1 /*
2 * Copyright (c) 2017, 2018 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.
22 *
23 */
24
25 #ifndef SHARE_VM_GC_G1_G1MARKSTACK_INLINE_HPP
26 #define SHARE_VM_GC_G1_G1MARKSTACK_INLINE_HPP
27
28 #include "gc/g1/g1Allocator.inline.hpp"
29 #include "gc/g1/g1ConcurrentMarkBitMap.inline.hpp"
30 #include "gc/g1/g1FullGCMarker.hpp"
31 #include "gc/g1/g1FullGCOopClosures.inline.hpp"
32 #include "gc/g1/g1StringDedup.hpp"
33 #include "gc/g1/g1StringDedupQueue.hpp"
34 #include "gc/shared/preservedMarks.inline.hpp"
35 #include "oops/access.inline.hpp"
36 #include "oops/compressedOops.inline.hpp"
37 #include "oops/oop.inline.hpp"
38 #include "utilities/debug.hpp"
39
40 inline bool G1FullGCMarker::mark_object(oop obj) {
41 // Not marking closed archive objects.
42 if (G1ArchiveAllocator::is_closed_archive_object(obj)) {
43 return false;
44 }
45
46 // Try to mark.
47 if (!_bitmap->par_mark(obj)) {
48 // Lost mark race.
49 return false;
50 }
51
52 // Marked by us, preserve if needed.
53 markOop mark = obj->mark_raw();
54 if (mark->must_be_preserved(obj) &&
55 !G1ArchiveAllocator::is_open_archive_object(obj)) {
56 preserved_stack()->push(obj, mark);
57 }
58
59 // Check if deduplicatable string.
60 if (G1StringDedup::is_enabled()) {
61 G1StringDedup::enqueue_from_mark(obj, _worker_id);
62 }
63 return true;
64 }
65
66 template <class T> inline void G1FullGCMarker::mark_and_push(T* p) {
67 T heap_oop = RawAccess<>::oop_load(p);
68 if (!CompressedOops::is_null(heap_oop)) {
69 oop obj = CompressedOops::decode_not_null(heap_oop);
70 if (mark_object(obj)) {
71 _oop_stack.push(obj);
72 assert(_bitmap->is_marked(obj), "Must be marked now - map self");
73 } else {
74 assert(_bitmap->is_marked(obj) || G1ArchiveAllocator::is_closed_archive_object(obj),
75 "Must be marked by other or closed archive object");
76 }
77 }
78 }
79
80 inline bool G1FullGCMarker::is_empty() {
81 return _oop_stack.is_empty() && _objarray_stack.is_empty();
82 }
83
84 inline bool G1FullGCMarker::pop_object(oop& oop) {
85 return _oop_stack.pop_overflow(oop) || _oop_stack.pop_local(oop);
86 }
87
88 inline void G1FullGCMarker::push_objarray(oop obj, size_t index) {
89 ObjArrayTask task(obj, index);
90 assert(task.is_valid(), "bad ObjArrayTask");
91 _objarray_stack.push(task);
92 }
93
94 inline bool G1FullGCMarker::pop_objarray(ObjArrayTask& arr) {
95 return _objarray_stack.pop_overflow(arr) || _objarray_stack.pop_local(arr);
96 }
97
98 inline void G1FullGCMarker::follow_array(objArrayOop array) {
99 follow_klass(array->klass());
100 // Don't push empty arrays to avoid unnecessary work.
101 if (array->length() > 0) {
102 push_objarray(array, 0);
103 }
104 }
105
106 void G1FullGCMarker::follow_array_chunk(objArrayOop array, int index) {
107 const int len = array->length();
108 const int beg_index = index;
109 assert(beg_index < len || len == 0, "index too large");
110
111 const int stride = MIN2(len - beg_index, (int) ObjArrayMarkingStride);
112 const int end_index = beg_index + stride;
113
114 // Push the continuation first to allow more efficient work stealing.
115 if (end_index < len) {
116 push_objarray(array, end_index);
117 }
118
119 array->oop_iterate_range(mark_closure(), beg_index, end_index);
120
121 if (VerifyDuringGC) {
122 _verify_closure.set_containing_obj(array);
123 array->oop_iterate_range(&_verify_closure, beg_index, end_index);
124 if (_verify_closure.failures()) {
125 assert(false, "Failed");
126 }
127 }
128 }
129
130 inline void G1FullGCMarker::follow_object(oop obj) {
131 assert(_bitmap->is_marked(obj), "should be marked");
132 if (obj->is_objArray()) {
133 // Handle object arrays explicitly to allow them to
134 // be split into chunks if needed.
135 follow_array((objArrayOop)obj);
136 } else {
137 obj->oop_iterate(mark_closure());
138 if (VerifyDuringGC) {
139 if (obj->is_instance() && InstanceKlass::cast(obj->klass())->is_reference_instance_klass()) {
140 return;
141 }
142 _verify_closure.set_containing_obj(obj);
143 obj->oop_iterate(&_verify_closure);
144 if (_verify_closure.failures()) {
145 log_warning(gc, verify)("Failed after %d", _verify_closure._cc);
146 assert(false, "Failed");
147 }
148 }
149 }
150 }
151
152 void G1FullGCMarker::drain_stack() {
153 do {
154 oop obj;
155 while (pop_object(obj)) {
156 assert(_bitmap->is_marked(obj), "must be marked");
157 follow_object(obj);
158 }
159 // Process ObjArrays one at a time to avoid marking stack bloat.
160 ObjArrayTask task;
161 if (pop_objarray(task)) {
162 follow_array_chunk(objArrayOop(task.obj()), task.index());
163 }
164 } while (!is_empty());
165 }
166
167 inline void G1FullGCMarker::follow_klass(Klass* k) {
168 oop op = k->klass_holder();
169 mark_and_push(&op);
170 }
171
172 inline void G1FullGCMarker::follow_cld(ClassLoaderData* cld) {
173 _cld_closure.do_cld(cld);
174 }
175
176 #endif