1 /* 2 * Copyright (c) 1997, 2024, 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/cdsConfig.hpp" 27 #include "cds/cppVtables.hpp" 28 #include "cds/metaspaceShared.hpp" 29 #include "classfile/classLoader.hpp" 30 #include "classfile/classLoaderDataGraph.hpp" 31 #include "classfile/metadataOnStackMark.hpp" 32 #include "classfile/symbolTable.hpp" 33 #include "classfile/systemDictionary.hpp" 34 #include "classfile/vmClasses.hpp" 35 #include "code/codeCache.hpp" 36 #include "code/debugInfoRec.hpp" 37 #include "compiler/compilationPolicy.hpp" 38 #include "gc/shared/collectedHeap.inline.hpp" 39 #include "interpreter/bytecodeStream.hpp" 40 #include "interpreter/bytecodeTracer.hpp" 41 #include "interpreter/bytecodes.hpp" 42 #include "interpreter/interpreter.hpp" 43 #include "interpreter/oopMapCache.hpp" 44 #include "logging/log.hpp" 45 #include "logging/logStream.hpp" 46 #include "logging/logTag.hpp" 47 #include "memory/allocation.inline.hpp" 48 #include "memory/metadataFactory.hpp" 49 #include "memory/metaspaceClosure.hpp" 50 #include "memory/oopFactory.hpp" 51 #include "memory/resourceArea.hpp" 52 #include "memory/universe.hpp" 53 #include "nmt/memTracker.hpp" 54 #include "oops/constMethod.hpp" 55 #include "oops/constantPool.hpp" 56 #include "oops/klass.inline.hpp" 57 #include "oops/method.inline.hpp" 58 #include "oops/methodData.hpp" 59 #include "oops/objArrayKlass.hpp" 60 #include "oops/objArrayOop.inline.hpp" 61 #include "oops/oop.inline.hpp" 62 #include "oops/symbol.hpp" 63 #include "prims/jvmtiExport.hpp" 64 #include "prims/methodHandles.hpp" 65 #include "runtime/atomic.hpp" 66 #include "runtime/arguments.hpp" 67 #include "runtime/continuationEntry.hpp" 68 #include "runtime/frame.inline.hpp" 69 #include "runtime/handles.inline.hpp" 70 #include "runtime/init.hpp" 71 #include "runtime/java.hpp" 72 #include "runtime/orderAccess.hpp" 73 #include "runtime/perfData.hpp" 74 #include "runtime/relocator.hpp" 75 #include "runtime/safepointVerifiers.hpp" 76 #include "runtime/sharedRuntime.hpp" 77 #include "runtime/signature.hpp" 78 #include "runtime/threads.hpp" 79 #include "runtime/vm_version.hpp" 80 #include "utilities/align.hpp" 81 #include "utilities/quickSort.hpp" 82 #include "utilities/vmError.hpp" 83 #include "utilities/xmlstream.hpp" 84 85 // Implementation of Method 86 87 Method* Method::allocate(ClassLoaderData* loader_data, 88 int byte_code_size, 89 AccessFlags access_flags, 90 InlineTableSizes* sizes, 91 ConstMethod::MethodType method_type, 92 Symbol* name, 93 TRAPS) { 94 assert(!access_flags.is_native() || byte_code_size == 0, 95 "native methods should not contain byte codes"); 96 ConstMethod* cm = ConstMethod::allocate(loader_data, 97 byte_code_size, 98 sizes, 99 method_type, 100 CHECK_NULL); 101 int size = Method::size(access_flags.is_native()); 102 return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags, name); 103 } 104 105 Method::Method(ConstMethod* xconst, AccessFlags access_flags, Symbol* name) { 106 NoSafepointVerifier no_safepoint; 107 set_constMethod(xconst); 108 set_access_flags(access_flags); 109 set_intrinsic_id(vmIntrinsics::_none); 110 clear_method_data(); 111 clear_method_counters(); 112 set_vtable_index(Method::garbage_vtable_index); 113 114 // Fix and bury in Method* 115 set_interpreter_entry(nullptr); // sets i2i entry and from_int 116 set_adapter_entry(nullptr); 117 Method::clear_code(); // from_c/from_i get set to c2i/i2i 118 119 if (access_flags.is_native()) { 120 clear_native_function(); 121 set_signature_handler(nullptr); 122 } 123 124 NOT_PRODUCT(set_compiled_invocation_count(0);) 125 // Name is very useful for debugging. 126 NOT_PRODUCT(_name = name;) 127 } 128 129 // Release Method*. The nmethod will be gone when we get here because 130 // we've walked the code cache. 131 void Method::deallocate_contents(ClassLoaderData* loader_data) { 132 MetadataFactory::free_metadata(loader_data, constMethod()); 133 set_constMethod(nullptr); 134 MetadataFactory::free_metadata(loader_data, method_data()); 135 clear_method_data(); 136 MetadataFactory::free_metadata(loader_data, method_counters()); 137 clear_method_counters(); 138 // The nmethod will be gone when we get here. 139 if (code() != nullptr) _code = nullptr; 140 } 141 142 void Method::release_C_heap_structures() { 143 if (method_data()) { 144 method_data()->release_C_heap_structures(); 145 146 // Destroy MethodData embedded lock 147 method_data()->~MethodData(); 148 } 149 } 150 151 address Method::get_i2c_entry() { 152 assert(adapter() != nullptr, "must have"); 153 return adapter()->get_i2c_entry(); 154 } 155 156 address Method::get_c2i_entry() { 157 assert(adapter() != nullptr, "must have"); 158 return adapter()->get_c2i_entry(); 159 } 160 161 address Method::get_c2i_unverified_entry() { 162 assert(adapter() != nullptr, "must have"); 163 return adapter()->get_c2i_unverified_entry(); 164 } 165 166 address Method::get_c2i_no_clinit_check_entry() { 167 assert(VM_Version::supports_fast_class_init_checks(), ""); 168 assert(adapter() != nullptr, "must have"); 169 return adapter()->get_c2i_no_clinit_check_entry(); 170 } 171 172 char* Method::name_and_sig_as_C_string() const { 173 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature()); 174 } 175 176 char* Method::name_and_sig_as_C_string(char* buf, int size) const { 177 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size); 178 } 179 180 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) { 181 const char* klass_name = klass->external_name(); 182 int klass_name_len = (int)strlen(klass_name); 183 int method_name_len = method_name->utf8_length(); 184 int len = klass_name_len + 1 + method_name_len + signature->utf8_length(); 185 char* dest = NEW_RESOURCE_ARRAY(char, len + 1); 186 strcpy(dest, klass_name); 187 dest[klass_name_len] = '.'; 188 strcpy(&dest[klass_name_len + 1], method_name->as_C_string()); 189 strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string()); 190 dest[len] = 0; 191 return dest; 192 } 193 194 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) { 195 Symbol* klass_name = klass->name(); 196 klass_name->as_klass_external_name(buf, size); 197 int len = (int)strlen(buf); 198 199 if (len < size - 1) { 200 buf[len++] = '.'; 201 202 method_name->as_C_string(&(buf[len]), size - len); 203 len = (int)strlen(buf); 204 205 signature->as_C_string(&(buf[len]), size - len); 206 } 207 208 return buf; 209 } 210 211 const char* Method::external_name() const { 212 return external_name(constants()->pool_holder(), name(), signature()); 213 } 214 215 void Method::print_external_name(outputStream *os) const { 216 print_external_name(os, constants()->pool_holder(), name(), signature()); 217 } 218 219 const char* Method::external_name(Klass* klass, Symbol* method_name, Symbol* signature) { 220 stringStream ss; 221 print_external_name(&ss, klass, method_name, signature); 222 return ss.as_string(); 223 } 224 225 void Method::print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature) { 226 signature->print_as_signature_external_return_type(os); 227 os->print(" %s.%s(", klass->external_name(), method_name->as_C_string()); 228 signature->print_as_signature_external_parameters(os); 229 os->print(")"); 230 } 231 232 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) { 233 if (log_is_enabled(Debug, exceptions)) { 234 ResourceMark rm(THREAD); 235 log_debug(exceptions)("Looking for catch handler for exception of type \"%s\" in method \"%s\"", 236 ex_klass == nullptr ? "null" : ex_klass->external_name(), mh->name()->as_C_string()); 237 } 238 // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index) 239 // access exception table 240 ExceptionTable table(mh()); 241 int length = table.length(); 242 // iterate through all entries sequentially 243 constantPoolHandle pool(THREAD, mh->constants()); 244 for (int i = 0; i < length; i ++) { 245 //reacquire the table in case a GC happened 246 ExceptionTable table(mh()); 247 int beg_bci = table.start_pc(i); 248 int end_bci = table.end_pc(i); 249 assert(beg_bci <= end_bci, "inconsistent exception table"); 250 log_debug(exceptions)(" - checking exception table entry for BCI %d to %d", 251 beg_bci, end_bci); 252 253 if (beg_bci <= throw_bci && throw_bci < end_bci) { 254 // exception handler bci range covers throw_bci => investigate further 255 log_debug(exceptions)(" - entry covers throw point BCI %d", throw_bci); 256 257 int handler_bci = table.handler_pc(i); 258 int klass_index = table.catch_type_index(i); 259 if (klass_index == 0) { 260 if (log_is_enabled(Info, exceptions)) { 261 ResourceMark rm(THREAD); 262 log_info(exceptions)("Found catch-all handler for exception of type \"%s\" in method \"%s\" at BCI: %d", 263 ex_klass == nullptr ? "null" : ex_klass->external_name(), mh->name()->as_C_string(), handler_bci); 264 } 265 return handler_bci; 266 } else if (ex_klass == nullptr) { 267 // Is this even possible? 268 if (log_is_enabled(Info, exceptions)) { 269 ResourceMark rm(THREAD); 270 log_info(exceptions)("null exception class is implicitly caught by handler in method \"%s\" at BCI: %d", 271 mh()->name()->as_C_string(), handler_bci); 272 } 273 return handler_bci; 274 } else { 275 if (log_is_enabled(Debug, exceptions)) { 276 ResourceMark rm(THREAD); 277 log_debug(exceptions)(" - resolving catch type \"%s\"", 278 pool->klass_name_at(klass_index)->as_C_string()); 279 } 280 // we know the exception class => get the constraint class 281 // this may require loading of the constraint class; if verification 282 // fails or some other exception occurs, return handler_bci 283 Klass* k = pool->klass_at(klass_index, THREAD); 284 if (HAS_PENDING_EXCEPTION) { 285 if (log_is_enabled(Debug, exceptions)) { 286 ResourceMark rm(THREAD); 287 log_debug(exceptions)(" - exception \"%s\" occurred resolving catch type", 288 PENDING_EXCEPTION->klass()->external_name()); 289 } 290 return handler_bci; 291 } 292 assert(k != nullptr, "klass not loaded"); 293 if (ex_klass->is_subtype_of(k)) { 294 if (log_is_enabled(Info, exceptions)) { 295 ResourceMark rm(THREAD); 296 log_info(exceptions)("Found matching handler for exception of type \"%s\" in method \"%s\" at BCI: %d", 297 ex_klass == nullptr ? "null" : ex_klass->external_name(), mh->name()->as_C_string(), handler_bci); 298 } 299 return handler_bci; 300 } 301 } 302 } 303 } 304 305 if (log_is_enabled(Debug, exceptions)) { 306 ResourceMark rm(THREAD); 307 log_debug(exceptions)("No catch handler found for exception of type \"%s\" in method \"%s\"", 308 ex_klass->external_name(), mh->name()->as_C_string()); 309 } 310 311 return -1; 312 } 313 314 void Method::mask_for(int bci, InterpreterOopMap* mask) { 315 methodHandle h_this(Thread::current(), this); 316 mask_for(h_this, bci, mask); 317 } 318 319 void Method::mask_for(const methodHandle& this_mh, int bci, InterpreterOopMap* mask) { 320 assert(this_mh() == this, "Sanity"); 321 method_holder()->mask_for(this_mh, bci, mask); 322 } 323 324 int Method::bci_from(address bcp) const { 325 if (is_native() && bcp == nullptr) { 326 return 0; 327 } 328 // Do not have a ResourceMark here because AsyncGetCallTrace stack walking code 329 // may call this after interrupting a nested ResourceMark. 330 assert((is_native() && bcp == code_base()) || contains(bcp) || VMError::is_error_reported(), 331 "bcp doesn't belong to this method. bcp: " PTR_FORMAT, p2i(bcp)); 332 333 return int(bcp - code_base()); 334 } 335 336 337 int Method::validate_bci(int bci) const { 338 return (bci == 0 || bci < code_size()) ? bci : -1; 339 } 340 341 // Return bci if it appears to be a valid bcp 342 // Return -1 otherwise. 343 // Used by profiling code, when invalid data is a possibility. 344 // The caller is responsible for validating the Method* itself. 345 int Method::validate_bci_from_bcp(address bcp) const { 346 // keep bci as -1 if not a valid bci 347 int bci = -1; 348 if (bcp == nullptr || bcp == code_base()) { 349 // code_size() may return 0 and we allow 0 here 350 // the method may be native 351 bci = 0; 352 } else if (contains(bcp)) { 353 bci = int(bcp - code_base()); 354 } 355 // Assert that if we have dodged any asserts, bci is negative. 356 assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0"); 357 return bci; 358 } 359 360 address Method::bcp_from(int bci) const { 361 assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()), 362 "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native"); 363 address bcp = code_base() + bci; 364 assert((is_native() && bcp == code_base()) || contains(bcp), "bcp doesn't belong to this method"); 365 return bcp; 366 } 367 368 address Method::bcp_from(address bcp) const { 369 if (is_native() && bcp == nullptr) { 370 return code_base(); 371 } else { 372 return bcp; 373 } 374 } 375 376 int Method::size(bool is_native) { 377 // If native, then include pointers for native_function and signature_handler 378 int extra_bytes = (is_native) ? 2*sizeof(address*) : 0; 379 int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord; 380 return align_metadata_size(header_size() + extra_words); 381 } 382 383 Symbol* Method::klass_name() const { 384 return method_holder()->name(); 385 } 386 387 void Method::metaspace_pointers_do(MetaspaceClosure* it) { 388 log_trace(cds)("Iter(Method): %p", this); 389 390 if (!method_holder()->is_rewritten()) { 391 it->push(&_constMethod, MetaspaceClosure::_writable); 392 } else { 393 it->push(&_constMethod); 394 } 395 it->push(&_method_data); 396 it->push(&_method_counters); 397 NOT_PRODUCT(it->push(&_name);) 398 } 399 400 #if INCLUDE_CDS 401 // Attempt to return method to original state. Clear any pointers 402 // (to objects outside the shared spaces). We won't be able to predict 403 // where they should point in a new JVM. Further initialize some 404 // entries now in order allow them to be write protected later. 405 406 void Method::remove_unshareable_info() { 407 unlink_method(); 408 JFR_ONLY(REMOVE_METHOD_ID(this);) 409 } 410 411 void Method::restore_unshareable_info(TRAPS) { 412 assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored"); 413 assert(!queued_for_compilation(), "method's queued_for_compilation flag should not be set"); 414 } 415 #endif 416 417 void Method::set_vtable_index(int index) { 418 if (is_shared() && !MetaspaceShared::remapped_readwrite() && method_holder()->verified_at_dump_time()) { 419 // At runtime initialize_vtable is rerun as part of link_class_impl() 420 // for a shared class loaded by the non-boot loader to obtain the loader 421 // constraints based on the runtime classloaders' context. 422 return; // don't write into the shared class 423 } else { 424 _vtable_index = index; 425 } 426 } 427 428 void Method::set_itable_index(int index) { 429 if (is_shared() && !MetaspaceShared::remapped_readwrite() && method_holder()->verified_at_dump_time()) { 430 // At runtime initialize_itable is rerun as part of link_class_impl() 431 // for a shared class loaded by the non-boot loader to obtain the loader 432 // constraints based on the runtime classloaders' context. The dumptime 433 // itable index should be the same as the runtime index. 434 assert(_vtable_index == itable_index_max - index, 435 "archived itable index is different from runtime index"); 436 return; // don’t write into the shared class 437 } else { 438 _vtable_index = itable_index_max - index; 439 } 440 assert(valid_itable_index(), ""); 441 } 442 443 // The RegisterNatives call being attempted tried to register with a method that 444 // is not native. Ask JVM TI what prefixes have been specified. Then check 445 // to see if the native method is now wrapped with the prefixes. See the 446 // SetNativeMethodPrefix(es) functions in the JVM TI Spec for details. 447 static Method* find_prefixed_native(Klass* k, Symbol* name, Symbol* signature, TRAPS) { 448 #if INCLUDE_JVMTI 449 ResourceMark rm(THREAD); 450 Method* method; 451 int name_len = name->utf8_length(); 452 char* name_str = name->as_utf8(); 453 int prefix_count; 454 char** prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count); 455 for (int i = 0; i < prefix_count; i++) { 456 char* prefix = prefixes[i]; 457 int prefix_len = (int)strlen(prefix); 458 459 // try adding this prefix to the method name and see if it matches another method name 460 int trial_len = name_len + prefix_len; 461 char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1); 462 strcpy(trial_name_str, prefix); 463 strcat(trial_name_str, name_str); 464 TempNewSymbol trial_name = SymbolTable::probe(trial_name_str, trial_len); 465 if (trial_name == nullptr) { 466 continue; // no such symbol, so this prefix wasn't used, try the next prefix 467 } 468 method = k->lookup_method(trial_name, signature); 469 if (method == nullptr) { 470 continue; // signature doesn't match, try the next prefix 471 } 472 if (method->is_native()) { 473 method->set_is_prefixed_native(); 474 return method; // wahoo, we found a prefixed version of the method, return it 475 } 476 // found as non-native, so prefix is good, add it, probably just need more prefixes 477 name_len = trial_len; 478 name_str = trial_name_str; 479 } 480 #endif // INCLUDE_JVMTI 481 return nullptr; // not found 482 } 483 484 bool Method::register_native(Klass* k, Symbol* name, Symbol* signature, address entry, TRAPS) { 485 Method* method = k->lookup_method(name, signature); 486 if (method == nullptr) { 487 ResourceMark rm(THREAD); 488 stringStream st; 489 st.print("Method '"); 490 print_external_name(&st, k, name, signature); 491 st.print("' name or signature does not match"); 492 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false); 493 } 494 if (!method->is_native()) { 495 // trying to register to a non-native method, see if a JVM TI agent has added prefix(es) 496 method = find_prefixed_native(k, name, signature, THREAD); 497 if (method == nullptr) { 498 ResourceMark rm(THREAD); 499 stringStream st; 500 st.print("Method '"); 501 print_external_name(&st, k, name, signature); 502 st.print("' is not declared as native"); 503 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodError(), st.as_string(), false); 504 } 505 } 506 507 if (entry != nullptr) { 508 method->set_native_function(entry, native_bind_event_is_interesting); 509 } else { 510 method->clear_native_function(); 511 } 512 if (log_is_enabled(Debug, jni, resolve)) { 513 ResourceMark rm(THREAD); 514 log_debug(jni, resolve)("[Registering JNI native method %s.%s]", 515 method->method_holder()->external_name(), 516 method->name()->as_C_string()); 517 } 518 return true; 519 } 520 521 bool Method::was_executed_more_than(int n) { 522 // Invocation counter is reset when the Method* is compiled. 523 // If the method has compiled code we therefore assume it has 524 // be executed more than n times. 525 if (is_accessor() || is_empty_method() || (code() != nullptr)) { 526 // interpreter doesn't bump invocation counter of trivial methods 527 // compiler does not bump invocation counter of compiled methods 528 return true; 529 } 530 else if ((method_counters() != nullptr && 531 method_counters()->invocation_counter()->carry()) || 532 (method_data() != nullptr && 533 method_data()->invocation_counter()->carry())) { 534 // The carry bit is set when the counter overflows and causes 535 // a compilation to occur. We don't know how many times 536 // the counter has been reset, so we simply assume it has 537 // been executed more than n times. 538 return true; 539 } else { 540 return invocation_count() > n; 541 } 542 } 543 544 void Method::print_invocation_count(outputStream* st) { 545 //---< compose+print method return type, klass, name, and signature >--- 546 if (is_static()) { st->print("static "); } 547 if (is_final()) { st->print("final "); } 548 if (is_synchronized()) { st->print("synchronized "); } 549 if (is_native()) { st->print("native "); } 550 st->print("%s::", method_holder()->external_name()); 551 name()->print_symbol_on(st); 552 signature()->print_symbol_on(st); 553 554 if (WizardMode) { 555 // dump the size of the byte codes 556 st->print(" {%d}", code_size()); 557 } 558 st->cr(); 559 560 // Counting based on signed int counters tends to overflow with 561 // longer-running workloads on fast machines. The counters under 562 // consideration here, however, are limited in range by counting 563 // logic. See InvocationCounter:count_limit for example. 564 // No "overflow precautions" need to be implemented here. 565 st->print_cr (" interpreter_invocation_count: " INT32_FORMAT_W(11), interpreter_invocation_count()); 566 st->print_cr (" invocation_counter: " INT32_FORMAT_W(11), invocation_count()); 567 st->print_cr (" backedge_counter: " INT32_FORMAT_W(11), backedge_count()); 568 569 if (method_data() != nullptr) { 570 st->print_cr (" decompile_count: " UINT32_FORMAT_W(11), method_data()->decompile_count()); 571 } 572 573 #ifndef PRODUCT 574 if (CountCompiledCalls) { 575 st->print_cr (" compiled_invocation_count: " INT64_FORMAT_W(11), compiled_invocation_count()); 576 } 577 #endif 578 } 579 580 // Build a MethodData* object to hold profiling information collected on this 581 // method when requested. 582 void Method::build_profiling_method_data(const methodHandle& method, TRAPS) { 583 // Do not profile the method if metaspace has hit an OOM previously 584 // allocating profiling data. Callers clear pending exception so don't 585 // add one here. 586 if (ClassLoaderDataGraph::has_metaspace_oom()) { 587 return; 588 } 589 590 ClassLoaderData* loader_data = method->method_holder()->class_loader_data(); 591 MethodData* method_data = MethodData::allocate(loader_data, method, THREAD); 592 if (HAS_PENDING_EXCEPTION) { 593 CompileBroker::log_metaspace_failure(); 594 ClassLoaderDataGraph::set_metaspace_oom(true); 595 return; // return the exception (which is cleared) 596 } 597 598 if (!Atomic::replace_if_null(&method->_method_data, method_data)) { 599 MetadataFactory::free_metadata(loader_data, method_data); 600 return; 601 } 602 603 if (PrintMethodData && (Verbose || WizardMode)) { 604 ResourceMark rm(THREAD); 605 tty->print("build_profiling_method_data for "); 606 method->print_name(tty); 607 tty->cr(); 608 // At the end of the run, the MDO, full of data, will be dumped. 609 } 610 } 611 612 MethodCounters* Method::build_method_counters(Thread* current, Method* m) { 613 // Do not profile the method if metaspace has hit an OOM previously 614 if (ClassLoaderDataGraph::has_metaspace_oom()) { 615 return nullptr; 616 } 617 618 methodHandle mh(current, m); 619 MethodCounters* counters; 620 if (current->is_Java_thread()) { 621 JavaThread* THREAD = JavaThread::cast(current); // For exception macros. 622 // Use the TRAPS version for a JavaThread so it will adjust the GC threshold 623 // if needed. 624 counters = MethodCounters::allocate_with_exception(mh, THREAD); 625 if (HAS_PENDING_EXCEPTION) { 626 CLEAR_PENDING_EXCEPTION; 627 } 628 } else { 629 // Call metaspace allocation that doesn't throw exception if the 630 // current thread isn't a JavaThread, ie. the VMThread. 631 counters = MethodCounters::allocate_no_exception(mh); 632 } 633 634 if (counters == nullptr) { 635 CompileBroker::log_metaspace_failure(); 636 ClassLoaderDataGraph::set_metaspace_oom(true); 637 return nullptr; 638 } 639 640 if (!mh->init_method_counters(counters)) { 641 MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters); 642 } 643 644 return mh->method_counters(); 645 } 646 647 bool Method::init_method_counters(MethodCounters* counters) { 648 // Try to install a pointer to MethodCounters, return true on success. 649 return Atomic::replace_if_null(&_method_counters, counters); 650 } 651 652 void Method::set_exception_handler_entered(int handler_bci) { 653 if (ProfileExceptionHandlers) { 654 MethodData* mdo = method_data(); 655 if (mdo != nullptr) { 656 BitData handler_data = mdo->exception_handler_bci_to_data(handler_bci); 657 handler_data.set_exception_handler_entered(); 658 } 659 } 660 } 661 662 int Method::extra_stack_words() { 663 // not an inline function, to avoid a header dependency on Interpreter 664 return extra_stack_entries() * Interpreter::stackElementSize; 665 } 666 667 bool Method::compute_has_loops_flag() { 668 BytecodeStream bcs(methodHandle(Thread::current(), this)); 669 Bytecodes::Code bc; 670 671 while ((bc = bcs.next()) >= 0) { 672 switch (bc) { 673 case Bytecodes::_ifeq: 674 case Bytecodes::_ifnull: 675 case Bytecodes::_iflt: 676 case Bytecodes::_ifle: 677 case Bytecodes::_ifne: 678 case Bytecodes::_ifnonnull: 679 case Bytecodes::_ifgt: 680 case Bytecodes::_ifge: 681 case Bytecodes::_if_icmpeq: 682 case Bytecodes::_if_icmpne: 683 case Bytecodes::_if_icmplt: 684 case Bytecodes::_if_icmpgt: 685 case Bytecodes::_if_icmple: 686 case Bytecodes::_if_icmpge: 687 case Bytecodes::_if_acmpeq: 688 case Bytecodes::_if_acmpne: 689 case Bytecodes::_goto: 690 case Bytecodes::_jsr: 691 if (bcs.dest() < bcs.next_bci()) { 692 return set_has_loops(); 693 } 694 break; 695 696 case Bytecodes::_goto_w: 697 case Bytecodes::_jsr_w: 698 if (bcs.dest_w() < bcs.next_bci()) { 699 return set_has_loops(); 700 } 701 break; 702 703 case Bytecodes::_lookupswitch: { 704 Bytecode_lookupswitch lookupswitch(this, bcs.bcp()); 705 if (lookupswitch.default_offset() < 0) { 706 return set_has_loops(); 707 } else { 708 for (int i = 0; i < lookupswitch.number_of_pairs(); ++i) { 709 LookupswitchPair pair = lookupswitch.pair_at(i); 710 if (pair.offset() < 0) { 711 return set_has_loops(); 712 } 713 } 714 } 715 break; 716 } 717 case Bytecodes::_tableswitch: { 718 Bytecode_tableswitch tableswitch(this, bcs.bcp()); 719 if (tableswitch.default_offset() < 0) { 720 return set_has_loops(); 721 } else { 722 for (int i = 0; i < tableswitch.length(); ++i) { 723 if (tableswitch.dest_offset_at(i) < 0) { 724 return set_has_loops(); 725 } 726 } 727 } 728 break; 729 } 730 default: 731 break; 732 } 733 } 734 735 _flags.set_has_loops_flag_init(true); 736 return false; 737 } 738 739 bool Method::is_final_method(AccessFlags class_access_flags) const { 740 // or "does_not_require_vtable_entry" 741 // default method or overpass can occur, is not final (reuses vtable entry) 742 // private methods in classes get vtable entries for backward class compatibility. 743 if (is_overpass() || is_default_method()) return false; 744 return is_final() || class_access_flags.is_final(); 745 } 746 747 bool Method::is_final_method() const { 748 return is_final_method(method_holder()->access_flags()); 749 } 750 751 bool Method::is_default_method() const { 752 if (method_holder() != nullptr && 753 method_holder()->is_interface() && 754 !is_abstract() && !is_private()) { 755 return true; 756 } else { 757 return false; 758 } 759 } 760 761 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const { 762 if (is_final_method(class_access_flags)) return true; 763 #ifdef ASSERT 764 bool is_nonv = (vtable_index() == nonvirtual_vtable_index); 765 if (class_access_flags.is_interface()) { 766 ResourceMark rm; 767 assert(is_nonv == is_static() || is_nonv == is_private(), 768 "nonvirtual unexpected for non-static, non-private: %s", 769 name_and_sig_as_C_string()); 770 } 771 #endif 772 assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question"); 773 return vtable_index() == nonvirtual_vtable_index; 774 } 775 776 bool Method::can_be_statically_bound() const { 777 return can_be_statically_bound(method_holder()->access_flags()); 778 } 779 780 bool Method::can_be_statically_bound(InstanceKlass* context) const { 781 return (method_holder() == context) && can_be_statically_bound(); 782 } 783 784 /** 785 * Returns false if this is one of specially treated methods for 786 * which we have to provide stack trace in throw in compiled code. 787 * Returns true otherwise. 788 */ 789 bool Method::can_omit_stack_trace() { 790 if (klass_name() == vmSymbols::sun_invoke_util_ValueConversions()) { 791 return false; // All methods in sun.invoke.util.ValueConversions 792 } 793 return true; 794 } 795 796 bool Method::is_accessor() const { 797 return is_getter() || is_setter(); 798 } 799 800 bool Method::is_getter() const { 801 if (code_size() != 5) return false; 802 if (size_of_parameters() != 1) return false; 803 if (java_code_at(0) != Bytecodes::_aload_0) return false; 804 if (java_code_at(1) != Bytecodes::_getfield) return false; 805 switch (java_code_at(4)) { 806 case Bytecodes::_ireturn: 807 case Bytecodes::_lreturn: 808 case Bytecodes::_freturn: 809 case Bytecodes::_dreturn: 810 case Bytecodes::_areturn: 811 break; 812 default: 813 return false; 814 } 815 return true; 816 } 817 818 bool Method::is_setter() const { 819 if (code_size() != 6) return false; 820 if (java_code_at(0) != Bytecodes::_aload_0) return false; 821 switch (java_code_at(1)) { 822 case Bytecodes::_iload_1: 823 case Bytecodes::_aload_1: 824 case Bytecodes::_fload_1: 825 if (size_of_parameters() != 2) return false; 826 break; 827 case Bytecodes::_dload_1: 828 case Bytecodes::_lload_1: 829 if (size_of_parameters() != 3) return false; 830 break; 831 default: 832 return false; 833 } 834 if (java_code_at(2) != Bytecodes::_putfield) return false; 835 if (java_code_at(5) != Bytecodes::_return) return false; 836 return true; 837 } 838 839 bool Method::is_constant_getter() const { 840 int last_index = code_size() - 1; 841 // Check if the first 1-3 bytecodes are a constant push 842 // and the last bytecode is a return. 843 return (2 <= code_size() && code_size() <= 4 && 844 Bytecodes::is_const(java_code_at(0)) && 845 Bytecodes::length_for(java_code_at(0)) == last_index && 846 Bytecodes::is_return(java_code_at(last_index))); 847 } 848 849 bool Method::is_initializer() const { 850 return is_object_initializer() || is_static_initializer(); 851 } 852 853 bool Method::has_valid_initializer_flags() const { 854 return (is_static() || 855 method_holder()->major_version() < 51); 856 } 857 858 bool Method::is_static_initializer() const { 859 // For classfiles version 51 or greater, ensure that the clinit method is 860 // static. Non-static methods with the name "<clinit>" are not static 861 // initializers. (older classfiles exempted for backward compatibility) 862 return name() == vmSymbols::class_initializer_name() && 863 has_valid_initializer_flags(); 864 } 865 866 bool Method::is_object_initializer() const { 867 return name() == vmSymbols::object_initializer_name(); 868 } 869 870 bool Method::needs_clinit_barrier() const { 871 return is_static() && !method_holder()->is_initialized(); 872 } 873 874 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) { 875 int length = method->checked_exceptions_length(); 876 if (length == 0) { // common case 877 return objArrayHandle(THREAD, Universe::the_empty_class_array()); 878 } else { 879 methodHandle h_this(THREAD, method); 880 objArrayOop m_oop = oopFactory::new_objArray(vmClasses::Class_klass(), length, CHECK_(objArrayHandle())); 881 objArrayHandle mirrors (THREAD, m_oop); 882 for (int i = 0; i < length; i++) { 883 CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe 884 Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle())); 885 if (log_is_enabled(Warning, exceptions) && 886 !k->is_subclass_of(vmClasses::Throwable_klass())) { 887 ResourceMark rm(THREAD); 888 log_warning(exceptions)( 889 "Class %s in throws clause of method %s is not a subtype of class java.lang.Throwable", 890 k->external_name(), method->external_name()); 891 } 892 mirrors->obj_at_put(i, k->java_mirror()); 893 } 894 return mirrors; 895 } 896 }; 897 898 899 int Method::line_number_from_bci(int bci) const { 900 int best_bci = 0; 901 int best_line = -1; 902 if (bci == SynchronizationEntryBCI) bci = 0; 903 if (0 <= bci && bci < code_size() && has_linenumber_table()) { 904 // The line numbers are a short array of 2-tuples [start_pc, line_number]. 905 // Not necessarily sorted and not necessarily one-to-one. 906 CompressedLineNumberReadStream stream(compressed_linenumber_table()); 907 while (stream.read_pair()) { 908 if (stream.bci() == bci) { 909 // perfect match 910 return stream.line(); 911 } else { 912 // update best_bci/line 913 if (stream.bci() < bci && stream.bci() >= best_bci) { 914 best_bci = stream.bci(); 915 best_line = stream.line(); 916 } 917 } 918 } 919 } 920 return best_line; 921 } 922 923 924 bool Method::is_klass_loaded_by_klass_index(int klass_index) const { 925 if( constants()->tag_at(klass_index).is_unresolved_klass() ) { 926 Thread *thread = Thread::current(); 927 Symbol* klass_name = constants()->klass_name_at(klass_index); 928 Handle loader(thread, method_holder()->class_loader()); 929 Handle prot (thread, method_holder()->protection_domain()); 930 return SystemDictionary::find_instance_klass(thread, klass_name, loader, prot) != nullptr; 931 } else { 932 return true; 933 } 934 } 935 936 937 bool Method::is_klass_loaded(int refinfo_index, Bytecodes::Code bc, bool must_be_resolved) const { 938 int klass_index = constants()->klass_ref_index_at(refinfo_index, bc); 939 if (must_be_resolved) { 940 // Make sure klass is resolved in constantpool. 941 if (constants()->tag_at(klass_index).is_unresolved_klass()) return false; 942 } 943 return is_klass_loaded_by_klass_index(klass_index); 944 } 945 946 947 void Method::set_native_function(address function, bool post_event_flag) { 948 assert(function != nullptr, "use clear_native_function to unregister natives"); 949 assert(!is_special_native_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), ""); 950 address* native_function = native_function_addr(); 951 952 // We can see racers trying to place the same native function into place. Once 953 // is plenty. 954 address current = *native_function; 955 if (current == function) return; 956 if (post_event_flag && JvmtiExport::should_post_native_method_bind() && 957 function != nullptr) { 958 // native_method_throw_unsatisfied_link_error_entry() should only 959 // be passed when post_event_flag is false. 960 assert(function != 961 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), 962 "post_event_flag mismatch"); 963 964 // post the bind event, and possible change the bind function 965 JvmtiExport::post_native_method_bind(this, &function); 966 } 967 *native_function = function; 968 // This function can be called more than once. We must make sure that we always 969 // use the latest registered method -> check if a stub already has been generated. 970 // If so, we have to make it not_entrant. 971 nmethod* nm = code(); // Put it into local variable to guard against concurrent updates 972 if (nm != nullptr) { 973 nm->make_not_entrant(); 974 } 975 } 976 977 978 bool Method::has_native_function() const { 979 if (is_special_native_intrinsic()) 980 return false; // special-cased in SharedRuntime::generate_native_wrapper 981 address func = native_function(); 982 return (func != nullptr && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry()); 983 } 984 985 986 void Method::clear_native_function() { 987 // Note: is_method_handle_intrinsic() is allowed here. 988 set_native_function( 989 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), 990 !native_bind_event_is_interesting); 991 this->unlink_code(); 992 } 993 994 995 void Method::set_signature_handler(address handler) { 996 address* signature_handler = signature_handler_addr(); 997 *signature_handler = handler; 998 } 999 1000 1001 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) { 1002 assert(reason != nullptr, "must provide a reason"); 1003 if (PrintCompilation && report) { 1004 ttyLocker ttyl; 1005 tty->print("made not %scompilable on ", is_osr ? "OSR " : ""); 1006 if (comp_level == CompLevel_all) { 1007 tty->print("all levels "); 1008 } else { 1009 tty->print("level %d ", comp_level); 1010 } 1011 this->print_short_name(tty); 1012 int size = this->code_size(); 1013 if (size > 0) { 1014 tty->print(" (%d bytes)", size); 1015 } 1016 if (reason != nullptr) { 1017 tty->print(" %s", reason); 1018 } 1019 tty->cr(); 1020 } 1021 if ((TraceDeoptimization || LogCompilation) && (xtty != nullptr)) { 1022 ttyLocker ttyl; 1023 xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'", 1024 os::current_thread_id(), is_osr, comp_level); 1025 if (reason != nullptr) { 1026 xtty->print(" reason=\'%s\'", reason); 1027 } 1028 xtty->method(this); 1029 xtty->stamp(); 1030 xtty->end_elem(); 1031 } 1032 } 1033 1034 bool Method::is_always_compilable() const { 1035 // Generated adapters must be compiled 1036 if (is_special_native_intrinsic() && is_synthetic()) { 1037 assert(!is_not_c1_compilable(), "sanity check"); 1038 assert(!is_not_c2_compilable(), "sanity check"); 1039 return true; 1040 } 1041 1042 return false; 1043 } 1044 1045 bool Method::is_not_compilable(int comp_level) const { 1046 if (number_of_breakpoints() > 0) 1047 return true; 1048 if (is_always_compilable()) 1049 return false; 1050 if (comp_level == CompLevel_any) 1051 return is_not_c1_compilable() && is_not_c2_compilable(); 1052 if (is_c1_compile(comp_level)) 1053 return is_not_c1_compilable(); 1054 if (is_c2_compile(comp_level)) 1055 return is_not_c2_compilable(); 1056 return false; 1057 } 1058 1059 // call this when compiler finds that this method is not compilable 1060 void Method::set_not_compilable(const char* reason, int comp_level, bool report) { 1061 if (is_always_compilable()) { 1062 // Don't mark a method which should be always compilable 1063 return; 1064 } 1065 print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason); 1066 if (comp_level == CompLevel_all) { 1067 set_is_not_c1_compilable(); 1068 set_is_not_c2_compilable(); 1069 } else { 1070 if (is_c1_compile(comp_level)) 1071 set_is_not_c1_compilable(); 1072 if (is_c2_compile(comp_level)) 1073 set_is_not_c2_compilable(); 1074 } 1075 assert(!CompilationPolicy::can_be_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check"); 1076 } 1077 1078 bool Method::is_not_osr_compilable(int comp_level) const { 1079 if (is_not_compilable(comp_level)) 1080 return true; 1081 if (comp_level == CompLevel_any) 1082 return is_not_c1_osr_compilable() && is_not_c2_osr_compilable(); 1083 if (is_c1_compile(comp_level)) 1084 return is_not_c1_osr_compilable(); 1085 if (is_c2_compile(comp_level)) 1086 return is_not_c2_osr_compilable(); 1087 return false; 1088 } 1089 1090 void Method::set_not_osr_compilable(const char* reason, int comp_level, bool report) { 1091 print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason); 1092 if (comp_level == CompLevel_all) { 1093 set_is_not_c1_osr_compilable(); 1094 set_is_not_c2_osr_compilable(); 1095 } else { 1096 if (is_c1_compile(comp_level)) 1097 set_is_not_c1_osr_compilable(); 1098 if (is_c2_compile(comp_level)) 1099 set_is_not_c2_osr_compilable(); 1100 } 1101 assert(!CompilationPolicy::can_be_osr_compiled(methodHandle(Thread::current(), this), comp_level), "sanity check"); 1102 } 1103 1104 // Revert to using the interpreter and clear out the nmethod 1105 void Method::clear_code() { 1106 // this may be null if c2i adapters have not been made yet 1107 // Only should happen at allocate time. 1108 if (adapter() == nullptr) { 1109 _from_compiled_entry = nullptr; 1110 } else { 1111 _from_compiled_entry = adapter()->get_c2i_entry(); 1112 } 1113 OrderAccess::storestore(); 1114 _from_interpreted_entry = _i2i_entry; 1115 OrderAccess::storestore(); 1116 _code = nullptr; 1117 } 1118 1119 void Method::unlink_code(nmethod *compare) { 1120 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag); 1121 // We need to check if either the _code or _from_compiled_code_entry_point 1122 // refer to this nmethod because there is a race in setting these two fields 1123 // in Method* as seen in bugid 4947125. 1124 if (code() == compare || 1125 from_compiled_entry() == compare->verified_entry_point()) { 1126 clear_code(); 1127 } 1128 } 1129 1130 void Method::unlink_code() { 1131 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag); 1132 clear_code(); 1133 } 1134 1135 #if INCLUDE_CDS 1136 // Called by class data sharing to remove any entry points (which are not shared) 1137 void Method::unlink_method() { 1138 assert(CDSConfig::is_dumping_archive(), "sanity"); 1139 _code = nullptr; 1140 _adapter = nullptr; 1141 _i2i_entry = nullptr; 1142 _from_compiled_entry = nullptr; 1143 _from_interpreted_entry = nullptr; 1144 1145 if (is_native()) { 1146 *native_function_addr() = nullptr; 1147 set_signature_handler(nullptr); 1148 } 1149 NOT_PRODUCT(set_compiled_invocation_count(0);) 1150 1151 clear_method_data(); 1152 clear_method_counters(); 1153 remove_unshareable_flags(); 1154 } 1155 1156 void Method::remove_unshareable_flags() { 1157 // clear all the flags that shouldn't be in the archived version 1158 assert(!is_old(), "must be"); 1159 assert(!is_obsolete(), "must be"); 1160 assert(!is_deleted(), "must be"); 1161 1162 set_is_prefixed_native(false); 1163 set_queued_for_compilation(false); 1164 set_is_not_c2_compilable(false); 1165 set_is_not_c1_compilable(false); 1166 set_is_not_c2_osr_compilable(false); 1167 set_on_stack_flag(false); 1168 } 1169 #endif 1170 1171 // Called when the method_holder is getting linked. Setup entrypoints so the method 1172 // is ready to be called from interpreter, compiler, and vtables. 1173 void Method::link_method(const methodHandle& h_method, TRAPS) { 1174 if (log_is_enabled(Info, perf, class, link)) { 1175 ClassLoader::perf_ik_link_methods_count()->inc(); 1176 } 1177 1178 // If the code cache is full, we may reenter this function for the 1179 // leftover methods that weren't linked. 1180 if (adapter() != nullptr) { 1181 return; 1182 } 1183 assert( _code == nullptr, "nothing compiled yet" ); 1184 1185 // Setup interpreter entrypoint 1186 assert(this == h_method(), "wrong h_method()" ); 1187 1188 assert(adapter() == nullptr, "init'd to null"); 1189 address entry = Interpreter::entry_for_method(h_method); 1190 assert(entry != nullptr, "interpreter entry must be non-null"); 1191 // Sets both _i2i_entry and _from_interpreted_entry 1192 set_interpreter_entry(entry); 1193 1194 // Don't overwrite already registered native entries. 1195 if (is_native() && !has_native_function()) { 1196 set_native_function( 1197 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), 1198 !native_bind_event_is_interesting); 1199 } 1200 1201 // Setup compiler entrypoint. This is made eagerly, so we do not need 1202 // special handling of vtables. An alternative is to make adapters more 1203 // lazily by calling make_adapter() from from_compiled_entry() for the 1204 // normal calls. For vtable calls life gets more complicated. When a 1205 // call-site goes mega-morphic we need adapters in all methods which can be 1206 // called from the vtable. We need adapters on such methods that get loaded 1207 // later. Ditto for mega-morphic itable calls. If this proves to be a 1208 // problem we'll make these lazily later. 1209 (void) make_adapters(h_method, CHECK); 1210 1211 // ONLY USE the h_method now as make_adapter may have blocked 1212 1213 if (h_method->is_continuation_native_intrinsic()) { 1214 _from_interpreted_entry = nullptr; 1215 _from_compiled_entry = nullptr; 1216 _i2i_entry = nullptr; 1217 if (Continuations::enabled()) { 1218 assert(!Threads::is_vm_complete(), "should only be called during vm init"); 1219 AdapterHandlerLibrary::create_native_wrapper(h_method); 1220 if (!h_method->has_compiled_code()) { 1221 THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), "Initial size of CodeCache is too small"); 1222 } 1223 assert(_from_interpreted_entry == get_i2c_entry(), "invariant"); 1224 } 1225 } 1226 } 1227 1228 address Method::make_adapters(const methodHandle& mh, TRAPS) { 1229 PerfTraceTime timer(ClassLoader::perf_method_adapters_time()); 1230 1231 // Adapters for compiled code are made eagerly here. They are fairly 1232 // small (generally < 100 bytes) and quick to make (and cached and shared) 1233 // so making them eagerly shouldn't be too expensive. 1234 AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh); 1235 if (adapter == nullptr ) { 1236 if (!is_init_completed()) { 1237 // Don't throw exceptions during VM initialization because java.lang.* classes 1238 // might not have been initialized, causing problems when constructing the 1239 // Java exception object. 1240 vm_exit_during_initialization("Out of space in CodeCache for adapters"); 1241 } else { 1242 THROW_MSG_NULL(vmSymbols::java_lang_OutOfMemoryError(), "Out of space in CodeCache for adapters"); 1243 } 1244 } 1245 1246 mh->set_adapter_entry(adapter); 1247 mh->_from_compiled_entry = adapter->get_c2i_entry(); 1248 return adapter->get_c2i_entry(); 1249 } 1250 1251 // The verified_code_entry() must be called when a invoke is resolved 1252 // on this method. 1253 1254 // It returns the compiled code entry point, after asserting not null. 1255 // This function is called after potential safepoints so that nmethod 1256 // or adapter that it points to is still live and valid. 1257 // This function must not hit a safepoint! 1258 address Method::verified_code_entry() { 1259 debug_only(NoSafepointVerifier nsv;) 1260 assert(_from_compiled_entry != nullptr, "must be set"); 1261 return _from_compiled_entry; 1262 } 1263 1264 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all 1265 // (could be racing a deopt). 1266 // Not inline to avoid circular ref. 1267 bool Method::check_code() const { 1268 // cached in a register or local. There's a race on the value of the field. 1269 nmethod *code = Atomic::load_acquire(&_code); 1270 return code == nullptr || (code->method() == nullptr) || (code->method() == (Method*)this && !code->is_osr_method()); 1271 } 1272 1273 // Install compiled code. Instantly it can execute. 1274 void Method::set_code(const methodHandle& mh, nmethod *code) { 1275 assert_lock_strong(NMethodState_lock); 1276 assert( code, "use clear_code to remove code" ); 1277 assert( mh->check_code(), "" ); 1278 1279 guarantee(mh->adapter() != nullptr, "Adapter blob must already exist!"); 1280 1281 // These writes must happen in this order, because the interpreter will 1282 // directly jump to from_interpreted_entry which jumps to an i2c adapter 1283 // which jumps to _from_compiled_entry. 1284 mh->_code = code; // Assign before allowing compiled code to exec 1285 1286 int comp_level = code->comp_level(); 1287 // In theory there could be a race here. In practice it is unlikely 1288 // and not worth worrying about. 1289 if (comp_level > mh->highest_comp_level()) { 1290 mh->set_highest_comp_level(comp_level); 1291 } 1292 1293 OrderAccess::storestore(); 1294 mh->_from_compiled_entry = code->verified_entry_point(); 1295 OrderAccess::storestore(); 1296 1297 if (mh->is_continuation_native_intrinsic()) { 1298 assert(mh->_from_interpreted_entry == nullptr, "initialized incorrectly"); // see link_method 1299 1300 if (mh->is_continuation_enter_intrinsic()) { 1301 // This is the entry used when we're in interpreter-only mode; see InterpreterMacroAssembler::jump_from_interpreted 1302 mh->_i2i_entry = ContinuationEntry::interpreted_entry(); 1303 } else if (mh->is_continuation_yield_intrinsic()) { 1304 mh->_i2i_entry = mh->get_i2c_entry(); 1305 } else { 1306 guarantee(false, "Unknown Continuation native intrinsic"); 1307 } 1308 // This must come last, as it is what's tested in LinkResolver::resolve_static_call 1309 Atomic::release_store(&mh->_from_interpreted_entry , mh->get_i2c_entry()); 1310 } else if (!mh->is_method_handle_intrinsic()) { 1311 // Instantly compiled code can execute. 1312 mh->_from_interpreted_entry = mh->get_i2c_entry(); 1313 } 1314 } 1315 1316 1317 bool Method::is_overridden_in(Klass* k) const { 1318 InstanceKlass* ik = InstanceKlass::cast(k); 1319 1320 if (ik->is_interface()) return false; 1321 1322 // If method is an interface, we skip it - except if it 1323 // is a miranda method 1324 if (method_holder()->is_interface()) { 1325 // Check that method is not a miranda method 1326 if (ik->lookup_method(name(), signature()) == nullptr) { 1327 // No implementation exist - so miranda method 1328 return false; 1329 } 1330 return true; 1331 } 1332 1333 assert(ik->is_subclass_of(method_holder()), "should be subklass"); 1334 if (!has_vtable_index()) { 1335 return false; 1336 } else { 1337 Method* vt_m = ik->method_at_vtable(vtable_index()); 1338 return vt_m != this; 1339 } 1340 } 1341 1342 1343 // give advice about whether this Method* should be cached or not 1344 bool Method::should_not_be_cached() const { 1345 if (is_old()) { 1346 // This method has been redefined. It is either EMCP or obsolete 1347 // and we don't want to cache it because that would pin the method 1348 // down and prevent it from being collectible if and when it 1349 // finishes executing. 1350 return true; 1351 } 1352 1353 // caching this method should be just fine 1354 return false; 1355 } 1356 1357 1358 /** 1359 * Returns true if this is one of the specially treated methods for 1360 * security related stack walks (like Reflection.getCallerClass). 1361 */ 1362 bool Method::is_ignored_by_security_stack_walk() const { 1363 if (intrinsic_id() == vmIntrinsics::_invoke) { 1364 // This is Method.invoke() -- ignore it 1365 return true; 1366 } 1367 if (method_holder()->is_subclass_of(vmClasses::reflect_MethodAccessorImpl_klass())) { 1368 // This is an auxiliary frame -- ignore it 1369 return true; 1370 } 1371 if (is_method_handle_intrinsic() || is_compiled_lambda_form()) { 1372 // This is an internal adapter frame for method handles -- ignore it 1373 return true; 1374 } 1375 return false; 1376 } 1377 1378 1379 // Constant pool structure for invoke methods: 1380 enum { 1381 _imcp_invoke_name = 1, // utf8: 'invokeExact', etc. 1382 _imcp_invoke_signature, // utf8: (variable Symbol*) 1383 _imcp_limit 1384 }; 1385 1386 // Test if this method is an MH adapter frame generated by Java code. 1387 // Cf. java/lang/invoke/InvokerBytecodeGenerator 1388 bool Method::is_compiled_lambda_form() const { 1389 return intrinsic_id() == vmIntrinsics::_compiledLambdaForm; 1390 } 1391 1392 // Test if this method is an internal MH primitive method. 1393 bool Method::is_method_handle_intrinsic() const { 1394 vmIntrinsics::ID iid = intrinsic_id(); 1395 return (MethodHandles::is_signature_polymorphic(iid) && 1396 MethodHandles::is_signature_polymorphic_intrinsic(iid)); 1397 } 1398 1399 bool Method::has_member_arg() const { 1400 vmIntrinsics::ID iid = intrinsic_id(); 1401 return (MethodHandles::is_signature_polymorphic(iid) && 1402 MethodHandles::has_member_arg(iid)); 1403 } 1404 1405 // Make an instance of a signature-polymorphic internal MH primitive. 1406 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid, 1407 Symbol* signature, 1408 TRAPS) { 1409 ResourceMark rm(THREAD); 1410 methodHandle empty; 1411 1412 InstanceKlass* holder = vmClasses::MethodHandle_klass(); 1413 Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid); 1414 assert(iid == MethodHandles::signature_polymorphic_name_id(name), ""); 1415 1416 log_info(methodhandles)("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string()); 1417 1418 // invariant: cp->symbol_at_put is preceded by a refcount increment (more usually a lookup) 1419 name->increment_refcount(); 1420 signature->increment_refcount(); 1421 1422 int cp_length = _imcp_limit; 1423 ClassLoaderData* loader_data = holder->class_loader_data(); 1424 constantPoolHandle cp; 1425 { 1426 ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty)); 1427 cp = constantPoolHandle(THREAD, cp_oop); 1428 } 1429 cp->copy_fields(holder->constants()); 1430 cp->set_pool_holder(holder); 1431 cp->symbol_at_put(_imcp_invoke_name, name); 1432 cp->symbol_at_put(_imcp_invoke_signature, signature); 1433 cp->set_has_preresolution(); 1434 1435 // decide on access bits: public or not? 1436 int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL); 1437 bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid); 1438 if (must_be_static) flags_bits |= JVM_ACC_STATIC; 1439 assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods"); 1440 1441 methodHandle m; 1442 { 1443 InlineTableSizes sizes; 1444 Method* m_oop = Method::allocate(loader_data, 0, 1445 accessFlags_from(flags_bits), &sizes, 1446 ConstMethod::NORMAL, 1447 name, 1448 CHECK_(empty)); 1449 m = methodHandle(THREAD, m_oop); 1450 } 1451 m->set_constants(cp()); 1452 m->set_name_index(_imcp_invoke_name); 1453 m->set_signature_index(_imcp_invoke_signature); 1454 assert(MethodHandles::is_signature_polymorphic_name(m->name()), ""); 1455 assert(m->signature() == signature, ""); 1456 m->constMethod()->compute_from_signature(signature, must_be_static); 1457 m->init_intrinsic_id(klass_id_for_intrinsics(m->method_holder())); 1458 assert(m->is_method_handle_intrinsic(), ""); 1459 #ifdef ASSERT 1460 if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id())) m->print(); 1461 assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker"); 1462 assert(m->intrinsic_id() == iid, "correctly predicted iid"); 1463 #endif //ASSERT 1464 1465 // Finally, set up its entry points. 1466 assert(m->can_be_statically_bound(), ""); 1467 m->set_vtable_index(Method::nonvirtual_vtable_index); 1468 m->link_method(m, CHECK_(empty)); 1469 1470 if (iid == vmIntrinsics::_linkToNative) { 1471 m->set_interpreter_entry(m->adapter()->get_i2c_entry()); 1472 } 1473 if (log_is_enabled(Debug, methodhandles)) { 1474 LogTarget(Debug, methodhandles) lt; 1475 LogStream ls(lt); 1476 m->print_on(&ls); 1477 } 1478 1479 return m; 1480 } 1481 1482 Klass* Method::check_non_bcp_klass(Klass* klass) { 1483 if (klass != nullptr && klass->class_loader() != nullptr) { 1484 if (klass->is_objArray_klass()) 1485 klass = ObjArrayKlass::cast(klass)->bottom_klass(); 1486 return klass; 1487 } 1488 return nullptr; 1489 } 1490 1491 1492 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length, 1493 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) { 1494 // Code below does not work for native methods - they should never get rewritten anyway 1495 assert(!m->is_native(), "cannot rewrite native methods"); 1496 // Allocate new Method* 1497 AccessFlags flags = m->access_flags(); 1498 1499 ConstMethod* cm = m->constMethod(); 1500 int checked_exceptions_len = cm->checked_exceptions_length(); 1501 int localvariable_len = cm->localvariable_table_length(); 1502 int exception_table_len = cm->exception_table_length(); 1503 int method_parameters_len = cm->method_parameters_length(); 1504 int method_annotations_len = cm->method_annotations_length(); 1505 int parameter_annotations_len = cm->parameter_annotations_length(); 1506 int type_annotations_len = cm->type_annotations_length(); 1507 int default_annotations_len = cm->default_annotations_length(); 1508 1509 InlineTableSizes sizes( 1510 localvariable_len, 1511 new_compressed_linenumber_size, 1512 exception_table_len, 1513 checked_exceptions_len, 1514 method_parameters_len, 1515 cm->generic_signature_index(), 1516 method_annotations_len, 1517 parameter_annotations_len, 1518 type_annotations_len, 1519 default_annotations_len, 1520 0); 1521 1522 ClassLoaderData* loader_data = m->method_holder()->class_loader_data(); 1523 Method* newm_oop = Method::allocate(loader_data, 1524 new_code_length, 1525 flags, 1526 &sizes, 1527 m->method_type(), 1528 m->name(), 1529 CHECK_(methodHandle())); 1530 methodHandle newm (THREAD, newm_oop); 1531 1532 // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod* 1533 ConstMethod* newcm = newm->constMethod(); 1534 int new_const_method_size = newm->constMethod()->size(); 1535 1536 // This works because the source and target are both Methods. Some compilers 1537 // (e.g., clang) complain that the target vtable pointer will be stomped, 1538 // so cast away newm()'s and m()'s Methodness. 1539 memcpy((void*)newm(), (void*)m(), sizeof(Method)); 1540 1541 // Create shallow copy of ConstMethod. 1542 memcpy(newcm, m->constMethod(), sizeof(ConstMethod)); 1543 1544 // Reset correct method/const method, method size, and parameter info 1545 newm->set_constMethod(newcm); 1546 newm->constMethod()->set_code_size(new_code_length); 1547 newm->constMethod()->set_constMethod_size(new_const_method_size); 1548 assert(newm->code_size() == new_code_length, "check"); 1549 assert(newm->method_parameters_length() == method_parameters_len, "check"); 1550 assert(newm->checked_exceptions_length() == checked_exceptions_len, "check"); 1551 assert(newm->exception_table_length() == exception_table_len, "check"); 1552 assert(newm->localvariable_table_length() == localvariable_len, "check"); 1553 // Copy new byte codes 1554 memcpy(newm->code_base(), new_code, new_code_length); 1555 // Copy line number table 1556 if (new_compressed_linenumber_size > 0) { 1557 memcpy(newm->compressed_linenumber_table(), 1558 new_compressed_linenumber_table, 1559 new_compressed_linenumber_size); 1560 } 1561 // Copy method_parameters 1562 if (method_parameters_len > 0) { 1563 memcpy(newm->method_parameters_start(), 1564 m->method_parameters_start(), 1565 method_parameters_len * sizeof(MethodParametersElement)); 1566 } 1567 // Copy checked_exceptions 1568 if (checked_exceptions_len > 0) { 1569 memcpy(newm->checked_exceptions_start(), 1570 m->checked_exceptions_start(), 1571 checked_exceptions_len * sizeof(CheckedExceptionElement)); 1572 } 1573 // Copy exception table 1574 if (exception_table_len > 0) { 1575 memcpy(newm->exception_table_start(), 1576 m->exception_table_start(), 1577 exception_table_len * sizeof(ExceptionTableElement)); 1578 } 1579 // Copy local variable number table 1580 if (localvariable_len > 0) { 1581 memcpy(newm->localvariable_table_start(), 1582 m->localvariable_table_start(), 1583 localvariable_len * sizeof(LocalVariableTableElement)); 1584 } 1585 // Copy stackmap table 1586 if (m->has_stackmap_table()) { 1587 int code_attribute_length = m->stackmap_data()->length(); 1588 Array<u1>* stackmap_data = 1589 MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_(methodHandle())); 1590 memcpy((void*)stackmap_data->adr_at(0), 1591 (void*)m->stackmap_data()->adr_at(0), code_attribute_length); 1592 newm->set_stackmap_data(stackmap_data); 1593 } 1594 1595 // copy annotations over to new method 1596 newcm->copy_annotations_from(loader_data, cm, CHECK_(methodHandle())); 1597 return newm; 1598 } 1599 1600 vmSymbolID Method::klass_id_for_intrinsics(const Klass* holder) { 1601 // if loader is not the default loader (i.e., non-null), we can't know the intrinsics 1602 // because we are not loading from core libraries 1603 // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar 1604 // which does not use the class default class loader so we check for its loader here 1605 const InstanceKlass* ik = InstanceKlass::cast(holder); 1606 if ((ik->class_loader() != nullptr) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) { 1607 return vmSymbolID::NO_SID; // regardless of name, no intrinsics here 1608 } 1609 1610 // see if the klass name is well-known: 1611 Symbol* klass_name = ik->name(); 1612 vmSymbolID id = vmSymbols::find_sid(klass_name); 1613 if (id != vmSymbolID::NO_SID && vmIntrinsics::class_has_intrinsics(id)) { 1614 return id; 1615 } else { 1616 return vmSymbolID::NO_SID; 1617 } 1618 } 1619 1620 void Method::init_intrinsic_id(vmSymbolID klass_id) { 1621 assert(_intrinsic_id == static_cast<int>(vmIntrinsics::_none), "do this just once"); 1622 const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte)); 1623 assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size"); 1624 assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), ""); 1625 1626 // the klass name is well-known: 1627 assert(klass_id == klass_id_for_intrinsics(method_holder()), "must be"); 1628 assert(klass_id != vmSymbolID::NO_SID, "caller responsibility"); 1629 1630 // ditto for method and signature: 1631 vmSymbolID name_id = vmSymbols::find_sid(name()); 1632 if (klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle) 1633 && klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle) 1634 && name_id == vmSymbolID::NO_SID) { 1635 return; 1636 } 1637 vmSymbolID sig_id = vmSymbols::find_sid(signature()); 1638 if (klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle) 1639 && klass_id != VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle) 1640 && sig_id == vmSymbolID::NO_SID) { 1641 return; 1642 } 1643 jshort flags = access_flags().as_short(); 1644 1645 vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags); 1646 if (id != vmIntrinsics::_none) { 1647 set_intrinsic_id(id); 1648 if (id == vmIntrinsics::_Class_cast) { 1649 // Even if the intrinsic is rejected, we want to inline this simple method. 1650 set_force_inline(); 1651 } 1652 return; 1653 } 1654 1655 // A few slightly irregular cases: 1656 switch (klass_id) { 1657 // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle 1658 case VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle): 1659 case VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle): 1660 if (!is_native()) break; 1661 id = MethodHandles::signature_polymorphic_name_id(method_holder(), name()); 1662 if (is_static() != MethodHandles::is_signature_polymorphic_static(id)) 1663 id = vmIntrinsics::_none; 1664 break; 1665 1666 default: 1667 break; 1668 } 1669 1670 if (id != vmIntrinsics::_none) { 1671 // Set up its iid. It is an alias method. 1672 set_intrinsic_id(id); 1673 return; 1674 } 1675 } 1676 1677 bool Method::load_signature_classes(const methodHandle& m, TRAPS) { 1678 if (!THREAD->can_call_java()) { 1679 // There is nothing useful this routine can do from within the Compile thread. 1680 // Hopefully, the signature contains only well-known classes. 1681 // We could scan for this and return true/false, but the caller won't care. 1682 return false; 1683 } 1684 bool sig_is_loaded = true; 1685 ResourceMark rm(THREAD); 1686 for (ResolvingSignatureStream ss(m()); !ss.is_done(); ss.next()) { 1687 if (ss.is_reference()) { 1688 // load everything, including arrays "[Lfoo;" 1689 Klass* klass = ss.as_klass(SignatureStream::ReturnNull, THREAD); 1690 // We are loading classes eagerly. If a ClassNotFoundException or 1691 // a LinkageError was generated, be sure to ignore it. 1692 if (HAS_PENDING_EXCEPTION) { 1693 if (PENDING_EXCEPTION->is_a(vmClasses::ClassNotFoundException_klass()) || 1694 PENDING_EXCEPTION->is_a(vmClasses::LinkageError_klass())) { 1695 CLEAR_PENDING_EXCEPTION; 1696 } else { 1697 return false; 1698 } 1699 } 1700 if( klass == nullptr) { sig_is_loaded = false; } 1701 } 1702 } 1703 return sig_is_loaded; 1704 } 1705 1706 // Exposed so field engineers can debug VM 1707 void Method::print_short_name(outputStream* st) const { 1708 ResourceMark rm; 1709 #ifdef PRODUCT 1710 st->print(" %s::", method_holder()->external_name()); 1711 #else 1712 st->print(" %s::", method_holder()->internal_name()); 1713 #endif 1714 name()->print_symbol_on(st); 1715 if (WizardMode) signature()->print_symbol_on(st); 1716 else if (MethodHandles::is_signature_polymorphic(intrinsic_id())) 1717 MethodHandles::print_as_basic_type_signature_on(st, signature()); 1718 } 1719 1720 // Comparer for sorting an object array containing 1721 // Method*s. 1722 static int method_comparator(Method* a, Method* b) { 1723 return a->name()->fast_compare(b->name()); 1724 } 1725 1726 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array 1727 // default_methods also uses this without the ordering for fast find_method 1728 void Method::sort_methods(Array<Method*>* methods, bool set_idnums, method_comparator_func func) { 1729 int length = methods->length(); 1730 if (length > 1) { 1731 if (func == nullptr) { 1732 func = method_comparator; 1733 } 1734 { 1735 NoSafepointVerifier nsv; 1736 QuickSort::sort(methods->data(), length, func); 1737 } 1738 // Reset method ordering 1739 if (set_idnums) { 1740 for (u2 i = 0; i < length; i++) { 1741 Method* m = methods->at(i); 1742 m->set_method_idnum(i); 1743 m->set_orig_method_idnum(i); 1744 } 1745 } 1746 } 1747 } 1748 1749 //----------------------------------------------------------------------------------- 1750 // Non-product code unless JVM/TI needs it 1751 1752 #if !defined(PRODUCT) || INCLUDE_JVMTI 1753 class SignatureTypePrinter : public SignatureTypeNames { 1754 private: 1755 outputStream* _st; 1756 bool _use_separator; 1757 1758 void type_name(const char* name) { 1759 if (_use_separator) _st->print(", "); 1760 _st->print("%s", name); 1761 _use_separator = true; 1762 } 1763 1764 public: 1765 SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) { 1766 _st = st; 1767 _use_separator = false; 1768 } 1769 1770 void print_parameters() { _use_separator = false; do_parameters_on(this); } 1771 void print_returntype() { _use_separator = false; do_type(return_type()); } 1772 }; 1773 1774 1775 void Method::print_name(outputStream* st) const { 1776 Thread *thread = Thread::current(); 1777 ResourceMark rm(thread); 1778 st->print("%s ", is_static() ? "static" : "virtual"); 1779 if (WizardMode) { 1780 st->print("%s.", method_holder()->internal_name()); 1781 name()->print_symbol_on(st); 1782 signature()->print_symbol_on(st); 1783 } else { 1784 SignatureTypePrinter sig(signature(), st); 1785 sig.print_returntype(); 1786 st->print(" %s.", method_holder()->internal_name()); 1787 name()->print_symbol_on(st); 1788 st->print("("); 1789 sig.print_parameters(); 1790 st->print(")"); 1791 } 1792 } 1793 #endif // !PRODUCT || INCLUDE_JVMTI 1794 1795 1796 void Method::print_codes_on(outputStream* st, int flags) const { 1797 print_codes_on(0, code_size(), st, flags); 1798 } 1799 1800 void Method::print_codes_on(int from, int to, outputStream* st, int flags) const { 1801 Thread *thread = Thread::current(); 1802 ResourceMark rm(thread); 1803 methodHandle mh (thread, (Method*)this); 1804 BytecodeTracer::print_method_codes(mh, from, to, st, flags); 1805 } 1806 1807 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) { 1808 _bci = 0; 1809 _line = 0; 1810 }; 1811 1812 bool CompressedLineNumberReadStream::read_pair() { 1813 jubyte next = read_byte(); 1814 // Check for terminator 1815 if (next == 0) return false; 1816 if (next == 0xFF) { 1817 // Escape character, regular compression used 1818 _bci += read_signed_int(); 1819 _line += read_signed_int(); 1820 } else { 1821 // Single byte compression used 1822 _bci += next >> 3; 1823 _line += next & 0x7; 1824 } 1825 return true; 1826 } 1827 1828 #if INCLUDE_JVMTI 1829 1830 Bytecodes::Code Method::orig_bytecode_at(int bci) const { 1831 BreakpointInfo* bp = method_holder()->breakpoints(); 1832 for (; bp != nullptr; bp = bp->next()) { 1833 if (bp->match(this, bci)) { 1834 return bp->orig_bytecode(); 1835 } 1836 } 1837 { 1838 ResourceMark rm; 1839 fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci); 1840 } 1841 return Bytecodes::_shouldnotreachhere; 1842 } 1843 1844 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) { 1845 assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way"); 1846 BreakpointInfo* bp = method_holder()->breakpoints(); 1847 for (; bp != nullptr; bp = bp->next()) { 1848 if (bp->match(this, bci)) { 1849 bp->set_orig_bytecode(code); 1850 // and continue, in case there is more than one 1851 } 1852 } 1853 } 1854 1855 void Method::set_breakpoint(int bci) { 1856 InstanceKlass* ik = method_holder(); 1857 BreakpointInfo *bp = new BreakpointInfo(this, bci); 1858 bp->set_next(ik->breakpoints()); 1859 ik->set_breakpoints(bp); 1860 // do this last: 1861 bp->set(this); 1862 } 1863 1864 static void clear_matches(Method* m, int bci) { 1865 InstanceKlass* ik = m->method_holder(); 1866 BreakpointInfo* prev_bp = nullptr; 1867 BreakpointInfo* next_bp; 1868 for (BreakpointInfo* bp = ik->breakpoints(); bp != nullptr; bp = next_bp) { 1869 next_bp = bp->next(); 1870 // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint). 1871 if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) { 1872 // do this first: 1873 bp->clear(m); 1874 // unhook it 1875 if (prev_bp != nullptr) 1876 prev_bp->set_next(next_bp); 1877 else 1878 ik->set_breakpoints(next_bp); 1879 delete bp; 1880 // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods 1881 // at same location. So we have multiple matching (method_index and bci) 1882 // BreakpointInfo nodes in BreakpointInfo list. We should just delete one 1883 // breakpoint for clear_breakpoint request and keep all other method versions 1884 // BreakpointInfo for future clear_breakpoint request. 1885 // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints) 1886 // which is being called when class is unloaded. We delete all the Breakpoint 1887 // information for all versions of method. We may not correctly restore the original 1888 // bytecode in all method versions, but that is ok. Because the class is being unloaded 1889 // so these methods won't be used anymore. 1890 if (bci >= 0) { 1891 break; 1892 } 1893 } else { 1894 // This one is a keeper. 1895 prev_bp = bp; 1896 } 1897 } 1898 } 1899 1900 void Method::clear_breakpoint(int bci) { 1901 assert(bci >= 0, ""); 1902 clear_matches(this, bci); 1903 } 1904 1905 void Method::clear_all_breakpoints() { 1906 clear_matches(this, -1); 1907 } 1908 1909 #endif // INCLUDE_JVMTI 1910 1911 int Method::invocation_count() const { 1912 MethodCounters* mcs = method_counters(); 1913 MethodData* mdo = method_data(); 1914 if (((mcs != nullptr) ? mcs->invocation_counter()->carry() : false) || 1915 ((mdo != nullptr) ? mdo->invocation_counter()->carry() : false)) { 1916 return InvocationCounter::count_limit; 1917 } else { 1918 return ((mcs != nullptr) ? mcs->invocation_counter()->count() : 0) + 1919 ((mdo != nullptr) ? mdo->invocation_counter()->count() : 0); 1920 } 1921 } 1922 1923 int Method::backedge_count() const { 1924 MethodCounters* mcs = method_counters(); 1925 MethodData* mdo = method_data(); 1926 if (((mcs != nullptr) ? mcs->backedge_counter()->carry() : false) || 1927 ((mdo != nullptr) ? mdo->backedge_counter()->carry() : false)) { 1928 return InvocationCounter::count_limit; 1929 } else { 1930 return ((mcs != nullptr) ? mcs->backedge_counter()->count() : 0) + 1931 ((mdo != nullptr) ? mdo->backedge_counter()->count() : 0); 1932 } 1933 } 1934 1935 int Method::highest_comp_level() const { 1936 const MethodCounters* mcs = method_counters(); 1937 if (mcs != nullptr) { 1938 return mcs->highest_comp_level(); 1939 } else { 1940 return CompLevel_none; 1941 } 1942 } 1943 1944 int Method::highest_osr_comp_level() const { 1945 const MethodCounters* mcs = method_counters(); 1946 if (mcs != nullptr) { 1947 return mcs->highest_osr_comp_level(); 1948 } else { 1949 return CompLevel_none; 1950 } 1951 } 1952 1953 void Method::set_highest_comp_level(int level) { 1954 MethodCounters* mcs = method_counters(); 1955 if (mcs != nullptr) { 1956 mcs->set_highest_comp_level(level); 1957 } 1958 } 1959 1960 void Method::set_highest_osr_comp_level(int level) { 1961 MethodCounters* mcs = method_counters(); 1962 if (mcs != nullptr) { 1963 mcs->set_highest_osr_comp_level(level); 1964 } 1965 } 1966 1967 #if INCLUDE_JVMTI 1968 1969 BreakpointInfo::BreakpointInfo(Method* m, int bci) { 1970 _bci = bci; 1971 _name_index = m->name_index(); 1972 _signature_index = m->signature_index(); 1973 _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci); 1974 if (_orig_bytecode == Bytecodes::_breakpoint) 1975 _orig_bytecode = m->orig_bytecode_at(_bci); 1976 _next = nullptr; 1977 } 1978 1979 void BreakpointInfo::set(Method* method) { 1980 #ifdef ASSERT 1981 { 1982 Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci); 1983 if (code == Bytecodes::_breakpoint) 1984 code = method->orig_bytecode_at(_bci); 1985 assert(orig_bytecode() == code, "original bytecode must be the same"); 1986 } 1987 #endif 1988 Thread *thread = Thread::current(); 1989 *method->bcp_from(_bci) = Bytecodes::_breakpoint; 1990 method->incr_number_of_breakpoints(thread); 1991 { 1992 // Deoptimize all dependents on this method 1993 HandleMark hm(thread); 1994 methodHandle mh(thread, method); 1995 CodeCache::mark_dependents_on_method_for_breakpoint(mh); 1996 } 1997 } 1998 1999 void BreakpointInfo::clear(Method* method) { 2000 *method->bcp_from(_bci) = orig_bytecode(); 2001 assert(method->number_of_breakpoints() > 0, "must not go negative"); 2002 method->decr_number_of_breakpoints(Thread::current()); 2003 } 2004 2005 #endif // INCLUDE_JVMTI 2006 2007 // jmethodID handling 2008 2009 // This is a block allocating object, sort of like JNIHandleBlock, only a 2010 // lot simpler. 2011 // It's allocated on the CHeap because once we allocate a jmethodID, we can 2012 // never get rid of it. 2013 2014 static const int min_block_size = 8; 2015 2016 class JNIMethodBlockNode : public CHeapObj<mtClass> { 2017 friend class JNIMethodBlock; 2018 Method** _methods; 2019 int _number_of_methods; 2020 int _top; 2021 JNIMethodBlockNode* _next; 2022 2023 public: 2024 2025 JNIMethodBlockNode(int num_methods = min_block_size); 2026 2027 ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); } 2028 2029 void ensure_methods(int num_addl_methods) { 2030 if (_top < _number_of_methods) { 2031 num_addl_methods -= _number_of_methods - _top; 2032 if (num_addl_methods <= 0) { 2033 return; 2034 } 2035 } 2036 if (_next == nullptr) { 2037 _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size)); 2038 } else { 2039 _next->ensure_methods(num_addl_methods); 2040 } 2041 } 2042 }; 2043 2044 class JNIMethodBlock : public CHeapObj<mtClass> { 2045 JNIMethodBlockNode _head; 2046 JNIMethodBlockNode *_last_free; 2047 public: 2048 static Method* const _free_method; 2049 2050 JNIMethodBlock(int initial_capacity = min_block_size) 2051 : _head(initial_capacity), _last_free(&_head) {} 2052 2053 void ensure_methods(int num_addl_methods) { 2054 _last_free->ensure_methods(num_addl_methods); 2055 } 2056 2057 Method** add_method(Method* m) { 2058 for (JNIMethodBlockNode* b = _last_free; b != nullptr; b = b->_next) { 2059 if (b->_top < b->_number_of_methods) { 2060 // top points to the next free entry. 2061 int i = b->_top; 2062 b->_methods[i] = m; 2063 b->_top++; 2064 _last_free = b; 2065 return &(b->_methods[i]); 2066 } else if (b->_top == b->_number_of_methods) { 2067 // if the next free entry ran off the block see if there's a free entry 2068 for (int i = 0; i < b->_number_of_methods; i++) { 2069 if (b->_methods[i] == _free_method) { 2070 b->_methods[i] = m; 2071 _last_free = b; 2072 return &(b->_methods[i]); 2073 } 2074 } 2075 // Only check each block once for frees. They're very unlikely. 2076 // Increment top past the end of the block. 2077 b->_top++; 2078 } 2079 // need to allocate a next block. 2080 if (b->_next == nullptr) { 2081 b->_next = _last_free = new JNIMethodBlockNode(); 2082 } 2083 } 2084 guarantee(false, "Should always allocate a free block"); 2085 return nullptr; 2086 } 2087 2088 bool contains(Method** m) { 2089 if (m == nullptr) return false; 2090 for (JNIMethodBlockNode* b = &_head; b != nullptr; b = b->_next) { 2091 if (b->_methods <= m && m < b->_methods + b->_number_of_methods) { 2092 // This is a bit of extra checking, for two reasons. One is 2093 // that contains() deals with pointers that are passed in by 2094 // JNI code, so making sure that the pointer is aligned 2095 // correctly is valuable. The other is that <= and > are 2096 // technically not defined on pointers, so the if guard can 2097 // pass spuriously; no modern compiler is likely to make that 2098 // a problem, though (and if one did, the guard could also 2099 // fail spuriously, which would be bad). 2100 ptrdiff_t idx = m - b->_methods; 2101 if (b->_methods + idx == m) { 2102 return true; 2103 } 2104 } 2105 } 2106 return false; // not found 2107 } 2108 2109 // During class unloading the methods are cleared, which is different 2110 // than freed. 2111 void clear_all_methods() { 2112 for (JNIMethodBlockNode* b = &_head; b != nullptr; b = b->_next) { 2113 for (int i = 0; i< b->_number_of_methods; i++) { 2114 b->_methods[i] = nullptr; 2115 } 2116 } 2117 } 2118 #ifndef PRODUCT 2119 int count_methods() { 2120 // count all allocated methods 2121 int count = 0; 2122 for (JNIMethodBlockNode* b = &_head; b != nullptr; b = b->_next) { 2123 for (int i = 0; i< b->_number_of_methods; i++) { 2124 if (b->_methods[i] != _free_method) count++; 2125 } 2126 } 2127 return count; 2128 } 2129 #endif // PRODUCT 2130 }; 2131 2132 // Something that can't be mistaken for an address or a markWord 2133 Method* const JNIMethodBlock::_free_method = (Method*)55; 2134 2135 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(nullptr) { 2136 _number_of_methods = MAX2(num_methods, min_block_size); 2137 _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal); 2138 for (int i = 0; i < _number_of_methods; i++) { 2139 _methods[i] = JNIMethodBlock::_free_method; 2140 } 2141 } 2142 2143 void Method::ensure_jmethod_ids(ClassLoaderData* cld, int capacity) { 2144 // Have to add jmethod_ids() to class loader data thread-safely. 2145 // Also have to add the method to the list safely, which the lock 2146 // protects as well. 2147 MutexLocker ml(JmethodIdCreation_lock, Mutex::_no_safepoint_check_flag); 2148 if (cld->jmethod_ids() == nullptr) { 2149 cld->set_jmethod_ids(new JNIMethodBlock(capacity)); 2150 } else { 2151 cld->jmethod_ids()->ensure_methods(capacity); 2152 } 2153 } 2154 2155 // Add a method id to the jmethod_ids 2156 jmethodID Method::make_jmethod_id(ClassLoaderData* cld, Method* m) { 2157 // Have to add jmethod_ids() to class loader data thread-safely. 2158 // Also have to add the method to the list safely, which the lock 2159 // protects as well. 2160 assert(JmethodIdCreation_lock->owned_by_self(), "sanity check"); 2161 2162 ResourceMark rm; 2163 log_debug(jmethod)("Creating jmethodID for Method %s", m->external_name()); 2164 if (cld->jmethod_ids() == nullptr) { 2165 cld->set_jmethod_ids(new JNIMethodBlock()); 2166 } 2167 // jmethodID is a pointer to Method* 2168 return (jmethodID)cld->jmethod_ids()->add_method(m); 2169 } 2170 2171 jmethodID Method::jmethod_id() { 2172 methodHandle mh(Thread::current(), this); 2173 return method_holder()->get_jmethod_id(mh); 2174 } 2175 2176 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) { 2177 // Can't assert the method_holder is the same because the new method has the 2178 // scratch method holder. 2179 assert(resolve_jmethod_id(jmid)->method_holder()->class_loader() 2180 == new_method->method_holder()->class_loader() || 2181 new_method->method_holder()->class_loader() == nullptr, // allow Unsafe substitution 2182 "changing to a different class loader"); 2183 // Just change the method in place, jmethodID pointer doesn't change. 2184 *((Method**)jmid) = new_method; 2185 } 2186 2187 bool Method::is_method_id(jmethodID mid) { 2188 Method* m = resolve_jmethod_id(mid); 2189 assert(m != nullptr, "should be called with non-null method"); 2190 InstanceKlass* ik = m->method_holder(); 2191 ClassLoaderData* cld = ik->class_loader_data(); 2192 if (cld->jmethod_ids() == nullptr) return false; 2193 return (cld->jmethod_ids()->contains((Method**)mid)); 2194 } 2195 2196 Method* Method::checked_resolve_jmethod_id(jmethodID mid) { 2197 if (mid == nullptr) return nullptr; 2198 Method* o = resolve_jmethod_id(mid); 2199 if (o == nullptr || o == JNIMethodBlock::_free_method) { 2200 return nullptr; 2201 } 2202 // Method should otherwise be valid. Assert for testing. 2203 assert(is_valid_method(o), "should be valid jmethodid"); 2204 // If the method's class holder object is unreferenced, but not yet marked as 2205 // unloaded, we need to return null here too because after a safepoint, its memory 2206 // will be reclaimed. 2207 return o->method_holder()->is_loader_alive() ? o : nullptr; 2208 }; 2209 2210 void Method::set_on_stack(const bool value) { 2211 // Set both the method itself and its constant pool. The constant pool 2212 // on stack means some method referring to it is also on the stack. 2213 constants()->set_on_stack(value); 2214 2215 bool already_set = on_stack_flag(); 2216 set_on_stack_flag(value); 2217 if (value && !already_set) { 2218 MetadataOnStackMark::record(this); 2219 } 2220 } 2221 2222 void Method::record_gc_epoch() { 2223 // If any method is on the stack in continuations, none of them can be reclaimed, 2224 // so save the marking cycle to check for the whole class in the cpCache. 2225 // The cpCache is writeable. 2226 constants()->cache()->record_gc_epoch(); 2227 } 2228 2229 // Called when the class loader is unloaded to make all methods weak. 2230 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) { 2231 loader_data->jmethod_ids()->clear_all_methods(); 2232 } 2233 2234 void Method::clear_jmethod_id() { 2235 // Being at a safepoint prevents racing against other class redefinitions 2236 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); 2237 // The jmethodID is not stored in the Method instance, we need to look it up first 2238 jmethodID methodid = find_jmethod_id_or_null(); 2239 // We need to make sure that jmethodID actually resolves to this method 2240 // - multiple redefined versions may share jmethodID slots and if a method 2241 // has already been rewired to a newer version we could be removing reference 2242 // to a still existing method instance 2243 if (methodid != nullptr && *((Method**)methodid) == this) { 2244 *((Method**)methodid) = nullptr; 2245 } 2246 } 2247 2248 bool Method::has_method_vptr(const void* ptr) { 2249 Method m; 2250 // This assumes that the vtbl pointer is the first word of a C++ object. 2251 return dereference_vptr(&m) == dereference_vptr(ptr); 2252 } 2253 2254 // Check that this pointer is valid by checking that the vtbl pointer matches 2255 bool Method::is_valid_method(const Method* m) { 2256 if (m == nullptr) { 2257 return false; 2258 } else if ((intptr_t(m) & (wordSize-1)) != 0) { 2259 // Quick sanity check on pointer. 2260 return false; 2261 } else if (!os::is_readable_range(m, m + 1)) { 2262 return false; 2263 } else if (m->is_shared()) { 2264 return CppVtables::is_valid_shared_method(m); 2265 } else if (Metaspace::contains_non_shared(m)) { 2266 return has_method_vptr((const void*)m); 2267 } else { 2268 return false; 2269 } 2270 } 2271 2272 #ifndef PRODUCT 2273 void Method::print_jmethod_ids_count(const ClassLoaderData* loader_data, outputStream* out) { 2274 out->print("%d", loader_data->jmethod_ids()->count_methods()); 2275 } 2276 #endif // PRODUCT 2277 2278 2279 // Printing 2280 2281 #ifndef PRODUCT 2282 2283 void Method::print_on(outputStream* st) const { 2284 ResourceMark rm; 2285 assert(is_method(), "must be method"); 2286 st->print_cr("%s", internal_name()); 2287 st->print_cr(" - this oop: " PTR_FORMAT, p2i(this)); 2288 st->print (" - method holder: "); method_holder()->print_value_on(st); st->cr(); 2289 st->print (" - constants: " PTR_FORMAT " ", p2i(constants())); 2290 constants()->print_value_on(st); st->cr(); 2291 st->print (" - access: 0x%x ", access_flags().as_int()); access_flags().print_on(st); st->cr(); 2292 st->print (" - flags: 0x%x ", _flags.as_int()); _flags.print_on(st); st->cr(); 2293 st->print (" - name: "); name()->print_value_on(st); st->cr(); 2294 st->print (" - signature: "); signature()->print_value_on(st); st->cr(); 2295 st->print_cr(" - max stack: %d", max_stack()); 2296 st->print_cr(" - max locals: %d", max_locals()); 2297 st->print_cr(" - size of params: %d", size_of_parameters()); 2298 st->print_cr(" - method size: %d", method_size()); 2299 if (intrinsic_id() != vmIntrinsics::_none) 2300 st->print_cr(" - intrinsic id: %d %s", vmIntrinsics::as_int(intrinsic_id()), vmIntrinsics::name_at(intrinsic_id())); 2301 if (highest_comp_level() != CompLevel_none) 2302 st->print_cr(" - highest level: %d", highest_comp_level()); 2303 st->print_cr(" - vtable index: %d", _vtable_index); 2304 st->print_cr(" - i2i entry: " PTR_FORMAT, p2i(interpreter_entry())); 2305 st->print( " - adapters: "); 2306 AdapterHandlerEntry* a = ((Method*)this)->adapter(); 2307 if (a == nullptr) 2308 st->print_cr(PTR_FORMAT, p2i(a)); 2309 else 2310 a->print_adapter_on(st); 2311 st->print_cr(" - compiled entry " PTR_FORMAT, p2i(from_compiled_entry())); 2312 st->print_cr(" - code size: %d", code_size()); 2313 if (code_size() != 0) { 2314 st->print_cr(" - code start: " PTR_FORMAT, p2i(code_base())); 2315 st->print_cr(" - code end (excl): " PTR_FORMAT, p2i(code_base() + code_size())); 2316 } 2317 if (method_data() != nullptr) { 2318 st->print_cr(" - method data: " PTR_FORMAT, p2i(method_data())); 2319 } 2320 st->print_cr(" - checked ex length: %d", checked_exceptions_length()); 2321 if (checked_exceptions_length() > 0) { 2322 CheckedExceptionElement* table = checked_exceptions_start(); 2323 st->print_cr(" - checked ex start: " PTR_FORMAT, p2i(table)); 2324 if (Verbose) { 2325 for (int i = 0; i < checked_exceptions_length(); i++) { 2326 st->print_cr(" - throws %s", constants()->printable_name_at(table[i].class_cp_index)); 2327 } 2328 } 2329 } 2330 if (has_linenumber_table()) { 2331 u_char* table = compressed_linenumber_table(); 2332 st->print_cr(" - linenumber start: " PTR_FORMAT, p2i(table)); 2333 if (Verbose) { 2334 CompressedLineNumberReadStream stream(table); 2335 while (stream.read_pair()) { 2336 st->print_cr(" - line %d: %d", stream.line(), stream.bci()); 2337 } 2338 } 2339 } 2340 st->print_cr(" - localvar length: %d", localvariable_table_length()); 2341 if (localvariable_table_length() > 0) { 2342 LocalVariableTableElement* table = localvariable_table_start(); 2343 st->print_cr(" - localvar start: " PTR_FORMAT, p2i(table)); 2344 if (Verbose) { 2345 for (int i = 0; i < localvariable_table_length(); i++) { 2346 int bci = table[i].start_bci; 2347 int len = table[i].length; 2348 const char* name = constants()->printable_name_at(table[i].name_cp_index); 2349 const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index); 2350 int slot = table[i].slot; 2351 st->print_cr(" - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot); 2352 } 2353 } 2354 } 2355 if (code() != nullptr) { 2356 st->print (" - compiled code: "); 2357 code()->print_value_on(st); 2358 } 2359 if (is_native()) { 2360 st->print_cr(" - native function: " PTR_FORMAT, p2i(native_function())); 2361 st->print_cr(" - signature handler: " PTR_FORMAT, p2i(signature_handler())); 2362 } 2363 } 2364 2365 void Method::print_linkage_flags(outputStream* st) { 2366 access_flags().print_on(st); 2367 if (is_default_method()) { 2368 st->print("default "); 2369 } 2370 if (is_overpass()) { 2371 st->print("overpass "); 2372 } 2373 } 2374 #endif //PRODUCT 2375 2376 void Method::print_value_on(outputStream* st) const { 2377 assert(is_method(), "must be method"); 2378 st->print("%s", internal_name()); 2379 print_address_on(st); 2380 st->print(" "); 2381 name()->print_value_on(st); 2382 st->print(" "); 2383 signature()->print_value_on(st); 2384 st->print(" in "); 2385 method_holder()->print_value_on(st); 2386 if (WizardMode) st->print("#%d", _vtable_index); 2387 if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals()); 2388 if (WizardMode && code() != nullptr) st->print(" ((nmethod*)%p)", code()); 2389 } 2390 2391 // Verification 2392 2393 void Method::verify_on(outputStream* st) { 2394 guarantee(is_method(), "object must be method"); 2395 guarantee(constants()->is_constantPool(), "should be constant pool"); 2396 MethodData* md = method_data(); 2397 guarantee(md == nullptr || 2398 md->is_methodData(), "should be method data"); 2399 } --- EOF ---