ParallelConstruction (Constraint Solver API Documentation -- CPSolver v1.4 build 75)

java.lang.Object
- org.cpsolver.ifs.assignment.context.NeighbourSelectionWithContext<V,T,ParallelConstruction.ConstructionContext>
- - org.cpsolver.ifs.algorithms.ParallelConstruction<V,T>

Type Parameters:

V - Variable

T - Value

All Implemented Interfaces:

CanHoldContext, HasAssignmentContext<V,T,ParallelConstruction.ConstructionContext>, NeighbourSelection<V,T>, SolutionListener<V,T>
```
public class ParallelConstruction<V extends Variable<V,T>,T extends Value<V,T>>
extends NeighbourSelectionWithContext<V,T,ParallelConstruction.ConstructionContext>
implements SolutionListener<V,T>
```
A simple neighbourhood selection extension suitable for the ParallelSolver during the construction phase. If the best ever found solution was found by a different thread (Assignment.getIndex() does not match) and the current solution has a smaller number of variables assigned for at least the given number of iterations (parameter ParallelConstruction.MaxIdle, defaults to 100), start assigning unassigned variables to their best values. Otherwise, pass the selection to the provided neighbourhood selection.

Version:

IFS 1.3 (Iterative Forward Search)
Copyright (C) 2014 Tomáš Müller
muller@unitime.org
http://muller.unitime.org

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not see http://www.gnu.org/licenses/.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

class ParallelConstruction.ConstructionContext

Nested Classes
Modifier and Type	Class and Description
`class`	`ParallelConstruction.ConstructionContext`

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`iBestAssigned`
`protected int`	`iBestIndex`
`protected Double`	`iBestValue`
`protected int`	`iMaxIdle`
`protected NeighbourSelection<V,T>`	`iParent`
`protected static org.apache.logging.log4j.Logger`	`sLog`

Fields inherited from class org.cpsolver.ifs.assignment.context.NeighbourSelectionWithContext
iContextOverride

Fields inherited from interface org.cpsolver.ifs.assignment.context.CanHoldContext
sMaxSize

Constructor Summary

Constructors
Constructor and Description

ParallelConstruction(DataProperties config, NeighbourSelection<V,T> parent)

Constructors
Constructor and Description
`ParallelConstruction(DataProperties config, NeighbourSelection<V,T> parent)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`bestCleared(Solution<V,T> solution)` Called by the solution when method `Solution.clearBest()` is called.
`void`	`bestRestored(Solution<V,T> solution)` Called by the solution when method `Solution.restoreBest()` is called.
`void`	`bestSaved(Solution<V,T> solution)` Called by the solution when method `Solution.saveBest()` is called.
`ParallelConstruction.ConstructionContext`	`createAssignmentContext(Assignment<V,T> assignment)` Create a new assignment context for the given assignment.
`void`	`getInfo(Solution<V,T> solution, Map<String,String> info)` Called by the solution when it is asked to produce info table, see `Solution.getInfo()`.
`void`	`getInfo(Solution<V,T> solution, Map<String,String> info, Collection<V> variables)` Called by the solution when it is asked to produce info table, see `Solution.getInfo()`.
`void`	`init(Solver<V,T> solver)` Criterion initialization
`Neighbour<V,T>`	`selectNeighbour(Solution<V,T> solution)` select a neighbour of a given solution
`void`	`solutionUpdated(Solution<V,T> solution)` Called by the solution when it is updated, see `Solution.update(double)`.

Methods inherited from class org.cpsolver.ifs.assignment.context.NeighbourSelectionWithContext
getAssignmentContextReference, getContext, getContext, hasContextOverride, isSingleContextSolver, setAssignmentContextReference

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - sLog
```
protected static org.apache.logging.log4j.Logger sLog
```
  - iParent
```
protected NeighbourSelection<V extends Variable<V,T>,T extends Value<V,T>> iParent
```
  - iBestValue
```
protected Double iBestValue
```
  - iBestIndex
```
protected int iBestIndex
```
  - iBestAssigned
```
protected int iBestAssigned
```
  - iMaxIdle
```
protected int iMaxIdle
```
- Constructor Detail
  - ParallelConstruction
```
public ParallelConstruction(DataProperties config,
                            NeighbourSelection<V,T> parent)
```
- Method Detail
  - init
```
public void init(Solver<V,T> solver)
```
    Description copied from interface: NeighbourSelection
    
    Criterion initialization
    
    Specified by:
    
    init in interface NeighbourSelection<V extends Variable<V,T>,T extends Value<V,T>>
    
    Overrides:
    
    init in class NeighbourSelectionWithContext<V extends Variable<V,T>,T extends Value<V,T>,ParallelConstruction.ConstructionContext>
    
    Parameters:
    
    solver - current solver
  - solutionUpdated
```
public void solutionUpdated(Solution<V,T> solution)
```
    Description copied from interface: SolutionListener
    
    Called by the solution when it is updated, see Solution.update(double).
    
    Specified by:
    
    solutionUpdated in interface SolutionListener<V extends Variable<V,T>,T extends Value<V,T>>
    
    Parameters:
    
    solution - source solution
  - getInfo
```
public void getInfo(Solution<V,T> solution,
                    Map<String,String> info)
```
    Description copied from interface: SolutionListener
    
    Called by the solution when it is asked to produce info table, see Solution.getInfo(). A listener can also add some its info into this table.
    
    Specified by:
    
    getInfo in interface SolutionListener<V extends Variable<V,T>,T extends Value<V,T>>
    
    Parameters:
    
    solution - source solution
    
    info - produced info table
  - getInfo
```
public void getInfo(Solution<V,T> solution,
                    Map<String,String> info,
                    Collection<V> variables)
```
    Description copied from interface: SolutionListener
    
    Called by the solution when it is asked to produce info table, see Solution.getInfo(). A listener can also add some its info into this table.
    
    Specified by:
    
    getInfo in interface SolutionListener<V extends Variable<V,T>,T extends Value<V,T>>
    
    Parameters:
    
    solution - source solution
    
    info - produced info table
    
    variables - only variables from this set are included
  - bestCleared
```
public void bestCleared(Solution<V,T> solution)
```
    Description copied from interface: SolutionListener
    
    Called by the solution when method Solution.clearBest() is called.
    
    Specified by:
    
    bestCleared in interface SolutionListener<V extends Variable<V,T>,T extends Value<V,T>>
    
    Parameters:
    
    solution - source solution
  - bestSaved
```
public void bestSaved(Solution<V,T> solution)
```
    Description copied from interface: SolutionListener
    
    Called by the solution when method Solution.saveBest() is called.
    
    Specified by:
    
    bestSaved in interface SolutionListener<V extends Variable<V,T>,T extends Value<V,T>>
    
    Parameters:
    
    solution - source solution
  - bestRestored
```
public void bestRestored(Solution<V,T> solution)
```
    Description copied from interface: SolutionListener
    
    Called by the solution when method Solution.restoreBest() is called.
    
    Specified by:
    
    bestRestored in interface SolutionListener<V extends Variable<V,T>,T extends Value<V,T>>
    
    Parameters:
    
    solution - source solution
  - selectNeighbour
```
public Neighbour<V,T> selectNeighbour(Solution<V,T> solution)
```
    Description copied from interface: NeighbourSelection
    
    select a neighbour of a given solution
    
    Specified by:
    
    selectNeighbour in interface NeighbourSelection<V extends Variable<V,T>,T extends Value<V,T>>
    
    Parameters:
    
    solution - given solution
    
    Returns:
    
    a neighbour assignment
  - createAssignmentContext
```
public ParallelConstruction.ConstructionContext createAssignmentContext(Assignment<V,T> assignment)
```
    Description copied from interface: HasAssignmentContext
    
    Create a new assignment context for the given assignment. If there are already some variables assigned in the value, the method should make sure that the context is appropriately initialized.
    
    Specified by:
    
    createAssignmentContext in interface HasAssignmentContext<V extends Variable<V,T>,T extends Value<V,T>,ParallelConstruction.ConstructionContext>
    
    Parameters:
    
    assignment - an assignment for which there needs to be an assignment context
    
    Returns:
    
    a new instance of the assignment context, filled according to the given assignment

Class ParallelConstruction<V extends Variable<V,T>,T extends Value<V,T>>

Nested Class Summary

Field Summary

Fields inherited from class org.cpsolver.ifs.assignment.context.NeighbourSelectionWithContext

Fields inherited from interface org.cpsolver.ifs.assignment.context.CanHoldContext

Constructor Summary

Method Summary

Methods inherited from class org.cpsolver.ifs.assignment.context.NeighbourSelectionWithContext

Methods inherited from class java.lang.Object

Field Detail

sLog

iParent

iBestValue

iBestIndex

iBestAssigned

iMaxIdle

Constructor Detail

ParallelConstruction

Method Detail

init

solutionUpdated

getInfo

getInfo

bestCleared

bestSaved

bestRestored

selectNeighbour

createAssignmentContext