Fri, 25 Sep 2009 12:17:06 -0700
Merge
1 /*
2 * Copyright 1997-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 #include "incls/_precompiled.incl"
26 #include "incls/_markSweep.cpp.incl"
28 GrowableArray<oop>* MarkSweep::_marking_stack = NULL;
29 GrowableArray<Klass*>* MarkSweep::_revisit_klass_stack = NULL;
30 GrowableArray<DataLayout*>* MarkSweep::_revisit_mdo_stack = NULL;
32 GrowableArray<oop>* MarkSweep::_preserved_oop_stack = NULL;
33 GrowableArray<markOop>* MarkSweep::_preserved_mark_stack= NULL;
34 size_t MarkSweep::_preserved_count = 0;
35 size_t MarkSweep::_preserved_count_max = 0;
36 PreservedMark* MarkSweep::_preserved_marks = NULL;
37 ReferenceProcessor* MarkSweep::_ref_processor = NULL;
39 #ifdef VALIDATE_MARK_SWEEP
40 GrowableArray<void*>* MarkSweep::_root_refs_stack = NULL;
41 GrowableArray<oop> * MarkSweep::_live_oops = NULL;
42 GrowableArray<oop> * MarkSweep::_live_oops_moved_to = NULL;
43 GrowableArray<size_t>* MarkSweep::_live_oops_size = NULL;
44 size_t MarkSweep::_live_oops_index = 0;
45 size_t MarkSweep::_live_oops_index_at_perm = 0;
46 GrowableArray<void*>* MarkSweep::_other_refs_stack = NULL;
47 GrowableArray<void*>* MarkSweep::_adjusted_pointers = NULL;
48 bool MarkSweep::_pointer_tracking = false;
49 bool MarkSweep::_root_tracking = true;
51 GrowableArray<HeapWord*>* MarkSweep::_cur_gc_live_oops = NULL;
52 GrowableArray<HeapWord*>* MarkSweep::_cur_gc_live_oops_moved_to = NULL;
53 GrowableArray<size_t> * MarkSweep::_cur_gc_live_oops_size = NULL;
54 GrowableArray<HeapWord*>* MarkSweep::_last_gc_live_oops = NULL;
55 GrowableArray<HeapWord*>* MarkSweep::_last_gc_live_oops_moved_to = NULL;
56 GrowableArray<size_t> * MarkSweep::_last_gc_live_oops_size = NULL;
57 #endif
59 void MarkSweep::revisit_weak_klass_link(Klass* k) {
60 _revisit_klass_stack->push(k);
61 }
63 void MarkSweep::follow_weak_klass_links() {
64 // All klasses on the revisit stack are marked at this point.
65 // Update and follow all subklass, sibling and implementor links.
66 if (PrintRevisitStats) {
67 gclog_or_tty->print_cr("#classes in system dictionary = %d", SystemDictionary::number_of_classes());
68 gclog_or_tty->print_cr("Revisit klass stack length = %d", _revisit_klass_stack->length());
69 }
70 for (int i = 0; i < _revisit_klass_stack->length(); i++) {
71 _revisit_klass_stack->at(i)->follow_weak_klass_links(&is_alive,&keep_alive);
72 }
73 follow_stack();
74 }
76 void MarkSweep::revisit_mdo(DataLayout* p) {
77 _revisit_mdo_stack->push(p);
78 }
80 void MarkSweep::follow_mdo_weak_refs() {
81 // All strongly reachable oops have been marked at this point;
82 // we can visit and clear any weak references from MDO's which
83 // we memoized during the strong marking phase.
84 assert(_marking_stack->is_empty(), "Marking stack should be empty");
85 if (PrintRevisitStats) {
86 gclog_or_tty->print_cr("#classes in system dictionary = %d", SystemDictionary::number_of_classes());
87 gclog_or_tty->print_cr("Revisit MDO stack length = %d", _revisit_mdo_stack->length());
88 }
89 for (int i = 0; i < _revisit_mdo_stack->length(); i++) {
90 _revisit_mdo_stack->at(i)->follow_weak_refs(&is_alive);
91 }
92 follow_stack();
93 }
95 MarkSweep::FollowRootClosure MarkSweep::follow_root_closure;
97 void MarkSweep::FollowRootClosure::do_oop(oop* p) { follow_root(p); }
98 void MarkSweep::FollowRootClosure::do_oop(narrowOop* p) { follow_root(p); }
100 MarkSweep::MarkAndPushClosure MarkSweep::mark_and_push_closure;
102 void MarkSweep::MarkAndPushClosure::do_oop(oop* p) { mark_and_push(p); }
103 void MarkSweep::MarkAndPushClosure::do_oop(narrowOop* p) { mark_and_push(p); }
105 void MarkSweep::follow_stack() {
106 while (!_marking_stack->is_empty()) {
107 oop obj = _marking_stack->pop();
108 assert (obj->is_gc_marked(), "p must be marked");
109 obj->follow_contents();
110 }
111 }
113 MarkSweep::FollowStackClosure MarkSweep::follow_stack_closure;
115 void MarkSweep::FollowStackClosure::do_void() { follow_stack(); }
117 // We preserve the mark which should be replaced at the end and the location that it
118 // will go. Note that the object that this markOop belongs to isn't currently at that
119 // address but it will be after phase4
120 void MarkSweep::preserve_mark(oop obj, markOop mark) {
121 // we try to store preserved marks in the to space of the new generation since this
122 // is storage which should be available. Most of the time this should be sufficient
123 // space for the marks we need to preserve but if it isn't we fall back in using
124 // GrowableArrays to keep track of the overflow.
125 if (_preserved_count < _preserved_count_max) {
126 _preserved_marks[_preserved_count++].init(obj, mark);
127 } else {
128 if (_preserved_mark_stack == NULL) {
129 _preserved_mark_stack = new (ResourceObj::C_HEAP) GrowableArray<markOop>(40, true);
130 _preserved_oop_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true);
131 }
132 _preserved_mark_stack->push(mark);
133 _preserved_oop_stack->push(obj);
134 }
135 }
137 MarkSweep::AdjustPointerClosure MarkSweep::adjust_root_pointer_closure(true);
138 MarkSweep::AdjustPointerClosure MarkSweep::adjust_pointer_closure(false);
140 void MarkSweep::AdjustPointerClosure::do_oop(oop* p) { adjust_pointer(p, _is_root); }
141 void MarkSweep::AdjustPointerClosure::do_oop(narrowOop* p) { adjust_pointer(p, _is_root); }
143 void MarkSweep::adjust_marks() {
144 assert(_preserved_oop_stack == NULL ||
145 _preserved_oop_stack->length() == _preserved_mark_stack->length(),
146 "inconsistent preserved oop stacks");
148 // adjust the oops we saved earlier
149 for (size_t i = 0; i < _preserved_count; i++) {
150 _preserved_marks[i].adjust_pointer();
151 }
153 // deal with the overflow stack
154 if (_preserved_oop_stack) {
155 for (int i = 0; i < _preserved_oop_stack->length(); i++) {
156 oop* p = _preserved_oop_stack->adr_at(i);
157 adjust_pointer(p);
158 }
159 }
160 }
162 void MarkSweep::restore_marks() {
163 assert(_preserved_oop_stack == NULL ||
164 _preserved_oop_stack->length() == _preserved_mark_stack->length(),
165 "inconsistent preserved oop stacks");
166 if (PrintGC && Verbose) {
167 gclog_or_tty->print_cr("Restoring %d marks", _preserved_count +
168 (_preserved_oop_stack ? _preserved_oop_stack->length() : 0));
169 }
171 // restore the marks we saved earlier
172 for (size_t i = 0; i < _preserved_count; i++) {
173 _preserved_marks[i].restore();
174 }
176 // deal with the overflow
177 if (_preserved_oop_stack) {
178 for (int i = 0; i < _preserved_oop_stack->length(); i++) {
179 oop obj = _preserved_oop_stack->at(i);
180 markOop mark = _preserved_mark_stack->at(i);
181 obj->set_mark(mark);
182 }
183 }
184 }
186 #ifdef VALIDATE_MARK_SWEEP
188 void MarkSweep::track_adjusted_pointer(void* p, bool isroot) {
189 if (!ValidateMarkSweep)
190 return;
192 if (!isroot) {
193 if (_pointer_tracking) {
194 guarantee(_adjusted_pointers->contains(p), "should have seen this pointer");
195 _adjusted_pointers->remove(p);
196 }
197 } else {
198 ptrdiff_t index = _root_refs_stack->find(p);
199 if (index != -1) {
200 int l = _root_refs_stack->length();
201 if (l > 0 && l - 1 != index) {
202 void* last = _root_refs_stack->pop();
203 assert(last != p, "should be different");
204 _root_refs_stack->at_put(index, last);
205 } else {
206 _root_refs_stack->remove(p);
207 }
208 }
209 }
210 }
212 void MarkSweep::check_adjust_pointer(void* p) {
213 _adjusted_pointers->push(p);
214 }
216 class AdjusterTracker: public OopClosure {
217 public:
218 AdjusterTracker() {}
219 void do_oop(oop* o) { MarkSweep::check_adjust_pointer(o); }
220 void do_oop(narrowOop* o) { MarkSweep::check_adjust_pointer(o); }
221 };
223 void MarkSweep::track_interior_pointers(oop obj) {
224 if (ValidateMarkSweep) {
225 _adjusted_pointers->clear();
226 _pointer_tracking = true;
228 AdjusterTracker checker;
229 obj->oop_iterate(&checker);
230 }
231 }
233 void MarkSweep::check_interior_pointers() {
234 if (ValidateMarkSweep) {
235 _pointer_tracking = false;
236 guarantee(_adjusted_pointers->length() == 0, "should have processed the same pointers");
237 }
238 }
240 void MarkSweep::reset_live_oop_tracking(bool at_perm) {
241 if (ValidateMarkSweep) {
242 guarantee((size_t)_live_oops->length() == _live_oops_index, "should be at end of live oops");
243 _live_oops_index = at_perm ? _live_oops_index_at_perm : 0;
244 }
245 }
247 void MarkSweep::register_live_oop(oop p, size_t size) {
248 if (ValidateMarkSweep) {
249 _live_oops->push(p);
250 _live_oops_size->push(size);
251 _live_oops_index++;
252 }
253 }
255 void MarkSweep::validate_live_oop(oop p, size_t size) {
256 if (ValidateMarkSweep) {
257 oop obj = _live_oops->at((int)_live_oops_index);
258 guarantee(obj == p, "should be the same object");
259 guarantee(_live_oops_size->at((int)_live_oops_index) == size, "should be the same size");
260 _live_oops_index++;
261 }
262 }
264 void MarkSweep::live_oop_moved_to(HeapWord* q, size_t size,
265 HeapWord* compaction_top) {
266 assert(oop(q)->forwardee() == NULL || oop(q)->forwardee() == oop(compaction_top),
267 "should be moved to forwarded location");
268 if (ValidateMarkSweep) {
269 MarkSweep::validate_live_oop(oop(q), size);
270 _live_oops_moved_to->push(oop(compaction_top));
271 }
272 if (RecordMarkSweepCompaction) {
273 _cur_gc_live_oops->push(q);
274 _cur_gc_live_oops_moved_to->push(compaction_top);
275 _cur_gc_live_oops_size->push(size);
276 }
277 }
279 void MarkSweep::compaction_complete() {
280 if (RecordMarkSweepCompaction) {
281 GrowableArray<HeapWord*>* _tmp_live_oops = _cur_gc_live_oops;
282 GrowableArray<HeapWord*>* _tmp_live_oops_moved_to = _cur_gc_live_oops_moved_to;
283 GrowableArray<size_t> * _tmp_live_oops_size = _cur_gc_live_oops_size;
285 _cur_gc_live_oops = _last_gc_live_oops;
286 _cur_gc_live_oops_moved_to = _last_gc_live_oops_moved_to;
287 _cur_gc_live_oops_size = _last_gc_live_oops_size;
288 _last_gc_live_oops = _tmp_live_oops;
289 _last_gc_live_oops_moved_to = _tmp_live_oops_moved_to;
290 _last_gc_live_oops_size = _tmp_live_oops_size;
291 }
292 }
294 void MarkSweep::print_new_location_of_heap_address(HeapWord* q) {
295 if (!RecordMarkSweepCompaction) {
296 tty->print_cr("Requires RecordMarkSweepCompaction to be enabled");
297 return;
298 }
300 if (_last_gc_live_oops == NULL) {
301 tty->print_cr("No compaction information gathered yet");
302 return;
303 }
305 for (int i = 0; i < _last_gc_live_oops->length(); i++) {
306 HeapWord* old_oop = _last_gc_live_oops->at(i);
307 size_t sz = _last_gc_live_oops_size->at(i);
308 if (old_oop <= q && q < (old_oop + sz)) {
309 HeapWord* new_oop = _last_gc_live_oops_moved_to->at(i);
310 size_t offset = (q - old_oop);
311 tty->print_cr("Address " PTR_FORMAT, q);
312 tty->print_cr(" Was in oop " PTR_FORMAT ", size " SIZE_FORMAT ", at offset " SIZE_FORMAT, old_oop, sz, offset);
313 tty->print_cr(" Now in oop " PTR_FORMAT ", actual address " PTR_FORMAT, new_oop, new_oop + offset);
314 return;
315 }
316 }
318 tty->print_cr("Address " PTR_FORMAT " not found in live oop information from last GC", q);
319 }
320 #endif //VALIDATE_MARK_SWEEP
322 MarkSweep::IsAliveClosure MarkSweep::is_alive;
324 void MarkSweep::IsAliveClosure::do_object(oop p) { ShouldNotReachHere(); }
325 bool MarkSweep::IsAliveClosure::do_object_b(oop p) { return p->is_gc_marked(); }
327 MarkSweep::KeepAliveClosure MarkSweep::keep_alive;
329 void MarkSweep::KeepAliveClosure::do_oop(oop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
330 void MarkSweep::KeepAliveClosure::do_oop(narrowOop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
332 void marksweep_init() { /* empty */ }
334 #ifndef PRODUCT
336 void MarkSweep::trace(const char* msg) {
337 if (TraceMarkSweep)
338 gclog_or_tty->print("%s", msg);
339 }
341 #endif