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.mmtk.plan.nogc;
014    
015    import org.mmtk.plan.*;
016    import org.mmtk.vm.VM;
017    
018    import org.vmmagic.pragma.*;
019    
020    /**
021     * This class implements <i>per-collector thread</i> behavior and state
022     * for the <i>NoGC</i> plan, which simply allocates (without ever collecting
023     * until the available space is exhausted.<p>
024     *
025     * Specifically, this class <i>would</i> define <i>NoGC</i> collection time semantics,
026     * however, since this plan never collects, this class consists only of stubs which
027     * may be useful as a template for implementing a basic collector.
028     *
029     * @see NoGC
030     * @see NoGCMutator
031     * @see CollectorContext
032     */
033    @Uninterruptible
034    public class NoGCCollector extends CollectorContext {
035    
036      /************************************************************************
037       * Instance fields
038       */
039      private final NoGCTraceLocal trace = new NoGCTraceLocal(global().trace);
040      protected final TraceLocal currentTrace = trace;
041    
042    
043      /****************************************************************************
044       * Collection
045       */
046    
047      /**
048       * Perform a garbage collection
049       */
050      @Override
051      public final void collect() {
052        VM.assertions.fail("GC Triggered in NoGC Plan. Is -X:gc:ignoreSystemGC=true ?");
053      }
054    
055      /** Perform some concurrent garbage collection */
056      @Override
057      public final void concurrentCollect() {
058        VM.assertions.fail("Concurrent GC Triggered in NoGC Plan.");
059      }
060    
061      /**
062       * Perform a per-collector collection phase.
063       *
064       * @param phaseId The collection phase to perform
065       * @param primary perform any single-threaded local activities.
066       */
067      @Inline
068      @Override
069      public final void collectionPhase(short phaseId, boolean primary) {
070        VM.assertions.fail("GC Triggered in NoGC Plan.");
071        /*
072        if (phaseId == NoGC.PREPARE) {
073        }
074    
075        if (phaseId == NoGC.CLOSURE) {
076        }
077    
078        if (phaseId == NoGC.RELEASE) {
079        }
080    
081        super.collectionPhase(phaseId, primary);
082        */
083      }
084    
085      /**
086       * Perform some concurrent collection work.
087       *
088       * @param phaseId The unique phase identifier
089       */
090      @Override
091      public void concurrentCollectionPhase(short phaseId) {
092        VM.assertions.fail("GC Triggered in NoGC Plan.");
093      }
094    
095    
096      /****************************************************************************
097       * Miscellaneous
098       */
099    
100      /** @return The active global plan as a <code>NoGC</code> instance. */
101      @Inline
102      private static NoGC global() {
103        return (NoGC) VM.activePlan.global();
104      }
105    
106      /** @return The current trace instance. */
107      @Override
108      public final TraceLocal getCurrentTrace() {
109        return currentTrace;
110      }
111    }