choco.prop
Class ChocEngine

java.lang.Object
  choco.AbstractEntity
      choco.prop.AbstractPropagationEngine
          choco.prop.ChocEngine

All Implemented Interfaces:

Entity, PropagationEngine

Direct Known Subclasses:

PalmEngine

public class ChocEngine
extends AbstractPropagationEngine

Implementation of an AbstractPropagationEngine for Choco.

Field Summary

protected static int	NB_CONST_QUEUES the number of queues for storing constraint events
protected int	nbPendingInitConstAwakeEvent Number of pending init constraint awake events.
protected VarEventQueue	varEventQueue The queue with all the variable events.

Fields inherited from class choco.prop.AbstractPropagationEngine

contradictionCause

Fields inherited from class choco.AbstractEntity

hook, problem

Constructor Summary

ChocEngine(AbstractProblem pb)
Constructs a new engine by initializing the var queues.

Method Summary

protected void	_postEvent(Var v, int idx, int basicEvt) Private method for completing the bound var posting.
boolean	checkCleanState() checking that the propagation engine remains in a proper state
void	decPendingInitConstAwakeEvent() Decrements the number of init constraint awake events.
void	flushEvents() Removes all pending events (used when interrupting a propagation because a contradiction has been raised)
int	getNbPendingEvents()
EventQueue	getNextActiveConstraintEventQueue() Returns the next constraint var queue from which an event should be propagated.
EventQueue	getNextActiveEventQueue() Returns the next queue from which an event should be propagated.
PropagationEvent	getPendingEvent(int idx) getter without side effect: returns the i-ht pending event (without popping any event from the queues)
ConstraintEventQueue	getQueue(ConstraintEvent event) Gets the queue for a given priority of var.
VarEventQueue	getVarEventQueue() Returns the variable var queue.
void	incPendingInitConstAwakeEvent() Increments the number of init constraint awake events.
void	postAddKer(SetVar v, int idx) Posts a kernel addition event on a set variable
boolean	postConstAwake(Propagator constraint, boolean init) Posts a constraint awake var.
void	postInstInt(IntDomainVar v, int idx) Posts an Inst var.
void	postInstSet(SetVar v, int idx) Posts an Inst event on a set var.
void	postRemEnv(SetVar v, int idx) Posts a removal event on a set variable
void	postRemoveVal(IntDomainVar v, int x, int idx) Posts an Remove var.
void	postUpdateInf(IntDomainVar v, int idx) Posts an IncInf event
void	postUpdateInf(RealVar v, int idx) Posts an lower bound event for a real variable.
void	postUpdateSup(IntDomainVar v, int idx) Posts a DecSup event
void	postUpdateSup(RealVar v, int idx) Posts an upper bound event for a real variable
void	raiseContradiction() Throws a contradiction without cause.
void	raiseContradiction(Entity cause) Throws a contradiction with the specified cause.
void	registerEvent(ConstraintEvent event) Registers an event in the queue.

Methods inherited from class choco.prop.AbstractPropagationEngine

getContradictionCause, setContradictionCause, setNoContradictionCause

Methods inherited from class choco.AbstractEntity

getProblem, pretty

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface choco.Entity

getProblem, pretty

Field Detail

NB_CONST_QUEUES

protected static int NB_CONST_QUEUES

the number of queues for storing constraint events

nbPendingInitConstAwakeEvent

protected int nbPendingInitConstAwakeEvent

Number of pending init constraint awake events.

varEventQueue

protected VarEventQueue varEventQueue

The queue with all the variable events.

Constructor Detail

ChocEngine

public ChocEngine(AbstractProblem pb)

Constructs a new engine by initializing the var queues.

Method Detail

postUpdateInf

public void postUpdateInf(IntDomainVar v,
                          int idx)

Posts an IncInf event

Parameters:

v - The variable the bound is modified.

idx - The index of the constraint which is responsible of the var.

postUpdateSup

public void postUpdateSup(IntDomainVar v,
                          int idx)

Posts a DecSup event

Parameters:

v - The variable the bound is modified.

idx - The index of the constraint which is responsible of the var.

_postEvent

protected void _postEvent(Var v,
                          int idx,
                          int basicEvt)

Private method for completing the bound var posting.

Parameters:

basicEvt - The basic event posted.

idx - The index of the constraint which is responsible of the var.

postInstInt

public void postInstInt(IntDomainVar v,
                        int idx)

Posts an Inst var.

Parameters:

v - The variable that is instantiated.

idx - The index of the constraint which is responsible of the var.

postRemoveVal

public void postRemoveVal(IntDomainVar v,
                          int x,
                          int idx)

Posts an Remove var.

Parameters:

v - The variable the value is removed from.

idx - The index of the constraint which is responsible of the var.

postUpdateInf

public void postUpdateInf(RealVar v,
                          int idx)

Posts an lower bound event for a real variable.

Parameters:

v -

idx -

postUpdateSup

public void postUpdateSup(RealVar v,
                          int idx)

Posts an upper bound event for a real variable

Parameters:

v -

idx -

postRemEnv

public void postRemEnv(SetVar v,
                       int idx)

Posts a removal event on a set variable

Parameters:

v - the variable the enveloppe is modified

idx - the index of the constraint that causes the event

postAddKer

public void postAddKer(SetVar v,
                       int idx)

Posts a kernel addition event on a set variable

Parameters:

v - the variable the kernel is modified

idx - the index of the constraint that causes the event

postInstSet

public void postInstSet(SetVar v,
                        int idx)

Posts an Inst event on a set var.

Parameters:

v - The variable that is instantiated.

idx - The index of the constraint which is responsible of the var.

postConstAwake

public boolean postConstAwake(Propagator constraint,
                              boolean init)

Posts a constraint awake var.

Parameters:

constraint - The constraint that must be awaken.

init - Specifies if the constraint must be initialized (awake instead of propagate).

getQueue

public ConstraintEventQueue getQueue(ConstraintEvent event)

Gets the queue for a given priority of var.

Parameters:

event - The var for which the queue is searched.

registerEvent

public void registerEvent(ConstraintEvent event)

Registers an event in the queue. It should be called before using the queue to add the var in the available events of the queue.

Parameters:

event -

getVarEventQueue

public VarEventQueue getVarEventQueue()

Returns the variable var queue.

raiseContradiction

public void raiseContradiction()
                        throws ContradictionException

Throws a contradiction without cause.

Throws:

ContradictionException

raiseContradiction

public void raiseContradiction(Entity cause)
                        throws ContradictionException

Throws a contradiction with the specified cause.

Throws:

ContradictionException

decPendingInitConstAwakeEvent

public void decPendingInitConstAwakeEvent()

Decrements the number of init constraint awake events.

incPendingInitConstAwakeEvent

public void incPendingInitConstAwakeEvent()

Increments the number of init constraint awake events.

getNextActiveConstraintEventQueue

public EventQueue getNextActiveConstraintEventQueue()

Returns the next constraint var queue from which an event should be propagated.

getNextActiveEventQueue

public EventQueue getNextActiveEventQueue()

Returns the next queue from which an event should be propagated.

Specified by:

getNextActiveEventQueue in interface PropagationEngine

Overrides:

getNextActiveEventQueue in class AbstractPropagationEngine

getNbPendingEvents

public int getNbPendingEvents()

getPendingEvent

public PropagationEvent getPendingEvent(int idx)

getter without side effect: returns the i-ht pending event (without popping any event from the queues)

flushEvents

public void flushEvents()

Removes all pending events (used when interrupting a propagation because a contradiction has been raised)

checkCleanState

public boolean checkCleanState()

Description copied from interface: PropagationEngine

checking that the propagation engine remains in a proper state