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GTA (Generalized Testing Automata) implementation

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* src/ta/ta.cc, src/ta/ta.hh, src/ta/taexplicit.cc,
src/ta/taexplicit.hh, src/ta/taproduct.cc, src/ta/taproduct.hh,
src/taalgos/Makefile.am, src/taalgos/dotty.cc,
src/taalgos/emptinessta.cc, src/taalgos/minimize.cc,
src/taalgos/minimize.hh, src/taalgos/tgba2ta.cc, src/taalgos/tgba2ta.hh,
src/tgbatest/ltl2tgba.cc: changes introduced to add a new form of TA
called GTA (Generalized Testing Automata). GTA is a TA with acceptance-
conditions added on transitions.
This commit is contained in:
Ala-Eddine Ben-Salem 2011-07-05 21:26:22 +02:00 • committed by Alexandre Duret-Lutz
parent c7f4b8e262
commit 83e7f0fa18
14 changed files with 726 additions and 34 deletions
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src/taalgos/tgba2ta.cc Normal file
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// Copyright (C) 2010, 2011 Laboratoire de Recherche et Developpement
// de l Epita (LRDE).
//
// 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 "ltlast/atomic_prop.hh"
#include "ltlast/constant.hh"
#include "tgba/formula2bdd.hh"
#include "misc/bddop.hh"
#include <cassert>
#include "ltlvisit/tostring.hh"
#include <iostream>
#include "tgba/bddprint.hh"
#include "tgbaalgos/gtec/nsheap.hh"
#include <stack>
#include "tgba2ta.hh"
#include "taalgos/statessetbuilder.hh"
using namespace std;
namespace spot
{
ta*
tgba_to_ta(const tgba* tgba_, bdd atomic_propositions_set_,
bool artificial_initial_state_mode,
bool artificial_livelock_accepting_state_mode, bool degeneralized)
{
ta_explicit* ta;
std::stack<state_ta_explicit*> todo;
// build Initial states set:
state* tgba_init_state = tgba_->get_init_state();
if (artificial_initial_state_mode)
{
state_ta_explicit* ta_init_state = new state_ta_explicit(
tgba_init_state->clone(), bddtrue, true);
ta = new spot::ta_explicit(tgba_, tgba_->all_acceptance_conditions(),ta_init_state);
}
else
{
ta = new spot::ta_explicit(tgba_, tgba_->all_acceptance_conditions());
}
bdd tgba_condition = tgba_->support_conditions(tgba_init_state);
bdd satone_tgba_condition;
while ((satone_tgba_condition = bdd_satoneset(tgba_condition,
atomic_propositions_set_, bddtrue)) != bddfalse)
{
tgba_condition -= satone_tgba_condition;
state_ta_explicit* init_state;
if (degeneralized)
{
init_state = new state_ta_explicit(tgba_init_state->clone(),
satone_tgba_condition, true,
((tgba_sba_proxy*) tgba_)->state_is_accepting(tgba_init_state));
}
else
{
init_state = new state_ta_explicit(tgba_init_state->clone(),
satone_tgba_condition, true, false);
}
state_ta_explicit* s = ta->add_state(init_state);
assert(s == init_state);
ta->add_to_initial_states_set(s);
todo.push(init_state);
}
tgba_init_state->destroy();
while (!todo.empty())
{
state_ta_explicit* source = todo.top();
todo.pop();
tgba_succ_iterator* tgba_succ_it = tgba_->succ_iter(
source->get_tgba_state());
for (tgba_succ_it->first(); !tgba_succ_it->done(); tgba_succ_it->next())
{
const state* tgba_state = tgba_succ_it->current_state();
bdd tgba_condition = tgba_succ_it->current_condition();
bdd tgba_acceptance_conditions =
tgba_succ_it->current_acceptance_conditions();
bdd satone_tgba_condition;
while ((satone_tgba_condition = bdd_satoneset(tgba_condition,
atomic_propositions_set_, bddtrue)) != bddfalse)
{
tgba_condition -= satone_tgba_condition;
bdd all_props = bddtrue;
bdd dest_condition;
if (satone_tgba_condition == source->get_tgba_condition())
while ((dest_condition = bdd_satoneset(all_props,
atomic_propositions_set_, bddtrue)) != bddfalse)
{
all_props -= dest_condition;
state_ta_explicit* new_dest;
if (degeneralized)
{
new_dest = new state_ta_explicit(tgba_state->clone(),
dest_condition, false,
((tgba_sba_proxy*) tgba_)->state_is_accepting(
tgba_state));
}
else
{
new_dest = new state_ta_explicit(tgba_state->clone(),
dest_condition, false, false);
}
state_ta_explicit* dest = ta->add_state(new_dest);
if (dest != new_dest)
{
// the state dest already exists in the testing automata
new_dest->get_tgba_state()->destroy();
delete new_dest;
}
else
{
todo.push(dest);
}
ta->create_transition(source, bdd_setxor(
source->get_tgba_condition(),
dest->get_tgba_condition()),
tgba_acceptance_conditions, dest);
}
}
tgba_state->destroy();
}
delete tgba_succ_it;
}
compute_livelock_acceptance_states(ta);
if (artificial_livelock_accepting_state_mode)
{
state_ta_explicit* artificial_livelock_accepting_state =
new state_ta_explicit(ta->get_tgba()->get_init_state(), bddfalse,
false, false, true, 0, true);
add_artificial_livelock_accepting_state(ta,
artificial_livelock_accepting_state);
}
return ta;
}
void
add_artificial_livelock_accepting_state(ta_explicit* testing_automata,
state_ta_explicit* artificial_livelock_accepting_state)
{
state_ta_explicit* artificial_livelock_accepting_state_added =
testing_automata->add_state(artificial_livelock_accepting_state);
// unique artificial_livelock_accepting_state
assert(artificial_livelock_accepting_state_added
== artificial_livelock_accepting_state);
ta::states_set_t states_set = testing_automata->get_states_set();
ta::states_set_t::iterator it;
std::set<bdd, bdd_less_than>* conditions_to_livelock_accepting_states =
new std::set<bdd, bdd_less_than>;
for (it = states_set.begin(); it != states_set.end(); it++)
{
state_ta_explicit* source = static_cast<state_ta_explicit*> (*it);
conditions_to_livelock_accepting_states->clear();
state_ta_explicit::transitions* trans = source->get_transitions();
state_ta_explicit::transitions::iterator it_trans;
if (trans != 0)
for (it_trans = trans->begin(); it_trans != trans->end();)
{
state_ta_explicit* dest = (*it_trans)->dest;
if (dest->is_livelock_accepting_state()
&& !dest->is_accepting_state())
{
conditions_to_livelock_accepting_states->insert(
(*it_trans)->condition);
}
//remove hole successors states
state_ta_explicit::transitions* dest_trans =
(dest)->get_transitions();
bool dest_trans_empty = dest_trans == 0 || dest_trans->empty();
if (dest_trans_empty)
{
source->get_transitions((*it_trans)->condition)->remove(
*it_trans);
delete (*it_trans);
it_trans = trans->erase(it_trans);
}
else
{
it_trans++;
}
}
if (conditions_to_livelock_accepting_states != 0)
{
std::set<bdd, bdd_less_than>::iterator it_conditions;
for (it_conditions
= conditions_to_livelock_accepting_states->begin(); it_conditions
!= conditions_to_livelock_accepting_states->end(); it_conditions++)
{
testing_automata->create_transition(source, (*it_conditions),
artificial_livelock_accepting_state);
}
}
}
delete conditions_to_livelock_accepting_states;
}
namespace
{
typedef std::pair<spot::state*, tgba_succ_iterator*> pair_state_iter;
}
void
compute_livelock_acceptance_states(ta_explicit* testing_automata)
{
// We use five main data in this algorithm:
// * sscc: a stack of strongly stuttering-connected components (SSCC)
scc_stack_ta sscc;
// * arc, a stack of acceptance conditions between each of these SCC,
std::stack<bdd> arc;
// * h: a hash of all visited nodes, with their order,
// (it is called "Hash" in Couvreur's paper)
numbered_state_heap* h =
numbered_state_heap_hash_map_factory::instance()->build(); ///< Heap of visited states.
// * num: the number of visited nodes. Used to set the order of each
// visited node,
int num = 0;
// * todo: the depth-first search stack. This holds pairs of the
// form (STATE, ITERATOR) where ITERATOR is a tgba_succ_iterator
// over the successors of STATE. In our use, ITERATOR should
// always be freed when TODO is popped, but STATE should not because
// it is also used as a key in H.
std::stack<pair_state_iter> todo;
// * init: the set of the depth-first search initial states
std::stack<state*> init_set;
ta::states_set_t::const_iterator it;
ta::states_set_t init_states = testing_automata->get_initial_states_set();
for (it = init_states.begin(); it != init_states.end(); it++)
{
state* init_state = (*it);
init_set.push(init_state);
}
while (!init_set.empty())
{
// Setup depth-first search from initial states.
{
state_ta_explicit* init =
down_cast<state_ta_explicit*> (init_set.top());
init_set.pop();
state_ta_explicit* init_clone = init->clone();
numbered_state_heap::state_index_p h_init = h->find(init_clone);
if (h_init.first)
continue;
h->insert(init_clone, ++num);
sscc.push(num);
arc.push(bddfalse);
sscc.top().is_accepting
= testing_automata->is_accepting_state(init);
tgba_succ_iterator* iter = testing_automata->succ_iter(init);
iter->first();
todo.push(pair_state_iter(init, iter));
}
while (!todo.empty())
{
state* curr = todo.top().first;
numbered_state_heap::state_index_p spi = h->find(curr->clone());
// If we have reached a dead component, ignore it.
if (*spi.second == -1)
{
todo.pop();
continue;
}
// We are looking at the next successor in SUCC.
tgba_succ_iterator* succ = todo.top().second;
// If there is no more successor, backtrack.
if (succ->done())
{
// We have explored all successors of state CURR.
// Backtrack TODO.
todo.pop();
// fill rem with any component removed,
numbered_state_heap::state_index_p spi =
h->index(curr->clone());
assert(spi.first);
sscc.rem().push_front(curr);
// When backtracking the root of an SSCC, we must also
// remove that SSCC from the ROOT stacks. We must
// discard from H all reachable states from this SSCC.
assert(!sscc.empty());
if (sscc.top().index == *spi.second)
{
// removing states
std::list<state*>::iterator i;
bool is_livelock_accepting_sscc = (sscc.top().is_accepting
&& (sscc.rem().size() > 1)) || (sscc.top().condition
== testing_automata->all_acceptance_conditions());
for (i = sscc.rem().begin(); i != sscc.rem().end(); ++i)
{
numbered_state_heap::state_index_p spi = h->index(
(*i)->clone());
assert(spi.first->compare(*i) == 0);
assert(*spi.second != -1);
*spi.second = -1;
if (is_livelock_accepting_sscc)
{//if it is an accepting sscc
//add the state to G (=the livelock-accepting states set)
state_ta_explicit * livelock_accepting_state =
down_cast<state_ta_explicit*> (*i);
livelock_accepting_state->set_livelock_accepting_state(
true);
}
}
assert(!arc.empty());
sscc.pop();
arc.pop();
}
// automata reduction
testing_automata->delete_stuttering_and_hole_successors(curr);
delete succ;
// Do not delete CURR: it is a key in H.
continue;
}
// Fetch the values destination state we are interested in...
state* dest = succ->current_state();
bdd acc_cond = succ->current_acceptance_conditions();
// ... and point the iterator to the next successor, for
// the next iteration.
succ->next();
// We do not need SUCC from now on.
// Are we going to a new state through a stuttering transition?
bool is_stuttering_transition =
testing_automata->get_state_condition(curr)
== testing_automata->get_state_condition(dest);
state* dest_clone = dest->clone();
spi = h->find(dest_clone);
// Is this a new state?
if (!spi.first)
{
if (!is_stuttering_transition)
{
init_set.push(dest);
dest_clone->destroy();
continue;
}
// Number it, stack it, and register its successors
// for later processing.
h->insert(dest_clone, ++num);
sscc.push(num);
arc.push(acc_cond);
sscc.top().is_accepting = testing_automata->is_accepting_state(
dest);
tgba_succ_iterator* iter = testing_automata->succ_iter(dest);
iter->first();
todo.push(pair_state_iter(dest, iter));
continue;
}
// If we have reached a dead component, ignore it.
if (*spi.second == -1)
continue;
if (!curr->compare(dest))
{
state_ta_explicit * self_loop_state =
down_cast<state_ta_explicit*> (curr);
assert(self_loop_state);
if (testing_automata->is_accepting_state(self_loop_state))
self_loop_state->set_livelock_accepting_state(true);
}
// Now this is the most interesting case. We have reached a
// state S1 which is already part of a non-dead SSCC. Any such
// non-dead SSCC has necessarily been crossed by our path to
// this state: there is a state S2 in our path which belongs
// to this SSCC too. We are going to merge all states between
// this S1 and S2 into this SSCC.
//
// This merge is easy to do because the order of the SSCC in
// ROOT is ascending: we just have to merge all SSCCs from the
// top of ROOT that have an index greater to the one of
// the SSCC of S2 (called the "threshold").
int threshold = *spi.second;
std::list<state*> rem;
bool acc = false;
while (threshold < sscc.top().index)
{
assert(!sscc.empty());
assert(!arc.empty());
acc |= sscc.top().is_accepting;
acc_cond |= sscc.top().condition;
acc_cond |= arc.top();
rem.splice(rem.end(), sscc.rem());
sscc.pop();
arc.pop();
}
// Note that we do not always have
// threshold == sscc.top().index
// after this loop, the SSCC whose index is threshold might have
// been merged with a lower SSCC.
// Accumulate all acceptance conditions into the merged SSCC.
sscc.top().is_accepting |= acc;
sscc.top().condition |= acc_cond;
sscc.rem().splice(sscc.rem().end(), rem);
}
}
delete h;
}
}