| /* |
| * 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.refcount.backuptrace; |
| |
| import org.mmtk.plan.TraceLocal; |
| import org.mmtk.plan.Trace; |
| import org.mmtk.plan.refcount.RCBase; |
| import org.mmtk.plan.refcount.RCHeader; |
| |
| import org.vmmagic.pragma.*; |
| import org.vmmagic.unboxed.*; |
| |
| /** |
| * This class implements the thread-local core functionality for a transitive |
| * closure over the heap graph. |
| */ |
| @Uninterruptible |
| public final class BTTraceLocal extends TraceLocal { |
| /** |
| * Constructor |
| */ |
| public BTTraceLocal(Trace trace) { |
| super(trace); |
| } |
| |
| /**************************************************************************** |
| * |
| * Externally visible Object processing and tracing |
| */ |
| |
| /** |
| * Is the specified object reachable? |
| * |
| * @param object The object. |
| * @return <code>true</code> if the object is reachable. |
| */ |
| public boolean isLive(ObjectReference object) { |
| return !RCBase.isRCObject(object) || RCHeader.isMarked(object); |
| } |
| |
| /** |
| * When we trace a non-root object we do nothing. |
| * |
| * @param object The object to be traced. |
| * @return The new reference to the same object instance. |
| */ |
| @Inline |
| public ObjectReference traceObject(ObjectReference object) { |
| if (RCBase.isRCObject(object)) { |
| if (RCHeader.testAndMark(object)) { |
| processNode(object); |
| } |
| } |
| return object; |
| } |
| } |