* src/tgbaalgos/gv04.cc, src/tgbaalgos/gv04.hh: New files, partly
based on Thomas Martinez's src/tgbaalgos/tarjan_on_fly.cc and src/tgbaalgos/tarjan_on_fly.hh former implementation. * src/tgbaalgos/Makefile.am (libtgbaalgos_la_SOURCES, tgbaalgos_HEADERS): Add them. * src/tgbatest/ltl2tgba.cc, src/tgbatest/randtgba.cc: Bind the new algorithm. * src/tgbatest/emptchk.test: Test it.
This commit is contained in:
Alexandre Duret-Lutz
parent
0f15d28fe8
commit
6cce60bed7
7 changed files with 332 additions and 1 deletions
245
src/tgbaalgos/gv04.cc
Normal file
245
src/tgbaalgos/gv04.cc
Normal file
|
|
@ -0,0 +1,245 @@
|
|||
// Copyright (C) 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.
|
||||
|
||||
//#define TRACE
|
||||
|
||||
#include <iostream>
|
||||
#ifdef TRACE
|
||||
#define trace std::cerr
|
||||
#else
|
||||
#define trace while (0) std::cerr
|
||||
#endif
|
||||
|
||||
#include <cassert>
|
||||
#include <utility>
|
||||
#include "tgba/tgba.hh"
|
||||
#include "misc/hash.hh"
|
||||
#include "emptiness.hh"
|
||||
#include "gv04.hh"
|
||||
|
||||
namespace spot
|
||||
{
|
||||
namespace
|
||||
{
|
||||
struct stack_entry
|
||||
{
|
||||
const state* s; // State stored in stack entry.
|
||||
tgba_succ_iterator* nexttr; // Next transition to explore.
|
||||
// (The paper uses lasttr for the
|
||||
// last transition, but nexttr is
|
||||
// easier for our iterators.)
|
||||
int lowlink; // Lowlink value if this entry.
|
||||
int pre; // DFS predecessor.
|
||||
int acc; // Accepting state link.
|
||||
};
|
||||
|
||||
struct gv04: public emptiness_check
|
||||
{
|
||||
// The automata to check.
|
||||
const tgba* a;
|
||||
|
||||
// The unique accepting condition of the automaton \a a,
|
||||
// or bddfalse if there is no.
|
||||
bdd accepting;
|
||||
|
||||
// Map of visited states.
|
||||
typedef Sgi::hash_map<const state*, size_t,
|
||||
state_ptr_hash, state_ptr_equal> hash_type;
|
||||
hash_type h;
|
||||
|
||||
// Stack of visited states on the path.
|
||||
typedef std::vector<stack_entry> stack_type;
|
||||
stack_type stack;
|
||||
size_t max_stack_size;
|
||||
|
||||
int top; // Top of SCC stack.
|
||||
int dftop; // Top of DFS stack.
|
||||
bool violation; // Whether an accepting run was found.
|
||||
|
||||
gv04(const tgba *a)
|
||||
: a(a), accepting(a->all_acceptance_conditions())
|
||||
{
|
||||
assert(a->number_of_acceptance_conditions() <= 1);
|
||||
}
|
||||
|
||||
~gv04()
|
||||
{
|
||||
for (stack_type::iterator i = stack.begin(); i != stack.end(); ++i)
|
||||
delete i->nexttr;
|
||||
hash_type::const_iterator s = h.begin();
|
||||
while (s != h.end())
|
||||
{
|
||||
// Advance the iterator before deleting the "key" pointer.
|
||||
const state* ptr = s->first;
|
||||
++s;
|
||||
delete ptr;
|
||||
}
|
||||
}
|
||||
|
||||
virtual emptiness_check_result*
|
||||
check()
|
||||
{
|
||||
max_stack_size = 0;
|
||||
top = dftop = -1;
|
||||
violation = false;
|
||||
push(a->get_init_state(), false);
|
||||
|
||||
while (!violation && dftop >= 0)
|
||||
{
|
||||
tgba_succ_iterator* iter = stack[dftop].nexttr;
|
||||
|
||||
trace << "Main iteration (top = " << top
|
||||
<< ", dftop = " << dftop
|
||||
<< ", s = " << a->format_state(stack[dftop].s)
|
||||
<< ")" << std::endl;
|
||||
|
||||
if (iter->done())
|
||||
{
|
||||
trace << " No more successors" << std::endl;
|
||||
pop();
|
||||
}
|
||||
else
|
||||
{
|
||||
const state* s_prime = iter->current_state();
|
||||
bool acc = iter->current_acceptance_conditions() == accepting;
|
||||
iter->next();
|
||||
|
||||
trace << " Next successor: s_prime = "
|
||||
<< a->format_state(s_prime)
|
||||
<< (acc ? " (with accepting link)" : "");
|
||||
|
||||
hash_type::const_iterator i = h.find(s_prime);
|
||||
|
||||
if (i == h.end())
|
||||
{
|
||||
trace << " is a new state." << std::endl;
|
||||
push(s_prime, acc);
|
||||
}
|
||||
else
|
||||
{
|
||||
if (i->second < stack.size()
|
||||
&& stack[i->second].s->compare(s_prime) == 0)
|
||||
{
|
||||
// s_prime has a clone on stack
|
||||
trace << " is on stack." << std::endl;
|
||||
// This is an addition to GV04 to support TBA.
|
||||
violation |= acc;
|
||||
lowlinkupdate(dftop, i->second);
|
||||
}
|
||||
else
|
||||
{
|
||||
trace << " has been seen, but is no longer on stack."
|
||||
<< std::endl;
|
||||
}
|
||||
|
||||
delete s_prime;
|
||||
}
|
||||
}
|
||||
}
|
||||
if (violation)
|
||||
return new emptiness_check_result;
|
||||
return 0;
|
||||
}
|
||||
|
||||
void
|
||||
push(const state* s, bool accepting)
|
||||
{
|
||||
trace << " push(s = " << a->format_state(s)
|
||||
<< ", accepting = " << accepting << ")" << std::endl;
|
||||
|
||||
h[s] = ++top;
|
||||
|
||||
tgba_succ_iterator* iter = a->succ_iter(s);
|
||||
iter->first();
|
||||
stack_entry ss = { s, iter, top, dftop, 0 };
|
||||
|
||||
if (accepting)
|
||||
ss.acc = dftop; // This differs from GV04 to support TBA.
|
||||
else if (dftop >= 0)
|
||||
ss.acc = stack[dftop].acc;
|
||||
else
|
||||
ss.acc = -1;
|
||||
|
||||
trace << " s.lowlink = " << top << std::endl;
|
||||
|
||||
stack.push_back(ss);
|
||||
dftop = top;
|
||||
|
||||
max_stack_size = std::max(max_stack_size, stack.size());
|
||||
}
|
||||
|
||||
void
|
||||
pop()
|
||||
{
|
||||
trace << " pop()" << std::endl;
|
||||
|
||||
int p = stack[dftop].pre;
|
||||
if (p >= 0)
|
||||
lowlinkupdate(p, dftop);
|
||||
if (stack[dftop].lowlink == dftop)
|
||||
{
|
||||
assert(static_cast<unsigned int>(top + 1) == stack.size());
|
||||
for (int i = top; i >= dftop; --i)
|
||||
{
|
||||
delete stack[i].nexttr;
|
||||
stack.pop_back();
|
||||
}
|
||||
top = dftop - 1;
|
||||
}
|
||||
dftop = p;
|
||||
}
|
||||
|
||||
void
|
||||
lowlinkupdate(int f, int t)
|
||||
{
|
||||
trace << " lowlinkupdate(f = " << f << ", t = " << t
|
||||
<< ")" << std::endl
|
||||
<< " t.lowlink = " << stack[t].lowlink << std::endl
|
||||
<< " f.lowlink = " << stack[f].lowlink << std::endl;
|
||||
int stack_t_lowlink = stack[t].lowlink;
|
||||
if (stack_t_lowlink <= stack[f].lowlink)
|
||||
{
|
||||
if (stack_t_lowlink <= stack[f].acc)
|
||||
violation = true;
|
||||
stack[f].lowlink = stack_t_lowlink;
|
||||
trace << " f.lowlink updated to "
|
||||
<< stack[f].lowlink << std::endl;
|
||||
}
|
||||
}
|
||||
|
||||
virtual std::ostream&
|
||||
print_stats(std::ostream& os) const
|
||||
{
|
||||
os << h.size() << " unique states visited" << std::endl;
|
||||
os << max_stack_size << " items max on stack" << std::endl;
|
||||
return os;
|
||||
}
|
||||
|
||||
};
|
||||
|
||||
} // anonymous
|
||||
|
||||
emptiness_check*
|
||||
explicit_gv04_check(const tgba* a)
|
||||
{
|
||||
return new gv04(a);
|
||||
}
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue