Package org.optaplanner.core.impl.solver.termination

Interface Termination<Solution_>

All Superinterfaces:

EventListener, PhaseLifecycleListener<Solution_>, SolverLifecycleListener<Solution_>

All Known Implementing Classes:

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

public interface Termination<Solution_>
extends PhaseLifecycleListener<Solution_>

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

Method Detail

isSolverTerminated

boolean isSolverTerminated(SolverScope<Solution_> 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<Solution_> 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(SolverScope<Solution_> 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 cannot 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<Solution_> phaseScope)

See calculateSolverTimeGradient(SolverScope).

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<Solution_> createChildThreadTermination(SolverScope<Solution_> 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