Mercurial > hg > truffle
annotate agent/src/share/classes/sun/jvm/hotspot/utilities/RobustOopDeterminator.java @ 196:d1605aabd0a1 jdk7-b30
6719955: Update copyright year
Summary: Update copyright year for files that have been modified in 2008
Reviewed-by: ohair, tbell
| author | xdono |
|---|---|
| date | Wed, 02 Jul 2008 12:55:16 -0700 |
| parents | ba764ed4b6f2 |
| children | c18cbe5936b8 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 196 | 2 * Copyright 2000-2008 Sun Microsystems, Inc. All Rights Reserved. |
| 0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 * | |
| 5 * This code is free software; you can redistribute it and/or modify it | |
| 6 * under the terms of the GNU General Public License version 2 only, as | |
| 7 * published by the Free Software Foundation. | |
| 8 * | |
| 9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 12 * version 2 for more details (a copy is included in the LICENSE file that | |
| 13 * accompanied this code). | |
| 14 * | |
| 15 * You should have received a copy of the GNU General Public License version | |
| 16 * 2 along with this work; if not, write to the Free Software Foundation, | |
| 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 18 * | |
| 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
| 20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
| 21 * have any questions. | |
| 22 * | |
| 23 */ | |
| 24 | |
| 25 package sun.jvm.hotspot.utilities; | |
| 26 | |
| 27 import java.util.*; | |
| 28 import sun.jvm.hotspot.debugger.*; | |
| 29 import sun.jvm.hotspot.memory.*; | |
| 30 import sun.jvm.hotspot.runtime.*; | |
| 31 import sun.jvm.hotspot.types.*; | |
| 32 | |
| 33 /** This class determines to the best of its ability, and in a | |
| 34 reasonably robust fashion, whether a given pointer is an intact | |
| 35 oop or not. It does this by checking the integrity of the | |
| 36 metaclass hierarchy. This is only intended for use in the | |
| 37 debugging system. It may provide more resilience to unexpected VM | |
| 38 states than the ObjectHeap code. */ | |
| 39 | |
| 40 public class RobustOopDeterminator { | |
| 41 private static OopField klassField; | |
| 42 | |
| 43 static { | |
| 44 VM.registerVMInitializedObserver(new Observer() { | |
| 45 public void update(Observable o, Object data) { | |
| 46 initialize(VM.getVM().getTypeDataBase()); | |
| 47 } | |
| 48 }); | |
| 49 } | |
| 50 | |
| 51 private static void initialize(TypeDataBase db) { | |
| 52 Type type = db.lookupType("oopDesc"); | |
| 53 | |
|
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ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
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diff
changeset
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54 if (VM.getVM().isCompressedOopsEnabled()) { |
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ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
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diff
changeset
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55 klassField = type.getNarrowOopField("_metadata._compressed_klass"); |
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ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
56 } else { |
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ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
57 klassField = type.getOopField("_metadata._klass"); |
|
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
58 } |
| 0 | 59 } |
| 60 | |
| 61 public static boolean oopLooksValid(OopHandle oop) { | |
| 62 if (oop == null) { | |
| 63 return false; | |
| 64 } | |
| 65 if (!VM.getVM().getUniverse().isIn(oop)) { | |
| 66 return false; | |
| 67 } | |
| 68 try { | |
| 69 for (int i = 0; i < 4; ++i) { | |
| 70 OopHandle next = klassField.getValue(oop); | |
| 71 if (next == null) { | |
| 72 return false; | |
| 73 } | |
| 74 if (next.equals(oop)) { | |
| 75 return true; | |
| 76 } | |
| 77 oop = next; | |
| 78 } | |
| 79 return false; | |
| 80 } | |
| 81 catch (AddressException e) { | |
| 82 return false; | |
| 83 } | |
| 84 } | |
| 85 } |