org.optaplanner.core.impl.solver.termination

Interface Termination

All Superinterfaces:

EventListener, PhaseLifecycleListener, SolverLifecycleListener

All Known Implementing Classes:

AbstractCompositeTermination, AbstractTermination, AndCompositeTermination, BasicPlumbingTermination, BestScoreFeasibleTermination, BestScoreTermination, ChildThreadPlumbingTermination, OrCompositeTermination, PhaseToSolverTerminationBridge, ScoreCalculationCountTermination, StepCountTermination, TimeMillisSpentTermination, UnimprovedStepCountTermination, UnimprovedTimeMillisSpentScoreDifferenceThresholdTermination, UnimprovedTimeMillisSpentTermination

public interface Termination
extends PhaseLifecycleListener

A Termination determines when a Solver or a Phase should stop.

An implementation must extend AbstractTermination to ensure backwards compatibility in future versions.

See Also:

AbstractTermination

Method Summary

Modifier and Type	Method and Description
double	calculatePhaseTimeGradient(AbstractPhaseScope phaseScope) See calculateSolverTimeGradient(DefaultSolverScope).
double	calculateSolverTimeGradient(DefaultSolverScope solverScope) A timeGradient is a relative estimate of how long the search will continue.
Termination	createChildThreadTermination(DefaultSolverScope solverScope, ChildThreadType childThreadType) Create a Termination for a child Thread of the Solver.
boolean	isPhaseTerminated(AbstractPhaseScope phaseScope) Called by the Phase after every step and every move to determine if the search should stop.
boolean	isSolverTerminated(DefaultSolverScope solverScope) Called by the Solver after every phase to determine if the search should stop.

Methods inherited from interface org.optaplanner.core.impl.phase.event.PhaseLifecycleListener

phaseEnded, phaseStarted, stepEnded, stepStarted

Methods inherited from interface org.optaplanner.core.impl.solver.event.SolverLifecycleListener

solvingEnded, solvingStarted

Method Detail

isSolverTerminated

boolean isSolverTerminated(DefaultSolverScope solverScope)

Called by the Solver after every phase to determine if the search should stop.

Parameters:

solverScope - never null

Returns:

true if the search should terminate.

isPhaseTerminated

boolean isPhaseTerminated(AbstractPhaseScope phaseScope)

Called by the Phase after every step and every move to determine if the search should stop.

Parameters:

phaseScope - never null

Returns:

true if the search should terminate.

calculateSolverTimeGradient

double calculateSolverTimeGradient(DefaultSolverScope solverScope)

A timeGradient is a relative estimate of how long the search will continue.

Clients that use a timeGradient should cache it at the start of a single step because some implementations are not time-stable.

If a timeGradient can not be calculated, it should return -1.0. Several implementations (such a SimulatedAnnealingAcceptor) require a correctly implemented timeGradient.

A Termination's timeGradient can be requested after they are terminated, so implementations should be careful not to return a timeGradient above 1.0.

Parameters:

solverScope - never null

Returns:

timeGradient t for which 0.0 <= t <= 1.0 or -1.0 when it is not supported. At the start of a solver t is 0.0 and at the end t would be 1.0.

calculatePhaseTimeGradient

double calculatePhaseTimeGradient(AbstractPhaseScope phaseScope)

See calculateSolverTimeGradient(DefaultSolverScope).

Parameters:

phaseScope - never null

Returns:

timeGradient t for which 0.0 <= t <= 1.0 or -1.0 when it is not supported. At the start of a phase t is 0.0 and at the end t would be 1.0.

createChildThreadTermination

Termination createChildThreadTermination(DefaultSolverScope solverScope,
                                         ChildThreadType childThreadType)

Create a Termination for a child Thread of the Solver.

Parameters:

solverScope - never null

childThreadType - never null

Returns:

not null

Throws:

UnsupportedOperationException - if not supported by this termination