1 /* 2 * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "gc_implementation/shared/markSweep.inline.hpp" 27 #include "interpreter/interpreter.hpp" 28 #include "interpreter/rewriter.hpp" 29 #include "memory/universe.inline.hpp" 30 #include "oops/cpCache.hpp" 31 #include "oops/objArrayOop.hpp" 32 #include "oops/oop.inline.hpp" 33 #include "prims/jvmtiRedefineClassesTrace.hpp" 34 #include "prims/methodHandles.hpp" 35 #include "runtime/handles.inline.hpp" 36 #ifndef SERIALGC 37 # include "gc_implementation/parallelScavenge/psPromotionManager.hpp" 38 #endif 39 40 41 // Implememtation of ConstantPoolCacheEntry 42 43 void ConstantPoolCacheEntry::initialize_entry(int index) { 44 assert(0 < index && index < 0x10000, "sanity check"); 45 _indices = index; 46 assert(constant_pool_index() == index, ""); 47 } 48 49 int ConstantPoolCacheEntry::make_flags(TosState state, 50 int option_bits, 51 int field_index_or_method_params) { 52 assert(state < number_of_states, "Invalid state in make_flags"); 53 int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params; 54 // Preserve existing flag bit values 55 // The low bits are a field offset, or else the method parameter size. 56 #ifdef ASSERT 57 TosState old_state = flag_state(); 58 assert(old_state == (TosState)0 || old_state == state, 59 "inconsistent cpCache flags state"); 60 #endif 61 return (_flags | f) ; 62 } 63 64 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) { 65 #ifdef ASSERT 66 // Read once. 67 volatile Bytecodes::Code c = bytecode_1(); 68 assert(c == 0 || c == code || code == 0, "update must be consistent"); 69 #endif 70 // Need to flush pending stores here before bytecode is written. 71 OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_1_shift)); 72 } 73 74 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) { 75 #ifdef ASSERT 76 // Read once. 77 volatile Bytecodes::Code c = bytecode_2(); 78 assert(c == 0 || c == code || code == 0, "update must be consistent"); 79 #endif 80 // Need to flush pending stores here before bytecode is written. 81 OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_2_shift)); 82 } 83 84 // Sets f1, ordering with previous writes. 85 void ConstantPoolCacheEntry::release_set_f1(Metadata* f1) { 86 assert(f1 != NULL, ""); 87 OrderAccess::release_store_ptr((HeapWord*) &_f1, f1); 88 } 89 90 // Sets flags, but only if the value was previously zero. 91 bool ConstantPoolCacheEntry::init_flags_atomic(intptr_t flags) { 92 intptr_t result = Atomic::cmpxchg_ptr(flags, &_flags, 0); 93 return (result == 0); 94 } 95 96 // Note that concurrent update of both bytecodes can leave one of them 97 // reset to zero. This is harmless; the interpreter will simply re-resolve 98 // the damaged entry. More seriously, the memory synchronization is needed 99 // to flush other fields (f1, f2) completely to memory before the bytecodes 100 // are updated, lest other processors see a non-zero bytecode but zero f1/f2. 101 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code, 102 Bytecodes::Code put_code, 103 KlassHandle field_holder, 104 int field_index, 105 int field_offset, 106 TosState field_type, 107 bool is_final, 108 bool is_volatile, 109 Klass* root_klass) { 110 set_f1(field_holder()); 111 set_f2(field_offset); 112 assert((field_index & field_index_mask) == field_index, 113 "field index does not fit in low flag bits"); 114 set_field_flags(field_type, 115 ((is_volatile ? 1 : 0) << is_volatile_shift) | 116 ((is_final ? 1 : 0) << is_final_shift), 117 field_index); 118 set_bytecode_1(get_code); 119 set_bytecode_2(put_code); 120 NOT_PRODUCT(verify(tty)); 121 } 122 123 void ConstantPoolCacheEntry::set_parameter_size(int value) { 124 // This routine is called only in corner cases where the CPCE is not yet initialized. 125 // See AbstractInterpreter::deopt_continue_after_entry. 126 assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value, 127 err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value)); 128 // Setting the parameter size by itself is only safe if the 129 // current value of _flags is 0, otherwise another thread may have 130 // updated it and we don't want to overwrite that value. Don't 131 // bother trying to update it once it's nonzero but always make 132 // sure that the final parameter size agrees with what was passed. 133 if (_flags == 0) { 134 Atomic::cmpxchg_ptr((value & parameter_size_mask), &_flags, 0); 135 } 136 guarantee(parameter_size() == value, 137 err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value)); 138 } 139 140 void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code, 141 methodHandle method, 142 int vtable_index) { 143 assert(method->interpreter_entry() != NULL, "should have been set at this point"); 144 assert(!method->is_obsolete(), "attempt to write obsolete method to cpCache"); 145 146 int byte_no = -1; 147 bool change_to_virtual = false; 148 149 switch (invoke_code) { 150 case Bytecodes::_invokeinterface: 151 // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface 152 // instruction somehow links to a non-interface method (in Object). 153 // In that case, the method has no itable index and must be invoked as a virtual. 154 // Set a flag to keep track of this corner case. 155 change_to_virtual = true; 156 157 // ...and fall through as if we were handling invokevirtual: 158 case Bytecodes::_invokevirtual: 159 { 160 if (method->can_be_statically_bound()) { 161 // set_f2_as_vfinal_method checks if is_vfinal flag is true. 162 set_method_flags(as_TosState(method->result_type()), 163 ( 1 << is_vfinal_shift) | 164 ((method->is_final_method() ? 1 : 0) << is_final_shift) | 165 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift), 166 method()->size_of_parameters()); 167 set_f2_as_vfinal_method(method()); 168 } else { 169 assert(vtable_index >= 0, "valid index"); 170 assert(!method->is_final_method(), "sanity"); 171 set_method_flags(as_TosState(method->result_type()), 172 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift), 173 method()->size_of_parameters()); 174 set_f2(vtable_index); 175 } 176 byte_no = 2; 177 break; 178 } 179 180 case Bytecodes::_invokespecial: 181 case Bytecodes::_invokestatic: 182 // Note: Read and preserve the value of the is_vfinal flag on any 183 // invokevirtual bytecode shared with this constant pool cache entry. 184 // It is cheap and safe to consult is_vfinal() at all times. 185 // Once is_vfinal is set, it must stay that way, lest we get a dangling oop. 186 set_method_flags(as_TosState(method->result_type()), 187 ((is_vfinal() ? 1 : 0) << is_vfinal_shift) | 188 ((method->is_final_method() ? 1 : 0) << is_final_shift), 189 method()->size_of_parameters()); 190 set_f1(method()); 191 byte_no = 1; 192 break; 193 default: 194 ShouldNotReachHere(); 195 break; 196 } 197 198 // Note: byte_no also appears in TemplateTable::resolve. 199 if (byte_no == 1) { 200 assert(invoke_code != Bytecodes::_invokevirtual && 201 invoke_code != Bytecodes::_invokeinterface, ""); 202 set_bytecode_1(invoke_code); 203 } else if (byte_no == 2) { 204 if (change_to_virtual) { 205 assert(invoke_code == Bytecodes::_invokeinterface, ""); 206 // NOTE: THIS IS A HACK - BE VERY CAREFUL!!! 207 // 208 // Workaround for the case where we encounter an invokeinterface, but we 209 // should really have an _invokevirtual since the resolved method is a 210 // virtual method in java.lang.Object. This is a corner case in the spec 211 // but is presumably legal. javac does not generate this code. 212 // 213 // We set bytecode_1() to _invokeinterface, because that is the 214 // bytecode # used by the interpreter to see if it is resolved. 215 // We set bytecode_2() to _invokevirtual. 216 // See also interpreterRuntime.cpp. (8/25/2000) 217 // Only set resolved for the invokeinterface case if method is public. 218 // Otherwise, the method needs to be reresolved with caller for each 219 // interface call. 220 if (method->is_public()) set_bytecode_1(invoke_code); 221 } else { 222 assert(invoke_code == Bytecodes::_invokevirtual, ""); 223 } 224 // set up for invokevirtual, even if linking for invokeinterface also: 225 set_bytecode_2(Bytecodes::_invokevirtual); 226 } else { 227 ShouldNotReachHere(); 228 } 229 NOT_PRODUCT(verify(tty)); 230 } 231 232 233 void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) { 234 InstanceKlass* interf = method->method_holder(); 235 assert(interf->is_interface(), "must be an interface"); 236 assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here"); 237 set_f1(interf); 238 set_f2(index); 239 set_method_flags(as_TosState(method->result_type()), 240 0, // no option bits 241 method()->size_of_parameters()); 242 set_bytecode_1(Bytecodes::_invokeinterface); 243 } 244 245 246 void ConstantPoolCacheEntry::set_method_handle(constantPoolHandle cpool, const CallInfo &call_info) { 247 set_method_handle_common(cpool, Bytecodes::_invokehandle, call_info); 248 } 249 250 void ConstantPoolCacheEntry::set_dynamic_call(constantPoolHandle cpool, const CallInfo &call_info) { 251 set_method_handle_common(cpool, Bytecodes::_invokedynamic, call_info); 252 } 253 254 void ConstantPoolCacheEntry::set_method_handle_common(constantPoolHandle cpool, 255 Bytecodes::Code invoke_code, 256 const CallInfo &call_info) { 257 // NOTE: This CPCE can be the subject of data races. 258 // There are three words to update: flags, refs[f2], f1 (in that order). 259 // Writers must store all other values before f1. 260 // Readers must test f1 first for non-null before reading other fields. 261 // Competing writers must acquire exclusive access via a lock. 262 // A losing writer waits on the lock until the winner writes f1 and leaves 263 // the lock, so that when the losing writer returns, he can use the linked 264 // cache entry. 265 266 MonitorLockerEx ml(cpool->lock()); 267 if (!is_f1_null()) { 268 return; 269 } 270 271 const methodHandle adapter = call_info.resolved_method(); 272 const Handle appendix = call_info.resolved_appendix(); 273 const Handle method_type = call_info.resolved_method_type(); 274 const bool has_appendix = appendix.not_null(); 275 const bool has_method_type = method_type.not_null(); 276 277 // Write the flags. 278 set_method_flags(as_TosState(adapter->result_type()), 279 ((has_appendix ? 1 : 0) << has_appendix_shift ) | 280 ((has_method_type ? 1 : 0) << has_method_type_shift) | 281 ( 1 << is_final_shift ), 282 adapter->size_of_parameters()); 283 284 if (TraceInvokeDynamic) { 285 tty->print_cr("set_method_handle bc=%d appendix="PTR_FORMAT"%s method_type="PTR_FORMAT"%s method="PTR_FORMAT" ", 286 invoke_code, 287 (intptr_t)appendix(), (has_appendix ? "" : " (unused)"), 288 (intptr_t)method_type(), (has_method_type ? "" : " (unused)"), 289 (intptr_t)adapter()); 290 adapter->print(); 291 if (has_appendix) appendix()->print(); 292 } 293 294 // Method handle invokes and invokedynamic sites use both cp cache words. 295 // refs[f2], if not null, contains a value passed as a trailing argument to the adapter. 296 // In the general case, this could be the call site's MethodType, 297 // for use with java.lang.Invokers.checkExactType, or else a CallSite object. 298 // f1 contains the adapter method which manages the actual call. 299 // In the general case, this is a compiled LambdaForm. 300 // (The Java code is free to optimize these calls by binding other 301 // sorts of methods and appendices to call sites.) 302 // JVM-level linking is via f1, as if for invokespecial, and signatures are erased. 303 // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits. 304 // Even with the appendix, the method will never take more than 255 parameter slots. 305 // 306 // This means that given a call site like (List)mh.invoke("foo"), 307 // the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;', 308 // not '(Ljava/lang/String;)Ljava/util/List;'. 309 // The fact that String and List are involved is encoded in the MethodType in refs[f2]. 310 // This allows us to create fewer method oops, while keeping type safety. 311 // 312 313 objArrayHandle resolved_references = cpool->resolved_references(); 314 // Store appendix, if any. 315 if (has_appendix) { 316 const int appendix_index = f2_as_index() + _indy_resolved_references_appendix_offset; 317 assert(appendix_index >= 0 && appendix_index < resolved_references->length(), "oob"); 318 assert(resolved_references->obj_at(appendix_index) == NULL, "init just once"); 319 resolved_references->obj_at_put(appendix_index, appendix()); 320 } 321 322 // Store MethodType, if any. 323 if (has_method_type) { 324 const int method_type_index = f2_as_index() + _indy_resolved_references_method_type_offset; 325 assert(method_type_index >= 0 && method_type_index < resolved_references->length(), "oob"); 326 assert(resolved_references->obj_at(method_type_index) == NULL, "init just once"); 327 resolved_references->obj_at_put(method_type_index, method_type()); 328 } 329 330 release_set_f1(adapter()); // This must be the last one to set (see NOTE above)! 331 332 // The interpreter assembly code does not check byte_2, 333 // but it is used by is_resolved, method_if_resolved, etc. 334 set_bytecode_1(invoke_code); 335 NOT_PRODUCT(verify(tty)); 336 if (TraceInvokeDynamic) { 337 this->print(tty, 0); 338 } 339 } 340 341 Method* ConstantPoolCacheEntry::method_if_resolved(constantPoolHandle cpool) { 342 // Decode the action of set_method and set_interface_call 343 Bytecodes::Code invoke_code = bytecode_1(); 344 if (invoke_code != (Bytecodes::Code)0) { 345 Metadata* f1 = (Metadata*)_f1; 346 if (f1 != NULL) { 347 switch (invoke_code) { 348 case Bytecodes::_invokeinterface: 349 assert(f1->is_klass(), ""); 350 return klassItable::method_for_itable_index((Klass*)f1, f2_as_index()); 351 case Bytecodes::_invokestatic: 352 case Bytecodes::_invokespecial: 353 assert(!has_appendix(), ""); 354 case Bytecodes::_invokehandle: 355 case Bytecodes::_invokedynamic: 356 assert(f1->is_method(), ""); 357 return (Method*)f1; 358 } 359 } 360 } 361 invoke_code = bytecode_2(); 362 if (invoke_code != (Bytecodes::Code)0) { 363 switch (invoke_code) { 364 case Bytecodes::_invokevirtual: 365 if (is_vfinal()) { 366 // invokevirtual 367 Method* m = f2_as_vfinal_method(); 368 assert(m->is_method(), ""); 369 return m; 370 } else { 371 int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index()); 372 if (cpool->tag_at(holder_index).is_klass()) { 373 Klass* klass = cpool->resolved_klass_at(holder_index); 374 if (!klass->oop_is_instance()) 375 klass = SystemDictionary::Object_klass(); 376 return InstanceKlass::cast(klass)->method_at_vtable(f2_as_index()); 377 } 378 } 379 break; 380 } 381 } 382 return NULL; 383 } 384 385 386 oop ConstantPoolCacheEntry::appendix_if_resolved(constantPoolHandle cpool) { 387 if (is_f1_null() || !has_appendix()) 388 return NULL; 389 const int ref_index = f2_as_index() + _indy_resolved_references_appendix_offset; 390 objArrayOop resolved_references = cpool->resolved_references(); 391 return resolved_references->obj_at(ref_index); 392 } 393 394 395 oop ConstantPoolCacheEntry::method_type_if_resolved(constantPoolHandle cpool) { 396 if (is_f1_null() || !has_method_type()) 397 return NULL; 398 const int ref_index = f2_as_index() + _indy_resolved_references_method_type_offset; 399 objArrayOop resolved_references = cpool->resolved_references(); 400 return resolved_references->obj_at(ref_index); 401 } 402 403 404 #if INCLUDE_JVMTI 405 // RedefineClasses() API support: 406 // If this ConstantPoolCacheEntry refers to old_method then update it 407 // to refer to new_method. 408 bool ConstantPoolCacheEntry::adjust_method_entry(Method* old_method, 409 Method* new_method, bool * trace_name_printed) { 410 411 if (is_vfinal()) { 412 // virtual and final so _f2 contains method ptr instead of vtable index 413 if (f2_as_vfinal_method() == old_method) { 414 // match old_method so need an update 415 // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values 416 _f2 = (intptr_t)new_method; 417 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) { 418 if (!(*trace_name_printed)) { 419 // RC_TRACE_MESG macro has an embedded ResourceMark 420 RC_TRACE_MESG(("adjust: name=%s", 421 old_method->method_holder()->external_name())); 422 *trace_name_printed = true; 423 } 424 // RC_TRACE macro has an embedded ResourceMark 425 RC_TRACE(0x00400000, ("cpc vf-entry update: %s(%s)", 426 new_method->name()->as_C_string(), 427 new_method->signature()->as_C_string())); 428 } 429 430 return true; 431 } 432 433 // f1() is not used with virtual entries so bail out 434 return false; 435 } 436 437 if (_f1 == NULL) { 438 // NULL f1() means this is a virtual entry so bail out 439 // We are assuming that the vtable index does not need change. 440 return false; 441 } 442 443 if (_f1 == old_method) { 444 _f1 = new_method; 445 if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) { 446 if (!(*trace_name_printed)) { 447 // RC_TRACE_MESG macro has an embedded ResourceMark 448 RC_TRACE_MESG(("adjust: name=%s", 449 old_method->method_holder()->external_name())); 450 *trace_name_printed = true; 451 } 452 // RC_TRACE macro has an embedded ResourceMark 453 RC_TRACE(0x00400000, ("cpc entry update: %s(%s)", 454 new_method->name()->as_C_string(), 455 new_method->signature()->as_C_string())); 456 } 457 458 return true; 459 } 460 461 return false; 462 } 463 464 // a constant pool cache entry should never contain old or obsolete methods 465 bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() { 466 if (is_vfinal()) { 467 // virtual and final so _f2 contains method ptr instead of vtable index 468 Metadata* f2 = (Metadata*)_f2; 469 // Return false if _f2 refers to an old or an obsolete method. 470 // _f2 == NULL || !_f2->is_method() are just as unexpected here. 471 return (f2 != NULL NOT_PRODUCT(&& f2->is_valid()) && f2->is_method() && 472 !((Method*)f2)->is_old() && !((Method*)f2)->is_obsolete()); 473 } else if (_f1 == NULL || 474 (NOT_PRODUCT(_f1->is_valid() &&) !_f1->is_method())) { 475 // _f1 == NULL || !_f1->is_method() are OK here 476 return true; 477 } 478 // return false if _f1 refers to an old or an obsolete method 479 return (NOT_PRODUCT(_f1->is_valid() &&) _f1->is_method() && 480 !((Method*)_f1)->is_old() && !((Method*)_f1)->is_obsolete()); 481 } 482 483 bool ConstantPoolCacheEntry::is_interesting_method_entry(Klass* k) { 484 if (!is_method_entry()) { 485 // not a method entry so not interesting by default 486 return false; 487 } 488 489 Method* m = NULL; 490 if (is_vfinal()) { 491 // virtual and final so _f2 contains method ptr instead of vtable index 492 m = f2_as_vfinal_method(); 493 } else if (is_f1_null()) { 494 // NULL _f1 means this is a virtual entry so also not interesting 495 return false; 496 } else { 497 if (!(_f1->is_method())) { 498 // _f1 can also contain a Klass* for an interface 499 return false; 500 } 501 m = f1_as_method(); 502 } 503 504 assert(m != NULL && m->is_method(), "sanity check"); 505 if (m == NULL || !m->is_method() || (k != NULL && m->method_holder() != k)) { 506 // robustness for above sanity checks or method is not in 507 // the interesting class 508 return false; 509 } 510 511 // the method is in the interesting class so the entry is interesting 512 return true; 513 } 514 #endif // INCLUDE_JVMTI 515 516 void ConstantPoolCacheEntry::print(outputStream* st, int index) const { 517 // print separator 518 if (index == 0) st->print_cr(" -------------"); 519 // print entry 520 st->print("%3d ("PTR_FORMAT") ", index, (intptr_t)this); 521 st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(), 522 constant_pool_index()); 523 st->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_f1); 524 st->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_f2); 525 st->print_cr(" [ "PTR_FORMAT"]", (intptr_t)_flags); 526 st->print_cr(" -------------"); 527 } 528 529 void ConstantPoolCacheEntry::verify(outputStream* st) const { 530 // not implemented yet 531 } 532 533 // Implementation of ConstantPoolCache 534 535 ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data, int length, TRAPS) { 536 int size = ConstantPoolCache::size(length); 537 538 return new (loader_data, size, false, THREAD) ConstantPoolCache(length); 539 } 540 541 void ConstantPoolCache::initialize(intArray& inverse_index_map, intArray& invokedynamic_references_map) { 542 assert(inverse_index_map.length() == length(), "inverse index map must have same length as cache"); 543 for (int i = 0; i < length(); i++) { 544 ConstantPoolCacheEntry* e = entry_at(i); 545 int original_index = inverse_index_map[i]; 546 e->initialize_entry(original_index); 547 assert(entry_at(i) == e, "sanity"); 548 } 549 for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) { 550 const int cpci = invokedynamic_references_map[ref]; 551 if (cpci >= 0) { 552 #ifdef ASSERT 553 // invokedynamic and invokehandle have more entries; check if they 554 // all point to the same constant pool cache entry. 555 for (int entry = 1; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) { 556 const int cpci_next = invokedynamic_references_map[ref + entry]; 557 assert(cpci == cpci_next, err_msg_res("%d == %d", cpci, cpci_next)); 558 } 559 #endif 560 entry_at(cpci)->initialize_resolved_reference_index(ref); 561 ref += ConstantPoolCacheEntry::_indy_resolved_references_entries - 1; // skip extra entries 562 } 563 } 564 } 565 566 #if INCLUDE_JVMTI 567 // RedefineClasses() API support: 568 // If any entry of this ConstantPoolCache points to any of 569 // old_methods, replace it with the corresponding new_method. 570 void ConstantPoolCache::adjust_method_entries(Method** old_methods, Method** new_methods, 571 int methods_length, bool * trace_name_printed) { 572 573 if (methods_length == 0) { 574 // nothing to do if there are no methods 575 return; 576 } 577 578 // get shorthand for the interesting class 579 Klass* old_holder = old_methods[0]->method_holder(); 580 581 for (int i = 0; i < length(); i++) { 582 if (!entry_at(i)->is_interesting_method_entry(old_holder)) { 583 // skip uninteresting methods 584 continue; 585 } 586 587 // The ConstantPoolCache contains entries for several different 588 // things, but we only care about methods. In fact, we only care 589 // about methods in the same class as the one that contains the 590 // old_methods. At this point, we have an interesting entry. 591 592 for (int j = 0; j < methods_length; j++) { 593 Method* old_method = old_methods[j]; 594 Method* new_method = new_methods[j]; 595 596 if (entry_at(i)->adjust_method_entry(old_method, new_method, 597 trace_name_printed)) { 598 // current old_method matched this entry and we updated it so 599 // break out and get to the next interesting entry if there one 600 break; 601 } 602 } 603 } 604 } 605 606 // the constant pool cache should never contain old or obsolete methods 607 bool ConstantPoolCache::check_no_old_or_obsolete_entries() { 608 for (int i = 1; i < length(); i++) { 609 if (entry_at(i)->is_interesting_method_entry(NULL) && 610 !entry_at(i)->check_no_old_or_obsolete_entries()) { 611 return false; 612 } 613 } 614 return true; 615 } 616 617 void ConstantPoolCache::dump_cache() { 618 for (int i = 1; i < length(); i++) { 619 if (entry_at(i)->is_interesting_method_entry(NULL)) { 620 entry_at(i)->print(tty, i); 621 } 622 } 623 } 624 #endif // INCLUDE_JVMTI 625 626 627 // Printing 628 629 void ConstantPoolCache::print_on(outputStream* st) const { 630 assert(is_constantPoolCache(), "obj must be constant pool cache"); 631 st->print_cr(internal_name()); 632 // print constant pool cache entries 633 for (int i = 0; i < length(); i++) entry_at(i)->print(st, i); 634 } 635 636 void ConstantPoolCache::print_value_on(outputStream* st) const { 637 assert(is_constantPoolCache(), "obj must be constant pool cache"); 638 st->print("cache [%d]", length()); 639 print_address_on(st); 640 st->print(" for "); 641 constant_pool()->print_value_on(st); 642 } 643 644 645 // Verification 646 647 void ConstantPoolCache::verify_on(outputStream* st) { 648 guarantee(is_constantPoolCache(), "obj must be constant pool cache"); 649 // print constant pool cache entries 650 for (int i = 0; i < length(); i++) entry_at(i)->verify(st); 651 }