001    /*
002     *  This file is part of the Jikes RVM project (http://jikesrvm.org).
003     *
004     *  This file is licensed to You under the Eclipse Public License (EPL);
005     *  You may not use this file except in compliance with the License. You
006     *  may obtain a copy of the License at
007     *
008     *      http://www.opensource.org/licenses/eclipse-1.0.php
009     *
010     *  See the COPYRIGHT.txt file distributed with this work for information
011     *  regarding copyright ownership.
012     */
013    package org.jikesrvm.adaptive.recompilation;
014    
015    import org.jikesrvm.adaptive.OnStackReplacementPlan;
016    import org.jikesrvm.adaptive.controller.Controller;
017    import org.jikesrvm.adaptive.controller.ControllerPlan;
018    import org.jikesrvm.scheduler.RVMThread;
019    import org.vmmagic.pragma.NonMoving;
020    
021    /**
022     *  This class is a separate thread whose job is to monitor a (priority)
023     *  queue of compilation plans.  Whenever the queue is nonempty, this
024     *  thread will pick the highest priority compilation plan from the queue
025     *  and invoke the OPT compiler to perform the plan.
026     *
027     *  No intelligence is contained in this class.  All policy decisions are
028     *  made by the controllerThread.
029     */
030    @NonMoving
031    public final class CompilationThread extends RVMThread {
032    
033      /**
034       * constructor
035       */
036      public CompilationThread() {
037        super("CompilationThread");
038        makeDaemon(true);
039      }
040    
041      /**
042       * This is the main loop of the compilation thread. It's job is to
043       * remove controller plans from the compilation queue and perform
044       * them.
045       */
046      public void run() {
047        // Make a blocking call to deleteMin to get a plan and then execute it.
048        // Repeat...
049        while (true) {
050          Object plan = Controller.compilationQueue.deleteMin();
051          if (plan instanceof ControllerPlan) {
052            ((ControllerPlan) plan).doRecompile();
053          } else if (plan instanceof OnStackReplacementPlan) {
054            ((OnStackReplacementPlan) plan).execute();
055          }
056        }
057      }
058    
059    }
060