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

Better comments for SMT generation

tempestpy_adaptions
Matthias Volk 7 years ago
parent
8051912147
commit
34911003e0
1 changed files with 51 additions and 14 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. 63
      src/storm-dft/modelchecker/dft/DFTASFChecker.cpp

63
src/storm-dft/modelchecker/dft/DFTASFChecker.cpp
View File

@ -271,7 +271,8 @@ namespace storm {
void DFTASFChecker::convert() {
std::vector<uint64_t> beVariables;
// Convert all elements
// Initialize variables
for (size_t i = 0; i < dft.nrElements(); ++i) {
std::shared_ptr<storm::storage::DFTElement<ValueType> const> element = dft.getElement(i);
varNames.push_back("t_" + element->name());
@ -294,21 +295,28 @@ namespace storm {
}
}
// BE
// Generate constraints
// No two BEs fail at the same time (first part of constraint 12)
constraints.push_back(std::make_shared<PairwiseDifferent>(beVariables));
constraints.back()->setDescription("No two BEs fail at the same time");
// All BEs have to fail (second part of constraint 12)
for (auto const& beV : beVariables) {
constraints.push_back(std::make_shared<BetweenValues>(beV, 1, dft.nrBasicElements()));
}
// Claim variables
for (auto const& csvV : claimVariables) {
constraints.push_back(std::make_shared<BetweenValues>(csvV.second, 0, dft.nrBasicElements() + 1));
// Initialize claim variables in [1, |BE|+1]
for (auto const& claimVariable : claimVariables) {
constraints.push_back(std::make_shared<BetweenValues>(claimVariable.second, 0, dft.nrBasicElements() + 1));
}
// First child of each spare is claimed in the beginning
for (size_t i = 0; i < dft.nrElements(); ++i) {
std::shared_ptr<storm::storage::DFTElement<ValueType> const> element = dft.getElement(i);
if(element->isSpareGate()) {
if (element->isSpareGate()) {
auto spare = std::static_pointer_cast<storm::storage::DFTSpare<double> const>(element);
auto const& spareChild = spare->children().front();
constraints.push_back(std::make_shared<IsConstantValue>(getClaimVariableIndex(spare->id(), spareChild->id()), 0));
@ -317,7 +325,9 @@ namespace storm {
}
}
// Encoding for specific gates
for (size_t i = 0; i < dft.nrElements(); ++i) {
// Get indices for gate children
std::vector<uint64_t> childVarIndices;
if (dft.isGate(i)) {
std::shared_ptr<storm::storage::DFTGate<ValueType> const> gate = dft.getGate(i);
@ -328,25 +338,39 @@ namespace storm {
std::shared_ptr<storm::storage::DFTElement<ValueType> const> element = dft.getElement(i);
switch (element->type()) {
case storm::storage::DFTElementType::BE:
// BEs were already considered before
break;
case storm::storage::DFTElementType::AND:
// Constraint for AND gate (constraint 1)
constraints.push_back(std::make_shared<IsMaximum>(timePointVariables.at(i), childVarIndices));
constraints.back()->setDescription("And gate");
break;
case storm::storage::DFTElementType::OR:
// Constraint for OR gate (constraint 2)
constraints.push_back(std::make_shared<IsMinimum>(timePointVariables.at(i), childVarIndices));
constraints.back()->setDescription("Or gate");
break;
case storm::storage::DFTElementType::PAND:
constraints.push_back(std::make_shared<IfThenElse>(std::make_shared<Sorted>(childVarIndices), std::make_shared<IsEqual>(timePointVariables.at(i), timePointVariables.at(childVarIndices.back())), std::make_shared<IsConstantValue>(timePointVariables.at(i), dft.nrBasicElements()+1)));
{
// Constraint for PAND gate (constraint 3)
std::shared_ptr<DFTConstraint> ifC = std::make_shared<Sorted>(childVarIndices);
std::shared_ptr<DFTConstraint> thenC = std::make_shared<IsEqual>(timePointVariables.at(i), timePointVariables.at(childVarIndices.back()));
std::shared_ptr<DFTConstraint> elseC = std::make_shared<IsConstantValue>(timePointVariables.at(i), dft.nrBasicElements()+1);
constraints.push_back(std::make_shared<IfThenElse>(ifC, thenC, elseC));
constraints.back()->setDescription("Pand gate");
}
case storm::storage::DFTElementType::SPARE:
{
auto spare = std::static_pointer_cast<storm::storage::DFTSpare<double> const>(element);
auto const& children = spare->children();
constraints.push_back(std::make_shared<Iff>(std::make_shared<IsLEqual>(getClaimVariableIndex(spare->id(), children.back()->id()), childVarIndices.back()), std::make_shared<IsEqual>(timePointVariables.at(i), childVarIndices.back())));
// If last child is claimed before failure the spare fails when the last child fails (constraint 5)
std::shared_ptr<DFTConstraint> leftC = std::make_shared<IsLEqual>(getClaimVariableIndex(spare->id(), children.back()->id()), childVarIndices.back());
constraints.push_back(std::make_shared<Iff>(leftC, std::make_shared<IsEqual>(timePointVariables.at(i), childVarIndices.back())));
constraints.back()->setDescription("Last child & claimed -> spare fails");
// Construct constraint for claiming
std::shared_ptr<DFTConstraint> elseCase = nullptr;
for (uint64_t j = 0; j < children.size(); ++j) {
uint64_t currChild = children.size() - 2 - j;
@ -354,22 +378,35 @@ namespace storm {
uint64_t xv = childVarIndices.at(currChild); // if v is the child, xv is the time x fails.
uint64_t csn = getClaimVariableIndex(spare->id(), childVarIndices.at(currChild+1)); // csn is the moment the spare claims the next child
uint64_t xn = childVarIndices.at(currChild+1); // xn is the moment the next child fails
// Generate constraint for trying to claim next child
if (j == 0) {
// Last child: spare fails at same point as xv (otherwise case in constraint 7)
elseCase = std::make_shared<IsEqual>(timePointVariables.at(i), xv);
}
// Next child is not yet failed
ifcs.push_back(std::make_shared<IsLEqual>(xv, xn));
// Child is not yet claimed by a different spare (first part of case distinction for constraint 7)
for (auto const& otherSpare : children.at(currChild+1)->parents()) {
if (otherSpare->id() == i) { continue; }// not a OTHER spare.
if (otherSpare->id() == i) {
// not an OTHER spare.
continue;
}
ifcs.push_back(std::make_shared<IsConstantValue>(getClaimVariableIndex(otherSpare->id(), children.at(currChild+1)->id()), dft.nrBasicElements()+1));
}
std::shared_ptr<DFTConstraint> ite = std::make_shared<IfThenElse>(std::make_shared<And>(ifcs), std::make_shared<IsEqual>(csn, xv), elseCase);
elseCase = ite;
constraints.push_back(std::make_shared<Iff>(std::make_shared<IsLEqual>(getClaimVariableIndex(spare->id(), children.at(currChild)->id()), xv), ite));
// Claim next child (constraint 7)
// elseCase contains the constraints for the recursive call to phi^s_{i+1}
std::shared_ptr<DFTConstraint> tryClaimC = std::make_shared<IfThenElse>(std::make_shared<And>(ifcs), std::make_shared<IsEqual>(csn, xv), elseCase);
elseCase = tryClaimC;
// If i-th child fails after being claimed, then try to claim (i+1)-th child (constraint 6)
constraints.push_back(std::make_shared<Iff>(std::make_shared<IsLEqual>(getClaimVariableIndex(spare->id(), children.at(currChild)->id()), xv), tryClaimC));
constraints.back()->setDescription(std::to_string(j+1) + " but last child & claimed");
}
break;
}
default:
STORM_LOG_WARN("DFT element of type '" << element->type() << "' is ignored for SMT encoding.");
break;
}
}

Write Preview
Loading…
Cancel
Save