1 /*
2 * Copyright (c) 2001, 2015, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
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23 */
24
25 #ifndef SHARE_VM_GC_SHARED_GENOOPCLOSURES_INLINE_HPP
26 #define SHARE_VM_GC_SHARED_GENOOPCLOSURES_INLINE_HPP
27
28 #include "gc/serial/defNewGeneration.hpp"
29 #include "gc/shared/cardTableRS.hpp"
30 #include "gc/shared/genCollectedHeap.hpp"
31 #include "gc/shared/genOopClosures.hpp"
32 #include "gc/shared/generation.hpp"
33 #include "gc/shared/space.hpp"
34
35 inline OopsInGenClosure::OopsInGenClosure(Generation* gen) :
36 ExtendedOopClosure(gen->ref_processor()), _gen(NULL), _rs(NULL) {
37 set_generation(gen);
38 }
39
40 inline void OopsInGenClosure::set_generation(Generation* gen) {
41 assert(_gen == NULL, "Generation already initialized");
42 _gen = gen;
43 _gen_boundary = _gen->reserved().start();
44 // Barrier set for the heap, must be set after heap is initialized
45 if (_rs == NULL) {
46 _rs = GenCollectedHeap::heap()->rem_set();
47 }
48 }
49
50 inline void OopsInGenClosure::assert_generation(Generation* gen) {
51 assert(_gen == gen, "Generations mismatch. Fix it now!!");
52 }
53
54 template <class T> inline void OopsInGenClosure::do_barrier(T* p) {
55 assert(generation()->is_in_reserved(p), "expected ref in generation");
56 T heap_oop = oopDesc::load_heap_oop(p);
57 assert(!oopDesc::is_null(heap_oop), "expected non-null oop");
58 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
59 // If p points to a younger generation, mark the card.
60 if ((HeapWord*)obj < _gen_boundary) {
61 _rs->inline_write_ref_field_gc(p, obj);
62 }
63 }
64
65 template <class T> inline void OopsInGenClosure::par_do_barrier(T* p) {
66 assert(generation()->is_in_reserved(p), "expected ref in generation");
67 T heap_oop = oopDesc::load_heap_oop(p);
68 assert(!oopDesc::is_null(heap_oop), "expected non-null oop");
69 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
70 // If p points to a younger generation, mark the card.
71 if ((HeapWord*)obj < gen_boundary()) {
72 rs()->write_ref_field_gc_par(p, obj);
73 }
74 }
75
76 inline void OopsInKlassOrGenClosure::do_klass_barrier() {
77 assert(_scanned_klass != NULL, "Must be");
78 _scanned_klass->record_modified_oops();
79 }
80
81 // NOTE! Any changes made here should also be made
82 // in FastScanClosure::do_oop_work()
83 template <class T> inline void ScanClosure::do_oop_work(T* p) {
84 T heap_oop = oopDesc::load_heap_oop(p);
85 // Should we copy the obj?
86 if (!oopDesc::is_null(heap_oop)) {
87 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
88 if ((HeapWord*)obj < _boundary) {
89 assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?");
90 oop new_obj = obj->is_forwarded() ? obj->forwardee()
91 : _g->copy_to_survivor_space(obj);
92 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
93 }
94
95 if (is_scanning_a_klass()) {
96 do_klass_barrier();
97 } else if (_gc_barrier) {
98 // Now call parent closure
99 do_barrier(p);
100 }
101 }
102 }
103
104 inline void ScanClosure::do_oop_nv(oop* p) { ScanClosure::do_oop_work(p); }
105 inline void ScanClosure::do_oop_nv(narrowOop* p) { ScanClosure::do_oop_work(p); }
106
107 // NOTE! Any changes made here should also be made
108 // in ScanClosure::do_oop_work()
109 template <class T> inline void FastScanClosure::do_oop_work(T* p) {
110 T heap_oop = oopDesc::load_heap_oop(p);
111 // Should we copy the obj?
112 if (!oopDesc::is_null(heap_oop)) {
113 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
114 if ((HeapWord*)obj < _boundary) {
115 assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?");
116 oop new_obj = obj->is_forwarded() ? obj->forwardee()
117 : _g->copy_to_survivor_space(obj);
118 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
119 if (is_scanning_a_klass()) {
120 do_klass_barrier();
121 } else if (_gc_barrier) {
122 // Now call parent closure
123 do_barrier(p);
124 }
125 }
126 }
127 }
128
129 inline void FastScanClosure::do_oop_nv(oop* p) { FastScanClosure::do_oop_work(p); }
130 inline void FastScanClosure::do_oop_nv(narrowOop* p) { FastScanClosure::do_oop_work(p); }
131
132 // Note similarity to ScanClosure; the difference is that
133 // the barrier set is taken care of outside this closure.
134 template <class T> inline void ScanWeakRefClosure::do_oop_work(T* p) {
135 assert(!oopDesc::is_null(*p), "null weak reference?");
136 oop obj = oopDesc::load_decode_heap_oop_not_null(p);
137 // weak references are sometimes scanned twice; must check
138 // that to-space doesn't already contain this object
139 if ((HeapWord*)obj < _boundary && !_g->to()->is_in_reserved(obj)) {
140 oop new_obj = obj->is_forwarded() ? obj->forwardee()
141 : _g->copy_to_survivor_space(obj);
142 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
143 }
144 }
145
146 inline void ScanWeakRefClosure::do_oop_nv(oop* p) { ScanWeakRefClosure::do_oop_work(p); }
147 inline void ScanWeakRefClosure::do_oop_nv(narrowOop* p) { ScanWeakRefClosure::do_oop_work(p); }
148
149 #endif // SHARE_VM_GC_SHARED_GENOOPCLOSURES_INLINE_HPP