1 /*
2 * Copyright (c) 2017, 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/g1StringDedup.hpp"
32 #include "gc/g1/g1StringDedupQueue.hpp"
33 #include "gc/shared/preservedMarks.inline.hpp"
34 #include "oops/access.inline.hpp"
35 #include "oops/compressedOops.inline.hpp"
36 #include "utilities/debug.hpp"
37
38 inline bool G1FullGCMarker::mark_object(oop obj) {
39 // Not marking closed archive objects.
40 if (G1ArchiveAllocator::is_closed_archive_object(obj)) {
41 return false;
42 }
43
44 // Try to mark.
45 if (!_bitmap->par_mark(obj)) {
46 // Lost mark race.
47 return false;
48 }
49
50 // Marked by us, preserve if needed.
51 markOop mark = obj->mark();
52 if (mark->must_be_preserved(obj) &&
53 !G1ArchiveAllocator::is_open_archive_object(obj)) {
54 preserved_stack()->push(obj, mark);
55 }
56
57 // Check if deduplicatable string.
58 if (G1StringDedup::is_enabled()) {
59 G1StringDedup::enqueue_from_mark(obj, _worker_id);
60 }
61 return true;
62 }
63
64 template <class T> inline void G1FullGCMarker::mark_and_push(T* p) {
65 T heap_oop = RawAccess<>::oop_load(p);
66 if (!CompressedOops::is_null(heap_oop)) {
67 oop obj = CompressedOops::decode_not_null(heap_oop);
68 if (mark_object(obj)) {
69 _oop_stack.push(obj);
70 assert(_bitmap->is_marked(obj), "Must be marked now - map self");
71 } else {
72 assert(_bitmap->is_marked(obj) || G1ArchiveAllocator::is_closed_archive_object(obj),
73 "Must be marked by other or closed archive object");
74 }
75 }
76 }
77
78 inline bool G1FullGCMarker::is_empty() {
79 return _oop_stack.is_empty() && _objarray_stack.is_empty();
80 }
81
82 inline bool G1FullGCMarker::pop_object(oop& oop) {
83 return _oop_stack.pop_overflow(oop) || _oop_stack.pop_local(oop);
84 }
85
86 inline void G1FullGCMarker::push_objarray(oop obj, size_t index) {
87 ObjArrayTask task(obj, index);
88 assert(task.is_valid(), "bad ObjArrayTask");
89 _objarray_stack.push(task);
90 }
91
92 inline bool G1FullGCMarker::pop_objarray(ObjArrayTask& arr) {
93 return _objarray_stack.pop_overflow(arr) || _objarray_stack.pop_local(arr);
94 }
95
96 inline void G1FullGCMarker::follow_array(objArrayOop array) {
97 follow_klass(array->klass());
98 // Don't push empty arrays to avoid unnecessary work.
99 if (array->length() > 0) {
100 push_objarray(array, 0);
101 }
102 }
103
104 void G1FullGCMarker::follow_array_chunk(objArrayOop array, int index) {
105 const int len = array->length();
106 const int beg_index = index;
107 assert(beg_index < len || len == 0, "index too large");
108
109 const int stride = MIN2(len - beg_index, (int) ObjArrayMarkingStride);
110 const int end_index = beg_index + stride;
111
112 // Push the continuation first to allow more efficient work stealing.
113 if (end_index < len) {
114 push_objarray(array, end_index);
115 }
116
117 array->oop_iterate_range(mark_closure(), beg_index, end_index);
118
119 if (VerifyDuringGC) {
120 _verify_closure.set_containing_obj(array);
121 NoHeaderExtendedOopClosure no(&_verify_closure);
122 array->oop_iterate_range(&no, beg_index, end_index);
123 if (_verify_closure.failures()) {
124 assert(false, "Failed");
125 }
126 }
127 }
128
129 inline void G1FullGCMarker::follow_object(oop obj) {
130 assert(_bitmap->is_marked(obj), "should be marked");
131 if (obj->is_objArray()) {
132 // Handle object arrays explicitly to allow them to
133 // be split into chunks if needed.
134 follow_array((objArrayOop)obj);
135 } else {
136 obj->oop_iterate(mark_closure());
137 if (VerifyDuringGC) {
138 if (obj->is_instance() && InstanceKlass::cast(obj->klass())->is_reference_instance_klass()) {
139 return;
140 }
141 _verify_closure.set_containing_obj(obj);
142 obj->oop_iterate_no_header(&_verify_closure);
143 if (_verify_closure.failures()) {
144 log_warning(gc, verify)("Failed after %d", _verify_closure._cc);
145 assert(false, "Failed");
146 }
147 }
148 }
149 }
150
151 void G1FullGCMarker::drain_stack() {
152 do {
153 oop obj;
154 while (pop_object(obj)) {
155 assert(_bitmap->is_marked(obj), "must be marked");
156 follow_object(obj);
157 }
158 // Process ObjArrays one at a time to avoid marking stack bloat.
159 ObjArrayTask task;
160 if (pop_objarray(task)) {
161 follow_array_chunk(objArrayOop(task.obj()), task.index());
162 }
163 } while (!is_empty());
164 }
165
166 inline void G1FullGCMarker::follow_klass(Klass* k) {
167 oop op = k->klass_holder();
168 mark_and_push(&op);
169 }
170
171 inline void G1FullGCMarker::follow_cld(ClassLoaderData* cld) {
172 _cld_closure.do_cld(cld);
173 }
174
175 #endif