sp
/
tempest
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity
Browse Source

advanced stopping criteria for multi-counterexamples, additional measurements for cuts, an option to properly disable backward implications, and some cleaning

main
Sebastian Junges 7 years ago
parent
ac9d9d6778
commit
73900f1bbe
1 changed files with 128 additions and 87 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 215
      src/storm-counterexamples/counterexamples/SMTMinimalLabelSetGenerator.h

215
src/storm-counterexamples/counterexamples/SMTMinimalLabelSetGenerator.h
View File

@ -28,7 +28,20 @@ namespace storm {
class Environment;
namespace counterexamples {
/**
* Helper to avoid case disticinot between prism and jani
* Returns the number of edges/commands in a symbolic model description.
*/
size_t nrCommands(storm::storage::SymbolicModelDescription const& descr) {
if (descr.isJaniModel()) {
return descr.asJaniModel().getNumberOfEdges();
} else {
assert(descr.isPrismModel());
return descr.asPrismProgram().getNumberOfCommands();
}
}
/*!
* This class provides functionality to generate a minimal counterexample to a probabilistic reachability
* property in terms of used labels.
@ -313,12 +326,18 @@ namespace storm {
* @param context The Z3 context in which to build the expressions.
* @param solver The solver to use for the satisfiability evaluation.
*/
static void assertCuts(storm::storage::SymbolicModelDescription const& symbolicModel, storm::models::sparse::Model<T> const& model, std::vector<boost::container::flat_set<uint_fast64_t>> const& labelSets, storm::storage::BitVector const& psiStates, VariableInformation const& variableInformation, RelevancyInformation const& relevancyInformation, storm::solver::SmtSolver& solver) {
static std::chrono::milliseconds assertCuts(storm::storage::SymbolicModelDescription const& symbolicModel, storm::models::sparse::Model<T> const& model, std::vector<boost::container::flat_set<uint_fast64_t>> const& labelSets, storm::storage::BitVector const& psiStates, VariableInformation const& variableInformation, RelevancyInformation const& relevancyInformation, storm::solver::SmtSolver& solver, bool addBackwardImplications) {
// Walk through the model and
// * identify labels enabled in initial states
// * identify labels that can directly precede a given action
// * identify labels that directly reach a target state
// * identify labels that can directly follow a given action
auto assertCutsClock = std::chrono::high_resolution_clock::now();
//
if (addBackwardImplications) {
STORM_LOG_THROW(!symbolicModel.isJaniModel() || !symbolicModel.asJaniModel().usesAssignmentLevels(), storm::exceptions::NotSupportedException, "Counterexample generation with backward implications is not supported for indexed assignments");
}
boost::container::flat_set<uint_fast64_t> initialLabels;
std::set<boost::container::flat_set<uint_fast64_t>> initialCombinations;
@ -334,6 +353,7 @@ namespace storm {
storm::storage::BitVector const& initialStates = model.getInitialStates();
for (auto currentState : relevancyInformation.relevantStates) {
bool isInitial = initialStates.get(currentState);
for (auto currentChoice : relevancyInformation.relevantChoicesForRelevantStates.at(currentState)) {
// If the choice is a synchronization choice, we need to record it.
@ -344,7 +364,7 @@ namespace storm {
}
// If the state is initial, we need to add all the choice labels to the initial label set.
if (initialStates.get(currentState)) {
if (isInitial) {
initialLabels.insert(labelSets[currentChoice].begin(), labelSets[currentChoice].end());
initialCombinations.insert(labelSets[currentChoice]);
}
@ -378,6 +398,7 @@ namespace storm {
for (auto const& successorEntry : transitionMatrix.getRow(predecessorChoice)) {
if (successorEntry.getColumn() == currentState) {
choiceTargetsCurrentState = true;
break;
}
}
@ -389,11 +410,10 @@ namespace storm {
}
}
}
// Store the found implications in a container similar to the preceding label sets.
std::map<boost::container::flat_set<uint_fast64_t>, std::set<boost::container::flat_set<uint_fast64_t>>> backwardImplications;
if (!symbolicModel.isJaniModel() || !symbolicModel.asJaniModel().usesAssignmentLevels()) {
if (addBackwardImplications) {
// Create a new solver over the same variables as the given symbolic model description to use it for
// determining the symbolic cuts.
std::unique_ptr<storm::solver::SmtSolver> localSolver;
@ -587,8 +607,7 @@ namespace storm {
// Iterate over all possible combinations of updates of the preceding command set.
std::vector<storm::expressions::Expression> formulae;
bool done = false;
while (!done) {
while (true) {
std::map<storm::expressions::Variable, storm::expressions::Expression> currentVariableUpdateCombinationMap;
for (auto const& updateIterator : iteratorVector) {
for (auto const& variableUpdatePair : *updateIterator) {
@ -616,7 +635,7 @@ namespace storm {
// If we had to reset all iterator to the start, we are done.
if (k == 0) {
done = true;
break;
}
}
@ -722,85 +741,88 @@ namespace storm {
assertDisjunction(solver, formulae, *variableInformation.manager);
}
}
STORM_LOG_DEBUG("Asserting taken labels are followed and preceeded by another label if they are not a target label or an initial label, respectively.");
boost::container::flat_map<boost::container::flat_set<uint_fast64_t>, storm::expressions::Expression> labelSetToFormula;
for (auto const& labelSet : relevancyInformation.relevantLabelSets) {
storm::expressions::Expression labelSetFormula = variableInformation.manager->boolean(false);
// Compute the set of unknown labels on the left-hand side of the implication.
boost::container::flat_set<uint_fast64_t> unknownLhsLabels;
std::set_difference(labelSet.begin(), labelSet.end(), relevancyInformation.knownLabels.begin(), relevancyInformation.knownLabels.end(), std::inserter(unknownLhsLabels, unknownLhsLabels.end()));
for (auto label : unknownLhsLabels) {
labelSetFormula = labelSetFormula || !variableInformation.labelVariables.at(variableInformation.labelToIndexMap.at(label));
}
// Only build a constraint if the combination does not lead to a target state and
// no successor set is already known.
storm::expressions::Expression successorExpression;
if (targetCombinations.find(labelSet) == targetCombinations.end() && hasKnownSuccessor.find(labelSet) == hasKnownSuccessor.end()) {
successorExpression = variableInformation.manager->boolean(false);
if(addBackwardImplications) {
auto const& followingLabelSets = followingLabels.at(labelSet);
STORM_LOG_DEBUG("Asserting taken labels are followed and preceeded by another label if they are not a target label or an initial label, respectively.");
boost::container::flat_map<boost::container::flat_set<uint_fast64_t>, storm::expressions::Expression> labelSetToFormula;
for (auto const &labelSet : relevancyInformation.relevantLabelSets) {
storm::expressions::Expression labelSetFormula = variableInformation.manager->boolean(false);
for (auto const& followingSet : followingLabelSets) {
boost::container::flat_set<uint_fast64_t> tmpSet;
// Check which labels of the current following set are not known. This set must be non-empty, because
// otherwise a successor combination would already be known and control cannot reach this point.
std::set_difference(followingSet.begin(), followingSet.end(), relevancyInformation.knownLabels.begin(), relevancyInformation.knownLabels.end(), std::inserter(tmpSet, tmpSet.end()));
// Construct an expression that enables all unknown labels of the current following set.
storm::expressions::Expression conj = variableInformation.manager->boolean(true);
for (auto label : tmpSet) {
conj = conj && variableInformation.labelVariables.at(variableInformation.labelToIndexMap.at(label));
// Compute the set of unknown labels on the left-hand side of the implication.
boost::container::flat_set<uint_fast64_t> unknownLhsLabels;
std::set_difference(labelSet.begin(), labelSet.end(), relevancyInformation.knownLabels.begin(), relevancyInformation.knownLabels.end(), std::inserter(unknownLhsLabels, unknownLhsLabels.end()));
for (auto label : unknownLhsLabels) {
labelSetFormula = labelSetFormula || !variableInformation.labelVariables.at(variableInformation.labelToIndexMap.at(label));
}
// Only build a constraint if the combination does not lead to a target state and
// no successor set is already known.
storm::expressions::Expression successorExpression;
if (targetCombinations.find(labelSet) == targetCombinations.end() && hasKnownSuccessor.find(labelSet) == hasKnownSuccessor.end()) {
successorExpression = variableInformation.manager->boolean(false);
auto const &followingLabelSets = followingLabels.at(labelSet);
for (auto const &followingSet : followingLabelSets) {
boost::container::flat_set<uint_fast64_t> tmpSet;
// Check which labels of the current following set are not known. This set must be non-empty, because
// otherwise a successor combination would already be known and control cannot reach this point.
std::set_difference(followingSet.begin(), followingSet.end(), relevancyInformation.knownLabels.begin(), relevancyInformation.knownLabels.end(), std::inserter(tmpSet, tmpSet.end()));
// Construct an expression that enables all unknown labels of the current following set.
storm::expressions::Expression conj = variableInformation.manager->boolean(true);
for (auto label : tmpSet) {
conj = conj && variableInformation.labelVariables.at(variableInformation.labelToIndexMap.at(label));
}
successorExpression = successorExpression || conj;
}
successorExpression = successorExpression || conj;
} else {
successorExpression = variableInformation.manager->boolean(true);
}
} else {
successorExpression = variableInformation.manager->boolean(true);
}
// Constructed following cuts at this point.
// Only build a constraint if the combination is no initial combination and no
// predecessor set is already known.
storm::expressions::Expression predecessorExpression;
if (initialCombinations.find(labelSet) == initialCombinations.end() && hasKnownPredecessor.find(labelSet) == hasKnownPredecessor.end()) {
predecessorExpression = variableInformation.manager->boolean(false);
// Constructed following cuts at this point.
// Only build a constraint if the combination is no initial combination and no
// predecessor set is already known.
storm::expressions::Expression predecessorExpression;
if (initialCombinations.find(labelSet) == initialCombinations.end() && hasKnownPredecessor.find(labelSet) == hasKnownPredecessor.end()) {
predecessorExpression = variableInformation.manager->boolean(false);
// std::cout << "labelSet" << std::endl;
// for (auto const& e : labelSet) {
// std::cout << e << ", ";
// }
// std::cout << std::endl;
auto const& preceedingLabelSets = backwardImplications.at(labelSet);
auto const &preceedingLabelSets = backwardImplications.at(labelSet);
for (auto const& preceedingSet : preceedingLabelSets) {
boost::container::flat_set<uint_fast64_t> tmpSet;
// Check which labels of the current following set are not known. This set must be non-empty, because
// otherwise a predecessor combination would already be known and control cannot reach this point.
std::set_difference(preceedingSet.begin(), preceedingSet.end(), relevancyInformation.knownLabels.begin(), relevancyInformation.knownLabels.end(), std::inserter(tmpSet, tmpSet.end()));
// Construct an expression that enables all unknown labels of the current following set.
storm::expressions::Expression conj = variableInformation.manager->boolean(true);
for (auto label : tmpSet) {
conj = conj && variableInformation.labelVariables.at(variableInformation.labelToIndexMap.at(label));
for (auto const &preceedingSet : preceedingLabelSets) {
boost::container::flat_set<uint_fast64_t> tmpSet;
// Check which labels of the current following set are not known. This set must be non-empty, because
// otherwise a predecessor combination would already be known and control cannot reach this point.
std::set_difference(preceedingSet.begin(), preceedingSet.end(), relevancyInformation.knownLabels.begin(), relevancyInformation.knownLabels.end(), std::inserter(tmpSet, tmpSet.end()));
// Construct an expression that enables all unknown labels of the current following set.
storm::expressions::Expression conj = variableInformation.manager->boolean(true);
for (auto label : tmpSet) {
conj = conj && variableInformation.labelVariables.at(variableInformation.labelToIndexMap.at(label));
}
predecessorExpression = predecessorExpression || conj;
}
predecessorExpression = predecessorExpression || conj;
} else {
predecessorExpression = variableInformation.manager->boolean(true);
}
} else {
predecessorExpression = variableInformation.manager->boolean(true);
labelSetFormula = labelSetFormula || (successorExpression && predecessorExpression);
labelSetToFormula[labelSet] = labelSetFormula;
}
labelSetFormula = labelSetFormula || (successorExpression && predecessorExpression);
labelSetToFormula[labelSet] = labelSetFormula;
}
for (auto const& labelSetFormula : labelSetToFormula) {
solver.add(labelSetFormula.second || getOtherSynchronizationEnabledFormula(labelSetFormula.first, synchronizingLabels, labelSetToFormula, variableInformation, relevancyInformation));
for (auto const &labelSetFormula : labelSetToFormula) {
solver.add(labelSetFormula.second || getOtherSynchronizationEnabledFormula(labelSetFormula.first, synchronizingLabels, labelSetToFormula, variableInformation, relevancyInformation));
}
}
STORM_LOG_DEBUG("Asserting synchronization cuts.");
@ -837,6 +859,9 @@ namespace storm {
assertDisjunction(solver, formulae, *variableInformation.manager);
}
}
auto endTime = std::chrono::high_resolution_clock::now();
return std::chrono::duration_cast<std::chrono::milliseconds>(endTime - assertCutsClock);
}
/*!
@ -1021,10 +1046,12 @@ namespace storm {
*/
static std::vector<std::vector<storm::expressions::Expression>> createAdderPairs(VariableInformation const& variableInformation, std::vector<std::vector<storm::expressions::Expression>> const& in) {
std::vector<std::vector<storm::expressions::Expression>> result;
result.reserve(in.size() / 2 + in.size() % 2);
for (uint_fast64_t index = 0; index < in.size() / 2; ++index) {
uint64_t maxIndex = in.size() / 2;
result.reserve(maxIndex + in.size() % 2);
for (uint_fast64_t index = 0; index < maxIndex; ++index) {
result.push_back(createAdder(variableInformation, in[2 * index], in[2 * index + 1]));
}
@ -1586,9 +1613,11 @@ namespace storm {
bool encodeReachability;
bool useDynamicConstraints;
bool silent = false;
bool addBackwardImplicationCuts = true;
uint64_t continueAfterFirstCounterexampleUntil = 0;
uint64_t maximumCounterexamples = 1;
uint64_t multipleCounterexampleSizeCap = 100000000;
uint64_t maximumExtraIterations = 100000000;
};
struct GeneratorStats {
@ -1596,8 +1625,11 @@ namespace storm {
std::chrono::milliseconds solverTime;
std::chrono::milliseconds modelCheckingTime;
std::chrono::milliseconds analysisTime;
std::chrono::milliseconds cutTime;
uint64_t iterations;
};
/*!
* Computes the minimal command set that is needed in the given model to exceed the given probability threshold for satisfying phi until psi.
*
@ -1679,19 +1711,19 @@ namespace storm {
// and subsequently relax that.
variableInformation.adderVariables = assertAdder(*solver, variableInformation);
variableInformation.auxiliaryVariables.push_back(assertLessOrEqualKRelaxed(*solver, variableInformation, 0));
// As we are done with the setup at this point, stop the clock for the setup time.
totalSetupTime = std::chrono::high_resolution_clock::now() - setupTimeClock;
// (6) Add constraints that cut off a lot of suboptimal solutions.
STORM_LOG_DEBUG("Asserting cuts.");
assertCuts(symbolicModel, model, labelSets, psiStates, variableInformation, relevancyInformation, *solver);
stats.cutTime = assertCuts(symbolicModel, model, labelSets, psiStates, variableInformation, relevancyInformation, *solver, options.addBackwardImplicationCuts);
STORM_LOG_DEBUG("Asserted cuts.");
if (options.encodeReachability) {
assertReachabilityCuts(model, labelSets, psiStates, variableInformation, relevancyInformation, *solver);
STORM_LOG_DEBUG("Asserted reachability cuts.");
}
// As we are done with the setup at this point, stop the clock for the setup time.
totalSetupTime = std::chrono::high_resolution_clock::now() - setupTimeClock;
// (7) Find the smallest set of commands that satisfies all constraints. If the probability of
// satisfying phi until psi exceeds the given threshold, the set of labels is minimal and can be returned.
// Otherwise, the current solution has to be ruled out and the next smallest solution is retrieved from
@ -1712,11 +1744,17 @@ namespace storm {
uint_fast64_t lastSize = 0;
uint_fast64_t iterations = 0;
uint_fast64_t currentBound = 0;
uint64_t firstCounterexampleFound = 0; // The value is not queried before being set.
std::vector<double> maximalPropertyValue;
uint_fast64_t zeroProbabilityCount = 0;
uint64_t smallestCounterexampleSize = model.getNumberOfChoices(); // Definitive u
size_t smallestCounterexampleSize = model.getNumberOfChoices(); // Definitive upper bound
uint64_t progressDelay = storm::settings::getModule<storm::settings::modules::GeneralSettings>().getShowProgressDelay();
do {
++iterations;
if (result.size() > 0 && iterations > firstCounterexampleFound + options.maximumExtraIterations) {
break;
}
STORM_LOG_DEBUG("Computing minimal command set.");
solverClock = std::chrono::high_resolution_clock::now();
boost::optional<boost::container::flat_set<uint_fast64_t>> smallest = findSmallestCommandSet(*solver, variableInformation, currentBound);
@ -1781,19 +1819,21 @@ namespace storm {
}
} else {
STORM_LOG_DEBUG("Found a counterexample.");
if (result.empty()) {
// If this is the first counterexample we find, we store when we found it.
firstCounterexampleFound = iterations;
}
result.push_back(commandSet);
if (options.maximumCounterexamples > result.size()) {
STORM_LOG_DEBUG("Exclude counterexample for future.");
ruleOutBiggerSolutions(*solver, commandSet, variableInformation, relevancyInformation);
} else {
STORM_LOG_DEBUG("Stop searching for further counterexamples.");
done = true;
}
smallestCounterexampleSize = std::min(smallestCounterexampleSize, commandSet.size());
}
totalAnalysisTime += (std::chrono::high_resolution_clock::now() - analysisClock);
++iterations;
auto now = std::chrono::high_resolution_clock::now();
auto durationSinceLastMessage = std::chrono::duration_cast<std::chrono::seconds>(now - timeOfLastMessage).count();
@ -1816,6 +1856,7 @@ namespace storm {
stats.setupTime = std::chrono::duration_cast<std::chrono::milliseconds>(totalSetupTime);
stats.modelCheckingTime = std::chrono::duration_cast<std::chrono::milliseconds>(totalModelCheckingTime);
stats.solverTime = std::chrono::duration_cast<std::chrono::milliseconds>(totalSolverTime);
stats.iterations = iterations;
if (storm::settings::getModule<storm::settings::modules::CoreSettings>().isShowStatisticsSet()) {
boost::container::flat_set<uint64_t> allLabels;

Write Preview
Loading…
Cancel
Save