Package ai.timefold.solver.core.impl.solver.termination

Class BasicPlumbingTermination<Solution_>

java.lang.Object

ai.timefold.solver.core.impl.solver.termination.BasicPlumbingTermination<Solution_>

All Implemented Interfaces:

PhaseLifecycleListener<Solution_>, SolverLifecycleListener<Solution_>, ChildThreadSupportingTermination<Solution_,SolverScope<Solution_>>, PhaseTermination<Solution_>, SolverTermination<Solution_>, Termination<Solution_>, UniversalTermination<Solution_>, EventListener

@NullMarked
public final class BasicPlumbingTermination<Solution_>
extends Object
implements ChildThreadSupportingTermination<Solution_,SolverScope<Solution_>>

Concurrency notes: Condition predicate on (problemChangeQueue is not empty or terminatedEarly is true).

Field Summary

Fields

Modifier and Type	Field	Description
protected final org.slf4j.Logger	logger

Constructor Summary

Constructors

Constructor	Description
BasicPlumbingTermination(boolean daemon)

Method Summary

Modifier and Type	Method	Description
boolean	addProblemChanges(List<ProblemChangeAdapter<Solution_>> problemChangeList)	Concurrency note: unblocks waitForRestartSolverDecision().
double	calculatePhaseTimeGradient(AbstractPhaseScope<Solution_> phaseScope)	A timeGradient is a relative estimate of how long the search will continue.
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.
void	endProblemChangesProcessing()
boolean	isEveryProblemChangeProcessed()
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.
boolean	isTerminateEarly()	This method is thread-safe.
void	phaseEnded(AbstractPhaseScope<Solution_> phaseScope)
void	phaseStarted(AbstractPhaseScope<Solution_> phaseScope)
void	resetTerminateEarly()	This method is thread-safe.
void	solvingEnded(SolverScope<Solution_> solverScope)
void	solvingStarted(SolverScope<Solution_> solverScope)
BlockingQueue<ProblemChangeAdapter<Solution_>>	startProblemChangesProcessing()
void	stepEnded(AbstractStepScope<Solution_> stepScope)
void	stepStarted(AbstractStepScope<Solution_> stepScope)
boolean	terminateEarly()	This method is thread-safe.
String	toString()
boolean	waitForRestartSolverDecision()	If this returns true, then the problemFactChangeQueue is definitely not empty.

Methods inherited from class java.lang.Object

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

Methods inherited from interface ai.timefold.solver.core.impl.solver.termination.PhaseTermination

isApplicableTo

Methods inherited from interface ai.timefold.solver.core.impl.solver.event.SolverLifecycleListener

solvingError

Methods inherited from interface ai.timefold.solver.core.impl.solver.termination.UniversalTermination

getPhaseTerminationList, getPhaseTerminationsInapplicableTo

Field Details

logger

protected final transient org.slf4j.Logger logger

Constructor Details

BasicPlumbingTermination

public BasicPlumbingTermination(boolean daemon)

Method Details

resetTerminateEarly

public void resetTerminateEarly()

This method is thread-safe.

terminateEarly

public boolean terminateEarly()

This method is thread-safe.

Concurrency note: unblocks waitForRestartSolverDecision().

Returns:

true if successful

isTerminateEarly

public boolean isTerminateEarly()

This method is thread-safe.

waitForRestartSolverDecision

public boolean waitForRestartSolverDecision()

If this returns true, then the problemFactChangeQueue is definitely not empty.

Concurrency note: Blocks until problemChangeQueue is not empty or terminatedEarly is true.

Returns:

true if the solver needs to be restarted

addProblemChanges

public boolean addProblemChanges(List<ProblemChangeAdapter<Solution_>> problemChangeList)

Concurrency note: unblocks waitForRestartSolverDecision().

Parameters:

problemChangeList - never null

Returns:

as specified by Collection.add(E)

startProblemChangesProcessing

public BlockingQueue<ProblemChangeAdapter<Solution_>> startProblemChangesProcessing()

endProblemChangesProcessing

public void endProblemChangesProcessing()

isEveryProblemChangeProcessed

public boolean isEveryProblemChangeProcessed()

isSolverTerminated

public boolean isSolverTerminated(SolverScope<Solution_> solverScope)

Description copied from interface: SolverTermination

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

Specified by:

isSolverTerminated in interface SolverTermination<Solution_>

Returns:

true if the search should terminate.

calculateSolverTimeGradient

public double calculateSolverTimeGradient(SolverScope<Solution_> solverScope)

Description copied from interface: SolverTermination

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.

Specified by:

calculateSolverTimeGradient in interface SolverTermination<Solution_>

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.

isPhaseTerminated

public boolean isPhaseTerminated(AbstractPhaseScope<Solution_> phaseScope)

Description copied from interface: PhaseTermination

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

Specified by:

isPhaseTerminated in interface PhaseTermination<Solution_>

Returns:

true if the search should terminate.

calculatePhaseTimeGradient

public double calculatePhaseTimeGradient(AbstractPhaseScope<Solution_> phaseScope)

Description copied from interface: PhaseTermination

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.

Specified by:

calculatePhaseTimeGradient in interface PhaseTermination<Solution_>

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.

createChildThreadTermination

public Termination<Solution_> createChildThreadTermination(SolverScope<Solution_> solverScope,
 ChildThreadType childThreadType)

Description copied from interface: ChildThreadSupportingTermination

Create a Termination for a child Thread of the Solver.

Specified by:

createChildThreadTermination in interface ChildThreadSupportingTermination<Solution_,SolverScope<Solution_>>

Parameters:

solverScope - Either SolverScope or AbstractPhaseScope

Returns:

not null

toString

public String toString()

Overrides:

toString in class Object

solvingStarted

public void solvingStarted(SolverScope<Solution_> solverScope)

Specified by:

solvingStarted in interface SolverLifecycleListener<Solution_>

solvingEnded

public void solvingEnded(SolverScope<Solution_> solverScope)

Specified by:

solvingEnded in interface SolverLifecycleListener<Solution_>

phaseStarted

public void phaseStarted(AbstractPhaseScope<Solution_> phaseScope)

Specified by:

phaseStarted in interface PhaseLifecycleListener<Solution_>

Specified by:

phaseStarted in interface PhaseTermination<Solution_>

stepStarted

public void stepStarted(AbstractStepScope<Solution_> stepScope)

Specified by:

stepStarted in interface PhaseLifecycleListener<Solution_>

Specified by:

stepStarted in interface PhaseTermination<Solution_>

stepEnded

public void stepEnded(AbstractStepScope<Solution_> stepScope)

Specified by:

stepEnded in interface PhaseLifecycleListener<Solution_>

Specified by:

stepEnded in interface PhaseTermination<Solution_>

phaseEnded

public void phaseEnded(AbstractPhaseScope<Solution_> phaseScope)

Specified by:

phaseEnded in interface PhaseLifecycleListener<Solution_>

Specified by:

phaseEnded in interface PhaseTermination<Solution_>