() == nrRepresentatives);
+            assert(stateVectorIndex == nrElements() * 2 + mNrOfSpares * usageInfoBits + tmpRepresentatives.size());
+            mStateVectorSize = stateVectorIndex;
         }
 
+        template<typename ValueType>
+        DFTStateGenerationInfo DFT<ValueType>::buildStateGenerationInfo(std::vector<size_t> const& subTreeRoots, std::vector<std::vector<size_t>> const& symmetries) const {
+            // Use symmetry
+            // Collect all elements in the first subtree
+            // TODO make recursive to use for nested subtrees
+            
+            DFTStateGenerationInfo generationInfo(nrElements());
+
+            // Perform DFS and insert all elements of subtree sequentially
+            size_t stateIndex = 0;
+            std::queue<size_t> visitQueue;
+            std::set<size_t> visited;
+            visitQueue.push(subTreeRoots[0]);
+            bool consideredDependencies = false;
+            while (true) {
+                while (!visitQueue.empty()) {
+                    size_t id = visitQueue.front();
+                    visitQueue.pop();
+                    if (visited.count(id) == 1) {
+                        // Already visited
+                        continue;
+                    }
+                    visited.insert(id);
+                    DFTElementPointer element = mElements[id];
+                    
+                    // Insert children
+                    if (element->isGate()) {
+                        for (auto const& child : std::static_pointer_cast<DFTGate<ValueType>>(element)->children()) {
+                            visitQueue.push(child->id());
+                        }
+                    }
+                    
+                    // Reserve bits for element
+                    generationInfo.addStateIndex(id, stateIndex);
+                    stateIndex += 2;
+
+                    if (isRepresentative(id)) {
+                        generationInfo.addSpareActivationIndex(id, stateIndex);
+                        ++stateIndex;
+                    }
+
+                    if (element->isSpareGate()) {
+                        generationInfo.addSpareUsageIndex(id, stateIndex);
+                        stateIndex += generationInfo.usageInfoBits();
+                    }
+                    
+                }
+                
+                if (consideredDependencies) {
+                    break;
+                }
+                
+                // Consider dependencies
+                for (size_t idDependency : getDependencies()) {
+                    std::shared_ptr<DFTDependency<ValueType> const> dependency = getDependency(idDependency);
+                    visitQueue.push(dependency->id());
+                    visitQueue.push(dependency->triggerEvent()->id());
+                    visitQueue.push(dependency->dependentEvent()->id());
+                }
+                consideredDependencies = true;
+            }
+            assert(stateIndex = mStateVectorSize);
+
+            STORM_LOG_TRACE(generationInfo);
+            
+            return generationInfo;
         }
 
+
+
         template<typename ValueType>
         std::string DFT<ValueType>::getElementsString() const {
             std::stringstream stream;

src/storage/dft/DFT.h

@@ -33,6 +33,69 @@ namespace storm {
         // Forward declarations
         template<typename T> class DFTColouring;
 
+        
+        class DFTStateGenerationInfo {
+        private:
+            const size_t mUsageInfoBits;
+            std::map<size_t, size_t> mSpareUsageIndex; // id spare -> index first bit in state
+            std::map<size_t, size_t> mSpareActivationIndex; // id spare representative -> index in state
+            std::vector<size_t> mIdToStateIndex; // id -> index first bit in state
+            
+        public:
+            
+            DFTStateGenerationInfo(size_t nrElements) : mUsageInfoBits(storm::utility::math::uint64_log2(nrElements-1)+1), mIdToStateIndex(nrElements) {
+            }
+
+            size_t usageInfoBits() const {
+                return mUsageInfoBits;
+            }
+            
+            void addStateIndex(size_t id, size_t index) {
+                assert(id < mIdToStateIndex.size());
+                mIdToStateIndex[id] = index;
+            }
+
+            void addSpareActivationIndex(size_t id, size_t index) {
+                mSpareActivationIndex[id] = index;
+            }
+
+            void addSpareUsageIndex(size_t id, size_t index) {
+                mSpareUsageIndex[id] = index;
+            }
+
+            size_t getStateIndex(size_t id) const {
+                assert(id < mIdToStateIndex.size());
+                return mIdToStateIndex[id];
+            }
+            
+            size_t getSpareUsageIndex(size_t id) const {
+                assert(mSpareUsageIndex.count(id) > 0);
+                return mSpareUsageIndex.at(id);
+            }
+            
+            size_t getSpareActivationIndex(size_t id) const {
+                assert(mSpareActivationIndex.count(id) > 0);
+                return mSpareActivationIndex.at(id);
+            }
+            
+            friend std::ostream& operator<<(std::ostream& os, DFTStateGenerationInfo const& info) {
+                os << "Id to state index:" << std::endl;
+                for (size_t id = 0; id < info.mIdToStateIndex.size(); ++id) {
+                    os << id << " -> " << info.getStateIndex(id) << std::endl;
+                }
+                os << "Spare usage index with usage InfoBits of size " << info.mUsageInfoBits << ":" << std::endl;
+                for (auto pair : info.mSpareUsageIndex) {
+                    os << pair.first << " -> " << pair.second << std::endl;
+                }
+                os << "Spare activation index:" << std::endl;
+                for (auto pair : info.mSpareActivationIndex) {
+                    os << pair.first << " -> " << pair.second << std::endl;
+                }
+                return os;
+            }
+            
+        };
+        
 
         /**
          * Represents a Dynamic Fault Tree
@@ -52,18 +115,17 @@ namespace storm {
             size_t mNrOfBEs;
             size_t mNrOfSpares;
             size_t mTopLevelIndex;
-            size_t mUsageInfoBits;
             size_t mStateVectorSize;
-            std::map<size_t, size_t> mActivationIndex;
             std::map<size_t, std::vector<size_t>> mSpareModules;
             std::vector<size_t> mDependencies;
             std::vector<size_t> mTopModule;
-            std::vector<size_t> mIdToFailureIndex;
-            std::map<size_t, size_t> mUsageIndex;
-            std::map<size_t, size_t> mRepresentants;
+            std::map<size_t, size_t> mRepresentants; // id element -> id representative
+            std::vector<std::vector<size_t>> mSymmetries;
             
         public:
             DFT(DFTElementVector const& elements, DFTElementPointer const& tle);
+            
+            DFTStateGenerationInfo buildStateGenerationInfo(std::vector<size_t> const& subTreeRoots, std::vector<std::vector<size_t>> const& symmetries) const;
 
             size_t stateVectorSize() const {
                 return mStateVectorSize;
@@ -77,34 +139,8 @@ namespace storm {
                 return mNrOfBEs;
             }
             
-            size_t usageInfoBits() const {
-                return mUsageInfoBits;
-            }
-            
-            size_t usageIndex(size_t id) const {
-                assert(mUsageIndex.find(id) != mUsageIndex.end());
-                return mUsageIndex.find(id)->second;
-            }
-            
-            size_t failureIndex(size_t id) const {
-                return mIdToFailureIndex[id];
-            }
-            
-            void initializeUses(DFTState<ValueType>& state) const {
-                for(auto const& elem : mElements) {
-                    if(elem->isSpareGate()) {
-                        std::static_pointer_cast<DFTSpare<ValueType>>(elem)->initializeUses(state);
-                    }
-                }
-            }
-            
-            void initializeActivation(DFTState<ValueType>& state) const {
-                state.activate(mTopLevelIndex);
-                for(auto const& elem : mTopModule) {
-                    if(mElements[elem]->isSpareGate()) {
-                        propagateActivation(state, state.uses(elem));
-                    }
-                }
+            size_t getTopLevelIndex() const {
+                return mTopLevelIndex;
             }
             
             std::vector<size_t> getSpareIndices() const {
@@ -130,15 +166,6 @@ namespace storm {
                 return mDependencies;
             }
 
-            void propagateActivation(DFTState<ValueType>& state, size_t representativeId) const {
-                state.activate(representativeId);
-                for(size_t id : module(representativeId)) {
-                    if(mElements[id]->isSpareGate()) {
-                        propagateActivation(state, state.uses(id));
-                    }
-                }
-            }
-            
             std::vector<size_t> nonColdBEs() const {
                 std::vector<size_t> result;
                 for(DFTElementPointer elem : mElements) {
@@ -170,10 +197,6 @@ namespace storm {
                 return getElement(index)->isDependency();
             }
 
-//            std::shared_ptr<DFTGate<ValueType> const> getGate(size_t index) const {
-//                return
-//            }
-
             std::shared_ptr<DFTBE<ValueType> const> getBasicElement(size_t index) const {
                 assert(isBasicElement(index));
                 return std::static_pointer_cast<DFTBE<ValueType> const>(mElements[index]);

src/storage/dft/DFTElements.h

@@ -898,10 +898,6 @@ namespace storm {
         template<typename ValueType>
         class DFTSpare : public DFTGate<ValueType> {
 
-        private:
-            size_t mUseIndex;
-            size_t mActiveIndex;
-            
         public:
             DFTSpare(size_t id, std::string const& name, std::vector<std::shared_ptr<DFTElement<ValueType>>> const& children = {}) :
                     DFTGate<ValueType>(id, name, children)
@@ -919,24 +915,11 @@ namespace storm {
                 return true;
             }
             
-            void setUseIndex(size_t useIndex) {
-                mUseIndex = useIndex; 
-            }
-            
-            void setActiveIndex(size_t activeIndex) {
-                mActiveIndex = activeIndex;
-            }
-
-            void initializeUses(storm::storage::DFTState<ValueType>& state) {
-                assert(this->mChildren.size() > 0);
-                state.setUsesAtPosition(mUseIndex, this->mChildren[0]->id());
-            }
-
             void checkFails(storm::storage::DFTState<ValueType>& state, DFTStateSpaceGenerationQueues<ValueType>& queues) const override {
                 if(state.isOperational(this->mId)) {
-                    size_t uses = state.extractUses(mUseIndex);
+                    size_t uses = state.uses(this->mId);
                     if(!state.isOperational(uses)) {
-                        bool claimingSuccessful = state.claimNew(this->mId, mUseIndex, uses, this->mChildren);
+                        bool claimingSuccessful = state.claimNew(this->mId, uses, this->mChildren);
                         if(!claimingSuccessful) {
                             this->fail(state, queues);
                         }
@@ -946,7 +929,7 @@ namespace storm {
 
             void checkFailsafe(storm::storage::DFTState<ValueType>& state, DFTStateSpaceGenerationQueues<ValueType>& queues) const override {
                 if(state.isOperational(this->mId)) {
-                    if(state.isFailsafe(state.extractUses((mUseIndex)))) {
+                    if(state.isFailsafe(state.uses(this->mId))) {
                         this->failsafe(state, queues);
                         this->childrenDontCare(state, queues);
                     }

src/storage/dft/DFTState.cpp

@@ -6,10 +6,25 @@ namespace storm {
     namespace storage {
 
         template<typename ValueType>
-        DFTState<ValueType>::DFTState(DFT<ValueType> const& dft, size_t id) : mStatus(dft.stateVectorSize()), mId(id), mDft(dft)  {
+        DFTState<ValueType>::DFTState(DFT<ValueType> const& dft, DFTStateGenerationInfo const& stateGenerationInfo, size_t id) : mStatus(dft.stateVectorSize()), mId(id), mDft(dft), mStateGenerationInfo(stateGenerationInfo)  {
             mInactiveSpares = dft.getSpareIndices();
-            dft.initializeUses(*this);
-            dft.initializeActivation(*this);
+            
+            // Initialize uses
+            for(size_t id  : mDft.getSpareIndices()) {
+                std::shared_ptr<DFTGate<ValueType> const> elem = mDft.getGate(id);
+                assert(elem->isSpareGate());
+                assert(elem->nrChildren() > 0);
+                this->setUses(id, elem->children()[0]->id());
+            }
+            
+            // Initialize activation
+            this->activate(mDft.getTopLevelIndex());
+            for(auto const& id : mDft.module(mDft.getTopLevelIndex())) {
+                if(mDft.getElement(id)->isSpareGate()) {
+                    propagateActivation(uses(id));
+                }
+            }
+
             std::vector<size_t> alwaysActiveBEs = dft.nonColdBEs();
             mIsCurrentlyFailableBE.insert(mIsCurrentlyFailableBE.end(), alwaysActiveBEs.begin(), alwaysActiveBEs.end());
         }
@@ -26,7 +41,7 @@ namespace storm {
 
         template<typename ValueType>
         int DFTState<ValueType>::getElementStateInt(size_t id) const {
-            return mStatus.getAsInt(mDft.failureIndex(id), 2);
+            return mStatus.getAsInt(mStateGenerationInfo.getStateIndex(id), 2);
         }
 
         template<typename ValueType>
@@ -46,12 +61,12 @@ namespace storm {
 
         template<typename ValueType>
         bool DFTState<ValueType>::hasFailed(size_t id) const {
-            return mStatus[mDft.failureIndex(id)];
+            return mStatus[mStateGenerationInfo.getStateIndex(id)];
         }
 
         template<typename ValueType>
         bool DFTState<ValueType>::isFailsafe(size_t id) const {
-            return mStatus[mDft.failureIndex(id)+1];
+            return mStatus[mStateGenerationInfo.getStateIndex(id)+1];
         }
 
         template<typename ValueType>
@@ -66,38 +81,38 @@ namespace storm {
         
         template<typename ValueType>
         bool DFTState<ValueType>::dependencySuccessful(size_t id) const {
-            return mStatus[mDft.failureIndex(id)];
+            return mStatus[mStateGenerationInfo.getStateIndex(id)];
         }
         template<typename ValueType>
         bool DFTState<ValueType>::dependencyUnsuccessful(size_t id) const {
-            return mStatus[mDft.failureIndex(id)+1];
+            return mStatus[mStateGenerationInfo.getStateIndex(id)+1];
         }
 
         template<typename ValueType>
         void DFTState<ValueType>::setFailed(size_t id) {
-            mStatus.set(mDft.failureIndex(id));
+            mStatus.set(mStateGenerationInfo.getStateIndex(id));
         }
 
         template<typename ValueType>
         void DFTState<ValueType>::setFailsafe(size_t id) {
-            mStatus.set(mDft.failureIndex(id)+1);
+            mStatus.set(mStateGenerationInfo.getStateIndex(id)+1);
         }
 
         template<typename ValueType>
         void DFTState<ValueType>::setDontCare(size_t id) {
-            mStatus.setFromInt(mDft.failureIndex(id), 2, static_cast<uint_fast64_t>(DFTElementState::DontCare) );
+            mStatus.setFromInt(mStateGenerationInfo.getStateIndex(id), 2, static_cast<uint_fast64_t>(DFTElementState::DontCare) );
         }
         
         template<typename ValueType>
         void DFTState<ValueType>::setDependencySuccessful(size_t id) {
             // No distinction between successful dependency and no dependency at all
-            // -> we do not set bit
-            //mStatus.set(mDft.failureIndex(id));
+            // => we do not set bit
+            //mStatus.set(mStateGenerationInfo.mIdToStateIndex(id));
         }
 
         template<typename ValueType>
         void DFTState<ValueType>::setDependencyUnsuccessful(size_t id) {
-            mStatus.set(mDft.failureIndex(id)+1);
+            mStatus.set(mStateGenerationInfo.getStateIndex(id)+1);
         }
 
         template<typename ValueType>
@@ -157,8 +172,7 @@ namespace storm {
 
         template<typename ValueType>
         void DFTState<ValueType>::activate(size_t repr) {
-            std::vector<size_t>  const& module = mDft.module(repr);
-            for(size_t elem : module) {
+            for(size_t elem : mDft.module(repr)) {
                 if(mDft.getElement(elem)->isColdBasicElement() && isOperational(elem)) {
                     mIsCurrentlyFailableBE.push_back(elem);
                 }
@@ -174,16 +188,26 @@ namespace storm {
             assert(mDft.getElement(id)->isSpareGate());
             return (std::find(mInactiveSpares.begin(), mInactiveSpares.end(), id) == mInactiveSpares.end());
         }
+            
+        template<typename ValueType>
+        void DFTState<ValueType>::propagateActivation(size_t representativeId) {
+            activate(representativeId);
+            for(size_t id : mDft.module(representativeId)) {
+                if(mDft.getElement(id)->isSpareGate()) {
+                    propagateActivation(uses(id));
+                }
+            }
+        }
 
         template<typename ValueType>
         uint_fast64_t DFTState<ValueType>::uses(size_t id) const {
-            return extractUses(mDft.usageIndex(id));
+            return extractUses(mStateGenerationInfo.getSpareUsageIndex(id));
         }
 
         template<typename ValueType>
         uint_fast64_t DFTState<ValueType>::extractUses(size_t from) const {
-            assert(mDft.usageInfoBits() < 64);
-            return mStatus.getAsInt(from, mDft.usageInfoBits());
+            assert(mStateGenerationInfo.usageInfoBits() < 64);
+            return mStatus.getAsInt(from, mStateGenerationInfo.usageInfoBits());
         }
 
         template<typename ValueType>
@@ -192,13 +216,13 @@ namespace storm {
         }
 
         template<typename ValueType>
-        void DFTState<ValueType>::setUsesAtPosition(size_t usageIndex, size_t child) {
-            mStatus.setFromInt(usageIndex, mDft.usageInfoBits(), child);
+        void DFTState<ValueType>::setUses(size_t spareId, size_t child) {
+            mStatus.setFromInt(mStateGenerationInfo.getSpareUsageIndex(spareId), mStateGenerationInfo.usageInfoBits(), child);
             mUsedRepresentants.push_back(child);
         }
 
         template<typename ValueType>
-        bool DFTState<ValueType>::claimNew(size_t spareId, size_t usageIndex, size_t currentlyUses, std::vector<std::shared_ptr<DFTElement<ValueType>>> const& children) {
+        bool DFTState<ValueType>::claimNew(size_t spareId, size_t currentlyUses, std::vector<std::shared_ptr<DFTElement<ValueType>>> const& children) {
             auto it = children.begin();
             while ((*it)->id() != currentlyUses) {
                 assert(it != children.end());
@@ -208,9 +232,9 @@ namespace storm {
             while(it != children.end()) {
                 size_t childId = (*it)->id();
                 if(!hasFailed(childId) && !isUsed(childId)) {
-                    setUsesAtPosition(usageIndex, childId);
+                    setUses(spareId, childId);
                     if(isActiveSpare(spareId)) {
-                        mDft.propagateActivation(*this, childId);
+                        propagateActivation(childId);
                     }
                     return true;
                 }

src/storage/dft/DFTState.h

@@ -17,6 +17,7 @@ namespace storm {
         class DFTBE;
         template<typename ValueType>
         class DFTElement;
+        class DFTStateGenerationInfo;
 
         template<typename ValueType>
         class DFTState {
@@ -31,9 +32,10 @@ namespace storm {
             std::vector<size_t> mUsedRepresentants;
             bool mValid = true;
             const DFT<ValueType>& mDft;
+            const DFTStateGenerationInfo& mStateGenerationInfo;
             
         public:
-            DFTState(DFT<ValueType> const& dft, size_t id);
+            DFTState(DFT<ValueType> const& dft, DFTStateGenerationInfo const& stateGenerationInfo, size_t id);
             
             DFTElementState getElementState(size_t id) const;
             
@@ -75,6 +77,8 @@ namespace storm {
             
             bool isActiveSpare(size_t id) const;
             
+            void propagateActivation(size_t representativeId);
+            
             void markAsInvalid() {
                 mValid = false;
             }
@@ -109,13 +113,13 @@ namespace storm {
             bool isUsed(size_t child) const;
             
             /**
-             * Sets to to the usageIndex which child is now used.
-             * @param usageIndex 
-             * @param child
+             * Sets for the spare which child is now used.
+             * @param spareId Id of the spare
+             * @param child Id of the child which is now used
              */
-            void setUsesAtPosition(size_t usageIndex, size_t child);
+            void setUses(size_t spareId, size_t child);
             
-            bool claimNew(size_t spareId, size_t usageIndex, size_t currentlyUses, std::vector<std::shared_ptr<DFTElement<ValueType>>> const& children);
+            bool claimNew(size_t spareId, size_t currentlyUses, std::vector<std::shared_ptr<DFTElement<ValueType>>> const& children);
             
             bool hasOutgoingEdges() const {
                 return !mIsCurrentlyFailableBE.empty();