alarsyo/spot
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

* src/tgbaalgos/magic.cc: rewrite to externalize the heap and

Browse source 
prepare it to a bit state hashing version.
* src/tgbaalgos/magic.hh: adapt to the new interface of
magic_search and se05_search.
* src/tgbaalgos/se05.cc: new file.
* src/tgbaalgos/Makefile.am: Add it.
* src/tgbatest/ltl2tgba.cc: Add new emptiness check.
* src/tgbatest/emptchk.test: more tests.
* src/tgbatest/dfs.test: new file.
* src/tgbatest/Makefile.am: Add it.
This commit is contained in:
Denis Poitrenaud 2004-11-09 17:22:58 +00:00
parent 908b6129f4
commit f52082bcfb
9 changed files with 1226 additions and 254 deletions
Download patch file Download diff file Expand all files Collapse all files

483
src/tgbaalgos/se05.cc Normal file
View file

@ -0,0 +1,483 @@
// Copyright (C) 2003, 2004 Laboratoire d'Informatique de Paris 6 (LIP6),
// département Systèmes Répartis Coopératifs (SRC), Université Pierre
// et Marie Curie.
//
// This file is part of Spot, a model checking library.
//
// Spot is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// Spot 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 Spot; see the file COPYING. If not, write to the Free
// Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
// 02111-1307, USA.
#include <iostream>
#include "misc/hash.hh"
#include <list>
#include <iterator>
#include <cassert>
#include "magic.hh"
namespace spot
{
namespace
{
enum color {WHITE, CYAN, BLUE, RED};
/// \brief Emptiness checker on spot::tgba automata having at most one
/// accepting condition (i.e. a TBA).
template <typename heap>
class se05_search : public emptiness_check
{
public:
/// \brief Initialize the Magic Search algorithm on the automaton \a a
///
/// \pre The automaton \a a must have at most one accepting
/// condition (i.e. it is a TBA).
se05_search(const tgba *a)
: current_weight(0), a(a), all_cond(a->all_acceptance_conditions())
{
assert(a->number_of_acceptance_conditions() <= 1);
}
virtual ~se05_search()
{
// Release all iterators on the stacks.
while (!st_blue.empty())
{
h.pop_notify(st_blue.front().s);
delete st_blue.front().it;
st_blue.pop_front();
}
while (!st_red.empty())
{
h.pop_notify(st_red.front().s);
delete st_red.front().it;
st_red.pop_front();
}
}
/// \brief Perform a Magic Search.
///
/// \return non null pointer iff the algorithm has found a
/// new accepting path.
///
/// check() can be called several times (until it returns a null
/// pointer) to enumerate all the visited accepting paths. The method
/// visits only a finite set of accepting paths.
virtual emptiness_check_result* check()
{
nbn = nbt = 0;
sts = mdp = st_blue.size() + st_red.size();
if (st_red.empty())
{
assert(st_blue.empty());
const state* s0 = a->get_init_state();
++nbn;
h.add_new_state(s0, CYAN);
push(st_blue, s0, bddfalse, bddfalse);
if (dfs_blue())
return new result(*this);
}
else
{
h.pop_notify(st_red.front().s);
delete st_red.front().it;
st_red.pop_front();
if (!st_red.empty() && dfs_red())
return new result(*this);
else
if (dfs_blue())
return new result(*this);
}
return 0;
}
virtual std::ostream& print_stats(std::ostream &os) const
{
os << nbn << " distinct nodes visited" << std::endl;
os << nbt << " transitions explored" << std::endl;
os << mdp << " nodes for the maximal stack depth" << std::endl;
if (!st_red.empty())
{
assert(!st_blue.empty());
os << st_blue.size() + st_red.size() - 1
<< " nodes for the counter example" << std::endl;
}
return os;
}
private:
/// \brief counters for statistics (number of distinct nodes, of
/// transitions and maximal stacks size.
int nbn, nbt, mdp, sts;
struct stack_item
{
stack_item(const state* n, tgba_succ_iterator* i, bdd l, bdd a)
: s(n), it(i), label(l), acc(a) {};
/// The visited state.
const state* s;
/// Design the next successor of \a s which has to be visited.
tgba_succ_iterator* it;
/// The label of the transition followed to reach \a s
/// (false for the first one).
bdd label;
/// The acc set of the transition followed to reach \a s
/// (false for the first one).
bdd acc;
};
typedef std::list<stack_item> stack_type;
void push(stack_type& st, const state* s,
const bdd& label, const bdd& acc)
{
++sts;
if (sts>mdp)
mdp = sts;
tgba_succ_iterator* i = a->succ_iter(s);
i->first();
st.push_front(stack_item(s, i, label, acc));
}
/// \brief Stack of the blue dfs.
stack_type st_blue;
/// \brief number of visited accepting arcs
/// in the blue stack.
int current_weight;
/// \brief Stack of the red dfs.
stack_type st_red;
/// \brief Map where each visited state is colored
/// by the last dfs visiting it.
heap h;
/// The automata to check.
const tgba* a;
/// The automata to check.
bdd all_cond;
bool dfs_blue()
{
while (!st_blue.empty())
{
stack_item& f = st_blue.front();
if (!f.it->done())
{
++nbt;
const state *s_prime = f.it->current_state();
bdd label = f.it->current_condition();
bdd acc = f.it->current_acceptance_conditions();
f.it->next();
typename heap::color_ref c = h.get_color_ref(s_prime);
if (c.is_null())
// Go down the edge (f.s, <label, acc>, s_prime)
{
if (acc == all_cond)
++current_weight;
++nbn;
h.add_new_state(s_prime, CYAN, current_weight);
push(st_blue, s_prime, label, acc);
}
else // Backtrack the edge (f.s, <label, acc>, s_prime)
{
if (c.get() == CYAN &&
(acc == all_cond || current_weight > c.get_weight()))
{
c.set(RED);
push(st_red, s_prime, label, acc);
return true;
}
else if (c.get() == BLUE && acc == all_cond)
{
// the test 'c.get() == BLUE' is added to limit
// the number of runs reported by successive
// calls to the check method. Without this
// functionnality, the test can be ommited.
c.set(RED);
push(st_red, s_prime, label, acc);
if (dfs_red())
return true;
}
}
}
else
// Backtrack the edge
// (predecessor of f.s in st_blue, <f.label, f.acc>, f.s)
{
--sts;
stack_item f_dest(f);
delete f.it;
st_blue.pop_front();
if (f_dest.acc == all_cond)
--current_weight;
typename heap::color_ref c = h.get_color_ref(f_dest.s);
assert(!c.is_null());
if (c.get() == BLUE && f_dest.acc == all_cond
&& !st_blue.empty())
// the test 'c.get() == BLUE' is added to limit
// the number of runs reported by successive
// calls to the check method. Without this
// functionnality, the test can be ommited.
{
c.set(RED);
push(st_red, f_dest.s, f_dest.label, f_dest.acc);
if (dfs_red())
return true;
}
else
{
c.set(BLUE);
h.pop_notify(f_dest.s);
}
}
}
return false;
}
bool dfs_red()
{
assert(!st_red.empty());
while (!st_red.empty())
{
stack_item& f = st_red.front();
if (!f.it->done())
{
++nbt;
const state *s_prime = f.it->current_state();
bdd label = f.it->current_condition();
bdd acc = f.it->current_acceptance_conditions();
f.it->next();
typename heap::color_ref c = h.get_color_ref(s_prime);
if (c.is_null())
// Notice that this case is taken into account only to
// support successive calls to the check method. Without
// this functionnality => assert(c.is_null())
// Go down the edge (f.s, <label, acc>, s_prime)
{
++nbn;
h.add_new_state(s_prime, RED);
push(st_red, s_prime, label, acc);
}
else // Go down the edge (f.s, <label, acc>, s_prime)
{
if (c.get() == CYAN)
{
c.set(RED);
push(st_red, s_prime, label, acc);
return true;
}
if (c.get() == BLUE)
{
c.set(RED);
push(st_red, s_prime, label, acc);
}
}
}
else // Backtrack
{
--sts;
h.pop_notify(f.s);
delete f.it;
st_red.pop_front();
}
}
return false;
}
class result: public emptiness_check_result
{
public:
result(se05_search& ms)
: ms_(ms)
{
}
virtual tgba_run* accepting_run()
{
assert(!ms_.st_blue.empty());
assert(!ms_.st_red.empty());
tgba_run* run = new tgba_run;
typename stack_type::const_reverse_iterator i, j, end;
tgba_run::steps* l;
const state* target = ms_.st_red.front().s;
l = &run->prefix;
i = ms_.st_blue.rbegin();
end = ms_.st_blue.rend(); --end;
j = i; ++j;
for (; i != end; ++i, ++j)
{
if (l == &run->prefix && i->s->compare(target) == 0)
l = &run->cycle;
tgba_run::step s = { i->s->clone(), j->label, j->acc };
l->push_back(s);
}
if (l == &run->prefix && i->s->compare(target) == 0)
l = &run->cycle;
assert(l == &run->cycle);
j = ms_.st_red.rbegin();
tgba_run::step s = { i->s->clone(), j->label, j->acc };
l->push_back(s);
i = j; ++j;
end = ms_.st_red.rend(); --end;
for (; i != end; ++i, ++j)
{
tgba_run::step s = { i->s->clone(), j->label, j->acc };
l->push_back(s);
}
return run;
}
private:
se05_search& ms_;
};
};
class explicit_se05_search_heap
{
typedef Sgi::hash_map<const state*, int,
state_ptr_hash, state_ptr_equal> hcyan_type;
typedef Sgi::hash_map<const state*, color,
state_ptr_hash, state_ptr_equal> hash_type;
public:
class color_ref
{
public:
color_ref(hash_type* h, hcyan_type* hc, const state* s, int w)
: is_cyan(true), weight(w), ph(h), phc(hc), ps(s), pc(0)
{
}
color_ref(color* c)
: is_cyan(false), weight(0), ph(0), phc(0), ps(0), pc(c)
{
}
int get() const
{
if (is_cyan)
return CYAN; // the color cyan is fixed to 0
return *pc;
}
int get_weight() const
{
assert(is_cyan);
return weight;
}
void set(color c)
{
assert(!is_null());
if (is_cyan)
{
phc->erase(ps);
ph->insert(std::make_pair(ps, c));
}
else
{
*pc=c;
}
}
bool is_null() const
{
return !is_cyan && pc==0;
}
private:
bool is_cyan;
int weight; // weight of a cyan node
hash_type* ph; //point to the main hash table
hcyan_type* phc; // point to the hash table hcyan
const state* ps; // point to the state in hcyan
color *pc; // point to the color of a state stored in main hash table
};
explicit_se05_search_heap()
{
}
~explicit_se05_search_heap()
{
hcyan_type::const_iterator sc = hc.begin();
while (sc != hc.end())
{
const state* ptr = sc->first;
++sc;
delete ptr;
}
hash_type::const_iterator s = h.begin();
while (s != h.end())
{
const state* ptr = s->first;
++s;
delete ptr;
}
}
color_ref get_color_ref(const state*& s)
{
hcyan_type::iterator ic = hc.find(s);
if (ic==hc.end())
{
hash_type::iterator it = h.find(s);
if (it==h.end())
return color_ref(0); // unknown state
if (s!=it->first)
{
delete s;
s = it->first;
}
return color_ref(&(it->second)); // blue or red state
}
if (s!=ic->first)
{
delete s;
s = ic->first;
}
return color_ref(&h, &hc, ic->first, ic->second); // cyan state
}
void add_new_state(const state* s, color c, int w=0)
{
assert(hc.find(s)==hc.end() && h.find(s)==h.end());
if (c == CYAN)
hc.insert(std::make_pair(s, w));
else
h.insert(std::make_pair(s, c));
}
void pop_notify(const state*)
{
}
private:
hash_type h;
hcyan_type hc;
};
} // anonymous
emptiness_check* explicit_se05_search(const tgba *a)
{
return new se05_search<explicit_se05_search_heap>(a);
}
}