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
51 void MarkSweep::FollowRootClosure::do_oop(oop* p) { follow_root(p); }
52 void MarkSweep::FollowRootClosure::do_oop(narrowOop* p) { follow_root(p); }
53
54 MarkSweep::MarkAndPushClosure MarkSweep::mark_and_push_closure;
55 MarkSweep::FollowKlassClosure MarkSweep::follow_klass_closure;
56 MarkSweep::AdjustKlassClosure MarkSweep::adjust_klass_closure;
57
58 void MarkSweep::MarkAndPushClosure::do_oop(oop* p) { mark_and_push(p); }
59 void MarkSweep::MarkAndPushClosure::do_oop(narrowOop* p) { mark_and_push(p); }
60
61 void MarkSweep::FollowKlassClosure::do_klass(Klass* klass) {
62 klass->oops_do(&MarkSweep::mark_and_push_closure);
63 }
64 void MarkSweep::AdjustKlassClosure::do_klass(Klass* klass) {
65 klass->oops_do(&MarkSweep::adjust_pointer_closure);
66 }
67
68 void MarkSweep::follow_class_loader(ClassLoaderData* cld) {
69 cld->oops_do(&MarkSweep::mark_and_push_closure, &MarkSweep::follow_klass_closure, true);
70 }
71
72 void MarkSweep::follow_stack() {
73 do {
74 while (!_marking_stack.is_empty()) {
75 oop obj = _marking_stack.pop();
76 assert (obj->is_gc_marked(), "p must be marked");
77 obj->follow_contents();
78 }
79 // Process ObjArrays one at a time to avoid marking stack bloat.
80 if (!_objarray_stack.is_empty()) {
81 ObjArrayTask task = _objarray_stack.pop();
82 ObjArrayKlass* k = (ObjArrayKlass*)task.obj()->klass();
83 k->oop_follow_contents(task.obj(), task.index());
84 }
85 } while (!_marking_stack.is_empty() || !_objarray_stack.is_empty());
86 }
87
88 MarkSweep::FollowStackClosure MarkSweep::follow_stack_closure;
89
90 void MarkSweep::FollowStackClosure::do_void() { follow_stack(); }
91
92 // We preserve the mark which should be replaced at the end and the location
93 // that it will go. Note that the object that this markOop belongs to isn't
94 // currently at that address but it will be after phase4
95 void MarkSweep::preserve_mark(oop obj, markOop mark) {
96 // We try to store preserved marks in the to space of the new generation since
97 // this is storage which should be available. Most of the time this should be
98 // sufficient space for the marks we need to preserve but if it isn't we fall
99 // back to using Stacks to keep track of the overflow.
100 if (_preserved_count < _preserved_count_max) {
101 _preserved_marks[_preserved_count++].init(obj, mark);
102 } else {
103 _preserved_mark_stack.push(mark);
104 _preserved_oop_stack.push(obj);
105 }
106 }
107
108 MarkSweep::AdjustPointerClosure MarkSweep::adjust_pointer_closure;
109
110 void MarkSweep::AdjustPointerClosure::do_oop(oop* p) { adjust_pointer(p); }
111 void MarkSweep::AdjustPointerClosure::do_oop(narrowOop* p) { adjust_pointer(p); }
112
113 void MarkSweep::adjust_marks() {
114 assert( _preserved_oop_stack.size() == _preserved_mark_stack.size(),
115 "inconsistent preserved oop stacks");
116
117 // adjust the oops we saved earlier
118 for (size_t i = 0; i < _preserved_count; i++) {
119 _preserved_marks[i].adjust_pointer();
120 }
121
122 // deal with the overflow stack
123 StackIterator<oop, mtGC> iter(_preserved_oop_stack);
124 while (!iter.is_empty()) {
125 oop* p = iter.next_addr();
126 adjust_pointer(p);
127 }
128 }
129
130 void MarkSweep::restore_marks() {
131 assert(_preserved_oop_stack.size() == _preserved_mark_stack.size(),
132 "inconsistent preserved oop stacks");
133 if (PrintGC && Verbose) {
134 gclog_or_tty->print_cr("Restoring %d marks",
135 _preserved_count + _preserved_oop_stack.size());
136 }
137
138 // restore the marks we saved earlier
139 for (size_t i = 0; i < _preserved_count; i++) {
140 _preserved_marks[i].restore();
141 }
142
143 // deal with the overflow
144 while (!_preserved_oop_stack.is_empty()) {
145 oop obj = _preserved_oop_stack.pop();
146 markOop mark = _preserved_mark_stack.pop();
147 obj->set_mark(mark);
148 }
149 }
150
151 MarkSweep::IsAliveClosure MarkSweep::is_alive;
152
153 bool MarkSweep::IsAliveClosure::do_object_b(oop p) { return p->is_gc_marked(); }
154
155 MarkSweep::KeepAliveClosure MarkSweep::keep_alive;
156
157 void MarkSweep::KeepAliveClosure::do_oop(oop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
158 void MarkSweep::KeepAliveClosure::do_oop(narrowOop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
159
160 void marksweep_init() {
161 MarkSweep::_gc_timer = new (ResourceObj::C_HEAP, mtGC) STWGCTimer();
162 MarkSweep::_gc_tracer = new (ResourceObj::C_HEAP, mtGC) SerialOldTracer();
163 }
164
165 #ifndef PRODUCT
166
167 void MarkSweep::trace(const char* msg) {
168 if (TraceMarkSweep)
169 gclog_or_tty->print("%s", msg);
170 }
171
172 #endif