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