1 /* 2 * Copyright (c) 1998, 2018, 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 "classfile/resolutionErrors.hpp" 27 #include "interpreter/bytecodeStream.hpp" 28 #include "interpreter/bytecodes.hpp" 29 #include "interpreter/interpreter.hpp" 30 #include "interpreter/rewriter.hpp" 31 #include "logging/log.hpp" 32 #include "memory/metadataFactory.hpp" 33 #include "memory/metaspaceClosure.hpp" 34 #include "memory/resourceArea.hpp" 35 #include "memory/universe.inline.hpp" 36 #include "oops/access.inline.hpp" 37 #include "oops/constantPool.inline.hpp" 38 #include "oops/cpCache.inline.hpp" 39 #include "oops/objArrayOop.inline.hpp" 40 #include "oops/oop.inline.hpp" 41 #include "prims/methodHandles.hpp" 42 #include "runtime/atomic.hpp" 43 #include "runtime/handles.inline.hpp" 44 #include "runtime/orderAccess.inline.hpp" 45 #include "utilities/macros.hpp" 46 47 // Implementation of ConstantPoolCacheEntry 48 49 void ConstantPoolCacheEntry::initialize_entry(int index) { 50 assert(0 < index && index < 0x10000, "sanity check"); 51 _indices = index; 52 _f1 = NULL; 53 _f2 = _flags = 0; 54 assert(constant_pool_index() == index, ""); 55 } 56 57 void ConstantPoolCacheEntry::verify_just_initialized(bool f2_used) { 58 assert((_indices & (~cp_index_mask)) == 0, "sanity"); 59 assert(_f1 == NULL, "sanity"); 60 assert(_flags == 0, "sanity"); 61 if (!f2_used) { 62 assert(_f2 == 0, "sanity"); 63 } 64 } 65 66 void ConstantPoolCacheEntry::reinitialize(bool f2_used) { 67 _indices &= cp_index_mask; 68 _f1 = NULL; 69 _flags = 0; 70 if (!f2_used) { 71 _f2 = 0; 72 } 73 } 74 75 int ConstantPoolCacheEntry::make_flags(TosState state, 76 int option_bits, 77 int field_index_or_method_params) { 78 assert(state < number_of_states, "Invalid state in make_flags"); 79 int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params; 80 // Preserve existing flag bit values 81 // The low bits are a field offset, or else the method parameter size. 82 #ifdef ASSERT 83 TosState old_state = flag_state(); 84 assert(old_state == (TosState)0 || old_state == state, 85 "inconsistent cpCache flags state"); 86 #endif 87 return (_flags | f) ; 88 } 89 90 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) { 91 #ifdef ASSERT 92 // Read once. 93 volatile Bytecodes::Code c = bytecode_1(); 94 assert(c == 0 || c == code || code == 0, "update must be consistent"); 95 #endif 96 // Need to flush pending stores here before bytecode is written. 97 OrderAccess::release_store(&_indices, _indices | ((u_char)code << bytecode_1_shift)); 98 } 99 100 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) { 101 #ifdef ASSERT 102 // Read once. 103 volatile Bytecodes::Code c = bytecode_2(); 104 assert(c == 0 || c == code || code == 0, "update must be consistent"); 105 #endif 106 // Need to flush pending stores here before bytecode is written. 107 OrderAccess::release_store(&_indices, _indices | ((u_char)code << bytecode_2_shift)); 108 } 109 110 // Sets f1, ordering with previous writes. 111 void ConstantPoolCacheEntry::release_set_f1(Metadata* f1) { 112 assert(f1 != NULL, ""); 113 OrderAccess::release_store(&_f1, f1); 114 } 115 116 void ConstantPoolCacheEntry::set_indy_resolution_failed() { 117 OrderAccess::release_store(&_flags, _flags | (1 << indy_resolution_failed_shift)); 118 } 119 120 // Note that concurrent update of both bytecodes can leave one of them 121 // reset to zero. This is harmless; the interpreter will simply re-resolve 122 // the damaged entry. More seriously, the memory synchronization is needed 123 // to flush other fields (f1, f2) completely to memory before the bytecodes 124 // are updated, lest other processors see a non-zero bytecode but zero f1/f2. 125 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code, 126 Bytecodes::Code put_code, 127 Klass* field_holder, 128 int field_index, 129 int field_offset, 130 TosState field_type, 131 bool is_final, 132 bool is_volatile, 133 Klass* root_klass) { 134 set_f1(field_holder); 135 set_f2(field_offset); 136 assert((field_index & field_index_mask) == field_index, 137 "field index does not fit in low flag bits"); 138 set_field_flags(field_type, 139 ((is_volatile ? 1 : 0) << is_volatile_shift) | 140 ((is_final ? 1 : 0) << is_final_shift), 141 field_index); 142 set_bytecode_1(get_code); 143 set_bytecode_2(put_code); 144 NOT_PRODUCT(verify(tty)); 145 } 146 147 void ConstantPoolCacheEntry::set_parameter_size(int value) { 148 // This routine is called only in corner cases where the CPCE is not yet initialized. 149 // See AbstractInterpreter::deopt_continue_after_entry. 150 assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value, 151 "size must not change: parameter_size=%d, value=%d", parameter_size(), value); 152 // Setting the parameter size by itself is only safe if the 153 // current value of _flags is 0, otherwise another thread may have 154 // updated it and we don't want to overwrite that value. Don't 155 // bother trying to update it once it's nonzero but always make 156 // sure that the final parameter size agrees with what was passed. 157 if (_flags == 0) { 158 intx newflags = (value & parameter_size_mask); 159 Atomic::cmpxchg(newflags, &_flags, (intx)0); 160 } 161 guarantee(parameter_size() == value, 162 "size must not change: parameter_size=%d, value=%d", parameter_size(), value); 163 } 164 165 void ConstantPoolCacheEntry::set_direct_or_vtable_call(Bytecodes::Code invoke_code, 166 const methodHandle& method, 167 int vtable_index, 168 bool sender_is_interface) { 169 bool is_vtable_call = (vtable_index >= 0); // FIXME: split this method on this boolean 170 assert(method->interpreter_entry() != NULL, "should have been set at this point"); 171 assert(!method->is_obsolete(), "attempt to write obsolete method to cpCache"); 172 173 int byte_no = -1; 174 bool change_to_virtual = false; 175 176 switch (invoke_code) { 177 case Bytecodes::_invokeinterface: 178 // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface 179 // instruction somehow links to a non-interface method (in Object). 180 // In that case, the method has no itable index and must be invoked as a virtual. 181 // Set a flag to keep track of this corner case. 182 assert(method->is_public(), "Calling non-public method in Object with invokeinterface"); 183 change_to_virtual = true; 184 185 // ...and fall through as if we were handling invokevirtual: 186 case Bytecodes::_invokevirtual: 187 { 188 if (!is_vtable_call) { 189 assert(method->can_be_statically_bound(), ""); 190 // set_f2_as_vfinal_method checks if is_vfinal flag is true. 191 set_method_flags(as_TosState(method->result_type()), 192 ( 1 << is_vfinal_shift) | 193 ((method->is_final_method() ? 1 : 0) << is_final_shift) | 194 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift), 195 method()->size_of_parameters()); 196 set_f2_as_vfinal_method(method()); 197 } else { 198 assert(!method->can_be_statically_bound(), ""); 199 assert(vtable_index >= 0, "valid index"); 200 assert(!method->is_final_method(), "sanity"); 201 set_method_flags(as_TosState(method->result_type()), 202 ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift), 203 method()->size_of_parameters()); 204 set_f2(vtable_index); 205 } 206 byte_no = 2; 207 break; 208 } 209 210 case Bytecodes::_invokespecial: 211 case Bytecodes::_invokestatic: 212 assert(!is_vtable_call, ""); 213 // Note: Read and preserve the value of the is_vfinal flag on any 214 // invokevirtual bytecode shared with this constant pool cache entry. 215 // It is cheap and safe to consult is_vfinal() at all times. 216 // Once is_vfinal is set, it must stay that way, lest we get a dangling oop. 217 set_method_flags(as_TosState(method->result_type()), 218 ((is_vfinal() ? 1 : 0) << is_vfinal_shift) | 219 ((method->is_final_method() ? 1 : 0) << is_final_shift), 220 method()->size_of_parameters()); 221 set_f1(method()); 222 byte_no = 1; 223 break; 224 default: 225 ShouldNotReachHere(); 226 break; 227 } 228 229 // Note: byte_no also appears in TemplateTable::resolve. 230 if (byte_no == 1) { 231 assert(invoke_code != Bytecodes::_invokevirtual && 232 invoke_code != Bytecodes::_invokeinterface, ""); 233 // Don't mark invokespecial to method as resolved if sender is an interface. The receiver 234 // has to be checked that it is a subclass of the current class every time this bytecode 235 // is executed. 236 if (invoke_code != Bytecodes::_invokespecial || !sender_is_interface || 237 method->name() == vmSymbols::object_initializer_name()) { 238 set_bytecode_1(invoke_code); 239 } 240 } else if (byte_no == 2) { 241 if (change_to_virtual) { 242 assert(invoke_code == Bytecodes::_invokeinterface, ""); 243 // NOTE: THIS IS A HACK - BE VERY CAREFUL!!! 244 // 245 // Workaround for the case where we encounter an invokeinterface, but we 246 // should really have an _invokevirtual since the resolved method is a 247 // virtual method in java.lang.Object. This is a corner case in the spec 248 // but is presumably legal. javac does not generate this code. 249 // 250 // We set bytecode_1() to _invokeinterface, because that is the 251 // bytecode # used by the interpreter to see if it is resolved. 252 // We set bytecode_2() to _invokevirtual. 253 // See also interpreterRuntime.cpp. (8/25/2000) 254 // Only set resolved for the invokeinterface case if method is public. 255 // Otherwise, the method needs to be reresolved with caller for each 256 // interface call. 257 if (method->is_public()) set_bytecode_1(invoke_code); 258 } else { 259 assert(invoke_code == Bytecodes::_invokevirtual, ""); 260 } 261 // set up for invokevirtual, even if linking for invokeinterface also: 262 set_bytecode_2(Bytecodes::_invokevirtual); 263 } else { 264 ShouldNotReachHere(); 265 } 266 NOT_PRODUCT(verify(tty)); 267 } 268 269 void ConstantPoolCacheEntry::set_direct_call(Bytecodes::Code invoke_code, const methodHandle& method, 270 bool sender_is_interface) { 271 int index = Method::nonvirtual_vtable_index; 272 // index < 0; FIXME: inline and customize set_direct_or_vtable_call 273 set_direct_or_vtable_call(invoke_code, method, index, sender_is_interface); 274 } 275 276 void ConstantPoolCacheEntry::set_vtable_call(Bytecodes::Code invoke_code, const methodHandle& method, int index) { 277 // either the method is a miranda or its holder should accept the given index 278 assert(method->method_holder()->is_interface() || method->method_holder()->verify_vtable_index(index), ""); 279 // index >= 0; FIXME: inline and customize set_direct_or_vtable_call 280 set_direct_or_vtable_call(invoke_code, method, index, false); 281 } 282 283 void ConstantPoolCacheEntry::set_itable_call(Bytecodes::Code invoke_code, 284 Klass* referenced_klass, 285 const methodHandle& method, int index) { 286 assert(method->method_holder()->verify_itable_index(index), ""); 287 assert(invoke_code == Bytecodes::_invokeinterface, ""); 288 InstanceKlass* interf = method->method_holder(); 289 assert(interf->is_interface(), "must be an interface"); 290 assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here"); 291 set_f1(referenced_klass); 292 set_f2((intx)method()); 293 set_method_flags(as_TosState(method->result_type()), 294 0, // no option bits 295 method()->size_of_parameters()); 296 set_bytecode_1(Bytecodes::_invokeinterface); 297 } 298 299 300 void ConstantPoolCacheEntry::set_method_handle(const constantPoolHandle& cpool, const CallInfo &call_info) { 301 set_method_handle_common(cpool, Bytecodes::_invokehandle, call_info); 302 } 303 304 void ConstantPoolCacheEntry::set_dynamic_call(const constantPoolHandle& cpool, const CallInfo &call_info) { 305 set_method_handle_common(cpool, Bytecodes::_invokedynamic, call_info); 306 } 307 308 void ConstantPoolCacheEntry::set_method_handle_common(const constantPoolHandle& cpool, 309 Bytecodes::Code invoke_code, 310 const CallInfo &call_info) { 311 // NOTE: This CPCE can be the subject of data races. 312 // There are three words to update: flags, refs[f2], f1 (in that order). 313 // Writers must store all other values before f1. 314 // Readers must test f1 first for non-null before reading other fields. 315 // Competing writers must acquire exclusive access via a lock. 316 // A losing writer waits on the lock until the winner writes f1 and leaves 317 // the lock, so that when the losing writer returns, he can use the linked 318 // cache entry. 319 320 objArrayHandle resolved_references(Thread::current(), cpool->resolved_references()); 321 // Use the resolved_references() lock for this cpCache entry. 322 // resolved_references are created for all classes with Invokedynamic, MethodHandle 323 // or MethodType constant pool cache entries. 324 assert(resolved_references() != NULL, 325 "a resolved_references array should have been created for this class"); 326 ObjectLocker ol(resolved_references, Thread::current()); 327 if (!is_f1_null()) { 328 return; 329 } 330 331 if (indy_resolution_failed()) { 332 // Before we got here, another thread got a LinkageError exception during 333 // resolution. Ignore our success and throw their exception. 334 ConstantPoolCache* cpCache = cpool->cache(); 335 int index = -1; 336 for (int i = 0; i < cpCache->length(); i++) { 337 if (cpCache->entry_at(i) == this) { 338 index = i; 339 break; 340 } 341 } 342 guarantee(index >= 0, "Didn't find cpCache entry!"); 343 int encoded_index = ResolutionErrorTable::encode_cpcache_index( 344 ConstantPool::encode_invokedynamic_index(index)); 345 Thread* THREAD = Thread::current(); 346 ConstantPool::throw_resolution_error(cpool, encoded_index, THREAD); 347 return; 348 } 349 350 const methodHandle adapter = call_info.resolved_method(); 351 const Handle appendix = call_info.resolved_appendix(); 352 const Handle method_type = call_info.resolved_method_type(); 353 const bool has_appendix = appendix.not_null(); 354 const bool has_method_type = method_type.not_null(); 355 356 // Write the flags. 357 set_method_flags(as_TosState(adapter->result_type()), 358 ((has_appendix ? 1 : 0) << has_appendix_shift ) | 359 ((has_method_type ? 1 : 0) << has_method_type_shift) | 360 ( 1 << is_final_shift ), 361 adapter->size_of_parameters()); 362 363 if (TraceInvokeDynamic) { 364 ttyLocker ttyl; 365 tty->print_cr("set_method_handle bc=%d appendix=" PTR_FORMAT "%s method_type=" PTR_FORMAT "%s method=" PTR_FORMAT " ", 366 invoke_code, 367 p2i(appendix()), (has_appendix ? "" : " (unused)"), 368 p2i(method_type()), (has_method_type ? "" : " (unused)"), 369 p2i(adapter())); 370 adapter->print(); 371 if (has_appendix) appendix()->print(); 372 } 373 374 // Method handle invokes and invokedynamic sites use both cp cache words. 375 // refs[f2], if not null, contains a value passed as a trailing argument to the adapter. 376 // In the general case, this could be the call site's MethodType, 377 // for use with java.lang.Invokers.checkExactType, or else a CallSite object. 378 // f1 contains the adapter method which manages the actual call. 379 // In the general case, this is a compiled LambdaForm. 380 // (The Java code is free to optimize these calls by binding other 381 // sorts of methods and appendices to call sites.) 382 // JVM-level linking is via f1, as if for invokespecial, and signatures are erased. 383 // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits. 384 // Even with the appendix, the method will never take more than 255 parameter slots. 385 // 386 // This means that given a call site like (List)mh.invoke("foo"), 387 // the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;', 388 // not '(Ljava/lang/String;)Ljava/util/List;'. 389 // The fact that String and List are involved is encoded in the MethodType in refs[f2]. 390 // This allows us to create fewer Methods, while keeping type safety. 391 // 392 393 // Store appendix, if any. 394 if (has_appendix) { 395 const int appendix_index = f2_as_index() + _indy_resolved_references_appendix_offset; 396 assert(appendix_index >= 0 && appendix_index < resolved_references->length(), "oob"); 397 assert(resolved_references->obj_at(appendix_index) == NULL, "init just once"); 398 resolved_references->obj_at_put(appendix_index, appendix()); 399 } 400 401 // Store MethodType, if any. 402 if (has_method_type) { 403 const int method_type_index = f2_as_index() + _indy_resolved_references_method_type_offset; 404 assert(method_type_index >= 0 && method_type_index < resolved_references->length(), "oob"); 405 assert(resolved_references->obj_at(method_type_index) == NULL, "init just once"); 406 resolved_references->obj_at_put(method_type_index, method_type()); 407 } 408 409 release_set_f1(adapter()); // This must be the last one to set (see NOTE above)! 410 411 // The interpreter assembly code does not check byte_2, 412 // but it is used by is_resolved, method_if_resolved, etc. 413 set_bytecode_1(invoke_code); 414 NOT_PRODUCT(verify(tty)); 415 if (TraceInvokeDynamic) { 416 ttyLocker ttyl; 417 this->print(tty, 0); 418 } 419 } 420 421 bool ConstantPoolCacheEntry::save_and_throw_indy_exc( 422 const constantPoolHandle& cpool, int cpool_index, int index, constantTag tag, TRAPS) { 423 424 assert(HAS_PENDING_EXCEPTION, "No exception got thrown!"); 425 assert(PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass()), 426 "No LinkageError exception"); 427 428 // Use the resolved_references() lock for this cpCache entry. 429 // resolved_references are created for all classes with Invokedynamic, MethodHandle 430 // or MethodType constant pool cache entries. 431 objArrayHandle resolved_references(Thread::current(), cpool->resolved_references()); 432 assert(resolved_references() != NULL, 433 "a resolved_references array should have been created for this class"); 434 ObjectLocker ol(resolved_references, THREAD); 435 436 // if f1 is not null or the indy_resolution_failed flag is set then another 437 // thread either succeeded in resolving the method or got a LinkageError 438 // exception, before this thread was able to record its failure. So, clear 439 // this thread's exception and return false so caller can use the earlier 440 // thread's result. 441 if (!is_f1_null() || indy_resolution_failed()) { 442 CLEAR_PENDING_EXCEPTION; 443 return false; 444 } 445 446 Symbol* error = PENDING_EXCEPTION->klass()->name(); 447 Symbol* message = java_lang_Throwable::detail_message(PENDING_EXCEPTION); 448 assert(message != NULL, "Missing detail message"); 449 450 SystemDictionary::add_resolution_error(cpool, index, error, message); 451 set_indy_resolution_failed(); 452 return true; 453 } 454 455 Method* ConstantPoolCacheEntry::method_if_resolved(const constantPoolHandle& cpool) { 456 // Decode the action of set_method and set_interface_call 457 Bytecodes::Code invoke_code = bytecode_1(); 458 if (invoke_code != (Bytecodes::Code)0) { 459 Metadata* f1 = f1_ord(); 460 if (f1 != NULL) { 461 switch (invoke_code) { 462 case Bytecodes::_invokeinterface: 463 assert(f1->is_klass(), ""); 464 return klassItable::method_for_itable_index((Klass*)f1, f2_as_index()); 465 case Bytecodes::_invokestatic: 466 case Bytecodes::_invokespecial: 467 assert(!has_appendix(), ""); 468 case Bytecodes::_invokehandle: 469 case Bytecodes::_invokedynamic: 470 assert(f1->is_method(), ""); 471 return (Method*)f1; 472 default: 473 break; 474 } 475 } 476 } 477 invoke_code = bytecode_2(); 478 if (invoke_code != (Bytecodes::Code)0) { 479 switch (invoke_code) { 480 case Bytecodes::_invokevirtual: 481 if (is_vfinal()) { 482 // invokevirtual 483 Method* m = f2_as_vfinal_method(); 484 assert(m->is_method(), ""); 485 return m; 486 } else { 487 int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index()); 488 if (cpool->tag_at(holder_index).is_klass()) { 489 Klass* klass = cpool->resolved_klass_at(holder_index); 490 return klass->method_at_vtable(f2_as_index()); 491 } 492 } 493 break; 494 default: 495 break; 496 } 497 } 498 return NULL; 499 } 500 501 502 oop ConstantPoolCacheEntry::appendix_if_resolved(const constantPoolHandle& cpool) { 503 if (!has_appendix()) 504 return NULL; 505 const int ref_index = f2_as_index() + _indy_resolved_references_appendix_offset; 506 objArrayOop resolved_references = cpool->resolved_references(); 507 return resolved_references->obj_at(ref_index); 508 } 509 510 511 oop ConstantPoolCacheEntry::method_type_if_resolved(const constantPoolHandle& cpool) { 512 if (!has_method_type()) 513 return NULL; 514 const int ref_index = f2_as_index() + _indy_resolved_references_method_type_offset; 515 objArrayOop resolved_references = cpool->resolved_references(); 516 return resolved_references->obj_at(ref_index); 517 } 518 519 520 #if INCLUDE_JVMTI 521 522 void log_adjust(const char* entry_type, Method* old_method, Method* new_method, bool* trace_name_printed) { 523 if (log_is_enabled(Info, redefine, class, update)) { 524 ResourceMark rm; 525 if (!(*trace_name_printed)) { 526 log_info(redefine, class, update)("adjust: name=%s", old_method->method_holder()->external_name()); 527 *trace_name_printed = true; 528 } 529 log_debug(redefine, class, update, constantpool) 530 ("cpc %s entry update: %s(%s)", entry_type, new_method->name()->as_C_string(), new_method->signature()->as_C_string()); 531 } 532 } 533 534 // RedefineClasses() API support: 535 // If this ConstantPoolCacheEntry refers to old_method then update it 536 // to refer to new_method. 537 void ConstantPoolCacheEntry::adjust_method_entry(Method* old_method, 538 Method* new_method, bool * trace_name_printed) { 539 540 if (is_vfinal()) { 541 // virtual and final so _f2 contains method ptr instead of vtable index 542 if (f2_as_vfinal_method() == old_method) { 543 // match old_method so need an update 544 // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values 545 _f2 = (intptr_t)new_method; 546 log_adjust("vfinal", old_method, new_method, trace_name_printed); 547 } 548 return; 549 } 550 551 assert (_f1 != NULL, "should not call with uninteresting entry"); 552 553 if (!(_f1->is_method())) { 554 // _f1 is a Klass* for an interface, _f2 is the method 555 if (f2_as_interface_method() == old_method) { 556 _f2 = (intptr_t)new_method; 557 log_adjust("interface", old_method, new_method, trace_name_printed); 558 } 559 } else if (_f1 == old_method) { 560 _f1 = new_method; 561 log_adjust("special, static or dynamic", old_method, new_method, trace_name_printed); 562 } 563 } 564 565 // a constant pool cache entry should never contain old or obsolete methods 566 bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() { 567 Method* m = get_interesting_method_entry(NULL); 568 // return false if m refers to a non-deleted old or obsolete method 569 if (m != NULL) { 570 assert(m->is_valid() && m->is_method(), "m is a valid method"); 571 return !m->is_old() && !m->is_obsolete(); // old is always set for old and obsolete 572 } else { 573 return true; 574 } 575 } 576 577 Method* ConstantPoolCacheEntry::get_interesting_method_entry(Klass* k) { 578 if (!is_method_entry()) { 579 // not a method entry so not interesting by default 580 return NULL; 581 } 582 Method* m = NULL; 583 if (is_vfinal()) { 584 // virtual and final so _f2 contains method ptr instead of vtable index 585 m = f2_as_vfinal_method(); 586 } else if (is_f1_null()) { 587 // NULL _f1 means this is a virtual entry so also not interesting 588 return NULL; 589 } else { 590 if (!(_f1->is_method())) { 591 // _f1 is a Klass* for an interface 592 m = f2_as_interface_method(); 593 } else { 594 m = f1_as_method(); 595 } 596 } 597 assert(m != NULL && m->is_method(), "sanity check"); 598 if (m == NULL || !m->is_method() || (k != NULL && m->method_holder() != k)) { 599 // robustness for above sanity checks or method is not in 600 // the interesting class 601 return NULL; 602 } 603 // the method is in the interesting class so the entry is interesting 604 return m; 605 } 606 #endif // INCLUDE_JVMTI 607 608 void ConstantPoolCacheEntry::print(outputStream* st, int index) const { 609 // print separator 610 if (index == 0) st->print_cr(" -------------"); 611 // print entry 612 st->print("%3d (" PTR_FORMAT ") ", index, (intptr_t)this); 613 st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(), 614 constant_pool_index()); 615 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_f1); 616 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_f2); 617 st->print_cr(" [ " PTR_FORMAT "]", (intptr_t)_flags); 618 st->print_cr(" -------------"); 619 } 620 621 void ConstantPoolCacheEntry::verify(outputStream* st) const { 622 // not implemented yet 623 } 624 625 // Implementation of ConstantPoolCache 626 627 ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data, 628 const intStack& index_map, 629 const intStack& invokedynamic_index_map, 630 const intStack& invokedynamic_map, TRAPS) { 631 632 const int length = index_map.length() + invokedynamic_index_map.length(); 633 int size = ConstantPoolCache::size(length); 634 635 return new (loader_data, size, MetaspaceObj::ConstantPoolCacheType, THREAD) 636 ConstantPoolCache(length, index_map, invokedynamic_index_map, invokedynamic_map); 637 } 638 639 void ConstantPoolCache::initialize(const intArray& inverse_index_map, 640 const intArray& invokedynamic_inverse_index_map, 641 const intArray& invokedynamic_references_map) { 642 for (int i = 0; i < inverse_index_map.length(); i++) { 643 ConstantPoolCacheEntry* e = entry_at(i); 644 int original_index = inverse_index_map.at(i); 645 e->initialize_entry(original_index); 646 assert(entry_at(i) == e, "sanity"); 647 } 648 649 // Append invokedynamic entries at the end 650 int invokedynamic_offset = inverse_index_map.length(); 651 for (int i = 0; i < invokedynamic_inverse_index_map.length(); i++) { 652 int offset = i + invokedynamic_offset; 653 ConstantPoolCacheEntry* e = entry_at(offset); 654 int original_index = invokedynamic_inverse_index_map.at(i); 655 e->initialize_entry(original_index); 656 assert(entry_at(offset) == e, "sanity"); 657 } 658 659 for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) { 660 const int cpci = invokedynamic_references_map.at(ref); 661 if (cpci >= 0) { 662 #ifdef ASSERT 663 // invokedynamic and invokehandle have more entries; check if they 664 // all point to the same constant pool cache entry. 665 for (int entry = 1; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) { 666 const int cpci_next = invokedynamic_references_map.at(ref + entry); 667 assert(cpci == cpci_next, "%d == %d", cpci, cpci_next); 668 } 669 #endif 670 entry_at(cpci)->initialize_resolved_reference_index(ref); 671 ref += ConstantPoolCacheEntry::_indy_resolved_references_entries - 1; // skip extra entries 672 } 673 } 674 } 675 676 void ConstantPoolCache::verify_just_initialized() { 677 DEBUG_ONLY(walk_entries_for_initialization(/*check_only = */ true)); 678 } 679 680 void ConstantPoolCache::remove_unshareable_info() { 681 walk_entries_for_initialization(/*check_only = */ false); 682 } 683 684 void ConstantPoolCache::walk_entries_for_initialization(bool check_only) { 685 assert(DumpSharedSpaces, "sanity"); 686 // When dumping the archive, we want to clean up the ConstantPoolCache 687 // to remove any effect of linking due to the execution of Java code -- 688 // each ConstantPoolCacheEntry will have the same contents as if 689 // ConstantPoolCache::initialize has just returned: 690 // 691 // - We keep the ConstantPoolCache::constant_pool_index() bits for all entries. 692 // - We keep the "f2" field for entries used by invokedynamic and invokehandle 693 // - All other bits in the entries are cleared to zero. 694 ResourceMark rm; 695 696 InstanceKlass* ik = constant_pool()->pool_holder(); 697 bool* f2_used = NEW_RESOURCE_ARRAY(bool, length()); 698 memset(f2_used, 0, sizeof(bool) * length()); 699 700 // Find all the slots that we need to preserve f2 701 for (int i = 0; i < ik->methods()->length(); i++) { 702 Method* m = ik->methods()->at(i); 703 RawBytecodeStream bcs(m); 704 while (!bcs.is_last_bytecode()) { 705 Bytecodes::Code opcode = bcs.raw_next(); 706 switch (opcode) { 707 case Bytecodes::_invokedynamic: { 708 int index = Bytes::get_native_u4(bcs.bcp() + 1); 709 int cp_cache_index = constant_pool()->invokedynamic_cp_cache_index(index); 710 f2_used[cp_cache_index] = 1; 711 } 712 break; 713 case Bytecodes::_invokehandle: { 714 int cp_cache_index = Bytes::get_native_u2(bcs.bcp() + 1); 715 f2_used[cp_cache_index] = 1; 716 } 717 break; 718 default: 719 break; 720 } 721 } 722 } 723 724 if (check_only) { 725 DEBUG_ONLY( 726 for (int i=0; i<length(); i++) { 727 entry_at(i)->verify_just_initialized(f2_used[i]); 728 }) 729 } else { 730 for (int i=0; i<length(); i++) { 731 entry_at(i)->reinitialize(f2_used[i]); 732 } 733 } 734 } 735 736 void ConstantPoolCache::deallocate_contents(ClassLoaderData* data) { 737 assert(!is_shared(), "shared caches are not deallocated"); 738 data->remove_handle(_resolved_references); 739 set_resolved_references(NULL); 740 MetadataFactory::free_array<u2>(data, _reference_map); 741 set_reference_map(NULL); 742 } 743 744 #if INCLUDE_CDS_JAVA_HEAP 745 oop ConstantPoolCache::archived_references() { 746 // Loading an archive root forces the oop to become strongly reachable. 747 // For example, if it is loaded during concurrent marking in a SATB 748 // collector, it will be enqueued to the SATB queue, effectively 749 // shading the previously white object gray. 750 return RootAccess<IN_ARCHIVE_ROOT>::oop_load(&_archived_references); 751 } 752 753 void ConstantPoolCache::set_archived_references(oop o) { 754 assert(DumpSharedSpaces, "called only during runtime"); 755 RootAccess<IN_ARCHIVE_ROOT>::oop_store(&_archived_references, o); 756 } 757 #endif 758 759 #if INCLUDE_JVMTI 760 // RedefineClasses() API support: 761 // If any entry of this ConstantPoolCache points to any of 762 // old_methods, replace it with the corresponding new_method. 763 void ConstantPoolCache::adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed) { 764 for (int i = 0; i < length(); i++) { 765 ConstantPoolCacheEntry* entry = entry_at(i); 766 Method* old_method = entry->get_interesting_method_entry(holder); 767 if (old_method == NULL || !old_method->is_old()) { 768 continue; // skip uninteresting entries 769 } 770 if (old_method->is_deleted()) { 771 // clean up entries with deleted methods 772 entry->initialize_entry(entry->constant_pool_index()); 773 continue; 774 } 775 Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum()); 776 777 assert(new_method != NULL, "method_with_idnum() should not be NULL"); 778 assert(old_method != new_method, "sanity check"); 779 780 entry_at(i)->adjust_method_entry(old_method, new_method, trace_name_printed); 781 } 782 } 783 784 // the constant pool cache should never contain old or obsolete methods 785 bool ConstantPoolCache::check_no_old_or_obsolete_entries() { 786 for (int i = 1; i < length(); i++) { 787 if (entry_at(i)->get_interesting_method_entry(NULL) != NULL && 788 !entry_at(i)->check_no_old_or_obsolete_entries()) { 789 return false; 790 } 791 } 792 return true; 793 } 794 795 void ConstantPoolCache::dump_cache() { 796 for (int i = 1; i < length(); i++) { 797 if (entry_at(i)->get_interesting_method_entry(NULL) != NULL) { 798 entry_at(i)->print(tty, i); 799 } 800 } 801 } 802 #endif // INCLUDE_JVMTI 803 804 void ConstantPoolCache::metaspace_pointers_do(MetaspaceClosure* it) { 805 log_trace(cds)("Iter(ConstantPoolCache): %p", this); 806 it->push(&_constant_pool); 807 it->push(&_reference_map); 808 } 809 810 // Printing 811 812 void ConstantPoolCache::print_on(outputStream* st) const { 813 assert(is_constantPoolCache(), "obj must be constant pool cache"); 814 st->print_cr("%s", internal_name()); 815 // print constant pool cache entries 816 for (int i = 0; i < length(); i++) entry_at(i)->print(st, i); 817 } 818 819 void ConstantPoolCache::print_value_on(outputStream* st) const { 820 assert(is_constantPoolCache(), "obj must be constant pool cache"); 821 st->print("cache [%d]", length()); 822 print_address_on(st); 823 st->print(" for "); 824 constant_pool()->print_value_on(st); 825 } 826 827 828 // Verification 829 830 void ConstantPoolCache::verify_on(outputStream* st) { 831 guarantee(is_constantPoolCache(), "obj must be constant pool cache"); 832 // print constant pool cache entries 833 for (int i = 0; i < length(); i++) entry_at(i)->verify(st); 834 }