| /* |
| * This file is part of the Jikes RVM project (http://jikesrvm.org). |
| * |
| * This file is licensed to You under the Eclipse Public License (EPL); |
| * You may not use this file except in compliance with the License. You |
| * may obtain a copy of the License at |
| * |
| * http://www.opensource.org/licenses/eclipse-1.0.php |
| * |
| * See the COPYRIGHT.txt file distributed with this work for information |
| * regarding copyright ownership. |
| */ |
| package org.mmtk.plan.semispace.gctrace; |
| |
| import org.mmtk.plan.*; |
| import org.mmtk.plan.semispace.*; |
| import org.mmtk.vm.VM; |
| |
| import org.vmmagic.pragma.*; |
| |
| |
| /** |
| * This class implements <i>per-collector thread</i> behavior and state for the |
| * <i>GCTrace</i> plan, which implements a GC tracing algorithm.<p> |
| * |
| * Specifically, this class defines <i>SS</i> collection behavior |
| * (through <code>inducedTrace</code> and the <code>collectionPhase</code> |
| * method), and collection-time allocation (copying of objects).<p> |
| * |
| * See {@link GCTrace} for an overview of the GC trace algorithm.<p> |
| * |
| * @see SSCollector |
| * @see GCTrace |
| * @see GCTraceMutator |
| * @see org.mmtk.plan.StopTheWorldCollector |
| * @see org.mmtk.plan.CollectorContext |
| */ |
| @Uninterruptible public class GCTraceCollector extends SSCollector { |
| /**************************************************************************** |
| * Instance fields |
| */ |
| protected final GCTraceTraceLocal inducedTrace; |
| |
| /**************************************************************************** |
| * |
| * Initialization |
| */ |
| |
| /** |
| * Constructor |
| */ |
| public GCTraceCollector() { |
| inducedTrace = new GCTraceTraceLocal(global().ssTrace); |
| } |
| |
| /**************************************************************************** |
| * |
| * Collection |
| */ |
| |
| /** |
| * Perform a per-collector collection phase. |
| * |
| * @param phaseId The collection phase to perform |
| * @param primary perform any single-threaded local activities. |
| */ |
| public void collectionPhase(short phaseId, boolean primary) { |
| if (phaseId == GCTrace.CLOSURE) { |
| inducedTrace.completeTrace(); |
| return; |
| } |
| |
| if (phaseId == GCTrace.RELEASE) { |
| inducedTrace.release(); |
| if (!GCTrace.traceInducedGC) { |
| super.collectionPhase(phaseId, primary); |
| } |
| return; |
| } |
| |
| /* fall through case */ |
| if (!GCTrace.traceInducedGC || |
| ((phaseId != StopTheWorld.SOFT_REFS) && |
| (phaseId != StopTheWorld.WEAK_REFS) && |
| (phaseId != StopTheWorld.PHANTOM_REFS) && |
| (phaseId != StopTheWorld.FINALIZABLE) && |
| (phaseId != SS.PREPARE))) { |
| // Delegate up. |
| super.collectionPhase(phaseId, primary); |
| } |
| } |
| |
| /**************************************************************************** |
| * |
| * Miscellaneous |
| */ |
| |
| /** @return The active global plan as a <code>GCTrace</code> instance. */ |
| @Inline |
| private static GCTrace global() { |
| return (GCTrace) VM.activePlan.global(); |
| } |
| |
| /** @return The current trace instance */ |
| public TraceLocal getCurrentTrace() { |
| return inducedTrace; |
| } |
| } |