You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 

256 lines
6.9 KiB

/*
* This file is part of the program ltl2dstar (http://www.ltl2dstar.de/).
* Copyright (C) 2005-2007 Joachim Klein <j.klein@ltl2dstar.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef NBASTUTTERCLOSURE_HPP
#define NBASTUTTERCLOSURE_HPP
/** @file
* Provides NBAStutterClosure.
*/
#include "GraphAlgorithms.hpp"
#include "NBAAnalysis.hpp"
#include "APElement.hpp"
#include <memory>
/**
* Calculate the stutter closure for an NBA.
*/
class NBAStutterClosure {
public:
/** Calculate the stutter closure for the NBA, for all symbols.
* @param nba the NBA
*/
template<typename NBA_t>
static std::shared_ptr<NBA_t> stutter_closure(NBA_t& nba) {
APSet_cp apset=nba.getAPSet_cp();
std::shared_ptr<NBA_t> nba_result_ptr(new NBA_t(apset));
NBA_t& result=*nba_result_ptr;
unsigned int element_count=apset->powersetSize();
assert(nba.getStartState());
unsigned int start_state=nba.getStartState()->getName();
for (unsigned int i=0;i<nba.size();i++) {
unsigned int st=result.nba_i_newState();
assert(st==i);
if (st==start_state) {
result.setStartState(result[st]);
}
if (nba[st]->isFinal()) {
result[st]->setFinal(true);
}
}
for (unsigned int i=0;i<nba.size();i++) {
for (unsigned int j=0;j<element_count;j++) {
unsigned int st=result.nba_i_newState();
assert( st == nba.size() + (i*element_count)+j);
result[st]->addEdge(j, *(result[i]));
result[st]->addEdge(j, *(result[st]));
}
}
std::vector< std::vector<BitSet>* > reachable;
reachable.resize(element_count);
for (unsigned int j=0; j<element_count; j++) {
NBAEdgeSuccessors<NBA_t> edge_successor(j);
SCCs scc;
GraphAlgorithms<NBA_t, NBAEdgeSuccessors<NBA_t> >::calculateSCCs(nba,
scc,
true,
edge_successor);
reachable[j]=scc.getReachabilityForAllStates();
#ifdef VERBOSE
std::cerr << "SCCs for " << APElement(j).toString(*apset) << std::endl;
std::cerr << scc << std::endl;
std::cerr << " Reachability: "<< std::endl;
std::vector<BitSet>& reach=*reachable[j];
for (unsigned int t=0; t < reach.size(); t++) {
std::cerr << t << " -> " << reach[t] << std::endl;
}
std::cerr << " ---\n";
#endif
}
for (unsigned int i=0;i<nba.size();i++) {
typename NBA_t::state_type* from=result[i];
for (unsigned int j=0;j<element_count;j++) {
BitSet result_to;
BitSet* to=nba[i]->getEdge(j);
for (BitSetIterator it=BitSetIterator(*to);
it!=BitSetIterator::end(*to);
++it) {
unsigned int to_state=*it;
// We can go directly to the original state
result_to.set(to_state);
// We can also go to the corresponding stutter state instead
unsigned int stutter_state=nba.size() + (to_state*element_count)+j;
result_to.set(stutter_state);
// ... and then we can go directly to all the states that are j-reachable from to
result_to.Union((*(reachable[j]))[to_state]);
}
*(from->getEdge(j)) = result_to;
}
}
for (unsigned int i=0;
i<reachable.size();
++i) {
delete reachable[i];
}
return nba_result_ptr;
}
/** Calculate the stutter closure for the NBA, for a certain symbol.
* @param nba the NBA
* @param label the symbol for which to perform the stutter closure
*/
template<typename NBA_t>
static std::shared_ptr<NBA_t> stutter_closure(NBA_t& nba, APElement label) {
APSet_cp apset=nba.getAPSet_cp();
std::shared_ptr<NBA_t> nba_result_ptr(new NBA_t(apset));
NBA_t& result=*nba_result_ptr;
unsigned int element_count=apset->powersetSize();
assert(nba.getStartState());
unsigned int start_state=nba.getStartState()->getName();
for (unsigned int i=0;i<nba.size();i++) {
unsigned int st=result.nba_i_newState();
assert(st==i);
if (st==start_state) {
result.setStartState(result[st]);
}
if (nba[st]->isFinal()) {
result[st]->setFinal(true);
}
}
for (unsigned int i=0;i<nba.size();i++) {
unsigned int st=result.nba_i_newState();
assert( st == nba.size() + i);
result[st]->addEdge(label, *(result[i]));
result[st]->addEdge(label, *(result[st]));
}
std::vector<BitSet>* reachable;
NBAEdgeSuccessors<NBA_t> edge_successor(label);
SCCs scc;
GraphAlgorithms<NBA_t, NBAEdgeSuccessors<NBA_t> >::calculateSCCs(nba,
scc,
true,
edge_successor);
reachable=scc.getReachabilityForAllStates();
// std::cerr << "SCCs for " << label.toString(*apset) << std::endl;
// std::cerr << scc << std::endl;
// std::cerr << " Reachability: "<< std::endl;
// for (unsigned int t=0; t < reachable->size(); t++) {
// std::cerr << t << " -> " << (*reachable)[t] << std::endl;
// }
// std::cerr << " ---\n";
for (unsigned int i=0;i<nba.size();i++) {
typename NBA_t::state_type* from=result[i];
for (unsigned int j=0;j<element_count;j++) {
BitSet result_to;
BitSet* to=nba[i]->getEdge(j);
if (j!=label) {
result_to=*to;
} else {
for (BitSetIterator it=BitSetIterator(*to);
it!=BitSetIterator::end(*to);
++it) {
unsigned int to_state=*it;
// We can go directly to the original state
result_to.set(to_state);
// We can also go to the corresponding stutter state instead
unsigned int stutter_state=nba.size() + to_state;
result_to.set(stutter_state);
// ... and then we can go directly to all the states that are j-reachable from to
result_to.Union((*reachable)[to_state]);
}
}
*(from->getEdge(j)) = result_to;
}
}
delete reachable;
return nba_result_ptr;
}
private:
/** The successors reachable via a certain label */
template <typename NBA_t>
class NBAEdgeSuccessors {
public:
typedef BitSetIterator successor_iterator;
NBAEdgeSuccessors(APElement label) : _label(label) {};
successor_iterator begin(NBA_t& graph, unsigned int v) {
return BitSetIterator(*(graph[v]->getEdge(_label)));
}
successor_iterator end(NBA_t& graph, unsigned int v) {
return BitSetIterator::end(*(graph[v]->getEdge(_label)));
}
private:
APElement _label;
};
};
#endif