Package org.jacop.jasat.modules

Class HeuristicRestartModule

java.lang.Object
org.jacop.jasat.modules.HeuristicRestartModule
All Implemented Interfaces:
SolverComponent, BackjumpListener, ConflictListener
public final class HeuristicRestartModule extends Object implements ConflictListener, BackjumpListener
A module that indicates if a restart would be useful now. Currently based on number of conflicts since last restart. Each restart makes the next restart twice harder to reach.
Version:
4.10

  • Field Details

    • shouldRestart

      public boolean shouldRestart

    • conflictCount

      private long conflictCount

    • threshold

      private long threshold

    • THRESHOLD_INCREASE_RATE

      private double THRESHOLD_INCREASE_RATE

  • Constructor Details

    • HeuristicRestartModule

      public HeuristicRestartModule()

  • Method Details

    • onConflict

      public void onConflict(MapClause clause, int level)
      Description copied from interface: ConflictListener
      called when a conflict occurs
      Specified by:
      onConflict in interface ConflictListener
      Parameters:
      clause - the conflict (unsatisfiable) clause
      level - the level at which the conflict occurred

    • onBackjump

      public void onBackjump(int oldLevel, int newLevel)
      Description copied from interface: BackjumpListener
      Called when the solver backtracks. It will also be called when the solver restarts.

      components that want to be warned about backjumps should put themselves in Core.backjumpModules.

      Specified by:
      onBackjump in interface BackjumpListener
      Parameters:
      oldLevel - the level at which the solver was before backtracking
      newLevel - the level to which the solver backtracks

    • onRestart

      public void onRestart(int oldLevel)
      Description copied from interface: BackjumpListener
      called when the solver restarts.

      components that want to be warned about restarts should put themselves in Core.restartModules.

      Specified by:
      onRestart in interface BackjumpListener
      Parameters:
      oldLevel - the level at which the solver was before restarting

    • initialize

      public void initialize(Core core)
      Description copied from interface: SolverComponent
      initializes the component with the given solver. May be called only once. This method must register the component to the solver for the run.
      Specified by:
      initialize in interface SolverComponent
      Parameters:
      core - core component to initialize