Mercurial > hg > truffle
view agent/src/share/classes/sun/jvm/hotspot/memory/FreeChunk.java @ 12837:82af7d7a0128
8003420: NPG: make new GC root for pd_set
Summary: Move protection domain oops from system dictionary entries into a seperate set; the system dictionary references entries in that set now. This allows fast iteration during non-classunloading garbage collection. Implementation based on initial prototype from Ioi Lam (iklam).
Reviewed-by: coleenp, iklam
author | tschatzl |
---|---|
date | Wed, 09 Oct 2013 10:57:01 +0200 |
parents | c18cbe5936b8 |
children |
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/* * Copyright (c) 2003, 2009, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ package sun.jvm.hotspot.memory; import java.util.*; import sun.jvm.hotspot.debugger.*; import sun.jvm.hotspot.types.*; import sun.jvm.hotspot.runtime.*; import sun.jvm.hotspot.oops.*; public class FreeChunk extends VMObject { static { VM.registerVMInitializedObserver(new Observer() { public void update(Observable o, Object data) { initialize(VM.getVM().getTypeDataBase()); } }); } private static synchronized void initialize(TypeDataBase db) { Type type = db.lookupType("FreeChunk"); nextField = type.getAddressField("_next"); prevField = type.getAddressField("_prev"); sizeField = type.getAddressField("_size"); } // Fields private static AddressField nextField; private static AddressField prevField; private static AddressField sizeField; // Accessors public FreeChunk next() { return (FreeChunk) VMObjectFactory.newObject(FreeChunk.class, nextField.getValue(addr)); } public FreeChunk prev() { Address prev = prevField.getValue(addr).andWithMask(~0x3); return (FreeChunk) VMObjectFactory.newObject(FreeChunk.class, prev); } public long size() { if (VM.getVM().isCompressedOopsEnabled()) { Mark mark = new Mark(addr.addOffsetTo(sizeField.getOffset())); return mark.getSize(); } else { Address size = sizeField.getValue(addr); Debugger dbg = VM.getVM().getDebugger(); return dbg.getAddressValue(size); } } public FreeChunk(Address addr) { super(addr); } public static boolean indicatesFreeChunk(Address cur) { FreeChunk f = new FreeChunk(cur); return f.isFree(); } public boolean isFree() { if (VM.getVM().isCompressedOopsEnabled()) { Mark mark = new Mark(addr.addOffsetTo(sizeField.getOffset())); return mark.isCmsFreeChunk(); } else { Address prev = prevField.getValue(addr); Debugger dbg = VM.getVM().getDebugger(); long word = dbg.getAddressValue(prev); return (word & 0x1L) == 0x1L; } } }