1 /*
2 * Copyright (c) 1997, 2013, 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/gcTimer.hpp"
28 #include "gc_implementation/shared/gcTrace.hpp"
29 #include "gc_implementation/shared/markSweep.inline.hpp"
30 #include "gc_interface/collectedHeap.inline.hpp"
31 #include "oops/methodData.hpp"
32 #include "oops/objArrayKlass.inline.hpp"
33 #include "oops/oop.inline.hpp"
34
35 uint MarkSweep::_total_invocations = 0;
36
37 Stack<oop, mtGC> MarkSweep::_marking_stack;
38 Stack<ObjArrayTask, mtGC> MarkSweep::_objarray_stack;
39
40 Stack<oop, mtGC> MarkSweep::_preserved_oop_stack;
41 Stack<markOop, mtGC> MarkSweep::_preserved_mark_stack;
42 size_t MarkSweep::_preserved_count = 0;
43 size_t MarkSweep::_preserved_count_max = 0;
44 PreservedMark* MarkSweep::_preserved_marks = NULL;
45 ReferenceProcessor* MarkSweep::_ref_processor = NULL;
46 STWGCTimer* MarkSweep::_gc_timer = NULL;
47 SerialOldTracer* MarkSweep::_gc_tracer = NULL;
48
49 MarkSweep::FollowRootClosure MarkSweep::follow_root_closure;
50 CodeBlobToOopClosure MarkSweep::follow_code_root_closure(&MarkSweep::follow_root_closure, /*do_marking=*/ true);
51
52 void MarkSweep::FollowRootClosure::do_oop(oop* p) { follow_root(p); }
53 void MarkSweep::FollowRootClosure::do_oop(narrowOop* p) { follow_root(p); }
54
55 MarkSweep::MarkAndPushClosure MarkSweep::mark_and_push_closure;
56 MarkSweep::FollowKlassClosure MarkSweep::follow_klass_closure;
57 MarkSweep::AdjustKlassClosure MarkSweep::adjust_klass_closure;
58
59 void MarkSweep::MarkAndPushClosure::do_oop(oop* p) { mark_and_push(p); }
60 void MarkSweep::MarkAndPushClosure::do_oop(narrowOop* p) { mark_and_push(p); }
61
62 void MarkSweep::FollowKlassClosure::do_klass(Klass* klass) {
63 klass->oops_do(&MarkSweep::mark_and_push_closure);
64 }
65 void MarkSweep::AdjustKlassClosure::do_klass(Klass* klass) {
66 klass->oops_do(&MarkSweep::adjust_pointer_closure);
67 }
68
69 void MarkSweep::follow_klass(Klass* klass) {
70 ClassLoaderData* cld = klass->class_loader_data();
71 // The actual processing of the klass is done when we
72 // traverse the list of Klasses in the class loader data.
73 MarkSweep::follow_class_loader(cld);
74 }
75
76 void MarkSweep::adjust_klass(Klass* klass) {
77 ClassLoaderData* cld = klass->class_loader_data();
78 // The actual processing of the klass is done when we
79 // traverse the list of Klasses in the class loader data.
80 MarkSweep::adjust_class_loader(cld);
81 }
82
83 void MarkSweep::follow_class_loader(ClassLoaderData* cld) {
84 cld->oops_do(&MarkSweep::mark_and_push_closure, &MarkSweep::follow_klass_closure, true);
85 }
86
87 void MarkSweep::adjust_class_loader(ClassLoaderData* cld) {
88 cld->oops_do(&MarkSweep::adjust_pointer_closure, &MarkSweep::adjust_klass_closure, true);
89 }
90
91
92 void MarkSweep::follow_stack() {
93 do {
94 while (!_marking_stack.is_empty()) {
95 oop obj = _marking_stack.pop();
96 assert (obj->is_gc_marked(), "p must be marked");
97 obj->follow_contents();
98 }
99 // Process ObjArrays one at a time to avoid marking stack bloat.
100 if (!_objarray_stack.is_empty()) {
101 ObjArrayTask task = _objarray_stack.pop();
102 ObjArrayKlass* k = (ObjArrayKlass*)task.obj()->klass();
103 k->oop_follow_contents(task.obj(), task.index());
104 }
105 } while (!_marking_stack.is_empty() || !_objarray_stack.is_empty());
106 }
107
108 MarkSweep::FollowStackClosure MarkSweep::follow_stack_closure;
109
110 void MarkSweep::FollowStackClosure::do_void() { follow_stack(); }
111
112 // We preserve the mark which should be replaced at the end and the location
113 // that it will go. Note that the object that this markOop belongs to isn't
114 // currently at that address but it will be after phase4
115 void MarkSweep::preserve_mark(oop obj, markOop mark) {
116 // We try to store preserved marks in the to space of the new generation since
117 // this is storage which should be available. Most of the time this should be
118 // sufficient space for the marks we need to preserve but if it isn't we fall
119 // back to using Stacks to keep track of the overflow.
120 if (_preserved_count < _preserved_count_max) {
121 _preserved_marks[_preserved_count++].init(obj, mark);
122 } else {
123 _preserved_mark_stack.push(mark);
124 _preserved_oop_stack.push(obj);
125 }
126 }
127
128 MarkSweep::AdjustPointerClosure MarkSweep::adjust_pointer_closure;
129
130 void MarkSweep::AdjustPointerClosure::do_oop(oop* p) { adjust_pointer(p); }
131 void MarkSweep::AdjustPointerClosure::do_oop(narrowOop* p) { adjust_pointer(p); }
132
133 void MarkSweep::adjust_marks() {
134 assert( _preserved_oop_stack.size() == _preserved_mark_stack.size(),
135 "inconsistent preserved oop stacks");
136
137 // adjust the oops we saved earlier
138 for (size_t i = 0; i < _preserved_count; i++) {
139 _preserved_marks[i].adjust_pointer();
140 }
141
142 // deal with the overflow stack
143 StackIterator<oop, mtGC> iter(_preserved_oop_stack);
144 while (!iter.is_empty()) {
145 oop* p = iter.next_addr();
146 adjust_pointer(p);
147 }
148 }
149
150 void MarkSweep::restore_marks() {
151 assert(_preserved_oop_stack.size() == _preserved_mark_stack.size(),
152 "inconsistent preserved oop stacks");
153 if (PrintGC && Verbose) {
154 gclog_or_tty->print_cr("Restoring %d marks",
155 _preserved_count + _preserved_oop_stack.size());
156 }
157
158 // restore the marks we saved earlier
159 for (size_t i = 0; i < _preserved_count; i++) {
160 _preserved_marks[i].restore();
161 }
162
163 // deal with the overflow
164 while (!_preserved_oop_stack.is_empty()) {
165 oop obj = _preserved_oop_stack.pop();
166 markOop mark = _preserved_mark_stack.pop();
167 obj->set_mark(mark);
168 }
169 }
170
171 MarkSweep::IsAliveClosure MarkSweep::is_alive;
172
173 bool MarkSweep::IsAliveClosure::do_object_b(oop p) { return p->is_gc_marked(); }
174
175 MarkSweep::KeepAliveClosure MarkSweep::keep_alive;
176
177 void MarkSweep::KeepAliveClosure::do_oop(oop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
178 void MarkSweep::KeepAliveClosure::do_oop(narrowOop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
179
180 void marksweep_init() {
181 MarkSweep::_gc_timer = new (ResourceObj::C_HEAP, mtGC) STWGCTimer();
182 MarkSweep::_gc_tracer = new (ResourceObj::C_HEAP, mtGC) SerialOldTracer();
183 }
184
185 #ifndef PRODUCT
186
187 void MarkSweep::trace(const char* msg) {
188 if (TraceMarkSweep)
189 gclog_or_tty->print("%s", msg);
190 }
191
192 #endif