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Heuristics for SCC strength

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Provides 3 heurisitics to compute the strength of an SCC:
inherent, structural and syntactic

* src/tgbaalgos/isweakscc.cc: implementation
* src/tgbaalgos/isweakscc.hh: definition
This commit is contained in:
Etienne Renault 2013-03-06 15:50:37 +01:00 • committed by Alexandre Duret-Lutz
parent b4fbbc9562
commit 450ec22bc3
2 changed files with 148 additions and 5 deletions
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108
src/tgbaalgos/isweakscc.cc
View file

@ -20,6 +20,8 @@
# define SPOT_TGBAALGOS_ISWEAKSCC_CC
#include "cycles.hh"
#include "tgba/tgbaexplicit.hh"
#include "ltlast/formula.hh"
namespace spot
{
@ -62,18 +64,17 @@ namespace spot
}
};
}
bool
is_weak_scc(scc_map& map, unsigned scc)
is_weak_scc(scc_map& map, unsigned scc, bool easydetect)
{
// If no cycle is accepting, the SCC is weak.
if (!map.accepting(scc))
return true;
// If all transitions use all acceptance conditions, the SCC is weak.
if (map.useful_acc_of(scc) ==
bdd_support(map.get_aut()->neg_acceptance_conditions()))
if (easydetect && map.useful_acc_of(scc) ==
bdd_support(map.get_aut()->neg_acceptance_conditions()))
return true;
// If the SCC is accepting, but one cycle is not, the SCC is not
// weak.
@ -82,7 +83,106 @@ namespace spot
return w.result;
}
bool
is_syntactic_weak_scc(const spot::tgba *a, scc_map& map, unsigned scc)
{
const std::list<const spot::state*> states = map.states_of(scc);
std::list<const spot::state*>::const_iterator it;
for (it = states.begin(); it != states.end(); it++)
{
const state_explicit_formula *s =
dynamic_cast<const state_explicit_formula *>(*it);
const ltl::formula *f = dynamic_cast<const ltl::formula*>
(((const tgba_explicit_formula*) a)->get_label(s));
if ((f->is_syntactic_obligation() ||
f->is_syntactic_persistence() ||
f->is_syntactic_safety()))
return true;
}
return false;
}
bool
is_syntactic_terminal_scc(const spot::tgba *a, scc_map& map, unsigned scc)
{
const std::list<const spot::state*> states = map.states_of(scc);
std::list<const spot::state*>::const_iterator it;
for (it = states.begin(); it != states.end(); it++)
{
const state_explicit_formula *s =
dynamic_cast<const state_explicit_formula *>(*it);
const ltl::formula *f = dynamic_cast<const ltl::formula*>
(((const tgba_explicit_formula*) a)->get_label(s));
if (f->is_syntactic_guarantee())
return true;
}
return false;
}
bool
is_weak_heuristic(scc_map& map, unsigned scc)
{
if (!map.accepting (scc))
return true;
if (map.useful_acc_of(scc) ==
bdd_support(map.get_aut()->neg_acceptance_conditions()))
return true;
return false;
}
bool
is_complete_scc(const spot::tgba *a, scc_map& map, unsigned scc)
{
const std::list<const spot::state*> states = map.states_of(scc);
std::list<const spot::state*>::const_iterator it;
for (it = states.begin(); it != states.end(); it++)
{
const state *s = (*it);
tgba_succ_iterator* it = a->succ_iter(s);
it->first();
// No successors cannot be complete
if (it->done())
{
delete it;
return false;
}
bdd sumall = bddfalse;
while (!it->done())
{
const state *next = it->current_state();
unsigned sccnum = map.scc_of_state(next);
// check it's the same scc
if (sccnum == scc)
sumall |= it->current_condition();
next->destroy();
it->next();
}
delete it;
if (sumall != bddtrue)
{
return false;
}
}
return true;
}
bool
is_terminal_heuristic (const tgba *a, scc_map& map, unsigned scc)
{
// If all transitions use all acceptance conditions, the SCC is weak.
if (map.useful_acc_of(scc) ==
bdd_support(map.get_aut()->neg_acceptance_conditions()))
return is_complete_scc(a, map, scc);
return false;
}
}
#endif // SPOT_TGBAALGOS_ISWEAKSCC_CC