summaryrefslogtreecommitdiff
path: root/impl/MaxStrategy.hpp
diff options
context:
space:
mode:
Diffstat (limited to 'impl/MaxStrategy.hpp')
-rw-r--r--impl/MaxStrategy.hpp110
1 files changed, 65 insertions, 45 deletions
diff --git a/impl/MaxStrategy.hpp b/impl/MaxStrategy.hpp
index d908c7b..5534597 100644
--- a/impl/MaxStrategy.hpp
+++ b/impl/MaxStrategy.hpp
@@ -9,7 +9,10 @@
template<typename Domain>
struct MaxStrategy {
virtual ~MaxStrategy() { }
- virtual unsigned int get(const MaxExpression<Domain>& e) = 0;
+ virtual unsigned int get(const MaxExpression<Domain>& e) {
+ return const_cast<const MaxStrategy<Domain>*>(this)->get(e);
+ }
+ virtual unsigned int get(const MaxExpression<Domain>& e) const = 0;
};
unsigned int stack_depth = 1;
@@ -39,44 +42,60 @@ struct DynamicMaxStrategy : public MaxStrategy<Domain> {
IdSet<MaxExpression<Domain> >(system.maxExpressionCount())),
_var_influence(system.variableCount(),
IdSet<MaxExpression<Domain> >(system.maxExpressionCount())),
- _frozen(false)
+ _changed(false)
{}
- void freeze() {
- _frozen = true;
+ void setRho(DynamicVariableAssignment<Domain>& rho) {
+ _rho = &rho;
}
- void thaw() {
- _frozen = false;
+ void hasChanged(bool c) {
+ _changed = c;
}
- bool is_frozen() {
- return _frozen;
+ bool hasChanged() const {
+ return _changed;
}
- void setRho(DynamicVariableAssignment<Domain>& rho) {
- _rho = &rho;
+ unsigned int get(const MaxExpression<Domain>& e) const {
+ log::strategy << indent() << "Look up " << e << std::endl;
+ return _values[e];
}
unsigned int get(const MaxExpression<Domain>& e) {
- if (!_frozen)
- solve(e);
+ log::strategy << indent() << "Solve for " << e << std::endl;
+ solve(e);
return _values[e];
}
void invalidate(const Variable<Domain>& v) {
log::strategy << indent() << "Invalidating " << v << " - " << *_system[v] << std::endl;
- _stable.filter(_var_influence[v]);
+ //log::debug << indent() << " var-influence sets " << _var_influence << std::endl;
IdSet<MaxExpression<Domain> > infl = _var_influence[v];
- _var_influence[v].clear();
-
for (typename IdSet<MaxExpression<Domain> >::iterator
it = infl.begin(),
end = infl.end();
it != end;
++it) {
- solve(_system.maxExpression(*it));
+ invalidate(_system.maxExpression(*it));
+ }
+ }
+
+ void invalidate(const MaxExpression<Domain>& v) {
+ if (_stable.contains(v)) {
+ log::strategy << indent() << "Invalidating " << v << std::endl;
+ //log::debug << indent() << " influence sets " << _influence << std::endl;
+ _stable.remove(v);
+
+ IdSet<MaxExpression<Domain> > infl = _influence[v];
+ for (typename IdSet<MaxExpression<Domain> >::iterator
+ it = infl.begin(),
+ end = infl.end();
+ it != end;
+ ++it) {
+ invalidate(_system.maxExpression(*it));
+ }
}
}
@@ -96,16 +115,13 @@ private:
log::strategy << x << " => " << *x.arguments()[val] << std::endl;
IdSet<MaxExpression<Domain> > oldInfluence = _influence[x];
- _influence[x].clear();
+ //_influence[x].clear();
_values[x] = val;
+ _changed = true;
_rho->invalidate(*_system.varFromExpr(x));
-
- _rho->thaw();
- this->freeze();
- _rho->stabilise();
- _rho->freeze();
- this->thaw();
+
+ //_rho->stabilise();
_stable.filter(oldInfluence);
@@ -136,15 +152,11 @@ private:
_current(strat._system.variableCount()) {
}
const Domain operator[](const Variable<Domain>& var) {
+ // solve the strategy for this variable, too
+ _strat.solve(*_strat._system[var]);
_strat._var_influence[var].insert(_expr);
- if (_current.contains(var)) {
- return _rho[var];
- } else {
- _current.insert(var);
- Domain val = _strat._system[var]->eval(_rho, _strat);
- _current.remove(var);
- return val;
- }
+ _strat._influence[*_strat._system[var]].insert(_expr);
+ return _rho[var];
}
private:
DynamicMaxStrategy& _strat;
@@ -158,11 +170,13 @@ private:
: _strat(strat),
_expr(expr) {
}
+ unsigned int get(const MaxExpression<Domain>& e) const {
+ _strat._influence[e].insert(_expr);
+ return _strat._values[e];
+ }
unsigned int get(const MaxExpression<Domain>& e) {
_strat.solve(e);
- if (&_expr != &e) {
- _strat._influence[e].insert(_expr);
- }
+ _strat._influence[e].insert(_expr);
return _strat._values[e];
}
private:
@@ -177,7 +191,7 @@ private:
IdSet<MaxExpression<Domain> > _stable;
IdMap<MaxExpression<Domain>,IdSet<MaxExpression<Domain> > > _influence;
IdMap<Variable<Domain>,IdSet<MaxExpression<Domain> > > _var_influence;
- bool _frozen;
+ bool _changed;
};
@@ -193,19 +207,25 @@ struct Solver {
Domain solve(Variable<Domain>& var) {
MaxExpression<Domain>& rhs = *_system[var];
- do {
- _rho.has_changed(false);
+ // _rho automatically keeps up to date with changes made to the
+ // strategy, so you don't need to stabilise it
+
+ _strategy.get(rhs);
- // improve strategy
- _rho.freeze();
- _strategy.thaw();
- _strategy.get(rhs);
- // iterate fixpoint
- _strategy.freeze();
- _rho.thaw();
+ /*
+ do {
+ _strategy.hasChanged(false);
+
+ log::debug << "Stabilise assignment (toplevel)" << std::endl;
_rho.stabilise();
- } while (_rho.has_changed());
+
+ log::debug << "Improve strategy (toplevel)" << std::endl;
+ // improve strategy
+ _strategy.get(rhs);
+ log::debug << (_strategy.hasChanged() ? "Strategy has changed - loop again" : "Strategy has not changed - terminate") << std::endl;
+ } while (_strategy.hasChanged());
+ */
return _rho[var];
}