1 /* 2 * Copyright (c) 1998, 2021, 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 "cds/heapShared.hpp" 27 #include "classfile/resolutionErrors.hpp" 28 #include "classfile/systemDictionary.hpp" 29 #include "classfile/vmClasses.hpp" 30 #include "interpreter/bytecodeStream.hpp" 31 #include "interpreter/bytecodes.hpp" 32 #include "interpreter/interpreter.hpp" 33 #include "interpreter/linkResolver.hpp" 34 #include "interpreter/rewriter.hpp" 35 #include "logging/log.hpp" 36 #include "logging/logStream.hpp" 37 #include "memory/metadataFactory.hpp" 38 #include "memory/metaspaceClosure.hpp" 39 #include "memory/resourceArea.hpp" 40 #include "oops/access.inline.hpp" 41 #include "oops/compressedOops.hpp" 42 #include "oops/constantPool.inline.hpp" 43 #include "oops/cpCache.inline.hpp" 44 #include "oops/objArrayOop.inline.hpp" 45 #include "oops/oop.inline.hpp" 46 #include "prims/methodHandles.hpp" 47 #include "runtime/arguments.hpp" 48 #include "runtime/atomic.hpp" 49 #include "runtime/handles.inline.hpp" 50 #include "runtime/vm_version.hpp" 51 #include "utilities/macros.hpp" 52 53 // Implementation of ConstantPoolCacheEntry 54 55 void ConstantPoolCacheEntry::initialize_entry(int index) { 56 assert(0 < index && index < 0x10000, "sanity check"); 57 _indices = index; 58 _f1 = NULL; 59 _f2 = _flags = 0; 60 assert(constant_pool_index() == index, ""); 61 } 62 63 void ConstantPoolCacheEntry::verify_just_initialized(bool f2_used) { 64 assert((_indices & (~cp_index_mask)) == 0, "sanity"); 65 assert(_f1 == NULL, "sanity"); 66 assert(_flags == 0, "sanity"); 67 if (!f2_used) { 68 assert(_f2 == 0, "sanity"); 69 } 70 } 71 72 void ConstantPoolCacheEntry::reinitialize(bool f2_used) { 73 _indices &= cp_index_mask; 74 _f1 = NULL; 75 _flags = 0; 76 if (!f2_used) { 77 _f2 = 0; 78 } 79 } 80 81 int ConstantPoolCacheEntry::make_flags(TosState state, 82 int option_bits, 83 int field_index_or_method_params) { 84 assert(state < number_of_states, "Invalid state in make_flags"); 85 int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params; 86 // Preserve existing flag bit values 87 // The low bits are a field offset, or else the method parameter size. 88 #ifdef ASSERT 89 TosState old_state = flag_state(); 90 assert(old_state == (TosState)0 || old_state == state, 91 "inconsistent cpCache flags state"); 92 #endif 93 return (_flags | f) ; 94 } 95 96 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) { 97 #ifdef ASSERT 98 // Read once. 99 volatile Bytecodes::Code c = bytecode_1(); 100 assert(c == 0 || c == code || code == 0, "update must be consistent"); 101 #endif 102 // Need to flush pending stores here before bytecode is written. 103 Atomic::release_store(&_indices, _indices | ((u_char)code << bytecode_1_shift)); 104 } 105 106 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) { 107 #ifdef ASSERT 108 // Read once. 109 volatile Bytecodes::Code c = bytecode_2(); 110 assert(c == 0 || c == code || code == 0, "update must be consistent"); 111 #endif 112 // Need to flush pending stores here before bytecode is written. 113 Atomic::release_store(&_indices, _indices | ((u_char)code << bytecode_2_shift)); 114 } 115 116 // Sets f1, ordering with previous writes. 117 void ConstantPoolCacheEntry::release_set_f1(Metadata* f1) { 118 assert(f1 != NULL, ""); 119 Atomic::release_store(&_f1, f1); 120 } 121 122 void ConstantPoolCacheEntry::set_indy_resolution_failed() { 123 Atomic::release_store(&_flags, _flags | (1 << indy_resolution_failed_shift)); 124 } 125 126 // Note that concurrent update of both bytecodes can leave one of them 127 // reset to zero. This is harmless; the interpreter will simply re-resolve 128 // the damaged entry. More seriously, the memory synchronization is needed 129 // to flush other fields (f1, f2) completely to memory before the bytecodes 130 // are updated, lest other processors see a non-zero bytecode but zero f1/f2. 131 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code, 132 Bytecodes::Code put_code, 133 Klass* field_holder, 134 int field_index, 135 int field_offset, 136 TosState field_type, 137 bool is_final, 138 bool is_volatile, 139 bool is_inlined, 140 bool is_null_free_inline_type) { 141 set_f1(field_holder); 142 set_f2(field_offset); 143 assert((field_index & field_index_mask) == field_index, 144 "field index does not fit in low flag bits"); 145 assert(!is_inlined || is_null_free_inline_type, "Sanity check"); 146 set_field_flags(field_type, 147 ((is_volatile ? 1 : 0) << is_volatile_shift) | 148 ((is_final ? 1 : 0) << is_final_shift) | 149 ((is_inlined ? 1 : 0) << is_inlined_shift) | 150 ((is_null_free_inline_type ? 1 : 0) << is_null_free_inline_type_shift), 151 field_index); 152 set_bytecode_1(get_code); 153 set_bytecode_2(put_code); 154 NOT_PRODUCT(verify(tty)); 155 } 156 157 void ConstantPoolCacheEntry::set_parameter_size(int value) { 158 // This routine is called only in corner cases where the CPCE is not yet initialized. 159 // See AbstractInterpreter::deopt_continue_after_entry. 160 assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value, 161 "size must not change: parameter_size=%d, value=%d", parameter_size(), value); 162 // Setting the parameter size by itself is only safe if the 163 // current value of _flags is 0, otherwise another thread may have 164 // updated it and we don't want to overwrite that value. Don't 165 // bother trying to update it once it's nonzero but always make 166 // sure that the final parameter size agrees with what was passed. 167 if (_flags == 0) { 168 intx newflags = (value & parameter_size_mask); 169 Atomic::cmpxchg(&_flags, (intx)0, newflags); 170 } 171 guarantee(parameter_size() == value, 172 "size must not change: parameter_size=%d, value=%d", parameter_size(), value); 173 } 174 175 void ConstantPoolCacheEntry::set_direct_or_vtable_call(Bytecodes::Code invoke_code, 176 const methodHandle& method, 177 int vtable_index, 178 bool sender_is_interface) { 179 bool is_vtable_call = (vtable_index >= 0); // FIXME: split this method on this boolean 180 assert(method->interpreter_entry() != NULL, "should have been set at this point"); 181 assert(!method->is_obsolete(), "attempt to write obsolete method to cpCache"); 182 183 int byte_no = -1; 184 bool change_to_virtual = false; 185 InstanceKlass* holder = NULL; // have to declare this outside the switch 186 switch (invoke_code) { 187 case Bytecodes::_invokeinterface: 188 holder = method->method_holder(); 189 // check for private interface method invocations 190 if (vtable_index == Method::nonvirtual_vtable_index && holder->is_interface() ) { 191 assert(method->is_private(), "unexpected non-private method"); 192 assert(method->can_be_statically_bound(), "unexpected non-statically-bound method"); 193 // set_f2_as_vfinal_method checks if is_vfinal flag is true. 194 set_method_flags(as_TosState(method->result_type()), 195 ( 1 << is_vfinal_shift) | 196 ((method->is_final_method() ? 1 : 0) << is_final_shift), 197 method()->size_of_parameters()); 198 set_f2_as_vfinal_method(method()); 199 byte_no = 2; 200 set_f1(holder); // interface klass* 201 break; 202 } 203 else { 204 // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface 205 // instruction links to a non-interface method (in Object). This can happen when 206 // an interface redeclares an Object method (like CharSequence declaring toString()) 207 // or when invokeinterface is used explicitly. 208 // In that case, the method has no itable index and must be invoked as a virtual. 209 // Set a flag to keep track of this corner case. 210 assert(holder->is_interface() || holder == vmClasses::Object_klass(), "unexpected holder class"); 211 assert(method->is_public(), "Calling non-public method in Object with invokeinterface"); 212 change_to_virtual = true; 213 214 // ...and fall through as if we were handling invokevirtual: 215 } 216 case Bytecodes::_invokevirtual: 217 { 218 if (!is_vtable_call) { 219 assert(method->can_be_statically_bound(), ""); 220 // set_f2_as_vfinal_method checks if is_vfinal flag is true. 221 set_method_flags(as_TosState(method->result_type()), 222 ( 1 << is_vfinal_shift) | 223 ((method->is_final_method() ? 1 : 0) << is_final_shift) | 224 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift), 225 method()->size_of_parameters()); 226 set_f2_as_vfinal_method(method()); 227 } else { 228 assert(!method->can_be_statically_bound(), ""); 229 assert(vtable_index >= 0, "valid index"); 230 assert(!method->is_final_method(), "sanity"); 231 set_method_flags(as_TosState(method->result_type()), 232 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift), 233 method()->size_of_parameters()); 234 set_f2(vtable_index); 235 } 236 byte_no = 2; 237 break; 238 } 239 240 case Bytecodes::_invokespecial: 241 case Bytecodes::_invokestatic: 242 assert(!is_vtable_call, ""); 243 // Note: Read and preserve the value of the is_vfinal flag on any 244 // invokevirtual bytecode shared with this constant pool cache entry. 245 // It is cheap and safe to consult is_vfinal() at all times. 246 // Once is_vfinal is set, it must stay that way, lest we get a dangling oop. 247 set_method_flags(as_TosState(method->result_type()), 248 ((is_vfinal() ? 1 : 0) << is_vfinal_shift) | 249 ((method->is_final_method() ? 1 : 0) << is_final_shift), 250 method()->size_of_parameters()); 251 set_f1(method()); 252 byte_no = 1; 253 break; 254 default: 255 ShouldNotReachHere(); 256 break; 257 } 258 259 // Note: byte_no also appears in TemplateTable::resolve. 260 if (byte_no == 1) { 261 assert(invoke_code != Bytecodes::_invokevirtual && 262 invoke_code != Bytecodes::_invokeinterface, ""); 263 bool do_resolve = true; 264 // Don't mark invokespecial to method as resolved if sender is an interface. The receiver 265 // has to be checked that it is a subclass of the current class every time this bytecode 266 // is executed. 267 if (invoke_code == Bytecodes::_invokespecial && sender_is_interface && 268 method->name() != vmSymbols::object_initializer_name()) { 269 do_resolve = false; 270 } 271 if (invoke_code == Bytecodes::_invokestatic) { 272 assert(method->method_holder()->is_initialized() || 273 method->method_holder()->is_reentrant_initialization(Thread::current()), 274 "invalid class initialization state for invoke_static"); 275 276 if (!VM_Version::supports_fast_class_init_checks() && method->needs_clinit_barrier()) { 277 // Don't mark invokestatic to method as resolved if the holder class has not yet completed 278 // initialization. An invokestatic must only proceed if the class is initialized, but if 279 // we resolve it before then that class initialization check is skipped. 280 // 281 // When fast class initialization checks are supported (VM_Version::supports_fast_class_init_checks() == true), 282 // template interpreter supports fast class initialization check for 283 // invokestatic which doesn't require call site re-resolution to 284 // enforce class initialization barrier. 285 do_resolve = false; 286 } 287 } 288 if (do_resolve) { 289 set_bytecode_1(invoke_code); 290 } 291 } else if (byte_no == 2) { 292 if (change_to_virtual) { 293 assert(invoke_code == Bytecodes::_invokeinterface, ""); 294 // NOTE: THIS IS A HACK - BE VERY CAREFUL!!! 295 // 296 // Workaround for the case where we encounter an invokeinterface, but we 297 // should really have an _invokevirtual since the resolved method is a 298 // virtual method in java.lang.Object. This is a corner case in the spec 299 // but is presumably legal. javac does not generate this code. 300 // 301 // We do not set bytecode_1() to _invokeinterface, because that is the 302 // bytecode # used by the interpreter to see if it is resolved. In this 303 // case, the method gets reresolved with caller for each interface call 304 // because the actual selected method may not be public. 305 // 306 // We set bytecode_2() to _invokevirtual. 307 // See also interpreterRuntime.cpp. (8/25/2000) 308 invoke_code = Bytecodes::_invokevirtual; 309 } else { 310 assert(invoke_code == Bytecodes::_invokevirtual || 311 (invoke_code == Bytecodes::_invokeinterface && 312 ((method->is_private() || 313 (method->is_final() && method->method_holder() == vmClasses::Object_klass())))), 314 "unexpected invocation mode"); 315 if (invoke_code == Bytecodes::_invokeinterface && 316 (method->is_private() || method->is_final())) { 317 // We set bytecode_1() to _invokeinterface, because that is the 318 // bytecode # used by the interpreter to see if it is resolved. 319 // We set bytecode_2() to _invokevirtual. 320 set_bytecode_1(invoke_code); 321 } 322 } 323 // set up for invokevirtual, even if linking for invokeinterface also: 324 set_bytecode_2(invoke_code); 325 } else { 326 ShouldNotReachHere(); 327 } 328 NOT_PRODUCT(verify(tty)); 329 } 330 331 void ConstantPoolCacheEntry::set_direct_call(Bytecodes::Code invoke_code, const methodHandle& method, 332 bool sender_is_interface) { 333 int index = Method::nonvirtual_vtable_index; 334 // index < 0; FIXME: inline and customize set_direct_or_vtable_call 335 set_direct_or_vtable_call(invoke_code, method, index, sender_is_interface); 336 } 337 338 void ConstantPoolCacheEntry::set_vtable_call(Bytecodes::Code invoke_code, const methodHandle& method, int index) { 339 // either the method is a miranda or its holder should accept the given index 340 assert(method->method_holder()->is_interface() || method->method_holder()->verify_vtable_index(index), ""); 341 // index >= 0; FIXME: inline and customize set_direct_or_vtable_call 342 set_direct_or_vtable_call(invoke_code, method, index, false); 343 } 344 345 void ConstantPoolCacheEntry::set_itable_call(Bytecodes::Code invoke_code, 346 Klass* referenced_klass, 347 const methodHandle& method, int index) { 348 assert(method->method_holder()->verify_itable_index(index), ""); 349 assert(invoke_code == Bytecodes::_invokeinterface, ""); 350 InstanceKlass* interf = method->method_holder(); 351 assert(interf->is_interface(), "must be an interface"); 352 assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here"); 353 set_f1(referenced_klass); 354 set_f2((intx)method()); 355 set_method_flags(as_TosState(method->result_type()), 356 0, // no option bits 357 method()->size_of_parameters()); 358 set_bytecode_1(Bytecodes::_invokeinterface); 359 } 360 361 362 void ConstantPoolCacheEntry::set_method_handle(const constantPoolHandle& cpool, const CallInfo &call_info) { 363 set_method_handle_common(cpool, Bytecodes::_invokehandle, call_info); 364 } 365 366 void ConstantPoolCacheEntry::set_dynamic_call(const constantPoolHandle& cpool, const CallInfo &call_info) { 367 set_method_handle_common(cpool, Bytecodes::_invokedynamic, call_info); 368 } 369 370 void ConstantPoolCacheEntry::set_method_handle_common(const constantPoolHandle& cpool, 371 Bytecodes::Code invoke_code, 372 const CallInfo &call_info) { 373 // NOTE: This CPCE can be the subject of data races. 374 // There are three words to update: flags, refs[f2], f1 (in that order). 375 // Writers must store all other values before f1. 376 // Readers must test f1 first for non-null before reading other fields. 377 // Competing writers must acquire exclusive access via a lock. 378 // A losing writer waits on the lock until the winner writes f1 and leaves 379 // the lock, so that when the losing writer returns, he can use the linked 380 // cache entry. 381 382 JavaThread* current = JavaThread::current(); 383 objArrayHandle resolved_references(current, cpool->resolved_references()); 384 // Use the resolved_references() lock for this cpCache entry. 385 // resolved_references are created for all classes with Invokedynamic, MethodHandle 386 // or MethodType constant pool cache entries. 387 assert(resolved_references() != NULL, 388 "a resolved_references array should have been created for this class"); 389 ObjectLocker ol(resolved_references, current); 390 if (!is_f1_null()) { 391 return; 392 } 393 394 if (indy_resolution_failed()) { 395 // Before we got here, another thread got a LinkageError exception during 396 // resolution. Ignore our success and throw their exception. 397 ConstantPoolCache* cpCache = cpool->cache(); 398 int index = -1; 399 for (int i = 0; i < cpCache->length(); i++) { 400 if (cpCache->entry_at(i) == this) { 401 index = i; 402 break; 403 } 404 } 405 guarantee(index >= 0, "Didn't find cpCache entry!"); 406 int encoded_index = ResolutionErrorTable::encode_cpcache_index( 407 ConstantPool::encode_invokedynamic_index(index)); 408 JavaThread* THREAD = JavaThread::current(); // For exception macros. 409 ConstantPool::throw_resolution_error(cpool, encoded_index, THREAD); 410 return; 411 } 412 413 Method* adapter = call_info.resolved_method(); 414 const Handle appendix = call_info.resolved_appendix(); 415 const bool has_appendix = appendix.not_null(); 416 417 // Write the flags. 418 // MHs and indy are always sig-poly and have a local signature. 419 set_method_flags(as_TosState(adapter->result_type()), 420 ((has_appendix ? 1 : 0) << has_appendix_shift ) | 421 ( 1 << has_local_signature_shift ) | 422 ( 1 << is_final_shift ), 423 adapter->size_of_parameters()); 424 425 LogStream* log_stream = NULL; 426 LogStreamHandle(Debug, methodhandles, indy) lsh_indy; 427 if (lsh_indy.is_enabled()) { 428 ResourceMark rm; 429 log_stream = &lsh_indy; 430 log_stream->print_cr("set_method_handle bc=%d appendix=" PTR_FORMAT "%s method=" PTR_FORMAT " (local signature) ", 431 invoke_code, 432 p2i(appendix()), 433 (has_appendix ? "" : " (unused)"), 434 p2i(adapter)); 435 adapter->print_on(log_stream); 436 if (has_appendix) appendix()->print_on(log_stream); 437 } 438 439 // Method handle invokes and invokedynamic sites use both cp cache words. 440 // refs[f2], if not null, contains a value passed as a trailing argument to the adapter. 441 // In the general case, this could be the call site's MethodType, 442 // for use with java.lang.Invokers.checkExactType, or else a CallSite object. 443 // f1 contains the adapter method which manages the actual call. 444 // In the general case, this is a compiled LambdaForm. 445 // (The Java code is free to optimize these calls by binding other 446 // sorts of methods and appendices to call sites.) 447 // JVM-level linking is via f1, as if for invokespecial, and signatures are erased. 448 // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits. 449 // Even with the appendix, the method will never take more than 255 parameter slots. 450 // 451 // This means that given a call site like (List)mh.invoke("foo"), 452 // the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;', 453 // not '(Ljava/lang/String;)Ljava/util/List;'. 454 // The fact that String and List are involved is encoded in the MethodType in refs[f2]. 455 // This allows us to create fewer Methods, while keeping type safety. 456 // 457 458 // Store appendix, if any. 459 if (has_appendix) { 460 const int appendix_index = f2_as_index(); 461 assert(appendix_index >= 0 && appendix_index < resolved_references->length(), "oob"); 462 assert(resolved_references->obj_at(appendix_index) == NULL, "init just once"); 463 resolved_references->obj_at_put(appendix_index, appendix()); 464 } 465 466 release_set_f1(adapter); // This must be the last one to set (see NOTE above)! 467 468 // The interpreter assembly code does not check byte_2, 469 // but it is used by is_resolved, method_if_resolved, etc. 470 set_bytecode_1(invoke_code); 471 NOT_PRODUCT(verify(tty)); 472 473 if (log_stream != NULL) { 474 this->print(log_stream, 0); 475 } 476 477 assert(has_appendix == this->has_appendix(), "proper storage of appendix flag"); 478 assert(this->has_local_signature(), "proper storage of signature flag"); 479 } 480 481 bool ConstantPoolCacheEntry::save_and_throw_indy_exc( 482 const constantPoolHandle& cpool, int cpool_index, int index, constantTag tag, TRAPS) { 483 484 assert(HAS_PENDING_EXCEPTION, "No exception got thrown!"); 485 assert(PENDING_EXCEPTION->is_a(vmClasses::LinkageError_klass()), 486 "No LinkageError exception"); 487 488 // Use the resolved_references() lock for this cpCache entry. 489 // resolved_references are created for all classes with Invokedynamic, MethodHandle 490 // or MethodType constant pool cache entries. 491 JavaThread* current = THREAD; 492 objArrayHandle resolved_references(current, cpool->resolved_references()); 493 assert(resolved_references() != NULL, 494 "a resolved_references array should have been created for this class"); 495 ObjectLocker ol(resolved_references, current); 496 497 // if f1 is not null or the indy_resolution_failed flag is set then another 498 // thread either succeeded in resolving the method or got a LinkageError 499 // exception, before this thread was able to record its failure. So, clear 500 // this thread's exception and return false so caller can use the earlier 501 // thread's result. 502 if (!is_f1_null() || indy_resolution_failed()) { 503 CLEAR_PENDING_EXCEPTION; 504 return false; 505 } 506 507 Symbol* error = PENDING_EXCEPTION->klass()->name(); 508 Symbol* message = java_lang_Throwable::detail_message(PENDING_EXCEPTION); 509 510 SystemDictionary::add_resolution_error(cpool, index, error, message); 511 set_indy_resolution_failed(); 512 return true; 513 } 514 515 Method* ConstantPoolCacheEntry::method_if_resolved(const constantPoolHandle& cpool) { 516 // Decode the action of set_method and set_interface_call 517 Bytecodes::Code invoke_code = bytecode_1(); 518 if (invoke_code != (Bytecodes::Code)0) { 519 Metadata* f1 = f1_ord(); 520 if (f1 != NULL) { 521 switch (invoke_code) { 522 case Bytecodes::_invokeinterface: 523 assert(f1->is_klass(), ""); 524 return f2_as_interface_method(); 525 case Bytecodes::_invokestatic: 526 case Bytecodes::_invokespecial: 527 assert(!has_appendix(), ""); 528 case Bytecodes::_invokehandle: 529 case Bytecodes::_invokedynamic: 530 assert(f1->is_method(), ""); 531 return (Method*)f1; 532 default: 533 break; 534 } 535 } 536 } 537 invoke_code = bytecode_2(); 538 if (invoke_code != (Bytecodes::Code)0) { 539 switch (invoke_code) { 540 case Bytecodes::_invokevirtual: 541 if (is_vfinal()) { 542 // invokevirtual 543 Method* m = f2_as_vfinal_method(); 544 assert(m->is_method(), ""); 545 return m; 546 } else { 547 int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index()); 548 if (cpool->tag_at(holder_index).is_klass()) { 549 Klass* klass = cpool->resolved_klass_at(holder_index); 550 return klass->method_at_vtable(f2_as_index()); 551 } 552 } 553 break; 554 default: 555 break; 556 } 557 } 558 return NULL; 559 } 560 561 562 oop ConstantPoolCacheEntry::appendix_if_resolved(const constantPoolHandle& cpool) { 563 if (!has_appendix()) 564 return NULL; 565 const int ref_index = f2_as_index(); 566 objArrayOop resolved_references = cpool->resolved_references(); 567 return resolved_references->obj_at(ref_index); 568 } 569 570 571 #if INCLUDE_JVMTI 572 573 void log_adjust(const char* entry_type, Method* old_method, Method* new_method, bool* trace_name_printed) { 574 ResourceMark rm; 575 576 if (!(*trace_name_printed)) { 577 log_info(redefine, class, update)("adjust: name=%s", old_method->method_holder()->external_name()); 578 *trace_name_printed = true; 579 } 580 log_trace(redefine, class, update, constantpool) 581 ("cpc %s entry update: %s", entry_type, new_method->external_name()); 582 } 583 584 // RedefineClasses() API support: 585 // If this ConstantPoolCacheEntry refers to old_method then update it 586 // to refer to new_method. 587 void ConstantPoolCacheEntry::adjust_method_entry(Method* old_method, 588 Method* new_method, bool * trace_name_printed) { 589 590 if (is_vfinal()) { 591 // virtual and final so _f2 contains method ptr instead of vtable index 592 if (f2_as_vfinal_method() == old_method) { 593 // match old_method so need an update 594 // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values 595 _f2 = (intptr_t)new_method; 596 log_adjust("vfinal", old_method, new_method, trace_name_printed); 597 } 598 return; 599 } 600 601 assert (_f1 != NULL, "should not call with uninteresting entry"); 602 603 if (!(_f1->is_method())) { 604 // _f1 is a Klass* for an interface, _f2 is the method 605 if (f2_as_interface_method() == old_method) { 606 _f2 = (intptr_t)new_method; 607 log_adjust("interface", old_method, new_method, trace_name_printed); 608 } 609 } else if (_f1 == old_method) { 610 _f1 = new_method; 611 log_adjust("special, static or dynamic", old_method, new_method, trace_name_printed); 612 } 613 } 614 615 // a constant pool cache entry should never contain old or obsolete methods 616 bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() { 617 Method* m = get_interesting_method_entry(); 618 // return false if m refers to a non-deleted old or obsolete method 619 if (m != NULL) { 620 assert(m->is_valid() && m->is_method(), "m is a valid method"); 621 return !m->is_old() && !m->is_obsolete(); // old is always set for old and obsolete 622 } else { 623 return true; 624 } 625 } 626 627 Method* ConstantPoolCacheEntry::get_interesting_method_entry() { 628 if (!is_method_entry()) { 629 // not a method entry so not interesting by default 630 return NULL; 631 } 632 Method* m = NULL; 633 if (is_vfinal()) { 634 // virtual and final so _f2 contains method ptr instead of vtable index 635 m = f2_as_vfinal_method(); 636 } else if (is_f1_null()) { 637 // NULL _f1 means this is a virtual entry so also not interesting 638 return NULL; 639 } else { 640 if (!(_f1->is_method())) { 641 // _f1 is a Klass* for an interface 642 m = f2_as_interface_method(); 643 } else { 644 m = f1_as_method(); 645 } 646 } 647 assert(m != NULL && m->is_method(), "sanity check"); 648 if (m == NULL || !m->is_method()) { 649 return NULL; 650 } 651 return m; 652 } 653 #endif // INCLUDE_JVMTI 654 655 void ConstantPoolCacheEntry::print(outputStream* st, int index) const { 656 // print separator 657 if (index == 0) st->print_cr(" -------------"); 658 // print entry 659 st->print("%3d (" PTR_FORMAT ") ", index, (intptr_t)this); 660 st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(), 661 constant_pool_index()); 662 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_f1); 663 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_f2); 664 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_flags); 665 st->print_cr(" -------------"); 666 } 667 668 void ConstantPoolCacheEntry::verify(outputStream* st) const { 669 // not implemented yet 670 } 671 672 // Implementation of ConstantPoolCache 673 674 ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data, 675 const intStack& index_map, 676 const intStack& invokedynamic_index_map, 677 const intStack& invokedynamic_map, TRAPS) { 678 679 const int length = index_map.length() + invokedynamic_index_map.length(); 680 int size = ConstantPoolCache::size(length); 681 682 return new (loader_data, size, MetaspaceObj::ConstantPoolCacheType, THREAD) 683 ConstantPoolCache(length, index_map, invokedynamic_index_map, invokedynamic_map); 684 } 685 686 void ConstantPoolCache::initialize(const intArray& inverse_index_map, 687 const intArray& invokedynamic_inverse_index_map, 688 const intArray& invokedynamic_references_map) { 689 for (int i = 0; i < inverse_index_map.length(); i++) { 690 ConstantPoolCacheEntry* e = entry_at(i); 691 int original_index = inverse_index_map.at(i); 692 e->initialize_entry(original_index); 693 assert(entry_at(i) == e, "sanity"); 694 } 695 696 // Append invokedynamic entries at the end 697 int invokedynamic_offset = inverse_index_map.length(); 698 for (int i = 0; i < invokedynamic_inverse_index_map.length(); i++) { 699 int offset = i + invokedynamic_offset; 700 ConstantPoolCacheEntry* e = entry_at(offset); 701 int original_index = invokedynamic_inverse_index_map.at(i); 702 e->initialize_entry(original_index); 703 assert(entry_at(offset) == e, "sanity"); 704 } 705 706 for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) { 707 const int cpci = invokedynamic_references_map.at(ref); 708 if (cpci >= 0) { 709 entry_at(cpci)->initialize_resolved_reference_index(ref); 710 } 711 } 712 } 713 714 void ConstantPoolCache::verify_just_initialized() { 715 DEBUG_ONLY(walk_entries_for_initialization(/*check_only = */ true)); 716 } 717 718 void ConstantPoolCache::remove_unshareable_info() { 719 walk_entries_for_initialization(/*check_only = */ false); 720 } 721 722 void ConstantPoolCache::walk_entries_for_initialization(bool check_only) { 723 Arguments::assert_is_dumping_archive(); 724 // When dumping the archive, we want to clean up the ConstantPoolCache 725 // to remove any effect of linking due to the execution of Java code -- 726 // each ConstantPoolCacheEntry will have the same contents as if 727 // ConstantPoolCache::initialize has just returned: 728 // 729 // - We keep the ConstantPoolCache::constant_pool_index() bits for all entries. 730 // - We keep the "f2" field for entries used by invokedynamic and invokehandle 731 // - All other bits in the entries are cleared to zero. 732 ResourceMark rm; 733 734 InstanceKlass* ik = constant_pool()->pool_holder(); 735 bool* f2_used = NEW_RESOURCE_ARRAY(bool, length()); 736 memset(f2_used, 0, sizeof(bool) * length()); 737 738 Thread* current = Thread::current(); 739 740 // Find all the slots that we need to preserve f2 741 for (int i = 0; i < ik->methods()->length(); i++) { 742 Method* m = ik->methods()->at(i); 743 RawBytecodeStream bcs(methodHandle(current, m)); 744 while (!bcs.is_last_bytecode()) { 745 Bytecodes::Code opcode = bcs.raw_next(); 746 switch (opcode) { 747 case Bytecodes::_invokedynamic: { 748 int index = Bytes::get_native_u4(bcs.bcp() + 1); 749 int cp_cache_index = constant_pool()->invokedynamic_cp_cache_index(index); 750 f2_used[cp_cache_index] = 1; 751 } 752 break; 753 case Bytecodes::_invokehandle: { 754 int cp_cache_index = Bytes::get_native_u2(bcs.bcp() + 1); 755 f2_used[cp_cache_index] = 1; 756 } 757 break; 758 default: 759 break; 760 } 761 } 762 } 763 764 if (check_only) { 765 DEBUG_ONLY( 766 for (int i=0; i<length(); i++) { 767 entry_at(i)->verify_just_initialized(f2_used[i]); 768 }) 769 } else { 770 for (int i=0; i<length(); i++) { 771 entry_at(i)->reinitialize(f2_used[i]); 772 } 773 } 774 } 775 776 void ConstantPoolCache::deallocate_contents(ClassLoaderData* data) { 777 assert(!is_shared(), "shared caches are not deallocated"); 778 data->remove_handle(_resolved_references); 779 set_resolved_references(OopHandle()); 780 MetadataFactory::free_array<u2>(data, _reference_map); 781 set_reference_map(NULL); 782 } 783 784 #if INCLUDE_CDS_JAVA_HEAP 785 oop ConstantPoolCache::archived_references() { 786 if (_archived_references_index < 0) { 787 return NULL; 788 } 789 return HeapShared::get_root(_archived_references_index); 790 } 791 792 void ConstantPoolCache::clear_archived_references() { 793 if (_archived_references_index >= 0) { 794 HeapShared::clear_root(_archived_references_index); 795 _archived_references_index = -1; 796 } 797 } 798 799 void ConstantPoolCache::set_archived_references(oop o) { 800 assert(DumpSharedSpaces, "called only during runtime"); 801 _archived_references_index = HeapShared::append_root(o); 802 } 803 #endif 804 805 #if INCLUDE_JVMTI 806 // RedefineClasses() API support: 807 // If any entry of this ConstantPoolCache points to any of 808 // old_methods, replace it with the corresponding new_method. 809 void ConstantPoolCache::adjust_method_entries(bool * trace_name_printed) { 810 for (int i = 0; i < length(); i++) { 811 ConstantPoolCacheEntry* entry = entry_at(i); 812 Method* old_method = entry->get_interesting_method_entry(); 813 if (old_method == NULL || !old_method->is_old()) { 814 continue; // skip uninteresting entries 815 } 816 if (old_method->is_deleted()) { 817 // clean up entries with deleted methods 818 entry->initialize_entry(entry->constant_pool_index()); 819 continue; 820 } 821 Method* new_method = old_method->get_new_method(); 822 entry_at(i)->adjust_method_entry(old_method, new_method, trace_name_printed); 823 } 824 } 825 826 // the constant pool cache should never contain old or obsolete methods 827 bool ConstantPoolCache::check_no_old_or_obsolete_entries() { 828 ResourceMark rm; 829 for (int i = 1; i < length(); i++) { 830 Method* m = entry_at(i)->get_interesting_method_entry(); 831 if (m != NULL && !entry_at(i)->check_no_old_or_obsolete_entries()) { 832 log_trace(redefine, class, update, constantpool) 833 ("cpcache check found old method entry: class: %s, old: %d, obsolete: %d, method: %s", 834 constant_pool()->pool_holder()->external_name(), m->is_old(), m->is_obsolete(), m->external_name()); 835 return false; 836 } 837 } 838 return true; 839 } 840 841 void ConstantPoolCache::dump_cache() { 842 for (int i = 1; i < length(); i++) { 843 if (entry_at(i)->get_interesting_method_entry() != NULL) { 844 entry_at(i)->print(tty, i); 845 } 846 } 847 } 848 #endif // INCLUDE_JVMTI 849 850 void ConstantPoolCache::metaspace_pointers_do(MetaspaceClosure* it) { 851 log_trace(cds)("Iter(ConstantPoolCache): %p", this); 852 it->push(&_constant_pool); 853 it->push(&_reference_map); 854 } 855 856 // Printing 857 858 void ConstantPoolCache::print_on(outputStream* st) const { 859 st->print_cr("%s", internal_name()); 860 // print constant pool cache entries 861 for (int i = 0; i < length(); i++) entry_at(i)->print(st, i); 862 } 863 864 void ConstantPoolCache::print_value_on(outputStream* st) const { 865 st->print("cache [%d]", length()); 866 print_address_on(st); 867 st->print(" for "); 868 constant_pool()->print_value_on(st); 869 } 870 871 872 // Verification 873 874 void ConstantPoolCache::verify_on(outputStream* st) { 875 // print constant pool cache entries 876 for (int i = 0; i < length(); i++) entry_at(i)->verify(st); 877 }