dehnert
11 years ago
9 changed files with 284 additions and 29 deletions
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4src/settings/modules/GeneralSettings.cpp
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183src/storage/BisimulationDecomposition.cpp
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11src/storage/BisimulationDecomposition.h
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5src/storage/Decomposition.cpp
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56src/storage/Distribution.cpp
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32src/storage/Distribution.h
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5src/storage/StateBlock.cpp
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7src/storage/StateBlock.h
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10src/utility/cli.h
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#include "src/storage/BisimulationDecomposition.h"
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#include <queue>
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#include <unordered_map>
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#include <chrono>
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namespace storm { |
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namespace storage { |
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template<typename ValueType> |
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BisimulationDecomposition<ValueType>::BisimulationDecomposition(storm::models::Dtmc<ValueType> const& model, bool weak) { |
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computeBisimulationEquivalenceClasses(model, weak); |
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BisimulationDecomposition<ValueType>::BisimulationDecomposition(storm::models::Dtmc<ValueType> const& dtmc, bool weak) { |
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computeBisimulationEquivalenceClasses(dtmc, weak); |
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} |
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template<typename ValueType> |
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void BisimulationDecomposition<ValueType>::computeBisimulationEquivalenceClasses(storm::models::Dtmc<ValueType> const& model, bool weak) { |
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void BisimulationDecomposition<ValueType>::computeBisimulationEquivalenceClasses(storm::models::Dtmc<ValueType> const& dtmc, bool weak) { |
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std::chrono::high_resolution_clock::time_point totalStart = std::chrono::high_resolution_clock::now(); |
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// We start by computing the initial partition. In particular, we also keep a mapping of states to their blocks.
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std::vector<std::size_t> stateToBlockMapping(model.getNumberOfStates()); |
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storm::storage::BitVector labeledStates = model.getLabeledStates("one"); |
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std::vector<std::size_t> stateToBlockMapping(dtmc.getNumberOfStates()); |
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storm::storage::BitVector labeledStates = dtmc.getLabeledStates("observe0Greater1"); |
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this->blocks.emplace_back(labeledStates.begin(), labeledStates.end()); |
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std::for_each(labeledStates.begin(), labeledStates.end(), [&] (storm::storage::sparse::state_type const& state) { stateToBlockMapping[state] = 0; } ); |
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labeledStates.complement(); |
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this->blocks.emplace_back(labeledStates.begin(), labeledStates.end()); |
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std::for_each(labeledStates.begin(), labeledStates.end(), [&] (storm::storage::sparse::state_type const& state) { stateToBlockMapping[state] = 1; } ); |
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// Create empty distributions for the two initial blocks.
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std::vector<storm::storage::Distribution<ValueType>> distributions(2); |
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// Retrieve the backward transitions to allow for better checking of states that need to be re-examined.
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storm::storage::SparseMatrix<ValueType> const& backwardTransitions = model.getBackwardTransitions(); |
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storm::storage::SparseMatrix<ValueType> const& backwardTransitions = dtmc.getBackwardTransitions(); |
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// Initially, both blocks are potential splitters.
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std::queue<std::size_t> splitterQueue; |
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splitterQueue.push(0); |
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splitterQueue.push(1); |
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// As long as there is a splitter, we keep refining the current partition.
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while (!splitterQueue.empty()) { |
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// Initially, both blocks are potential splitters. A splitter is marked as a pair in which the first entry
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// is the ID of the parent block of the splitter and the second entry is the block ID of the splitter itself.
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std::deque<std::size_t> refinementQueue; |
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storm::storage::BitVector blocksInRefinementQueue(this->size()); |
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refinementQueue.push_back(0); |
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refinementQueue.push_back(1); |
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// As long as there are blocks to refine, well, refine them.
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uint_fast64_t iteration = 0; |
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while (!refinementQueue.empty()) { |
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++iteration; |
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// Optionally sort the queue to potentially speed up the convergence.
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// std::sort(refinementQueue.begin(), refinementQueue.end(), [=] (std::size_t const& a, std::size_t const& b) { return this->blocks[a].size() > this->blocks[b].size(); });
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std::size_t currentBlock = refinementQueue.front(); |
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refinementQueue.pop_front(); |
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blocksInRefinementQueue.set(currentBlock, false); |
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splitBlock(dtmc, backwardTransitions, currentBlock, stateToBlockMapping, distributions, blocksInRefinementQueue, refinementQueue); |
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} |
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// While there is a splitter...
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//
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// check the predecessors of the splitter:
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// * if they still have the same signature as before, then they remain unsplit
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// * otherwise, split off the states that now behave differently
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// and mark the smaller block as a splitter
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std::chrono::high_resolution_clock::duration totalTime = std::chrono::high_resolution_clock::now() - totalStart; |
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//
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std::cout << "Bisimulation quotient has " << this->blocks.size() << " blocks and took " << iteration << " iterations and " << std::chrono::duration_cast<std::chrono::milliseconds>(totalTime).count() << "ms." << std::endl; |
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} |
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template<typename ValueType> |
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std::size_t BisimulationDecomposition<ValueType>::splitPredecessorsGraphBased(storm::models::Dtmc<ValueType> const& dtmc, storm::storage::SparseMatrix<ValueType> const& backwardTransitions, std::size_t const& blockId, std::vector<std::size_t>& stateToBlockMapping, std::vector<storm::storage::Distribution<ValueType>>& distributions, storm::storage::BitVector& blocksInRefinementQueue, std::deque<std::size_t>& graphRefinementQueue) { |
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// This method tries to split the blocks of predecessors of the provided block by checking whether there is
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// a transition into the current block or not.
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std::unordered_map<std::size_t, typename BisimulationDecomposition<ValueType>::block_type> predecessorBlockToNewBlock; |
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// Now for each predecessor block which state could actually reach the current block.
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for (auto const& state : this->blocks[blockId]) { |
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for (auto const& predecessorEntry : backwardTransitions.getRow(state)) { |
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storm::storage::sparse::state_type predecessor = predecessorEntry.getColumn(); |
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predecessorBlockToNewBlock[stateToBlockMapping[predecessor]].insert(predecessor); |
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} |
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} |
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// Now, we can check for each predecessor block whether it needs to be split.
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for (auto const& blockNewBlockPair : predecessorBlockToNewBlock) { |
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if (this->blocks[blockNewBlockPair.first].size() > blockNewBlockPair.second.size()) { |
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// Add the states which have a successor in the current block to a totally new block.
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this->blocks.emplace_back(std::move(blockNewBlockPair.second)); |
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// Compute the set of states that remains in the old block;
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typename BisimulationDecomposition<ValueType>::block_type newBlock; |
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std::set_difference(this->blocks[blockId].begin(), this->blocks[blockId].end(), this->blocks.back().begin(), this->blocks.back().end(), std::inserter(newBlock, newBlock.begin())); |
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this->blocks[blockNewBlockPair.first] = std::move(newBlock); |
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blocksInRefinementQueue.resize(this->blocks.size()); |
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// Add the smaller part of the old block to the queue.
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std::size_t blockToAddToQueue = this->blocks.back().size() < this->blocks[blockNewBlockPair.first].size() ? this->blocks.size() - 1 : blockNewBlockPair.first; |
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if (!blocksInRefinementQueue.get(blockToAddToQueue)) { |
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graphRefinementQueue.push_back(blockToAddToQueue); |
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blocksInRefinementQueue.set(blockToAddToQueue, true); |
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} |
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} |
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} |
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// FIXME
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return 0; |
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} |
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template<typename ValueType> |
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std::size_t BisimulationDecomposition<ValueType>::splitBlock(storm::models::Dtmc<ValueType> const& dtmc, storm::storage::SparseMatrix<ValueType> const& backwardTransitions, std::size_t const& blockId, std::vector<std::size_t>& stateToBlockMapping, std::vector<storm::storage::Distribution<ValueType>>& distributions, storm::storage::BitVector& blocksInRefinementQueue, std::deque<std::size_t>& refinementQueue) { |
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std::chrono::high_resolution_clock::time_point totalStart = std::chrono::high_resolution_clock::now(); |
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std::unordered_map<storm::storage::Distribution<ValueType>, typename BisimulationDecomposition<ValueType>::block_type> distributionToNewBlocks; |
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// Traverse all states of the block and check whether they have different distributions.
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for (auto const& state : this->blocks[blockId]) { |
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// Now construct the distribution of this state wrt. to the current partitioning.
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storm::storage::Distribution<ValueType> distribution; |
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for (auto const& successorEntry : dtmc.getTransitionMatrix().getRow(state)) { |
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distribution.addProbability(static_cast<storm::storage::sparse::state_type>(stateToBlockMapping[successorEntry.getColumn()]), successorEntry.getValue()); |
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} |
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// If the distribution already exists, we simply add the state. Otherwise, we open a new block.
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auto distributionIterator = distributionToNewBlocks.find(distribution); |
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if (distributionIterator != distributionToNewBlocks.end()) { |
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distributionIterator->second.insert(state); |
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} else { |
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distributionToNewBlocks[distribution].insert(state); |
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} |
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} |
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// Now we are ready to split the block.
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if (distributionToNewBlocks.size() == 1) { |
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// If there is just one behavior, we just set the distribution as the new one for this block.
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distributions[blockId] = std::move(distributionToNewBlocks.begin()->first); |
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} else { |
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// In this case, we need to split the block.
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typename BisimulationDecomposition<ValueType>::block_type tmpBlock; |
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auto distributionIterator = distributionToNewBlocks.begin(); |
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distributions[blockId] = std::move(distributionIterator->first); |
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tmpBlock = std::move(distributionIterator->second); |
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std::swap(this->blocks[blockId], tmpBlock); |
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++distributionIterator; |
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// Remember the number of blocks prior to splitting for later use.
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std::size_t beforeNumberOfBlocks = this->blocks.size(); |
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for (; distributionIterator != distributionToNewBlocks.end(); ++distributionIterator) { |
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// In this case, we need to move the newly created block to the end of the list of actual blocks.
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this->blocks.emplace_back(std::move(distributionIterator->second)); |
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distributions.emplace_back(std::move(distributionIterator->first)); |
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// Update the mapping of states to their blocks.
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std::size_t newBlockId = this->blocks.size() - 1; |
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for (auto const& state : this->blocks.back()) { |
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stateToBlockMapping[state] = newBlockId; |
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} |
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} |
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// Now that we have split the block, we try to trigger a chain of graph-based splittings. That is, we
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// try to split the predecessors of the current block by checking whether they have some transition
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// to one given sub-block of the current block.
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std::deque<std::size_t> localRefinementQueue; |
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storm::storage::BitVector blocksInLocalRefinementQueue(this->size()); |
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localRefinementQueue.push_back(blockId); |
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for (std::size_t i = beforeNumberOfBlocks; i < this->blocks.size(); ++i) { |
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localRefinementQueue.push_back(i); |
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} |
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while (!localRefinementQueue.empty()) { |
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std::size_t currentBlock = localRefinementQueue.front(); |
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localRefinementQueue.pop_front(); |
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blocksInLocalRefinementQueue.set(currentBlock, false); |
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splitPredecessorsGraphBased(dtmc, backwardTransitions, blockId, stateToBlockMapping, distributions, blocksInLocalRefinementQueue, localRefinementQueue); |
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} |
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// Since we created some new blocks, we need to extend the bit vector storing the blocks in the
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// refinement queue.
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blocksInRefinementQueue.resize(blocksInRefinementQueue.size() + (distributionToNewBlocks.size() - 1)); |
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// Insert blocks that possibly need a refinement into the queue.
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for (auto const& state : tmpBlock) { |
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for (auto const& predecessor : backwardTransitions.getRow(state)) { |
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if (!blocksInRefinementQueue.get(stateToBlockMapping[predecessor.getColumn()])) { |
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blocksInRefinementQueue.set(stateToBlockMapping[predecessor.getColumn()]); |
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refinementQueue.push_back(stateToBlockMapping[predecessor.getColumn()]); |
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} |
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} |
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} |
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} |
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std::chrono::high_resolution_clock::duration totalTime = std::chrono::high_resolution_clock::now() - totalStart; |
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std::cout << "refinement of block " << blockId << " took " << std::chrono::duration_cast<std::chrono::milliseconds>(totalTime).count() << "ms." << std::endl; |
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return distributionToNewBlocks.size(); |
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} |
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template class BisimulationDecomposition<double>; |
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