Mercurial > hg > graal-jvmci-8

comparison src/share/vm/oops/markOop.inline.hpp @ 0:a61af66fc99e jdk7-b24

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Initial load
author duke
date Sat, 01 Dec 2007 00:00:00 +0000
parents
children 37f87013dfd8
comparison
equal deleted inserted replaced
-1:000000000000 0:a61af66fc99e
1 /*
2 * Copyright 2006 Sun Microsystems, Inc. All Rights Reserved.
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 // Should this header be preserved during GC?
26 inline bool markOopDesc::must_be_preserved_with_bias(oop obj_containing_mark) const {
27 assert(UseBiasedLocking, "unexpected");
28 if (has_bias_pattern()) {
29 // Will reset bias at end of collection
30 // Mark words of biased and currently locked objects are preserved separately
31 return false;
32 }
33 markOop prototype_header = prototype_for_object(obj_containing_mark);
34 if (prototype_header->has_bias_pattern()) {
35 // Individual instance which has its bias revoked; must return
36 // true for correctness
37 return true;
38 }
39 return (!is_unlocked() || !has_no_hash());
40 }
41
42 // Should this header (including its age bits) be preserved in the
43 // case of a promotion failure during scavenge?
44 inline bool markOopDesc::must_be_preserved_with_bias_for_promotion_failure(oop obj_containing_mark) const {
45 assert(UseBiasedLocking, "unexpected");
46 // We don't explicitly save off the mark words of biased and
47 // currently-locked objects during scavenges, so if during a
48 // promotion failure we encounter either a biased mark word or a
49 // klass which still has a biasable prototype header, we have to
50 // preserve the mark word. This results in oversaving, but promotion
51 // failures are rare, and this avoids adding more complex logic to
52 // the scavengers to call new variants of
53 // BiasedLocking::preserve_marks() / restore_marks() in the middle
54 // of a scavenge when a promotion failure has first been detected.
55 if (has_bias_pattern() ||
56 prototype_for_object(obj_containing_mark)->has_bias_pattern()) {
57 return true;
58 }
59 return (this != prototype());
60 }
61
62 // Should this header (including its age bits) be preserved in the
63 // case of a scavenge in which CMS is the old generation?
64 inline bool markOopDesc::must_be_preserved_with_bias_for_cms_scavenge(klassOop klass_of_obj_containing_mark) const {
65 assert(UseBiasedLocking, "unexpected");
66 // CMS scavenges preserve mark words in similar fashion to promotion failures; see above
67 if (has_bias_pattern() ||
68 klass_of_obj_containing_mark->klass_part()->prototype_header()->has_bias_pattern()) {
69 return true;
70 }
71 return (this != prototype());
72 }
73
74 inline markOop markOopDesc::prototype_for_object(oop obj) {
75 #ifdef ASSERT
76 markOop prototype_header = obj->klass()->klass_part()->prototype_header();
77 assert(prototype_header == prototype() || prototype_header->has_bias_pattern(), "corrupt prototype header");
78 #endif
79 return obj->klass()->klass_part()->prototype_header();
80 }