1 /*
2 * Copyright (c) 1997, 2012, 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 #include "precompiled.hpp"
26 #include "compiler/compileBroker.hpp"
27 #include "gc_implementation/shared/markSweep.inline.hpp"
28 #include "gc_interface/collectedHeap.inline.hpp"
29 #include "oops/methodData.hpp"
30 #include "oops/objArrayKlass.inline.hpp"
31 #include "oops/oop.inline.hpp"
32
33 unsigned int MarkSweep::_total_invocations = 0;
34
35 Stack<oop, mtGC> MarkSweep::_marking_stack;
36 Stack<ObjArrayTask, mtGC> MarkSweep::_objarray_stack;
37
38 Stack<oop, mtGC> MarkSweep::_preserved_oop_stack;
39 Stack<markOop, mtGC> MarkSweep::_preserved_mark_stack;
40 size_t MarkSweep::_preserved_count = 0;
41 size_t MarkSweep::_preserved_count_max = 0;
42 PreservedMark* MarkSweep::_preserved_marks = NULL;
43 ReferenceProcessor* MarkSweep::_ref_processor = NULL;
44
45 MarkSweep::FollowRootClosure MarkSweep::follow_root_closure;
46 CodeBlobToOopClosure MarkSweep::follow_code_root_closure(&MarkSweep::follow_root_closure, /*do_marking=*/ true);
47
48 void MarkSweep::FollowRootClosure::do_oop(oop* p) { follow_root(p); }
49 void MarkSweep::FollowRootClosure::do_oop(narrowOop* p) { follow_root(p); }
50
51 MarkSweep::MarkAndPushClosure MarkSweep::mark_and_push_closure;
52 MarkSweep::FollowKlassClosure MarkSweep::follow_klass_closure;
53 MarkSweep::AdjustKlassClosure MarkSweep::adjust_klass_closure;
54
55 void MarkSweep::MarkAndPushClosure::do_oop(oop* p) { mark_and_push(p); }
56 void MarkSweep::MarkAndPushClosure::do_oop(narrowOop* p) { mark_and_push(p); }
57
58 void MarkSweep::FollowKlassClosure::do_klass(Klass* klass) {
59 klass->oops_do(&MarkSweep::mark_and_push_closure);
60 }
61 void MarkSweep::AdjustKlassClosure::do_klass(Klass* klass) {
62 klass->oops_do(&MarkSweep::adjust_pointer_closure);
63 }
64
65 void MarkSweep::follow_klass(Klass* klass) {
66 ClassLoaderData* cld = klass->class_loader_data();
67 // The actual processing of the klass is done when we
68 // traverse the list of Klasses in the class loader data.
69 MarkSweep::follow_class_loader(cld);
70 }
71
72 void MarkSweep::adjust_klass(Klass* klass) {
73 ClassLoaderData* cld = klass->class_loader_data();
74 // The actual processing of the klass is done when we
75 // traverse the list of Klasses in the class loader data.
76 MarkSweep::adjust_class_loader(cld);
77 }
78
79 void MarkSweep::follow_class_loader(ClassLoaderData* cld) {
80 cld->oops_do(&MarkSweep::mark_and_push_closure, &MarkSweep::follow_klass_closure, true);
81 }
82
83 void MarkSweep::adjust_class_loader(ClassLoaderData* cld) {
84 cld->oops_do(&MarkSweep::adjust_pointer_closure, &MarkSweep::adjust_klass_closure, true);
85 }
86
87
88 void MarkSweep::follow_stack() {
89 do {
90 while (!_marking_stack.is_empty()) {
91 oop obj = _marking_stack.pop();
92 assert (obj->is_gc_marked(), "p must be marked");
93 obj->follow_contents();
94 }
95 // Process ObjArrays one at a time to avoid marking stack bloat.
96 if (!_objarray_stack.is_empty()) {
97 ObjArrayTask task = _objarray_stack.pop();
98 ObjArrayKlass* const k = (ObjArrayKlass*)task.obj()->klass();
99 k->oop_follow_contents(task.obj(), task.index());
100 }
101 } while (!_marking_stack.is_empty() || !_objarray_stack.is_empty());
102 }
103
104 MarkSweep::FollowStackClosure MarkSweep::follow_stack_closure;
105
106 void MarkSweep::FollowStackClosure::do_void() { follow_stack(); }
107
108 // We preserve the mark which should be replaced at the end and the location
109 // that it will go. Note that the object that this markOop belongs to isn't
110 // currently at that address but it will be after phase4
111 void MarkSweep::preserve_mark(oop obj, markOop mark) {
112 // We try to store preserved marks in the to space of the new generation since
113 // this is storage which should be available. Most of the time this should be
114 // sufficient space for the marks we need to preserve but if it isn't we fall
115 // back to using Stacks to keep track of the overflow.
116 if (_preserved_count < _preserved_count_max) {
117 _preserved_marks[_preserved_count++].init(obj, mark);
118 } else {
119 _preserved_mark_stack.push(mark);
120 _preserved_oop_stack.push(obj);
121 }
122 }
123
124 MarkSweep::AdjustPointerClosure MarkSweep::adjust_pointer_closure;
125
126 void MarkSweep::AdjustPointerClosure::do_oop(oop* p) { adjust_pointer(p); }
127 void MarkSweep::AdjustPointerClosure::do_oop(narrowOop* p) { adjust_pointer(p); }
128
129 void MarkSweep::adjust_marks() {
130 assert( _preserved_oop_stack.size() == _preserved_mark_stack.size(),
131 "inconsistent preserved oop stacks");
132
133 // adjust the oops we saved earlier
134 for (size_t i = 0; i < _preserved_count; i++) {
135 _preserved_marks[i].adjust_pointer();
136 }
137
138 // deal with the overflow stack
139 StackIterator<oop, mtGC> iter(_preserved_oop_stack);
140 while (!iter.is_empty()) {
141 oop* p = iter.next_addr();
142 adjust_pointer(p);
143 }
144 }
145
146 void MarkSweep::restore_marks() {
147 assert(_preserved_oop_stack.size() == _preserved_mark_stack.size(),
148 "inconsistent preserved oop stacks");
149 if (PrintGC && Verbose) {
150 gclog_or_tty->print_cr("Restoring %d marks",
151 _preserved_count + _preserved_oop_stack.size());
152 }
153
154 // restore the marks we saved earlier
155 for (size_t i = 0; i < _preserved_count; i++) {
156 _preserved_marks[i].restore();
157 }
158
159 // deal with the overflow
160 while (!_preserved_oop_stack.is_empty()) {
161 oop obj = _preserved_oop_stack.pop();
162 markOop mark = _preserved_mark_stack.pop();
163 obj->set_mark(mark);
164 }
165 }
166
167 MarkSweep::IsAliveClosure MarkSweep::is_alive;
168
169 void MarkSweep::IsAliveClosure::do_object(oop p) { ShouldNotReachHere(); }
170 bool MarkSweep::IsAliveClosure::do_object_b(oop p) { return p->is_gc_marked(); }
171
172 MarkSweep::KeepAliveClosure MarkSweep::keep_alive;
173
174 void MarkSweep::KeepAliveClosure::do_oop(oop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
175 void MarkSweep::KeepAliveClosure::do_oop(narrowOop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
176
177 void marksweep_init() { /* empty */ }
178
179 #ifndef PRODUCT
180
181 void MarkSweep::trace(const char* msg) {
182 if (TraceMarkSweep)
183 gclog_or_tty->print("%s", msg);
184 }
185
186 #endif