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#include "ReducingSuccessorGenerator.h"
#include <assert.h>
#include "PQL/Contexts.h"
namespace PetriEngine {
ReducingSuccessorGenerator::ReducingSuccessorGenerator(const PetriNet& net) : SuccessorGenerator(net), _inhibpost(net._nplaces){
_current = 0;
_enabled = new bool[net._ntransitions];
_stubborn = new bool[net._ntransitions];
_dependency = new uint32_t[net._ntransitions];
_places_seen.reset(new uint8_t[_net.numberOfPlaces()]);
reset();
constructPrePost();
constructDependency();
checkForInhibitor();
}
ReducingSuccessorGenerator::ReducingSuccessorGenerator(const PetriNet& net, std::vector<std::shared_ptr<PQL::Condition> >& queries) : ReducingSuccessorGenerator(net) {
_queries.reserve(queries.size());
for(auto& q : queries)
_queries.push_back(q.get());
}
ReducingSuccessorGenerator::~ReducingSuccessorGenerator() {
delete [] _enabled;
delete [] _stubborn;
delete [] _dependency;
}
void ReducingSuccessorGenerator::checkForInhibitor(){
_netContainsInhibitorArcs=false;
for (uint32_t t = 0; t < _net._ntransitions; t++) {
const TransPtr& ptr = _net._transitions[t];
uint32_t finv = ptr.inputs;
uint32_t linv = ptr.outputs;
for (; finv < linv; finv++) { // Post set of places
if (_net._invariants[finv].inhibitor) {
_netContainsInhibitorArcs=true;
return;
}
}
}
}
void ReducingSuccessorGenerator::constructPrePost() {
std::vector<std::pair<std::vector<trans_t>, std::vector < trans_t>>> tmp_places(_net._nplaces);
for (uint32_t t = 0; t < _net._ntransitions; t++) {
const TransPtr& ptr = _net._transitions[t];
uint32_t finv = ptr.inputs;
uint32_t linv = ptr.outputs;
for (; finv < linv; finv++) { // Post set of places
if (_net._invariants[finv].inhibitor) {
_inhibpost[_net._invariants[finv].place].push_back(t);
_netContainsInhibitorArcs=true;
} else {
tmp_places[_net._invariants[finv].place].second.emplace_back(t, _net._invariants[finv].direction);
}
}
finv = linv;
linv = _net._transitions[t + 1].inputs;
for (; finv < linv; finv++) { // Pre set of places
if(_net._invariants[finv].direction > 0)
tmp_places[_net._invariants[finv].place].first.emplace_back(t, _net._invariants[finv].direction);
}
}
// flatten
size_t ntrans = 0;
for (auto p : tmp_places) {
ntrans += p.first.size() + p.second.size();
}
_transitions.reset(new trans_t[ntrans]);
_places.reset(new place_t[_net._nplaces + 1]);
uint32_t offset = 0;
uint32_t p = 0;
for (; p < _net._nplaces; ++p) {
auto& pre = tmp_places[p].first;
auto& post = tmp_places[p].second;
// keep things nice for caches
std::sort(pre.begin(), pre.end());
std::sort(post.begin(), post.end());
_places.get()[p].pre = offset;
offset += pre.size();
_places.get()[p].post = offset;
offset += post.size();
for (size_t tn = 0; tn < pre.size(); ++tn) {
_transitions.get()[tn + _places.get()[p].pre] = pre[tn];
}
for (size_t tn = 0; tn < post.size(); ++tn) {
_transitions.get()[tn + _places.get()[p].post] = post[tn];
}
}
assert(offset == ntrans);
_places.get()[p].pre = offset;
_places.get()[p].post = offset;
}
void ReducingSuccessorGenerator::constructDependency() {
memset(_dependency, 0, sizeof(uint32_t) * _net._ntransitions);
for (uint32_t t = 0; t < _net._ntransitions; t++) {
uint32_t finv = _net._transitions[t].inputs;
uint32_t linv = _net._transitions[t].outputs;
for (; finv < linv; finv++) {
const Invariant& inv = _net._invariants[finv];
uint32_t p = inv.place;
uint32_t ntrans = (_places.get()[p + 1].pre - _places.get()[p].post);
for (uint32_t tIndex = 0; tIndex < ntrans; tIndex++) {
_dependency[t]++;
}
}
}
}
void ReducingSuccessorGenerator::constructEnabled() {
_ordering.clear();
for (uint32_t p = 0; p < _net._nplaces; ++p) {
// orphans are currently under "place 0" as a special case
if (p == 0 || (*_parent).marking()[p] > 0) {
uint32_t t = _net._placeToPtrs[p];
uint32_t last = _net._placeToPtrs[p + 1];
for (; t != last; ++t) {
if (!checkPreset(t)) continue;
_enabled[t] = true;
_ordering.push_back(t);
}
}
}
}
bool ReducingSuccessorGenerator::seenPre(uint32_t place) const
{
return (_places_seen.get()[place] & 1) != 0;
}
bool ReducingSuccessorGenerator::seenPost(uint32_t place) const
{
return (_places_seen.get()[place] & 2) != 0;
}
void ReducingSuccessorGenerator::presetOf(uint32_t place, bool make_closure) {
if((_places_seen.get()[place] & 1) != 0) return;
_places_seen.get()[place] = _places_seen.get()[place] | 1;
for (uint32_t t = _places.get()[place].pre; t < _places.get()[place].post; t++)
{
auto& tr = _transitions.get()[t];
addToStub(tr.index);
}
if(make_closure) closure();
}
void ReducingSuccessorGenerator::postsetOf(uint32_t place, bool make_closure) {
if((_places_seen.get()[place] & 2) != 0) return;
_places_seen.get()[place] = _places_seen.get()[place] | 2;
for (uint32_t t = _places.get()[place].post; t < _places.get()[place + 1].pre; t++) {
auto tr = _transitions.get()[t];
if(tr.direction < 0)
addToStub(tr.index);
}
if(make_closure) closure();
}
void ReducingSuccessorGenerator::addToStub(uint32_t t)
{
if(!_stubborn[t])
{
_stubborn[t] = true;
_unprocessed.push_back(t);
}
}
void ReducingSuccessorGenerator::inhibitorPostsetOf(uint32_t place){
if((_places_seen.get()[place] & 4) != 0) return;
_places_seen.get()[place] = _places_seen.get()[place] | 4;
for(uint32_t& newstub : _inhibpost[place])
addToStub(newstub);
}
void ReducingSuccessorGenerator::postPresetOf(uint32_t t, bool make_closure) {
const TransPtr& ptr = _net._transitions[t];
uint32_t finv = ptr.inputs;
uint32_t linv = ptr.outputs;
for (; finv < linv; finv++) { // pre-set of t
if(_net._invariants[finv].inhibitor){
presetOf(_net._invariants[finv].place, make_closure);
} else {
postsetOf(_net._invariants[finv].place, make_closure);
}
}
}
void ReducingSuccessorGenerator::prepare(const Structures::State* state) {
_parent = state;
memset(_places_seen.get(), 0, _net.numberOfPlaces());
constructEnabled();
if(_ordering.size() == 0) return;
if(_ordering.size() == 1)
{
_stubborn[_ordering.front()] = true;
return;
}
for (auto &q : _queries) {
q->evalAndSet(PQL::EvaluationContext((*_parent).marking(), &_net));
q->findInteresting(*this, false);
}
closure();
}
void ReducingSuccessorGenerator::closure()
{
while (!_unprocessed.empty()) {
uint32_t tr = _unprocessed.front();
_unprocessed.pop_front();
const TransPtr& ptr = _net._transitions[tr];
uint32_t finv = ptr.inputs;
uint32_t linv = ptr.outputs;
if(_enabled[tr]){
for (; finv < linv; finv++) {
if(_net._invariants[finv].direction < 0)
{
auto place = _net._invariants[finv].place;
for (uint32_t t = _places.get()[place].post; t < _places.get()[place + 1].pre; t++)
addToStub(_transitions.get()[t].index);
}
}
if(_netContainsInhibitorArcs){
uint32_t next_finv = _net._transitions[tr+1].inputs;
for (; linv < next_finv; linv++)
{
if(_net._invariants[linv].direction > 0)
inhibitorPostsetOf(_net._invariants[finv].place);
}
}
} else {
bool ok = false;
bool inhib = false;
uint32_t cand = std::numeric_limits<uint32_t>::max();
// Lets try to see if we havent already added sufficient pre/post
// for this transition.
for (; finv < linv; ++finv) {
const Invariant& inv = _net._invariants[finv];
if ((*_parent).marking()[inv.place] < inv.tokens && !inv.inhibitor) {
inhib = false;
ok = (_places_seen.get()[inv.place] & 1) != 0;
cand = inv.place;
} else if ((*_parent).marking()[inv.place] >= inv.tokens && inv.inhibitor) {
inhib = true;
ok = (_places_seen.get()[inv.place] & 2) != 0;
cand = inv.place;
}
if(ok) break;
}
// OK, we didnt have sufficient, we just pick whatever is left
// in cand.
assert(cand != std::numeric_limits<uint32_t>::max());
if(!ok && cand != std::numeric_limits<uint32_t>::max())
{
if(!inhib) presetOf(cand);
else postsetOf(cand);
}
}
}
}
bool ReducingSuccessorGenerator::next(Structures::State& write) {
while (!_ordering.empty()) {
_current = _ordering.front();
_ordering.pop_front();
if (_stubborn[_current]) {
assert(_enabled[_current]);
memcpy(write.marking(), (*_parent).marking(), _net._nplaces*sizeof(MarkVal));
consumePreset(write, _current);
producePostset(write, _current);
return true;
}
}
reset();
return false;
}
uint32_t ReducingSuccessorGenerator::leastDependentEnabled() {
uint32_t tLeast = -1;
bool foundLeast = false;
for (uint32_t t = 0; t < _net._ntransitions; t++) {
if (_enabled[t]) {
if (!foundLeast) {
tLeast = t;
foundLeast = true;
} else {
if (_dependency[t] < _dependency[tLeast]) {
tLeast = t;
}
}
}
}
return tLeast;
}
void ReducingSuccessorGenerator::reset() {
SuccessorGenerator::reset();
memset(_enabled, false, sizeof(bool) * _net._ntransitions);
memset(_stubborn, false, sizeof(bool) * _net._ntransitions);
}
}
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