| /* |
| * 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; |
| |
| import org.mmtk.plan.TraceLocal; |
| import org.mmtk.plan.Trace; |
| import org.mmtk.utility.HeaderByte; |
| import org.mmtk.utility.deque.*; |
| |
| import org.mmtk.vm.VM; |
| |
| import org.vmmagic.unboxed.*; |
| import org.vmmagic.pragma.*; |
| |
| /** |
| * This abstract class implments the core functionality for a transitive |
| * closure over the heap graph. |
| */ |
| @Uninterruptible |
| public abstract class GenMatureTraceLocal extends TraceLocal { |
| |
| /**************************************************************************** |
| * |
| * Instance fields. |
| */ |
| private final ObjectReferenceDeque modbuf; |
| private final AddressDeque remset; |
| private final AddressPairDeque arrayRemset; |
| |
| /**************************************************************************** |
| * |
| * Initialization |
| */ |
| |
| /** |
| * Constructor |
| */ |
| public GenMatureTraceLocal(int specializedScan, Trace trace, GenCollector plan) { |
| super(specializedScan, trace); |
| this.modbuf = plan.modbuf; |
| this.remset = plan.remset; |
| this.arrayRemset = plan.arrayRemset; |
| } |
| |
| /** |
| * Constructor |
| */ |
| public GenMatureTraceLocal(Trace trace, GenCollector plan) { |
| super(Gen.SCAN_MATURE, trace); |
| this.modbuf = plan.modbuf; |
| this.remset = plan.remset; |
| this.arrayRemset = plan.arrayRemset; |
| } |
| |
| /**************************************************************************** |
| * |
| * Object processing and tracing |
| */ |
| |
| /** |
| * Is the specified object live? |
| * |
| * @param object The object. |
| * @return True if the object is live. |
| */ |
| @Inline |
| public boolean isLive(ObjectReference object) { |
| if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(!object.isNull()); |
| if (Gen.inNursery(object)) { |
| return Gen.nurserySpace.isLive(object); |
| } |
| return super.isLive(object); |
| } |
| |
| /** |
| * 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 (Gen.inNursery(object)) |
| return false; |
| else |
| return super.willNotMoveInCurrentCollection(object); |
| } |
| |
| /** |
| * This method is the core method during the trace of the object graph. |
| * The role of this method is to: |
| * |
| * 1. Ensure the traced object is not collected. |
| * 2. If this is the first visit to the object enqueue it to be scanned. |
| * 3. Return the forwarded reference to the object. |
| * |
| * @param object The object to be traced. |
| * @return The new reference to the same object instance. |
| */ |
| @Inline |
| public ObjectReference traceObject(ObjectReference object) { |
| if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(!object.isNull()); |
| if (Gen.inNursery(object)) |
| return Gen.nurserySpace.traceObject(this, object, Gen.ALLOC_MATURE_MAJORGC); |
| return super.traceObject(object); |
| } |
| |
| /** |
| * Process any remembered set entries. |
| */ |
| protected void processRememberedSets() { |
| logMessage(5, "clearing modbuf"); |
| ObjectReference obj; |
| while (!(obj = modbuf.pop()).isNull()) { |
| HeaderByte.markAsUnlogged(obj); |
| } |
| logMessage(5, "clearing remset"); |
| while (!remset.isEmpty()) { |
| remset.pop(); |
| } |
| logMessage(5, "clearing array remset"); |
| while (!arrayRemset.isEmpty()) { |
| arrayRemset.pop1(); |
| arrayRemset.pop2(); |
| } |
| } |
| |
| } |