1 /* 2 * Copyright (c) 1997, 2016, 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/metadataOnStackMark.hpp" 27 #include "classfile/systemDictionary.hpp" 28 #include "code/codeCache.hpp" 29 #include "code/debugInfoRec.hpp" 30 #include "gc/shared/collectedHeap.inline.hpp" 31 #include "gc/shared/gcLocker.hpp" 32 #include "gc/shared/generation.hpp" 33 #include "interpreter/bytecodeStream.hpp" 34 #include "interpreter/bytecodeTracer.hpp" 35 #include "interpreter/bytecodes.hpp" 36 #include "interpreter/interpreter.hpp" 37 #include "interpreter/oopMapCache.hpp" 38 #include "memory/heapInspection.hpp" 39 #include "memory/metadataFactory.hpp" 40 #include "memory/metaspaceShared.hpp" 41 #include "memory/oopFactory.hpp" 42 #include "memory/resourceArea.hpp" 43 #include "oops/constMethod.hpp" 44 #include "oops/method.hpp" 45 #include "oops/methodData.hpp" 46 #include "oops/objArrayOop.inline.hpp" 47 #include "oops/oop.inline.hpp" 48 #include "oops/symbol.hpp" 49 #include "prims/jvmtiExport.hpp" 50 #include "prims/methodHandles.hpp" 51 #include "prims/nativeLookup.hpp" 52 #include "runtime/arguments.hpp" 53 #include "runtime/compilationPolicy.hpp" 54 #include "runtime/frame.inline.hpp" 55 #include "runtime/handles.inline.hpp" 56 #include "runtime/init.hpp" 57 #include "runtime/orderAccess.inline.hpp" 58 #include "runtime/relocator.hpp" 59 #include "runtime/sharedRuntime.hpp" 60 #include "runtime/signature.hpp" 61 #include "utilities/quickSort.hpp" 62 #include "utilities/xmlstream.hpp" 63 64 // Implementation of Method 65 66 Method* Method::allocate(ClassLoaderData* loader_data, 67 int byte_code_size, 68 AccessFlags access_flags, 69 InlineTableSizes* sizes, 70 ConstMethod::MethodType method_type, 71 TRAPS) { 72 assert(!access_flags.is_native() || byte_code_size == 0, 73 "native methods should not contain byte codes"); 74 ConstMethod* cm = ConstMethod::allocate(loader_data, 75 byte_code_size, 76 sizes, 77 method_type, 78 CHECK_NULL); 79 int size = Method::size(access_flags.is_native()); 80 return new (loader_data, size, false, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags); 81 } 82 83 Method::Method(ConstMethod* xconst, AccessFlags access_flags) { 84 NoSafepointVerifier no_safepoint; 85 set_constMethod(xconst); 86 set_access_flags(access_flags); 87 set_intrinsic_id(vmIntrinsics::_none); 88 set_jfr_towrite(false); 89 set_force_inline(false); 90 set_hidden(false); 91 set_dont_inline(false); 92 set_has_injected_profile(false); 93 set_method_data(NULL); 94 clear_method_counters(); 95 set_vtable_index(Method::garbage_vtable_index); 96 97 // Fix and bury in Method* 98 set_interpreter_entry(NULL); // sets i2i entry and from_int 99 set_adapter_entry(NULL); 100 clear_code(); // from_c/from_i get set to c2i/i2i 101 102 if (access_flags.is_native()) { 103 clear_native_function(); 104 set_signature_handler(NULL); 105 } 106 107 NOT_PRODUCT(set_compiled_invocation_count(0);) 108 } 109 110 // Release Method*. The nmethod will be gone when we get here because 111 // we've walked the code cache. 112 void Method::deallocate_contents(ClassLoaderData* loader_data) { 113 MetadataFactory::free_metadata(loader_data, constMethod()); 114 set_constMethod(NULL); 115 MetadataFactory::free_metadata(loader_data, method_data()); 116 set_method_data(NULL); 117 MetadataFactory::free_metadata(loader_data, method_counters()); 118 clear_method_counters(); 119 // The nmethod will be gone when we get here. 120 if (code() != NULL) _code = NULL; 121 } 122 123 address Method::get_i2c_entry() { 124 assert(adapter() != NULL, "must have"); 125 return adapter()->get_i2c_entry(); 126 } 127 128 address Method::get_c2i_entry() { 129 assert(adapter() != NULL, "must have"); 130 return adapter()->get_c2i_entry(); 131 } 132 133 address Method::get_c2i_unverified_entry() { 134 assert(adapter() != NULL, "must have"); 135 return adapter()->get_c2i_unverified_entry(); 136 } 137 138 char* Method::name_and_sig_as_C_string() const { 139 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature()); 140 } 141 142 char* Method::name_and_sig_as_C_string(char* buf, int size) const { 143 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size); 144 } 145 146 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) { 147 const char* klass_name = klass->external_name(); 148 int klass_name_len = (int)strlen(klass_name); 149 int method_name_len = method_name->utf8_length(); 150 int len = klass_name_len + 1 + method_name_len + signature->utf8_length(); 151 char* dest = NEW_RESOURCE_ARRAY(char, len + 1); 152 strcpy(dest, klass_name); 153 dest[klass_name_len] = '.'; 154 strcpy(&dest[klass_name_len + 1], method_name->as_C_string()); 155 strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string()); 156 dest[len] = 0; 157 return dest; 158 } 159 160 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) { 161 Symbol* klass_name = klass->name(); 162 klass_name->as_klass_external_name(buf, size); 163 int len = (int)strlen(buf); 164 165 if (len < size - 1) { 166 buf[len++] = '.'; 167 168 method_name->as_C_string(&(buf[len]), size - len); 169 len = (int)strlen(buf); 170 171 signature->as_C_string(&(buf[len]), size - len); 172 } 173 174 return buf; 175 } 176 177 int Method::fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS) { 178 // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index) 179 // access exception table 180 ExceptionTable table(mh()); 181 int length = table.length(); 182 // iterate through all entries sequentially 183 constantPoolHandle pool(THREAD, mh->constants()); 184 for (int i = 0; i < length; i ++) { 185 //reacquire the table in case a GC happened 186 ExceptionTable table(mh()); 187 int beg_bci = table.start_pc(i); 188 int end_bci = table.end_pc(i); 189 assert(beg_bci <= end_bci, "inconsistent exception table"); 190 if (beg_bci <= throw_bci && throw_bci < end_bci) { 191 // exception handler bci range covers throw_bci => investigate further 192 int handler_bci = table.handler_pc(i); 193 int klass_index = table.catch_type_index(i); 194 if (klass_index == 0) { 195 return handler_bci; 196 } else if (ex_klass.is_null()) { 197 return handler_bci; 198 } else { 199 // we know the exception class => get the constraint class 200 // this may require loading of the constraint class; if verification 201 // fails or some other exception occurs, return handler_bci 202 Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci)); 203 KlassHandle klass = KlassHandle(THREAD, k); 204 assert(klass.not_null(), "klass not loaded"); 205 if (ex_klass->is_subtype_of(klass())) { 206 return handler_bci; 207 } 208 } 209 } 210 } 211 212 return -1; 213 } 214 215 void Method::mask_for(int bci, InterpreterOopMap* mask) { 216 217 Thread* myThread = Thread::current(); 218 methodHandle h_this(myThread, this); 219 #if defined(ASSERT) && !INCLUDE_JVMCI 220 bool has_capability = myThread->is_VM_thread() || 221 myThread->is_ConcurrentGC_thread() || 222 myThread->is_GC_task_thread(); 223 224 if (!has_capability) { 225 if (!VerifyStack && !VerifyLastFrame) { 226 // verify stack calls this outside VM thread 227 warning("oopmap should only be accessed by the " 228 "VM, GC task or CMS threads (or during debugging)"); 229 InterpreterOopMap local_mask; 230 method_holder()->mask_for(h_this, bci, &local_mask); 231 local_mask.print(); 232 } 233 } 234 #endif 235 method_holder()->mask_for(h_this, bci, mask); 236 return; 237 } 238 239 240 int Method::bci_from(address bcp) const { 241 if (is_native() && bcp == 0) { 242 return 0; 243 } 244 #ifdef ASSERT 245 { 246 ResourceMark rm; 247 assert(is_native() && bcp == code_base() || contains(bcp) || is_error_reported(), 248 "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s", 249 p2i(bcp), name_and_sig_as_C_string()); 250 } 251 #endif 252 return bcp - code_base(); 253 } 254 255 256 int Method::validate_bci(int bci) const { 257 return (bci == 0 || bci < code_size()) ? bci : -1; 258 } 259 260 // Return bci if it appears to be a valid bcp 261 // Return -1 otherwise. 262 // Used by profiling code, when invalid data is a possibility. 263 // The caller is responsible for validating the Method* itself. 264 int Method::validate_bci_from_bcp(address bcp) const { 265 // keep bci as -1 if not a valid bci 266 int bci = -1; 267 if (bcp == 0 || bcp == code_base()) { 268 // code_size() may return 0 and we allow 0 here 269 // the method may be native 270 bci = 0; 271 } else if (contains(bcp)) { 272 bci = bcp - code_base(); 273 } 274 // Assert that if we have dodged any asserts, bci is negative. 275 assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0"); 276 return bci; 277 } 278 279 address Method::bcp_from(int bci) const { 280 assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()), 281 "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native"); 282 address bcp = code_base() + bci; 283 assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method"); 284 return bcp; 285 } 286 287 address Method::bcp_from(address bcp) const { 288 if (is_native() && bcp == NULL) { 289 return code_base(); 290 } else { 291 return bcp; 292 } 293 } 294 295 int Method::size(bool is_native) { 296 // If native, then include pointers for native_function and signature_handler 297 int extra_bytes = (is_native) ? 2*sizeof(address*) : 0; 298 int extra_words = align_size_up(extra_bytes, BytesPerWord) / BytesPerWord; 299 return align_metadata_size(header_size() + extra_words); 300 } 301 302 303 Symbol* Method::klass_name() const { 304 return method_holder()->name(); 305 } 306 307 308 // Attempt to return method oop to original state. Clear any pointers 309 // (to objects outside the shared spaces). We won't be able to predict 310 // where they should point in a new JVM. Further initialize some 311 // entries now in order allow them to be write protected later. 312 313 void Method::remove_unshareable_info() { 314 unlink_method(); 315 } 316 317 void Method::set_vtable_index(int index) { 318 if (is_shared() && !MetaspaceShared::remapped_readwrite()) { 319 // At runtime initialize_vtable is rerun as part of link_class_impl() 320 // for a shared class loaded by the non-boot loader to obtain the loader 321 // constraints based on the runtime classloaders' context. 322 return; // don't write into the shared class 323 } else { 324 _vtable_index = index; 325 } 326 } 327 328 void Method::set_itable_index(int index) { 329 if (is_shared() && !MetaspaceShared::remapped_readwrite()) { 330 // At runtime initialize_itable is rerun as part of link_class_impl() 331 // for a shared class loaded by the non-boot loader to obtain the loader 332 // constraints based on the runtime classloaders' context. The dumptime 333 // itable index should be the same as the runtime index. 334 assert(_vtable_index == itable_index_max - index, 335 "archived itable index is different from runtime index"); 336 return; // don’t write into the shared class 337 } else { 338 _vtable_index = itable_index_max - index; 339 } 340 assert(valid_itable_index(), ""); 341 } 342 343 344 345 bool Method::was_executed_more_than(int n) { 346 // Invocation counter is reset when the Method* is compiled. 347 // If the method has compiled code we therefore assume it has 348 // be excuted more than n times. 349 if (is_accessor() || is_empty_method() || (code() != NULL)) { 350 // interpreter doesn't bump invocation counter of trivial methods 351 // compiler does not bump invocation counter of compiled methods 352 return true; 353 } 354 else if ((method_counters() != NULL && 355 method_counters()->invocation_counter()->carry()) || 356 (method_data() != NULL && 357 method_data()->invocation_counter()->carry())) { 358 // The carry bit is set when the counter overflows and causes 359 // a compilation to occur. We don't know how many times 360 // the counter has been reset, so we simply assume it has 361 // been executed more than n times. 362 return true; 363 } else { 364 return invocation_count() > n; 365 } 366 } 367 368 void Method::print_invocation_count() { 369 if (is_static()) tty->print("static "); 370 if (is_final()) tty->print("final "); 371 if (is_synchronized()) tty->print("synchronized "); 372 if (is_native()) tty->print("native "); 373 tty->print("%s::", method_holder()->external_name()); 374 name()->print_symbol_on(tty); 375 signature()->print_symbol_on(tty); 376 377 if (WizardMode) { 378 // dump the size of the byte codes 379 tty->print(" {%d}", code_size()); 380 } 381 tty->cr(); 382 383 tty->print_cr (" interpreter_invocation_count: %8d ", interpreter_invocation_count()); 384 tty->print_cr (" invocation_counter: %8d ", invocation_count()); 385 tty->print_cr (" backedge_counter: %8d ", backedge_count()); 386 #ifndef PRODUCT 387 if (CountCompiledCalls) { 388 tty->print_cr (" compiled_invocation_count: %8d ", compiled_invocation_count()); 389 } 390 #endif 391 } 392 393 // Build a MethodData* object to hold information about this method 394 // collected in the interpreter. 395 void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) { 396 // Do not profile the method if metaspace has hit an OOM previously 397 // allocating profiling data. Callers clear pending exception so don't 398 // add one here. 399 if (ClassLoaderDataGraph::has_metaspace_oom()) { 400 return; 401 } 402 403 // Grab a lock here to prevent multiple 404 // MethodData*s from being created. 405 MutexLocker ml(MethodData_lock, THREAD); 406 if (method->method_data() == NULL) { 407 ClassLoaderData* loader_data = method->method_holder()->class_loader_data(); 408 MethodData* method_data = MethodData::allocate(loader_data, method, THREAD); 409 if (HAS_PENDING_EXCEPTION) { 410 CompileBroker::log_metaspace_failure(); 411 ClassLoaderDataGraph::set_metaspace_oom(true); 412 return; // return the exception (which is cleared) 413 } 414 415 method->set_method_data(method_data); 416 if (PrintMethodData && (Verbose || WizardMode)) { 417 ResourceMark rm(THREAD); 418 tty->print("build_interpreter_method_data for "); 419 method->print_name(tty); 420 tty->cr(); 421 // At the end of the run, the MDO, full of data, will be dumped. 422 } 423 } 424 } 425 426 MethodCounters* Method::build_method_counters(Method* m, TRAPS) { 427 // Do not profile the method if metaspace has hit an OOM previously 428 if (ClassLoaderDataGraph::has_metaspace_oom()) { 429 return NULL; 430 } 431 432 methodHandle mh(m); 433 MethodCounters* counters = MethodCounters::allocate(mh, THREAD); 434 if (HAS_PENDING_EXCEPTION) { 435 CompileBroker::log_metaspace_failure(); 436 ClassLoaderDataGraph::set_metaspace_oom(true); 437 return NULL; // return the exception (which is cleared) 438 } 439 if (!mh->init_method_counters(counters)) { 440 MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters); 441 } 442 443 if (LogTouchedMethods) { 444 mh->log_touched(CHECK_NULL); 445 } 446 447 return mh->method_counters(); 448 } 449 450 void Method::cleanup_inline_caches() { 451 // The current system doesn't use inline caches in the interpreter 452 // => nothing to do (keep this method around for future use) 453 } 454 455 456 int Method::extra_stack_words() { 457 // not an inline function, to avoid a header dependency on Interpreter 458 return extra_stack_entries() * Interpreter::stackElementSize; 459 } 460 461 462 void Method::compute_size_of_parameters(Thread *thread) { 463 ArgumentSizeComputer asc(signature()); 464 set_size_of_parameters(asc.size() + (is_static() ? 0 : 1)); 465 } 466 467 BasicType Method::result_type() const { 468 ResultTypeFinder rtf(signature()); 469 return rtf.type(); 470 } 471 472 473 bool Method::is_empty_method() const { 474 return code_size() == 1 475 && *code_base() == Bytecodes::_return; 476 } 477 478 479 bool Method::is_vanilla_constructor() const { 480 // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method 481 // which only calls the superclass vanilla constructor and possibly does stores of 482 // zero constants to local fields: 483 // 484 // aload_0 485 // invokespecial 486 // indexbyte1 487 // indexbyte2 488 // 489 // followed by an (optional) sequence of: 490 // 491 // aload_0 492 // aconst_null / iconst_0 / fconst_0 / dconst_0 493 // putfield 494 // indexbyte1 495 // indexbyte2 496 // 497 // followed by: 498 // 499 // return 500 501 assert(name() == vmSymbols::object_initializer_name(), "Should only be called for default constructors"); 502 assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors"); 503 int size = code_size(); 504 // Check if size match 505 if (size == 0 || size % 5 != 0) return false; 506 address cb = code_base(); 507 int last = size - 1; 508 if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) { 509 // Does not call superclass default constructor 510 return false; 511 } 512 // Check optional sequence 513 for (int i = 4; i < last; i += 5) { 514 if (cb[i] != Bytecodes::_aload_0) return false; 515 if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false; 516 if (cb[i+2] != Bytecodes::_putfield) return false; 517 } 518 return true; 519 } 520 521 522 bool Method::compute_has_loops_flag() { 523 BytecodeStream bcs(this); 524 Bytecodes::Code bc; 525 526 while ((bc = bcs.next()) >= 0) { 527 switch( bc ) { 528 case Bytecodes::_ifeq: 529 case Bytecodes::_ifnull: 530 case Bytecodes::_iflt: 531 case Bytecodes::_ifle: 532 case Bytecodes::_ifne: 533 case Bytecodes::_ifnonnull: 534 case Bytecodes::_ifgt: 535 case Bytecodes::_ifge: 536 case Bytecodes::_if_icmpeq: 537 case Bytecodes::_if_icmpne: 538 case Bytecodes::_if_icmplt: 539 case Bytecodes::_if_icmpgt: 540 case Bytecodes::_if_icmple: 541 case Bytecodes::_if_icmpge: 542 case Bytecodes::_if_acmpeq: 543 case Bytecodes::_if_acmpne: 544 case Bytecodes::_goto: 545 case Bytecodes::_jsr: 546 if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops(); 547 break; 548 549 case Bytecodes::_goto_w: 550 case Bytecodes::_jsr_w: 551 if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops(); 552 break; 553 } 554 } 555 _access_flags.set_loops_flag_init(); 556 return _access_flags.has_loops(); 557 } 558 559 bool Method::is_final_method(AccessFlags class_access_flags) const { 560 // or "does_not_require_vtable_entry" 561 // default method or overpass can occur, is not final (reuses vtable entry) 562 // private methods in classes get vtable entries for backward class compatibility. 563 if (is_overpass() || is_default_method()) return false; 564 return is_final() || class_access_flags.is_final(); 565 } 566 567 bool Method::is_final_method() const { 568 return is_final_method(method_holder()->access_flags()); 569 } 570 571 bool Method::is_default_method() const { 572 if (method_holder() != NULL && 573 method_holder()->is_interface() && 574 !is_abstract() && !is_private()) { 575 return true; 576 } else { 577 return false; 578 } 579 } 580 581 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const { 582 if (is_final_method(class_access_flags)) return true; 583 #ifdef ASSERT 584 ResourceMark rm; 585 bool is_nonv = (vtable_index() == nonvirtual_vtable_index); 586 if (class_access_flags.is_interface()) { 587 assert(is_nonv == is_static() || is_nonv == is_private(), 588 "nonvirtual unexpected for non-static, non-private: %s", 589 name_and_sig_as_C_string()); 590 } 591 #endif 592 assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question"); 593 return vtable_index() == nonvirtual_vtable_index; 594 } 595 596 bool Method::can_be_statically_bound() const { 597 return can_be_statically_bound(method_holder()->access_flags()); 598 } 599 600 bool Method::is_accessor() const { 601 return is_getter() || is_setter(); 602 } 603 604 bool Method::is_getter() const { 605 if (code_size() != 5) return false; 606 if (size_of_parameters() != 1) return false; 607 if (java_code_at(0) != Bytecodes::_aload_0) return false; 608 if (java_code_at(1) != Bytecodes::_getfield) return false; 609 switch (java_code_at(4)) { 610 case Bytecodes::_ireturn: 611 case Bytecodes::_lreturn: 612 case Bytecodes::_freturn: 613 case Bytecodes::_dreturn: 614 case Bytecodes::_areturn: 615 break; 616 default: 617 return false; 618 } 619 return true; 620 } 621 622 bool Method::is_setter() const { 623 if (code_size() != 6) return false; 624 if (java_code_at(0) != Bytecodes::_aload_0) return false; 625 switch (java_code_at(1)) { 626 case Bytecodes::_iload_1: 627 case Bytecodes::_aload_1: 628 case Bytecodes::_fload_1: 629 if (size_of_parameters() != 2) return false; 630 break; 631 case Bytecodes::_dload_1: 632 case Bytecodes::_lload_1: 633 if (size_of_parameters() != 3) return false; 634 break; 635 default: 636 return false; 637 } 638 if (java_code_at(2) != Bytecodes::_putfield) return false; 639 if (java_code_at(5) != Bytecodes::_return) return false; 640 return true; 641 } 642 643 bool Method::is_constant_getter() const { 644 int last_index = code_size() - 1; 645 // Check if the first 1-3 bytecodes are a constant push 646 // and the last bytecode is a return. 647 return (2 <= code_size() && code_size() <= 4 && 648 Bytecodes::is_const(java_code_at(0)) && 649 Bytecodes::length_for(java_code_at(0)) == last_index && 650 Bytecodes::is_return(java_code_at(last_index))); 651 } 652 653 bool Method::is_initializer() const { 654 return is_object_initializer() || is_static_initializer(); 655 } 656 657 bool Method::has_valid_initializer_flags() const { 658 return (is_static() || 659 method_holder()->major_version() < 51); 660 } 661 662 bool Method::is_static_initializer() const { 663 // For classfiles version 51 or greater, ensure that the clinit method is 664 // static. Non-static methods with the name "<clinit>" are not static 665 // initializers. (older classfiles exempted for backward compatibility) 666 return name() == vmSymbols::class_initializer_name() && 667 has_valid_initializer_flags(); 668 } 669 670 bool Method::is_object_initializer() const { 671 return name() == vmSymbols::object_initializer_name(); 672 } 673 674 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) { 675 int length = method->checked_exceptions_length(); 676 if (length == 0) { // common case 677 return objArrayHandle(THREAD, Universe::the_empty_class_klass_array()); 678 } else { 679 methodHandle h_this(THREAD, method); 680 objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle())); 681 objArrayHandle mirrors (THREAD, m_oop); 682 for (int i = 0; i < length; i++) { 683 CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe 684 Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle())); 685 assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class"); 686 mirrors->obj_at_put(i, k->java_mirror()); 687 } 688 return mirrors; 689 } 690 }; 691 692 693 int Method::line_number_from_bci(int bci) const { 694 if (bci == SynchronizationEntryBCI) bci = 0; 695 assert(bci == 0 || 0 <= bci && bci < code_size(), "illegal bci"); 696 int best_bci = 0; 697 int best_line = -1; 698 699 if (has_linenumber_table()) { 700 // The line numbers are a short array of 2-tuples [start_pc, line_number]. 701 // Not necessarily sorted and not necessarily one-to-one. 702 CompressedLineNumberReadStream stream(compressed_linenumber_table()); 703 while (stream.read_pair()) { 704 if (stream.bci() == bci) { 705 // perfect match 706 return stream.line(); 707 } else { 708 // update best_bci/line 709 if (stream.bci() < bci && stream.bci() >= best_bci) { 710 best_bci = stream.bci(); 711 best_line = stream.line(); 712 } 713 } 714 } 715 } 716 return best_line; 717 } 718 719 720 bool Method::is_klass_loaded_by_klass_index(int klass_index) const { 721 if( constants()->tag_at(klass_index).is_unresolved_klass() ) { 722 Thread *thread = Thread::current(); 723 Symbol* klass_name = constants()->klass_name_at(klass_index); 724 Handle loader(thread, method_holder()->class_loader()); 725 Handle prot (thread, method_holder()->protection_domain()); 726 return SystemDictionary::find(klass_name, loader, prot, thread) != NULL; 727 } else { 728 return true; 729 } 730 } 731 732 733 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const { 734 int klass_index = constants()->klass_ref_index_at(refinfo_index); 735 if (must_be_resolved) { 736 // Make sure klass is resolved in constantpool. 737 if (constants()->tag_at(klass_index).is_unresolved_klass()) return false; 738 } 739 return is_klass_loaded_by_klass_index(klass_index); 740 } 741 742 743 void Method::set_native_function(address function, bool post_event_flag) { 744 assert(function != NULL, "use clear_native_function to unregister natives"); 745 assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), ""); 746 address* native_function = native_function_addr(); 747 748 // We can see racers trying to place the same native function into place. Once 749 // is plenty. 750 address current = *native_function; 751 if (current == function) return; 752 if (post_event_flag && JvmtiExport::should_post_native_method_bind() && 753 function != NULL) { 754 // native_method_throw_unsatisfied_link_error_entry() should only 755 // be passed when post_event_flag is false. 756 assert(function != 757 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), 758 "post_event_flag mis-match"); 759 760 // post the bind event, and possible change the bind function 761 JvmtiExport::post_native_method_bind(this, &function); 762 } 763 *native_function = function; 764 // This function can be called more than once. We must make sure that we always 765 // use the latest registered method -> check if a stub already has been generated. 766 // If so, we have to make it not_entrant. 767 CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates 768 if (nm != NULL) { 769 nm->make_not_entrant(); 770 } 771 } 772 773 774 bool Method::has_native_function() const { 775 if (is_method_handle_intrinsic()) 776 return false; // special-cased in SharedRuntime::generate_native_wrapper 777 address func = native_function(); 778 return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry()); 779 } 780 781 782 void Method::clear_native_function() { 783 // Note: is_method_handle_intrinsic() is allowed here. 784 set_native_function( 785 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), 786 !native_bind_event_is_interesting); 787 clear_code(); 788 } 789 790 address Method::critical_native_function() { 791 methodHandle mh(this); 792 return NativeLookup::lookup_critical_entry(mh); 793 } 794 795 796 void Method::set_signature_handler(address handler) { 797 address* signature_handler = signature_handler_addr(); 798 *signature_handler = handler; 799 } 800 801 802 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) { 803 if (PrintCompilation && report) { 804 ttyLocker ttyl; 805 tty->print("made not %scompilable on ", is_osr ? "OSR " : ""); 806 if (comp_level == CompLevel_all) { 807 tty->print("all levels "); 808 } else { 809 tty->print("levels "); 810 for (int i = (int)CompLevel_none; i <= comp_level; i++) { 811 tty->print("%d ", i); 812 } 813 } 814 this->print_short_name(tty); 815 int size = this->code_size(); 816 if (size > 0) { 817 tty->print(" (%d bytes)", size); 818 } 819 if (reason != NULL) { 820 tty->print(" %s", reason); 821 } 822 tty->cr(); 823 } 824 if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) { 825 ttyLocker ttyl; 826 xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'", 827 os::current_thread_id(), is_osr, comp_level); 828 if (reason != NULL) { 829 xtty->print(" reason=\'%s\'", reason); 830 } 831 xtty->method(this); 832 xtty->stamp(); 833 xtty->end_elem(); 834 } 835 } 836 837 bool Method::is_always_compilable() const { 838 // Generated adapters must be compiled 839 if (is_method_handle_intrinsic() && is_synthetic()) { 840 assert(!is_not_c1_compilable(), "sanity check"); 841 assert(!is_not_c2_compilable(), "sanity check"); 842 return true; 843 } 844 845 return false; 846 } 847 848 bool Method::is_not_compilable(int comp_level) const { 849 if (number_of_breakpoints() > 0) 850 return true; 851 if (is_always_compilable()) 852 return false; 853 if (comp_level == CompLevel_any) 854 return is_not_c1_compilable() || is_not_c2_compilable(); 855 if (is_c1_compile(comp_level)) 856 return is_not_c1_compilable(); 857 if (is_c2_compile(comp_level)) 858 return is_not_c2_compilable(); 859 return false; 860 } 861 862 // call this when compiler finds that this method is not compilable 863 void Method::set_not_compilable(int comp_level, bool report, const char* reason) { 864 if (is_always_compilable()) { 865 // Don't mark a method which should be always compilable 866 return; 867 } 868 print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason); 869 if (comp_level == CompLevel_all) { 870 set_not_c1_compilable(); 871 set_not_c2_compilable(); 872 } else { 873 if (is_c1_compile(comp_level)) 874 set_not_c1_compilable(); 875 if (is_c2_compile(comp_level)) 876 set_not_c2_compilable(); 877 } 878 CompilationPolicy::policy()->disable_compilation(this); 879 assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check"); 880 } 881 882 bool Method::is_not_osr_compilable(int comp_level) const { 883 if (is_not_compilable(comp_level)) 884 return true; 885 if (comp_level == CompLevel_any) 886 return is_not_c1_osr_compilable() || is_not_c2_osr_compilable(); 887 if (is_c1_compile(comp_level)) 888 return is_not_c1_osr_compilable(); 889 if (is_c2_compile(comp_level)) 890 return is_not_c2_osr_compilable(); 891 return false; 892 } 893 894 void Method::set_not_osr_compilable(int comp_level, bool report, const char* reason) { 895 print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason); 896 if (comp_level == CompLevel_all) { 897 set_not_c1_osr_compilable(); 898 set_not_c2_osr_compilable(); 899 } else { 900 if (is_c1_compile(comp_level)) 901 set_not_c1_osr_compilable(); 902 if (is_c2_compile(comp_level)) 903 set_not_c2_osr_compilable(); 904 } 905 CompilationPolicy::policy()->disable_compilation(this); 906 assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check"); 907 } 908 909 // Revert to using the interpreter and clear out the nmethod 910 void Method::clear_code() { 911 912 // this may be NULL if c2i adapters have not been made yet 913 // Only should happen at allocate time. 914 if (adapter() == NULL) { 915 _from_compiled_entry = NULL; 916 } else { 917 _from_compiled_entry = adapter()->get_c2i_entry(); 918 } 919 OrderAccess::storestore(); 920 _from_interpreted_entry = _i2i_entry; 921 OrderAccess::storestore(); 922 _code = NULL; 923 } 924 925 #if INCLUDE_CDS 926 // Called by class data sharing to remove any entry points (which are not shared) 927 void Method::unlink_method() { 928 _code = NULL; 929 930 assert(DumpSharedSpaces, "dump time only"); 931 // Set the values to what they should be at run time. Note that 932 // this Method can no longer be executed during dump time. 933 _i2i_entry = Interpreter::entry_for_cds_method(this); 934 _from_interpreted_entry = _i2i_entry; 935 936 if (is_native()) { 937 *native_function_addr() = NULL; 938 set_signature_handler(NULL); 939 } 940 NOT_PRODUCT(set_compiled_invocation_count(0);) 941 942 CDSAdapterHandlerEntry* cds_adapter = (CDSAdapterHandlerEntry*)adapter(); 943 constMethod()->set_adapter_trampoline(cds_adapter->get_adapter_trampoline()); 944 _from_compiled_entry = cds_adapter->get_c2i_entry_trampoline(); 945 assert(*((int*)_from_compiled_entry) == 0, "must be NULL during dump time, to be initialized at run time"); 946 947 948 // In case of DumpSharedSpaces, _method_data should always be NULL. 949 assert(_method_data == NULL, "unexpected method data?"); 950 951 set_method_data(NULL); 952 clear_method_counters(); 953 } 954 #endif 955 956 // Called when the method_holder is getting linked. Setup entrypoints so the method 957 // is ready to be called from interpreter, compiler, and vtables. 958 void Method::link_method(const methodHandle& h_method, TRAPS) { 959 // If the code cache is full, we may reenter this function for the 960 // leftover methods that weren't linked. 961 if (is_shared()) { 962 if (adapter() != NULL) return; 963 } else { 964 if (_i2i_entry != NULL) return; 965 966 assert(adapter() == NULL, "init'd to NULL" ); 967 } 968 assert( _code == NULL, "nothing compiled yet" ); 969 970 // Setup interpreter entrypoint 971 assert(this == h_method(), "wrong h_method()" ); 972 address entry; 973 974 if (this->is_shared()) { 975 entry = Interpreter::entry_for_cds_method(h_method); 976 } else { 977 entry = Interpreter::entry_for_method(h_method); 978 } 979 assert(entry != NULL, "interpreter entry must be non-null"); 980 if (is_shared()) { 981 assert(entry == _i2i_entry && entry == _from_interpreted_entry, 982 "should be correctly set during dump time"); 983 } else { 984 // Sets both _i2i_entry and _from_interpreted_entry 985 set_interpreter_entry(entry); 986 } 987 988 // Don't overwrite already registered native entries. 989 if (is_native() && !has_native_function()) { 990 set_native_function( 991 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), 992 !native_bind_event_is_interesting); 993 } 994 995 // Setup compiler entrypoint. This is made eagerly, so we do not need 996 // special handling of vtables. An alternative is to make adapters more 997 // lazily by calling make_adapter() from from_compiled_entry() for the 998 // normal calls. For vtable calls life gets more complicated. When a 999 // call-site goes mega-morphic we need adapters in all methods which can be 1000 // called from the vtable. We need adapters on such methods that get loaded 1001 // later. Ditto for mega-morphic itable calls. If this proves to be a 1002 // problem we'll make these lazily later. 1003 (void) make_adapters(h_method, CHECK); 1004 1005 // ONLY USE the h_method now as make_adapter may have blocked 1006 1007 } 1008 1009 address Method::make_adapters(methodHandle mh, TRAPS) { 1010 // Adapters for compiled code are made eagerly here. They are fairly 1011 // small (generally < 100 bytes) and quick to make (and cached and shared) 1012 // so making them eagerly shouldn't be too expensive. 1013 AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh); 1014 if (adapter == NULL ) { 1015 if (!is_init_completed()) { 1016 // Don't throw exceptions during VM initialization because java.lang.* classes 1017 // might not have been initialized, causing problems when constructing the 1018 // Java exception object. 1019 vm_exit_during_initialization("Out of space in CodeCache for adapters"); 1020 } else { 1021 THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters"); 1022 } 1023 } 1024 1025 if (mh->is_shared()) { 1026 assert(mh->adapter() == adapter, "must be"); 1027 assert(mh->_from_compiled_entry != NULL, "must be"); // FIXME, the instructions also not NULL 1028 } else { 1029 mh->set_adapter_entry(adapter); 1030 mh->_from_compiled_entry = adapter->get_c2i_entry(); 1031 } 1032 return adapter->get_c2i_entry(); 1033 } 1034 1035 void Method::restore_unshareable_info(TRAPS) { 1036 // Since restore_unshareable_info can be called more than once for a method, don't 1037 // redo any work. If this field is restored, there is nothing to do. 1038 if (_from_compiled_entry == NULL) { 1039 // restore method's vtable by calling a virtual function 1040 restore_vtable(); 1041 1042 methodHandle mh(THREAD, this); 1043 link_method(mh, CHECK); 1044 } 1045 } 1046 1047 volatile address Method::from_compiled_entry_no_trampoline() const { 1048 nmethod *code = (nmethod *)OrderAccess::load_ptr_acquire(&_code); 1049 if (code) { 1050 return code->verified_entry_point(); 1051 } else { 1052 return adapter()->get_c2i_entry(); 1053 } 1054 } 1055 1056 // The verified_code_entry() must be called when a invoke is resolved 1057 // on this method. 1058 1059 // It returns the compiled code entry point, after asserting not null. 1060 // This function is called after potential safepoints so that nmethod 1061 // or adapter that it points to is still live and valid. 1062 // This function must not hit a safepoint! 1063 address Method::verified_code_entry() { 1064 debug_only(NoSafepointVerifier nsv;) 1065 assert(_from_compiled_entry != NULL, "must be set"); 1066 return _from_compiled_entry; 1067 } 1068 1069 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all 1070 // (could be racing a deopt). 1071 // Not inline to avoid circular ref. 1072 bool Method::check_code() const { 1073 // cached in a register or local. There's a race on the value of the field. 1074 CompiledMethod *code = (CompiledMethod *)OrderAccess::load_ptr_acquire(&_code); 1075 return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method()); 1076 } 1077 1078 // Install compiled code. Instantly it can execute. 1079 void Method::set_code(methodHandle mh, CompiledMethod *code) { 1080 assert( code, "use clear_code to remove code" ); 1081 assert( mh->check_code(), "" ); 1082 1083 guarantee(mh->adapter() != NULL, "Adapter blob must already exist!"); 1084 1085 // These writes must happen in this order, because the interpreter will 1086 // directly jump to from_interpreted_entry which jumps to an i2c adapter 1087 // which jumps to _from_compiled_entry. 1088 mh->_code = code; // Assign before allowing compiled code to exec 1089 1090 int comp_level = code->comp_level(); 1091 // In theory there could be a race here. In practice it is unlikely 1092 // and not worth worrying about. 1093 if (comp_level > mh->highest_comp_level()) { 1094 mh->set_highest_comp_level(comp_level); 1095 } 1096 1097 OrderAccess::storestore(); 1098 #ifdef SHARK 1099 mh->_from_interpreted_entry = code->insts_begin(); 1100 #else //!SHARK 1101 mh->_from_compiled_entry = code->verified_entry_point(); 1102 OrderAccess::storestore(); 1103 // Instantly compiled code can execute. 1104 if (!mh->is_method_handle_intrinsic()) 1105 mh->_from_interpreted_entry = mh->get_i2c_entry(); 1106 #endif //!SHARK 1107 } 1108 1109 1110 bool Method::is_overridden_in(Klass* k) const { 1111 InstanceKlass* ik = InstanceKlass::cast(k); 1112 1113 if (ik->is_interface()) return false; 1114 1115 // If method is an interface, we skip it - except if it 1116 // is a miranda method 1117 if (method_holder()->is_interface()) { 1118 // Check that method is not a miranda method 1119 if (ik->lookup_method(name(), signature()) == NULL) { 1120 // No implementation exist - so miranda method 1121 return false; 1122 } 1123 return true; 1124 } 1125 1126 assert(ik->is_subclass_of(method_holder()), "should be subklass"); 1127 assert(ik->vtable() != NULL, "vtable should exist"); 1128 if (!has_vtable_index()) { 1129 return false; 1130 } else { 1131 Method* vt_m = ik->method_at_vtable(vtable_index()); 1132 return vt_m != this; 1133 } 1134 } 1135 1136 1137 // give advice about whether this Method* should be cached or not 1138 bool Method::should_not_be_cached() const { 1139 if (is_old()) { 1140 // This method has been redefined. It is either EMCP or obsolete 1141 // and we don't want to cache it because that would pin the method 1142 // down and prevent it from being collectible if and when it 1143 // finishes executing. 1144 return true; 1145 } 1146 1147 // caching this method should be just fine 1148 return false; 1149 } 1150 1151 1152 /** 1153 * Returns true if this is one of the specially treated methods for 1154 * security related stack walks (like Reflection.getCallerClass). 1155 */ 1156 bool Method::is_ignored_by_security_stack_walk() const { 1157 if (intrinsic_id() == vmIntrinsics::_invoke) { 1158 // This is Method.invoke() -- ignore it 1159 return true; 1160 } 1161 if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) { 1162 // This is an auxilary frame -- ignore it 1163 return true; 1164 } 1165 if (is_method_handle_intrinsic() || is_compiled_lambda_form()) { 1166 // This is an internal adapter frame for method handles -- ignore it 1167 return true; 1168 } 1169 return false; 1170 } 1171 1172 1173 // Constant pool structure for invoke methods: 1174 enum { 1175 _imcp_invoke_name = 1, // utf8: 'invokeExact', etc. 1176 _imcp_invoke_signature, // utf8: (variable Symbol*) 1177 _imcp_limit 1178 }; 1179 1180 // Test if this method is an MH adapter frame generated by Java code. 1181 // Cf. java/lang/invoke/InvokerBytecodeGenerator 1182 bool Method::is_compiled_lambda_form() const { 1183 return intrinsic_id() == vmIntrinsics::_compiledLambdaForm; 1184 } 1185 1186 // Test if this method is an internal MH primitive method. 1187 bool Method::is_method_handle_intrinsic() const { 1188 vmIntrinsics::ID iid = intrinsic_id(); 1189 return (MethodHandles::is_signature_polymorphic(iid) && 1190 MethodHandles::is_signature_polymorphic_intrinsic(iid)); 1191 } 1192 1193 bool Method::has_member_arg() const { 1194 vmIntrinsics::ID iid = intrinsic_id(); 1195 return (MethodHandles::is_signature_polymorphic(iid) && 1196 MethodHandles::has_member_arg(iid)); 1197 } 1198 1199 // Make an instance of a signature-polymorphic internal MH primitive. 1200 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid, 1201 Symbol* signature, 1202 TRAPS) { 1203 ResourceMark rm; 1204 methodHandle empty; 1205 1206 KlassHandle holder = SystemDictionary::MethodHandle_klass(); 1207 Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid); 1208 assert(iid == MethodHandles::signature_polymorphic_name_id(name), ""); 1209 if (TraceMethodHandles) { 1210 tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string()); 1211 } 1212 1213 // invariant: cp->symbol_at_put is preceded by a refcount increment (more usually a lookup) 1214 name->increment_refcount(); 1215 signature->increment_refcount(); 1216 1217 int cp_length = _imcp_limit; 1218 ClassLoaderData* loader_data = holder->class_loader_data(); 1219 constantPoolHandle cp; 1220 { 1221 ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty)); 1222 cp = constantPoolHandle(THREAD, cp_oop); 1223 } 1224 cp->set_pool_holder(InstanceKlass::cast(holder())); 1225 cp->symbol_at_put(_imcp_invoke_name, name); 1226 cp->symbol_at_put(_imcp_invoke_signature, signature); 1227 cp->set_has_preresolution(); 1228 1229 // decide on access bits: public or not? 1230 int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL); 1231 bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid); 1232 if (must_be_static) flags_bits |= JVM_ACC_STATIC; 1233 assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods"); 1234 1235 methodHandle m; 1236 { 1237 InlineTableSizes sizes; 1238 Method* m_oop = Method::allocate(loader_data, 0, 1239 accessFlags_from(flags_bits), &sizes, 1240 ConstMethod::NORMAL, CHECK_(empty)); 1241 m = methodHandle(THREAD, m_oop); 1242 } 1243 m->set_constants(cp()); 1244 m->set_name_index(_imcp_invoke_name); 1245 m->set_signature_index(_imcp_invoke_signature); 1246 assert(MethodHandles::is_signature_polymorphic_name(m->name()), ""); 1247 assert(m->signature() == signature, ""); 1248 ResultTypeFinder rtf(signature); 1249 m->constMethod()->set_result_type(rtf.type()); 1250 m->compute_size_of_parameters(THREAD); 1251 m->init_intrinsic_id(); 1252 assert(m->is_method_handle_intrinsic(), ""); 1253 #ifdef ASSERT 1254 if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id())) m->print(); 1255 assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker"); 1256 assert(m->intrinsic_id() == iid, "correctly predicted iid"); 1257 #endif //ASSERT 1258 1259 // Finally, set up its entry points. 1260 assert(m->can_be_statically_bound(), ""); 1261 m->set_vtable_index(Method::nonvirtual_vtable_index); 1262 m->link_method(m, CHECK_(empty)); 1263 1264 if (TraceMethodHandles && (Verbose || WizardMode)) { 1265 ttyLocker ttyl; 1266 m->print_on(tty); 1267 } 1268 1269 return m; 1270 } 1271 1272 Klass* Method::check_non_bcp_klass(Klass* klass) { 1273 if (klass != NULL && klass->class_loader() != NULL) { 1274 if (klass->is_objArray_klass()) 1275 klass = ObjArrayKlass::cast(klass)->bottom_klass(); 1276 return klass; 1277 } 1278 return NULL; 1279 } 1280 1281 1282 methodHandle Method::clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length, 1283 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) { 1284 // Code below does not work for native methods - they should never get rewritten anyway 1285 assert(!m->is_native(), "cannot rewrite native methods"); 1286 // Allocate new Method* 1287 AccessFlags flags = m->access_flags(); 1288 1289 ConstMethod* cm = m->constMethod(); 1290 int checked_exceptions_len = cm->checked_exceptions_length(); 1291 int localvariable_len = cm->localvariable_table_length(); 1292 int exception_table_len = cm->exception_table_length(); 1293 int method_parameters_len = cm->method_parameters_length(); 1294 int method_annotations_len = cm->method_annotations_length(); 1295 int parameter_annotations_len = cm->parameter_annotations_length(); 1296 int type_annotations_len = cm->type_annotations_length(); 1297 int default_annotations_len = cm->default_annotations_length(); 1298 1299 InlineTableSizes sizes( 1300 localvariable_len, 1301 new_compressed_linenumber_size, 1302 exception_table_len, 1303 checked_exceptions_len, 1304 method_parameters_len, 1305 cm->generic_signature_index(), 1306 method_annotations_len, 1307 parameter_annotations_len, 1308 type_annotations_len, 1309 default_annotations_len, 1310 0); 1311 1312 ClassLoaderData* loader_data = m->method_holder()->class_loader_data(); 1313 Method* newm_oop = Method::allocate(loader_data, 1314 new_code_length, 1315 flags, 1316 &sizes, 1317 m->method_type(), 1318 CHECK_(methodHandle())); 1319 methodHandle newm (THREAD, newm_oop); 1320 1321 // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod* 1322 ConstMethod* newcm = newm->constMethod(); 1323 int new_const_method_size = newm->constMethod()->size(); 1324 1325 memcpy(newm(), m(), sizeof(Method)); 1326 1327 // Create shallow copy of ConstMethod. 1328 memcpy(newcm, m->constMethod(), sizeof(ConstMethod)); 1329 1330 // Reset correct method/const method, method size, and parameter info 1331 newm->set_constMethod(newcm); 1332 newm->constMethod()->set_code_size(new_code_length); 1333 newm->constMethod()->set_constMethod_size(new_const_method_size); 1334 assert(newm->code_size() == new_code_length, "check"); 1335 assert(newm->method_parameters_length() == method_parameters_len, "check"); 1336 assert(newm->checked_exceptions_length() == checked_exceptions_len, "check"); 1337 assert(newm->exception_table_length() == exception_table_len, "check"); 1338 assert(newm->localvariable_table_length() == localvariable_len, "check"); 1339 // Copy new byte codes 1340 memcpy(newm->code_base(), new_code, new_code_length); 1341 // Copy line number table 1342 if (new_compressed_linenumber_size > 0) { 1343 memcpy(newm->compressed_linenumber_table(), 1344 new_compressed_linenumber_table, 1345 new_compressed_linenumber_size); 1346 } 1347 // Copy method_parameters 1348 if (method_parameters_len > 0) { 1349 memcpy(newm->method_parameters_start(), 1350 m->method_parameters_start(), 1351 method_parameters_len * sizeof(MethodParametersElement)); 1352 } 1353 // Copy checked_exceptions 1354 if (checked_exceptions_len > 0) { 1355 memcpy(newm->checked_exceptions_start(), 1356 m->checked_exceptions_start(), 1357 checked_exceptions_len * sizeof(CheckedExceptionElement)); 1358 } 1359 // Copy exception table 1360 if (exception_table_len > 0) { 1361 memcpy(newm->exception_table_start(), 1362 m->exception_table_start(), 1363 exception_table_len * sizeof(ExceptionTableElement)); 1364 } 1365 // Copy local variable number table 1366 if (localvariable_len > 0) { 1367 memcpy(newm->localvariable_table_start(), 1368 m->localvariable_table_start(), 1369 localvariable_len * sizeof(LocalVariableTableElement)); 1370 } 1371 // Copy stackmap table 1372 if (m->has_stackmap_table()) { 1373 int code_attribute_length = m->stackmap_data()->length(); 1374 Array<u1>* stackmap_data = 1375 MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL); 1376 memcpy((void*)stackmap_data->adr_at(0), 1377 (void*)m->stackmap_data()->adr_at(0), code_attribute_length); 1378 newm->set_stackmap_data(stackmap_data); 1379 } 1380 1381 // copy annotations over to new method 1382 newcm->copy_annotations_from(cm); 1383 return newm; 1384 } 1385 1386 vmSymbols::SID Method::klass_id_for_intrinsics(const Klass* holder) { 1387 // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics 1388 // because we are not loading from core libraries 1389 // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar 1390 // which does not use the class default class loader so we check for its loader here 1391 const InstanceKlass* ik = InstanceKlass::cast(holder); 1392 if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) { 1393 return vmSymbols::NO_SID; // regardless of name, no intrinsics here 1394 } 1395 1396 // see if the klass name is well-known: 1397 Symbol* klass_name = ik->name(); 1398 return vmSymbols::find_sid(klass_name); 1399 } 1400 1401 void Method::init_intrinsic_id() { 1402 assert(_intrinsic_id == vmIntrinsics::_none, "do this just once"); 1403 const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte)); 1404 assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size"); 1405 assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), ""); 1406 1407 // the klass name is well-known: 1408 vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder()); 1409 assert(klass_id != vmSymbols::NO_SID, "caller responsibility"); 1410 1411 // ditto for method and signature: 1412 vmSymbols::SID name_id = vmSymbols::find_sid(name()); 1413 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle) 1414 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle) 1415 && name_id == vmSymbols::NO_SID) { 1416 return; 1417 } 1418 vmSymbols::SID sig_id = vmSymbols::find_sid(signature()); 1419 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle) 1420 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle) 1421 && sig_id == vmSymbols::NO_SID) { 1422 return; 1423 } 1424 jshort flags = access_flags().as_short(); 1425 1426 vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags); 1427 if (id != vmIntrinsics::_none) { 1428 set_intrinsic_id(id); 1429 if (id == vmIntrinsics::_Class_cast) { 1430 // Even if the intrinsic is rejected, we want to inline this simple method. 1431 set_force_inline(true); 1432 } 1433 return; 1434 } 1435 1436 // A few slightly irregular cases: 1437 switch (klass_id) { 1438 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath): 1439 // Second chance: check in regular Math. 1440 switch (name_id) { 1441 case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name): 1442 case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name): 1443 case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name): 1444 // pretend it is the corresponding method in the non-strict class: 1445 klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math); 1446 id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags); 1447 break; 1448 } 1449 break; 1450 1451 // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle 1452 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle): 1453 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle): 1454 if (!is_native()) break; 1455 id = MethodHandles::signature_polymorphic_name_id(method_holder(), name()); 1456 if (is_static() != MethodHandles::is_signature_polymorphic_static(id)) 1457 id = vmIntrinsics::_none; 1458 break; 1459 } 1460 1461 if (id != vmIntrinsics::_none) { 1462 // Set up its iid. It is an alias method. 1463 set_intrinsic_id(id); 1464 return; 1465 } 1466 } 1467 1468 // These two methods are static since a GC may move the Method 1469 bool Method::load_signature_classes(methodHandle m, TRAPS) { 1470 if (!THREAD->can_call_java()) { 1471 // There is nothing useful this routine can do from within the Compile thread. 1472 // Hopefully, the signature contains only well-known classes. 1473 // We could scan for this and return true/false, but the caller won't care. 1474 return false; 1475 } 1476 bool sig_is_loaded = true; 1477 Handle class_loader(THREAD, m->method_holder()->class_loader()); 1478 Handle protection_domain(THREAD, m->method_holder()->protection_domain()); 1479 ResourceMark rm(THREAD); 1480 Symbol* signature = m->signature(); 1481 for(SignatureStream ss(signature); !ss.is_done(); ss.next()) { 1482 if (ss.is_object()) { 1483 Symbol* sym = ss.as_symbol(CHECK_(false)); 1484 Symbol* name = sym; 1485 Klass* klass = SystemDictionary::resolve_or_null(name, class_loader, 1486 protection_domain, THREAD); 1487 // We are loading classes eagerly. If a ClassNotFoundException or 1488 // a LinkageError was generated, be sure to ignore it. 1489 if (HAS_PENDING_EXCEPTION) { 1490 if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) || 1491 PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) { 1492 CLEAR_PENDING_EXCEPTION; 1493 } else { 1494 return false; 1495 } 1496 } 1497 if( klass == NULL) { sig_is_loaded = false; } 1498 } 1499 } 1500 return sig_is_loaded; 1501 } 1502 1503 bool Method::has_unloaded_classes_in_signature(methodHandle m, TRAPS) { 1504 Handle class_loader(THREAD, m->method_holder()->class_loader()); 1505 Handle protection_domain(THREAD, m->method_holder()->protection_domain()); 1506 ResourceMark rm(THREAD); 1507 Symbol* signature = m->signature(); 1508 for(SignatureStream ss(signature); !ss.is_done(); ss.next()) { 1509 if (ss.type() == T_OBJECT) { 1510 Symbol* name = ss.as_symbol_or_null(); 1511 if (name == NULL) return true; 1512 Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD); 1513 if (klass == NULL) return true; 1514 } 1515 } 1516 return false; 1517 } 1518 1519 // Exposed so field engineers can debug VM 1520 void Method::print_short_name(outputStream* st) { 1521 ResourceMark rm; 1522 #ifdef PRODUCT 1523 st->print(" %s::", method_holder()->external_name()); 1524 #else 1525 st->print(" %s::", method_holder()->internal_name()); 1526 #endif 1527 name()->print_symbol_on(st); 1528 if (WizardMode) signature()->print_symbol_on(st); 1529 else if (MethodHandles::is_signature_polymorphic(intrinsic_id())) 1530 MethodHandles::print_as_basic_type_signature_on(st, signature(), true); 1531 } 1532 1533 // Comparer for sorting an object array containing 1534 // Method*s. 1535 static int method_comparator(Method* a, Method* b) { 1536 return a->name()->fast_compare(b->name()); 1537 } 1538 1539 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array 1540 // default_methods also uses this without the ordering for fast find_method 1541 void Method::sort_methods(Array<Method*>* methods, bool idempotent, bool set_idnums) { 1542 int length = methods->length(); 1543 if (length > 1) { 1544 { 1545 NoSafepointVerifier nsv; 1546 QuickSort::sort<Method*>(methods->data(), length, method_comparator, idempotent); 1547 } 1548 // Reset method ordering 1549 if (set_idnums) { 1550 for (int i = 0; i < length; i++) { 1551 Method* m = methods->at(i); 1552 m->set_method_idnum(i); 1553 m->set_orig_method_idnum(i); 1554 } 1555 } 1556 } 1557 } 1558 1559 //----------------------------------------------------------------------------------- 1560 // Non-product code unless JVM/TI needs it 1561 1562 #if !defined(PRODUCT) || INCLUDE_JVMTI 1563 class SignatureTypePrinter : public SignatureTypeNames { 1564 private: 1565 outputStream* _st; 1566 bool _use_separator; 1567 1568 void type_name(const char* name) { 1569 if (_use_separator) _st->print(", "); 1570 _st->print("%s", name); 1571 _use_separator = true; 1572 } 1573 1574 public: 1575 SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) { 1576 _st = st; 1577 _use_separator = false; 1578 } 1579 1580 void print_parameters() { _use_separator = false; iterate_parameters(); } 1581 void print_returntype() { _use_separator = false; iterate_returntype(); } 1582 }; 1583 1584 1585 void Method::print_name(outputStream* st) { 1586 Thread *thread = Thread::current(); 1587 ResourceMark rm(thread); 1588 st->print("%s ", is_static() ? "static" : "virtual"); 1589 if (WizardMode) { 1590 st->print("%s.", method_holder()->internal_name()); 1591 name()->print_symbol_on(st); 1592 signature()->print_symbol_on(st); 1593 } else { 1594 SignatureTypePrinter sig(signature(), st); 1595 sig.print_returntype(); 1596 st->print(" %s.", method_holder()->internal_name()); 1597 name()->print_symbol_on(st); 1598 st->print("("); 1599 sig.print_parameters(); 1600 st->print(")"); 1601 } 1602 } 1603 #endif // !PRODUCT || INCLUDE_JVMTI 1604 1605 1606 void Method::print_codes_on(outputStream* st) const { 1607 print_codes_on(0, code_size(), st); 1608 } 1609 1610 void Method::print_codes_on(int from, int to, outputStream* st) const { 1611 Thread *thread = Thread::current(); 1612 ResourceMark rm(thread); 1613 methodHandle mh (thread, (Method*)this); 1614 BytecodeStream s(mh); 1615 s.set_interval(from, to); 1616 BytecodeTracer::set_closure(BytecodeTracer::std_closure()); 1617 while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st); 1618 } 1619 1620 1621 // Simple compression of line number tables. We use a regular compressed stream, except that we compress deltas 1622 // between (bci,line) pairs since they are smaller. If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned) 1623 // we save it as one byte, otherwise we write a 0xFF escape character and use regular compression. 0x0 is used 1624 // as end-of-stream terminator. 1625 1626 void CompressedLineNumberWriteStream::write_pair_regular(int bci_delta, int line_delta) { 1627 // bci and line number does not compress into single byte. 1628 // Write out escape character and use regular compression for bci and line number. 1629 write_byte((jubyte)0xFF); 1630 write_signed_int(bci_delta); 1631 write_signed_int(line_delta); 1632 } 1633 1634 // See comment in method.hpp which explains why this exists. 1635 #if defined(_M_AMD64) && _MSC_VER >= 1400 1636 #pragma optimize("", off) 1637 void CompressedLineNumberWriteStream::write_pair(int bci, int line) { 1638 write_pair_inline(bci, line); 1639 } 1640 #pragma optimize("", on) 1641 #endif 1642 1643 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) { 1644 _bci = 0; 1645 _line = 0; 1646 }; 1647 1648 1649 bool CompressedLineNumberReadStream::read_pair() { 1650 jubyte next = read_byte(); 1651 // Check for terminator 1652 if (next == 0) return false; 1653 if (next == 0xFF) { 1654 // Escape character, regular compression used 1655 _bci += read_signed_int(); 1656 _line += read_signed_int(); 1657 } else { 1658 // Single byte compression used 1659 _bci += next >> 3; 1660 _line += next & 0x7; 1661 } 1662 return true; 1663 } 1664 1665 #if INCLUDE_JVMTI 1666 1667 Bytecodes::Code Method::orig_bytecode_at(int bci) const { 1668 BreakpointInfo* bp = method_holder()->breakpoints(); 1669 for (; bp != NULL; bp = bp->next()) { 1670 if (bp->match(this, bci)) { 1671 return bp->orig_bytecode(); 1672 } 1673 } 1674 { 1675 ResourceMark rm; 1676 fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci); 1677 } 1678 return Bytecodes::_shouldnotreachhere; 1679 } 1680 1681 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) { 1682 assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way"); 1683 BreakpointInfo* bp = method_holder()->breakpoints(); 1684 for (; bp != NULL; bp = bp->next()) { 1685 if (bp->match(this, bci)) { 1686 bp->set_orig_bytecode(code); 1687 // and continue, in case there is more than one 1688 } 1689 } 1690 } 1691 1692 void Method::set_breakpoint(int bci) { 1693 InstanceKlass* ik = method_holder(); 1694 BreakpointInfo *bp = new BreakpointInfo(this, bci); 1695 bp->set_next(ik->breakpoints()); 1696 ik->set_breakpoints(bp); 1697 // do this last: 1698 bp->set(this); 1699 } 1700 1701 static void clear_matches(Method* m, int bci) { 1702 InstanceKlass* ik = m->method_holder(); 1703 BreakpointInfo* prev_bp = NULL; 1704 BreakpointInfo* next_bp; 1705 for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) { 1706 next_bp = bp->next(); 1707 // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint). 1708 if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) { 1709 // do this first: 1710 bp->clear(m); 1711 // unhook it 1712 if (prev_bp != NULL) 1713 prev_bp->set_next(next_bp); 1714 else 1715 ik->set_breakpoints(next_bp); 1716 delete bp; 1717 // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods 1718 // at same location. So we have multiple matching (method_index and bci) 1719 // BreakpointInfo nodes in BreakpointInfo list. We should just delete one 1720 // breakpoint for clear_breakpoint request and keep all other method versions 1721 // BreakpointInfo for future clear_breakpoint request. 1722 // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints) 1723 // which is being called when class is unloaded. We delete all the Breakpoint 1724 // information for all versions of method. We may not correctly restore the original 1725 // bytecode in all method versions, but that is ok. Because the class is being unloaded 1726 // so these methods won't be used anymore. 1727 if (bci >= 0) { 1728 break; 1729 } 1730 } else { 1731 // This one is a keeper. 1732 prev_bp = bp; 1733 } 1734 } 1735 } 1736 1737 void Method::clear_breakpoint(int bci) { 1738 assert(bci >= 0, ""); 1739 clear_matches(this, bci); 1740 } 1741 1742 void Method::clear_all_breakpoints() { 1743 clear_matches(this, -1); 1744 } 1745 1746 #endif // INCLUDE_JVMTI 1747 1748 int Method::invocation_count() { 1749 MethodCounters *mcs = method_counters(); 1750 if (TieredCompilation) { 1751 MethodData* const mdo = method_data(); 1752 if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) || 1753 ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) { 1754 return InvocationCounter::count_limit; 1755 } else { 1756 return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) + 1757 ((mdo != NULL) ? mdo->invocation_counter()->count() : 0); 1758 } 1759 } else { 1760 return (mcs == NULL) ? 0 : mcs->invocation_counter()->count(); 1761 } 1762 } 1763 1764 int Method::backedge_count() { 1765 MethodCounters *mcs = method_counters(); 1766 if (TieredCompilation) { 1767 MethodData* const mdo = method_data(); 1768 if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) || 1769 ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) { 1770 return InvocationCounter::count_limit; 1771 } else { 1772 return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) + 1773 ((mdo != NULL) ? mdo->backedge_counter()->count() : 0); 1774 } 1775 } else { 1776 return (mcs == NULL) ? 0 : mcs->backedge_counter()->count(); 1777 } 1778 } 1779 1780 int Method::highest_comp_level() const { 1781 const MethodCounters* mcs = method_counters(); 1782 if (mcs != NULL) { 1783 return mcs->highest_comp_level(); 1784 } else { 1785 return CompLevel_none; 1786 } 1787 } 1788 1789 int Method::highest_osr_comp_level() const { 1790 const MethodCounters* mcs = method_counters(); 1791 if (mcs != NULL) { 1792 return mcs->highest_osr_comp_level(); 1793 } else { 1794 return CompLevel_none; 1795 } 1796 } 1797 1798 void Method::set_highest_comp_level(int level) { 1799 MethodCounters* mcs = method_counters(); 1800 if (mcs != NULL) { 1801 mcs->set_highest_comp_level(level); 1802 } 1803 } 1804 1805 void Method::set_highest_osr_comp_level(int level) { 1806 MethodCounters* mcs = method_counters(); 1807 if (mcs != NULL) { 1808 mcs->set_highest_osr_comp_level(level); 1809 } 1810 } 1811 1812 #if INCLUDE_JVMTI 1813 1814 BreakpointInfo::BreakpointInfo(Method* m, int bci) { 1815 _bci = bci; 1816 _name_index = m->name_index(); 1817 _signature_index = m->signature_index(); 1818 _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci); 1819 if (_orig_bytecode == Bytecodes::_breakpoint) 1820 _orig_bytecode = m->orig_bytecode_at(_bci); 1821 _next = NULL; 1822 } 1823 1824 void BreakpointInfo::set(Method* method) { 1825 #ifdef ASSERT 1826 { 1827 Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci); 1828 if (code == Bytecodes::_breakpoint) 1829 code = method->orig_bytecode_at(_bci); 1830 assert(orig_bytecode() == code, "original bytecode must be the same"); 1831 } 1832 #endif 1833 Thread *thread = Thread::current(); 1834 *method->bcp_from(_bci) = Bytecodes::_breakpoint; 1835 method->incr_number_of_breakpoints(thread); 1836 SystemDictionary::notice_modification(); 1837 { 1838 // Deoptimize all dependents on this method 1839 HandleMark hm(thread); 1840 methodHandle mh(thread, method); 1841 CodeCache::flush_dependents_on_method(mh); 1842 } 1843 } 1844 1845 void BreakpointInfo::clear(Method* method) { 1846 *method->bcp_from(_bci) = orig_bytecode(); 1847 assert(method->number_of_breakpoints() > 0, "must not go negative"); 1848 method->decr_number_of_breakpoints(Thread::current()); 1849 } 1850 1851 #endif // INCLUDE_JVMTI 1852 1853 // jmethodID handling 1854 1855 // This is a block allocating object, sort of like JNIHandleBlock, only a 1856 // lot simpler. 1857 // It's allocated on the CHeap because once we allocate a jmethodID, we can 1858 // never get rid of it. 1859 1860 static const int min_block_size = 8; 1861 1862 class JNIMethodBlockNode : public CHeapObj<mtClass> { 1863 friend class JNIMethodBlock; 1864 Method** _methods; 1865 int _number_of_methods; 1866 int _top; 1867 JNIMethodBlockNode* _next; 1868 1869 public: 1870 1871 JNIMethodBlockNode(int num_methods = min_block_size); 1872 1873 ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); } 1874 1875 void ensure_methods(int num_addl_methods) { 1876 if (_top < _number_of_methods) { 1877 num_addl_methods -= _number_of_methods - _top; 1878 if (num_addl_methods <= 0) { 1879 return; 1880 } 1881 } 1882 if (_next == NULL) { 1883 _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size)); 1884 } else { 1885 _next->ensure_methods(num_addl_methods); 1886 } 1887 } 1888 }; 1889 1890 class JNIMethodBlock : public CHeapObj<mtClass> { 1891 JNIMethodBlockNode _head; 1892 JNIMethodBlockNode *_last_free; 1893 public: 1894 static Method* const _free_method; 1895 1896 JNIMethodBlock(int initial_capacity = min_block_size) 1897 : _head(initial_capacity), _last_free(&_head) {} 1898 1899 void ensure_methods(int num_addl_methods) { 1900 _last_free->ensure_methods(num_addl_methods); 1901 } 1902 1903 Method** add_method(Method* m) { 1904 for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) { 1905 if (b->_top < b->_number_of_methods) { 1906 // top points to the next free entry. 1907 int i = b->_top; 1908 b->_methods[i] = m; 1909 b->_top++; 1910 _last_free = b; 1911 return &(b->_methods[i]); 1912 } else if (b->_top == b->_number_of_methods) { 1913 // if the next free entry ran off the block see if there's a free entry 1914 for (int i = 0; i < b->_number_of_methods; i++) { 1915 if (b->_methods[i] == _free_method) { 1916 b->_methods[i] = m; 1917 _last_free = b; 1918 return &(b->_methods[i]); 1919 } 1920 } 1921 // Only check each block once for frees. They're very unlikely. 1922 // Increment top past the end of the block. 1923 b->_top++; 1924 } 1925 // need to allocate a next block. 1926 if (b->_next == NULL) { 1927 b->_next = _last_free = new JNIMethodBlockNode(); 1928 } 1929 } 1930 guarantee(false, "Should always allocate a free block"); 1931 return NULL; 1932 } 1933 1934 bool contains(Method** m) { 1935 if (m == NULL) return false; 1936 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) { 1937 if (b->_methods <= m && m < b->_methods + b->_number_of_methods) { 1938 // This is a bit of extra checking, for two reasons. One is 1939 // that contains() deals with pointers that are passed in by 1940 // JNI code, so making sure that the pointer is aligned 1941 // correctly is valuable. The other is that <= and > are 1942 // technically not defined on pointers, so the if guard can 1943 // pass spuriously; no modern compiler is likely to make that 1944 // a problem, though (and if one did, the guard could also 1945 // fail spuriously, which would be bad). 1946 ptrdiff_t idx = m - b->_methods; 1947 if (b->_methods + idx == m) { 1948 return true; 1949 } 1950 } 1951 } 1952 return false; // not found 1953 } 1954 1955 // Doesn't really destroy it, just marks it as free so it can be reused. 1956 void destroy_method(Method** m) { 1957 #ifdef ASSERT 1958 assert(contains(m), "should be a methodID"); 1959 #endif // ASSERT 1960 *m = _free_method; 1961 } 1962 1963 // During class unloading the methods are cleared, which is different 1964 // than freed. 1965 void clear_all_methods() { 1966 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) { 1967 for (int i = 0; i< b->_number_of_methods; i++) { 1968 b->_methods[i] = NULL; 1969 } 1970 } 1971 } 1972 #ifndef PRODUCT 1973 int count_methods() { 1974 // count all allocated methods 1975 int count = 0; 1976 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) { 1977 for (int i = 0; i< b->_number_of_methods; i++) { 1978 if (b->_methods[i] != _free_method) count++; 1979 } 1980 } 1981 return count; 1982 } 1983 #endif // PRODUCT 1984 }; 1985 1986 // Something that can't be mistaken for an address or a markOop 1987 Method* const JNIMethodBlock::_free_method = (Method*)55; 1988 1989 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _next(NULL), _top(0) { 1990 _number_of_methods = MAX2(num_methods, min_block_size); 1991 _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal); 1992 for (int i = 0; i < _number_of_methods; i++) { 1993 _methods[i] = JNIMethodBlock::_free_method; 1994 } 1995 } 1996 1997 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) { 1998 ClassLoaderData* cld = loader_data; 1999 if (!SafepointSynchronize::is_at_safepoint()) { 2000 // Have to add jmethod_ids() to class loader data thread-safely. 2001 // Also have to add the method to the list safely, which the cld lock 2002 // protects as well. 2003 MutexLockerEx ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag); 2004 if (cld->jmethod_ids() == NULL) { 2005 cld->set_jmethod_ids(new JNIMethodBlock(capacity)); 2006 } else { 2007 cld->jmethod_ids()->ensure_methods(capacity); 2008 } 2009 } else { 2010 // At safepoint, we are single threaded and can set this. 2011 if (cld->jmethod_ids() == NULL) { 2012 cld->set_jmethod_ids(new JNIMethodBlock(capacity)); 2013 } else { 2014 cld->jmethod_ids()->ensure_methods(capacity); 2015 } 2016 } 2017 } 2018 2019 // Add a method id to the jmethod_ids 2020 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) { 2021 ClassLoaderData* cld = loader_data; 2022 2023 if (!SafepointSynchronize::is_at_safepoint()) { 2024 // Have to add jmethod_ids() to class loader data thread-safely. 2025 // Also have to add the method to the list safely, which the cld lock 2026 // protects as well. 2027 MutexLockerEx ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag); 2028 if (cld->jmethod_ids() == NULL) { 2029 cld->set_jmethod_ids(new JNIMethodBlock()); 2030 } 2031 // jmethodID is a pointer to Method* 2032 return (jmethodID)cld->jmethod_ids()->add_method(m); 2033 } else { 2034 // At safepoint, we are single threaded and can set this. 2035 if (cld->jmethod_ids() == NULL) { 2036 cld->set_jmethod_ids(new JNIMethodBlock()); 2037 } 2038 // jmethodID is a pointer to Method* 2039 return (jmethodID)cld->jmethod_ids()->add_method(m); 2040 } 2041 } 2042 2043 // Mark a jmethodID as free. This is called when there is a data race in 2044 // InstanceKlass while creating the jmethodID cache. 2045 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) { 2046 ClassLoaderData* cld = loader_data; 2047 Method** ptr = (Method**)m; 2048 assert(cld->jmethod_ids() != NULL, "should have method handles"); 2049 cld->jmethod_ids()->destroy_method(ptr); 2050 } 2051 2052 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) { 2053 // Can't assert the method_holder is the same because the new method has the 2054 // scratch method holder. 2055 assert(resolve_jmethod_id(jmid)->method_holder()->class_loader() 2056 == new_method->method_holder()->class_loader(), 2057 "changing to a different class loader"); 2058 // Just change the method in place, jmethodID pointer doesn't change. 2059 *((Method**)jmid) = new_method; 2060 } 2061 2062 bool Method::is_method_id(jmethodID mid) { 2063 Method* m = resolve_jmethod_id(mid); 2064 assert(m != NULL, "should be called with non-null method"); 2065 InstanceKlass* ik = m->method_holder(); 2066 ClassLoaderData* cld = ik->class_loader_data(); 2067 if (cld->jmethod_ids() == NULL) return false; 2068 return (cld->jmethod_ids()->contains((Method**)mid)); 2069 } 2070 2071 Method* Method::checked_resolve_jmethod_id(jmethodID mid) { 2072 if (mid == NULL) return NULL; 2073 Method* o = resolve_jmethod_id(mid); 2074 if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) { 2075 return NULL; 2076 } 2077 return o; 2078 }; 2079 2080 void Method::set_on_stack(const bool value) { 2081 // Set both the method itself and its constant pool. The constant pool 2082 // on stack means some method referring to it is also on the stack. 2083 constants()->set_on_stack(value); 2084 2085 bool already_set = on_stack(); 2086 _access_flags.set_on_stack(value); 2087 if (value && !already_set) { 2088 MetadataOnStackMark::record(this); 2089 } 2090 } 2091 2092 // Called when the class loader is unloaded to make all methods weak. 2093 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) { 2094 loader_data->jmethod_ids()->clear_all_methods(); 2095 } 2096 2097 bool Method::has_method_vptr(const void* ptr) { 2098 Method m; 2099 // This assumes that the vtbl pointer is the first word of a C++ object. 2100 // This assumption is also in universe.cpp patch_klass_vtble 2101 return dereference_vptr(&m) == dereference_vptr(ptr); 2102 } 2103 2104 // Check that this pointer is valid by checking that the vtbl pointer matches 2105 bool Method::is_valid_method() const { 2106 if (this == NULL) { 2107 return false; 2108 } else if ((intptr_t(this) & (wordSize-1)) != 0) { 2109 // Quick sanity check on pointer. 2110 return false; 2111 } else if (!is_metaspace_object()) { 2112 return false; 2113 } else { 2114 return has_method_vptr((const void*)this); 2115 } 2116 } 2117 2118 #ifndef PRODUCT 2119 void Method::print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) { 2120 out->print_cr("jni_method_id count = %d", loader_data->jmethod_ids()->count_methods()); 2121 } 2122 #endif // PRODUCT 2123 2124 2125 // Printing 2126 2127 #ifndef PRODUCT 2128 2129 void Method::print_on(outputStream* st) const { 2130 ResourceMark rm; 2131 assert(is_method(), "must be method"); 2132 st->print_cr("%s", internal_name()); 2133 // get the effect of PrintOopAddress, always, for methods: 2134 st->print_cr(" - this oop: " INTPTR_FORMAT, p2i(this)); 2135 st->print (" - method holder: "); method_holder()->print_value_on(st); st->cr(); 2136 st->print (" - constants: " INTPTR_FORMAT " ", p2i(constants())); 2137 constants()->print_value_on(st); st->cr(); 2138 st->print (" - access: 0x%x ", access_flags().as_int()); access_flags().print_on(st); st->cr(); 2139 st->print (" - name: "); name()->print_value_on(st); st->cr(); 2140 st->print (" - signature: "); signature()->print_value_on(st); st->cr(); 2141 st->print_cr(" - max stack: %d", max_stack()); 2142 st->print_cr(" - max locals: %d", max_locals()); 2143 st->print_cr(" - size of params: %d", size_of_parameters()); 2144 st->print_cr(" - method size: %d", method_size()); 2145 if (intrinsic_id() != vmIntrinsics::_none) 2146 st->print_cr(" - intrinsic id: %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id())); 2147 if (highest_comp_level() != CompLevel_none) 2148 st->print_cr(" - highest level: %d", highest_comp_level()); 2149 st->print_cr(" - vtable index: %d", _vtable_index); 2150 st->print_cr(" - i2i entry: " INTPTR_FORMAT, p2i(interpreter_entry())); 2151 st->print( " - adapters: "); 2152 AdapterHandlerEntry* a = ((Method*)this)->adapter(); 2153 if (a == NULL) 2154 st->print_cr(INTPTR_FORMAT, p2i(a)); 2155 else 2156 a->print_adapter_on(st); 2157 st->print_cr(" - compiled entry " INTPTR_FORMAT, p2i(from_compiled_entry())); 2158 st->print_cr(" - code size: %d", code_size()); 2159 if (code_size() != 0) { 2160 st->print_cr(" - code start: " INTPTR_FORMAT, p2i(code_base())); 2161 st->print_cr(" - code end (excl): " INTPTR_FORMAT, p2i(code_base() + code_size())); 2162 } 2163 if (method_data() != NULL) { 2164 st->print_cr(" - method data: " INTPTR_FORMAT, p2i(method_data())); 2165 } 2166 st->print_cr(" - checked ex length: %d", checked_exceptions_length()); 2167 if (checked_exceptions_length() > 0) { 2168 CheckedExceptionElement* table = checked_exceptions_start(); 2169 st->print_cr(" - checked ex start: " INTPTR_FORMAT, p2i(table)); 2170 if (Verbose) { 2171 for (int i = 0; i < checked_exceptions_length(); i++) { 2172 st->print_cr(" - throws %s", constants()->printable_name_at(table[i].class_cp_index)); 2173 } 2174 } 2175 } 2176 if (has_linenumber_table()) { 2177 u_char* table = compressed_linenumber_table(); 2178 st->print_cr(" - linenumber start: " INTPTR_FORMAT, p2i(table)); 2179 if (Verbose) { 2180 CompressedLineNumberReadStream stream(table); 2181 while (stream.read_pair()) { 2182 st->print_cr(" - line %d: %d", stream.line(), stream.bci()); 2183 } 2184 } 2185 } 2186 st->print_cr(" - localvar length: %d", localvariable_table_length()); 2187 if (localvariable_table_length() > 0) { 2188 LocalVariableTableElement* table = localvariable_table_start(); 2189 st->print_cr(" - localvar start: " INTPTR_FORMAT, p2i(table)); 2190 if (Verbose) { 2191 for (int i = 0; i < localvariable_table_length(); i++) { 2192 int bci = table[i].start_bci; 2193 int len = table[i].length; 2194 const char* name = constants()->printable_name_at(table[i].name_cp_index); 2195 const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index); 2196 int slot = table[i].slot; 2197 st->print_cr(" - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot); 2198 } 2199 } 2200 } 2201 if (code() != NULL) { 2202 st->print (" - compiled code: "); 2203 code()->print_value_on(st); 2204 } 2205 if (is_native()) { 2206 st->print_cr(" - native function: " INTPTR_FORMAT, p2i(native_function())); 2207 st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler())); 2208 } 2209 } 2210 2211 void Method::print_linkage_flags(outputStream* st) { 2212 access_flags().print_on(st); 2213 if (is_default_method()) { 2214 st->print("default "); 2215 } 2216 if (is_overpass()) { 2217 st->print("overpass "); 2218 } 2219 } 2220 #endif //PRODUCT 2221 2222 void Method::print_value_on(outputStream* st) const { 2223 assert(is_method(), "must be method"); 2224 st->print("%s", internal_name()); 2225 print_address_on(st); 2226 st->print(" "); 2227 name()->print_value_on(st); 2228 st->print(" "); 2229 signature()->print_value_on(st); 2230 st->print(" in "); 2231 method_holder()->print_value_on(st); 2232 if (WizardMode) st->print("#%d", _vtable_index); 2233 if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals()); 2234 if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code()); 2235 } 2236 2237 #if INCLUDE_SERVICES 2238 // Size Statistics 2239 void Method::collect_statistics(KlassSizeStats *sz) const { 2240 int mysize = sz->count(this); 2241 sz->_method_bytes += mysize; 2242 sz->_method_all_bytes += mysize; 2243 sz->_rw_bytes += mysize; 2244 2245 if (constMethod()) { 2246 constMethod()->collect_statistics(sz); 2247 } 2248 if (method_data()) { 2249 method_data()->collect_statistics(sz); 2250 } 2251 } 2252 #endif // INCLUDE_SERVICES 2253 2254 // LogTouchedMethods and PrintTouchedMethods 2255 2256 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because 2257 // the Method may be garbage collected. Let's roll our own hash table. 2258 class TouchedMethodRecord : CHeapObj<mtTracing> { 2259 public: 2260 // It's OK to store Symbols here because they will NOT be GC'ed if 2261 // LogTouchedMethods is enabled. 2262 TouchedMethodRecord* _next; 2263 Symbol* _class_name; 2264 Symbol* _method_name; 2265 Symbol* _method_signature; 2266 }; 2267 2268 static const int TOUCHED_METHOD_TABLE_SIZE = 20011; 2269 static TouchedMethodRecord** _touched_method_table = NULL; 2270 2271 void Method::log_touched(TRAPS) { 2272 2273 const int table_size = TOUCHED_METHOD_TABLE_SIZE; 2274 Symbol* my_class = klass_name(); 2275 Symbol* my_name = name(); 2276 Symbol* my_sig = signature(); 2277 2278 unsigned int hash = my_class->identity_hash() + 2279 my_name->identity_hash() + 2280 my_sig->identity_hash(); 2281 juint index = juint(hash) % table_size; 2282 2283 MutexLocker ml(TouchedMethodLog_lock, THREAD); 2284 if (_touched_method_table == NULL) { 2285 _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size, 2286 mtTracing, CURRENT_PC); 2287 memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size); 2288 } 2289 2290 TouchedMethodRecord* ptr = _touched_method_table[index]; 2291 while (ptr) { 2292 if (ptr->_class_name == my_class && 2293 ptr->_method_name == my_name && 2294 ptr->_method_signature == my_sig) { 2295 return; 2296 } 2297 if (ptr->_next == NULL) break; 2298 ptr = ptr->_next; 2299 } 2300 TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing); 2301 my_class->set_permanent(); // prevent reclaimed by GC 2302 my_name->set_permanent(); 2303 my_sig->set_permanent(); 2304 nptr->_class_name = my_class; 2305 nptr->_method_name = my_name; 2306 nptr->_method_signature = my_sig; 2307 nptr->_next = NULL; 2308 2309 if (ptr == NULL) { 2310 // first 2311 _touched_method_table[index] = nptr; 2312 } else { 2313 ptr->_next = nptr; 2314 } 2315 } 2316 2317 void Method::print_touched_methods(outputStream* out) { 2318 MutexLockerEx ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock); 2319 out->print_cr("# Method::print_touched_methods version 1"); 2320 if (_touched_method_table) { 2321 for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) { 2322 TouchedMethodRecord* ptr = _touched_method_table[i]; 2323 while(ptr) { 2324 ptr->_class_name->print_symbol_on(out); out->print("."); 2325 ptr->_method_name->print_symbol_on(out); out->print(":"); 2326 ptr->_method_signature->print_symbol_on(out); out->cr(); 2327 ptr = ptr->_next; 2328 } 2329 } 2330 } 2331 } 2332 2333 // Verification 2334 2335 void Method::verify_on(outputStream* st) { 2336 guarantee(is_method(), "object must be method"); 2337 guarantee(constants()->is_constantPool(), "should be constant pool"); 2338 guarantee(constMethod()->is_constMethod(), "should be ConstMethod*"); 2339 MethodData* md = method_data(); 2340 guarantee(md == NULL || 2341 md->is_methodData(), "should be method data"); 2342 }