| /* |
| * 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.generational.copying; |
| |
| import org.mmtk.plan.generational.Gen; |
| import org.mmtk.plan.generational.GenCollector; |
| import org.mmtk.plan.generational.GenMatureTraceLocal; |
| import org.mmtk.plan.Trace; |
| import org.mmtk.policy.Space; |
| |
| import org.mmtk.vm.VM; |
| |
| import org.vmmagic.pragma.*; |
| import org.vmmagic.unboxed.*; |
| |
| /** |
| * This class implments the core functionality for a transitive |
| * closure over the heap graph, specifically in a Generational copying |
| * collector. |
| */ |
| @Uninterruptible |
| public final class GenCopyMatureTraceLocal extends GenMatureTraceLocal { |
| |
| /** |
| * Constructor |
| */ |
| public GenCopyMatureTraceLocal(Trace global, GenCollector plan) { |
| super(global, plan); |
| } |
| |
| private static GenCopy global() { |
| return (GenCopy) VM.activePlan.global(); |
| } |
| |
| /** |
| * Trace a reference into the mature space during GC. This involves |
| * determining whether the instance is in from space, and if so, |
| * calling the <code>traceObject</code> method of the Copy |
| * collector. |
| * |
| * @param object The object reference to be traced. This is <i>NOT</i> an |
| * interior pointer. |
| * @return The possibly moved reference. |
| */ |
| public ObjectReference traceObject(ObjectReference object) { |
| if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(global().traceFullHeap()); |
| if (object.isNull()) return object; |
| |
| if (Space.isInSpace(GenCopy.MS0, object)) |
| return GenCopy.matureSpace0.traceObject(this, object, Gen.ALLOC_MATURE_MAJORGC); |
| if (Space.isInSpace(GenCopy.MS1, object)) |
| return GenCopy.matureSpace1.traceObject(this, object, Gen.ALLOC_MATURE_MAJORGC); |
| return super.traceObject(object); |
| } |
| |
| /** |
| * Return true if <code>obj</code> is a live object. |
| * |
| * @param object The object in question |
| * @return True if <code>obj</code> is a live object. |
| */ |
| public boolean isLive(ObjectReference object) { |
| if (object.isNull()) return false; |
| if (Space.isInSpace(GenCopy.MS0, object)) |
| return GenCopy.hi ? GenCopy.matureSpace0.isLive(object) : true; |
| if (Space.isInSpace(GenCopy.MS1, object)) |
| return GenCopy.hi ? true : GenCopy.matureSpace1.isLive(object); |
| return super.isLive(object); |
| } |
| |
| /**************************************************************************** |
| * |
| * Object processing and tracing |
| */ |
| |
| |
| /** |
| * Return true if this object is guaranteed not to move during this |
| * collection (i.e. this object is defintely not an unforwarded |
| * object). |
| * |
| * @param object |
| * @return True if this object is guaranteed not to move during this |
| * collection. |
| */ |
| public boolean willNotMoveInCurrentCollection(ObjectReference object) { |
| if (Space.isInSpace(GenCopy.toSpaceDesc(), object)) { |
| return true; |
| } |
| if (Space.isInSpace(GenCopy.fromSpaceDesc(), object)) { |
| return false; |
| } |
| return super.willNotMoveInCurrentCollection(object); |
| } |
| } |