Mercurial > hg > truffle
annotate src/share/vm/memory/referenceProcessor.hpp @ 3992:d1bdeef3e3e2
7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76
Summary: There is a race between one thread successfully forwarding and copying the klass mirror for the SoftReference class (including the static master clock) and another thread attempting to use the master clock while attempting to discover a soft reference object. Maintain a shadow copy of the soft reference master clock and use the shadow during reference discovery and reference processing.
Reviewed-by: tonyp, brutisso, ysr
author | johnc |
---|---|
date | Wed, 12 Oct 2011 10:25:51 -0700 |
parents | 4dfb2df418f2 |
children | bf2d2b8b1726 |
rev | line source |
---|---|
0 | 1 /* |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
2 * Copyright (c) 2001, 2011, 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
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1244
diff
changeset
|
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1244
diff
changeset
|
20 * or visit www.oracle.com if you need additional information or have any |
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
1244
diff
changeset
|
21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #ifndef SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP |
26 #define SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP | |
27 | |
28 #include "memory/referencePolicy.hpp" | |
29 #include "oops/instanceRefKlass.hpp" | |
30 | |
0 | 31 // ReferenceProcessor class encapsulates the per-"collector" processing |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
32 // of java.lang.Reference objects for GC. The interface is useful for supporting |
0 | 33 // a generational abstraction, in particular when there are multiple |
34 // generations that are being independently collected -- possibly | |
35 // concurrently and/or incrementally. Note, however, that the | |
36 // ReferenceProcessor class abstracts away from a generational setting | |
37 // by using only a heap interval (called "span" below), thus allowing | |
38 // its use in a straightforward manner in a general, non-generational | |
39 // setting. | |
40 // | |
41 // The basic idea is that each ReferenceProcessor object concerns | |
42 // itself with ("weak") reference processing in a specific "span" | |
43 // of the heap of interest to a specific collector. Currently, | |
44 // the span is a convex interval of the heap, but, efficiency | |
45 // apart, there seems to be no reason it couldn't be extended | |
46 // (with appropriate modifications) to any "non-convex interval". | |
47 | |
48 // forward references | |
49 class ReferencePolicy; | |
50 class AbstractRefProcTaskExecutor; | |
3979
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
51 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
52 // List of discovered references. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
53 class DiscoveredList { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
54 public: |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
55 DiscoveredList() : _len(0), _compressed_head(0), _oop_head(NULL) { } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
56 oop head() const { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
57 return UseCompressedOops ? oopDesc::decode_heap_oop(_compressed_head) : |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
58 _oop_head; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
59 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
60 HeapWord* adr_head() { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
61 return UseCompressedOops ? (HeapWord*)&_compressed_head : |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
62 (HeapWord*)&_oop_head; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
63 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
64 void set_head(oop o) { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
65 if (UseCompressedOops) { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
66 // Must compress the head ptr. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
67 _compressed_head = oopDesc::encode_heap_oop(o); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
68 } else { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
69 _oop_head = o; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
70 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
71 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
72 bool is_empty() const { return head() == NULL; } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
73 size_t length() { return _len; } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
74 void set_length(size_t len) { _len = len; } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
75 void inc_length(size_t inc) { _len += inc; assert(_len > 0, "Error"); } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
76 void dec_length(size_t dec) { _len -= dec; } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
77 private: |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
78 // Set value depending on UseCompressedOops. This could be a template class |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
79 // but then we have to fix all the instantiations and declarations that use this class. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
80 oop _oop_head; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
81 narrowOop _compressed_head; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
82 size_t _len; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
83 }; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
84 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
85 // Iterator for the list of discovered references. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
86 class DiscoveredListIterator { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
87 private: |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
88 DiscoveredList& _refs_list; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
89 HeapWord* _prev_next; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
90 oop _prev; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
91 oop _ref; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
92 HeapWord* _discovered_addr; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
93 oop _next; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
94 HeapWord* _referent_addr; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
95 oop _referent; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
96 OopClosure* _keep_alive; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
97 BoolObjectClosure* _is_alive; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
98 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
99 DEBUG_ONLY( |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
100 oop _first_seen; // cyclic linked list check |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
101 ) |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
102 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
103 NOT_PRODUCT( |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
104 size_t _processed; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
105 size_t _removed; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
106 ) |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
107 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
108 public: |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
109 inline DiscoveredListIterator(DiscoveredList& refs_list, |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
110 OopClosure* keep_alive, |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
111 BoolObjectClosure* is_alive): |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
112 _refs_list(refs_list), |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
113 _prev_next(refs_list.adr_head()), |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
114 _prev(NULL), |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
115 _ref(refs_list.head()), |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
116 #ifdef ASSERT |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
117 _first_seen(refs_list.head()), |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
118 #endif |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
119 #ifndef PRODUCT |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
120 _processed(0), |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
121 _removed(0), |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
122 #endif |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
123 _next(NULL), |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
124 _keep_alive(keep_alive), |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
125 _is_alive(is_alive) |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
126 { } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
127 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
128 // End Of List. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
129 inline bool has_next() const { return _ref != NULL; } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
130 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
131 // Get oop to the Reference object. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
132 inline oop obj() const { return _ref; } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
133 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
134 // Get oop to the referent object. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
135 inline oop referent() const { return _referent; } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
136 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
137 // Returns true if referent is alive. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
138 inline bool is_referent_alive() const { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
139 return _is_alive->do_object_b(_referent); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
140 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
141 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
142 // Loads data for the current reference. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
143 // The "allow_null_referent" argument tells us to allow for the possibility |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
144 // of a NULL referent in the discovered Reference object. This typically |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
145 // happens in the case of concurrent collectors that may have done the |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
146 // discovery concurrently, or interleaved, with mutator execution. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
147 void load_ptrs(DEBUG_ONLY(bool allow_null_referent)); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
148 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
149 // Move to the next discovered reference. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
150 inline void next() { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
151 _prev_next = _discovered_addr; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
152 _prev = _ref; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
153 move_to_next(); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
154 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
155 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
156 // Remove the current reference from the list |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
157 void remove(); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
158 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
159 // Make the Reference object active again. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
160 void make_active(); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
161 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
162 // Make the referent alive. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
163 inline void make_referent_alive() { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
164 if (UseCompressedOops) { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
165 _keep_alive->do_oop((narrowOop*)_referent_addr); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
166 } else { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
167 _keep_alive->do_oop((oop*)_referent_addr); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
168 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
169 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
170 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
171 // Update the discovered field. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
172 inline void update_discovered() { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
173 // First _prev_next ref actually points into DiscoveredList (gross). |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
174 if (UseCompressedOops) { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
175 if (!oopDesc::is_null(*(narrowOop*)_prev_next)) { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
176 _keep_alive->do_oop((narrowOop*)_prev_next); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
177 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
178 } else { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
179 if (!oopDesc::is_null(*(oop*)_prev_next)) { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
180 _keep_alive->do_oop((oop*)_prev_next); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
181 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
182 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
183 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
184 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
185 // NULL out referent pointer. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
186 void clear_referent(); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
187 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
188 // Statistics |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
189 NOT_PRODUCT( |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
190 inline size_t processed() const { return _processed; } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
191 inline size_t removed() const { return _removed; } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
192 ) |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
193 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
194 inline void move_to_next() { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
195 if (_ref == _next) { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
196 // End of the list. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
197 _ref = NULL; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
198 } else { |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
199 _ref = _next; |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
200 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
201 assert(_ref != _first_seen, "cyclic ref_list found"); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
202 NOT_PRODUCT(_processed++); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
203 } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
204 }; |
0 | 205 |
206 class ReferenceProcessor : public CHeapObj { | |
207 protected: | |
3917
eca1193ca245
4965777: GC changes to support use of discovered field for pending references
ysr
parents:
3915
diff
changeset
|
208 // Compatibility with pre-4965777 JDK's |
eca1193ca245
4965777: GC changes to support use of discovered field for pending references
ysr
parents:
3915
diff
changeset
|
209 static bool _pending_list_uses_discovered_field; |
3979
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
210 |
3992
d1bdeef3e3e2
7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76
johnc
parents:
3979
diff
changeset
|
211 // The SoftReference master timestamp clock |
d1bdeef3e3e2
7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76
johnc
parents:
3979
diff
changeset
|
212 static jlong _soft_ref_timestamp_clock; |
d1bdeef3e3e2
7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76
johnc
parents:
3979
diff
changeset
|
213 |
3979
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
214 MemRegion _span; // (right-open) interval of heap |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
215 // subject to wkref discovery |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
216 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
217 bool _discovering_refs; // true when discovery enabled |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
218 bool _discovery_is_atomic; // if discovery is atomic wrt |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
219 // other collectors in configuration |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
220 bool _discovery_is_mt; // true if reference discovery is MT. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
221 |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
222 // If true, setting "next" field of a discovered refs list requires |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
223 // write barrier(s). (Must be true if used in a collector in which |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
224 // elements of a discovered list may be moved during discovery: for |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
225 // example, a collector like Garbage-First that moves objects during a |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
226 // long-term concurrent marking phase that does weak reference |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
227 // discovery.) |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
228 bool _discovered_list_needs_barrier; |
0 | 229 |
3979
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
230 BarrierSet* _bs; // Cached copy of BarrierSet. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
231 bool _enqueuing_is_done; // true if all weak references enqueued |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
232 bool _processing_is_mt; // true during phases when |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
233 // reference processing is MT. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
234 int _next_id; // round-robin mod _num_q counter in |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
235 // support of work distribution |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
236 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
237 // For collectors that do not keep GC liveness information |
0 | 238 // in the object header, this field holds a closure that |
239 // helps the reference processor determine the reachability | |
3979
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
240 // of an oop. It is currently initialized to NULL for all |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
241 // collectors except for CMS and G1. |
0 | 242 BoolObjectClosure* _is_alive_non_header; |
243 | |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
244 // Soft ref clearing policies |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
245 // . the default policy |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
246 static ReferencePolicy* _default_soft_ref_policy; |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
247 // . the "clear all" policy |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
248 static ReferencePolicy* _always_clear_soft_ref_policy; |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
249 // . the current policy below is either one of the above |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
250 ReferencePolicy* _current_soft_ref_policy; |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
251 |
0 | 252 // The discovered ref lists themselves |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
253 |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1552
diff
changeset
|
254 // The active MT'ness degree of the queues below |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
255 int _num_q; |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1552
diff
changeset
|
256 // The maximum MT'ness degree of the queues below |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1552
diff
changeset
|
257 int _max_num_q; |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
258 // Arrays of lists of oops, one per thread |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
259 DiscoveredList* _discoveredSoftRefs; |
0 | 260 DiscoveredList* _discoveredWeakRefs; |
261 DiscoveredList* _discoveredFinalRefs; | |
262 DiscoveredList* _discoveredPhantomRefs; | |
263 | |
264 public: | |
3979
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
265 static int number_of_subclasses_of_ref() { return (REF_PHANTOM - REF_OTHER); } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
266 |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
267 int num_q() { return _num_q; } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
268 int max_num_q() { return _max_num_q; } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
269 void set_active_mt_degree(int v) { _num_q = v; } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
270 DiscoveredList* discovered_soft_refs() { return _discoveredSoftRefs; } |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
271 |
457
27a80744a83b
6778647: snap(), snap_policy() should be renamed setup(), setup_policy()
ysr
parents:
453
diff
changeset
|
272 ReferencePolicy* setup_policy(bool always_clear) { |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
273 _current_soft_ref_policy = always_clear ? |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
274 _always_clear_soft_ref_policy : _default_soft_ref_policy; |
457
27a80744a83b
6778647: snap(), snap_policy() should be renamed setup(), setup_policy()
ysr
parents:
453
diff
changeset
|
275 _current_soft_ref_policy->setup(); // snapshot the policy threshold |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
276 return _current_soft_ref_policy; |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
277 } |
0 | 278 |
279 // Process references with a certain reachability level. | |
280 void process_discovered_reflist(DiscoveredList refs_lists[], | |
281 ReferencePolicy* policy, | |
282 bool clear_referent, | |
283 BoolObjectClosure* is_alive, | |
284 OopClosure* keep_alive, | |
285 VoidClosure* complete_gc, | |
286 AbstractRefProcTaskExecutor* task_executor); | |
287 | |
288 void process_phaseJNI(BoolObjectClosure* is_alive, | |
289 OopClosure* keep_alive, | |
290 VoidClosure* complete_gc); | |
291 | |
292 // Work methods used by the method process_discovered_reflist | |
293 // Phase1: keep alive all those referents that are otherwise | |
294 // dead but which must be kept alive by policy (and their closure). | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
295 void process_phase1(DiscoveredList& refs_list, |
0 | 296 ReferencePolicy* policy, |
297 BoolObjectClosure* is_alive, | |
298 OopClosure* keep_alive, | |
299 VoidClosure* complete_gc); | |
300 // Phase2: remove all those references whose referents are | |
301 // reachable. | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
302 inline void process_phase2(DiscoveredList& refs_list, |
0 | 303 BoolObjectClosure* is_alive, |
304 OopClosure* keep_alive, | |
305 VoidClosure* complete_gc) { | |
306 if (discovery_is_atomic()) { | |
307 // complete_gc is ignored in this case for this phase | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
308 pp2_work(refs_list, is_alive, keep_alive); |
0 | 309 } else { |
310 assert(complete_gc != NULL, "Error"); | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
311 pp2_work_concurrent_discovery(refs_list, is_alive, |
0 | 312 keep_alive, complete_gc); |
313 } | |
314 } | |
315 // Work methods in support of process_phase2 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
316 void pp2_work(DiscoveredList& refs_list, |
0 | 317 BoolObjectClosure* is_alive, |
318 OopClosure* keep_alive); | |
319 void pp2_work_concurrent_discovery( | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
320 DiscoveredList& refs_list, |
0 | 321 BoolObjectClosure* is_alive, |
322 OopClosure* keep_alive, | |
323 VoidClosure* complete_gc); | |
324 // Phase3: process the referents by either clearing them | |
325 // or keeping them alive (and their closure) | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
326 void process_phase3(DiscoveredList& refs_list, |
0 | 327 bool clear_referent, |
328 BoolObjectClosure* is_alive, | |
329 OopClosure* keep_alive, | |
330 VoidClosure* complete_gc); | |
331 | |
332 // Enqueue references with a certain reachability level | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
333 void enqueue_discovered_reflist(DiscoveredList& refs_list, HeapWord* pending_list_addr); |
0 | 334 |
335 // "Preclean" all the discovered reference lists | |
336 // by removing references with strongly reachable referents. | |
337 // The first argument is a predicate on an oop that indicates | |
338 // its (strong) reachability and the second is a closure that | |
339 // may be used to incrementalize or abort the precleaning process. | |
340 // The caller is responsible for taking care of potential | |
341 // interference with concurrent operations on these lists | |
342 // (or predicates involved) by other threads. Currently | |
1190
4788266644c1
6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context")
jmasa
parents:
457
diff
changeset
|
343 // only used by the CMS collector. should_unload_classes is |
4788266644c1
6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context")
jmasa
parents:
457
diff
changeset
|
344 // used to aid assertion checking when classes are collected. |
0 | 345 void preclean_discovered_references(BoolObjectClosure* is_alive, |
346 OopClosure* keep_alive, | |
347 VoidClosure* complete_gc, | |
1190
4788266644c1
6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context")
jmasa
parents:
457
diff
changeset
|
348 YieldClosure* yield, |
4788266644c1
6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context")
jmasa
parents:
457
diff
changeset
|
349 bool should_unload_classes); |
0 | 350 |
351 // Delete entries in the discovered lists that have | |
352 // either a null referent or are not active. Such | |
353 // Reference objects can result from the clearing | |
354 // or enqueueing of Reference objects concurrent | |
355 // with their discovery by a (concurrent) collector. | |
356 // For a definition of "active" see java.lang.ref.Reference; | |
357 // Refs are born active, become inactive when enqueued, | |
358 // and never become active again. The state of being | |
359 // active is encoded as follows: A Ref is active | |
360 // if and only if its "next" field is NULL. | |
361 void clean_up_discovered_references(); | |
362 void clean_up_discovered_reflist(DiscoveredList& refs_list); | |
363 | |
364 // Returns the name of the discovered reference list | |
365 // occupying the i / _num_q slot. | |
366 const char* list_name(int i); | |
367 | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
368 void enqueue_discovered_reflists(HeapWord* pending_list_addr, AbstractRefProcTaskExecutor* task_executor); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
369 |
0 | 370 protected: |
3979
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
371 // Set the 'discovered' field of the given reference to |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
372 // the given value - emitting barriers depending upon |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
373 // the value of _discovered_list_needs_barrier. |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
374 void set_discovered(oop ref, oop value); |
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
375 |
0 | 376 // "Preclean" the given discovered reference list |
377 // by removing references with strongly reachable referents. | |
378 // Currently used in support of CMS only. | |
379 void preclean_discovered_reflist(DiscoveredList& refs_list, | |
380 BoolObjectClosure* is_alive, | |
381 OopClosure* keep_alive, | |
382 VoidClosure* complete_gc, | |
383 YieldClosure* yield); | |
384 | |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
385 // round-robin mod _num_q (not: _not_ mode _max_num_q) |
0 | 386 int next_id() { |
387 int id = _next_id; | |
388 if (++_next_id == _num_q) { | |
389 _next_id = 0; | |
390 } | |
391 return id; | |
392 } | |
393 DiscoveredList* get_discovered_list(ReferenceType rt); | |
394 inline void add_to_discovered_list_mt(DiscoveredList& refs_list, oop obj, | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
395 HeapWord* discovered_addr); |
0 | 396 void verify_ok_to_handle_reflists() PRODUCT_RETURN; |
397 | |
3915
c2bf0120ee5d
7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents:
2369
diff
changeset
|
398 void clear_discovered_references(DiscoveredList& refs_list); |
0 | 399 void abandon_partial_discovered_list(DiscoveredList& refs_list); |
400 | |
401 // Calculate the number of jni handles. | |
402 unsigned int count_jni_refs(); | |
403 | |
404 // Balances reference queues. | |
405 void balance_queues(DiscoveredList ref_lists[]); | |
406 | |
407 // Update (advance) the soft ref master clock field. | |
408 void update_soft_ref_master_clock(); | |
409 | |
410 public: | |
411 // constructor | |
412 ReferenceProcessor(): | |
413 _span((HeapWord*)NULL, (HeapWord*)NULL), | |
414 _discoveredSoftRefs(NULL), _discoveredWeakRefs(NULL), | |
415 _discoveredFinalRefs(NULL), _discoveredPhantomRefs(NULL), | |
416 _discovering_refs(false), | |
417 _discovery_is_atomic(true), | |
418 _enqueuing_is_done(false), | |
419 _discovery_is_mt(false), | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
420 _discovered_list_needs_barrier(false), |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
421 _bs(NULL), |
0 | 422 _is_alive_non_header(NULL), |
423 _num_q(0), | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1552
diff
changeset
|
424 _max_num_q(0), |
0 | 425 _processing_is_mt(false), |
426 _next_id(0) | |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
427 { } |
0 | 428 |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
429 // Default parameters give you a vanilla reference processor. |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
430 ReferenceProcessor(MemRegion span, |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
431 bool mt_processing = false, int mt_processing_degree = 1, |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
432 bool mt_discovery = false, int mt_discovery_degree = 1, |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
433 bool atomic_discovery = true, |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
434 BoolObjectClosure* is_alive_non_header = NULL, |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
435 bool discovered_list_needs_barrier = false); |
1244
745c853ee57f
6885297: java -XX:RefDiscoveryPolicy=2 or -XX:TLABWasteTargetPercent=0 cause VM crash
johnc
parents:
1190
diff
changeset
|
436 |
0 | 437 // RefDiscoveryPolicy values |
1244
745c853ee57f
6885297: java -XX:RefDiscoveryPolicy=2 or -XX:TLABWasteTargetPercent=0 cause VM crash
johnc
parents:
1190
diff
changeset
|
438 enum DiscoveryPolicy { |
0 | 439 ReferenceBasedDiscovery = 0, |
1244
745c853ee57f
6885297: java -XX:RefDiscoveryPolicy=2 or -XX:TLABWasteTargetPercent=0 cause VM crash
johnc
parents:
1190
diff
changeset
|
440 ReferentBasedDiscovery = 1, |
745c853ee57f
6885297: java -XX:RefDiscoveryPolicy=2 or -XX:TLABWasteTargetPercent=0 cause VM crash
johnc
parents:
1190
diff
changeset
|
441 DiscoveryPolicyMin = ReferenceBasedDiscovery, |
745c853ee57f
6885297: java -XX:RefDiscoveryPolicy=2 or -XX:TLABWasteTargetPercent=0 cause VM crash
johnc
parents:
1190
diff
changeset
|
442 DiscoveryPolicyMax = ReferentBasedDiscovery |
0 | 443 }; |
444 | |
445 static void init_statics(); | |
446 | |
447 public: | |
448 // get and set "is_alive_non_header" field | |
449 BoolObjectClosure* is_alive_non_header() { | |
450 return _is_alive_non_header; | |
451 } | |
452 void set_is_alive_non_header(BoolObjectClosure* is_alive_non_header) { | |
453 _is_alive_non_header = is_alive_non_header; | |
454 } | |
455 | |
456 // get and set span | |
457 MemRegion span() { return _span; } | |
458 void set_span(MemRegion span) { _span = span; } | |
459 | |
460 // start and stop weak ref discovery | |
3992
d1bdeef3e3e2
7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76
johnc
parents:
3979
diff
changeset
|
461 void enable_discovery(bool verify_disabled, bool check_no_refs); |
0 | 462 void disable_discovery() { _discovering_refs = false; } |
463 bool discovery_enabled() { return _discovering_refs; } | |
464 | |
465 // whether discovery is atomic wrt other collectors | |
466 bool discovery_is_atomic() const { return _discovery_is_atomic; } | |
467 void set_atomic_discovery(bool atomic) { _discovery_is_atomic = atomic; } | |
468 | |
3917
eca1193ca245
4965777: GC changes to support use of discovered field for pending references
ysr
parents:
3915
diff
changeset
|
469 // whether the JDK in which we are embedded is a pre-4965777 JDK, |
eca1193ca245
4965777: GC changes to support use of discovered field for pending references
ysr
parents:
3915
diff
changeset
|
470 // and thus whether or not it uses the discovered field to chain |
eca1193ca245
4965777: GC changes to support use of discovered field for pending references
ysr
parents:
3915
diff
changeset
|
471 // the entries in the pending list. |
eca1193ca245
4965777: GC changes to support use of discovered field for pending references
ysr
parents:
3915
diff
changeset
|
472 static bool pending_list_uses_discovered_field() { |
eca1193ca245
4965777: GC changes to support use of discovered field for pending references
ysr
parents:
3915
diff
changeset
|
473 return _pending_list_uses_discovered_field; |
eca1193ca245
4965777: GC changes to support use of discovered field for pending references
ysr
parents:
3915
diff
changeset
|
474 } |
eca1193ca245
4965777: GC changes to support use of discovered field for pending references
ysr
parents:
3915
diff
changeset
|
475 |
0 | 476 // whether discovery is done by multiple threads same-old-timeously |
477 bool discovery_is_mt() const { return _discovery_is_mt; } | |
478 void set_mt_discovery(bool mt) { _discovery_is_mt = mt; } | |
479 | |
480 // Whether we are in a phase when _processing_ is MT. | |
481 bool processing_is_mt() const { return _processing_is_mt; } | |
482 void set_mt_processing(bool mt) { _processing_is_mt = mt; } | |
483 | |
484 // whether all enqueuing of weak references is complete | |
485 bool enqueuing_is_done() { return _enqueuing_is_done; } | |
486 void set_enqueuing_is_done(bool v) { _enqueuing_is_done = v; } | |
487 | |
488 // iterate over oops | |
489 void weak_oops_do(OopClosure* f); // weak roots | |
490 | |
1833
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1552
diff
changeset
|
491 // Balance each of the discovered lists. |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1552
diff
changeset
|
492 void balance_all_queues(); |
8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
jmasa
parents:
1552
diff
changeset
|
493 |
0 | 494 // Discover a Reference object, using appropriate discovery criteria |
495 bool discover_reference(oop obj, ReferenceType rt); | |
496 | |
497 // Process references found during GC (called by the garbage collector) | |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
356
diff
changeset
|
498 void process_discovered_references(BoolObjectClosure* is_alive, |
0 | 499 OopClosure* keep_alive, |
500 VoidClosure* complete_gc, | |
501 AbstractRefProcTaskExecutor* task_executor); | |
502 | |
503 public: | |
504 // Enqueue references at end of GC (called by the garbage collector) | |
505 bool enqueue_discovered_references(AbstractRefProcTaskExecutor* task_executor = NULL); | |
506 | |
342
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
507 // If a discovery is in process that is being superceded, abandon it: all |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
508 // the discovered lists will be empty, and all the objects on them will |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
509 // have NULL discovered fields. Must be called only at a safepoint. |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
510 void abandon_partial_discovery(); |
37f87013dfd8
6711316: Open source the Garbage-First garbage collector
ysr
parents:
113
diff
changeset
|
511 |
0 | 512 // debugging |
513 void verify_no_references_recorded() PRODUCT_RETURN; | |
1995
8df09fb45352
7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent
ysr
parents:
1972
diff
changeset
|
514 void verify_referent(oop obj) PRODUCT_RETURN; |
0 | 515 |
516 // clear the discovered lists (unlinking each entry). | |
517 void clear_discovered_references() PRODUCT_RETURN; | |
518 }; | |
519 | |
520 // A utility class to disable reference discovery in | |
521 // the scope which contains it, for given ReferenceProcessor. | |
522 class NoRefDiscovery: StackObj { | |
523 private: | |
524 ReferenceProcessor* _rp; | |
525 bool _was_discovering_refs; | |
526 public: | |
527 NoRefDiscovery(ReferenceProcessor* rp) : _rp(rp) { | |
1789
a83b0246bb77
6934483: GCC 4.5 errors "suggest parentheses around something..." when compiling with -Werror and -Wall
twisti
parents:
1552
diff
changeset
|
528 _was_discovering_refs = _rp->discovery_enabled(); |
a83b0246bb77
6934483: GCC 4.5 errors "suggest parentheses around something..." when compiling with -Werror and -Wall
twisti
parents:
1552
diff
changeset
|
529 if (_was_discovering_refs) { |
0 | 530 _rp->disable_discovery(); |
531 } | |
532 } | |
533 | |
534 ~NoRefDiscovery() { | |
535 if (_was_discovering_refs) { | |
3979
4dfb2df418f2
6484982: G1: process references during evacuation pauses
johnc
parents:
3917
diff
changeset
|
536 _rp->enable_discovery(true /*verify_disabled*/, false /*check_no_refs*/); |
0 | 537 } |
538 } | |
539 }; | |
540 | |
541 | |
542 // A utility class to temporarily mutate the span of the | |
543 // given ReferenceProcessor in the scope that contains it. | |
544 class ReferenceProcessorSpanMutator: StackObj { | |
545 private: | |
546 ReferenceProcessor* _rp; | |
547 MemRegion _saved_span; | |
548 | |
549 public: | |
550 ReferenceProcessorSpanMutator(ReferenceProcessor* rp, | |
551 MemRegion span): | |
552 _rp(rp) { | |
553 _saved_span = _rp->span(); | |
554 _rp->set_span(span); | |
555 } | |
556 | |
557 ~ReferenceProcessorSpanMutator() { | |
558 _rp->set_span(_saved_span); | |
559 } | |
560 }; | |
561 | |
562 // A utility class to temporarily change the MT'ness of | |
563 // reference discovery for the given ReferenceProcessor | |
564 // in the scope that contains it. | |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
565 class ReferenceProcessorMTDiscoveryMutator: StackObj { |
0 | 566 private: |
567 ReferenceProcessor* _rp; | |
568 bool _saved_mt; | |
569 | |
570 public: | |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
571 ReferenceProcessorMTDiscoveryMutator(ReferenceProcessor* rp, |
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
572 bool mt): |
0 | 573 _rp(rp) { |
574 _saved_mt = _rp->discovery_is_mt(); | |
575 _rp->set_mt_discovery(mt); | |
576 } | |
577 | |
2369
92da084fefc9
6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents:
1995
diff
changeset
|
578 ~ReferenceProcessorMTDiscoveryMutator() { |
0 | 579 _rp->set_mt_discovery(_saved_mt); |
580 } | |
581 }; | |
582 | |
583 | |
584 // A utility class to temporarily change the disposition | |
585 // of the "is_alive_non_header" closure field of the | |
586 // given ReferenceProcessor in the scope that contains it. | |
587 class ReferenceProcessorIsAliveMutator: StackObj { | |
588 private: | |
589 ReferenceProcessor* _rp; | |
590 BoolObjectClosure* _saved_cl; | |
591 | |
592 public: | |
593 ReferenceProcessorIsAliveMutator(ReferenceProcessor* rp, | |
594 BoolObjectClosure* cl): | |
595 _rp(rp) { | |
596 _saved_cl = _rp->is_alive_non_header(); | |
597 _rp->set_is_alive_non_header(cl); | |
598 } | |
599 | |
600 ~ReferenceProcessorIsAliveMutator() { | |
601 _rp->set_is_alive_non_header(_saved_cl); | |
602 } | |
603 }; | |
604 | |
605 // A utility class to temporarily change the disposition | |
606 // of the "discovery_is_atomic" field of the | |
607 // given ReferenceProcessor in the scope that contains it. | |
608 class ReferenceProcessorAtomicMutator: StackObj { | |
609 private: | |
610 ReferenceProcessor* _rp; | |
611 bool _saved_atomic_discovery; | |
612 | |
613 public: | |
614 ReferenceProcessorAtomicMutator(ReferenceProcessor* rp, | |
615 bool atomic): | |
616 _rp(rp) { | |
617 _saved_atomic_discovery = _rp->discovery_is_atomic(); | |
618 _rp->set_atomic_discovery(atomic); | |
619 } | |
620 | |
621 ~ReferenceProcessorAtomicMutator() { | |
622 _rp->set_atomic_discovery(_saved_atomic_discovery); | |
623 } | |
624 }; | |
625 | |
626 | |
627 // A utility class to temporarily change the MT processing | |
628 // disposition of the given ReferenceProcessor instance | |
629 // in the scope that contains it. | |
630 class ReferenceProcessorMTProcMutator: StackObj { | |
631 private: | |
632 ReferenceProcessor* _rp; | |
633 bool _saved_mt; | |
634 | |
635 public: | |
636 ReferenceProcessorMTProcMutator(ReferenceProcessor* rp, | |
637 bool mt): | |
638 _rp(rp) { | |
639 _saved_mt = _rp->processing_is_mt(); | |
640 _rp->set_mt_processing(mt); | |
641 } | |
642 | |
643 ~ReferenceProcessorMTProcMutator() { | |
644 _rp->set_mt_processing(_saved_mt); | |
645 } | |
646 }; | |
647 | |
648 | |
649 // This class is an interface used to implement task execution for the | |
650 // reference processing. | |
651 class AbstractRefProcTaskExecutor { | |
652 public: | |
653 | |
654 // Abstract tasks to execute. | |
655 class ProcessTask; | |
656 class EnqueueTask; | |
657 | |
658 // Executes a task using worker threads. | |
659 virtual void execute(ProcessTask& task) = 0; | |
660 virtual void execute(EnqueueTask& task) = 0; | |
661 | |
662 // Switch to single threaded mode. | |
663 virtual void set_single_threaded_mode() { }; | |
664 }; | |
665 | |
666 // Abstract reference processing task to execute. | |
667 class AbstractRefProcTaskExecutor::ProcessTask { | |
668 protected: | |
669 ProcessTask(ReferenceProcessor& ref_processor, | |
670 DiscoveredList refs_lists[], | |
671 bool marks_oops_alive) | |
672 : _ref_processor(ref_processor), | |
673 _refs_lists(refs_lists), | |
674 _marks_oops_alive(marks_oops_alive) | |
675 { } | |
676 | |
677 public: | |
678 virtual void work(unsigned int work_id, BoolObjectClosure& is_alive, | |
679 OopClosure& keep_alive, | |
680 VoidClosure& complete_gc) = 0; | |
681 | |
682 // Returns true if a task marks some oops as alive. | |
683 bool marks_oops_alive() const | |
684 { return _marks_oops_alive; } | |
685 | |
686 protected: | |
687 ReferenceProcessor& _ref_processor; | |
688 DiscoveredList* _refs_lists; | |
689 const bool _marks_oops_alive; | |
690 }; | |
691 | |
692 // Abstract reference processing task to execute. | |
693 class AbstractRefProcTaskExecutor::EnqueueTask { | |
694 protected: | |
695 EnqueueTask(ReferenceProcessor& ref_processor, | |
696 DiscoveredList refs_lists[], | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
697 HeapWord* pending_list_addr, |
0 | 698 int n_queues) |
699 : _ref_processor(ref_processor), | |
700 _refs_lists(refs_lists), | |
701 _pending_list_addr(pending_list_addr), | |
702 _n_queues(n_queues) | |
703 { } | |
704 | |
705 public: | |
706 virtual void work(unsigned int work_id) = 0; | |
707 | |
708 protected: | |
709 ReferenceProcessor& _ref_processor; | |
710 DiscoveredList* _refs_lists; | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
711 HeapWord* _pending_list_addr; |
0 | 712 int _n_queues; |
713 }; | |
1972 | 714 |
715 #endif // SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP |