Mercurial > hg > truffle
annotate src/share/vm/oops/markOop.inline.hpp @ 3377:2aa9ddbb9e60
7041789: 30% perf regression with c2/arm following 7017732
Summary: Implement a more accurate is_scavengable()
Reviewed-by: stefank, jcoomes, ysr
author | jmasa |
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date | Tue, 03 May 2011 10:30:34 -0700 |
parents | 74ee0db180fa |
children | da91efe96a93 |
rev | line source |
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0 | 1 /* |
1972 | 2 * Copyright (c) 2006, 2010, Oracle and/or its affiliates. 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 * | |
1552
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #ifndef SHARE_VM_OOPS_MARKOOP_INLINE_HPP |
26 #define SHARE_VM_OOPS_MARKOOP_INLINE_HPP | |
27 | |
28 #include "oops/klass.hpp" | |
29 #include "oops/klassOop.hpp" | |
30 #include "oops/markOop.hpp" | |
31 #include "runtime/globals.hpp" | |
32 | |
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33 // Should this header be preserved during GC (when biased locking is enabled)? |
0 | 34 inline bool markOopDesc::must_be_preserved_with_bias(oop obj_containing_mark) const { |
35 assert(UseBiasedLocking, "unexpected"); | |
36 if (has_bias_pattern()) { | |
37 // Will reset bias at end of collection | |
38 // Mark words of biased and currently locked objects are preserved separately | |
39 return false; | |
40 } | |
41 markOop prototype_header = prototype_for_object(obj_containing_mark); | |
42 if (prototype_header->has_bias_pattern()) { | |
43 // Individual instance which has its bias revoked; must return | |
44 // true for correctness | |
45 return true; | |
46 } | |
47 return (!is_unlocked() || !has_no_hash()); | |
48 } | |
49 | |
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50 // Should this header be preserved during GC? |
342 | 51 inline bool markOopDesc::must_be_preserved(oop obj_containing_mark) const { |
52 if (!UseBiasedLocking) | |
53 return (!is_unlocked() || !has_no_hash()); | |
54 return must_be_preserved_with_bias(obj_containing_mark); | |
55 } | |
56 | |
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57 // Should this header be preserved in the case of a promotion failure |
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58 // during scavenge (when biased locking is enabled)? |
0 | 59 inline bool markOopDesc::must_be_preserved_with_bias_for_promotion_failure(oop obj_containing_mark) const { |
60 assert(UseBiasedLocking, "unexpected"); | |
61 // We don't explicitly save off the mark words of biased and | |
62 // currently-locked objects during scavenges, so if during a | |
63 // promotion failure we encounter either a biased mark word or a | |
64 // klass which still has a biasable prototype header, we have to | |
65 // preserve the mark word. This results in oversaving, but promotion | |
66 // failures are rare, and this avoids adding more complex logic to | |
67 // the scavengers to call new variants of | |
68 // BiasedLocking::preserve_marks() / restore_marks() in the middle | |
69 // of a scavenge when a promotion failure has first been detected. | |
70 if (has_bias_pattern() || | |
71 prototype_for_object(obj_containing_mark)->has_bias_pattern()) { | |
72 return true; | |
73 } | |
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74 return (!is_unlocked() || !has_no_hash()); |
0 | 75 } |
76 | |
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77 // Should this header be preserved in the case of a promotion failure |
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78 // during scavenge? |
342 | 79 inline bool markOopDesc::must_be_preserved_for_promotion_failure(oop obj_containing_mark) const { |
80 if (!UseBiasedLocking) | |
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81 return (!is_unlocked() || !has_no_hash()); |
342 | 82 return must_be_preserved_with_bias_for_promotion_failure(obj_containing_mark); |
83 } | |
84 | |
85 | |
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86 // Same as must_be_preserved_with_bias_for_promotion_failure() except that |
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87 // it takes a klassOop argument, instead of the object of which this is the mark word. |
0 | 88 inline bool markOopDesc::must_be_preserved_with_bias_for_cms_scavenge(klassOop klass_of_obj_containing_mark) const { |
89 assert(UseBiasedLocking, "unexpected"); | |
90 // CMS scavenges preserve mark words in similar fashion to promotion failures; see above | |
91 if (has_bias_pattern() || | |
92 klass_of_obj_containing_mark->klass_part()->prototype_header()->has_bias_pattern()) { | |
93 return true; | |
94 } | |
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95 return (!is_unlocked() || !has_no_hash()); |
0 | 96 } |
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97 |
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98 // Same as must_be_preserved_for_promotion_failure() except that |
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99 // it takes a klassOop argument, instead of the object of which this is the mark word. |
342 | 100 inline bool markOopDesc::must_be_preserved_for_cms_scavenge(klassOop klass_of_obj_containing_mark) const { |
101 if (!UseBiasedLocking) | |
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102 return (!is_unlocked() || !has_no_hash()); |
342 | 103 return must_be_preserved_with_bias_for_cms_scavenge(klass_of_obj_containing_mark); |
104 } | |
0 | 105 |
106 inline markOop markOopDesc::prototype_for_object(oop obj) { | |
107 #ifdef ASSERT | |
108 markOop prototype_header = obj->klass()->klass_part()->prototype_header(); | |
109 assert(prototype_header == prototype() || prototype_header->has_bias_pattern(), "corrupt prototype header"); | |
110 #endif | |
111 return obj->klass()->klass_part()->prototype_header(); | |
112 } | |
1972 | 113 |
114 #endif // SHARE_VM_OOPS_MARKOOP_INLINE_HPP |