inline bool KarpMillerL1SearchStrategy::fire(const PetriNet& net, uint8_t t, const MarkVal* old_m, MarkVal* new_m){
for(size_t i = 0; i < net.numberOfPlaces(); i++){
new_m[i] = old_m[i] + net.transitionVector(t)[i];
if(new_m[i] < 0)
return false;
}
return true;
}
bool KarpMillerL1SearchStrategy::reachable(const PetriNet &net,
const MarkVal *initialMarking,
const VarVal*,
PQL::Condition *query){
assert(net.numberOfVariables() == 0);
if(net.numberOfVariables() > 0){
//TODO: Return unknown, or could not be found
return false;
}
const unsigned int nTransitions = net.numberOfTransitions(),
nPlaces = net.numberOfPlaces();
MarkVal old_m[nPlaces];
MarkVal new_m[nPlaces];
memcpy(old_m, initialMarking, nPlaces * sizeof(MarkVal));
size_t depth = 1;
uint8_t* stack = new uint8_t[MAX_DEPTH];
stack[0] = 0;
uint8_t t = 0;
while(true){
// Invariant:
// old_m is the current marking
// stack[depth] is where the next transtion goes
// t is the next transition to fire
while(!fire(net, t, old_m, new_m)){
while(++t == nTransitions){
if(--depth == 0) //Pop the stack
return false; //Terminate algorithm, we're done now
// Reverse transition on the stack
t = stack[depth];
for(size_t i = 0; i < nPlaces; i++)
old_m[i] -= net.transitionVector(t)[i];
}
}
//Test if query is satisfied
if(query->evaluate(PQL::EvaluationContext(new_m, NULL)))
return true;
//Check if it's seen
bool seen = false;
size_t d = depth;
while(--d > 0){
seen = true;
const MarkVal* tv = net.transitionVector(stack[d]);
for(size_t i = 0; i < nPlaces; i++){
old_m[i] -= tv[i];
seen &= old_m[i] == new_m[i];
if(!seen) break;
}
if(seen) break;
}
if(seen)
printf("|");
else
printf("%i", (int)t);
fflush(stdout);
memcpy(old_m, new_m, nPlaces * sizeof(MarkVal));
if(!seen){
stack[depth++] = t;
t = 0;
}else{
for(size_t i = 0; i < nPlaces; i++)
old_m[i] -= net.transitionVector(t)[i];
//Pop if needed as long as needed
while(++t == nTransitions){
if(--depth == 0) //Pop the stack
return false; //Terminate algorithm, we're done now
// Reverse transition on the stack
t = stack[depth];
for(size_t i = 0; i < nPlaces; i++)
old_m[i] -= net.transitionVector(t)[i];
}
}
}
}