klassVtable.cpp revision 0:a61af66fc99e
152419Sjulian/* 252419Sjulian * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved. 352419Sjulian * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4164676Sru * 5164676Sru * This code is free software; you can redistribute it and/or modify it 680029Sobrien * under the terms of the GNU General Public License version 2 only, as 780029Sobrien * published by the Free Software Foundation. 8124271Sgreen * 989674Sarchie * This code is distributed in the hope that it will be useful, but WITHOUT 10125011Sru * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11161044Sglebius * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12168041Sglebius * version 2 for more details (a copy is included in the LICENSE file that 13161044Sglebius * accompanied this code). 14161044Sglebius * 15161044Sglebius * You should have received a copy of the GNU General Public License version 16177714Sru * 2 along with this work; if not, write to the Free Software Foundation, 17164676Sru * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18164676Sru * 19164676Sru * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 2080029Sobrien * CA 95054 USA or visit www.sun.com if you need additional information or 2180029Sobrien * have any questions. 2280029Sobrien * 23161044Sglebius */ 24161044Sglebius 25161044Sglebius#include "incls/_precompiled.incl" 26164618Sru#include "incls/_klassVtable.cpp.incl" 27161044Sglebius 28161044Sglebiusinline instanceKlass* klassVtable::ik() const { 2952419Sjulian 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. 43void 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 ) { 52 53 No_Safepoint_Verifier nsv; 54 55 // set up default result values 56 vtable_length = 0; 57 num_miranda_methods = 0; 58 59 // start off with super's vtable length 60 instanceKlass* sk = (instanceKlass*)super->klass_part(); 61 vtable_length = super == NULL ? 0 : sk->vtable_length(); 62 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)); 68 69 if (needs_new_vtable_entry(m, super, classloader, classname, class_flags)) { 70 vtable_length += vtableEntry::size(); // we need a new entry 71 } 72 } 73 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()); 77 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 } 83 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} 98 99int 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} 103 104int 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} 126 127// Revised lookup semantics introduced 1.3 (Kestral beta) 128void klassVtable::initialize_vtable(bool checkconstraints, TRAPS) { 129 130 // Note: Arrays can have intermediate array supers. Use java_super to skip them. 131 KlassHandle super (THREAD, klass()->java_super()); 132 int nofNewEntries = 0; 133 134 135 if (PrintVtables && !klass()->oop_is_array()) { 136 ResourceMark rm(THREAD); 137 tty->print_cr("Initializing: %s", _klass->name()->as_C_string()); 138 } 139 140#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 145 146 if (Universe::is_bootstrapping()) { 147 // just clear everything 148 for (int i = 0; i < _length; i++) table()[i].clear(); 149 return; 150 } 151 152 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"); 157 158 objArrayHandle methods(THREAD, ik()->methods()); 159 int len = methods()->length(); 160 int initialized = super_vtable_len; 161 162 // 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)); 167 168 bool needs_new_entry = update_super_vtable(ik(), mh, super_vtable_len, checkconstraints, CHECK); 169 170 if (needs_new_entry) { 171 put_method_at(mh(), initialized); 172 mh()->set_vtable_index(initialized); // set primary vtable index 173 initialized++; 174 } 175 } 176 177 // add miranda methods; it will also update the value of initialized 178 fill_in_mirandas(initialized); 179 180 // 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} 190 191// 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. 194klassVtable::AccessType klassVtable::vtable_accessibility_at(int i) { 195 // This vtable is not implementing the specific method 196 if (i >= length()) return acc_private; 197 198 // 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; 201 202 AccessType acc = m->is_package_private() ? acc_package_private : acc_private; 203 204 // 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; 208 209 // Merge 210 return (AccessType)MAX2((int)acc, (int)super_acc); 211} 212 213 214// 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 218bool 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"); 222 223 // 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); 226 227 // Static and <init> methods are never in 228 if (target_method()->is_static() || target_method()->name() == vmSymbols::object_initializer_name()) { 229 return false; 230 } 231 232 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 } 238 239 // we need a new entry if there is no superclass 240 if (klass->super() == NULL) { 241 return allocate_new; 242 } 243 244 // private methods always have a new entry in the vtable 245 if (target_method()->is_private()) { 246 return allocate_new; 247 } 248 249 // 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 255 256 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()) { 262 263 instanceKlass* holder = (THREAD, instanceKlass::cast(match_method->method_holder())); 264 265 // Check if the match_method is accessable from current class 266 267 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()); 273 274 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; 290 291 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 } 297 298 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()); 309 310 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); 336 337 338 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} 380 381 382 383void 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} 394 395// 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. 401bool 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 } 417 418 // we need a new entry if there is no superclass 419 if (super == NULL) { 420 return true; 421 } 422 423 // private methods always have a new entry in the vtable 424 if (target_method->is_private()) { 425 return true; 426 } 427 428 // 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()); 443 444 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 } 450 451 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 } 458 459 k = holder->super(); // haven't found a match yet; continue to look 460 } 461 462 // 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 } 472 473 return true; // found no match; we need a new entry 474} 475 476// Support for miranda methods 477 478// get the vtable index of a miranda method with matching "name" and "signature" 479int 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} 490 491// check if an entry is miranda 492bool 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); 496 497 // 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} 506 507// 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 509bool 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} 526 527void 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 } 546 547 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} 558 559void 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"); 563 564 // 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} 578 579// get number of mirandas 580int 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} 586 587// fill in mirandas 588void 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} 599 600void klassVtable::copy_vtable_to(vtableEntry* start) { 601 Copy::disjoint_words((HeapWord*)table(), (HeapWord*)start, _length * vtableEntry::size()); 602} 603 604void 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]; 610 611 // 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); 619 620 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} 636 637 638// Garbage collection 639void 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} 645 646#ifndef SERIALGC 647void 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 654 655void 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} 661 662#ifndef SERIALGC 663void 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} 669 670void 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(); 674 675 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 } 681 682 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 689 690// Iterators 691void 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} 697 698void 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} 709 710//----------------------------------------------------------------------------------------- 711// Itable code 712 713// Initialize a itableMethodEntry 714void itableMethodEntry::initialize(methodOop m) { 715 if (m == NULL) return; 716 717 _method = m; 718} 719 720klassItable::klassItable(instanceKlassHandle klass) { 721 _klass = klass; 722 723 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(); 729 730 _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 } 737 738 // This lenght 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} 743 744// Garbage Collection 745 746void 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 } 753 754 // 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} 761 762#ifndef SERIALGC 763void 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 } 770 771 // 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 779 780void 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 } 787 788 // 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} 795 796#ifndef SERIALGC 797void 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 } 804 805 // 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} 812 813void 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 } 822 823 // 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 832 833// Iterators 834void 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 } 841 842 // 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} 849 850void 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 } 858 859 // 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} 867 868 869static int initialize_count = 0; 870 871// Initialization 872void klassItable::initialize_itable(bool checkconstraints, TRAPS) { 873 // Cannot be setup doing bootstrapping 874 if (Universe::is_bootstrapping()) return; 875 876 int num_interfaces = nof_interfaces(); 877 if (num_interfaces > 0) { 878 if (TraceItables) tty->print_cr("%3d: Initializing itables for %s", ++initialize_count, _klass->name()->as_C_string()); 879 880 // In debug mode, we got an extra NULL/NULL entry 881 debug_only(num_interfaces--); 882 assert(num_interfaces > 0, "to few interfaces in offset itable"); 883 884 // Interate through all interfaces 885 int i; 886 for(i = 0; i < num_interfaces; i++) { 887 itableOffsetEntry* ioe = offset_entry(i); 888 KlassHandle interf_h (THREAD, ioe->interface_klass()); 889 assert(interf_h() != NULL && ioe->offset() != 0, "bad offset entry in itable"); 890 initialize_itable_for_interface(ioe->offset(), interf_h, checkconstraints, CHECK); 891 } 892 893#ifdef ASSERT 894 // Check that the last entry is empty 895 itableOffsetEntry* ioe = offset_entry(i); 896 assert(ioe->interface_klass() == NULL && ioe->offset() == 0, "terminator entry missing"); 897#endif 898 } 899} 900 901 902void klassItable::initialize_itable_for_interface(int method_table_offset, KlassHandle interf_h, bool checkconstraints, TRAPS) { 903 objArrayHandle methods(THREAD, instanceKlass::cast(interf_h())->methods()); 904 int nof_methods = methods()->length(); 905 HandleMark hm; 906 KlassHandle klass = _klass; 907 assert(nof_methods > 0, "at least one method must exist for interface to be in vtable") 908 Handle interface_loader (THREAD, instanceKlass::cast(interf_h())->class_loader()); 909 int ime_num = 0; 910 911 // Skip first methodOop if it is a class initializer 912 int i = ((methodOop)methods()->obj_at(0))->name() != vmSymbols::class_initializer_name() ? 0 : 1; 913 914 // m, method_name, method_signature, klass reset each loop so they 915 // don't need preserving across check_signature_loaders call 916 // methods needs a handle in case of gc from check_signature_loaders 917 for(; i < nof_methods; i++) { 918 methodOop m = (methodOop)methods()->obj_at(i); 919 symbolOop method_name = m->name(); 920 symbolOop method_signature = m->signature(); 921 922 // This is same code as in Linkresolver::lookup_instance_method_in_klasses 923 methodOop target = klass->uncached_lookup_method(method_name, method_signature); 924 while (target != NULL && target->is_static()) { 925 // continue with recursive lookup through the superclass 926 klassOop super = Klass::cast(target->method_holder())->super(); 927 target = (super == NULL) ? methodOop(NULL) : Klass::cast(super)->uncached_lookup_method(method_name, method_signature); 928 } 929 if (target == NULL || !target->is_public() || target->is_abstract()) { 930 // Entry do not resolve. Leave it empty 931 } else { 932 // Entry did resolve, check loader constraints before initializing 933 // if checkconstraints requested 934 methodHandle target_h (THREAD, target); // preserve across gc 935 if (checkconstraints) { 936 Handle method_holder_loader (THREAD, instanceKlass::cast(target->method_holder())->class_loader()); 937 if (method_holder_loader() != interface_loader()) { 938 ResourceMark rm(THREAD); 939 char* failed_type_name = 940 SystemDictionary::check_signature_loaders(method_signature, 941 method_holder_loader, 942 interface_loader, 943 true, CHECK); 944 if (failed_type_name != NULL) { 945 const char* msg = "loader constraint violation in interface " 946 "itable initialization: when resolving method \"%s\" the class" 947 " loader (instance of %s) of the current class, %s, " 948 "and the class loader (instance of %s) for interface " 949 "%s have different Class objects for the type %s " 950 "used in the signature"; 951 char* sig = target_h()->name_and_sig_as_C_string(); 952 const char* loader1 = SystemDictionary::loader_name(method_holder_loader()); 953 char* current = klass->name()->as_C_string(); 954 const char* loader2 = SystemDictionary::loader_name(interface_loader()); 955 char* iface = instanceKlass::cast(interf_h())->name()->as_C_string(); 956 size_t buflen = strlen(msg) + strlen(sig) + strlen(loader1) + 957 strlen(current) + strlen(loader2) + strlen(iface) + 958 strlen(failed_type_name); 959 char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen); 960 jio_snprintf(buf, buflen, msg, sig, loader1, current, loader2, 961 iface, failed_type_name); 962 THROW_MSG(vmSymbols::java_lang_LinkageError(), buf); 963 } 964 } 965 } 966 967 // ime may have moved during GC so recalculate address 968 itableOffsetEntry::method_entry(_klass(), method_table_offset)[ime_num].initialize(target_h()); 969 } 970 // Progress to next entry 971 ime_num++; 972 } 973} 974 975// Update entry for specic methodOop 976void klassItable::initialize_with_method(methodOop m) { 977 itableMethodEntry* ime = method_entry(0); 978 for(int i = 0; i < _size_method_table; i++) { 979 if (ime->method() == m) { 980 ime->initialize(m); 981 } 982 ime++; 983 } 984} 985 986void klassItable::adjust_method_entries(methodOop* old_methods, methodOop* new_methods, 987 int methods_length, bool * trace_name_printed) { 988 // search the itable for uses of either obsolete or EMCP methods 989 for (int j = 0; j < methods_length; j++) { 990 methodOop old_method = old_methods[j]; 991 methodOop new_method = new_methods[j]; 992 itableMethodEntry* ime = method_entry(0); 993 994 for (int i = 0; i < _size_method_table; i++) { 995 if (ime->method() == old_method) { 996 ime->initialize(new_method); 997 998 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) { 999 if (!(*trace_name_printed)) { 1000 // RC_TRACE_MESG macro has an embedded ResourceMark 1001 RC_TRACE_MESG(("adjust: name=%s", 1002 Klass::cast(old_method->method_holder())->external_name())); 1003 *trace_name_printed = true; 1004 } 1005 // RC_TRACE macro has an embedded ResourceMark 1006 RC_TRACE(0x00200000, ("itable method update: %s(%s)", 1007 new_method->name()->as_C_string(), 1008 new_method->signature()->as_C_string())); 1009 } 1010 break; 1011 } 1012 ime++; 1013 } 1014 } 1015} 1016 1017 1018// Setup 1019class InterfaceVisiterClosure : public StackObj { 1020 public: 1021 virtual void doit(klassOop intf, int method_count) = 0; 1022}; 1023 1024// Visit all interfaces with at-least one method (excluding <clinit>) 1025void visit_all_interfaces(objArrayOop transitive_intf, InterfaceVisiterClosure *blk) { 1026 // Handle array argument 1027 for(int i = 0; i < transitive_intf->length(); i++) { 1028 klassOop intf = (klassOop)transitive_intf->obj_at(i); 1029 assert(Klass::cast(intf)->is_interface(), "sanity check"); 1030 1031 // Find no. of methods excluding a <clinit> 1032 int method_count = instanceKlass::cast(intf)->methods()->length(); 1033 if (method_count > 0) { 1034 methodOop m = (methodOop)instanceKlass::cast(intf)->methods()->obj_at(0); 1035 assert(m != NULL && m->is_method(), "sanity check"); 1036 if (m->name() == vmSymbols::object_initializer_name()) { 1037 method_count--; 1038 } 1039 } 1040 1041 // Only count interfaces with at least one method 1042 if (method_count > 0) { 1043 blk->doit(intf, method_count); 1044 } 1045 } 1046} 1047 1048class CountInterfacesClosure : public InterfaceVisiterClosure { 1049 private: 1050 int _nof_methods; 1051 int _nof_interfaces; 1052 public: 1053 CountInterfacesClosure() { _nof_methods = 0; _nof_interfaces = 0; } 1054 1055 int nof_methods() const { return _nof_methods; } 1056 int nof_interfaces() const { return _nof_interfaces; } 1057 1058 void doit(klassOop intf, int method_count) { _nof_methods += method_count; _nof_interfaces++; } 1059}; 1060 1061class SetupItableClosure : public InterfaceVisiterClosure { 1062 private: 1063 itableOffsetEntry* _offset_entry; 1064 itableMethodEntry* _method_entry; 1065 address _klass_begin; 1066 public: 1067 SetupItableClosure(address klass_begin, itableOffsetEntry* offset_entry, itableMethodEntry* method_entry) { 1068 _klass_begin = klass_begin; 1069 _offset_entry = offset_entry; 1070 _method_entry = method_entry; 1071 } 1072 1073 itableMethodEntry* method_entry() const { return _method_entry; } 1074 1075 void doit(klassOop intf, int method_count) { 1076 int offset = ((address)_method_entry) - _klass_begin; 1077 _offset_entry->initialize(intf, offset); 1078 _offset_entry++; 1079 _method_entry += method_count; 1080 } 1081}; 1082 1083int klassItable::compute_itable_size(objArrayHandle transitive_interfaces) { 1084 // Count no of interfaces and total number of interface methods 1085 CountInterfacesClosure cic; 1086 visit_all_interfaces(transitive_interfaces(), &cic); 1087 1088 // Add one extra entry in debug mode, so we can null-terminate the table 1089 int nof_methods = cic.nof_methods(); 1090 int nof_interfaces = cic.nof_interfaces(); 1091 debug_only(if (nof_interfaces > 0) nof_interfaces++); 1092 1093 int itable_size = calc_itable_size(nof_interfaces, nof_methods); 1094 1095 // Statistics 1096 update_stats(itable_size * HeapWordSize); 1097 1098 return itable_size; 1099} 1100 1101 1102// Fill out offset table and interface klasses into the itable space 1103void klassItable::setup_itable_offset_table(instanceKlassHandle klass) { 1104 if (klass->itable_length() == 0) return; 1105 assert(!klass->is_interface(), "Should have zero length itable"); 1106 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(); 1112 1113 // Add one extra entry in debug mode, so we can null-terminate the table 1114 debug_only(if (nof_interfaces > 0) nof_interfaces++); 1115 1116 assert(compute_itable_size(objArrayHandle(klass->transitive_interfaces())) == 1117 calc_itable_size(nof_interfaces, nof_methods), 1118 "mismatch calculation of itable size"); 1119 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) <= klass->start_of_static_fields(), "wrong offset calculation (1)"); 1125 assert((oop*)(end) == (oop*)(ime + nof_methods), "wrong offset calculation (2)"); 1126 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); 1130 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} 1137 1138 1139// m must be a method in an interface 1140int 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} 1155 1156void klassVtable::verify(outputStream* st, bool forced) { 1157 // make sure table is initialized 1158 if (!Universe::is_fully_initialized()) return; 1159#ifndef PRODUCT 1160 // avoid redundant verifies 1161 if (!forced && _verify_count == Universe::verify_count()) return; 1162 _verify_count = Universe::verify_count(); 1163#endif 1164 oop* end_of_obj = (oop*)_klass() + _klass()->size(); 1165 oop* end_of_vtable = (oop *)&table()[_length]; 1166 if (end_of_vtable > end_of_obj) { 1167 fatal1("klass %s: klass object too short (vtable extends beyond end)", 1168 _klass->internal_name()); 1169 } 1170 1171 for (int i = 0; i < _length; i++) table()[i].verify(this, st); 1172 // verify consistency with superKlass vtable 1173 klassOop super = _klass->super(); 1174 if (super != NULL) { 1175 instanceKlass* sk = instanceKlass::cast(super); 1176 klassVtable* vt = sk->vtable(); 1177 for (int i = 0; i < vt->length(); i++) { 1178 verify_against(st, vt, i); 1179 } 1180 } 1181} 1182 1183void klassVtable::verify_against(outputStream* st, klassVtable* vt, int index) { 1184 vtableEntry* vte = &vt->table()[index]; 1185 if (vte->method()->name() != table()[index].method()->name() || 1186 vte->method()->signature() != table()[index].method()->signature()) { 1187 fatal("mismatched name/signature of vtable entries"); 1188 } 1189} 1190 1191#ifndef PRODUCT 1192void klassVtable::print() { 1193 ResourceMark rm; 1194 tty->print("klassVtable for klass %s (length %d):\n", _klass->internal_name(), length()); 1195 for (int i = 0; i < length(); i++) { 1196 table()[i].print(); 1197 tty->cr(); 1198 } 1199} 1200#endif 1201 1202void vtableEntry::verify(klassVtable* vt, outputStream* st) { 1203 NOT_PRODUCT(FlagSetting fs(IgnoreLockingAssertions, true)); 1204 assert(method() != NULL, "must have set method"); 1205 method()->verify(); 1206 // we sub_type, because it could be a miranda method 1207 if (!vt->klass()->is_subtype_of(method()->method_holder())) { 1208#ifndef PRODUCT 1209 print(); 1210#endif 1211 fatal1("vtableEntry %#lx: method is from subclass", this); 1212 } 1213} 1214 1215#ifndef PRODUCT 1216 1217void vtableEntry::print() { 1218 ResourceMark rm; 1219 tty->print("vtableEntry %s: ", method()->name()->as_C_string()); 1220 if (Verbose) { 1221 tty->print("m %#lx ", (address)method()); 1222 } 1223} 1224 1225class VtableStats : AllStatic { 1226 public: 1227 static int no_klasses; // # classes with vtables 1228 static int no_array_klasses; // # array classes 1229 static int no_instance_klasses; // # instanceKlasses 1230 static int sum_of_vtable_len; // total # of vtable entries 1231 static int sum_of_array_vtable_len; // total # of vtable entries in array klasses only 1232 static int fixed; // total fixed overhead in bytes 1233 static int filler; // overhead caused by filler bytes 1234 static int entries; // total bytes consumed by vtable entries 1235 static int array_entries; // total bytes consumed by array vtable entries 1236 1237 static void do_class(klassOop k) { 1238 Klass* kl = k->klass_part(); 1239 klassVtable* vt = kl->vtable(); 1240 if (vt == NULL) return; 1241 no_klasses++; 1242 if (kl->oop_is_instance()) { 1243 no_instance_klasses++; 1244 kl->array_klasses_do(do_class); 1245 } 1246 if (kl->oop_is_array()) { 1247 no_array_klasses++; 1248 sum_of_array_vtable_len += vt->length(); 1249 } 1250 sum_of_vtable_len += vt->length(); 1251 } 1252 1253 static void compute() { 1254 SystemDictionary::classes_do(do_class); 1255 fixed = no_klasses * oopSize; // vtable length 1256 // filler size is a conservative approximation 1257 filler = oopSize * (no_klasses - no_instance_klasses) * (sizeof(instanceKlass) - sizeof(arrayKlass) - 1); 1258 entries = sizeof(vtableEntry) * sum_of_vtable_len; 1259 array_entries = sizeof(vtableEntry) * sum_of_array_vtable_len; 1260 } 1261}; 1262 1263int VtableStats::no_klasses = 0; 1264int VtableStats::no_array_klasses = 0; 1265int VtableStats::no_instance_klasses = 0; 1266int VtableStats::sum_of_vtable_len = 0; 1267int VtableStats::sum_of_array_vtable_len = 0; 1268int VtableStats::fixed = 0; 1269int VtableStats::filler = 0; 1270int VtableStats::entries = 0; 1271int VtableStats::array_entries = 0; 1272 1273void klassVtable::print_statistics() { 1274 ResourceMark rm; 1275 HandleMark hm; 1276 VtableStats::compute(); 1277 tty->print_cr("vtable statistics:"); 1278 tty->print_cr("%6d classes (%d instance, %d array)", VtableStats::no_klasses, VtableStats::no_instance_klasses, VtableStats::no_array_klasses); 1279 int total = VtableStats::fixed + VtableStats::filler + VtableStats::entries; 1280 tty->print_cr("%6d bytes fixed overhead (refs + vtable object header)", VtableStats::fixed); 1281 tty->print_cr("%6d bytes filler overhead", VtableStats::filler); 1282 tty->print_cr("%6d bytes for vtable entries (%d for arrays)", VtableStats::entries, VtableStats::array_entries); 1283 tty->print_cr("%6d bytes total", total); 1284} 1285 1286bool klassVtable::check_no_old_entries() { 1287 // Check that there really is no entry 1288 for (int i = 0; i < length(); i++) { 1289 methodOop m = unchecked_method_at(i); 1290 if (m != NULL) { 1291 if (m->is_old()) { 1292 return false; 1293 } 1294 } 1295 } 1296 return true; 1297} 1298 1299void klassVtable::dump_vtable() { 1300 tty->print_cr("vtable dump --"); 1301 for (int i = 0; i < length(); i++) { 1302 methodOop m = unchecked_method_at(i); 1303 if (m != NULL) { 1304 tty->print(" (%5d) ", i); 1305 m->access_flags().print_on(tty); 1306 tty->print(" -- "); 1307 m->print_name(tty); 1308 tty->cr(); 1309 } 1310 } 1311} 1312 1313int klassItable::_total_classes; // Total no. of classes with itables 1314long klassItable::_total_size; // Total no. of bytes used for itables 1315 1316void klassItable::print_statistics() { 1317 tty->print_cr("itable statistics:"); 1318 tty->print_cr("%6d classes with itables", _total_classes); 1319 tty->print_cr("%6d K uses for itables (average by class: %d bytes)", _total_size / K, _total_size / _total_classes); 1320} 1321 1322#endif // PRODUCT 1323