1 /*
2 * Copyright (c) 1997, 2009, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "incls/_precompiled.incl"
26 #include "incls/_klassVtable.cpp.incl"
27
28 inline instanceKlass* klassVtable::ik() const {
29 Klass* k = _klass()->klass_part();
30 assert(k->oop_is_instance(), "not an instanceKlass");
31 return (instanceKlass*)k;
32 }
33
34
35 // this function computes the vtable size (including the size needed for miranda
36 // methods) and the number of miranda methods in this class
37 // Note on Miranda methods: Let's say there is a class C that implements
38 // interface I. Let's say there is a method m in I that neither C nor any
39 // of its super classes implement (i.e there is no method of any access, with
40 // the same name and signature as m), then m is a Miranda method which is
41 // entered as a public abstract method in C's vtable. From then on it should
42 // treated as any other public method in C for method over-ride purposes.
43 void klassVtable::compute_vtable_size_and_num_mirandas(int &vtable_length,
44 int &num_miranda_methods,
45 klassOop super,
46 objArrayOop methods,
47 AccessFlags class_flags,
48 Handle classloader,
49 symbolHandle classname,
50 objArrayOop local_interfaces,
51 TRAPS
52 ) {
53
54 No_Safepoint_Verifier nsv;
55
56 // set up default result values
57 vtable_length = 0;
58 num_miranda_methods = 0;
59
60 // start off with super's vtable length
61 instanceKlass* sk = (instanceKlass*)super->klass_part();
62 vtable_length = super == NULL ? 0 : sk->vtable_length();
63
64 // go thru each method in the methods table to see if it needs a new entry
65 int len = methods->length();
66 for (int i = 0; i < len; i++) {
67 assert(methods->obj_at(i)->is_method(), "must be a methodOop");
68 methodHandle mh(THREAD, methodOop(methods->obj_at(i)));
69
70 if (needs_new_vtable_entry(mh, super, classloader, classname, class_flags, THREAD)) {
71 vtable_length += vtableEntry::size(); // we need a new entry
72 }
73 }
74
75 // compute the number of mirandas methods that must be added to the end
76 num_miranda_methods = get_num_mirandas(super, methods, local_interfaces);
77 vtable_length += (num_miranda_methods * vtableEntry::size());
78
79 if (Universe::is_bootstrapping() && vtable_length == 0) {
80 // array classes don't have their superclass set correctly during
81 // bootstrapping
82 vtable_length = Universe::base_vtable_size();
83 }
84
85 if (super == NULL && !Universe::is_bootstrapping() &&
86 vtable_length != Universe::base_vtable_size()) {
87 // Someone is attempting to redefine java.lang.Object incorrectly. The
88 // only way this should happen is from
89 // SystemDictionary::resolve_from_stream(), which will detect this later
90 // and throw a security exception. So don't assert here to let
91 // the exception occur.
92 vtable_length = Universe::base_vtable_size();
93 }
94 assert(super != NULL || vtable_length == Universe::base_vtable_size(),
95 "bad vtable size for class Object");
96 assert(vtable_length % vtableEntry::size() == 0, "bad vtable length");
97 assert(vtable_length >= Universe::base_vtable_size(), "vtable too small");
98 }
99
100 int klassVtable::index_of(methodOop m, int len) const {
101 assert(m->vtable_index() >= 0, "do not ask this of non-vtable methods");
102 return m->vtable_index();
103 }
104
105 int klassVtable::initialize_from_super(KlassHandle super) {
106 if (super.is_null()) {
107 return 0;
108 } else {
109 // copy methods from superKlass
110 // can't inherit from array class, so must be instanceKlass
111 assert(super->oop_is_instance(), "must be instance klass");
112 instanceKlass* sk = (instanceKlass*)super()->klass_part();
113 klassVtable* superVtable = sk->vtable();
114 assert(superVtable->length() <= _length, "vtable too short");
115 #ifdef ASSERT
116 superVtable->verify(tty, true);
117 #endif
118 superVtable->copy_vtable_to(table());
119 #ifndef PRODUCT
120 if (PrintVtables && Verbose) {
121 ResourceMark rm;
122 tty->print_cr("copy vtable from %s to %s size %d", sk->internal_name(), klass()->internal_name(), _length);
123 }
124 #endif
125 return superVtable->length();
126 }
127 }
128
129 // Revised lookup semantics introduced 1.3 (Kestral beta)
130 void klassVtable::initialize_vtable(bool checkconstraints, TRAPS) {
131
132 // Note: Arrays can have intermediate array supers. Use java_super to skip them.
133 KlassHandle super (THREAD, klass()->java_super());
134 int nofNewEntries = 0;
135
136
137 if (PrintVtables && !klass()->oop_is_array()) {
138 ResourceMark rm(THREAD);
139 tty->print_cr("Initializing: %s", _klass->name()->as_C_string());
140 }
141
142 #ifdef ASSERT
143 oop* end_of_obj = (oop*)_klass() + _klass()->size();
144 oop* end_of_vtable = (oop*)&table()[_length];
145 assert(end_of_vtable <= end_of_obj, "vtable extends beyond end");
146 #endif
147
148 if (Universe::is_bootstrapping()) {
149 // just clear everything
150 for (int i = 0; i < _length; i++) table()[i].clear();
151 return;
152 }
153
154 int super_vtable_len = initialize_from_super(super);
155 if (klass()->oop_is_array()) {
156 assert(super_vtable_len == _length, "arrays shouldn't introduce new methods");
157 } else {
158 assert(_klass->oop_is_instance(), "must be instanceKlass");
159
160 objArrayHandle methods(THREAD, ik()->methods());
161 int len = methods()->length();
162 int initialized = super_vtable_len;
163
164 // update_inherited_vtable can stop for gc - ensure using handles
165 for (int i = 0; i < len; i++) {
166 HandleMark hm(THREAD);
167 assert(methods()->obj_at(i)->is_method(), "must be a methodOop");
168 methodHandle mh(THREAD, (methodOop)methods()->obj_at(i));
169
170 bool needs_new_entry = update_inherited_vtable(ik(), mh, super_vtable_len, checkconstraints, CHECK);
171
172 if (needs_new_entry) {
173 put_method_at(mh(), initialized);
174 mh()->set_vtable_index(initialized); // set primary vtable index
175 initialized++;
176 }
177 }
178
179 // add miranda methods; it will also update the value of initialized
180 fill_in_mirandas(initialized);
181
182 // In class hierarchies where the accessibility is not increasing (i.e., going from private ->
183 // package_private -> publicprotected), the vtable might actually be smaller than our initial
184 // calculation.
185 assert(initialized <= _length, "vtable initialization failed");
186 for(;initialized < _length; initialized++) {
187 put_method_at(NULL, initialized);
188 }
189 NOT_PRODUCT(verify(tty, true));
190 }
191 }
192
193 // Called for cases where a method does not override its superclass' vtable entry
194 // For bytecodes not produced by javac together it is possible that a method does not override
195 // the superclass's method, but might indirectly override a super-super class's vtable entry
196 // If none found, return a null superk, else return the superk of the method this does override
197 instanceKlass* klassVtable::find_transitive_override(instanceKlass* initialsuper, methodHandle target_method,
198 int vtable_index, Handle target_loader, symbolHandle target_classname, Thread * THREAD) {
199 instanceKlass* superk = initialsuper;
200 while (superk != NULL && superk->super() != NULL) {
201 instanceKlass* supersuperklass = instanceKlass::cast(superk->super());
202 klassVtable* ssVtable = supersuperklass->vtable();
203 if (vtable_index < ssVtable->length()) {
204 methodOop super_method = ssVtable->method_at(vtable_index);
205 #ifndef PRODUCT
206 symbolHandle name(THREAD,target_method()->name());
207 symbolHandle signature(THREAD,target_method()->signature());
208 assert(super_method->name() == name() && super_method->signature() == signature(), "vtable entry name/sig mismatch");
209 #endif
210 if (supersuperklass->is_override(super_method, target_loader, target_classname, THREAD)) {
211 #ifndef PRODUCT
212 if (PrintVtables && Verbose) {
213 ResourceMark rm(THREAD);
214 tty->print("transitive overriding superclass %s with %s::%s index %d, original flags: ",
215 supersuperklass->internal_name(),
216 _klass->internal_name(), (target_method() != NULL) ?
217 target_method()->name()->as_C_string() : "<NULL>", vtable_index);
218 super_method->access_flags().print_on(tty);
219 tty->print("overriders flags: ");
220 target_method->access_flags().print_on(tty);
221 tty->cr();
222 }
223 #endif /*PRODUCT*/
224 break; // return found superk
225 }
226 } else {
227 // super class has no vtable entry here, stop transitive search
228 superk = (instanceKlass*)NULL;
229 break;
230 }
231 // if no override found yet, continue to search up
232 superk = instanceKlass::cast(superk->super());
233 }
234
235 return superk;
236 }
237
238
239 // Update child's copy of super vtable for overrides
240 // OR return true if a new vtable entry is required
241 // Only called for instanceKlass's, i.e. not for arrays
242 // If that changed, could not use _klass as handle for klass
243 bool klassVtable::update_inherited_vtable(instanceKlass* klass, methodHandle target_method, int super_vtable_len,
244 bool checkconstraints, TRAPS) {
245 ResourceMark rm;
246 bool allocate_new = true;
247 assert(klass->oop_is_instance(), "must be instanceKlass");
248
249 // Initialize the method's vtable index to "nonvirtual".
250 // If we allocate a vtable entry, we will update it to a non-negative number.
251 target_method()->set_vtable_index(methodOopDesc::nonvirtual_vtable_index);
252
253 // Static and <init> methods are never in
254 if (target_method()->is_static() || target_method()->name() == vmSymbols::object_initializer_name()) {
255 return false;
256 }
257
258 if (klass->is_final() || target_method()->is_final()) {
259 // a final method never needs a new entry; final methods can be statically
260 // resolved and they have to be present in the vtable only if they override
261 // a super's method, in which case they re-use its entry
262 allocate_new = false;
263 }
264
265 // we need a new entry if there is no superclass
266 if (klass->super() == NULL) {
267 return allocate_new;
268 }
269
270 // private methods always have a new entry in the vtable
271 // specification interpretation since classic has
272 // private methods not overriding
273 if (target_method()->is_private()) {
274 return allocate_new;
275 }
276
277 // search through the vtable and update overridden entries
278 // Since check_signature_loaders acquires SystemDictionary_lock
279 // which can block for gc, once we are in this loop, use handles
280 // For classfiles built with >= jdk7, we now look for transitive overrides
281
282 symbolHandle name(THREAD,target_method()->name());
283 symbolHandle signature(THREAD,target_method()->signature());
284 Handle target_loader(THREAD, _klass->class_loader());
285 symbolHandle target_classname(THREAD, _klass->name());
286 for(int i = 0; i < super_vtable_len; i++) {
287 methodOop super_method = method_at(i);
288 // Check if method name matches
289 if (super_method->name() == name() && super_method->signature() == signature()) {
290
291 // get super_klass for method_holder for the found method
292 instanceKlass* super_klass = instanceKlass::cast(super_method->method_holder());
293
294 if ((super_klass->is_override(super_method, target_loader, target_classname, THREAD)) ||
295 ((klass->major_version() >= VTABLE_TRANSITIVE_OVERRIDE_VERSION)
296 && ((super_klass = find_transitive_override(super_klass, target_method, i, target_loader,
297 target_classname, THREAD)) != (instanceKlass*)NULL))) {
298 // overriding, so no new entry
299 allocate_new = false;
300
301 if (checkconstraints) {
302 // Override vtable entry if passes loader constraint check
303 // if loader constraint checking requested
304 // No need to visit his super, since he and his super
305 // have already made any needed loader constraints.
306 // Since loader constraints are transitive, it is enough
307 // to link to the first super, and we get all the others.
308 Handle super_loader(THREAD, super_klass->class_loader());
309
310 if (target_loader() != super_loader()) {
311 ResourceMark rm(THREAD);
312 char* failed_type_name =
313 SystemDictionary::check_signature_loaders(signature, target_loader,
314 super_loader, true,
315 CHECK_(false));
316 if (failed_type_name != NULL) {
317 const char* msg = "loader constraint violation: when resolving "
318 "overridden method \"%s\" the class loader (instance"
319 " of %s) of the current class, %s, and its superclass loader "
320 "(instance of %s), have different Class objects for the type "
321 "%s used in the signature";
322 char* sig = target_method()->name_and_sig_as_C_string();
323 const char* loader1 = SystemDictionary::loader_name(target_loader());
324 char* current = _klass->name()->as_C_string();
325 const char* loader2 = SystemDictionary::loader_name(super_loader());
326 size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) +
327 strlen(current) + strlen(loader2) + strlen(failed_type_name);
328 char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
329 jio_snprintf(buf, buflen, msg, sig, loader1, current, loader2,
330 failed_type_name);
331 THROW_MSG_(vmSymbols::java_lang_LinkageError(), buf, false);
332 }
333 }
334 }
335
336 put_method_at(target_method(), i);
337 target_method()->set_vtable_index(i);
338 #ifndef PRODUCT
339 if (PrintVtables && Verbose) {
340 tty->print("overriding with %s::%s index %d, original flags: ",
341 _klass->internal_name(), (target_method() != NULL) ?
342 target_method()->name()->as_C_string() : "<NULL>", i);
343 super_method->access_flags().print_on(tty);
344 tty->print("overriders flags: ");
345 target_method->access_flags().print_on(tty);
346 tty->cr();
347 }
348 #endif /*PRODUCT*/
349 } else {
350 // allocate_new = true; default. We might override one entry,
351 // but not override another. Once we override one, not need new
352 #ifndef PRODUCT
353 if (PrintVtables && Verbose) {
354 tty->print("NOT overriding with %s::%s index %d, original flags: ",
355 _klass->internal_name(), (target_method() != NULL) ?
356 target_method()->name()->as_C_string() : "<NULL>", i);
357 super_method->access_flags().print_on(tty);
358 tty->print("overriders flags: ");
359 target_method->access_flags().print_on(tty);
360 tty->cr();
361 }
362 #endif /*PRODUCT*/
363 }
364 }
365 }
366 return allocate_new;
367 }
368
369 void klassVtable::put_method_at(methodOop m, int index) {
370 assert(m->is_oop_or_null(), "Not an oop or null");
371 #ifndef PRODUCT
372 if (PrintVtables && Verbose) {
373 ResourceMark rm;
374 tty->print_cr("adding %s::%s at index %d", _klass->internal_name(),
375 (m != NULL) ? m->name()->as_C_string() : "<NULL>", index);
376 }
377 assert(unchecked_method_at(index)->is_oop_or_null(), "Not an oop or null");
378 #endif
379 table()[index].set(m);
380 }
381
382 // Find out if a method "m" with superclass "super", loader "classloader" and
383 // name "classname" needs a new vtable entry. Let P be a class package defined
384 // by "classloader" and "classname".
385 // NOTE: The logic used here is very similar to the one used for computing
386 // the vtables indices for a method. We cannot directly use that function because,
387 // we allocate the instanceKlass at load time, and that requires that the
388 // superclass has been loaded.
389 // However, the vtable entries are filled in at link time, and therefore
390 // the superclass' vtable may not yet have been filled in.
391 bool klassVtable::needs_new_vtable_entry(methodHandle target_method,
392 klassOop super,
393 Handle classloader,
394 symbolHandle classname,
395 AccessFlags class_flags,
396 TRAPS) {
397 if ((class_flags.is_final() || target_method()->is_final()) ||
398 // a final method never needs a new entry; final methods can be statically
399 // resolved and they have to be present in the vtable only if they override
400 // a super's method, in which case they re-use its entry
401 (target_method()->is_static()) ||
402 // static methods don't need to be in vtable
403 (target_method()->name() == vmSymbols::object_initializer_name())
404 // <init> is never called dynamically-bound
405 ) {
406 return false;
407 }
408
409 // we need a new entry if there is no superclass
410 if (super == NULL) {
411 return true;
412 }
413
414 // private methods always have a new entry in the vtable
415 // specification interpretation since classic has
416 // private methods not overriding
417 if (target_method()->is_private()) {
418 return true;
419 }
420
421 // search through the super class hierarchy to see if we need
422 // a new entry
423 ResourceMark rm;
424 symbolOop name = target_method()->name();
425 symbolOop signature = target_method()->signature();
426 klassOop k = super;
427 methodOop super_method = NULL;
428 instanceKlass *holder = NULL;
429 methodOop recheck_method = NULL;
430 while (k != NULL) {
431 // lookup through the hierarchy for a method with matching name and sign.
432 super_method = instanceKlass::cast(k)->lookup_method(name, signature);
433 if (super_method == NULL) {
434 break; // we still have to search for a matching miranda method
435 }
436 // get the class holding the matching method
437 // make sure you use that class for is_override
438 instanceKlass* superk = instanceKlass::cast(super_method->method_holder());
439 // we want only instance method matches
440 // pretend private methods are not in the super vtable
441 // since we do override around them: e.g. a.m pub/b.m private/c.m pub,
442 // ignore private, c.m pub does override a.m pub
443 // For classes that were not javac'd together, we also do transitive overriding around
444 // methods that have less accessibility
445 if ((!super_method->is_static()) &&
446 (!super_method->is_private())) {
447 if (superk->is_override(super_method, classloader, classname, THREAD)) {
448 return false;
449 // else keep looking for transitive overrides
450 }
451 }
452
453 // Start with lookup result and continue to search up
454 k = superk->super(); // haven't found an override match yet; continue to look
455 }
456
457 // if the target method is public or protected it may have a matching
458 // miranda method in the super, whose entry it should re-use.
459 // Actually, to handle cases that javac would not generate, we need
460 // this check for all access permissions.
461 instanceKlass *sk = instanceKlass::cast(super);
462 if (sk->has_miranda_methods()) {
463 if (sk->lookup_method_in_all_interfaces(name, signature) != NULL) {
464 return false; // found a matching miranda; we do not need a new entry
465 }
466 }
467 return true; // found no match; we need a new entry
468 }
469
470 // Support for miranda methods
471
472 // get the vtable index of a miranda method with matching "name" and "signature"
473 int klassVtable::index_of_miranda(symbolOop name, symbolOop signature) {
474 // search from the bottom, might be faster
475 for (int i = (length() - 1); i >= 0; i--) {
476 methodOop m = table()[i].method();
477 if (is_miranda_entry_at(i) &&
478 m->name() == name && m->signature() == signature) {
479 return i;
480 }
481 }
482 return methodOopDesc::invalid_vtable_index;
483 }
484
485 // check if an entry is miranda
486 bool klassVtable::is_miranda_entry_at(int i) {
487 methodOop m = method_at(i);
488 klassOop method_holder = m->method_holder();
489 instanceKlass *mhk = instanceKlass::cast(method_holder);
490
491 // miranda methods are interface methods in a class's vtable
492 if (mhk->is_interface()) {
493 assert(m->is_public() && m->is_abstract(), "should be public and abstract");
494 assert(ik()->implements_interface(method_holder) , "this class should implement the interface");
495 assert(is_miranda(m, ik()->methods(), ik()->super()), "should be a miranda_method");
496 return true;
497 }
498 return false;
499 }
500
501 // check if a method is a miranda method, given a class's methods table and it's super
502 // the caller must make sure that the method belongs to an interface implemented by the class
503 bool klassVtable::is_miranda(methodOop m, objArrayOop class_methods, klassOop super) {
504 symbolOop name = m->name();
505 symbolOop signature = m->signature();
506 if (instanceKlass::find_method(class_methods, name, signature) == NULL) {
507 // did not find it in the method table of the current class
508 if (super == NULL) {
509 // super doesn't exist
510 return true;
511 } else {
512 if (instanceKlass::cast(super)->lookup_method(name, signature) == NULL) {
513 // super class hierarchy does not implement it
514 return true;
515 }
516 }
517 }
518 return false;
519 }
520
521 void klassVtable::add_new_mirandas_to_list(GrowableArray<methodOop>* list_of_current_mirandas,
522 objArrayOop current_interface_methods,
523 objArrayOop class_methods,
524 klassOop super) {
525 // iterate thru the current interface's method to see if it a miranda
526 int num_methods = current_interface_methods->length();
527 for (int i = 0; i < num_methods; i++) {
528 methodOop im = methodOop(current_interface_methods->obj_at(i));
529 bool is_duplicate = false;
530 int num_of_current_mirandas = list_of_current_mirandas->length();
531 // check for duplicate mirandas in different interfaces we implement
532 for (int j = 0; j < num_of_current_mirandas; j++) {
533 methodOop miranda = list_of_current_mirandas->at(j);
534 if ((im->name() == miranda->name()) &&
535 (im->signature() == miranda->signature())) {
536 is_duplicate = true;
537 break;
538 }
539 }
540
541 if (!is_duplicate) { // we don't want duplicate miranda entries in the vtable
542 if (is_miranda(im, class_methods, super)) { // is it a miranda at all?
543 instanceKlass *sk = instanceKlass::cast(super);
544 // check if it is a duplicate of a super's miranda
545 if (sk->lookup_method_in_all_interfaces(im->name(), im->signature()) == NULL) {
546 list_of_current_mirandas->append(im);
547 }
548 }
549 }
550 }
551 }
552
553 void klassVtable::get_mirandas(GrowableArray<methodOop>* mirandas,
554 klassOop super, objArrayOop class_methods,
555 objArrayOop local_interfaces) {
556 assert((mirandas->length() == 0) , "current mirandas must be 0");
557
558 // iterate thru the local interfaces looking for a miranda
559 int num_local_ifs = local_interfaces->length();
560 for (int i = 0; i < num_local_ifs; i++) {
561 instanceKlass *ik = instanceKlass::cast(klassOop(local_interfaces->obj_at(i)));
562 add_new_mirandas_to_list(mirandas, ik->methods(), class_methods, super);
563 // iterate thru each local's super interfaces
564 objArrayOop super_ifs = ik->transitive_interfaces();
565 int num_super_ifs = super_ifs->length();
566 for (int j = 0; j < num_super_ifs; j++) {
567 instanceKlass *sik = instanceKlass::cast(klassOop(super_ifs->obj_at(j)));
568 add_new_mirandas_to_list(mirandas, sik->methods(), class_methods, super);
569 }
570 }
571 }
572
573 // get number of mirandas
574 int klassVtable::get_num_mirandas(klassOop super, objArrayOop class_methods, objArrayOop local_interfaces) {
575 ResourceMark rm;
576 GrowableArray<methodOop>* mirandas = new GrowableArray<methodOop>(20);
577 get_mirandas(mirandas, super, class_methods, local_interfaces);
578 return mirandas->length();
579 }
580
581 // fill in mirandas
582 void klassVtable::fill_in_mirandas(int& initialized) {
583 ResourceMark rm;
584 GrowableArray<methodOop>* mirandas = new GrowableArray<methodOop>(20);
585 instanceKlass *this_ik = ik();
586 get_mirandas(mirandas, this_ik->super(), this_ik->methods(), this_ik->local_interfaces());
587 int num_mirandas = mirandas->length();
588 for (int i = 0; i < num_mirandas; i++) {
589 put_method_at(mirandas->at(i), initialized);
590 initialized++;
591 }
592 }
593
594 void klassVtable::copy_vtable_to(vtableEntry* start) {
595 Copy::disjoint_words((HeapWord*)table(), (HeapWord*)start, _length * vtableEntry::size());
596 }
597
598 void klassVtable::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
599 int methods_length, bool * trace_name_printed) {
600 // search the vtable for uses of either obsolete or EMCP methods
601 for (int j = 0; j < methods_length; j++) {
602 methodOop old_method = old_methods[j];
603 methodOop new_method = new_methods[j];
604
605 // In the vast majority of cases we could get the vtable index
606 // by using: old_method->vtable_index()
607 // However, there are rare cases, eg. sun.awt.X11.XDecoratedPeer.getX()
608 // in sun.awt.X11.XFramePeer where methods occur more than once in the
609 // vtable, so, alas, we must do an exhaustive search.
610 for (int index = 0; index < length(); index++) {
611 if (unchecked_method_at(index) == old_method) {
612 put_method_at(new_method, index);
613
614 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
615 if (!(*trace_name_printed)) {
616 // RC_TRACE_MESG macro has an embedded ResourceMark
617 RC_TRACE_MESG(("adjust: name=%s",
618 Klass::cast(old_method->method_holder())->external_name()));
619 *trace_name_printed = true;
620 }
621 // RC_TRACE macro has an embedded ResourceMark
622 RC_TRACE(0x00100000, ("vtable method update: %s(%s)",
623 new_method->name()->as_C_string(),
624 new_method->signature()->as_C_string()));
625 }
626 }
627 }
628 }
629 }
630
631
632 // Garbage collection
633 void klassVtable::oop_follow_contents() {
634 int len = length();
635 for (int i = 0; i < len; i++) {
636 MarkSweep::mark_and_push(adr_method_at(i));
637 }
638 }
639
640 #ifndef SERIALGC
641 void klassVtable::oop_follow_contents(ParCompactionManager* cm) {
642 int len = length();
643 for (int i = 0; i < len; i++) {
644 PSParallelCompact::mark_and_push(cm, adr_method_at(i));
645 }
646 }
647 #endif // SERIALGC
648
649 void klassVtable::oop_adjust_pointers() {
650 int len = length();
651 for (int i = 0; i < len; i++) {
652 MarkSweep::adjust_pointer(adr_method_at(i));
653 }
654 }
655
656 #ifndef SERIALGC
657 void klassVtable::oop_update_pointers(ParCompactionManager* cm) {
658 const int n = length();
659 for (int i = 0; i < n; i++) {
660 PSParallelCompact::adjust_pointer(adr_method_at(i));
661 }
662 }
663
664 void klassVtable::oop_update_pointers(ParCompactionManager* cm,
665 HeapWord* beg_addr, HeapWord* end_addr) {
666 const int n = length();
667 const int entry_size = vtableEntry::size();
668
669 int beg_idx = 0;
670 HeapWord* const method_0 = (HeapWord*)adr_method_at(0);
671 if (beg_addr > method_0) {
672 // it's safe to use cast, as we have guarantees on vtable size to be sane
673 beg_idx = int((pointer_delta(beg_addr, method_0) + entry_size - 1) / entry_size);
674 }
675
676 oop* const beg_oop = adr_method_at(beg_idx);
677 oop* const end_oop = MIN2((oop*)end_addr, adr_method_at(n));
678 for (oop* cur_oop = beg_oop; cur_oop < end_oop; cur_oop += entry_size) {
679 PSParallelCompact::adjust_pointer(cur_oop);
680 }
681 }
682 #endif // SERIALGC
683
684 // Iterators
685 void klassVtable::oop_oop_iterate(OopClosure* blk) {
686 int len = length();
687 for (int i = 0; i < len; i++) {
688 blk->do_oop(adr_method_at(i));
689 }
690 }
691
692 void klassVtable::oop_oop_iterate_m(OopClosure* blk, MemRegion mr) {
693 int len = length();
694 int i;
695 for (i = 0; i < len; i++) {
696 if ((HeapWord*)adr_method_at(i) >= mr.start()) break;
697 }
698 for (; i < len; i++) {
699 oop* adr = adr_method_at(i);
700 if ((HeapWord*)adr < mr.end()) blk->do_oop(adr);
701 }
702 }
703
704 //-----------------------------------------------------------------------------------------
705 // Itable code
706
707 // Initialize a itableMethodEntry
708 void itableMethodEntry::initialize(methodOop m) {
709 if (m == NULL) return;
710
711 _method = m;
712 }
713
714 klassItable::klassItable(instanceKlassHandle klass) {
715 _klass = klass;
716
717 if (klass->itable_length() > 0) {
718 itableOffsetEntry* offset_entry = (itableOffsetEntry*)klass->start_of_itable();
719 if (offset_entry != NULL && offset_entry->interface_klass() != NULL) { // Check that itable is initialized
720 // First offset entry points to the first method_entry
721 intptr_t* method_entry = (intptr_t *)(((address)klass->as_klassOop()) + offset_entry->offset());
722 intptr_t* end = klass->end_of_itable();
723
724 _table_offset = (intptr_t*)offset_entry - (intptr_t*)klass->as_klassOop();
725 _size_offset_table = (method_entry - ((intptr_t*)offset_entry)) / itableOffsetEntry::size();
726 _size_method_table = (end - method_entry) / itableMethodEntry::size();
727 assert(_table_offset >= 0 && _size_offset_table >= 0 && _size_method_table >= 0, "wrong computation");
728 return;
729 }
730 }
731
732 // The length of the itable was either zero, or it has not yet been initialized.
733 _table_offset = 0;
734 _size_offset_table = 0;
735 _size_method_table = 0;
736 }
737
738 // Garbage Collection
739
740 void klassItable::oop_follow_contents() {
741 // offset table
742 itableOffsetEntry* ioe = offset_entry(0);
743 for(int i = 0; i < _size_offset_table; i++) {
744 MarkSweep::mark_and_push((oop*)&ioe->_interface);
745 ioe++;
746 }
747
748 // method table
749 itableMethodEntry* ime = method_entry(0);
750 for(int j = 0; j < _size_method_table; j++) {
751 MarkSweep::mark_and_push((oop*)&ime->_method);
752 ime++;
753 }
754 }
755
756 #ifndef SERIALGC
757 void klassItable::oop_follow_contents(ParCompactionManager* cm) {
758 // offset table
759 itableOffsetEntry* ioe = offset_entry(0);
760 for(int i = 0; i < _size_offset_table; i++) {
761 PSParallelCompact::mark_and_push(cm, (oop*)&ioe->_interface);
762 ioe++;
763 }
764
765 // method table
766 itableMethodEntry* ime = method_entry(0);
767 for(int j = 0; j < _size_method_table; j++) {
768 PSParallelCompact::mark_and_push(cm, (oop*)&ime->_method);
769 ime++;
770 }
771 }
772 #endif // SERIALGC
773
774 void klassItable::oop_adjust_pointers() {
775 // offset table
776 itableOffsetEntry* ioe = offset_entry(0);
777 for(int i = 0; i < _size_offset_table; i++) {
778 MarkSweep::adjust_pointer((oop*)&ioe->_interface);
779 ioe++;
780 }
781
782 // method table
783 itableMethodEntry* ime = method_entry(0);
784 for(int j = 0; j < _size_method_table; j++) {
785 MarkSweep::adjust_pointer((oop*)&ime->_method);
786 ime++;
787 }
788 }
789
790 #ifndef SERIALGC
791 void klassItable::oop_update_pointers(ParCompactionManager* cm) {
792 // offset table
793 itableOffsetEntry* ioe = offset_entry(0);
794 for(int i = 0; i < _size_offset_table; i++) {
795 PSParallelCompact::adjust_pointer((oop*)&ioe->_interface);
796 ioe++;
797 }
798
799 // method table
800 itableMethodEntry* ime = method_entry(0);
801 for(int j = 0; j < _size_method_table; j++) {
802 PSParallelCompact::adjust_pointer((oop*)&ime->_method);
803 ime++;
804 }
805 }
806
807 void klassItable::oop_update_pointers(ParCompactionManager* cm,
808 HeapWord* beg_addr, HeapWord* end_addr) {
809 // offset table
810 itableOffsetEntry* ioe = offset_entry(0);
811 for(int i = 0; i < _size_offset_table; i++) {
812 oop* p = (oop*)&ioe->_interface;
813 PSParallelCompact::adjust_pointer(p, beg_addr, end_addr);
814 ioe++;
815 }
816
817 // method table
818 itableMethodEntry* ime = method_entry(0);
819 for(int j = 0; j < _size_method_table; j++) {
820 oop* p = (oop*)&ime->_method;
821 PSParallelCompact::adjust_pointer(p, beg_addr, end_addr);
822 ime++;
823 }
824 }
825 #endif // SERIALGC
826
827 // Iterators
828 void klassItable::oop_oop_iterate(OopClosure* blk) {
829 // offset table
830 itableOffsetEntry* ioe = offset_entry(0);
831 for(int i = 0; i < _size_offset_table; i++) {
832 blk->do_oop((oop*)&ioe->_interface);
833 ioe++;
834 }
835
836 // method table
837 itableMethodEntry* ime = method_entry(0);
838 for(int j = 0; j < _size_method_table; j++) {
839 blk->do_oop((oop*)&ime->_method);
840 ime++;
841 }
842 }
843
844 void klassItable::oop_oop_iterate_m(OopClosure* blk, MemRegion mr) {
845 // offset table
846 itableOffsetEntry* ioe = offset_entry(0);
847 for(int i = 0; i < _size_offset_table; i++) {
848 oop* adr = (oop*)&ioe->_interface;
849 if (mr.contains(adr)) blk->do_oop(adr);
850 ioe++;
851 }
852
853 // method table
854 itableMethodEntry* ime = method_entry(0);
855 for(int j = 0; j < _size_method_table; j++) {
856 oop* adr = (oop*)&ime->_method;
857 if (mr.contains(adr)) blk->do_oop(adr);
858 ime++;
859 }
860 }
861
862
863 static int initialize_count = 0;
864
865 // Initialization
866 void klassItable::initialize_itable(bool checkconstraints, TRAPS) {
867 // Cannot be setup doing bootstrapping, interfaces don't have
868 // itables, and klass with only ones entry have empty itables
869 if (Universe::is_bootstrapping() ||
870 _klass->is_interface() ||
871 _klass->itable_length() == itableOffsetEntry::size()) return;
872
873 // There's alway an extra itable entry so we can null-terminate it.
874 guarantee(size_offset_table() >= 1, "too small");
875 int num_interfaces = size_offset_table() - 1;
876 if (num_interfaces > 0) {
877 if (TraceItables) tty->print_cr("%3d: Initializing itables for %s", ++initialize_count,
878 _klass->name()->as_C_string());
879
880
881 // Iterate through all interfaces
882 int i;
883 for(i = 0; i < num_interfaces; i++) {
884 itableOffsetEntry* ioe = offset_entry(i);
885 KlassHandle interf_h (THREAD, ioe->interface_klass());
886 assert(interf_h() != NULL && ioe->offset() != 0, "bad offset entry in itable");
887 initialize_itable_for_interface(ioe->offset(), interf_h, checkconstraints, CHECK);
888 }
889
890 }
891 // Check that the last entry is empty
892 itableOffsetEntry* ioe = offset_entry(size_offset_table() - 1);
893 guarantee(ioe->interface_klass() == NULL && ioe->offset() == 0, "terminator entry missing");
894 }
895
896
897 void klassItable::initialize_itable_for_interface(int method_table_offset, KlassHandle interf_h, bool checkconstraints, TRAPS) {
898 objArrayHandle methods(THREAD, instanceKlass::cast(interf_h())->methods());
899 int nof_methods = methods()->length();
900 HandleMark hm;
901 KlassHandle klass = _klass;
902 assert(nof_methods > 0, "at least one method must exist for interface to be in vtable");
903 Handle interface_loader (THREAD, instanceKlass::cast(interf_h())->class_loader());
904 int ime_num = 0;
905
906 // Skip first methodOop if it is a class initializer
907 int i = ((methodOop)methods()->obj_at(0))->name() != vmSymbols::class_initializer_name() ? 0 : 1;
908
909 // m, method_name, method_signature, klass reset each loop so they
910 // don't need preserving across check_signature_loaders call
911 // methods needs a handle in case of gc from check_signature_loaders
912 for(; i < nof_methods; i++) {
913 methodOop m = (methodOop)methods()->obj_at(i);
914 symbolOop method_name = m->name();
915 symbolOop method_signature = m->signature();
916
917 // This is same code as in Linkresolver::lookup_instance_method_in_klasses
918 methodOop target = klass->uncached_lookup_method(method_name, method_signature);
919 while (target != NULL && target->is_static()) {
920 // continue with recursive lookup through the superclass
921 klassOop super = Klass::cast(target->method_holder())->super();
922 target = (super == NULL) ? methodOop(NULL) : Klass::cast(super)->uncached_lookup_method(method_name, method_signature);
923 }
924 if (target == NULL || !target->is_public() || target->is_abstract()) {
925 // Entry do not resolve. Leave it empty
926 } else {
927 // Entry did resolve, check loader constraints before initializing
928 // if checkconstraints requested
929 methodHandle target_h (THREAD, target); // preserve across gc
930 if (checkconstraints) {
931 Handle method_holder_loader (THREAD, instanceKlass::cast(target->method_holder())->class_loader());
932 if (method_holder_loader() != interface_loader()) {
933 ResourceMark rm(THREAD);
934 char* failed_type_name =
935 SystemDictionary::check_signature_loaders(method_signature,
936 method_holder_loader,
937 interface_loader,
938 true, CHECK);
939 if (failed_type_name != NULL) {
940 const char* msg = "loader constraint violation in interface "
941 "itable initialization: when resolving method \"%s\" the class"
942 " loader (instance of %s) of the current class, %s, "
943 "and the class loader (instance of %s) for interface "
944 "%s have different Class objects for the type %s "
945 "used in the signature";
946 char* sig = target_h()->name_and_sig_as_C_string();
947 const char* loader1 = SystemDictionary::loader_name(method_holder_loader());
948 char* current = klass->name()->as_C_string();
949 const char* loader2 = SystemDictionary::loader_name(interface_loader());
950 char* iface = instanceKlass::cast(interf_h())->name()->as_C_string();
951 size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) +
952 strlen(current) + strlen(loader2) + strlen(iface) +
953 strlen(failed_type_name);
954 char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
955 jio_snprintf(buf, buflen, msg, sig, loader1, current, loader2,
956 iface, failed_type_name);
957 THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
958 }
959 }
960 }
961
962 // ime may have moved during GC so recalculate address
963 itableOffsetEntry::method_entry(_klass(), method_table_offset)[ime_num].initialize(target_h());
964 }
965 // Progress to next entry
966 ime_num++;
967 }
968 }
969
970 // Update entry for specific methodOop
971 void klassItable::initialize_with_method(methodOop m) {
972 itableMethodEntry* ime = method_entry(0);
973 for(int i = 0; i < _size_method_table; i++) {
974 if (ime->method() == m) {
975 ime->initialize(m);
976 }
977 ime++;
978 }
979 }
980
981 void klassItable::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
982 int methods_length, bool * trace_name_printed) {
983 // search the itable for uses of either obsolete or EMCP methods
984 for (int j = 0; j < methods_length; j++) {
985 methodOop old_method = old_methods[j];
986 methodOop new_method = new_methods[j];
987 itableMethodEntry* ime = method_entry(0);
988
989 // The itable can describe more than one interface and the same
990 // method signature can be specified by more than one interface.
991 // This means we have to do an exhaustive search to find all the
992 // old_method references.
993 for (int i = 0; i < _size_method_table; i++) {
994 if (ime->method() == old_method) {
995 ime->initialize(new_method);
996
997 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
998 if (!(*trace_name_printed)) {
999 // RC_TRACE_MESG macro has an embedded ResourceMark
1000 RC_TRACE_MESG(("adjust: name=%s",
1001 Klass::cast(old_method->method_holder())->external_name()));
1002 *trace_name_printed = true;
1003 }
1004 // RC_TRACE macro has an embedded ResourceMark
1005 RC_TRACE(0x00200000, ("itable method update: %s(%s)",
1006 new_method->name()->as_C_string(),
1007 new_method->signature()->as_C_string()));
1008 }
1009 break;
1010 }
1011 ime++;
1012 }
1013 }
1014 }
1015
1016
1017 // Setup
1018 class InterfaceVisiterClosure : public StackObj {
1019 public:
1020 virtual void doit(klassOop intf, int method_count) = 0;
1021 };
1022
1023 // Visit all interfaces with at-least one method (excluding <clinit>)
1024 void visit_all_interfaces(objArrayOop transitive_intf, InterfaceVisiterClosure *blk) {
1025 // Handle array argument
1026 for(int i = 0; i < transitive_intf->length(); i++) {
1027 klassOop intf = (klassOop)transitive_intf->obj_at(i);
1028 assert(Klass::cast(intf)->is_interface(), "sanity check");
1029
1030 // Find no. of methods excluding a <clinit>
1031 int method_count = instanceKlass::cast(intf)->methods()->length();
1032 if (method_count > 0) {
1033 methodOop m = (methodOop)instanceKlass::cast(intf)->methods()->obj_at(0);
1034 assert(m != NULL && m->is_method(), "sanity check");
1035 if (m->name() == vmSymbols::object_initializer_name()) {
1036 method_count--;
1037 }
1038 }
1039
1040 // Only count interfaces with at least one method
1041 if (method_count > 0) {
1042 blk->doit(intf, method_count);
1043 }
1044 }
1045 }
1046
1047 class CountInterfacesClosure : public InterfaceVisiterClosure {
1048 private:
1049 int _nof_methods;
1050 int _nof_interfaces;
1051 public:
1052 CountInterfacesClosure() { _nof_methods = 0; _nof_interfaces = 0; }
1053
1054 int nof_methods() const { return _nof_methods; }
1055 int nof_interfaces() const { return _nof_interfaces; }
1056
1057 void doit(klassOop intf, int method_count) { _nof_methods += method_count; _nof_interfaces++; }
1058 };
1059
1060 class SetupItableClosure : public InterfaceVisiterClosure {
1061 private:
1062 itableOffsetEntry* _offset_entry;
1063 itableMethodEntry* _method_entry;
1064 address _klass_begin;
1065 public:
1066 SetupItableClosure(address klass_begin, itableOffsetEntry* offset_entry, itableMethodEntry* method_entry) {
1067 _klass_begin = klass_begin;
1068 _offset_entry = offset_entry;
1069 _method_entry = method_entry;
1070 }
1071
1072 itableMethodEntry* method_entry() const { return _method_entry; }
1073
1074 void doit(klassOop intf, int method_count) {
1075 int offset = ((address)_method_entry) - _klass_begin;
1076 _offset_entry->initialize(intf, offset);
1077 _offset_entry++;
1078 _method_entry += method_count;
1079 }
1080 };
1081
1082 int klassItable::compute_itable_size(objArrayHandle transitive_interfaces) {
1083 // Count no of interfaces and total number of interface methods
1084 CountInterfacesClosure cic;
1085 visit_all_interfaces(transitive_interfaces(), &cic);
1086
1087 // There's alway an extra itable entry so we can null-terminate it.
1088 int itable_size = calc_itable_size(cic.nof_interfaces() + 1, cic.nof_methods());
1089
1090 // Statistics
1091 update_stats(itable_size * HeapWordSize);
1092
1093 return itable_size;
1094 }
1095
1096
1097 // Fill out offset table and interface klasses into the itable space
1098 void klassItable::setup_itable_offset_table(instanceKlassHandle klass) {
1099 if (klass->itable_length() == 0) return;
1100 assert(!klass->is_interface(), "Should have zero length itable");
1101
1102 // Count no of interfaces and total number of interface methods
1103 CountInterfacesClosure cic;
1104 visit_all_interfaces(klass->transitive_interfaces(), &cic);
1105 int nof_methods = cic.nof_methods();
1106 int nof_interfaces = cic.nof_interfaces();
1107
1108 // Add one extra entry so we can null-terminate the table
1109 nof_interfaces++;
1110
1111 assert(compute_itable_size(objArrayHandle(klass->transitive_interfaces())) ==
1112 calc_itable_size(nof_interfaces, nof_methods),
1113 "mismatch calculation of itable size");
1114
1115 // Fill-out offset table
1116 itableOffsetEntry* ioe = (itableOffsetEntry*)klass->start_of_itable();
1117 itableMethodEntry* ime = (itableMethodEntry*)(ioe + nof_interfaces);
1118 intptr_t* end = klass->end_of_itable();
1119 assert((oop*)(ime + nof_methods) <= (oop*)klass->start_of_static_fields(), "wrong offset calculation (1)");
1120 assert((oop*)(end) == (oop*)(ime + nof_methods), "wrong offset calculation (2)");
1121
1122 // Visit all interfaces and initialize itable offset table
1123 SetupItableClosure sic((address)klass->as_klassOop(), ioe, ime);
1124 visit_all_interfaces(klass->transitive_interfaces(), &sic);
1125
1126 #ifdef ASSERT
1127 ime = sic.method_entry();
1128 oop* v = (oop*) klass->end_of_itable();
1129 assert( (oop*)(ime) == v, "wrong offset calculation (2)");
1130 #endif
1131 }
1132
1133
1134 // m must be a method in an interface
1135 int klassItable::compute_itable_index(methodOop m) {
1136 klassOop intf = m->method_holder();
1137 assert(instanceKlass::cast(intf)->is_interface(), "sanity check");
1138 objArrayOop methods = instanceKlass::cast(intf)->methods();
1139 int index = 0;
1140 while(methods->obj_at(index) != m) {
1141 index++;
1142 assert(index < methods->length(), "should find index for resolve_invoke");
1143 }
1144 // Adjust for <clinit>, which is left out of table if first method
1145 if (methods->length() > 0 && ((methodOop)methods->obj_at(0))->name() == vmSymbols::class_initializer_name()) {
1146 index--;
1147 }
1148 return index;
1149 }
1150
1151
1152 // inverse to compute_itable_index
1153 methodOop klassItable::method_for_itable_index(klassOop intf, int itable_index) {
1154 assert(instanceKlass::cast(intf)->is_interface(), "sanity check");
1155 objArrayOop methods = instanceKlass::cast(intf)->methods();
1156
1157 int index = itable_index;
1158 // Adjust for <clinit>, which is left out of table if first method
1159 if (methods->length() > 0 && ((methodOop)methods->obj_at(0))->name() == vmSymbols::class_initializer_name()) {
1160 index++;
1161 }
1162
1163 if (itable_index < 0 || index >= methods->length())
1164 return NULL; // help caller defend against bad indexes
1165
1166 methodOop m = (methodOop)methods->obj_at(index);
1167 assert(compute_itable_index(m) == itable_index, "correct inverse");
1168
1169 return m;
1170 }
1171
1172 void klassVtable::verify(outputStream* st, bool forced) {
1173 // make sure table is initialized
1174 if (!Universe::is_fully_initialized()) return;
1175 #ifndef PRODUCT
1176 // avoid redundant verifies
1177 if (!forced && _verify_count == Universe::verify_count()) return;
1178 _verify_count = Universe::verify_count();
1179 #endif
1180 oop* end_of_obj = (oop*)_klass() + _klass()->size();
1181 oop* end_of_vtable = (oop *)&table()[_length];
1182 if (end_of_vtable > end_of_obj) {
1183 fatal(err_msg("klass %s: klass object too short (vtable extends beyond "
1184 "end)", _klass->internal_name()));
1185 }
1186
1187 for (int i = 0; i < _length; i++) table()[i].verify(this, st);
1188 // verify consistency with superKlass vtable
1189 klassOop super = _klass->super();
1190 if (super != NULL) {
1191 instanceKlass* sk = instanceKlass::cast(super);
1192 klassVtable* vt = sk->vtable();
1193 for (int i = 0; i < vt->length(); i++) {
1194 verify_against(st, vt, i);
1195 }
1196 }
1197 }
1198
1199 void klassVtable::verify_against(outputStream* st, klassVtable* vt, int index) {
1200 vtableEntry* vte = &vt->table()[index];
1201 if (vte->method()->name() != table()[index].method()->name() ||
1202 vte->method()->signature() != table()[index].method()->signature()) {
1203 fatal("mismatched name/signature of vtable entries");
1204 }
1205 }
1206
1207 #ifndef PRODUCT
1208 void klassVtable::print() {
1209 ResourceMark rm;
1210 tty->print("klassVtable for klass %s (length %d):\n", _klass->internal_name(), length());
1211 for (int i = 0; i < length(); i++) {
1212 table()[i].print();
1213 tty->cr();
1214 }
1215 }
1216 #endif
1217
1218 void vtableEntry::verify(klassVtable* vt, outputStream* st) {
1219 NOT_PRODUCT(FlagSetting fs(IgnoreLockingAssertions, true));
1220 assert(method() != NULL, "must have set method");
1221 method()->verify();
1222 // we sub_type, because it could be a miranda method
1223 if (!vt->klass()->is_subtype_of(method()->method_holder())) {
1224 #ifndef PRODUCT
1225 print();
1226 #endif
1227 fatal(err_msg("vtableEntry " PTR_FORMAT ": method is from subclass", this));
1228 }
1229 }
1230
1231 #ifndef PRODUCT
1232
1233 void vtableEntry::print() {
1234 ResourceMark rm;
1235 tty->print("vtableEntry %s: ", method()->name()->as_C_string());
1236 if (Verbose) {
1237 tty->print("m %#lx ", (address)method());
1238 }
1239 }
1240
1241 class VtableStats : AllStatic {
1242 public:
1243 static int no_klasses; // # classes with vtables
1244 static int no_array_klasses; // # array classes
1245 static int no_instance_klasses; // # instanceKlasses
1246 static int sum_of_vtable_len; // total # of vtable entries
1247 static int sum_of_array_vtable_len; // total # of vtable entries in array klasses only
1248 static int fixed; // total fixed overhead in bytes
1249 static int filler; // overhead caused by filler bytes
1250 static int entries; // total bytes consumed by vtable entries
1251 static int array_entries; // total bytes consumed by array vtable entries
1252
1253 static void do_class(klassOop k) {
1254 Klass* kl = k->klass_part();
1255 klassVtable* vt = kl->vtable();
1256 if (vt == NULL) return;
1257 no_klasses++;
1258 if (kl->oop_is_instance()) {
1259 no_instance_klasses++;
1260 kl->array_klasses_do(do_class);
1261 }
1262 if (kl->oop_is_array()) {
1263 no_array_klasses++;
1264 sum_of_array_vtable_len += vt->length();
1265 }
1266 sum_of_vtable_len += vt->length();
1267 }
1268
1269 static void compute() {
1270 SystemDictionary::classes_do(do_class);
1271 fixed = no_klasses * oopSize; // vtable length
1272 // filler size is a conservative approximation
1273 filler = oopSize * (no_klasses - no_instance_klasses) * (sizeof(instanceKlass) - sizeof(arrayKlass) - 1);
1274 entries = sizeof(vtableEntry) * sum_of_vtable_len;
1275 array_entries = sizeof(vtableEntry) * sum_of_array_vtable_len;
1276 }
1277 };
1278
1279 int VtableStats::no_klasses = 0;
1280 int VtableStats::no_array_klasses = 0;
1281 int VtableStats::no_instance_klasses = 0;
1282 int VtableStats::sum_of_vtable_len = 0;
1283 int VtableStats::sum_of_array_vtable_len = 0;
1284 int VtableStats::fixed = 0;
1285 int VtableStats::filler = 0;
1286 int VtableStats::entries = 0;
1287 int VtableStats::array_entries = 0;
1288
1289 void klassVtable::print_statistics() {
1290 ResourceMark rm;
1291 HandleMark hm;
1292 VtableStats::compute();
1293 tty->print_cr("vtable statistics:");
1294 tty->print_cr("%6d classes (%d instance, %d array)", VtableStats::no_klasses, VtableStats::no_instance_klasses, VtableStats::no_array_klasses);
1295 int total = VtableStats::fixed + VtableStats::filler + VtableStats::entries;
1296 tty->print_cr("%6d bytes fixed overhead (refs + vtable object header)", VtableStats::fixed);
1297 tty->print_cr("%6d bytes filler overhead", VtableStats::filler);
1298 tty->print_cr("%6d bytes for vtable entries (%d for arrays)", VtableStats::entries, VtableStats::array_entries);
1299 tty->print_cr("%6d bytes total", total);
1300 }
1301
1302 bool klassVtable::check_no_old_entries() {
1303 // Check that there really is no entry
1304 for (int i = 0; i < length(); i++) {
1305 methodOop m = unchecked_method_at(i);
1306 if (m != NULL) {
1307 if (m->is_old()) {
1308 return false;
1309 }
1310 }
1311 }
1312 return true;
1313 }
1314
1315 void klassVtable::dump_vtable() {
1316 tty->print_cr("vtable dump --");
1317 for (int i = 0; i < length(); i++) {
1318 methodOop m = unchecked_method_at(i);
1319 if (m != NULL) {
1320 tty->print(" (%5d) ", i);
1321 m->access_flags().print_on(tty);
1322 tty->print(" -- ");
1323 m->print_name(tty);
1324 tty->cr();
1325 }
1326 }
1327 }
1328
1329 int klassItable::_total_classes; // Total no. of classes with itables
1330 long klassItable::_total_size; // Total no. of bytes used for itables
1331
1332 void klassItable::print_statistics() {
1333 tty->print_cr("itable statistics:");
1334 tty->print_cr("%6d classes with itables", _total_classes);
1335 tty->print_cr("%6d K uses for itables (average by class: %d bytes)", _total_size / K, _total_size / _total_classes);
1336 }
1337
1338 #endif // PRODUCT