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