Thu, 05 Jun 2008 15:57:56 -0700
6711316: Open source the Garbage-First garbage collector
Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr
1 /*
2 * Copyright 2000-2006 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 */
25 inline void MarkSweep::mark_object(oop obj) {
26 #ifndef SERIALGC
27 if (UseParallelOldGC && VerifyParallelOldWithMarkSweep) {
28 assert(PSParallelCompact::mark_bitmap()->is_marked(obj),
29 "Should be marked in the marking bitmap");
30 }
31 #endif // SERIALGC
33 // some marks may contain information we need to preserve so we store them away
34 // and overwrite the mark. We'll restore it at the end of markSweep.
35 markOop mark = obj->mark();
36 obj->set_mark(markOopDesc::prototype()->set_marked());
38 if (mark->must_be_preserved(obj)) {
39 preserve_mark(obj, mark);
40 }
41 }
43 template <class T> inline void MarkSweep::follow_root(T* p) {
44 assert(!Universe::heap()->is_in_reserved(p),
45 "roots shouldn't be things within the heap");
46 #ifdef VALIDATE_MARK_SWEEP
47 if (ValidateMarkSweep) {
48 guarantee(!_root_refs_stack->contains(p), "should only be in here once");
49 _root_refs_stack->push(p);
50 }
51 #endif
52 T heap_oop = oopDesc::load_heap_oop(p);
53 if (!oopDesc::is_null(heap_oop)) {
54 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
55 if (!obj->mark()->is_marked()) {
56 mark_object(obj);
57 obj->follow_contents();
58 }
59 }
60 follow_stack();
61 }
63 template <class T> inline void MarkSweep::mark_and_follow(T* p) {
64 // assert(Universe::heap()->is_in_reserved(p), "should be in object space");
65 T heap_oop = oopDesc::load_heap_oop(p);
66 if (!oopDesc::is_null(heap_oop)) {
67 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
68 if (!obj->mark()->is_marked()) {
69 mark_object(obj);
70 obj->follow_contents();
71 }
72 }
73 }
75 template <class T> inline void MarkSweep::mark_and_push(T* p) {
76 // assert(Universe::heap()->is_in_reserved(p), "should be in object space");
77 T heap_oop = oopDesc::load_heap_oop(p);
78 if (!oopDesc::is_null(heap_oop)) {
79 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
80 if (!obj->mark()->is_marked()) {
81 mark_object(obj);
82 _marking_stack->push(obj);
83 }
84 }
85 }
87 template <class T> inline void MarkSweep::adjust_pointer(T* p, bool isroot) {
88 T heap_oop = oopDesc::load_heap_oop(p);
89 if (!oopDesc::is_null(heap_oop)) {
90 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
91 oop new_obj = oop(obj->mark()->decode_pointer());
92 assert(new_obj != NULL || // is forwarding ptr?
93 obj->mark() == markOopDesc::prototype() || // not gc marked?
94 (UseBiasedLocking && obj->mark()->has_bias_pattern()) ||
95 // not gc marked?
96 obj->is_shared(), // never forwarded?
97 "should be forwarded");
98 if (new_obj != NULL) {
99 assert(Universe::heap()->is_in_reserved(new_obj),
100 "should be in object space");
101 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
102 }
103 }
104 VALIDATE_MARK_SWEEP_ONLY(track_adjusted_pointer(p, isroot));
105 }
107 template <class T> inline void MarkSweep::KeepAliveClosure::do_oop_work(T* p) {
108 #ifdef VALIDATE_MARK_SWEEP
109 if (ValidateMarkSweep) {
110 if (!Universe::heap()->is_in_reserved(p)) {
111 _root_refs_stack->push(p);
112 } else {
113 _other_refs_stack->push(p);
114 }
115 }
116 #endif
117 mark_and_push(p);
118 }