1 #ifdef USE_PRAGMA_IDENT_SRC
2 #pragma ident "@(#)dump.cpp 1.33 07/05/23 10:53:38 JVM"
3 #endif
4 /*
5 * Copyright 2003-2007 Sun Microsystems, Inc. All Rights Reserved.
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
7 *
8 * This code is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 only, as
10 * published by the Free Software Foundation.
11 *
12 * This code is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * version 2 for more details (a copy is included in the LICENSE file that
16 * accompanied this code).
17 *
18 * You should have received a copy of the GNU General Public License version
19 * 2 along with this work; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
24 * have any questions.
25 *
26 */
27
28 # include "incls/_precompiled.incl"
29 # include "incls/_dump.cpp.incl"
30
31
32 // Closure to set up the fingerprint field for all methods.
33
34 class FingerprintMethodsClosure: public ObjectClosure {
35 public:
36 void do_object(oop obj) {
37 if (obj->is_method()) {
38 methodOop mobj = (methodOop)obj;
39 ResourceMark rm;
40 (new Fingerprinter(mobj))->fingerprint();
41 }
42 }
43 };
44
45
46
47 // Closure to set the hash value (String.hash field) in all of the
48 // String objects in the heap. Setting the hash value is not required.
49 // However, setting the value in advance prevents the value from being
50 // written later, increasing the likelihood that the shared page contain
51 // the hash can be shared.
52 //
53 // NOTE THAT the algorithm in StringTable::hash_string() MUST MATCH the
54 // algorithm in java.lang.String.hashCode().
55
56 class StringHashCodeClosure: public OopClosure {
57 private:
58 Thread* THREAD;
59 int hash_offset;
60 public:
61 StringHashCodeClosure(Thread* t) {
62 THREAD = t;
63 hash_offset = java_lang_String::hash_offset_in_bytes();
64 }
65
66 void do_oop(oop* pobj) {
67 if (pobj != NULL) {
68 oop obj = *pobj;
69 if (obj->klass() == SystemDictionary::string_klass()) {
70
71 int hash;
72 typeArrayOop value = java_lang_String::value(obj);
73 int length = java_lang_String::length(obj);
74 if (length == 0) {
75 hash = 0;
76 } else {
77 int offset = java_lang_String::offset(obj);
78 jchar* s = value->char_at_addr(offset);
79 hash = StringTable::hash_string(s, length);
80 }
81 obj->int_field_put(hash_offset, hash);
82 }
83 }
84 }
85 };
86
87
88 // Remove data from objects which should not appear in the shared file
89 // (as it pertains only to the current JVM).
90
91 class RemoveUnshareableInfoClosure : public ObjectClosure {
92 public:
93 void do_object(oop obj) {
94 // Zap data from the objects which is pertains only to this JVM. We
95 // want that data recreated in new JVMs when the shared file is used.
96 if (obj->is_method()) {
97 ((methodOop)obj)->remove_unshareable_info();
98 }
99 else if (obj->is_klass()) {
100 Klass::cast((klassOop)obj)->remove_unshareable_info();
101 }
102
103 // Don't save compiler related special oops (shouldn't be any yet).
104 if (obj->is_methodData() || obj->is_compiledICHolder()) {
105 ShouldNotReachHere();
106 }
107 }
108 };
109
110
111 static bool mark_object(oop obj) {
112 if (obj != NULL &&
113 !obj->is_shared() &&
114 !obj->is_forwarded() &&
115 !obj->is_gc_marked()) {
116 obj->set_mark(markOopDesc::prototype()->set_marked());
117 return true;
118 }
119
120 return false;
121 }
122
123 // Closure: mark objects closure.
124
125 class MarkObjectsOopClosure : public OopClosure {
126 public:
127 void do_oop(oop* pobj) {
128 mark_object(*pobj);
129 }
130 };
131
132
133 class MarkObjectsSkippingKlassesOopClosure : public OopClosure {
134 public:
135 void do_oop(oop* pobj) {
136 oop obj = *pobj;
137 if (obj != NULL &&
138 !obj->is_klass()) {
139 mark_object(obj);
140 }
141 }
142 };
143
144
145 static void mark_object_recursive_skipping_klasses(oop obj) {
146 mark_object(obj);
147 if (obj != NULL) {
148 MarkObjectsSkippingKlassesOopClosure mark_all;
149 obj->oop_iterate(&mark_all);
150 }
151 }
152
153
154 // Closure: mark common read-only objects, excluding symbols
155
156 class MarkCommonReadOnly : public ObjectClosure {
157 private:
158 MarkObjectsOopClosure mark_all;
159 public:
160 void do_object(oop obj) {
161
162 // Mark all constMethod objects.
163
164 if (obj->is_constMethod()) {
165 mark_object(obj);
166 mark_object(constMethodOop(obj)->stackmap_data());
167 // Exception tables are needed by ci code during compilation.
168 mark_object(constMethodOop(obj)->exception_table());
169 }
170
171 // Mark objects referenced by klass objects which are read-only.
172
173 else if (obj->is_klass()) {
174 Klass* k = Klass::cast((klassOop)obj);
175 mark_object(k->secondary_supers());
176
177 // The METHODS() OBJARRAYS CANNOT BE MADE READ-ONLY, even though
178 // it is never modified. Otherwise, they will be pre-marked; the
179 // GC marking phase will skip them; and by skipping them will fail
180 // to mark the methods objects referenced by the array.
181
182 if (obj->blueprint()->oop_is_instanceKlass()) {
183 instanceKlass* ik = instanceKlass::cast((klassOop)obj);
184 mark_object(ik->method_ordering());
185 mark_object(ik->local_interfaces());
186 mark_object(ik->transitive_interfaces());
187 mark_object(ik->fields());
188
189 mark_object(ik->class_annotations());
190
191 mark_object_recursive_skipping_klasses(ik->fields_annotations());
192 mark_object_recursive_skipping_klasses(ik->methods_annotations());
193 mark_object_recursive_skipping_klasses(ik->methods_parameter_annotations());
194 mark_object_recursive_skipping_klasses(ik->methods_default_annotations());
195
196 typeArrayOop inner_classes = ik->inner_classes();
197 if (inner_classes != NULL) {
198 mark_object(inner_classes);
199 }
200 }
201 }
202 }
203 };
204
205
206 // Closure: mark common symbols
207
208 class MarkCommonSymbols : public ObjectClosure {
209 private:
210 MarkObjectsOopClosure mark_all;
211 public:
212 void do_object(oop obj) {
213
214 // Mark symbols refered to by method objects.
215
216 if (obj->is_method()) {
217 methodOop m = methodOop(obj);
218 mark_object(m->name());
219 mark_object(m->signature());
220 }
221
222 // Mark symbols referenced by klass objects which are read-only.
223
224 else if (obj->is_klass()) {
225
226 if (obj->blueprint()->oop_is_instanceKlass()) {
227 instanceKlass* ik = instanceKlass::cast((klassOop)obj);
228 mark_object(ik->name());
229 mark_object(ik->generic_signature());
230 mark_object(ik->source_file_name());
231 mark_object(ik->source_debug_extension());
232
233 typeArrayOop inner_classes = ik->inner_classes();
234 if (inner_classes != NULL) {
235 int length = inner_classes->length();
236 for (int i = 0;
237 i < length;
238 i += instanceKlass::inner_class_next_offset) {
239 int ioff = i + instanceKlass::inner_class_inner_name_offset;
240 int index = inner_classes->ushort_at(ioff);
241 if (index != 0) {
242 mark_object(ik->constants()->symbol_at(index));
243 }
244 }
245 }
246 ik->field_names_and_sigs_iterate(&mark_all);
247 }
248 }
249
250 // Mark symbols referenced by other constantpool entries.
251
252 if (obj->is_constantPool()) {
253 constantPoolOop(obj)->shared_symbols_iterate(&mark_all);
254 }
255 }
256 };
257
258
259 // Closure: mark char arrays used by strings
260
261 class MarkStringValues : public ObjectClosure {
262 private:
263 MarkObjectsOopClosure mark_all;
264 public:
265 void do_object(oop obj) {
266
267 // Character arrays referenced by String objects are read-only.
268
269 if (java_lang_String::is_instance(obj)) {
270 mark_object(java_lang_String::value(obj));
271 }
272 }
273 };
274
275
276 #ifdef DEBUG
277 // Closure: Check for objects left in the heap which have not been moved.
278
279 class CheckRemainingObjects : public ObjectClosure {
280 private:
281 int count;
282
283 public:
284 CheckRemainingObjects() {
285 count = 0;
286 }
287
288 void do_object(oop obj) {
289 if (!obj->is_shared() &&
290 !obj->is_forwarded()) {
291 ++count;
292 if (Verbose) {
293 tty->print("Unreferenced object: ");
294 obj->print_on(tty);
295 }
296 }
297 }
298
299 void status() {
300 tty->print_cr("%d objects no longer referenced, not shared.", count);
301 }
302 };
303 #endif
304
305
306 // Closure: Mark remaining objects read-write, except Strings.
307
308 class MarkReadWriteObjects : public ObjectClosure {
309 private:
310 MarkObjectsOopClosure mark_objects;
311 public:
312 void do_object(oop obj) {
313
314 // The METHODS() OBJARRAYS CANNOT BE MADE READ-ONLY, even though
315 // it is never modified. Otherwise, they will be pre-marked; the
316 // GC marking phase will skip them; and by skipping them will fail
317 // to mark the methods objects referenced by the array.
318
319 if (obj->is_klass()) {
320 mark_object(obj);
321 Klass* k = klassOop(obj)->klass_part();
322 mark_object(k->java_mirror());
323 if (obj->blueprint()->oop_is_instanceKlass()) {
324 instanceKlass* ik = (instanceKlass*)k;
325 mark_object(ik->methods());
326 mark_object(ik->constants());
327 }
328 if (obj->blueprint()->oop_is_javaArray()) {
329 arrayKlass* ak = (arrayKlass*)k;
330 mark_object(ak->component_mirror());
331 }
332 return;
333 }
334
335 // Mark constantPool tags and the constantPoolCache.
336
337 else if (obj->is_constantPool()) {
338 constantPoolOop pool = constantPoolOop(obj);
339 mark_object(pool->cache());
340 pool->shared_tags_iterate(&mark_objects);
341 return;
342 }
343
344 // Mark all method objects.
345
346 if (obj->is_method()) {
347 mark_object(obj);
348 }
349 }
350 };
351
352
353 // Closure: Mark String objects read-write.
354
355 class MarkStringObjects : public ObjectClosure {
356 private:
357 MarkObjectsOopClosure mark_objects;
358 public:
359 void do_object(oop obj) {
360
361 // Mark String objects referenced by constant pool entries.
362
363 if (obj->is_constantPool()) {
364 constantPoolOop pool = constantPoolOop(obj);
365 pool->shared_strings_iterate(&mark_objects);
366 return;
367 }
368 }
369 };
370
371
372 // Move objects matching specified type (ie. lock_bits) to the specified
373 // space.
374
375 class MoveMarkedObjects : public ObjectClosure {
376 private:
377 OffsetTableContigSpace* _space;
378 bool _read_only;
379
380 public:
381 MoveMarkedObjects(OffsetTableContigSpace* space, bool read_only) {
382 _space = space;
383 _read_only = read_only;
384 }
385
386 void do_object(oop obj) {
387 if (obj->is_shared()) {
388 return;
389 }
390 if (obj->is_gc_marked() && obj->forwardee() == NULL) {
391 int s = obj->size();
392 oop sh_obj = (oop)_space->allocate(s);
393 if (sh_obj == NULL) {
394 if (_read_only) {
395 warning("\nThe permanent generation read only space is not large "
396 "enough to \npreload requested classes. Use "
397 "-XX:SharedReadOnlySize= to increase \nthe initial "
398 "size of the read only space.\n");
399 } else {
400 warning("\nThe permanent generation read write space is not large "
401 "enough to \npreload requested classes. Use "
402 "-XX:SharedReadWriteSize= to increase \nthe initial "
403 "size of the read write space.\n");
404 }
405 exit(2);
406 }
407 if (PrintSharedSpaces && Verbose && WizardMode) {
408 tty->print_cr("\nMoveMarkedObjects: " PTR_FORMAT " -> " PTR_FORMAT " %s", obj, sh_obj,
409 (_read_only ? "ro" : "rw"));
410 }
411 Copy::aligned_disjoint_words((HeapWord*)obj, (HeapWord*)sh_obj, s);
412 obj->forward_to(sh_obj);
413 if (_read_only) {
414 // Readonly objects: set hash value to self pointer and make gc_marked.
415 sh_obj->forward_to(sh_obj);
416 } else {
417 sh_obj->init_mark();
418 }
419 }
420 }
421 };
422
423 static void mark_and_move(oop obj, MoveMarkedObjects* move) {
424 if (mark_object(obj)) move->do_object(obj);
425 }
426
427 enum order_policy {
428 OP_favor_startup = 0,
429 OP_balanced = 1,
430 OP_favor_runtime = 2
431 };
432
433 static void mark_and_move_for_policy(order_policy policy, oop obj, MoveMarkedObjects* move) {
434 if (SharedOptimizeColdStartPolicy >= policy) mark_and_move(obj, move);
435 }
436
437 class MarkAndMoveOrderedReadOnly : public ObjectClosure {
438 private:
439 MoveMarkedObjects *_move_ro;
440
441 public:
442 MarkAndMoveOrderedReadOnly(MoveMarkedObjects *move_ro) : _move_ro(move_ro) {}
443
444 void do_object(oop obj) {
445 if (obj->is_klass() && obj->blueprint()->oop_is_instanceKlass()) {
446 instanceKlass* ik = instanceKlass::cast((klassOop)obj);
447 int i;
448
449 mark_and_move_for_policy(OP_favor_startup, ik->name(), _move_ro);
450
451 if (ik->super() != NULL) {
452 do_object(ik->super());
453 }
454
455 objArrayOop interfaces = ik->local_interfaces();
456 mark_and_move_for_policy(OP_favor_startup, interfaces, _move_ro);
457 for(i = 0; i < interfaces->length(); i++) {
458 klassOop k = klassOop(interfaces->obj_at(i));
459 mark_and_move_for_policy(OP_favor_startup, k->klass_part()->name(), _move_ro);
460 do_object(k);
461 }
462
463 objArrayOop methods = ik->methods();
464 for(i = 0; i < methods->length(); i++) {
465 methodOop m = methodOop(methods->obj_at(i));
466 mark_and_move_for_policy(OP_favor_startup, m->constMethod(), _move_ro);
467 mark_and_move_for_policy(OP_favor_runtime, m->constMethod()->exception_table(), _move_ro);
468 mark_and_move_for_policy(OP_favor_runtime, m->constMethod()->stackmap_data(), _move_ro);
469
470 // We don't move the name symbolOop here because it may invalidate
471 // method ordering, which is dependent on the address of the name
472 // symbolOop. It will get promoted later with the other symbols.
473 // Method name is rarely accessed during classloading anyway.
474 // mark_and_move_for_policy(OP_balanced, m->name(), _move_ro);
475
476 mark_and_move_for_policy(OP_favor_startup, m->signature(), _move_ro);
477 }
478
479 mark_and_move_for_policy(OP_favor_startup, ik->transitive_interfaces(), _move_ro);
480 mark_and_move_for_policy(OP_favor_startup, ik->fields(), _move_ro);
481
482 mark_and_move_for_policy(OP_favor_runtime, ik->secondary_supers(), _move_ro);
483 mark_and_move_for_policy(OP_favor_runtime, ik->method_ordering(), _move_ro);
484 mark_and_move_for_policy(OP_favor_runtime, ik->class_annotations(), _move_ro);
485 mark_and_move_for_policy(OP_favor_runtime, ik->fields_annotations(), _move_ro);
486 mark_and_move_for_policy(OP_favor_runtime, ik->methods_annotations(), _move_ro);
487 mark_and_move_for_policy(OP_favor_runtime, ik->methods_parameter_annotations(), _move_ro);
488 mark_and_move_for_policy(OP_favor_runtime, ik->methods_default_annotations(), _move_ro);
489 mark_and_move_for_policy(OP_favor_runtime, ik->inner_classes(), _move_ro);
490 mark_and_move_for_policy(OP_favor_runtime, ik->secondary_supers(), _move_ro);
491 }
492 }
493 };
494
495 class MarkAndMoveOrderedReadWrite: public ObjectClosure {
496 private:
497 MoveMarkedObjects *_move_rw;
498
499 public:
500 MarkAndMoveOrderedReadWrite(MoveMarkedObjects *move_rw) : _move_rw(move_rw) {}
501
502 void do_object(oop obj) {
503 if (obj->is_klass() && obj->blueprint()->oop_is_instanceKlass()) {
504 instanceKlass* ik = instanceKlass::cast((klassOop)obj);
505 int i;
506
507 mark_and_move_for_policy(OP_favor_startup, ik->as_klassOop(), _move_rw);
508
509 if (ik->super() != NULL) {
510 do_object(ik->super());
511 }
512
513 objArrayOop interfaces = ik->local_interfaces();
514 for(i = 0; i < interfaces->length(); i++) {
515 klassOop k = klassOop(interfaces->obj_at(i));
516 mark_and_move_for_policy(OP_favor_startup, k, _move_rw);
517 do_object(k);
518 }
519
520 objArrayOop methods = ik->methods();
521 mark_and_move_for_policy(OP_favor_startup, methods, _move_rw);
522 for(i = 0; i < methods->length(); i++) {
523 methodOop m = methodOop(methods->obj_at(i));
524 mark_and_move_for_policy(OP_favor_startup, m, _move_rw);
525 mark_and_move_for_policy(OP_favor_startup, ik->constants(), _move_rw); // idempotent
526 mark_and_move_for_policy(OP_balanced, ik->constants()->cache(), _move_rw); // idempotent
527 mark_and_move_for_policy(OP_balanced, ik->constants()->tags(), _move_rw); // idempotent
528 }
529
530 mark_and_move_for_policy(OP_favor_startup, ik->as_klassOop()->klass(), _move_rw);
531 mark_and_move_for_policy(OP_favor_startup, ik->constants()->klass(), _move_rw);
532
533 // Although Java mirrors are marked in MarkReadWriteObjects,
534 // apparently they were never moved into shared spaces since
535 // MoveMarkedObjects skips marked instance oops. This may
536 // be a bug in the original implementation or simply the vestige
537 // of an abandoned experiment. Nevertheless we leave a hint
538 // here in case this capability is ever correctly implemented.
539 //
540 // mark_and_move_for_policy(OP_favor_runtime, ik->java_mirror(), _move_rw);
541 }
542 }
543
544 };
545
546 // Adjust references in oops to refer to shared spaces.
547
548 class ResolveForwardingClosure: public OopClosure {
549 public:
550 void do_oop(oop* p) {
551 oop obj = *p;
552 if (!obj->is_shared()) {
553 if (obj != NULL) {
554 oop f = obj->forwardee();
555 guarantee(f->is_shared(), "Oop doesn't refer to shared space.");
556 *p = f;
557 }
558 }
559 }
560 };
561
562
563 void sort_methods(instanceKlass* ik, TRAPS) {
564 klassOop super = ik->super();
565 if (super != NULL) {
566 sort_methods(instanceKlass::cast(super), THREAD);
567 }
568
569 // The methods array must be ordered by symbolOop address. (See
570 // classFileParser.cpp where methods in a class are originally
571 // sorted.) Since objects have just be reordered, this must be
572 // corrected.
573 methodOopDesc::sort_methods(ik->methods(),
574 ik->methods_annotations(),
575 ik->methods_parameter_annotations(),
576 ik->methods_default_annotations(),
577 true /* idempotent, slow */);
578
579 // Itable indices are calculated based on methods array order
580 // (see klassItable::compute_itable_index()). Must reinitialize.
581 // We assume that since checkconstraints is false, this method
582 // cannot throw an exception. An exception here would be
583 // problematic since this is the VMThread, not a JavaThread.
584 ik->itable()->initialize_itable(false, THREAD);
585 }
586
587 // Sort methods if the oop is an instanceKlass.
588
589 class SortMethodsClosure: public ObjectClosure {
590 private:
591 Thread* _thread;
592
593 public:
594 SortMethodsClosure(Thread* thread) : _thread(thread) {}
595
596 void do_object(oop obj) {
597 // instanceKlass objects need some adjustment.
598 if (obj->blueprint()->oop_is_instanceKlass()) {
599 instanceKlass* ik = instanceKlass::cast((klassOop)obj);
600
601 sort_methods(ik, _thread);
602 }
603 }
604 };
605
606
607 // Adjust references in oops to refer to shared spaces.
608
609 class PatchOopsClosure: public ObjectClosure {
610 private:
611 Thread* _thread;
612 ResolveForwardingClosure resolve;
613
614 public:
615 PatchOopsClosure(Thread* thread) : _thread(thread) {}
616
617 void do_object(oop obj) {
618 obj->oop_iterate_header(&resolve);
619 obj->oop_iterate(&resolve);
620
621 assert(obj->klass()->is_shared(), "Klass not pointing into shared space.");
622
623 // If the object is a Java object or class which might (in the
624 // future) contain a reference to a young gen object, add it to the
625 // list.
626
627 if (obj->is_klass() || obj->is_instance()) {
628 if (obj->is_klass() ||
629 obj->is_a(SystemDictionary::class_klass()) ||
630 obj->is_a(SystemDictionary::throwable_klass())) {
631 // Do nothing
632 }
633 else if (obj->is_a(SystemDictionary::string_klass())) {
634 // immutable objects.
635 } else {
636 // someone added an object we hadn't accounted for.
637 ShouldNotReachHere();
638 }
639 }
640 }
641 };
642
643
644 // Empty the young and old generations.
645
646 class ClearSpaceClosure : public SpaceClosure {
647 public:
648 void do_space(Space* s) {
649 s->clear();
650 }
651 };
652
653
654 // Closure for serializing initialization data out to a data area to be
655 // written to the shared file.
656
657 class WriteClosure : public SerializeOopClosure {
658 private:
659 oop* top;
660 char* end;
661
662 void out_of_space() {
663 warning("\nThe shared miscellaneous data space is not large "
664 "enough to \npreload requested classes. Use "
665 "-XX:SharedMiscDataSize= to increase \nthe initial "
666 "size of the miscellaneous data space.\n");
667 exit(2);
668 }
669
670
671 inline void check_space() {
672 if ((char*)top + sizeof(oop) > end) {
673 out_of_space();
674 }
675 }
676
677
678 public:
679 WriteClosure(char* md_top, char* md_end) {
680 top = (oop*)md_top;
681 end = md_end;
682 }
683
684 char* get_top() { return (char*)top; }
685
686 void do_oop(oop* p) {
687 check_space();
688 oop obj = *p;
689 assert(obj->is_oop_or_null(), "invalid oop");
690 assert(obj == NULL || obj->is_shared(),
691 "Oop in shared space not pointing into shared space.");
692 *top = obj;
693 ++top;
694 }
695
696 void do_int(int* p) {
697 check_space();
698 *top = (oop)(intptr_t)*p;
699 ++top;
700 }
701
702 void do_size_t(size_t* p) {
703 check_space();
704 *top = (oop)(intptr_t)*p;
705 ++top;
706 }
707
708 void do_ptr(void** p) {
709 check_space();
710 *top = (oop)*p;
711 ++top;
712 }
713
714 void do_ptr(HeapWord** p) { do_ptr((void **) p); }
715
716 void do_tag(int tag) {
717 check_space();
718 *top = (oop)(intptr_t)tag;
719 ++top;
720 }
721
722 void do_region(u_char* start, size_t size) {
723 if ((char*)top + size > end) {
724 out_of_space();
725 }
726 assert((intptr_t)start % sizeof(oop) == 0, "bad alignment");
727 assert(size % sizeof(oop) == 0, "bad size");
728 do_tag((int)size);
729 while (size > 0) {
730 *top = *(oop*)start;
731 ++top;
732 start += sizeof(oop);
733 size -= sizeof(oop);
734 }
735 }
736
737 bool reading() const { return false; }
738 };
739
740
741 class ResolveConstantPoolsClosure : public ObjectClosure {
742 private:
743 TRAPS;
744 public:
745 ResolveConstantPoolsClosure(Thread *t) {
746 __the_thread__ = t;
747 }
748 void do_object(oop obj) {
749 if (obj->is_constantPool()) {
750 constantPoolOop cpool = (constantPoolOop)obj;
751 int unresolved = cpool->pre_resolve_shared_klasses(THREAD);
752 }
753 }
754 };
755
756
757 // Print a summary of the contents of the read/write spaces to help
758 // identify objects which might be able to be made read-only. At this
759 // point, the objects have been written, and we can trash them as
760 // needed.
761
762 static void print_contents() {
763 if (PrintSharedSpaces) {
764 GenCollectedHeap* gch = GenCollectedHeap::heap();
765 CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen();
766
767 // High level summary of the read-only space:
768
769 ClassifyObjectClosure coc;
770 tty->cr(); tty->print_cr("ReadOnly space:");
771 gen->ro_space()->object_iterate(&coc);
772 coc.print();
773
774 // High level summary of the read-write space:
775
776 coc.reset();
777 tty->cr(); tty->print_cr("ReadWrite space:");
778 gen->rw_space()->object_iterate(&coc);
779 coc.print();
780
781 // Reset counters
782
783 ClearAllocCountClosure cacc;
784 gen->ro_space()->object_iterate(&cacc);
785 gen->rw_space()->object_iterate(&cacc);
786 coc.reset();
787
788 // Lower level summary of the read-only space:
789
790 gen->ro_space()->object_iterate(&coc);
791 tty->cr(); tty->print_cr("ReadOnly space:");
792 ClassifyInstanceKlassClosure cikc;
793 gen->rw_space()->object_iterate(&cikc);
794 cikc.print();
795
796 // Reset counters
797
798 gen->ro_space()->object_iterate(&cacc);
799 gen->rw_space()->object_iterate(&cacc);
800 coc.reset();
801
802 // Lower level summary of the read-write space:
803
804 gen->rw_space()->object_iterate(&coc);
805 cikc.reset();
806 tty->cr(); tty->print_cr("ReadWrite space:");
807 gen->rw_space()->object_iterate(&cikc);
808 cikc.print();
809 }
810 }
811
812
813 // Patch C++ vtable pointer in klass oops.
814
815 // Klass objects contain references to c++ vtables in the JVM library.
816 // Fix them to point to our constructed vtables. However, don't iterate
817 // across the space while doing this, as that causes the vtables to be
818 // patched, undoing our useful work. Instead, iterate to make a list,
819 // then use the list to do the fixing.
820
821 class PatchKlassVtables: public ObjectClosure {
822 private:
823 void* _vtbl_ptr;
824 VirtualSpace* _md_vs;
825 GrowableArray<klassOop>* _klass_objects;
826
827 public:
828
829 PatchKlassVtables(void* vtbl_ptr, VirtualSpace* md_vs) {
830 _vtbl_ptr = vtbl_ptr;
831 _md_vs = md_vs;
832 _klass_objects = new GrowableArray<klassOop>();
833 }
834
835
836 void do_object(oop obj) {
837 if (obj->is_klass()) {
838 _klass_objects->append(klassOop(obj));
839 }
840 }
841
842
843 void patch(void** vtbl_list, int vtbl_list_size) {
844 for (int i = 0; i < _klass_objects->length(); ++i) {
845 klassOop obj = (klassOop)_klass_objects->at(i);
846 Klass* k = obj->klass_part();
847 void* v = *(void**)k;
848
849 int n;
850 for (n = 0; n < vtbl_list_size; ++n) {
851 *(void**)k = NULL;
852 if (vtbl_list[n] == v) {
853 *(void**)k = (void**)_vtbl_ptr +
854 (n * CompactingPermGenGen::num_virtuals);
855 break;
856 }
857 }
858 guarantee(n < vtbl_list_size, "unable to find matching vtbl pointer");
859 }
860 }
861 };
862
863
864 // Populate the shared space.
865
866 class VM_PopulateDumpSharedSpace: public VM_Operation {
867 private:
868 GrowableArray<oop> *_class_promote_order;
869 OffsetTableContigSpace* _ro_space;
870 OffsetTableContigSpace* _rw_space;
871 VirtualSpace* _md_vs;
872 VirtualSpace* _mc_vs;
873
874 public:
875 VM_PopulateDumpSharedSpace(GrowableArray<oop> *class_promote_order,
876 OffsetTableContigSpace* ro_space,
877 OffsetTableContigSpace* rw_space,
878 VirtualSpace* md_vs, VirtualSpace* mc_vs) {
879 _class_promote_order = class_promote_order;
880 _ro_space = ro_space;
881 _rw_space = rw_space;
882 _md_vs = md_vs;
883 _mc_vs = mc_vs;
884 }
885
886 VMOp_Type type() const { return VMOp_PopulateDumpSharedSpace; }
887 void doit() {
888 Thread* THREAD = VMThread::vm_thread();
889 NOT_PRODUCT(SystemDictionary::verify();)
890 // The following guarantee is meant to ensure that no loader constraints
891 // exist yet, since the constraints table is not shared. This becomes
892 // more important now that we don't re-initialize vtables/itables for
893 // shared classes at runtime, where constraints were previously created.
894 guarantee(SystemDictionary::constraints()->number_of_entries() == 0,
895 "loader constraints are not saved");
896 GenCollectedHeap* gch = GenCollectedHeap::heap();
897
898 // At this point, many classes have been loaded.
899
900 // Update all the fingerprints in the shared methods.
901
902 tty->print("Calculating fingerprints ... ");
903 FingerprintMethodsClosure fpmc;
904 gch->object_iterate(&fpmc);
905 tty->print_cr("done. ");
906
907 // Remove all references outside the heap.
908
909 tty->print("Removing unshareable information ... ");
910 RemoveUnshareableInfoClosure ruic;
911 gch->object_iterate(&ruic);
912 tty->print_cr("done. ");
913
914 // Move the objects in three passes.
915
916 MarkObjectsOopClosure mark_all;
917 MarkCommonReadOnly mark_common_ro;
918 MarkCommonSymbols mark_common_symbols;
919 MarkStringValues mark_string_values;
920 MarkReadWriteObjects mark_rw;
921 MarkStringObjects mark_strings;
922 MoveMarkedObjects move_ro(_ro_space, true);
923 MoveMarkedObjects move_rw(_rw_space, false);
924
925 // The SharedOptimizeColdStart VM option governs the new layout
926 // algorithm for promoting classes into the shared archive.
927 // The general idea is to minimize cold start time by laying
928 // out the objects in the order they are accessed at startup time.
929 // By doing this we are trying to eliminate out-of-order accesses
930 // in the shared archive. This benefits cold startup time by making
931 // disk reads as sequential as possible during class loading and
932 // bootstrapping activities. There may also be a small secondary
933 // effect of better "packing" of more commonly used data on a smaller
934 // number of pages, although no direct benefit has been measured from
935 // this effect.
936 //
937 // At the class level of granularity, the promotion order is dictated
938 // by the classlist file whose generation is discussed elsewhere.
939 //
940 // At smaller granularity, optimal ordering was determined by an
941 // offline analysis of object access order in the shared archive.
942 // The dbx watchpoint facility, combined with SA post-processing,
943 // was used to observe common access patterns primarily during
944 // classloading. This information was used to craft the promotion
945 // order seen in the following closures.
946 //
947 // The observed access order is mostly governed by what happens
948 // in SystemDictionary::load_shared_class(). NOTE WELL - care
949 // should be taken when making changes to this method, because it
950 // may invalidate assumptions made about access order!
951 //
952 // (Ideally, there would be a better way to manage changes to
953 // the access order. Unfortunately a generic in-VM solution for
954 // dynamically observing access order and optimizing shared
955 // archive layout is pretty difficult. We go with the static
956 // analysis because the code is fairly mature at this point
957 // and we're betting that the access order won't change much.)
958
959 MarkAndMoveOrderedReadOnly mark_and_move_ordered_ro(&move_ro);
960 MarkAndMoveOrderedReadWrite mark_and_move_ordered_rw(&move_rw);
961
962 // Phase 1a: move commonly used read-only objects to the read-only space.
963
964 if (SharedOptimizeColdStart) {
965 tty->print("Moving pre-ordered read-only objects to shared space at " PTR_FORMAT " ... ",
966 _ro_space->top());
967 for (int i = 0; i < _class_promote_order->length(); i++) {
968 oop obj = _class_promote_order->at(i);
969 mark_and_move_ordered_ro.do_object(obj);
970 }
971 tty->print_cr("done. ");
972 }
973
974 tty->print("Moving read-only objects to shared space at " PTR_FORMAT " ... ",
975 _ro_space->top());
976 gch->object_iterate(&mark_common_ro);
977 gch->object_iterate(&move_ro);
978 tty->print_cr("done. ");
979
980 // Phase 1b: move commonly used symbols to the read-only space.
981
982 tty->print("Moving common symbols to shared space at " PTR_FORMAT " ... ",
983 _ro_space->top());
984 gch->object_iterate(&mark_common_symbols);
985 gch->object_iterate(&move_ro);
986 tty->print_cr("done. ");
987
988 // Phase 1c: move remaining symbols to the read-only space
989 // (e.g. String initializers).
990
991 tty->print("Moving remaining symbols to shared space at " PTR_FORMAT " ... ",
992 _ro_space->top());
993 vmSymbols::oops_do(&mark_all, true);
994 gch->object_iterate(&move_ro);
995 tty->print_cr("done. ");
996
997 // Phase 1d: move String character arrays to the read-only space.
998
999 tty->print("Moving string char arrays to shared space at " PTR_FORMAT " ... ",
1000 _ro_space->top());
1001 gch->object_iterate(&mark_string_values);
1002 gch->object_iterate(&move_ro);
1003 tty->print_cr("done. ");
1004
1005 // Phase 2: move all remaining symbols to the read-only space. The
1006 // remaining symbols are assumed to be string initializers no longer
1007 // referenced.
1008
1009 void* extra_symbols = _ro_space->top();
1010 tty->print("Moving additional symbols to shared space at " PTR_FORMAT " ... ",
1011 _ro_space->top());
1012 SymbolTable::oops_do(&mark_all);
1013 gch->object_iterate(&move_ro);
1014 tty->print_cr("done. ");
1015 tty->print_cr("Read-only space ends at " PTR_FORMAT ", %d bytes.",
1016 _ro_space->top(), _ro_space->used());
1017
1018 // Phase 3: move read-write objects to the read-write space, except
1019 // Strings.
1020
1021 if (SharedOptimizeColdStart) {
1022 tty->print("Moving pre-ordered read-write objects to shared space at " PTR_FORMAT " ... ",
1023 _rw_space->top());
1024 for (int i = 0; i < _class_promote_order->length(); i++) {
1025 oop obj = _class_promote_order->at(i);
1026 mark_and_move_ordered_rw.do_object(obj);
1027 }
1028 tty->print_cr("done. ");
1029 }
1030 tty->print("Moving read-write objects to shared space at " PTR_FORMAT " ... ",
1031 _rw_space->top());
1032 Universe::oops_do(&mark_all, true);
1033 SystemDictionary::oops_do(&mark_all);
1034 oop tmp = Universe::arithmetic_exception_instance();
1035 mark_object(java_lang_Throwable::message(tmp));
1036 gch->object_iterate(&mark_rw);
1037 gch->object_iterate(&move_rw);
1038 tty->print_cr("done. ");
1039
1040 // Phase 4: move String objects to the read-write space.
1041
1042 tty->print("Moving String objects to shared space at " PTR_FORMAT " ... ",
1043 _rw_space->top());
1044 StringTable::oops_do(&mark_all);
1045 gch->object_iterate(&mark_strings);
1046 gch->object_iterate(&move_rw);
1047 tty->print_cr("done. ");
1048 tty->print_cr("Read-write space ends at " PTR_FORMAT ", %d bytes.",
1049 _rw_space->top(), _rw_space->used());
1050
1051 #ifdef DEBUG
1052 // Check: scan for objects which were not moved.
1053
1054 CheckRemainingObjects check_objects;
1055 gch->object_iterate(&check_objects);
1056 check_objects.status();
1057 #endif
1058
1059 // Resolve forwarding in objects and saved C++ structures
1060 tty->print("Updating references to shared objects ... ");
1061 ResolveForwardingClosure resolve;
1062 Universe::oops_do(&resolve);
1063 SystemDictionary::oops_do(&resolve);
1064 StringTable::oops_do(&resolve);
1065 SymbolTable::oops_do(&resolve);
1066 vmSymbols::oops_do(&resolve);
1067
1068 // Set up the share data and shared code segments.
1069
1070 char* md_top = _md_vs->low();
1071 char* md_end = _md_vs->high();
1072 char* mc_top = _mc_vs->low();
1073 char* mc_end = _mc_vs->high();
1074
1075 // Reserve space for the list of klassOops whose vtables are used
1076 // for patching others as needed.
1077
1078 void** vtbl_list = (void**)md_top;
1079 int vtbl_list_size = CompactingPermGenGen::vtbl_list_size;
1080 Universe::init_self_patching_vtbl_list(vtbl_list, vtbl_list_size);
1081
1082 md_top += vtbl_list_size * sizeof(void*);
1083 void* vtable = md_top;
1084
1085 // Reserve space for a new dummy vtable for klass objects in the
1086 // heap. Generate self-patching vtable entries.
1087
1088 CompactingPermGenGen::generate_vtable_methods(vtbl_list,
1089 &vtable,
1090 &md_top, md_end,
1091 &mc_top, mc_end);
1092
1093 // Fix (forward) all of the references in these shared objects (which
1094 // are required to point ONLY to objects in the shared spaces).
1095 // Also, create a list of all objects which might later contain a
1096 // reference to a younger generation object.
1097
1098 CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen();
1099 PatchOopsClosure patch(THREAD);
1100 gen->ro_space()->object_iterate(&patch);
1101 gen->rw_space()->object_iterate(&patch);
1102
1103 // Previously method sorting was done concurrently with forwarding
1104 // pointer resolution in the shared spaces. This imposed an ordering
1105 // restriction in that methods were required to be promoted/patched
1106 // before their holder classes. (Because constant pool pointers in
1107 // methodKlasses are required to be resolved before their holder class
1108 // is visited for sorting, otherwise methods are sorted by incorrect,
1109 // pre-forwarding addresses.)
1110 //
1111 // Now, we reorder methods as a separate step after ALL forwarding
1112 // pointer resolution, so that methods can be promoted in any order
1113 // with respect to their holder classes.
1114
1115 SortMethodsClosure sort(THREAD);
1116 gen->ro_space()->object_iterate(&sort);
1117 gen->rw_space()->object_iterate(&sort);
1118 tty->print_cr("done. ");
1119 tty->cr();
1120
1121 // Reorder the system dictionary. (Moving the symbols opps affects
1122 // how the hash table indices are calculated.)
1123
1124 SystemDictionary::reorder_dictionary();
1125
1126 // Empty the non-shared heap (because most of the objects were
1127 // copied out, and the remainder cannot be considered valid oops).
1128
1129 ClearSpaceClosure csc;
1130 for (int i = 0; i < gch->n_gens(); ++i) {
1131 gch->get_gen(i)->space_iterate(&csc);
1132 }
1133 csc.do_space(gen->the_space());
1134 NOT_PRODUCT(SystemDictionary::verify();)
1135
1136 // Copy the String table, the symbol table, and the system
1137 // dictionary to the shared space in usable form. Copy the hastable
1138 // buckets first [read-write], then copy the linked lists of entries
1139 // [read-only].
1140
1141 SymbolTable::reverse(extra_symbols);
1142 NOT_PRODUCT(SymbolTable::verify());
1143 SymbolTable::copy_buckets(&md_top, md_end);
1144
1145 StringTable::reverse();
1146 NOT_PRODUCT(StringTable::verify());
1147 StringTable::copy_buckets(&md_top, md_end);
1148
1149 SystemDictionary::reverse();
1150 SystemDictionary::copy_buckets(&md_top, md_end);
1151
1152 ClassLoader::verify();
1153 ClassLoader::copy_package_info_buckets(&md_top, md_end);
1154 ClassLoader::verify();
1155
1156 SymbolTable::copy_table(&md_top, md_end);
1157 StringTable::copy_table(&md_top, md_end);
1158 SystemDictionary::copy_table(&md_top, md_end);
1159 ClassLoader::verify();
1160 ClassLoader::copy_package_info_table(&md_top, md_end);
1161 ClassLoader::verify();
1162
1163 // Print debug data.
1164
1165 if (PrintSharedSpaces) {
1166 const char* fmt = "%s space: " PTR_FORMAT " out of " PTR_FORMAT " bytes allocated at " PTR_FORMAT ".";
1167 tty->print_cr(fmt, "ro", _ro_space->used(), _ro_space->capacity(),
1168 _ro_space->bottom());
1169 tty->print_cr(fmt, "rw", _rw_space->used(), _rw_space->capacity(),
1170 _rw_space->bottom());
1171 }
1172
1173 // Write the oop data to the output array.
1174
1175 WriteClosure wc(md_top, md_end);
1176 CompactingPermGenGen::serialize_oops(&wc);
1177 md_top = wc.get_top();
1178
1179 // Update the vtable pointers in all of the Klass objects in the
1180 // heap. They should point to newly generated vtable.
1181
1182 PatchKlassVtables pkvt(vtable, _md_vs);
1183 _rw_space->object_iterate(&pkvt);
1184 pkvt.patch(vtbl_list, vtbl_list_size);
1185
1186 char* saved_vtbl = (char*)malloc(vtbl_list_size * sizeof(void*));
1187 memmove(saved_vtbl, vtbl_list, vtbl_list_size * sizeof(void*));
1188 memset(vtbl_list, 0, vtbl_list_size * sizeof(void*));
1189
1190 // Create and write the archive file that maps the shared spaces.
1191
1192 FileMapInfo* mapinfo = new FileMapInfo();
1193 mapinfo->populate_header(gch->gen_policy()->max_alignment());
1194
1195 // Pass 1 - update file offsets in header.
1196 mapinfo->write_header();
1197 mapinfo->write_space(CompactingPermGenGen::ro, _ro_space, true);
1198 _ro_space->set_saved_mark();
1199 mapinfo->write_space(CompactingPermGenGen::rw, _rw_space, false);
1200 _rw_space->set_saved_mark();
1201 mapinfo->write_region(CompactingPermGenGen::md, _md_vs->low(),
1202 md_top - _md_vs->low(), SharedMiscDataSize,
1203 false, false);
1204 mapinfo->write_region(CompactingPermGenGen::mc, _mc_vs->low(),
1205 mc_top - _mc_vs->low(), SharedMiscCodeSize,
1206 true, true);
1207
1208 // Pass 2 - write data.
1209 mapinfo->open_for_write();
1210 mapinfo->write_header();
1211 mapinfo->write_space(CompactingPermGenGen::ro, _ro_space, true);
1212 mapinfo->write_space(CompactingPermGenGen::rw, _rw_space, false);
1213 mapinfo->write_region(CompactingPermGenGen::md, _md_vs->low(),
1214 md_top - _md_vs->low(), SharedMiscDataSize,
1215 false, false);
1216 mapinfo->write_region(CompactingPermGenGen::mc, _mc_vs->low(),
1217 mc_top - _mc_vs->low(), SharedMiscCodeSize,
1218 true, true);
1219 mapinfo->close();
1220
1221 // Summarize heap.
1222 memmove(vtbl_list, saved_vtbl, vtbl_list_size * sizeof(void*));
1223 print_contents();
1224 }
1225 }; // class VM_PopulateDumpSharedSpace
1226
1227
1228 // Populate the shared spaces and dump to a file.
1229
1230 jint CompactingPermGenGen::dump_shared(GrowableArray<oop>* class_promote_order, TRAPS) {
1231 GenCollectedHeap* gch = GenCollectedHeap::heap();
1232
1233 // Calculate hash values for all of the (interned) strings to avoid
1234 // writes to shared pages in the future.
1235
1236 tty->print("Calculating hash values for String objects .. ");
1237 StringHashCodeClosure shcc(THREAD);
1238 StringTable::oops_do(&shcc);
1239 tty->print_cr("done. ");
1240
1241 CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen();
1242 VM_PopulateDumpSharedSpace op(class_promote_order,
1243 gen->ro_space(), gen->rw_space(),
1244 gen->md_space(), gen->mc_space());
1245 VMThread::execute(&op);
1246 return JNI_OK;
1247 }
1248
1249
1250 class LinkClassesClosure : public ObjectClosure {
1251 private:
1252 Thread* THREAD;
1253
1254 public:
1255 LinkClassesClosure(Thread* thread) : THREAD(thread) {}
1256
1257 void do_object(oop obj) {
1258 if (obj->is_klass()) {
1259 Klass* k = Klass::cast((klassOop) obj);
1260 if (k->oop_is_instance()) {
1261 instanceKlass* ik = (instanceKlass*) k;
1262 // Link the class to cause the bytecodes to be rewritten and the
1263 // cpcache to be created.
1264 if (ik->get_init_state() < instanceKlass::linked) {
1265 ik->link_class(THREAD);
1266 guarantee(!HAS_PENDING_EXCEPTION, "exception in class rewriting");
1267 }
1268
1269 // Create String objects from string initializer symbols.
1270 ik->constants()->resolve_string_constants(THREAD);
1271 guarantee(!HAS_PENDING_EXCEPTION, "exception resolving string constants");
1272 }
1273 }
1274 }
1275 };
1276
1277
1278 // Support for a simple checksum of the contents of the class list
1279 // file to prevent trivial tampering. The algorithm matches that in
1280 // the MakeClassList program used by the J2SE build process.
1281 #define JSUM_SEED ((jlong)CONST64(0xcafebabebabecafe))
1282 static jlong
1283 jsum(jlong start, const char *buf, const int len)
1284 {
1285 jlong h = start;
1286 char *p = (char *)buf, *e = p + len;
1287 while (p < e) {
1288 char c = *p++;
1289 if (c <= ' ') {
1290 /* Skip spaces and control characters */
1291 continue;
1292 }
1293 h = 31 * h + c;
1294 }
1295 return h;
1296 }
1297
1298
1299
1300
1301
1302 // Preload classes from a list, populate the shared spaces and dump to a
1303 // file.
1304
1305 void GenCollectedHeap::preload_and_dump(TRAPS) {
1306 TraceTime timer("Dump Shared Spaces", TraceStartupTime);
1307 ResourceMark rm;
1308
1309 // Preload classes to be shared.
1310 // Should use some hpi:: method rather than fopen() here. aB.
1311 // Construct the path to the class list (in jre/lib)
1312 // Walk up two directories from the location of the VM and
1313 // optionally tack on "lib" (depending on platform)
1314 char class_list_path[JVM_MAXPATHLEN];
1315 os::jvm_path(class_list_path, sizeof(class_list_path));
1316 for (int i = 0; i < 3; i++) {
1317 char *end = strrchr(class_list_path, *os::file_separator());
1318 if (end != NULL) *end = '\0';
1319 }
1320 int class_list_path_len = (int)strlen(class_list_path);
1321 if (class_list_path_len >= 3) {
1322 if (strcmp(class_list_path + class_list_path_len - 3, "lib") != 0) {
1323 strcat(class_list_path, os::file_separator());
1324 strcat(class_list_path, "lib");
1325 }
1326 }
1327 strcat(class_list_path, os::file_separator());
1328 strcat(class_list_path, "classlist");
1329
1330 FILE* file = fopen(class_list_path, "r");
1331 if (file != NULL) {
1332 jlong computed_jsum = JSUM_SEED;
1333 jlong file_jsum = 0;
1334
1335 char class_name[256];
1336 int class_count = 0;
1337 GenCollectedHeap* gch = GenCollectedHeap::heap();
1338 gch->_preloading_shared_classes = true;
1339 GrowableArray<oop>* class_promote_order = new GrowableArray<oop>();
1340
1341 // Preload (and intern) strings which will be used later.
1342
1343 StringTable::intern("main", THREAD);
1344 StringTable::intern("([Ljava/lang/String;)V", THREAD);
1345 StringTable::intern("Ljava/lang/Class;", THREAD);
1346
1347 StringTable::intern("I", THREAD); // Needed for StringBuffer persistence?
1348 StringTable::intern("Z", THREAD); // Needed for StringBuffer persistence?
1349
1350 // sun.io.Converters
1351 static const char obj_array_sig[] = "[[Ljava/lang/Object;";
1352 SymbolTable::lookup(obj_array_sig, (int)strlen(obj_array_sig), THREAD);
1353
1354 // java.util.HashMap
1355 static const char map_entry_array_sig[] = "[Ljava/util/Map$Entry;";
1356 SymbolTable::lookup(map_entry_array_sig, (int)strlen(map_entry_array_sig),
1357 THREAD);
1358
1359 tty->print("Loading classes to share ... ");
1360 while ((fgets(class_name, sizeof class_name, file)) != NULL) {
1361 if (*class_name == '#') {
1362 jint fsh, fsl;
1363 if (sscanf(class_name, "# %8x%8x\n", &fsh, &fsl) == 2) {
1364 file_jsum = ((jlong)(fsh) << 32) | (fsl & 0xffffffff);
1365 }
1366
1367 continue;
1368 }
1369 // Remove trailing newline
1370 size_t name_len = strlen(class_name);
1371 class_name[name_len-1] = '\0';
1372
1373 computed_jsum = jsum(computed_jsum, class_name, (const int)name_len - 1);
1374
1375 // Got a class name - load it.
1376 symbolHandle class_name_symbol = oopFactory::new_symbol(class_name,
1377 THREAD);
1378 guarantee(!HAS_PENDING_EXCEPTION, "Exception creating a symbol.");
1379 klassOop klass = SystemDictionary::resolve_or_null(class_name_symbol,
1380 THREAD);
1381 guarantee(!HAS_PENDING_EXCEPTION, "Exception resolving a class.");
1382 if (klass != NULL) {
1383 if (PrintSharedSpaces) {
1384 tty->print_cr("Shared spaces preloaded: %s", class_name);
1385 }
1386
1387
1388 instanceKlass* ik = instanceKlass::cast(klass);
1389
1390 // Should be class load order as per -XX:+TraceClassLoadingPreorder
1391 class_promote_order->append(ik->as_klassOop());
1392
1393 // Link the class to cause the bytecodes to be rewritten and the
1394 // cpcache to be created. The linking is done as soon as classes
1395 // are loaded in order that the related data structures (klass,
1396 // cpCache, Sting constants) are located together.
1397
1398 if (ik->get_init_state() < instanceKlass::linked) {
1399 ik->link_class(THREAD);
1400 guarantee(!(HAS_PENDING_EXCEPTION), "exception in class rewriting");
1401 }
1402
1403 // Create String objects from string initializer symbols.
1404
1405 ik->constants()->resolve_string_constants(THREAD);
1406
1407 class_count++;
1408 } else {
1409 if (PrintSharedSpaces) {
1410 tty->cr();
1411 tty->print_cr(" Preload failed: %s", class_name);
1412 }
1413 }
1414 file_jsum = 0; // Checksum must be on last line of file
1415 }
1416 if (computed_jsum != file_jsum) {
1417 tty->cr();
1418 tty->print_cr("Preload failed: checksum of class list was incorrect.");
1419 exit(1);
1420 }
1421
1422 tty->print_cr("done. ");
1423
1424 if (PrintSharedSpaces) {
1425 tty->print_cr("Shared spaces: preloaded %d classes", class_count);
1426 }
1427
1428 // Rewrite and unlink classes.
1429 tty->print("Rewriting and unlinking classes ... ");
1430 // Make heap parsable
1431 ensure_parsability(false); // arg is actually don't care
1432
1433 // Link any classes which got missed. (It's not quite clear why
1434 // they got missed.) This iteration would be unsafe if we weren't
1435 // single-threaded at this point; however we can't do it on the VM
1436 // thread because it requires object allocation.
1437 LinkClassesClosure lcc(Thread::current());
1438 object_iterate(&lcc);
1439 tty->print_cr("done. ");
1440
1441 // Create and dump the shared spaces.
1442 jint err = CompactingPermGenGen::dump_shared(class_promote_order, THREAD);
1443 if (err != JNI_OK) {
1444 fatal("Dumping shared spaces failed.");
1445 }
1446
1447 } else {
1448 char errmsg[JVM_MAXPATHLEN];
1449 hpi::lasterror(errmsg, JVM_MAXPATHLEN);
1450 tty->print_cr("Loading classlist failed: %s", errmsg);
1451 exit(1);
1452 }
1453
1454 // Since various initialization steps have been undone by this process,
1455 // it is not reasonable to continue running a java process.
1456 exit(0);
1457 }