Fri, 20 Mar 2009 23:19:36 -0700
6814659: separable cleanups and subroutines for 6655638
Summary: preparatory but separable changes for method handles
Reviewed-by: kvn, never
1 /*
2 * Copyright 1997-2009 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
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23 */
25 #include "incls/_precompiled.incl"
26 #include "incls/_klassVtable.cpp.incl"
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 }
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 oop classloader,
49 symbolOop classname,
50 objArrayOop local_interfaces
51 ) {
53 No_Safepoint_Verifier nsv;
55 // set up default result values
56 vtable_length = 0;
57 num_miranda_methods = 0;
59 // start off with super's vtable length
60 instanceKlass* sk = (instanceKlass*)super->klass_part();
61 vtable_length = super == NULL ? 0 : sk->vtable_length();
63 // go thru each method in the methods table to see if it needs a new entry
64 int len = methods->length();
65 for (int i = 0; i < len; i++) {
66 assert(methods->obj_at(i)->is_method(), "must be a methodOop");
67 methodOop m = methodOop(methods->obj_at(i));
69 if (needs_new_vtable_entry(m, super, classloader, classname, class_flags)) {
70 vtable_length += vtableEntry::size(); // we need a new entry
71 }
72 }
74 // compute the number of mirandas methods that must be added to the end
75 num_miranda_methods = get_num_mirandas(super, methods, local_interfaces);
76 vtable_length += (num_miranda_methods * vtableEntry::size());
78 if (Universe::is_bootstrapping() && vtable_length == 0) {
79 // array classes don't have their superclass set correctly during
80 // bootstrapping
81 vtable_length = Universe::base_vtable_size();
82 }
84 if (super == NULL && !Universe::is_bootstrapping() &&
85 vtable_length != Universe::base_vtable_size()) {
86 // Someone is attempting to redefine java.lang.Object incorrectly. The
87 // only way this should happen is from
88 // SystemDictionary::resolve_from_stream(), which will detect this later
89 // and throw a security exception. So don't assert here to let
90 // the exception occur.
91 vtable_length = Universe::base_vtable_size();
92 }
93 assert(super != NULL || vtable_length == Universe::base_vtable_size(),
94 "bad vtable size for class Object");
95 assert(vtable_length % vtableEntry::size() == 0, "bad vtable length");
96 assert(vtable_length >= Universe::base_vtable_size(), "vtable too small");
97 }
99 int klassVtable::index_of(methodOop m, int len) const {
100 assert(m->vtable_index() >= 0, "do not ask this of non-vtable methods");
101 return m->vtable_index();
102 }
104 int klassVtable::initialize_from_super(KlassHandle super) {
105 if (super.is_null()) {
106 return 0;
107 } else {
108 // copy methods from superKlass
109 // can't inherit from array class, so must be instanceKlass
110 assert(super->oop_is_instance(), "must be instance klass");
111 instanceKlass* sk = (instanceKlass*)super()->klass_part();
112 klassVtable* superVtable = sk->vtable();
113 assert(superVtable->length() <= _length, "vtable too short");
114 #ifdef ASSERT
115 superVtable->verify(tty, true);
116 #endif
117 superVtable->copy_vtable_to(table());
118 #ifndef PRODUCT
119 if (PrintVtables && Verbose) {
120 tty->print_cr("copy vtable from %s to %s size %d", sk->internal_name(), klass()->internal_name(), _length);
121 }
122 #endif
123 return superVtable->length();
124 }
125 }
127 // Revised lookup semantics introduced 1.3 (Kestral beta)
128 void klassVtable::initialize_vtable(bool checkconstraints, TRAPS) {
130 // Note: Arrays can have intermediate array supers. Use java_super to skip them.
131 KlassHandle super (THREAD, klass()->java_super());
132 int nofNewEntries = 0;
135 if (PrintVtables && !klass()->oop_is_array()) {
136 ResourceMark rm(THREAD);
137 tty->print_cr("Initializing: %s", _klass->name()->as_C_string());
138 }
140 #ifdef ASSERT
141 oop* end_of_obj = (oop*)_klass() + _klass()->size();
142 oop* end_of_vtable = (oop*)&table()[_length];
143 assert(end_of_vtable <= end_of_obj, "vtable extends beyond end");
144 #endif
146 if (Universe::is_bootstrapping()) {
147 // just clear everything
148 for (int i = 0; i < _length; i++) table()[i].clear();
149 return;
150 }
152 int super_vtable_len = initialize_from_super(super);
153 if (klass()->oop_is_array()) {
154 assert(super_vtable_len == _length, "arrays shouldn't introduce new methods");
155 } else {
156 assert(_klass->oop_is_instance(), "must be instanceKlass");
158 objArrayHandle methods(THREAD, ik()->methods());
159 int len = methods()->length();
160 int initialized = super_vtable_len;
162 // update_super_vtable can stop for gc - ensure using handles
163 for (int i = 0; i < len; i++) {
164 HandleMark hm(THREAD);
165 assert(methods()->obj_at(i)->is_method(), "must be a methodOop");
166 methodHandle mh(THREAD, (methodOop)methods()->obj_at(i));
168 bool needs_new_entry = update_super_vtable(ik(), mh, super_vtable_len, checkconstraints, CHECK);
170 if (needs_new_entry) {
171 put_method_at(mh(), initialized);
172 mh()->set_vtable_index(initialized); // set primary vtable index
173 initialized++;
174 }
175 }
177 // add miranda methods; it will also update the value of initialized
178 fill_in_mirandas(initialized);
180 // In class hierachieswhere the accesibility is not increasing (i.e., going from private ->
181 // package_private -> publicprotected), the vtable might actually be smaller than our initial
182 // calculation.
183 assert(initialized <= _length, "vtable initialization failed");
184 for(;initialized < _length; initialized++) {
185 put_method_at(NULL, initialized);
186 }
187 NOT_PRODUCT(verify(tty, true));
188 }
189 }
191 // Interates through the vtables to find the broadest access level. This
192 // will always be monotomic for valid Java programs - but not neccesarily
193 // for incompatible class files.
194 klassVtable::AccessType klassVtable::vtable_accessibility_at(int i) {
195 // This vtable is not implementing the specific method
196 if (i >= length()) return acc_private;
198 // Compute AccessType for current method. public or protected we are done.
199 methodOop m = method_at(i);
200 if (m->is_protected() || m->is_public()) return acc_publicprotected;
202 AccessType acc = m->is_package_private() ? acc_package_private : acc_private;
204 // Compute AccessType for method in super classes
205 klassOop super = klass()->super();
206 AccessType super_acc = (super != NULL) ? instanceKlass::cast(klass()->super())->vtable()->vtable_accessibility_at(i)
207 : acc_private;
209 // Merge
210 return (AccessType)MAX2((int)acc, (int)super_acc);
211 }
214 // Update child's copy of super vtable for overrides
215 // OR return true if a new vtable entry is required
216 // Only called for instanceKlass's, i.e. not for arrays
217 // If that changed, could not use _klass as handle for klass
218 bool klassVtable::update_super_vtable(instanceKlass* klass, methodHandle target_method, int super_vtable_len, bool checkconstraints, TRAPS) {
219 ResourceMark rm;
220 bool allocate_new = true;
221 assert(klass->oop_is_instance(), "must be instanceKlass");
223 // Initialize the method's vtable index to "nonvirtual".
224 // If we allocate a vtable entry, we will update it to a non-negative number.
225 target_method()->set_vtable_index(methodOopDesc::nonvirtual_vtable_index);
227 // Static and <init> methods are never in
228 if (target_method()->is_static() || target_method()->name() == vmSymbols::object_initializer_name()) {
229 return false;
230 }
232 if (klass->is_final() || target_method()->is_final()) {
233 // a final method never needs a new entry; final methods can be statically
234 // resolved and they have to be present in the vtable only if they override
235 // a super's method, in which case they re-use its entry
236 allocate_new = false;
237 }
239 // we need a new entry if there is no superclass
240 if (klass->super() == NULL) {
241 return allocate_new;
242 }
244 // private methods always have a new entry in the vtable
245 if (target_method()->is_private()) {
246 return allocate_new;
247 }
249 // search through the vtable and update overridden entries
250 // Since check_signature_loaders acquires SystemDictionary_lock
251 // which can block for gc, once we are in this loop, use handles, not
252 // unhandled oops unless they are reinitialized for each loop
253 // handles for name, signature, klass, target_method
254 // not for match_method, holder
256 symbolHandle name(THREAD,target_method()->name());
257 symbolHandle signature(THREAD,target_method()->signature());
258 for(int i = 0; i < super_vtable_len; i++) {
259 methodOop match_method = method_at(i);
260 // Check if method name matches
261 if (match_method->name() == name() && match_method->signature() == signature()) {
263 instanceKlass* holder = (THREAD, instanceKlass::cast(match_method->method_holder()));
265 // Check if the match_method is accessable from current class
267 bool same_package_init = false;
268 bool same_package_flag = false;
269 bool simple_match = match_method->is_public() || match_method->is_protected();
270 if (!simple_match) {
271 same_package_init = true;
272 same_package_flag = holder->is_same_class_package(_klass->class_loader(), _klass->name());
274 simple_match = match_method->is_package_private() && same_package_flag;
275 }
276 // match_method is the superclass' method. Note we can't override
277 // and shouldn't access superclass' ACC_PRIVATE methods
278 // (although they have been copied into our vtable)
279 // A simple form of this statement is:
280 // if ( (match_method->is_public() || match_method->is_protected()) ||
281 // (match_method->is_package_private() && holder->is_same_class_package(klass->class_loader(), klass->name()))) {
282 //
283 // The complexity is introduced it avoid recomputing 'is_same_class_package' which is expensive.
284 if (simple_match) {
285 // Check if target_method and match_method has same level of accessibility. The accesibility of the
286 // match method is the "most-general" visibility of all entries at it's particular vtable index for
287 // all superclasses. This check must be done before we override the current entry in the vtable.
288 AccessType at = vtable_accessibility_at(i);
289 bool same_access = false;
291 if ( (at == acc_publicprotected && (target_method()->is_public() || target_method()->is_protected())
292 || (at == acc_package_private && (target_method()->is_package_private() &&
293 (( same_package_init && same_package_flag) ||
294 (!same_package_init && holder->is_same_class_package(_klass->class_loader(), _klass->name()))))))) {
295 same_access = true;
296 }
298 if (checkconstraints) {
299 // Override vtable entry if passes loader constraint check
300 // if loader constraint checking requested
301 // No need to visit his super, since he and his super
302 // have already made any needed loader constraints.
303 // Since loader constraints are transitive, it is enough
304 // to link to the first super, and we get all the others.
305 symbolHandle signature(THREAD, target_method()->signature());
306 Handle this_loader(THREAD, _klass->class_loader());
307 instanceKlassHandle super_klass(THREAD, _klass->super());
308 Handle super_loader(THREAD, super_klass->class_loader());
310 if (this_loader() != super_loader()) {
311 ResourceMark rm(THREAD);
312 char* failed_type_name =
313 SystemDictionary::check_signature_loaders(signature, this_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(this_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 put_method_at(target_method(), i);
338 if (same_access) {
339 // target and match has same accessiblity - share entry
340 allocate_new = false;
341 target_method()->set_vtable_index(i);
342 #ifndef PRODUCT
343 if (PrintVtables && Verbose) {
344 AccessType targetacc;
345 if (target_method()->is_protected() ||
346 target_method()->is_public()) {
347 targetacc = acc_publicprotected;
348 } else {
349 targetacc = target_method()->is_package_private() ? acc_package_private : acc_private;
350 }
351 tty->print_cr("overriding with %s::%s index %d, original flags: %x overriders flags: %x",
352 _klass->internal_name(), (target_method() != NULL) ?
353 target_method()->name()->as_C_string() : "<NULL>", i,
354 at, targetacc);
355 }
356 #endif /*PRODUCT*/
357 } else {
358 #ifndef PRODUCT
359 if (PrintVtables && Verbose) {
360 AccessType targetacc;
361 if (target_method()->is_protected() ||
362 target_method()->is_public()) {
363 targetacc = acc_publicprotected;
364 } else {
365 targetacc = target_method()->is_package_private() ? acc_package_private : acc_private;
366 }
367 tty->print_cr("override %s %s::%s at index %d, original flags: %x overriders flags: %x",
368 allocate_new ? "+ new" : "only",
369 _klass->internal_name(), (target_method() != NULL) ?
370 target_method()->name()->as_C_string() : "<NULL>", i,
371 at, targetacc);
372 }
373 #endif /*PRODUCT*/
374 }
375 }
376 }
377 }
378 return allocate_new;
379 }
383 void klassVtable::put_method_at(methodOop m, int index) {
384 assert(m->is_oop_or_null(), "Not an oop or null");
385 #ifndef PRODUCT
386 if (PrintVtables && Verbose) {
387 tty->print_cr("adding %s::%s at index %d", _klass->internal_name(),
388 (m != NULL) ? m->name()->as_C_string() : "<NULL>", index);
389 }
390 assert(unchecked_method_at(index)->is_oop_or_null(), "Not an oop or null");
391 #endif
392 table()[index].set(m);
393 }
395 // Find out if a method "m" with superclass "super", loader "classloader" and
396 // name "classname" needs a new vtable entry. Let P be a class package defined
397 // by "classloader" and "classname".
398 // NOTE: The logic used here is very similar to the one used for computing
399 // the vtables indices for a method. We cannot directly use that function because,
400 // when the Universe is boostrapping, a super's vtable might not be initialized.
401 bool klassVtable::needs_new_vtable_entry(methodOop target_method,
402 klassOop super,
403 oop classloader,
404 symbolOop classname,
405 AccessFlags class_flags) {
406 if ((class_flags.is_final() || target_method->is_final()) ||
407 // a final method never needs a new entry; final methods can be statically
408 // resolved and they have to be present in the vtable only if they override
409 // a super's method, in which case they re-use its entry
410 (target_method->is_static()) ||
411 // static methods don't need to be in vtable
412 (target_method->name() == vmSymbols::object_initializer_name())
413 // <init> is never called dynamically-bound
414 ) {
415 return false;
416 }
418 // we need a new entry if there is no superclass
419 if (super == NULL) {
420 return true;
421 }
423 // private methods always have a new entry in the vtable
424 if (target_method->is_private()) {
425 return true;
426 }
428 // search through the super class hierarchy to see if we need
429 // a new entry
430 symbolOop name = target_method->name();
431 symbolOop signature = target_method->signature();
432 klassOop k = super;
433 methodOop match_method = NULL;
434 instanceKlass *holder = NULL;
435 while (k != NULL) {
436 // lookup through the hierarchy for a method with matching name and sign.
437 match_method = instanceKlass::cast(k)->lookup_method(name, signature);
438 if (match_method == NULL) {
439 break; // we still have to search for a matching miranda method
440 }
441 // get the class holding the matching method
442 holder = instanceKlass::cast(match_method->method_holder());
444 if (!match_method->is_static()) { // we want only instance method matches
445 if ((target_method->is_public() || target_method->is_protected()) &&
446 (match_method->is_public() || match_method->is_protected())) {
447 // target and match are public/protected; we do not need a new entry
448 return false;
449 }
451 if (target_method->is_package_private() &&
452 match_method->is_package_private() &&
453 holder->is_same_class_package(classloader, classname)) {
454 // target and match are P private; we do not need a new entry
455 return false;
456 }
457 }
459 k = holder->super(); // haven't found a match yet; continue to look
460 }
462 // if the target method is public or protected it may have a matching
463 // miranda method in the super, whose entry it should re-use.
464 if (target_method->is_public() || target_method->is_protected()) {
465 instanceKlass *sk = instanceKlass::cast(super);
466 if (sk->has_miranda_methods()) {
467 if (sk->lookup_method_in_all_interfaces(name, signature) != NULL) {
468 return false; // found a matching miranda; we do not need a new entry
469 }
470 }
471 }
473 return true; // found no match; we need a new entry
474 }
476 // Support for miranda methods
478 // get the vtable index of a miranda method with matching "name" and "signature"
479 int klassVtable::index_of_miranda(symbolOop name, symbolOop signature) {
480 // search from the bottom, might be faster
481 for (int i = (length() - 1); i >= 0; i--) {
482 methodOop m = table()[i].method();
483 if (is_miranda_entry_at(i) &&
484 m->name() == name && m->signature() == signature) {
485 return i;
486 }
487 }
488 return methodOopDesc::invalid_vtable_index;
489 }
491 // check if an entry is miranda
492 bool klassVtable::is_miranda_entry_at(int i) {
493 methodOop m = method_at(i);
494 klassOop method_holder = m->method_holder();
495 instanceKlass *mhk = instanceKlass::cast(method_holder);
497 // miranda methods are interface methods in a class's vtable
498 if (mhk->is_interface()) {
499 assert(m->is_public() && m->is_abstract(), "should be public and abstract");
500 assert(ik()->implements_interface(method_holder) , "this class should implement the interface");
501 assert(is_miranda(m, ik()->methods(), ik()->super()), "should be a miranda_method");
502 return true;
503 }
504 return false;
505 }
507 // check if a method is a miranda method, given a class's methods table and it's super
508 // the caller must make sure that the method belongs to an interface implemented by the class
509 bool klassVtable::is_miranda(methodOop m, objArrayOop class_methods, klassOop super) {
510 symbolOop name = m->name();
511 symbolOop signature = m->signature();
512 if (instanceKlass::find_method(class_methods, name, signature) == NULL) {
513 // did not find it in the method table of the current class
514 if (super == NULL) {
515 // super doesn't exist
516 return true;
517 } else {
518 if (instanceKlass::cast(super)->lookup_method(name, signature) == NULL) {
519 // super class hierarchy does not implement it
520 return true;
521 }
522 }
523 }
524 return false;
525 }
527 void klassVtable::add_new_mirandas_to_list(GrowableArray<methodOop>* list_of_current_mirandas,
528 objArrayOop current_interface_methods,
529 objArrayOop class_methods,
530 klassOop super) {
531 // iterate thru the current interface's method to see if it a miranda
532 int num_methods = current_interface_methods->length();
533 for (int i = 0; i < num_methods; i++) {
534 methodOop im = methodOop(current_interface_methods->obj_at(i));
535 bool is_duplicate = false;
536 int num_of_current_mirandas = list_of_current_mirandas->length();
537 // check for duplicate mirandas in different interfaces we implement
538 for (int j = 0; j < num_of_current_mirandas; j++) {
539 methodOop miranda = list_of_current_mirandas->at(j);
540 if ((im->name() == miranda->name()) &&
541 (im->signature() == miranda->signature())) {
542 is_duplicate = true;
543 break;
544 }
545 }
547 if (!is_duplicate) { // we don't want duplicate miranda entries in the vtable
548 if (is_miranda(im, class_methods, super)) { // is it a miranda at all?
549 instanceKlass *sk = instanceKlass::cast(super);
550 // check if it is a duplicate of a super's miranda
551 if (sk->lookup_method_in_all_interfaces(im->name(), im->signature()) == NULL) {
552 list_of_current_mirandas->append(im);
553 }
554 }
555 }
556 }
557 }
559 void klassVtable::get_mirandas(GrowableArray<methodOop>* mirandas,
560 klassOop super, objArrayOop class_methods,
561 objArrayOop local_interfaces) {
562 assert((mirandas->length() == 0) , "current mirandas must be 0");
564 // iterate thru the local interfaces looking for a miranda
565 int num_local_ifs = local_interfaces->length();
566 for (int i = 0; i < num_local_ifs; i++) {
567 instanceKlass *ik = instanceKlass::cast(klassOop(local_interfaces->obj_at(i)));
568 add_new_mirandas_to_list(mirandas, ik->methods(), class_methods, super);
569 // iterate thru each local's super interfaces
570 objArrayOop super_ifs = ik->transitive_interfaces();
571 int num_super_ifs = super_ifs->length();
572 for (int j = 0; j < num_super_ifs; j++) {
573 instanceKlass *sik = instanceKlass::cast(klassOop(super_ifs->obj_at(j)));
574 add_new_mirandas_to_list(mirandas, sik->methods(), class_methods, super);
575 }
576 }
577 }
579 // get number of mirandas
580 int klassVtable::get_num_mirandas(klassOop super, objArrayOop class_methods, objArrayOop local_interfaces) {
581 ResourceMark rm;
582 GrowableArray<methodOop>* mirandas = new GrowableArray<methodOop>(20);
583 get_mirandas(mirandas, super, class_methods, local_interfaces);
584 return mirandas->length();
585 }
587 // fill in mirandas
588 void klassVtable::fill_in_mirandas(int& initialized) {
589 ResourceMark rm;
590 GrowableArray<methodOop>* mirandas = new GrowableArray<methodOop>(20);
591 instanceKlass *this_ik = ik();
592 get_mirandas(mirandas, this_ik->super(), this_ik->methods(), this_ik->local_interfaces());
593 int num_mirandas = mirandas->length();
594 for (int i = 0; i < num_mirandas; i++) {
595 put_method_at(mirandas->at(i), initialized);
596 initialized++;
597 }
598 }
600 void klassVtable::copy_vtable_to(vtableEntry* start) {
601 Copy::disjoint_words((HeapWord*)table(), (HeapWord*)start, _length * vtableEntry::size());
602 }
604 void klassVtable::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
605 int methods_length, bool * trace_name_printed) {
606 // search the vtable for uses of either obsolete or EMCP methods
607 for (int j = 0; j < methods_length; j++) {
608 methodOop old_method = old_methods[j];
609 methodOop new_method = new_methods[j];
611 // In the vast majority of cases we could get the vtable index
612 // by using: old_method->vtable_index()
613 // However, there are rare cases, eg. sun.awt.X11.XDecoratedPeer.getX()
614 // in sun.awt.X11.XFramePeer where methods occur more than once in the
615 // vtable, so, alas, we must do an exhaustive search.
616 for (int index = 0; index < length(); index++) {
617 if (unchecked_method_at(index) == old_method) {
618 put_method_at(new_method, index);
620 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
621 if (!(*trace_name_printed)) {
622 // RC_TRACE_MESG macro has an embedded ResourceMark
623 RC_TRACE_MESG(("adjust: name=%s",
624 Klass::cast(old_method->method_holder())->external_name()));
625 *trace_name_printed = true;
626 }
627 // RC_TRACE macro has an embedded ResourceMark
628 RC_TRACE(0x00100000, ("vtable method update: %s(%s)",
629 new_method->name()->as_C_string(),
630 new_method->signature()->as_C_string()));
631 }
632 }
633 }
634 }
635 }
638 // Garbage collection
639 void klassVtable::oop_follow_contents() {
640 int len = length();
641 for (int i = 0; i < len; i++) {
642 MarkSweep::mark_and_push(adr_method_at(i));
643 }
644 }
646 #ifndef SERIALGC
647 void klassVtable::oop_follow_contents(ParCompactionManager* cm) {
648 int len = length();
649 for (int i = 0; i < len; i++) {
650 PSParallelCompact::mark_and_push(cm, adr_method_at(i));
651 }
652 }
653 #endif // SERIALGC
655 void klassVtable::oop_adjust_pointers() {
656 int len = length();
657 for (int i = 0; i < len; i++) {
658 MarkSweep::adjust_pointer(adr_method_at(i));
659 }
660 }
662 #ifndef SERIALGC
663 void klassVtable::oop_update_pointers(ParCompactionManager* cm) {
664 const int n = length();
665 for (int i = 0; i < n; i++) {
666 PSParallelCompact::adjust_pointer(adr_method_at(i));
667 }
668 }
670 void klassVtable::oop_update_pointers(ParCompactionManager* cm,
671 HeapWord* beg_addr, HeapWord* end_addr) {
672 const int n = length();
673 const int entry_size = vtableEntry::size();
675 int beg_idx = 0;
676 HeapWord* const method_0 = (HeapWord*)adr_method_at(0);
677 if (beg_addr > method_0) {
678 // it's safe to use cast, as we have guarantees on vtable size to be sane
679 beg_idx = int((pointer_delta(beg_addr, method_0) + entry_size - 1) / entry_size);
680 }
682 oop* const beg_oop = adr_method_at(beg_idx);
683 oop* const end_oop = MIN2((oop*)end_addr, adr_method_at(n));
684 for (oop* cur_oop = beg_oop; cur_oop < end_oop; cur_oop += entry_size) {
685 PSParallelCompact::adjust_pointer(cur_oop);
686 }
687 }
688 #endif // SERIALGC
690 // Iterators
691 void klassVtable::oop_oop_iterate(OopClosure* blk) {
692 int len = length();
693 for (int i = 0; i < len; i++) {
694 blk->do_oop(adr_method_at(i));
695 }
696 }
698 void klassVtable::oop_oop_iterate_m(OopClosure* blk, MemRegion mr) {
699 int len = length();
700 int i;
701 for (i = 0; i < len; i++) {
702 if ((HeapWord*)adr_method_at(i) >= mr.start()) break;
703 }
704 for (; i < len; i++) {
705 oop* adr = adr_method_at(i);
706 if ((HeapWord*)adr < mr.end()) blk->do_oop(adr);
707 }
708 }
710 //-----------------------------------------------------------------------------------------
711 // Itable code
713 // Initialize a itableMethodEntry
714 void itableMethodEntry::initialize(methodOop m) {
715 if (m == NULL) return;
717 _method = m;
718 }
720 klassItable::klassItable(instanceKlassHandle klass) {
721 _klass = klass;
723 if (klass->itable_length() > 0) {
724 itableOffsetEntry* offset_entry = (itableOffsetEntry*)klass->start_of_itable();
725 if (offset_entry != NULL && offset_entry->interface_klass() != NULL) { // Check that itable is initialized
726 // First offset entry points to the first method_entry
727 intptr_t* method_entry = (intptr_t *)(((address)klass->as_klassOop()) + offset_entry->offset());
728 intptr_t* end = klass->end_of_itable();
730 _table_offset = (intptr_t*)offset_entry - (intptr_t*)klass->as_klassOop();
731 _size_offset_table = (method_entry - ((intptr_t*)offset_entry)) / itableOffsetEntry::size();
732 _size_method_table = (end - method_entry) / itableMethodEntry::size();
733 assert(_table_offset >= 0 && _size_offset_table >= 0 && _size_method_table >= 0, "wrong computation");
734 return;
735 }
736 }
738 // The length of the itable was either zero, or it has not yet been initialized.
739 _table_offset = 0;
740 _size_offset_table = 0;
741 _size_method_table = 0;
742 }
744 // Garbage Collection
746 void klassItable::oop_follow_contents() {
747 // offset table
748 itableOffsetEntry* ioe = offset_entry(0);
749 for(int i = 0; i < _size_offset_table; i++) {
750 MarkSweep::mark_and_push((oop*)&ioe->_interface);
751 ioe++;
752 }
754 // method table
755 itableMethodEntry* ime = method_entry(0);
756 for(int j = 0; j < _size_method_table; j++) {
757 MarkSweep::mark_and_push((oop*)&ime->_method);
758 ime++;
759 }
760 }
762 #ifndef SERIALGC
763 void klassItable::oop_follow_contents(ParCompactionManager* cm) {
764 // offset table
765 itableOffsetEntry* ioe = offset_entry(0);
766 for(int i = 0; i < _size_offset_table; i++) {
767 PSParallelCompact::mark_and_push(cm, (oop*)&ioe->_interface);
768 ioe++;
769 }
771 // method table
772 itableMethodEntry* ime = method_entry(0);
773 for(int j = 0; j < _size_method_table; j++) {
774 PSParallelCompact::mark_and_push(cm, (oop*)&ime->_method);
775 ime++;
776 }
777 }
778 #endif // SERIALGC
780 void klassItable::oop_adjust_pointers() {
781 // offset table
782 itableOffsetEntry* ioe = offset_entry(0);
783 for(int i = 0; i < _size_offset_table; i++) {
784 MarkSweep::adjust_pointer((oop*)&ioe->_interface);
785 ioe++;
786 }
788 // method table
789 itableMethodEntry* ime = method_entry(0);
790 for(int j = 0; j < _size_method_table; j++) {
791 MarkSweep::adjust_pointer((oop*)&ime->_method);
792 ime++;
793 }
794 }
796 #ifndef SERIALGC
797 void klassItable::oop_update_pointers(ParCompactionManager* cm) {
798 // offset table
799 itableOffsetEntry* ioe = offset_entry(0);
800 for(int i = 0; i < _size_offset_table; i++) {
801 PSParallelCompact::adjust_pointer((oop*)&ioe->_interface);
802 ioe++;
803 }
805 // method table
806 itableMethodEntry* ime = method_entry(0);
807 for(int j = 0; j < _size_method_table; j++) {
808 PSParallelCompact::adjust_pointer((oop*)&ime->_method);
809 ime++;
810 }
811 }
813 void klassItable::oop_update_pointers(ParCompactionManager* cm,
814 HeapWord* beg_addr, HeapWord* end_addr) {
815 // offset table
816 itableOffsetEntry* ioe = offset_entry(0);
817 for(int i = 0; i < _size_offset_table; i++) {
818 oop* p = (oop*)&ioe->_interface;
819 PSParallelCompact::adjust_pointer(p, beg_addr, end_addr);
820 ioe++;
821 }
823 // method table
824 itableMethodEntry* ime = method_entry(0);
825 for(int j = 0; j < _size_method_table; j++) {
826 oop* p = (oop*)&ime->_method;
827 PSParallelCompact::adjust_pointer(p, beg_addr, end_addr);
828 ime++;
829 }
830 }
831 #endif // SERIALGC
833 // Iterators
834 void klassItable::oop_oop_iterate(OopClosure* blk) {
835 // offset table
836 itableOffsetEntry* ioe = offset_entry(0);
837 for(int i = 0; i < _size_offset_table; i++) {
838 blk->do_oop((oop*)&ioe->_interface);
839 ioe++;
840 }
842 // method table
843 itableMethodEntry* ime = method_entry(0);
844 for(int j = 0; j < _size_method_table; j++) {
845 blk->do_oop((oop*)&ime->_method);
846 ime++;
847 }
848 }
850 void klassItable::oop_oop_iterate_m(OopClosure* blk, MemRegion mr) {
851 // offset table
852 itableOffsetEntry* ioe = offset_entry(0);
853 for(int i = 0; i < _size_offset_table; i++) {
854 oop* adr = (oop*)&ioe->_interface;
855 if (mr.contains(adr)) blk->do_oop(adr);
856 ioe++;
857 }
859 // method table
860 itableMethodEntry* ime = method_entry(0);
861 for(int j = 0; j < _size_method_table; j++) {
862 oop* adr = (oop*)&ime->_method;
863 if (mr.contains(adr)) blk->do_oop(adr);
864 ime++;
865 }
866 }
869 static int initialize_count = 0;
871 // Initialization
872 void klassItable::initialize_itable(bool checkconstraints, TRAPS) {
873 // Cannot be setup doing bootstrapping, interfaces don't have
874 // itables, and klass with only ones entry have empty itables
875 if (Universe::is_bootstrapping() ||
876 _klass->is_interface() ||
877 _klass->itable_length() == itableOffsetEntry::size()) return;
879 // There's alway an extra itable entry so we can null-terminate it.
880 guarantee(size_offset_table() >= 1, "too small");
881 int num_interfaces = size_offset_table() - 1;
882 if (num_interfaces > 0) {
883 if (TraceItables) tty->print_cr("%3d: Initializing itables for %s", ++initialize_count,
884 _klass->name()->as_C_string());
887 // Interate through all interfaces
888 int i;
889 for(i = 0; i < num_interfaces; i++) {
890 itableOffsetEntry* ioe = offset_entry(i);
891 KlassHandle interf_h (THREAD, ioe->interface_klass());
892 assert(interf_h() != NULL && ioe->offset() != 0, "bad offset entry in itable");
893 initialize_itable_for_interface(ioe->offset(), interf_h, checkconstraints, CHECK);
894 }
896 }
897 // Check that the last entry is empty
898 itableOffsetEntry* ioe = offset_entry(size_offset_table() - 1);
899 guarantee(ioe->interface_klass() == NULL && ioe->offset() == 0, "terminator entry missing");
900 }
903 void klassItable::initialize_itable_for_interface(int method_table_offset, KlassHandle interf_h, bool checkconstraints, TRAPS) {
904 objArrayHandle methods(THREAD, instanceKlass::cast(interf_h())->methods());
905 int nof_methods = methods()->length();
906 HandleMark hm;
907 KlassHandle klass = _klass;
908 assert(nof_methods > 0, "at least one method must exist for interface to be in vtable")
909 Handle interface_loader (THREAD, instanceKlass::cast(interf_h())->class_loader());
910 int ime_num = 0;
912 // Skip first methodOop if it is a class initializer
913 int i = ((methodOop)methods()->obj_at(0))->name() != vmSymbols::class_initializer_name() ? 0 : 1;
915 // m, method_name, method_signature, klass reset each loop so they
916 // don't need preserving across check_signature_loaders call
917 // methods needs a handle in case of gc from check_signature_loaders
918 for(; i < nof_methods; i++) {
919 methodOop m = (methodOop)methods()->obj_at(i);
920 symbolOop method_name = m->name();
921 symbolOop method_signature = m->signature();
923 // This is same code as in Linkresolver::lookup_instance_method_in_klasses
924 methodOop target = klass->uncached_lookup_method(method_name, method_signature);
925 while (target != NULL && target->is_static()) {
926 // continue with recursive lookup through the superclass
927 klassOop super = Klass::cast(target->method_holder())->super();
928 target = (super == NULL) ? methodOop(NULL) : Klass::cast(super)->uncached_lookup_method(method_name, method_signature);
929 }
930 if (target == NULL || !target->is_public() || target->is_abstract()) {
931 // Entry do not resolve. Leave it empty
932 } else {
933 // Entry did resolve, check loader constraints before initializing
934 // if checkconstraints requested
935 methodHandle target_h (THREAD, target); // preserve across gc
936 if (checkconstraints) {
937 Handle method_holder_loader (THREAD, instanceKlass::cast(target->method_holder())->class_loader());
938 if (method_holder_loader() != interface_loader()) {
939 ResourceMark rm(THREAD);
940 char* failed_type_name =
941 SystemDictionary::check_signature_loaders(method_signature,
942 method_holder_loader,
943 interface_loader,
944 true, CHECK);
945 if (failed_type_name != NULL) {
946 const char* msg = "loader constraint violation in interface "
947 "itable initialization: when resolving method \"%s\" the class"
948 " loader (instance of %s) of the current class, %s, "
949 "and the class loader (instance of %s) for interface "
950 "%s have different Class objects for the type %s "
951 "used in the signature";
952 char* sig = target_h()->name_and_sig_as_C_string();
953 const char* loader1 = SystemDictionary::loader_name(method_holder_loader());
954 char* current = klass->name()->as_C_string();
955 const char* loader2 = SystemDictionary::loader_name(interface_loader());
956 char* iface = instanceKlass::cast(interf_h())->name()->as_C_string();
957 size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) +
958 strlen(current) + strlen(loader2) + strlen(iface) +
959 strlen(failed_type_name);
960 char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
961 jio_snprintf(buf, buflen, msg, sig, loader1, current, loader2,
962 iface, failed_type_name);
963 THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
964 }
965 }
966 }
968 // ime may have moved during GC so recalculate address
969 itableOffsetEntry::method_entry(_klass(), method_table_offset)[ime_num].initialize(target_h());
970 }
971 // Progress to next entry
972 ime_num++;
973 }
974 }
976 // Update entry for specific methodOop
977 void klassItable::initialize_with_method(methodOop m) {
978 itableMethodEntry* ime = method_entry(0);
979 for(int i = 0; i < _size_method_table; i++) {
980 if (ime->method() == m) {
981 ime->initialize(m);
982 }
983 ime++;
984 }
985 }
987 void klassItable::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
988 int methods_length, bool * trace_name_printed) {
989 // search the itable for uses of either obsolete or EMCP methods
990 for (int j = 0; j < methods_length; j++) {
991 methodOop old_method = old_methods[j];
992 methodOop new_method = new_methods[j];
993 itableMethodEntry* ime = method_entry(0);
995 // The itable can describe more than one interface and the same
996 // method signature can be specified by more than one interface.
997 // This means we have to do an exhaustive search to find all the
998 // old_method references.
999 for (int i = 0; i < _size_method_table; i++) {
1000 if (ime->method() == old_method) {
1001 ime->initialize(new_method);
1003 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
1004 if (!(*trace_name_printed)) {
1005 // RC_TRACE_MESG macro has an embedded ResourceMark
1006 RC_TRACE_MESG(("adjust: name=%s",
1007 Klass::cast(old_method->method_holder())->external_name()));
1008 *trace_name_printed = true;
1009 }
1010 // RC_TRACE macro has an embedded ResourceMark
1011 RC_TRACE(0x00200000, ("itable method update: %s(%s)",
1012 new_method->name()->as_C_string(),
1013 new_method->signature()->as_C_string()));
1014 }
1015 }
1016 ime++;
1017 }
1018 }
1019 }
1022 // Setup
1023 class InterfaceVisiterClosure : public StackObj {
1024 public:
1025 virtual void doit(klassOop intf, int method_count) = 0;
1026 };
1028 // Visit all interfaces with at-least one method (excluding <clinit>)
1029 void visit_all_interfaces(objArrayOop transitive_intf, InterfaceVisiterClosure *blk) {
1030 // Handle array argument
1031 for(int i = 0; i < transitive_intf->length(); i++) {
1032 klassOop intf = (klassOop)transitive_intf->obj_at(i);
1033 assert(Klass::cast(intf)->is_interface(), "sanity check");
1035 // Find no. of methods excluding a <clinit>
1036 int method_count = instanceKlass::cast(intf)->methods()->length();
1037 if (method_count > 0) {
1038 methodOop m = (methodOop)instanceKlass::cast(intf)->methods()->obj_at(0);
1039 assert(m != NULL && m->is_method(), "sanity check");
1040 if (m->name() == vmSymbols::object_initializer_name()) {
1041 method_count--;
1042 }
1043 }
1045 // Only count interfaces with at least one method
1046 if (method_count > 0) {
1047 blk->doit(intf, method_count);
1048 }
1049 }
1050 }
1052 class CountInterfacesClosure : public InterfaceVisiterClosure {
1053 private:
1054 int _nof_methods;
1055 int _nof_interfaces;
1056 public:
1057 CountInterfacesClosure() { _nof_methods = 0; _nof_interfaces = 0; }
1059 int nof_methods() const { return _nof_methods; }
1060 int nof_interfaces() const { return _nof_interfaces; }
1062 void doit(klassOop intf, int method_count) { _nof_methods += method_count; _nof_interfaces++; }
1063 };
1065 class SetupItableClosure : public InterfaceVisiterClosure {
1066 private:
1067 itableOffsetEntry* _offset_entry;
1068 itableMethodEntry* _method_entry;
1069 address _klass_begin;
1070 public:
1071 SetupItableClosure(address klass_begin, itableOffsetEntry* offset_entry, itableMethodEntry* method_entry) {
1072 _klass_begin = klass_begin;
1073 _offset_entry = offset_entry;
1074 _method_entry = method_entry;
1075 }
1077 itableMethodEntry* method_entry() const { return _method_entry; }
1079 void doit(klassOop intf, int method_count) {
1080 int offset = ((address)_method_entry) - _klass_begin;
1081 _offset_entry->initialize(intf, offset);
1082 _offset_entry++;
1083 _method_entry += method_count;
1084 }
1085 };
1087 int klassItable::compute_itable_size(objArrayHandle transitive_interfaces) {
1088 // Count no of interfaces and total number of interface methods
1089 CountInterfacesClosure cic;
1090 visit_all_interfaces(transitive_interfaces(), &cic);
1092 // There's alway an extra itable entry so we can null-terminate it.
1093 int itable_size = calc_itable_size(cic.nof_interfaces() + 1, cic.nof_methods());
1095 // Statistics
1096 update_stats(itable_size * HeapWordSize);
1098 return itable_size;
1099 }
1102 // Fill out offset table and interface klasses into the itable space
1103 void klassItable::setup_itable_offset_table(instanceKlassHandle klass) {
1104 if (klass->itable_length() == 0) return;
1105 assert(!klass->is_interface(), "Should have zero length itable");
1107 // Count no of interfaces and total number of interface methods
1108 CountInterfacesClosure cic;
1109 visit_all_interfaces(klass->transitive_interfaces(), &cic);
1110 int nof_methods = cic.nof_methods();
1111 int nof_interfaces = cic.nof_interfaces();
1113 // Add one extra entry so we can null-terminate the table
1114 nof_interfaces++;
1116 assert(compute_itable_size(objArrayHandle(klass->transitive_interfaces())) ==
1117 calc_itable_size(nof_interfaces, nof_methods),
1118 "mismatch calculation of itable size");
1120 // Fill-out offset table
1121 itableOffsetEntry* ioe = (itableOffsetEntry*)klass->start_of_itable();
1122 itableMethodEntry* ime = (itableMethodEntry*)(ioe + nof_interfaces);
1123 intptr_t* end = klass->end_of_itable();
1124 assert((oop*)(ime + nof_methods) <= (oop*)klass->start_of_static_fields(), "wrong offset calculation (1)");
1125 assert((oop*)(end) == (oop*)(ime + nof_methods), "wrong offset calculation (2)");
1127 // Visit all interfaces and initialize itable offset table
1128 SetupItableClosure sic((address)klass->as_klassOop(), ioe, ime);
1129 visit_all_interfaces(klass->transitive_interfaces(), &sic);
1131 #ifdef ASSERT
1132 ime = sic.method_entry();
1133 oop* v = (oop*) klass->end_of_itable();
1134 assert( (oop*)(ime) == v, "wrong offset calculation (2)");
1135 #endif
1136 }
1139 // m must be a method in an interface
1140 int klassItable::compute_itable_index(methodOop m) {
1141 klassOop intf = m->method_holder();
1142 assert(instanceKlass::cast(intf)->is_interface(), "sanity check");
1143 objArrayOop methods = instanceKlass::cast(intf)->methods();
1144 int index = 0;
1145 while(methods->obj_at(index) != m) {
1146 index++;
1147 assert(index < methods->length(), "should find index for resolve_invoke");
1148 }
1149 // Adjust for <clinit>, which is left out of table if first method
1150 if (methods->length() > 0 && ((methodOop)methods->obj_at(0))->name() == vmSymbols::class_initializer_name()) {
1151 index--;
1152 }
1153 return index;
1154 }
1157 // inverse to compute_itable_index
1158 methodOop klassItable::method_for_itable_index(klassOop intf, int itable_index) {
1159 assert(instanceKlass::cast(intf)->is_interface(), "sanity check");
1160 objArrayOop methods = instanceKlass::cast(intf)->methods();
1162 int index = itable_index;
1163 // Adjust for <clinit>, which is left out of table if first method
1164 if (methods->length() > 0 && ((methodOop)methods->obj_at(0))->name() == vmSymbols::class_initializer_name()) {
1165 index++;
1166 }
1168 if (itable_index < 0 || index >= methods->length())
1169 return NULL; // help caller defend against bad indexes
1171 methodOop m = (methodOop)methods->obj_at(index);
1172 assert(compute_itable_index(m) == itable_index, "correct inverse");
1174 return m;
1175 }
1177 void klassVtable::verify(outputStream* st, bool forced) {
1178 // make sure table is initialized
1179 if (!Universe::is_fully_initialized()) return;
1180 #ifndef PRODUCT
1181 // avoid redundant verifies
1182 if (!forced && _verify_count == Universe::verify_count()) return;
1183 _verify_count = Universe::verify_count();
1184 #endif
1185 oop* end_of_obj = (oop*)_klass() + _klass()->size();
1186 oop* end_of_vtable = (oop *)&table()[_length];
1187 if (end_of_vtable > end_of_obj) {
1188 fatal1("klass %s: klass object too short (vtable extends beyond end)",
1189 _klass->internal_name());
1190 }
1192 for (int i = 0; i < _length; i++) table()[i].verify(this, st);
1193 // verify consistency with superKlass vtable
1194 klassOop super = _klass->super();
1195 if (super != NULL) {
1196 instanceKlass* sk = instanceKlass::cast(super);
1197 klassVtable* vt = sk->vtable();
1198 for (int i = 0; i < vt->length(); i++) {
1199 verify_against(st, vt, i);
1200 }
1201 }
1202 }
1204 void klassVtable::verify_against(outputStream* st, klassVtable* vt, int index) {
1205 vtableEntry* vte = &vt->table()[index];
1206 if (vte->method()->name() != table()[index].method()->name() ||
1207 vte->method()->signature() != table()[index].method()->signature()) {
1208 fatal("mismatched name/signature of vtable entries");
1209 }
1210 }
1212 #ifndef PRODUCT
1213 void klassVtable::print() {
1214 ResourceMark rm;
1215 tty->print("klassVtable for klass %s (length %d):\n", _klass->internal_name(), length());
1216 for (int i = 0; i < length(); i++) {
1217 table()[i].print();
1218 tty->cr();
1219 }
1220 }
1221 #endif
1223 void vtableEntry::verify(klassVtable* vt, outputStream* st) {
1224 NOT_PRODUCT(FlagSetting fs(IgnoreLockingAssertions, true));
1225 assert(method() != NULL, "must have set method");
1226 method()->verify();
1227 // we sub_type, because it could be a miranda method
1228 if (!vt->klass()->is_subtype_of(method()->method_holder())) {
1229 #ifndef PRODUCT
1230 print();
1231 #endif
1232 fatal1("vtableEntry %#lx: method is from subclass", this);
1233 }
1234 }
1236 #ifndef PRODUCT
1238 void vtableEntry::print() {
1239 ResourceMark rm;
1240 tty->print("vtableEntry %s: ", method()->name()->as_C_string());
1241 if (Verbose) {
1242 tty->print("m %#lx ", (address)method());
1243 }
1244 }
1246 class VtableStats : AllStatic {
1247 public:
1248 static int no_klasses; // # classes with vtables
1249 static int no_array_klasses; // # array classes
1250 static int no_instance_klasses; // # instanceKlasses
1251 static int sum_of_vtable_len; // total # of vtable entries
1252 static int sum_of_array_vtable_len; // total # of vtable entries in array klasses only
1253 static int fixed; // total fixed overhead in bytes
1254 static int filler; // overhead caused by filler bytes
1255 static int entries; // total bytes consumed by vtable entries
1256 static int array_entries; // total bytes consumed by array vtable entries
1258 static void do_class(klassOop k) {
1259 Klass* kl = k->klass_part();
1260 klassVtable* vt = kl->vtable();
1261 if (vt == NULL) return;
1262 no_klasses++;
1263 if (kl->oop_is_instance()) {
1264 no_instance_klasses++;
1265 kl->array_klasses_do(do_class);
1266 }
1267 if (kl->oop_is_array()) {
1268 no_array_klasses++;
1269 sum_of_array_vtable_len += vt->length();
1270 }
1271 sum_of_vtable_len += vt->length();
1272 }
1274 static void compute() {
1275 SystemDictionary::classes_do(do_class);
1276 fixed = no_klasses * oopSize; // vtable length
1277 // filler size is a conservative approximation
1278 filler = oopSize * (no_klasses - no_instance_klasses) * (sizeof(instanceKlass) - sizeof(arrayKlass) - 1);
1279 entries = sizeof(vtableEntry) * sum_of_vtable_len;
1280 array_entries = sizeof(vtableEntry) * sum_of_array_vtable_len;
1281 }
1282 };
1284 int VtableStats::no_klasses = 0;
1285 int VtableStats::no_array_klasses = 0;
1286 int VtableStats::no_instance_klasses = 0;
1287 int VtableStats::sum_of_vtable_len = 0;
1288 int VtableStats::sum_of_array_vtable_len = 0;
1289 int VtableStats::fixed = 0;
1290 int VtableStats::filler = 0;
1291 int VtableStats::entries = 0;
1292 int VtableStats::array_entries = 0;
1294 void klassVtable::print_statistics() {
1295 ResourceMark rm;
1296 HandleMark hm;
1297 VtableStats::compute();
1298 tty->print_cr("vtable statistics:");
1299 tty->print_cr("%6d classes (%d instance, %d array)", VtableStats::no_klasses, VtableStats::no_instance_klasses, VtableStats::no_array_klasses);
1300 int total = VtableStats::fixed + VtableStats::filler + VtableStats::entries;
1301 tty->print_cr("%6d bytes fixed overhead (refs + vtable object header)", VtableStats::fixed);
1302 tty->print_cr("%6d bytes filler overhead", VtableStats::filler);
1303 tty->print_cr("%6d bytes for vtable entries (%d for arrays)", VtableStats::entries, VtableStats::array_entries);
1304 tty->print_cr("%6d bytes total", total);
1305 }
1307 bool klassVtable::check_no_old_entries() {
1308 // Check that there really is no entry
1309 for (int i = 0; i < length(); i++) {
1310 methodOop m = unchecked_method_at(i);
1311 if (m != NULL) {
1312 if (m->is_old()) {
1313 return false;
1314 }
1315 }
1316 }
1317 return true;
1318 }
1320 void klassVtable::dump_vtable() {
1321 tty->print_cr("vtable dump --");
1322 for (int i = 0; i < length(); i++) {
1323 methodOop m = unchecked_method_at(i);
1324 if (m != NULL) {
1325 tty->print(" (%5d) ", i);
1326 m->access_flags().print_on(tty);
1327 tty->print(" -- ");
1328 m->print_name(tty);
1329 tty->cr();
1330 }
1331 }
1332 }
1334 int klassItable::_total_classes; // Total no. of classes with itables
1335 long klassItable::_total_size; // Total no. of bytes used for itables
1337 void klassItable::print_statistics() {
1338 tty->print_cr("itable statistics:");
1339 tty->print_cr("%6d classes with itables", _total_classes);
1340 tty->print_cr("%6d K uses for itables (average by class: %d bytes)", _total_size / K, _total_size / _total_classes);
1341 }
1343 #endif // PRODUCT