Commit f52082bc authored by Denis Poitrenaud's avatar Denis Poitrenaud
Browse files

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

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.
parent 908b6129
2004-11-09 Poitrenaud Denis <denis@src.lip6.fr>
* src/tgbaalgos/magic.cc: rewrite to externalize the heap and
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.
2004-11-09 Alexandre Duret-Lutz <adl@src.lip6.fr>
* src/tgbaalgos/emptiness.cc (print_tgba_run): Output the
......
......@@ -62,6 +62,7 @@ libtgbaalgos_la_SOURCES = \
replayrun.cc \
rundotdec.cc \
save.cc \
se05.cc \
stats.cc \
reductgba_sim.cc \
reductgba_sim_del.cc
......
......@@ -19,163 +19,397 @@
// 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"
#include "tgba/bddprint.hh"
namespace spot
{
magic_search::result::result(magic_search& ms)
: ms_(ms)
namespace
{
}
enum color {WHITE, BLUE, RED};
tgba_run*
magic_search::result::accepting_run()
/// \brief Emptiness checker on spot::tgba automata having at most one
/// accepting condition (i.e. a TBA).
template <typename heap>
class magic_search : public emptiness_check
{
tgba_run* run = new tgba_run;
stack_type::const_reverse_iterator i, e = ms_.stack.rend();
tstack_type::const_reverse_iterator ti;
tgba_run::steps* l = &run->prefix;
for (i = ms_.stack.rbegin(), ti = ms_.tstack.rbegin(); i != e; ++i, ++ti)
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).
magic_search(const tgba *a)
: a(a), all_cond(a->all_acceptance_conditions())
{
if (i->first.s->compare(ms_.x) == 0)
l = &run->cycle;
tgba_run::step s = { i->first.s->clone(), ti->first, ti->second };
l->push_back(s);
assert(a->number_of_acceptance_conditions() <= 1);
}
return run;
virtual ~magic_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();
}
magic_search::magic_search(const tgba_tba_proxy* a)
: a(a), x(0)
while (!st_red.empty())
{
h.pop_notify(st_red.front().s);
delete st_red.front().it;
st_red.pop_front();
}
}
magic_search::~magic_search()
/// \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()
{
hash_type::const_iterator s = h.begin();
while (s != h.end())
nbn = nbt = 0;
sts = mdp = st_blue.size() + st_red.size();
if (st_red.empty())
{
// Advance the iterator before deleting the "key" pointer.
const state* ptr = s->first;
++s;
delete ptr;
assert(st_blue.empty());
const state* s0 = a->get_init_state();
++nbn;
h.add_new_state(s0, BLUE);
push(st_blue, s0, bddfalse, bddfalse);
if (dfs_blue())
return new result(*this);
}
delete x;
// Release all iterators on the stack.
while (!stack.empty())
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())
{
delete stack.front().second;
stack.pop_front();
assert(!st_blue.empty());
os << st_blue.size() + st_red.size() - 1
<< " nodes for the counter example" << std::endl;
}
return os;
}
void
magic_search::push(const state* s, bool m)
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 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;
hash_type::iterator hi = h.find(s);
if (hi == h.end())
/// State targeted by the red dfs.
const state* target;
/// The automata to check.
const tgba* a;
/// The automata to check.
bdd all_cond;
bool dfs_blue()
{
while (!st_blue.empty())
{
magic d = { !m, m };
h[s] = d;
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)
{
++nbn;
h.add_new_state(s_prime, BLUE);
push(st_blue, s_prime, label, acc);
}
else // Backtrack the edge (f.s, <label, acc>, s_prime)
{
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.
{
target = f.s;
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)
{
hi->second.seen_without |= !m;
hi->second.seen_with |= m;
if (hi->first != s)
delete s;
s = hi->first;
--sts;
stack_item f_dest(f);
delete f.it;
st_blue.pop_front();
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.
{
target = st_blue.front().s;
c.set(RED);
push(st_red, f_dest.s, f_dest.label, f_dest.acc);
if (dfs_red())
return true;
}
magic_state ms = { s, m };
stack.push_front(state_iter_pair(ms, i));
else
h.pop_notify(f_dest.s);
}
}
return false;
}
bool
magic_search::has(const state* s, bool m) const
bool dfs_red()
{
hash_type::const_iterator i = h.find(s);
if (i == h.end())
return false;
if (!m && i->second.seen_without)
assert(!st_red.empty());
if (target->compare(st_red.front().s) == 0)
return true;
if (m && i->second.seen_with)
while (!st_red.empty())
{
stack_item& f = st_red.front();
if (!f.it->done()) // Go down
{
++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, one can check 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() != RED)
{
c.set(RED);
push(st_red, s_prime, label, acc);
if (target->compare(s_prime) == 0)
return true;
}
}
}
else // Backtrack
{
--sts;
h.pop_notify(f.s);
delete f.it;
st_red.pop_front();
}
}
return false;
}
emptiness_check_result*
magic_search::check()
class result: public emptiness_check_result
{
if (stack.empty())
// It's a new search.
push(a->get_init_state(), false);
else
// Remove the transition to the cycle root.
tstack.pop_front();
public:
result(magic_search& ms)
: ms_(ms)
{
}
virtual tgba_run* accepting_run()
{
assert(!ms_.st_blue.empty());
assert(!ms_.st_red.empty());
assert(stack.size() == 1 + tstack.size());
tgba_run* run = new tgba_run;
typename stack_type::const_reverse_iterator i, j, end;
tgba_run::steps* l;
while (!stack.empty())
l = &run->prefix;
i = ms_.st_blue.rbegin();
end = ms_.st_blue.rend(); --end;
j = i; ++j;
for (; i != end; ++i, ++j)
{
recurse:
magic_search::state_iter_pair& p = stack.front();
tgba_succ_iterator* i = p.second;
const bool magic = p.first.m;
tgba_run::step s = { i->s->clone(), j->label, j->acc };
l->push_back(s);
}
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:
magic_search& ms_;
};
};
while (!i->done())
class explicit_magic_search_heap
{
const state* s_prime = i->current_state();
bdd c = i->current_condition();
bdd acc = i->current_acceptance_conditions();
i->next();
if (magic && 0 == s_prime->compare(x))
public:
class color_ref
{
public:
color_ref(color* c) :p(c)
{
delete s_prime;
tstack.push_front (tstack_item(c, acc));
assert(stack.size() == tstack.size());
return new result(*this);
}
if (!has(s_prime, magic))
int get() const
{
push(s_prime, magic);
tstack.push_front (tstack_item(c, acc));
goto recurse;
return *p;
}
delete s_prime;
void set(color c)
{
assert(!is_null());
*p=c;
}
bool is_null() const
{
return p==0;
}
private:
color *p;
};
const state* s = p.first.s;
delete i;
stack.pop_front();
explicit_magic_search_heap()
{
}
if (!magic && a->state_is_accepting(s))
~explicit_magic_search_heap()
{
if (!has(s, true))
hash_type::const_iterator s = h.begin();
while (s != h.end())
{
delete x;
x = s->clone();
push(s, true);
continue;
// Advance the iterator before deleting the "key" pointer.
const state* ptr = s->first;
++s;
delete ptr;
}
}
if (!stack.empty())
tstack.pop_front();
color_ref get_color_ref(const state*& s)
{
hash_type::iterator it = h.find(s);
if (it==h.end())
return color_ref(0);
if (s!=it->first)
{
delete s;
s = it->first;
}
return color_ref(&(it->second));
}
assert(tstack.empty());
return 0;
void add_new_state(const state* s, color c)
{
assert(h.find(s)==h.end());
h.insert(std::make_pair(s, c));
}
void pop_notify(const state*)
{
}
private:
typedef Sgi::hash_map<const state*, color,
state_ptr_hash, state_ptr_equal> hash_type;
hash_type h;
};
} // anonymous
emptiness_check* explicit_magic_search(const tgba *a)
{
return new magic_search<explicit_magic_search_heap>(a);
}
}
......@@ -22,107 +22,148 @@
#ifndef SPOT_TGBAALGOS_MAGIC_HH
# define SPOT_TGBAALGOS_MAGIC_HH
#include "misc/hash.hh"
#include <list>
#include <utility>
#include <ostream>
#include "tgba/tgbatba.hh"
#include "tgba/tgba.hh"
#include "emptiness.hh"
namespace spot
{
/// \brief Emptiness check on spot::tgba_tba_proxy automata using
/// the Magic Search algorithm.
/// \brief Returns an emptiness check on the spot::tgba automaton \a a.
///
/// \pre The automaton \a a must have at most one accepting condition (i.e.
/// it is a TBA).
///
/// The method \a check() of the returned checker 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.
///
/// The implemented algorithm is the following.
///
/// \verbatim
/// procedure nested_dfs ()
/// begin
/// call dfs_blue(s0);
/// end;
///
/// procedure dfs_blue (s)
/// begin
/// s.color = blue;
/// for all t in post(s) do
/// if t.color == white then
/// call dfs_blue(t);
/// end if;
/// if (the edge (s,t) is accepting) then
/// target = s;
/// call dfs_red(t);
/// end if;
/// end for;
/// end;
///
/// procedure dfs_red(s)
/// begin
/// s.color = red;
/// if s == target then
/// report cycle
/// end if;
/// for all t in post(s) do
/// if t.color != red then
/// call dfs_red(t);
/// end if;
/// end for;
/// end;
/// \endverbatim
///
/// It is an adaptation to TBA of the Magic Search algorithm
/// which deals with accepting states and is presented in
///
/// This algorithm comes from
/// \verbatim
/// @InProceedings{ godefroid.93.pstv,
/// author = {Patrice Godefroid and Gerard .J. Holzmann},
/// title = {On the verification of temporal properties},
/// booktitle = {Proceedings of the 13th IFIP TC6/WG6.1 International
/// Symposium on Protocol Specification, Testing, and
/// Verification (PSTV'93)},
/// month = {May},
/// editor = {Andr{\'e} A. S. Danthine and Guy Leduc
/// and Pierre Wolper},
/// address = {Liege, Belgium},
/// pages = {109--124},
/// publisher = {North-Holland},
/// year = {1993},
/// series = {IFIP Transactions},
/// volume = {C-16},
/// isbn = {0-444-81648-8}
/// Article{ courcoubertis.92.fmsd,
/// author = {Costas Courcoubetis and Moshe Y. Vardi and Pierre
/// Wolper and Mihalis Yannakakis},
/// title = {Memory-Efficient Algorithm for the Verification of
/// Temporal Properties},
/// journal = {Formal Methods in System Design},
/// pages = {275--288},
/// year = {1992},
/// volume = {1}
/// }
/// \endverbatim
struct magic_search : public emptiness_check