1 /*
2 * Copyright (c) 1997, 2015, 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/serial/markSweep.inline.hpp"
28 #include "gc/shared/collectedHeap.inline.hpp"
29 #include "gc/shared/gcTimer.hpp"
30 #include "gc/shared/gcTrace.hpp"
31 #include "gc/shared/specialized_oop_closures.hpp"
32 #include "memory/iterator.inline.hpp"
33 #include "oops/instanceKlass.inline.hpp"
34 #include "oops/instanceMirrorKlass.inline.hpp"
35 #include "oops/methodData.hpp"
36 #include "oops/objArrayKlass.inline.hpp"
37 #include "oops/oop.inline.hpp"
38
39 uint MarkSweep::_total_invocations = 0;
40
41 Stack<oop, mtGC> MarkSweep::_marking_stack;
42 Stack<ObjArrayTask, mtGC> MarkSweep::_objarray_stack;
43
44 Stack<oop, mtGC> MarkSweep::_preserved_oop_stack;
45 Stack<markOop, mtGC> MarkSweep::_preserved_mark_stack;
46 size_t MarkSweep::_preserved_count = 0;
47 size_t MarkSweep::_preserved_count_max = 0;
48 PreservedMark* MarkSweep::_preserved_marks = NULL;
49 ReferenceProcessor* MarkSweep::_ref_processor = NULL;
50 STWGCTimer* MarkSweep::_gc_timer = NULL;
51 SerialOldTracer* MarkSweep::_gc_tracer = NULL;
52
53 MarkSweep::FollowRootClosure MarkSweep::follow_root_closure;
54
55 void MarkSweep::FollowRootClosure::do_oop(oop* p) { follow_root(p); }
56 void MarkSweep::FollowRootClosure::do_oop(narrowOop* p) { follow_root(p); }
57
58 MarkAndPushClosure MarkSweep::mark_and_push_closure;
59 CLDToOopClosure MarkSweep::follow_cld_closure(&mark_and_push_closure);
60 CLDToOopClosure MarkSweep::adjust_cld_closure(&adjust_pointer_closure);
61
62 template <typename T>
63 void MarkAndPushClosure::do_oop_nv(T* p) { MarkSweep::mark_and_push(p); }
64 void MarkAndPushClosure::do_oop(oop* p) { do_oop_nv(p); }
65 void MarkAndPushClosure::do_oop(narrowOop* p) { do_oop_nv(p); }
66 bool MarkAndPushClosure::do_metadata() { return do_metadata_nv(); }
67 bool MarkAndPushClosure::do_metadata_nv() { return true; }
68 void MarkAndPushClosure::do_klass(Klass* k) { do_klass_nv(k); }
69 void MarkAndPushClosure::do_klass_nv(Klass* k) { MarkSweep::follow_klass(k); }
70 void MarkAndPushClosure::do_cld(ClassLoaderData* cld) { do_cld_nv(cld); }
71 void MarkAndPushClosure::do_cld_nv(ClassLoaderData* cld) { MarkSweep::follow_cld(cld); }
72
73 void MarkSweep::follow_array(objArrayOop array, int index) {
74 const int len = array->length();
75 const int beg_index = index;
76 assert(beg_index < len || len == 0, "index too large");
77
78 const int stride = MIN2(len - beg_index, (int) ObjArrayMarkingStride);
79 const int end_index = beg_index + stride;
80
81 array->oop_iterate_range(&mark_and_push_closure, beg_index, end_index);
82
83 if (end_index < len) {
84 MarkSweep::push_objarray(array, end_index); // Push the continuation.
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 follow_object(obj);
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 follow_array(objArrayOop(task.obj()), task.index());
99 }
100 } while (!_marking_stack.is_empty() || !_objarray_stack.is_empty());
101 }
102
103 MarkSweep::FollowStackClosure MarkSweep::follow_stack_closure;
104
105 void MarkSweep::FollowStackClosure::do_void() { follow_stack(); }
106
107 void PreservedMark::adjust_pointer() {
108 MarkSweep::adjust_pointer(&_obj);
109 }
110
111 void PreservedMark::restore() {
112 _obj->set_mark(_mark);
113 }
114
115 // We preserve the mark which should be replaced at the end and the location
116 // that it will go. Note that the object that this markOop belongs to isn't
117 // currently at that address but it will be after phase4
118 void MarkSweep::preserve_mark(oop obj, markOop mark) {
119 // We try to store preserved marks in the to space of the new generation since
120 // this is storage which should be available. Most of the time this should be
121 // sufficient space for the marks we need to preserve but if it isn't we fall
122 // back to using Stacks to keep track of the overflow.
123 if (_preserved_count < _preserved_count_max) {
124 _preserved_marks[_preserved_count++].init(obj, mark);
125 } else {
126 _preserved_mark_stack.push(mark);
127 _preserved_oop_stack.push(obj);
128 }
129 }
130
131 void MarkSweep::set_ref_processor(ReferenceProcessor* rp) {
132 _ref_processor = rp;
133 mark_and_push_closure.set_ref_processor(_ref_processor);
134 }
135
136 MarkSweep::AdjustPointerClosure MarkSweep::adjust_pointer_closure;
137
138 template <typename T>
139 void MarkSweep::AdjustPointerClosure::do_oop_nv(T* p) { adjust_pointer(p); }
140 void MarkSweep::AdjustPointerClosure::do_oop(oop* p) { do_oop_nv(p); }
141 void MarkSweep::AdjustPointerClosure::do_oop(narrowOop* p) { do_oop_nv(p); }
142
143 void MarkSweep::adjust_marks() {
144 assert( _preserved_oop_stack.size() == _preserved_mark_stack.size(),
145 "inconsistent preserved oop stacks");
146
147 // adjust the oops we saved earlier
148 for (size_t i = 0; i < _preserved_count; i++) {
149 _preserved_marks[i].adjust_pointer();
150 }
151
152 // deal with the overflow stack
153 StackIterator<oop, mtGC> iter(_preserved_oop_stack);
154 while (!iter.is_empty()) {
155 oop* p = iter.next_addr();
156 adjust_pointer(p);
157 }
158 }
159
160 void MarkSweep::restore_marks() {
161 assert(_preserved_oop_stack.size() == _preserved_mark_stack.size(),
162 "inconsistent preserved oop stacks");
163 if (PrintGC && Verbose) {
164 gclog_or_tty->print_cr("Restoring " SIZE_FORMAT " marks",
165 _preserved_count + _preserved_oop_stack.size());
166 }
167
168 // restore the marks we saved earlier
169 for (size_t i = 0; i < _preserved_count; i++) {
170 _preserved_marks[i].restore();
171 }
172
173 // deal with the overflow
174 while (!_preserved_oop_stack.is_empty()) {
175 oop obj = _preserved_oop_stack.pop();
176 markOop mark = _preserved_mark_stack.pop();
177 obj->set_mark(mark);
178 }
179 }
180
181 MarkSweep::IsAliveClosure MarkSweep::is_alive;
182
183 bool MarkSweep::IsAliveClosure::do_object_b(oop p) { return p->is_gc_marked() || is_archive_object(p); }
184
185 MarkSweep::KeepAliveClosure MarkSweep::keep_alive;
186
187 void MarkSweep::KeepAliveClosure::do_oop(oop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
188 void MarkSweep::KeepAliveClosure::do_oop(narrowOop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
189
190 void marksweep_init() {
191 MarkSweep::_gc_timer = new (ResourceObj::C_HEAP, mtGC) STWGCTimer();
192 MarkSweep::_gc_tracer = new (ResourceObj::C_HEAP, mtGC) SerialOldTracer();
193 }
194
195 int InstanceKlass::oop_ms_adjust_pointers(oop obj) {
196 int size = size_helper();
197 oop_oop_iterate_oop_maps<true>(obj, &MarkSweep::adjust_pointer_closure);
198 return size;
199 }
200
201 int InstanceMirrorKlass::oop_ms_adjust_pointers(oop obj) {
202 int size = oop_size(obj);
203 InstanceKlass::oop_ms_adjust_pointers(obj);
204
205 oop_oop_iterate_statics<true>(obj, &MarkSweep::adjust_pointer_closure);
206 return size;
207 }
208
209 int InstanceClassLoaderKlass::oop_ms_adjust_pointers(oop obj) {
210 return InstanceKlass::oop_ms_adjust_pointers(obj);
211 }
212
213 #ifdef ASSERT
214 template <class T> static void trace_reference_gc(const char *s, oop obj,
215 T* referent_addr,
216 T* next_addr,
217 T* discovered_addr) {
218 if(TraceReferenceGC && PrintGCDetails) {
219 gclog_or_tty->print_cr("%s obj " PTR_FORMAT, s, p2i(obj));
220 gclog_or_tty->print_cr(" referent_addr/* " PTR_FORMAT " / "
221 PTR_FORMAT, p2i(referent_addr),
222 p2i(referent_addr ?
223 (address)oopDesc::load_decode_heap_oop(referent_addr) : NULL));
224 gclog_or_tty->print_cr(" next_addr/* " PTR_FORMAT " / "
225 PTR_FORMAT, p2i(next_addr),
226 p2i(next_addr ? (address)oopDesc::load_decode_heap_oop(next_addr) : NULL));
227 gclog_or_tty->print_cr(" discovered_addr/* " PTR_FORMAT " / "
228 PTR_FORMAT, p2i(discovered_addr),
229 p2i(discovered_addr ?
230 (address)oopDesc::load_decode_heap_oop(discovered_addr) : NULL));
231 }
232 }
233 #endif
234
235 template <class T> void static adjust_object_specialized(oop obj) {
236 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
237 MarkSweep::adjust_pointer(referent_addr);
238 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
239 MarkSweep::adjust_pointer(next_addr);
240 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
241 MarkSweep::adjust_pointer(discovered_addr);
242 debug_only(trace_reference_gc("InstanceRefKlass::oop_ms_adjust_pointers", obj,
243 referent_addr, next_addr, discovered_addr);)
244 }
245
246 int InstanceRefKlass::oop_ms_adjust_pointers(oop obj) {
247 int size = size_helper();
248 InstanceKlass::oop_ms_adjust_pointers(obj);
249
250 if (UseCompressedOops) {
251 adjust_object_specialized<narrowOop>(obj);
252 } else {
253 adjust_object_specialized<oop>(obj);
254 }
255 return size;
256 }
257
258 int ObjArrayKlass::oop_ms_adjust_pointers(oop obj) {
259 assert(obj->is_objArray(), "obj must be obj array");
260 objArrayOop a = objArrayOop(obj);
261 // Get size before changing pointers.
262 // Don't call size() or oop_size() since that is a virtual call.
263 int size = a->object_size();
264 oop_oop_iterate_elements<true>(a, &MarkSweep::adjust_pointer_closure);
265 return size;
266 }
267
268 int TypeArrayKlass::oop_ms_adjust_pointers(oop obj) {
269 assert(obj->is_typeArray(), "must be a type array");
270 typeArrayOop t = typeArrayOop(obj);
271 // Performance tweak: We skip iterating over the klass pointer since we
272 // know that Universe::TypeArrayKlass never moves.
273 return t->object_size();
274 }
275
276 // Generate MS specialized oop_oop_iterate functions.
277 SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_MS(ALL_KLASS_OOP_OOP_ITERATE_DEFN)