/* * 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.copyms; import org.mmtk.plan.*; import org.mmtk.policy.CopySpace; import org.mmtk.policy.MarkSweepSpace; import org.mmtk.policy.Space; import org.mmtk.utility.heap.VMRequest; import org.mmtk.utility.options.Options; import org.mmtk.utility.sanitychecker.SanityChecker; import org.vmmagic.pragma.*; import org.vmmagic.unboxed.ObjectReference; /** * This class implements the global state of a full-heap collector * with a copying nursery and mark-sweep mature space. Unlike a full * generational collector, there is no write barrier, no remembered set, and * every collection is full-heap.<p> * * All plans make a clear distinction between <i>global</i> and * <i>thread-local</i> activities, and divides global and local state * into separate class hierarchies. Global activities must be * synchronized, whereas no synchronization is required for * thread-local activities. There is a single instance of Plan (or the * appropriate sub-class), and a 1:1 mapping of PlanLocal to "kernel * threads" (aka CPUs). Thus instance * methods of PlanLocal allow fast, unsychronized access to functions such as * allocation and collection.<p> * * The global instance defines and manages static resources * (such as memory and virtual memory resources). This mapping of threads to * instances is crucial to understanding the correctness and * performance properties of MMTk plans. */ @Uninterruptible public class CopyMS extends StopTheWorld { /**************************************************************************** * Constants */ /**************************************************************************** * Class variables */ /** * */ public static final CopySpace nurserySpace = new CopySpace("nursery", false, VMRequest.highFraction(0.15f)); public static final MarkSweepSpace msSpace = new MarkSweepSpace("ms", VMRequest.discontiguous()); public static final int NURSERY = nurserySpace.getDescriptor(); public static final int MARK_SWEEP = msSpace.getDescriptor(); public static final int ALLOC_NURSERY = ALLOC_DEFAULT; public static final int ALLOC_MS = StopTheWorld.ALLOCATORS + 1; public static final int SCAN_COPYMS = 0; /**************************************************************************** * Instance variables */ /** * */ public final Trace trace; /** * Constructor. */ public CopyMS() { trace = new Trace(metaDataSpace); } /***************************************************************************** * Collection */ /** * {@inheritDoc} */ @Override @Inline public final void collectionPhase(short phaseId) { if (phaseId == PREPARE) { super.collectionPhase(phaseId); trace.prepare(); msSpace.prepare(true); nurserySpace.prepare(true); return; } if (phaseId == CLOSURE) { trace.prepare(); return; } if (phaseId == RELEASE) { trace.release(); msSpace.release(); nurserySpace.release(); switchNurseryZeroingApproach(nurserySpace); super.collectionPhase(phaseId); return; } super.collectionPhase(phaseId); } @Override public final boolean collectionRequired(boolean spaceFull, Space space) { boolean nurseryFull = nurserySpace.reservedPages() > Options.nurserySize.getMaxNursery(); return super.collectionRequired(spaceFull, space) || nurseryFull; } /***************************************************************************** * * Accounting */ /** * {@inheritDoc} */ @Override public int getPagesUsed() { return super.getPagesUsed() + msSpace.reservedPages() + nurserySpace.reservedPages(); } /** * Return the number of pages reserved for collection. * For mark sweep this is a fixed fraction of total pages. */ @Override public int getCollectionReserve() { return nurserySpace.reservedPages() + super.getCollectionReserve(); } /** * @return The number of pages available for allocation, <i>assuming * all future allocation is to the nursery</i>. */ @Override public final int getPagesAvail() { return (getTotalPages() - getPagesReserved()) >> 1; } @Override public int sanityExpectedRC(ObjectReference object, int sanityRootRC) { Space space = Space.getSpaceForObject(object); // Nursery if (space == CopyMS.nurserySpace) { return SanityChecker.DEAD; } return space.isReachable(object) ? SanityChecker.ALIVE : SanityChecker.DEAD; } @Override @Interruptible protected void registerSpecializedMethods() { TransitiveClosure.registerSpecializedScan(SCAN_COPYMS, CopyMSTraceLocal.class); super.registerSpecializedMethods(); } @Interruptible @Override public void fullyBooted() { super.fullyBooted(); nurserySpace.setZeroingApproach(Options.nurseryZeroing.getNonTemporal(), Options.nurseryZeroing.getConcurrent()); } }