org.eclipse.viatra.dse.api.strategy.impl

Class DepthFirstStrategy

java.lang.Object

org.eclipse.viatra.dse.api.strategy.impl.DepthFirstStrategy

All Implemented Interfaces:

IStrategy

public class DepthFirstStrategy
extends java.lang.Object
implements IStrategy

A depth-first search algorithm implementation, that

• can work with multiple threads,
• randomly traverses the search space,
• saves all states (trajectories) as solutions that fulfill all the hard objectives,
• can have a depth limit,
• will backtrack when a model satisfies the hard objectives (after saving it as a solution), which can be modified by calling continueIfHardObjectivesFulfilled()

Constructor Summary

Constructors

Constructor and Description
DepthFirstStrategy() Creates a new depth-first search algorithm without depth limit.
DepthFirstStrategy(int maxDepth) Creates a new depth-first search algorithm with depth limit.

Method Summary

Modifier and Type	Method and Description
DepthFirstStrategy	continueIfHardObjectivesFulfilled() If called, the algorithm will not backtrack after the hard objectives are fulfilled, instead it goes deeper in the search space.
void	explore() This method explores the design space as the implementation specifies.
void	initStrategy(ThreadContext context) Initializes the strategy with a specific ThreadContext.
void	interruptStrategy() The implementation of this interface should be ready to be interrupted.

Methods inherited from class java.lang.Object

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

Constructor Detail

DepthFirstStrategy

public DepthFirstStrategy()

Creates a new depth-first search algorithm without depth limit.

DepthFirstStrategy

public DepthFirstStrategy(int maxDepth)

Creates a new depth-first search algorithm with depth limit.

Parameters:

maxDepth - A negative maxDepth means no depth limit, zero means the checking of the initial state.

Method Detail

continueIfHardObjectivesFulfilled

public DepthFirstStrategy continueIfHardObjectivesFulfilled()

If called, the algorithm will not backtrack after the hard objectives are fulfilled, instead it goes deeper in the search space.

initStrategy

public void initStrategy(ThreadContext context)

Description copied from interface: IStrategy

Initializes the strategy with a specific ThreadContext.

Specified by:

initStrategy in interface IStrategy

Parameters:

context - The context.

explore

public void explore()

Description copied from interface: IStrategy

This method explores the design space as the implementation specifies. It will be called only once, hence the exploration loop is run by the implementation. The termination condition is also specified by the implementation and when it returns the exploration thread will be disposed.

Specified by:

explore in interface IStrategy

interruptStrategy

public void interruptStrategy()

Description copied from interface: IStrategy

The implementation of this interface should be ready to be interrupted. If this method is called, the IStrategy.explore() method should return ASAP. This method is also called by the SolutionStore class if enough solutions are found.

Specified by:

interruptStrategy in interface IStrategy