Mercurial > hg > truffle
annotate src/share/vm/memory/dump.cpp @ 2038:74ee0db180fa
6807801: CMS: could save/restore fewer header words during scavenge
Summary: Age bits need not enter the mark-word preservation calculus; also affected, in addition to CMS, per CR synopsis above, were ParNew (but not DefNew), ParallelScavenge and G1, albeit to a lesser degree than CMS.
Reviewed-by: tonyp, johnc
author | ysr |
---|---|
date | Fri, 17 Dec 2010 23:41:31 -0800 |
parents | 828eafbd85cc |
children | 3582bf76420e |
rev | line source |
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0 | 1 /* |
1972 | 2 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. |
0 | 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 * | |
1552
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #include "precompiled.hpp" |
26 #include "classfile/javaClasses.hpp" | |
27 #include "classfile/loaderConstraints.hpp" | |
28 #include "classfile/symbolTable.hpp" | |
29 #include "classfile/systemDictionary.hpp" | |
30 #include "gc_implementation/shared/spaceDecorator.hpp" | |
31 #include "memory/classify.hpp" | |
32 #include "memory/filemap.hpp" | |
33 #include "memory/oopFactory.hpp" | |
34 #include "memory/resourceArea.hpp" | |
35 #include "oops/methodDataOop.hpp" | |
36 #include "oops/oop.inline.hpp" | |
37 #include "runtime/javaCalls.hpp" | |
38 #include "runtime/signature.hpp" | |
39 #include "runtime/vmThread.hpp" | |
40 #include "runtime/vm_operations.hpp" | |
41 #include "utilities/copy.hpp" | |
0 | 42 |
43 | |
44 // Closure to set up the fingerprint field for all methods. | |
45 | |
46 class FingerprintMethodsClosure: public ObjectClosure { | |
47 public: | |
48 void do_object(oop obj) { | |
49 if (obj->is_method()) { | |
50 methodOop mobj = (methodOop)obj; | |
51 ResourceMark rm; | |
52 (new Fingerprinter(mobj))->fingerprint(); | |
53 } | |
54 } | |
55 }; | |
56 | |
57 | |
58 | |
59 // Closure to set the hash value (String.hash field) in all of the | |
60 // String objects in the heap. Setting the hash value is not required. | |
61 // However, setting the value in advance prevents the value from being | |
62 // written later, increasing the likelihood that the shared page contain | |
63 // the hash can be shared. | |
64 // | |
65 // NOTE THAT the algorithm in StringTable::hash_string() MUST MATCH the | |
66 // algorithm in java.lang.String.hashCode(). | |
67 | |
68 class StringHashCodeClosure: public OopClosure { | |
69 private: | |
70 Thread* THREAD; | |
71 int hash_offset; | |
72 public: | |
73 StringHashCodeClosure(Thread* t) { | |
74 THREAD = t; | |
75 hash_offset = java_lang_String::hash_offset_in_bytes(); | |
76 } | |
77 | |
113
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78 void do_oop(oop* p) { |
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79 if (p != NULL) { |
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80 oop obj = *p; |
1142 | 81 if (obj->klass() == SystemDictionary::String_klass()) { |
0 | 82 |
83 int hash; | |
84 typeArrayOop value = java_lang_String::value(obj); | |
85 int length = java_lang_String::length(obj); | |
86 if (length == 0) { | |
87 hash = 0; | |
88 } else { | |
89 int offset = java_lang_String::offset(obj); | |
90 jchar* s = value->char_at_addr(offset); | |
91 hash = StringTable::hash_string(s, length); | |
92 } | |
93 obj->int_field_put(hash_offset, hash); | |
94 } | |
95 } | |
96 } | |
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97 void do_oop(narrowOop* p) { ShouldNotReachHere(); } |
0 | 98 }; |
99 | |
100 | |
101 // Remove data from objects which should not appear in the shared file | |
102 // (as it pertains only to the current JVM). | |
103 | |
104 class RemoveUnshareableInfoClosure : public ObjectClosure { | |
105 public: | |
106 void do_object(oop obj) { | |
107 // Zap data from the objects which is pertains only to this JVM. We | |
108 // want that data recreated in new JVMs when the shared file is used. | |
109 if (obj->is_method()) { | |
110 ((methodOop)obj)->remove_unshareable_info(); | |
111 } | |
112 else if (obj->is_klass()) { | |
113 Klass::cast((klassOop)obj)->remove_unshareable_info(); | |
114 } | |
115 | |
116 // Don't save compiler related special oops (shouldn't be any yet). | |
117 if (obj->is_methodData() || obj->is_compiledICHolder()) { | |
118 ShouldNotReachHere(); | |
119 } | |
120 } | |
121 }; | |
122 | |
123 | |
124 static bool mark_object(oop obj) { | |
125 if (obj != NULL && | |
126 !obj->is_shared() && | |
127 !obj->is_forwarded() && | |
128 !obj->is_gc_marked()) { | |
129 obj->set_mark(markOopDesc::prototype()->set_marked()); | |
130 return true; | |
131 } | |
132 | |
133 return false; | |
134 } | |
135 | |
136 // Closure: mark objects closure. | |
137 | |
138 class MarkObjectsOopClosure : public OopClosure { | |
139 public: | |
113
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140 void do_oop(oop* p) { mark_object(*p); } |
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141 void do_oop(narrowOop* p) { ShouldNotReachHere(); } |
0 | 142 }; |
143 | |
144 | |
145 class MarkObjectsSkippingKlassesOopClosure : public OopClosure { | |
146 public: | |
147 void do_oop(oop* pobj) { | |
148 oop obj = *pobj; | |
149 if (obj != NULL && | |
150 !obj->is_klass()) { | |
151 mark_object(obj); | |
152 } | |
153 } | |
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154 void do_oop(narrowOop* pobj) { ShouldNotReachHere(); } |
0 | 155 }; |
156 | |
157 | |
158 static void mark_object_recursive_skipping_klasses(oop obj) { | |
159 mark_object(obj); | |
160 if (obj != NULL) { | |
161 MarkObjectsSkippingKlassesOopClosure mark_all; | |
162 obj->oop_iterate(&mark_all); | |
163 } | |
164 } | |
165 | |
166 | |
167 // Closure: mark common read-only objects, excluding symbols | |
168 | |
169 class MarkCommonReadOnly : public ObjectClosure { | |
170 private: | |
171 MarkObjectsOopClosure mark_all; | |
172 public: | |
173 void do_object(oop obj) { | |
174 | |
175 // Mark all constMethod objects. | |
176 | |
177 if (obj->is_constMethod()) { | |
178 mark_object(obj); | |
179 mark_object(constMethodOop(obj)->stackmap_data()); | |
180 // Exception tables are needed by ci code during compilation. | |
181 mark_object(constMethodOop(obj)->exception_table()); | |
182 } | |
183 | |
184 // Mark objects referenced by klass objects which are read-only. | |
185 | |
186 else if (obj->is_klass()) { | |
187 Klass* k = Klass::cast((klassOop)obj); | |
188 mark_object(k->secondary_supers()); | |
189 | |
190 // The METHODS() OBJARRAYS CANNOT BE MADE READ-ONLY, even though | |
191 // it is never modified. Otherwise, they will be pre-marked; the | |
192 // GC marking phase will skip them; and by skipping them will fail | |
193 // to mark the methods objects referenced by the array. | |
194 | |
195 if (obj->blueprint()->oop_is_instanceKlass()) { | |
196 instanceKlass* ik = instanceKlass::cast((klassOop)obj); | |
197 mark_object(ik->method_ordering()); | |
198 mark_object(ik->local_interfaces()); | |
199 mark_object(ik->transitive_interfaces()); | |
200 mark_object(ik->fields()); | |
201 | |
202 mark_object(ik->class_annotations()); | |
203 | |
204 mark_object_recursive_skipping_klasses(ik->fields_annotations()); | |
205 mark_object_recursive_skipping_klasses(ik->methods_annotations()); | |
206 mark_object_recursive_skipping_klasses(ik->methods_parameter_annotations()); | |
207 mark_object_recursive_skipping_klasses(ik->methods_default_annotations()); | |
208 | |
209 typeArrayOop inner_classes = ik->inner_classes(); | |
210 if (inner_classes != NULL) { | |
211 mark_object(inner_classes); | |
212 } | |
213 } | |
214 } | |
215 } | |
216 }; | |
217 | |
218 | |
219 // Closure: mark common symbols | |
220 | |
221 class MarkCommonSymbols : public ObjectClosure { | |
222 private: | |
223 MarkObjectsOopClosure mark_all; | |
224 public: | |
225 void do_object(oop obj) { | |
226 | |
227 // Mark symbols refered to by method objects. | |
228 | |
229 if (obj->is_method()) { | |
230 methodOop m = methodOop(obj); | |
231 mark_object(m->name()); | |
232 mark_object(m->signature()); | |
233 } | |
234 | |
235 // Mark symbols referenced by klass objects which are read-only. | |
236 | |
237 else if (obj->is_klass()) { | |
238 | |
239 if (obj->blueprint()->oop_is_instanceKlass()) { | |
240 instanceKlass* ik = instanceKlass::cast((klassOop)obj); | |
241 mark_object(ik->name()); | |
242 mark_object(ik->generic_signature()); | |
243 mark_object(ik->source_file_name()); | |
244 mark_object(ik->source_debug_extension()); | |
245 | |
246 typeArrayOop inner_classes = ik->inner_classes(); | |
247 if (inner_classes != NULL) { | |
248 int length = inner_classes->length(); | |
249 for (int i = 0; | |
250 i < length; | |
251 i += instanceKlass::inner_class_next_offset) { | |
252 int ioff = i + instanceKlass::inner_class_inner_name_offset; | |
253 int index = inner_classes->ushort_at(ioff); | |
254 if (index != 0) { | |
255 mark_object(ik->constants()->symbol_at(index)); | |
256 } | |
257 } | |
258 } | |
259 ik->field_names_and_sigs_iterate(&mark_all); | |
260 } | |
261 } | |
262 | |
263 // Mark symbols referenced by other constantpool entries. | |
264 | |
265 if (obj->is_constantPool()) { | |
266 constantPoolOop(obj)->shared_symbols_iterate(&mark_all); | |
267 } | |
268 } | |
269 }; | |
270 | |
271 | |
272 // Closure: mark char arrays used by strings | |
273 | |
274 class MarkStringValues : public ObjectClosure { | |
275 private: | |
276 MarkObjectsOopClosure mark_all; | |
277 public: | |
278 void do_object(oop obj) { | |
279 | |
280 // Character arrays referenced by String objects are read-only. | |
281 | |
282 if (java_lang_String::is_instance(obj)) { | |
283 mark_object(java_lang_String::value(obj)); | |
284 } | |
285 } | |
286 }; | |
287 | |
288 | |
289 #ifdef DEBUG | |
290 // Closure: Check for objects left in the heap which have not been moved. | |
291 | |
292 class CheckRemainingObjects : public ObjectClosure { | |
293 private: | |
294 int count; | |
295 | |
296 public: | |
297 CheckRemainingObjects() { | |
298 count = 0; | |
299 } | |
300 | |
301 void do_object(oop obj) { | |
302 if (!obj->is_shared() && | |
303 !obj->is_forwarded()) { | |
304 ++count; | |
305 if (Verbose) { | |
306 tty->print("Unreferenced object: "); | |
307 obj->print_on(tty); | |
308 } | |
309 } | |
310 } | |
311 | |
312 void status() { | |
313 tty->print_cr("%d objects no longer referenced, not shared.", count); | |
314 } | |
315 }; | |
316 #endif | |
317 | |
318 | |
319 // Closure: Mark remaining objects read-write, except Strings. | |
320 | |
321 class MarkReadWriteObjects : public ObjectClosure { | |
322 private: | |
323 MarkObjectsOopClosure mark_objects; | |
324 public: | |
325 void do_object(oop obj) { | |
326 | |
327 // The METHODS() OBJARRAYS CANNOT BE MADE READ-ONLY, even though | |
328 // it is never modified. Otherwise, they will be pre-marked; the | |
329 // GC marking phase will skip them; and by skipping them will fail | |
330 // to mark the methods objects referenced by the array. | |
331 | |
332 if (obj->is_klass()) { | |
333 mark_object(obj); | |
334 Klass* k = klassOop(obj)->klass_part(); | |
335 mark_object(k->java_mirror()); | |
336 if (obj->blueprint()->oop_is_instanceKlass()) { | |
337 instanceKlass* ik = (instanceKlass*)k; | |
338 mark_object(ik->methods()); | |
339 mark_object(ik->constants()); | |
340 } | |
341 if (obj->blueprint()->oop_is_javaArray()) { | |
342 arrayKlass* ak = (arrayKlass*)k; | |
343 mark_object(ak->component_mirror()); | |
344 } | |
345 return; | |
346 } | |
347 | |
348 // Mark constantPool tags and the constantPoolCache. | |
349 | |
350 else if (obj->is_constantPool()) { | |
351 constantPoolOop pool = constantPoolOop(obj); | |
352 mark_object(pool->cache()); | |
353 pool->shared_tags_iterate(&mark_objects); | |
354 return; | |
355 } | |
356 | |
357 // Mark all method objects. | |
358 | |
359 if (obj->is_method()) { | |
360 mark_object(obj); | |
361 } | |
362 } | |
363 }; | |
364 | |
365 | |
366 // Closure: Mark String objects read-write. | |
367 | |
368 class MarkStringObjects : public ObjectClosure { | |
369 private: | |
370 MarkObjectsOopClosure mark_objects; | |
371 public: | |
372 void do_object(oop obj) { | |
373 | |
374 // Mark String objects referenced by constant pool entries. | |
375 | |
376 if (obj->is_constantPool()) { | |
377 constantPoolOop pool = constantPoolOop(obj); | |
378 pool->shared_strings_iterate(&mark_objects); | |
379 return; | |
380 } | |
381 } | |
382 }; | |
383 | |
384 | |
385 // Move objects matching specified type (ie. lock_bits) to the specified | |
386 // space. | |
387 | |
388 class MoveMarkedObjects : public ObjectClosure { | |
389 private: | |
390 OffsetTableContigSpace* _space; | |
391 bool _read_only; | |
392 | |
393 public: | |
394 MoveMarkedObjects(OffsetTableContigSpace* space, bool read_only) { | |
395 _space = space; | |
396 _read_only = read_only; | |
397 } | |
398 | |
399 void do_object(oop obj) { | |
400 if (obj->is_shared()) { | |
401 return; | |
402 } | |
403 if (obj->is_gc_marked() && obj->forwardee() == NULL) { | |
404 int s = obj->size(); | |
405 oop sh_obj = (oop)_space->allocate(s); | |
406 if (sh_obj == NULL) { | |
407 if (_read_only) { | |
408 warning("\nThe permanent generation read only space is not large " | |
409 "enough to \npreload requested classes. Use " | |
410 "-XX:SharedReadOnlySize= to increase \nthe initial " | |
411 "size of the read only space.\n"); | |
412 } else { | |
413 warning("\nThe permanent generation read write space is not large " | |
414 "enough to \npreload requested classes. Use " | |
415 "-XX:SharedReadWriteSize= to increase \nthe initial " | |
416 "size of the read write space.\n"); | |
417 } | |
418 exit(2); | |
419 } | |
420 if (PrintSharedSpaces && Verbose && WizardMode) { | |
421 tty->print_cr("\nMoveMarkedObjects: " PTR_FORMAT " -> " PTR_FORMAT " %s", obj, sh_obj, | |
422 (_read_only ? "ro" : "rw")); | |
423 } | |
424 Copy::aligned_disjoint_words((HeapWord*)obj, (HeapWord*)sh_obj, s); | |
425 obj->forward_to(sh_obj); | |
426 if (_read_only) { | |
427 // Readonly objects: set hash value to self pointer and make gc_marked. | |
428 sh_obj->forward_to(sh_obj); | |
429 } else { | |
430 sh_obj->init_mark(); | |
431 } | |
432 } | |
433 } | |
434 }; | |
435 | |
436 static void mark_and_move(oop obj, MoveMarkedObjects* move) { | |
437 if (mark_object(obj)) move->do_object(obj); | |
438 } | |
439 | |
440 enum order_policy { | |
441 OP_favor_startup = 0, | |
442 OP_balanced = 1, | |
443 OP_favor_runtime = 2 | |
444 }; | |
445 | |
446 static void mark_and_move_for_policy(order_policy policy, oop obj, MoveMarkedObjects* move) { | |
447 if (SharedOptimizeColdStartPolicy >= policy) mark_and_move(obj, move); | |
448 } | |
449 | |
450 class MarkAndMoveOrderedReadOnly : public ObjectClosure { | |
451 private: | |
452 MoveMarkedObjects *_move_ro; | |
453 | |
454 public: | |
455 MarkAndMoveOrderedReadOnly(MoveMarkedObjects *move_ro) : _move_ro(move_ro) {} | |
456 | |
457 void do_object(oop obj) { | |
458 if (obj->is_klass() && obj->blueprint()->oop_is_instanceKlass()) { | |
459 instanceKlass* ik = instanceKlass::cast((klassOop)obj); | |
460 int i; | |
461 | |
462 mark_and_move_for_policy(OP_favor_startup, ik->name(), _move_ro); | |
463 | |
464 if (ik->super() != NULL) { | |
465 do_object(ik->super()); | |
466 } | |
467 | |
468 objArrayOop interfaces = ik->local_interfaces(); | |
469 mark_and_move_for_policy(OP_favor_startup, interfaces, _move_ro); | |
470 for(i = 0; i < interfaces->length(); i++) { | |
471 klassOop k = klassOop(interfaces->obj_at(i)); | |
472 mark_and_move_for_policy(OP_favor_startup, k->klass_part()->name(), _move_ro); | |
473 do_object(k); | |
474 } | |
475 | |
476 objArrayOop methods = ik->methods(); | |
477 for(i = 0; i < methods->length(); i++) { | |
478 methodOop m = methodOop(methods->obj_at(i)); | |
479 mark_and_move_for_policy(OP_favor_startup, m->constMethod(), _move_ro); | |
480 mark_and_move_for_policy(OP_favor_runtime, m->constMethod()->exception_table(), _move_ro); | |
481 mark_and_move_for_policy(OP_favor_runtime, m->constMethod()->stackmap_data(), _move_ro); | |
482 | |
483 // We don't move the name symbolOop here because it may invalidate | |
484 // method ordering, which is dependent on the address of the name | |
485 // symbolOop. It will get promoted later with the other symbols. | |
486 // Method name is rarely accessed during classloading anyway. | |
487 // mark_and_move_for_policy(OP_balanced, m->name(), _move_ro); | |
488 | |
489 mark_and_move_for_policy(OP_favor_startup, m->signature(), _move_ro); | |
490 } | |
491 | |
492 mark_and_move_for_policy(OP_favor_startup, ik->transitive_interfaces(), _move_ro); | |
493 mark_and_move_for_policy(OP_favor_startup, ik->fields(), _move_ro); | |
494 | |
495 mark_and_move_for_policy(OP_favor_runtime, ik->secondary_supers(), _move_ro); | |
496 mark_and_move_for_policy(OP_favor_runtime, ik->method_ordering(), _move_ro); | |
497 mark_and_move_for_policy(OP_favor_runtime, ik->class_annotations(), _move_ro); | |
498 mark_and_move_for_policy(OP_favor_runtime, ik->fields_annotations(), _move_ro); | |
499 mark_and_move_for_policy(OP_favor_runtime, ik->methods_annotations(), _move_ro); | |
500 mark_and_move_for_policy(OP_favor_runtime, ik->methods_parameter_annotations(), _move_ro); | |
501 mark_and_move_for_policy(OP_favor_runtime, ik->methods_default_annotations(), _move_ro); | |
502 mark_and_move_for_policy(OP_favor_runtime, ik->inner_classes(), _move_ro); | |
503 mark_and_move_for_policy(OP_favor_runtime, ik->secondary_supers(), _move_ro); | |
504 } | |
505 } | |
506 }; | |
507 | |
508 class MarkAndMoveOrderedReadWrite: public ObjectClosure { | |
509 private: | |
510 MoveMarkedObjects *_move_rw; | |
511 | |
512 public: | |
513 MarkAndMoveOrderedReadWrite(MoveMarkedObjects *move_rw) : _move_rw(move_rw) {} | |
514 | |
515 void do_object(oop obj) { | |
516 if (obj->is_klass() && obj->blueprint()->oop_is_instanceKlass()) { | |
517 instanceKlass* ik = instanceKlass::cast((klassOop)obj); | |
518 int i; | |
519 | |
520 mark_and_move_for_policy(OP_favor_startup, ik->as_klassOop(), _move_rw); | |
521 | |
522 if (ik->super() != NULL) { | |
523 do_object(ik->super()); | |
524 } | |
525 | |
526 objArrayOop interfaces = ik->local_interfaces(); | |
527 for(i = 0; i < interfaces->length(); i++) { | |
528 klassOop k = klassOop(interfaces->obj_at(i)); | |
529 mark_and_move_for_policy(OP_favor_startup, k, _move_rw); | |
530 do_object(k); | |
531 } | |
532 | |
533 objArrayOop methods = ik->methods(); | |
534 mark_and_move_for_policy(OP_favor_startup, methods, _move_rw); | |
535 for(i = 0; i < methods->length(); i++) { | |
536 methodOop m = methodOop(methods->obj_at(i)); | |
537 mark_and_move_for_policy(OP_favor_startup, m, _move_rw); | |
538 mark_and_move_for_policy(OP_favor_startup, ik->constants(), _move_rw); // idempotent | |
539 mark_and_move_for_policy(OP_balanced, ik->constants()->cache(), _move_rw); // idempotent | |
540 mark_and_move_for_policy(OP_balanced, ik->constants()->tags(), _move_rw); // idempotent | |
541 } | |
542 | |
543 mark_and_move_for_policy(OP_favor_startup, ik->as_klassOop()->klass(), _move_rw); | |
544 mark_and_move_for_policy(OP_favor_startup, ik->constants()->klass(), _move_rw); | |
545 | |
546 // Although Java mirrors are marked in MarkReadWriteObjects, | |
547 // apparently they were never moved into shared spaces since | |
548 // MoveMarkedObjects skips marked instance oops. This may | |
549 // be a bug in the original implementation or simply the vestige | |
550 // of an abandoned experiment. Nevertheless we leave a hint | |
551 // here in case this capability is ever correctly implemented. | |
552 // | |
553 // mark_and_move_for_policy(OP_favor_runtime, ik->java_mirror(), _move_rw); | |
554 } | |
555 } | |
556 | |
557 }; | |
558 | |
559 // Adjust references in oops to refer to shared spaces. | |
560 | |
561 class ResolveForwardingClosure: public OopClosure { | |
562 public: | |
563 void do_oop(oop* p) { | |
564 oop obj = *p; | |
565 if (!obj->is_shared()) { | |
566 if (obj != NULL) { | |
567 oop f = obj->forwardee(); | |
568 guarantee(f->is_shared(), "Oop doesn't refer to shared space."); | |
569 *p = f; | |
570 } | |
571 } | |
572 } | |
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573 void do_oop(narrowOop* pobj) { ShouldNotReachHere(); } |
0 | 574 }; |
575 | |
576 | |
577 void sort_methods(instanceKlass* ik, TRAPS) { | |
578 klassOop super = ik->super(); | |
579 if (super != NULL) { | |
580 sort_methods(instanceKlass::cast(super), THREAD); | |
581 } | |
582 | |
583 // The methods array must be ordered by symbolOop address. (See | |
584 // classFileParser.cpp where methods in a class are originally | |
585 // sorted.) Since objects have just be reordered, this must be | |
586 // corrected. | |
587 methodOopDesc::sort_methods(ik->methods(), | |
588 ik->methods_annotations(), | |
589 ik->methods_parameter_annotations(), | |
590 ik->methods_default_annotations(), | |
591 true /* idempotent, slow */); | |
592 | |
593 // Itable indices are calculated based on methods array order | |
594 // (see klassItable::compute_itable_index()). Must reinitialize. | |
595 // We assume that since checkconstraints is false, this method | |
596 // cannot throw an exception. An exception here would be | |
597 // problematic since this is the VMThread, not a JavaThread. | |
598 ik->itable()->initialize_itable(false, THREAD); | |
599 } | |
600 | |
601 // Sort methods if the oop is an instanceKlass. | |
602 | |
603 class SortMethodsClosure: public ObjectClosure { | |
604 private: | |
605 Thread* _thread; | |
606 | |
607 public: | |
608 SortMethodsClosure(Thread* thread) : _thread(thread) {} | |
609 | |
610 void do_object(oop obj) { | |
611 // instanceKlass objects need some adjustment. | |
612 if (obj->blueprint()->oop_is_instanceKlass()) { | |
613 instanceKlass* ik = instanceKlass::cast((klassOop)obj); | |
614 | |
615 sort_methods(ik, _thread); | |
616 } | |
617 } | |
618 }; | |
619 | |
620 | |
621 // Adjust references in oops to refer to shared spaces. | |
622 | |
623 class PatchOopsClosure: public ObjectClosure { | |
624 private: | |
625 Thread* _thread; | |
626 ResolveForwardingClosure resolve; | |
627 | |
628 public: | |
629 PatchOopsClosure(Thread* thread) : _thread(thread) {} | |
630 | |
631 void do_object(oop obj) { | |
632 obj->oop_iterate_header(&resolve); | |
633 obj->oop_iterate(&resolve); | |
634 | |
635 assert(obj->klass()->is_shared(), "Klass not pointing into shared space."); | |
636 | |
637 // If the object is a Java object or class which might (in the | |
638 // future) contain a reference to a young gen object, add it to the | |
639 // list. | |
640 | |
641 if (obj->is_klass() || obj->is_instance()) { | |
642 if (obj->is_klass() || | |
1142 | 643 obj->is_a(SystemDictionary::Class_klass()) || |
644 obj->is_a(SystemDictionary::Throwable_klass())) { | |
0 | 645 // Do nothing |
646 } | |
1142 | 647 else if (obj->is_a(SystemDictionary::String_klass())) { |
0 | 648 // immutable objects. |
649 } else { | |
650 // someone added an object we hadn't accounted for. | |
651 ShouldNotReachHere(); | |
652 } | |
653 } | |
654 } | |
655 }; | |
656 | |
657 | |
658 // Empty the young and old generations. | |
659 | |
660 class ClearSpaceClosure : public SpaceClosure { | |
661 public: | |
662 void do_space(Space* s) { | |
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663 s->clear(SpaceDecorator::Mangle); |
0 | 664 } |
665 }; | |
666 | |
667 | |
668 // Closure for serializing initialization data out to a data area to be | |
669 // written to the shared file. | |
670 | |
671 class WriteClosure : public SerializeOopClosure { | |
672 private: | |
673 oop* top; | |
674 char* end; | |
675 | |
676 void out_of_space() { | |
677 warning("\nThe shared miscellaneous data space is not large " | |
678 "enough to \npreload requested classes. Use " | |
679 "-XX:SharedMiscDataSize= to increase \nthe initial " | |
680 "size of the miscellaneous data space.\n"); | |
681 exit(2); | |
682 } | |
683 | |
684 | |
685 inline void check_space() { | |
686 if ((char*)top + sizeof(oop) > end) { | |
687 out_of_space(); | |
688 } | |
689 } | |
690 | |
691 | |
692 public: | |
693 WriteClosure(char* md_top, char* md_end) { | |
694 top = (oop*)md_top; | |
695 end = md_end; | |
696 } | |
697 | |
698 char* get_top() { return (char*)top; } | |
699 | |
700 void do_oop(oop* p) { | |
701 check_space(); | |
702 oop obj = *p; | |
703 assert(obj->is_oop_or_null(), "invalid oop"); | |
704 assert(obj == NULL || obj->is_shared(), | |
705 "Oop in shared space not pointing into shared space."); | |
706 *top = obj; | |
707 ++top; | |
708 } | |
709 | |
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710 void do_oop(narrowOop* pobj) { ShouldNotReachHere(); } |
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711 |
0 | 712 void do_int(int* p) { |
713 check_space(); | |
714 *top = (oop)(intptr_t)*p; | |
715 ++top; | |
716 } | |
717 | |
718 void do_size_t(size_t* p) { | |
719 check_space(); | |
720 *top = (oop)(intptr_t)*p; | |
721 ++top; | |
722 } | |
723 | |
724 void do_ptr(void** p) { | |
725 check_space(); | |
726 *top = (oop)*p; | |
727 ++top; | |
728 } | |
729 | |
730 void do_ptr(HeapWord** p) { do_ptr((void **) p); } | |
731 | |
732 void do_tag(int tag) { | |
733 check_space(); | |
734 *top = (oop)(intptr_t)tag; | |
735 ++top; | |
736 } | |
737 | |
738 void do_region(u_char* start, size_t size) { | |
739 if ((char*)top + size > end) { | |
740 out_of_space(); | |
741 } | |
742 assert((intptr_t)start % sizeof(oop) == 0, "bad alignment"); | |
743 assert(size % sizeof(oop) == 0, "bad size"); | |
744 do_tag((int)size); | |
745 while (size > 0) { | |
746 *top = *(oop*)start; | |
747 ++top; | |
748 start += sizeof(oop); | |
749 size -= sizeof(oop); | |
750 } | |
751 } | |
752 | |
753 bool reading() const { return false; } | |
754 }; | |
755 | |
756 | |
757 class ResolveConstantPoolsClosure : public ObjectClosure { | |
758 private: | |
759 TRAPS; | |
760 public: | |
761 ResolveConstantPoolsClosure(Thread *t) { | |
762 __the_thread__ = t; | |
763 } | |
764 void do_object(oop obj) { | |
765 if (obj->is_constantPool()) { | |
766 constantPoolOop cpool = (constantPoolOop)obj; | |
767 int unresolved = cpool->pre_resolve_shared_klasses(THREAD); | |
768 } | |
769 } | |
770 }; | |
771 | |
772 | |
773 // Print a summary of the contents of the read/write spaces to help | |
774 // identify objects which might be able to be made read-only. At this | |
775 // point, the objects have been written, and we can trash them as | |
776 // needed. | |
777 | |
778 static void print_contents() { | |
779 if (PrintSharedSpaces) { | |
780 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
781 CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen(); | |
782 | |
783 // High level summary of the read-only space: | |
784 | |
785 ClassifyObjectClosure coc; | |
786 tty->cr(); tty->print_cr("ReadOnly space:"); | |
787 gen->ro_space()->object_iterate(&coc); | |
788 coc.print(); | |
789 | |
790 // High level summary of the read-write space: | |
791 | |
792 coc.reset(); | |
793 tty->cr(); tty->print_cr("ReadWrite space:"); | |
794 gen->rw_space()->object_iterate(&coc); | |
795 coc.print(); | |
796 | |
797 // Reset counters | |
798 | |
799 ClearAllocCountClosure cacc; | |
800 gen->ro_space()->object_iterate(&cacc); | |
801 gen->rw_space()->object_iterate(&cacc); | |
802 coc.reset(); | |
803 | |
804 // Lower level summary of the read-only space: | |
805 | |
806 gen->ro_space()->object_iterate(&coc); | |
807 tty->cr(); tty->print_cr("ReadOnly space:"); | |
808 ClassifyInstanceKlassClosure cikc; | |
809 gen->rw_space()->object_iterate(&cikc); | |
810 cikc.print(); | |
811 | |
812 // Reset counters | |
813 | |
814 gen->ro_space()->object_iterate(&cacc); | |
815 gen->rw_space()->object_iterate(&cacc); | |
816 coc.reset(); | |
817 | |
818 // Lower level summary of the read-write space: | |
819 | |
820 gen->rw_space()->object_iterate(&coc); | |
821 cikc.reset(); | |
822 tty->cr(); tty->print_cr("ReadWrite space:"); | |
823 gen->rw_space()->object_iterate(&cikc); | |
824 cikc.print(); | |
825 } | |
826 } | |
827 | |
828 | |
829 // Patch C++ vtable pointer in klass oops. | |
830 | |
831 // Klass objects contain references to c++ vtables in the JVM library. | |
832 // Fix them to point to our constructed vtables. However, don't iterate | |
833 // across the space while doing this, as that causes the vtables to be | |
834 // patched, undoing our useful work. Instead, iterate to make a list, | |
835 // then use the list to do the fixing. | |
408 | 836 // |
837 // Our constructed vtables: | |
838 // Dump time: | |
839 // 1. init_self_patching_vtbl_list: table of pointers to current virtual method addrs | |
840 // 2. generate_vtable_methods: create jump table, appended to above vtbl_list | |
841 // 3. PatchKlassVtables: for Klass list, patch the vtable entry to point to jump table | |
842 // rather than to current vtbl | |
843 // Table layout: NOTE FIXED SIZE | |
844 // 1. vtbl pointers | |
845 // 2. #Klass X #virtual methods per Klass | |
846 // 1 entry for each, in the order: | |
847 // Klass1:method1 entry, Klass1:method2 entry, ... Klass1:method<num_virtuals> entry | |
848 // Klass2:method1 entry, Klass2:method2 entry, ... Klass2:method<num_virtuals> entry | |
849 // ... | |
850 // Klass<vtbl_list_size>:method1 entry, Klass<vtbl_list_size>:method2 entry, | |
851 // ... Klass<vtbl_list_size>:method<num_virtuals> entry | |
852 // Sample entry: (Sparc): | |
853 // save(sp, -256, sp) | |
854 // ba,pt common_code | |
855 // mov XXX, %L0 %L0 gets: Klass index <<8 + method index (note: max method index 255) | |
856 // | |
857 // Restore time: | |
858 // 1. initialize_oops: reserve space for table | |
859 // 2. init_self_patching_vtbl_list: update pointers to NEW virtual method addrs in text | |
860 // | |
861 // Execution time: | |
862 // First virtual method call for any object of these Klass types: | |
863 // 1. object->klass->klass_part | |
864 // 2. vtable entry for that klass_part points to the jump table entries | |
865 // 3. branches to common_code with %O0/klass_part, %L0: Klass index <<8 + method index | |
866 // 4. common_code: | |
867 // Get address of new vtbl pointer for this Klass from updated table | |
868 // Update new vtbl pointer in the Klass: future virtual calls go direct | |
869 // Jump to method, using new vtbl pointer and method index | |
0 | 870 |
871 class PatchKlassVtables: public ObjectClosure { | |
872 private: | |
873 void* _vtbl_ptr; | |
874 VirtualSpace* _md_vs; | |
875 GrowableArray<klassOop>* _klass_objects; | |
876 | |
877 public: | |
878 | |
879 PatchKlassVtables(void* vtbl_ptr, VirtualSpace* md_vs) { | |
880 _vtbl_ptr = vtbl_ptr; | |
881 _md_vs = md_vs; | |
882 _klass_objects = new GrowableArray<klassOop>(); | |
883 } | |
884 | |
885 | |
886 void do_object(oop obj) { | |
887 if (obj->is_klass()) { | |
888 _klass_objects->append(klassOop(obj)); | |
889 } | |
890 } | |
891 | |
892 | |
893 void patch(void** vtbl_list, int vtbl_list_size) { | |
894 for (int i = 0; i < _klass_objects->length(); ++i) { | |
895 klassOop obj = (klassOop)_klass_objects->at(i); | |
896 Klass* k = obj->klass_part(); | |
897 void* v = *(void**)k; | |
898 | |
899 int n; | |
900 for (n = 0; n < vtbl_list_size; ++n) { | |
901 *(void**)k = NULL; | |
902 if (vtbl_list[n] == v) { | |
903 *(void**)k = (void**)_vtbl_ptr + | |
904 (n * CompactingPermGenGen::num_virtuals); | |
905 break; | |
906 } | |
907 } | |
908 guarantee(n < vtbl_list_size, "unable to find matching vtbl pointer"); | |
909 } | |
910 } | |
911 }; | |
912 | |
913 | |
914 // Populate the shared space. | |
915 | |
916 class VM_PopulateDumpSharedSpace: public VM_Operation { | |
917 private: | |
918 GrowableArray<oop> *_class_promote_order; | |
919 OffsetTableContigSpace* _ro_space; | |
920 OffsetTableContigSpace* _rw_space; | |
921 VirtualSpace* _md_vs; | |
922 VirtualSpace* _mc_vs; | |
923 | |
924 public: | |
925 VM_PopulateDumpSharedSpace(GrowableArray<oop> *class_promote_order, | |
926 OffsetTableContigSpace* ro_space, | |
927 OffsetTableContigSpace* rw_space, | |
928 VirtualSpace* md_vs, VirtualSpace* mc_vs) { | |
929 _class_promote_order = class_promote_order; | |
930 _ro_space = ro_space; | |
931 _rw_space = rw_space; | |
932 _md_vs = md_vs; | |
933 _mc_vs = mc_vs; | |
934 } | |
935 | |
936 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; } | |
937 void doit() { | |
938 Thread* THREAD = VMThread::vm_thread(); | |
939 NOT_PRODUCT(SystemDictionary::verify();) | |
940 // The following guarantee is meant to ensure that no loader constraints | |
941 // exist yet, since the constraints table is not shared. This becomes | |
942 // more important now that we don't re-initialize vtables/itables for | |
943 // shared classes at runtime, where constraints were previously created. | |
944 guarantee(SystemDictionary::constraints()->number_of_entries() == 0, | |
945 "loader constraints are not saved"); | |
710 | 946 // Revisit and implement this if we prelink method handle call sites: |
714 | 947 guarantee(SystemDictionary::invoke_method_table() == NULL || |
948 SystemDictionary::invoke_method_table()->number_of_entries() == 0, | |
710 | 949 "invoke method table is not saved"); |
0 | 950 GenCollectedHeap* gch = GenCollectedHeap::heap(); |
951 | |
952 // At this point, many classes have been loaded. | |
953 | |
954 // Update all the fingerprints in the shared methods. | |
955 | |
956 tty->print("Calculating fingerprints ... "); | |
957 FingerprintMethodsClosure fpmc; | |
958 gch->object_iterate(&fpmc); | |
959 tty->print_cr("done. "); | |
960 | |
961 // Remove all references outside the heap. | |
962 | |
963 tty->print("Removing unshareable information ... "); | |
964 RemoveUnshareableInfoClosure ruic; | |
965 gch->object_iterate(&ruic); | |
966 tty->print_cr("done. "); | |
967 | |
968 // Move the objects in three passes. | |
969 | |
970 MarkObjectsOopClosure mark_all; | |
971 MarkCommonReadOnly mark_common_ro; | |
972 MarkCommonSymbols mark_common_symbols; | |
973 MarkStringValues mark_string_values; | |
974 MarkReadWriteObjects mark_rw; | |
975 MarkStringObjects mark_strings; | |
976 MoveMarkedObjects move_ro(_ro_space, true); | |
977 MoveMarkedObjects move_rw(_rw_space, false); | |
978 | |
979 // The SharedOptimizeColdStart VM option governs the new layout | |
980 // algorithm for promoting classes into the shared archive. | |
981 // The general idea is to minimize cold start time by laying | |
982 // out the objects in the order they are accessed at startup time. | |
983 // By doing this we are trying to eliminate out-of-order accesses | |
984 // in the shared archive. This benefits cold startup time by making | |
985 // disk reads as sequential as possible during class loading and | |
986 // bootstrapping activities. There may also be a small secondary | |
987 // effect of better "packing" of more commonly used data on a smaller | |
988 // number of pages, although no direct benefit has been measured from | |
989 // this effect. | |
990 // | |
991 // At the class level of granularity, the promotion order is dictated | |
992 // by the classlist file whose generation is discussed elsewhere. | |
993 // | |
994 // At smaller granularity, optimal ordering was determined by an | |
995 // offline analysis of object access order in the shared archive. | |
996 // The dbx watchpoint facility, combined with SA post-processing, | |
997 // was used to observe common access patterns primarily during | |
998 // classloading. This information was used to craft the promotion | |
999 // order seen in the following closures. | |
1000 // | |
1001 // The observed access order is mostly governed by what happens | |
1002 // in SystemDictionary::load_shared_class(). NOTE WELL - care | |
1003 // should be taken when making changes to this method, because it | |
1004 // may invalidate assumptions made about access order! | |
1005 // | |
1006 // (Ideally, there would be a better way to manage changes to | |
1007 // the access order. Unfortunately a generic in-VM solution for | |
1008 // dynamically observing access order and optimizing shared | |
1009 // archive layout is pretty difficult. We go with the static | |
1010 // analysis because the code is fairly mature at this point | |
1011 // and we're betting that the access order won't change much.) | |
1012 | |
1013 MarkAndMoveOrderedReadOnly mark_and_move_ordered_ro(&move_ro); | |
1014 MarkAndMoveOrderedReadWrite mark_and_move_ordered_rw(&move_rw); | |
1015 | |
1016 // Phase 1a: move commonly used read-only objects to the read-only space. | |
1017 | |
1018 if (SharedOptimizeColdStart) { | |
1019 tty->print("Moving pre-ordered read-only objects to shared space at " PTR_FORMAT " ... ", | |
1020 _ro_space->top()); | |
1021 for (int i = 0; i < _class_promote_order->length(); i++) { | |
1022 oop obj = _class_promote_order->at(i); | |
1023 mark_and_move_ordered_ro.do_object(obj); | |
1024 } | |
1025 tty->print_cr("done. "); | |
1026 } | |
1027 | |
1028 tty->print("Moving read-only objects to shared space at " PTR_FORMAT " ... ", | |
1029 _ro_space->top()); | |
1030 gch->object_iterate(&mark_common_ro); | |
1031 gch->object_iterate(&move_ro); | |
1032 tty->print_cr("done. "); | |
1033 | |
1034 // Phase 1b: move commonly used symbols to the read-only space. | |
1035 | |
1036 tty->print("Moving common symbols to shared space at " PTR_FORMAT " ... ", | |
1037 _ro_space->top()); | |
1038 gch->object_iterate(&mark_common_symbols); | |
1039 gch->object_iterate(&move_ro); | |
1040 tty->print_cr("done. "); | |
1041 | |
1042 // Phase 1c: move remaining symbols to the read-only space | |
1043 // (e.g. String initializers). | |
1044 | |
1045 tty->print("Moving remaining symbols to shared space at " PTR_FORMAT " ... ", | |
1046 _ro_space->top()); | |
1047 vmSymbols::oops_do(&mark_all, true); | |
1048 gch->object_iterate(&move_ro); | |
1049 tty->print_cr("done. "); | |
1050 | |
1051 // Phase 1d: move String character arrays to the read-only space. | |
1052 | |
1053 tty->print("Moving string char arrays to shared space at " PTR_FORMAT " ... ", | |
1054 _ro_space->top()); | |
1055 gch->object_iterate(&mark_string_values); | |
1056 gch->object_iterate(&move_ro); | |
1057 tty->print_cr("done. "); | |
1058 | |
1059 // Phase 2: move all remaining symbols to the read-only space. The | |
1060 // remaining symbols are assumed to be string initializers no longer | |
1061 // referenced. | |
1062 | |
1063 void* extra_symbols = _ro_space->top(); | |
1064 tty->print("Moving additional symbols to shared space at " PTR_FORMAT " ... ", | |
1065 _ro_space->top()); | |
1066 SymbolTable::oops_do(&mark_all); | |
1067 gch->object_iterate(&move_ro); | |
1068 tty->print_cr("done. "); | |
1069 tty->print_cr("Read-only space ends at " PTR_FORMAT ", %d bytes.", | |
1070 _ro_space->top(), _ro_space->used()); | |
1071 | |
1072 // Phase 3: move read-write objects to the read-write space, except | |
1073 // Strings. | |
1074 | |
1075 if (SharedOptimizeColdStart) { | |
1076 tty->print("Moving pre-ordered read-write objects to shared space at " PTR_FORMAT " ... ", | |
1077 _rw_space->top()); | |
1078 for (int i = 0; i < _class_promote_order->length(); i++) { | |
1079 oop obj = _class_promote_order->at(i); | |
1080 mark_and_move_ordered_rw.do_object(obj); | |
1081 } | |
1082 tty->print_cr("done. "); | |
1083 } | |
1084 tty->print("Moving read-write objects to shared space at " PTR_FORMAT " ... ", | |
1085 _rw_space->top()); | |
1086 Universe::oops_do(&mark_all, true); | |
1087 SystemDictionary::oops_do(&mark_all); | |
1088 oop tmp = Universe::arithmetic_exception_instance(); | |
1089 mark_object(java_lang_Throwable::message(tmp)); | |
1090 gch->object_iterate(&mark_rw); | |
1091 gch->object_iterate(&move_rw); | |
1092 tty->print_cr("done. "); | |
1093 | |
1094 // Phase 4: move String objects to the read-write space. | |
1095 | |
1096 tty->print("Moving String objects to shared space at " PTR_FORMAT " ... ", | |
1097 _rw_space->top()); | |
1098 StringTable::oops_do(&mark_all); | |
1099 gch->object_iterate(&mark_strings); | |
1100 gch->object_iterate(&move_rw); | |
1101 tty->print_cr("done. "); | |
1102 tty->print_cr("Read-write space ends at " PTR_FORMAT ", %d bytes.", | |
1103 _rw_space->top(), _rw_space->used()); | |
1104 | |
1105 #ifdef DEBUG | |
1106 // Check: scan for objects which were not moved. | |
1107 | |
1108 CheckRemainingObjects check_objects; | |
1109 gch->object_iterate(&check_objects); | |
1110 check_objects.status(); | |
1111 #endif | |
1112 | |
1113 // Resolve forwarding in objects and saved C++ structures | |
1114 tty->print("Updating references to shared objects ... "); | |
1115 ResolveForwardingClosure resolve; | |
1116 Universe::oops_do(&resolve); | |
1117 SystemDictionary::oops_do(&resolve); | |
1118 StringTable::oops_do(&resolve); | |
1119 SymbolTable::oops_do(&resolve); | |
1120 vmSymbols::oops_do(&resolve); | |
1121 | |
1122 // Set up the share data and shared code segments. | |
1123 | |
1124 char* md_top = _md_vs->low(); | |
1125 char* md_end = _md_vs->high(); | |
1126 char* mc_top = _mc_vs->low(); | |
1127 char* mc_end = _mc_vs->high(); | |
1128 | |
1129 // Reserve space for the list of klassOops whose vtables are used | |
1130 // for patching others as needed. | |
1131 | |
1132 void** vtbl_list = (void**)md_top; | |
1133 int vtbl_list_size = CompactingPermGenGen::vtbl_list_size; | |
1134 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size); | |
1135 | |
1136 md_top += vtbl_list_size * sizeof(void*); | |
1137 void* vtable = md_top; | |
1138 | |
1139 // Reserve space for a new dummy vtable for klass objects in the | |
1140 // heap. Generate self-patching vtable entries. | |
1141 | |
1142 CompactingPermGenGen::generate_vtable_methods(vtbl_list, | |
1143 &vtable, | |
1144 &md_top, md_end, | |
1145 &mc_top, mc_end); | |
1146 | |
1147 // Fix (forward) all of the references in these shared objects (which | |
1148 // are required to point ONLY to objects in the shared spaces). | |
1149 // Also, create a list of all objects which might later contain a | |
1150 // reference to a younger generation object. | |
1151 | |
1152 CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen(); | |
1153 PatchOopsClosure patch(THREAD); | |
1154 gen->ro_space()->object_iterate(&patch); | |
1155 gen->rw_space()->object_iterate(&patch); | |
1156 | |
1157 // Previously method sorting was done concurrently with forwarding | |
1158 // pointer resolution in the shared spaces. This imposed an ordering | |
1159 // restriction in that methods were required to be promoted/patched | |
1160 // before their holder classes. (Because constant pool pointers in | |
1161 // methodKlasses are required to be resolved before their holder class | |
1162 // is visited for sorting, otherwise methods are sorted by incorrect, | |
1163 // pre-forwarding addresses.) | |
1164 // | |
1165 // Now, we reorder methods as a separate step after ALL forwarding | |
1166 // pointer resolution, so that methods can be promoted in any order | |
1167 // with respect to their holder classes. | |
1168 | |
1169 SortMethodsClosure sort(THREAD); | |
1170 gen->ro_space()->object_iterate(&sort); | |
1171 gen->rw_space()->object_iterate(&sort); | |
1172 tty->print_cr("done. "); | |
1173 tty->cr(); | |
1174 | |
1175 // Reorder the system dictionary. (Moving the symbols opps affects | |
1176 // how the hash table indices are calculated.) | |
1177 | |
1178 SystemDictionary::reorder_dictionary(); | |
1179 | |
1180 // Empty the non-shared heap (because most of the objects were | |
1181 // copied out, and the remainder cannot be considered valid oops). | |
1182 | |
1183 ClearSpaceClosure csc; | |
1184 for (int i = 0; i < gch->n_gens(); ++i) { | |
1185 gch->get_gen(i)->space_iterate(&csc); | |
1186 } | |
1187 csc.do_space(gen->the_space()); | |
1188 NOT_PRODUCT(SystemDictionary::verify();) | |
1189 | |
1190 // Copy the String table, the symbol table, and the system | |
1191 // dictionary to the shared space in usable form. Copy the hastable | |
1192 // buckets first [read-write], then copy the linked lists of entries | |
1193 // [read-only]. | |
1194 | |
1195 SymbolTable::reverse(extra_symbols); | |
1196 NOT_PRODUCT(SymbolTable::verify()); | |
1197 SymbolTable::copy_buckets(&md_top, md_end); | |
1198 | |
1199 StringTable::reverse(); | |
1200 NOT_PRODUCT(StringTable::verify()); | |
1201 StringTable::copy_buckets(&md_top, md_end); | |
1202 | |
1203 SystemDictionary::reverse(); | |
1204 SystemDictionary::copy_buckets(&md_top, md_end); | |
1205 | |
1206 ClassLoader::verify(); | |
1207 ClassLoader::copy_package_info_buckets(&md_top, md_end); | |
1208 ClassLoader::verify(); | |
1209 | |
1210 SymbolTable::copy_table(&md_top, md_end); | |
1211 StringTable::copy_table(&md_top, md_end); | |
1212 SystemDictionary::copy_table(&md_top, md_end); | |
1213 ClassLoader::verify(); | |
1214 ClassLoader::copy_package_info_table(&md_top, md_end); | |
1215 ClassLoader::verify(); | |
1216 | |
1217 // Print debug data. | |
1218 | |
1219 if (PrintSharedSpaces) { | |
1220 const char* fmt = "%s space: " PTR_FORMAT " out of " PTR_FORMAT " bytes allocated at " PTR_FORMAT "."; | |
1221 tty->print_cr(fmt, "ro", _ro_space->used(), _ro_space->capacity(), | |
1222 _ro_space->bottom()); | |
1223 tty->print_cr(fmt, "rw", _rw_space->used(), _rw_space->capacity(), | |
1224 _rw_space->bottom()); | |
1225 } | |
1226 | |
1227 // Write the oop data to the output array. | |
1228 | |
1229 WriteClosure wc(md_top, md_end); | |
1230 CompactingPermGenGen::serialize_oops(&wc); | |
1231 md_top = wc.get_top(); | |
1232 | |
1233 // Update the vtable pointers in all of the Klass objects in the | |
1234 // heap. They should point to newly generated vtable. | |
1235 | |
1236 PatchKlassVtables pkvt(vtable, _md_vs); | |
1237 _rw_space->object_iterate(&pkvt); | |
1238 pkvt.patch(vtbl_list, vtbl_list_size); | |
1239 | |
1240 char* saved_vtbl = (char*)malloc(vtbl_list_size * sizeof(void*)); | |
1241 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*)); | |
1242 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*)); | |
1243 | |
1244 // Create and write the archive file that maps the shared spaces. | |
1245 | |
1246 FileMapInfo* mapinfo = new FileMapInfo(); | |
1247 mapinfo->populate_header(gch->gen_policy()->max_alignment()); | |
1248 | |
1249 // Pass 1 - update file offsets in header. | |
1250 mapinfo->write_header(); | |
1251 mapinfo->write_space(CompactingPermGenGen::ro, _ro_space, true); | |
1252 _ro_space->set_saved_mark(); | |
1253 mapinfo->write_space(CompactingPermGenGen::rw, _rw_space, false); | |
1254 _rw_space->set_saved_mark(); | |
1255 mapinfo->write_region(CompactingPermGenGen::md, _md_vs->low(), | |
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1256 pointer_delta(md_top, _md_vs->low(), sizeof(char)), |
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1257 SharedMiscDataSize, |
0 | 1258 false, false); |
1259 mapinfo->write_region(CompactingPermGenGen::mc, _mc_vs->low(), | |
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1260 pointer_delta(mc_top, _mc_vs->low(), sizeof(char)), |
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1261 SharedMiscCodeSize, |
0 | 1262 true, true); |
1263 | |
1264 // Pass 2 - write data. | |
1265 mapinfo->open_for_write(); | |
1266 mapinfo->write_header(); | |
1267 mapinfo->write_space(CompactingPermGenGen::ro, _ro_space, true); | |
1268 mapinfo->write_space(CompactingPermGenGen::rw, _rw_space, false); | |
1269 mapinfo->write_region(CompactingPermGenGen::md, _md_vs->low(), | |
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1270 pointer_delta(md_top, _md_vs->low(), sizeof(char)), |
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1271 SharedMiscDataSize, |
0 | 1272 false, false); |
1273 mapinfo->write_region(CompactingPermGenGen::mc, _mc_vs->low(), | |
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1274 pointer_delta(mc_top, _mc_vs->low(), sizeof(char)), |
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1275 SharedMiscCodeSize, |
0 | 1276 true, true); |
1277 mapinfo->close(); | |
1278 | |
1279 // Summarize heap. | |
1280 memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*)); | |
1281 print_contents(); | |
1282 } | |
1283 }; // class VM_PopulateDumpSharedSpace | |
1284 | |
1285 | |
1286 // Populate the shared spaces and dump to a file. | |
1287 | |
1288 jint CompactingPermGenGen::dump_shared(GrowableArray<oop>* class_promote_order, TRAPS) { | |
1289 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
1290 | |
1291 // Calculate hash values for all of the (interned) strings to avoid | |
1292 // writes to shared pages in the future. | |
1293 | |
1294 tty->print("Calculating hash values for String objects .. "); | |
1295 StringHashCodeClosure shcc(THREAD); | |
1296 StringTable::oops_do(&shcc); | |
1297 tty->print_cr("done. "); | |
1298 | |
1299 CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen(); | |
1300 VM_PopulateDumpSharedSpace op(class_promote_order, | |
1301 gen->ro_space(), gen->rw_space(), | |
1302 gen->md_space(), gen->mc_space()); | |
1303 VMThread::execute(&op); | |
1304 return JNI_OK; | |
1305 } | |
1306 | |
1307 | |
1308 class LinkClassesClosure : public ObjectClosure { | |
1309 private: | |
1310 Thread* THREAD; | |
1311 | |
1312 public: | |
1313 LinkClassesClosure(Thread* thread) : THREAD(thread) {} | |
1314 | |
1315 void do_object(oop obj) { | |
1316 if (obj->is_klass()) { | |
1317 Klass* k = Klass::cast((klassOop) obj); | |
1318 if (k->oop_is_instance()) { | |
1319 instanceKlass* ik = (instanceKlass*) k; | |
1320 // Link the class to cause the bytecodes to be rewritten and the | |
1321 // cpcache to be created. | |
1322 if (ik->get_init_state() < instanceKlass::linked) { | |
1323 ik->link_class(THREAD); | |
1324 guarantee(!HAS_PENDING_EXCEPTION, "exception in class rewriting"); | |
1325 } | |
1326 | |
1327 // Create String objects from string initializer symbols. | |
1328 ik->constants()->resolve_string_constants(THREAD); | |
1329 guarantee(!HAS_PENDING_EXCEPTION, "exception resolving string constants"); | |
1330 } | |
1331 } | |
1332 } | |
1333 }; | |
1334 | |
1335 | |
1336 // Support for a simple checksum of the contents of the class list | |
1337 // file to prevent trivial tampering. The algorithm matches that in | |
1338 // the MakeClassList program used by the J2SE build process. | |
1339 #define JSUM_SEED ((jlong)CONST64(0xcafebabebabecafe)) | |
1340 static jlong | |
1341 jsum(jlong start, const char *buf, const int len) | |
1342 { | |
1343 jlong h = start; | |
1344 char *p = (char *)buf, *e = p + len; | |
1345 while (p < e) { | |
1346 char c = *p++; | |
1347 if (c <= ' ') { | |
1348 /* Skip spaces and control characters */ | |
1349 continue; | |
1350 } | |
1351 h = 31 * h + c; | |
1352 } | |
1353 return h; | |
1354 } | |
1355 | |
1356 | |
1357 | |
1358 | |
1359 | |
1360 // Preload classes from a list, populate the shared spaces and dump to a | |
1361 // file. | |
1362 | |
1363 void GenCollectedHeap::preload_and_dump(TRAPS) { | |
1364 TraceTime timer("Dump Shared Spaces", TraceStartupTime); | |
1365 ResourceMark rm; | |
1366 | |
1367 // Preload classes to be shared. | |
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1368 // Should use some os:: method rather than fopen() here. aB. |
0 | 1369 // Construct the path to the class list (in jre/lib) |
1370 // Walk up two directories from the location of the VM and | |
1371 // optionally tack on "lib" (depending on platform) | |
1372 char class_list_path[JVM_MAXPATHLEN]; | |
1373 os::jvm_path(class_list_path, sizeof(class_list_path)); | |
1374 for (int i = 0; i < 3; i++) { | |
1375 char *end = strrchr(class_list_path, *os::file_separator()); | |
1376 if (end != NULL) *end = '\0'; | |
1377 } | |
1378 int class_list_path_len = (int)strlen(class_list_path); | |
1379 if (class_list_path_len >= 3) { | |
1380 if (strcmp(class_list_path + class_list_path_len - 3, "lib") != 0) { | |
1381 strcat(class_list_path, os::file_separator()); | |
1382 strcat(class_list_path, "lib"); | |
1383 } | |
1384 } | |
1385 strcat(class_list_path, os::file_separator()); | |
1386 strcat(class_list_path, "classlist"); | |
1387 | |
1388 FILE* file = fopen(class_list_path, "r"); | |
1389 if (file != NULL) { | |
1390 jlong computed_jsum = JSUM_SEED; | |
1391 jlong file_jsum = 0; | |
1392 | |
1393 char class_name[256]; | |
1394 int class_count = 0; | |
1395 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
1396 gch->_preloading_shared_classes = true; | |
1397 GrowableArray<oop>* class_promote_order = new GrowableArray<oop>(); | |
1398 | |
1399 // Preload (and intern) strings which will be used later. | |
1400 | |
1401 StringTable::intern("main", THREAD); | |
1402 StringTable::intern("([Ljava/lang/String;)V", THREAD); | |
1403 StringTable::intern("Ljava/lang/Class;", THREAD); | |
1404 | |
1405 StringTable::intern("I", THREAD); // Needed for StringBuffer persistence? | |
1406 StringTable::intern("Z", THREAD); // Needed for StringBuffer persistence? | |
1407 | |
1408 // sun.io.Converters | |
1409 static const char obj_array_sig[] = "[[Ljava/lang/Object;"; | |
1410 SymbolTable::lookup(obj_array_sig, (int)strlen(obj_array_sig), THREAD); | |
1411 | |
1412 // java.util.HashMap | |
1413 static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;"; | |
1414 SymbolTable::lookup(map_entry_array_sig, (int)strlen(map_entry_array_sig), | |
1415 THREAD); | |
1416 | |
1417 tty->print("Loading classes to share ... "); | |
1418 while ((fgets(class_name, sizeof class_name, file)) != NULL) { | |
1419 if (*class_name == '#') { | |
1420 jint fsh, fsl; | |
1421 if (sscanf(class_name, "# %8x%8x\n", &fsh, &fsl) == 2) { | |
1422 file_jsum = ((jlong)(fsh) << 32) | (fsl & 0xffffffff); | |
1423 } | |
1424 | |
1425 continue; | |
1426 } | |
1427 // Remove trailing newline | |
1428 size_t name_len = strlen(class_name); | |
1429 class_name[name_len-1] = '\0'; | |
1430 | |
1431 computed_jsum = jsum(computed_jsum, class_name, (const int)name_len - 1); | |
1432 | |
1433 // Got a class name - load it. | |
1434 symbolHandle class_name_symbol = oopFactory::new_symbol(class_name, | |
1435 THREAD); | |
1436 guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol."); | |
1437 klassOop klass = SystemDictionary::resolve_or_null(class_name_symbol, | |
1438 THREAD); | |
1439 guarantee(!HAS_PENDING_EXCEPTION, "Exception resolving a class."); | |
1440 if (klass != NULL) { | |
1441 if (PrintSharedSpaces) { | |
1442 tty->print_cr("Shared spaces preloaded: %s", class_name); | |
1443 } | |
1444 | |
1445 | |
1446 instanceKlass* ik = instanceKlass::cast(klass); | |
1447 | |
1448 // Should be class load order as per -XX:+TraceClassLoadingPreorder | |
1449 class_promote_order->append(ik->as_klassOop()); | |
1450 | |
1451 // Link the class to cause the bytecodes to be rewritten and the | |
1452 // cpcache to be created. The linking is done as soon as classes | |
1453 // are loaded in order that the related data structures (klass, | |
1454 // cpCache, Sting constants) are located together. | |
1455 | |
1456 if (ik->get_init_state() < instanceKlass::linked) { | |
1457 ik->link_class(THREAD); | |
1458 guarantee(!(HAS_PENDING_EXCEPTION), "exception in class rewriting"); | |
1459 } | |
1460 | |
1461 // Create String objects from string initializer symbols. | |
1462 | |
1463 ik->constants()->resolve_string_constants(THREAD); | |
1464 | |
1465 class_count++; | |
1466 } else { | |
1467 if (PrintSharedSpaces) { | |
1468 tty->cr(); | |
1469 tty->print_cr(" Preload failed: %s", class_name); | |
1470 } | |
1471 } | |
1472 file_jsum = 0; // Checksum must be on last line of file | |
1473 } | |
1474 if (computed_jsum != file_jsum) { | |
1475 tty->cr(); | |
1476 tty->print_cr("Preload failed: checksum of class list was incorrect."); | |
1477 exit(1); | |
1478 } | |
1479 | |
1480 tty->print_cr("done. "); | |
1481 | |
1482 if (PrintSharedSpaces) { | |
1483 tty->print_cr("Shared spaces: preloaded %d classes", class_count); | |
1484 } | |
1485 | |
1486 // Rewrite and unlink classes. | |
1487 tty->print("Rewriting and unlinking classes ... "); | |
1488 // Make heap parsable | |
1489 ensure_parsability(false); // arg is actually don't care | |
1490 | |
1491 // Link any classes which got missed. (It's not quite clear why | |
1492 // they got missed.) This iteration would be unsafe if we weren't | |
1493 // single-threaded at this point; however we can't do it on the VM | |
1494 // thread because it requires object allocation. | |
1495 LinkClassesClosure lcc(Thread::current()); | |
1496 object_iterate(&lcc); | |
1497 tty->print_cr("done. "); | |
1498 | |
1499 // Create and dump the shared spaces. | |
1500 jint err = CompactingPermGenGen::dump_shared(class_promote_order, THREAD); | |
1501 if (err != JNI_OK) { | |
1502 fatal("Dumping shared spaces failed."); | |
1503 } | |
1504 | |
1505 } else { | |
1506 char errmsg[JVM_MAXPATHLEN]; | |
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1507 os::lasterror(errmsg, JVM_MAXPATHLEN); |
0 | 1508 tty->print_cr("Loading classlist failed: %s", errmsg); |
1509 exit(1); | |
1510 } | |
1511 | |
1512 // Since various initialization steps have been undone by this process, | |
1513 // it is not reasonable to continue running a java process. | |
1514 exit(0); | |
1515 } |