1 /*
   2  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/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/metaspaceClosure.hpp"
  41 #include "memory/metaspaceShared.hpp"
  42 #include "memory/oopFactory.hpp"
  43 #include "memory/resourceArea.hpp"
  44 #include "oops/constMethod.hpp"
  45 #include "oops/method.hpp"
  46 #include "oops/methodData.hpp"
  47 #include "oops/objArrayOop.inline.hpp"
  48 #include "oops/oop.inline.hpp"
  49 #include "oops/symbol.hpp"
  50 #include "prims/jvmtiExport.hpp"
  51 #include "prims/methodHandles.hpp"
  52 #include "prims/nativeLookup.hpp"
  53 #include "runtime/arguments.hpp"
  54 #include "runtime/compilationPolicy.hpp"
  55 #include "runtime/frame.inline.hpp"
  56 #include "runtime/handles.inline.hpp"
  57 #include "runtime/init.hpp"
  58 #include "runtime/orderAccess.inline.hpp"
  59 #include "runtime/relocator.hpp"
  60 #include "runtime/sharedRuntime.hpp"
  61 #include "runtime/signature.hpp"
  62 #include "utilities/align.hpp"
  63 #include "utilities/quickSort.hpp"
  64 #include "utilities/vmError.hpp"
  65 #include "utilities/xmlstream.hpp"
  66 
  67 // Implementation of Method
  68 
  69 Method* Method::allocate(ClassLoaderData* loader_data,
  70                          int byte_code_size,
  71                          AccessFlags access_flags,
  72                          InlineTableSizes* sizes,
  73                          ConstMethod::MethodType method_type,
  74                          TRAPS) {
  75   assert(!access_flags.is_native() || byte_code_size == 0,
  76          "native methods should not contain byte codes");
  77   ConstMethod* cm = ConstMethod::allocate(loader_data,
  78                                           byte_code_size,
  79                                           sizes,
  80                                           method_type,
  81                                           CHECK_NULL);
  82   int size = Method::size(access_flags.is_native());
  83   return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
  84 }
  85 
  86 Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
  87   NoSafepointVerifier no_safepoint;
  88   set_constMethod(xconst);
  89   set_access_flags(access_flags);
  90   set_intrinsic_id(vmIntrinsics::_none);
  91   set_force_inline(false);
  92   set_hidden(false);
  93   set_dont_inline(false);
  94   set_has_injected_profile(false);
  95   set_method_data(NULL);
  96   clear_method_counters();
  97   set_vtable_index(Method::garbage_vtable_index);
  98 
  99   // Fix and bury in Method*
 100   set_interpreter_entry(NULL); // sets i2i entry and from_int
 101   set_adapter_entry(NULL);
 102   clear_code(false /* don't need a lock */); // from_c/from_i get set to c2i/i2i
 103 
 104   if (access_flags.is_native()) {
 105     clear_native_function();
 106     set_signature_handler(NULL);
 107   }
 108 
 109   NOT_PRODUCT(set_compiled_invocation_count(0);)
 110 }
 111 
 112 // Release Method*.  The nmethod will be gone when we get here because
 113 // we've walked the code cache.
 114 void Method::deallocate_contents(ClassLoaderData* loader_data) {
 115   MetadataFactory::free_metadata(loader_data, constMethod());
 116   set_constMethod(NULL);
 117   MetadataFactory::free_metadata(loader_data, method_data());
 118   set_method_data(NULL);
 119   MetadataFactory::free_metadata(loader_data, method_counters());
 120   clear_method_counters();
 121   // The nmethod will be gone when we get here.
 122   if (code() != NULL) _code = NULL;
 123 }
 124 
 125 address Method::get_i2c_entry() {
 126   assert(adapter() != NULL, "must have");
 127   return adapter()->get_i2c_entry();
 128 }
 129 
 130 address Method::get_c2i_entry() {
 131   assert(adapter() != NULL, "must have");
 132   return adapter()->get_c2i_entry();
 133 }
 134 
 135 address Method::get_c2i_unverified_entry() {
 136   assert(adapter() != NULL, "must have");
 137   return adapter()->get_c2i_unverified_entry();
 138 }
 139 
 140 char* Method::name_and_sig_as_C_string() const {
 141   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
 142 }
 143 
 144 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
 145   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
 146 }
 147 
 148 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
 149   const char* klass_name = klass->external_name();
 150   int klass_name_len  = (int)strlen(klass_name);
 151   int method_name_len = method_name->utf8_length();
 152   int len             = klass_name_len + 1 + method_name_len + signature->utf8_length();
 153   char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);
 154   strcpy(dest, klass_name);
 155   dest[klass_name_len] = '.';
 156   strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
 157   strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
 158   dest[len] = 0;
 159   return dest;
 160 }
 161 
 162 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
 163   Symbol* klass_name = klass->name();
 164   klass_name->as_klass_external_name(buf, size);
 165   int len = (int)strlen(buf);
 166 
 167   if (len < size - 1) {
 168     buf[len++] = '.';
 169 
 170     method_name->as_C_string(&(buf[len]), size - len);
 171     len = (int)strlen(buf);
 172 
 173     signature->as_C_string(&(buf[len]), size - len);
 174   }
 175 
 176   return buf;
 177 }
 178 
 179 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
 180   // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
 181   // access exception table
 182   ExceptionTable table(mh());
 183   int length = table.length();
 184   // iterate through all entries sequentially
 185   constantPoolHandle pool(THREAD, mh->constants());
 186   for (int i = 0; i < length; i ++) {
 187     //reacquire the table in case a GC happened
 188     ExceptionTable table(mh());
 189     int beg_bci = table.start_pc(i);
 190     int end_bci = table.end_pc(i);
 191     assert(beg_bci <= end_bci, "inconsistent exception table");
 192     if (beg_bci <= throw_bci && throw_bci < end_bci) {
 193       // exception handler bci range covers throw_bci => investigate further
 194       int handler_bci = table.handler_pc(i);
 195       int klass_index = table.catch_type_index(i);
 196       if (klass_index == 0) {
 197         return handler_bci;
 198       } else if (ex_klass == NULL) {
 199         return handler_bci;
 200       } else {
 201         // we know the exception class => get the constraint class
 202         // this may require loading of the constraint class; if verification
 203         // fails or some other exception occurs, return handler_bci
 204         Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
 205         assert(k != NULL, "klass not loaded");
 206         if (ex_klass->is_subtype_of(k)) {
 207           return handler_bci;
 208         }
 209       }
 210     }
 211   }
 212 
 213   return -1;
 214 }
 215 
 216 void Method::mask_for(int bci, InterpreterOopMap* mask) {
 217   methodHandle h_this(Thread::current(), this);
 218   // Only GC uses the OopMapCache during thread stack root scanning
 219   // any other uses generate an oopmap but do not save it in the cache.
 220   if (Universe::heap()->is_gc_active()) {
 221     method_holder()->mask_for(h_this, bci, mask);
 222   } else {
 223     OopMapCache::compute_one_oop_map(h_this, bci, mask);
 224   }
 225   return;
 226 }
 227 
 228 
 229 int Method::bci_from(address bcp) const {
 230   if (is_native() && bcp == 0) {
 231     return 0;
 232   }
 233 #ifdef ASSERT
 234   {
 235     ResourceMark rm;
 236     assert(is_native() && bcp == code_base() || contains(bcp) || VMError::is_error_reported(),
 237            "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
 238            p2i(bcp), name_and_sig_as_C_string());
 239   }
 240 #endif
 241   return bcp - code_base();
 242 }
 243 
 244 
 245 int Method::validate_bci(int bci) const {
 246   return (bci == 0 || bci < code_size()) ? bci : -1;
 247 }
 248 
 249 // Return bci if it appears to be a valid bcp
 250 // Return -1 otherwise.
 251 // Used by profiling code, when invalid data is a possibility.
 252 // The caller is responsible for validating the Method* itself.
 253 int Method::validate_bci_from_bcp(address bcp) const {
 254   // keep bci as -1 if not a valid bci
 255   int bci = -1;
 256   if (bcp == 0 || bcp == code_base()) {
 257     // code_size() may return 0 and we allow 0 here
 258     // the method may be native
 259     bci = 0;
 260   } else if (contains(bcp)) {
 261     bci = bcp - code_base();
 262   }
 263   // Assert that if we have dodged any asserts, bci is negative.
 264   assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
 265   return bci;
 266 }
 267 
 268 address Method::bcp_from(int bci) const {
 269   assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
 270          "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
 271   address bcp = code_base() + bci;
 272   assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
 273   return bcp;
 274 }
 275 
 276 address Method::bcp_from(address bcp) const {
 277   if (is_native() && bcp == NULL) {
 278     return code_base();
 279   } else {
 280     return bcp;
 281   }
 282 }
 283 
 284 int Method::size(bool is_native) {
 285   // If native, then include pointers for native_function and signature_handler
 286   int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
 287   int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
 288   return align_metadata_size(header_size() + extra_words);
 289 }
 290 
 291 
 292 Symbol* Method::klass_name() const {
 293   return method_holder()->name();
 294 }
 295 
 296 
 297 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
 298   log_trace(cds)("Iter(Method): %p", this);
 299 
 300   it->push(&_constMethod);
 301   it->push(&_method_data);
 302   it->push(&_method_counters);
 303 }
 304 
 305 // Attempt to return method oop to original state.  Clear any pointers
 306 // (to objects outside the shared spaces).  We won't be able to predict
 307 // where they should point in a new JVM.  Further initialize some
 308 // entries now in order allow them to be write protected later.
 309 
 310 void Method::remove_unshareable_info() {
 311   unlink_method();
 312 }
 313 
 314 void Method::set_vtable_index(int index) {
 315   if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
 316     // At runtime initialize_vtable is rerun as part of link_class_impl()
 317     // for a shared class loaded by the non-boot loader to obtain the loader
 318     // constraints based on the runtime classloaders' context.
 319     return; // don't write into the shared class
 320   } else {
 321     _vtable_index = index;
 322   }
 323 }
 324 
 325 void Method::set_itable_index(int index) {
 326   if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
 327     // At runtime initialize_itable is rerun as part of link_class_impl()
 328     // for a shared class loaded by the non-boot loader to obtain the loader
 329     // constraints based on the runtime classloaders' context. The dumptime
 330     // itable index should be the same as the runtime index.
 331     assert(_vtable_index == itable_index_max - index,
 332            "archived itable index is different from runtime index");
 333     return; // don’t write into the shared class
 334   } else {
 335     _vtable_index = itable_index_max - index;
 336   }
 337   assert(valid_itable_index(), "");
 338 }
 339 
 340 
 341 
 342 bool Method::was_executed_more_than(int n) {
 343   // Invocation counter is reset when the Method* is compiled.
 344   // If the method has compiled code we therefore assume it has
 345   // be excuted more than n times.
 346   if (is_accessor() || is_empty_method() || (code() != NULL)) {
 347     // interpreter doesn't bump invocation counter of trivial methods
 348     // compiler does not bump invocation counter of compiled methods
 349     return true;
 350   }
 351   else if ((method_counters() != NULL &&
 352             method_counters()->invocation_counter()->carry()) ||
 353            (method_data() != NULL &&
 354             method_data()->invocation_counter()->carry())) {
 355     // The carry bit is set when the counter overflows and causes
 356     // a compilation to occur.  We don't know how many times
 357     // the counter has been reset, so we simply assume it has
 358     // been executed more than n times.
 359     return true;
 360   } else {
 361     return invocation_count() > n;
 362   }
 363 }
 364 
 365 void Method::print_invocation_count() {
 366   if (is_static()) tty->print("static ");
 367   if (is_final()) tty->print("final ");
 368   if (is_synchronized()) tty->print("synchronized ");
 369   if (is_native()) tty->print("native ");
 370   tty->print("%s::", method_holder()->external_name());
 371   name()->print_symbol_on(tty);
 372   signature()->print_symbol_on(tty);
 373 
 374   if (WizardMode) {
 375     // dump the size of the byte codes
 376     tty->print(" {%d}", code_size());
 377   }
 378   tty->cr();
 379 
 380   tty->print_cr ("  interpreter_invocation_count: %8d ", interpreter_invocation_count());
 381   tty->print_cr ("  invocation_counter:           %8d ", invocation_count());
 382   tty->print_cr ("  backedge_counter:             %8d ", backedge_count());
 383 #ifndef PRODUCT
 384   if (CountCompiledCalls) {
 385     tty->print_cr ("  compiled_invocation_count: %8d ", compiled_invocation_count());
 386   }
 387 #endif
 388 }
 389 
 390 // Build a MethodData* object to hold information about this method
 391 // collected in the interpreter.
 392 void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) {
 393   // Do not profile the method if metaspace has hit an OOM previously
 394   // allocating profiling data. Callers clear pending exception so don't
 395   // add one here.
 396   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 397     return;
 398   }
 399 
 400   // Grab a lock here to prevent multiple
 401   // MethodData*s from being created.
 402   MutexLocker ml(MethodData_lock, THREAD);
 403   if (method->method_data() == NULL) {
 404     ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
 405     MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
 406     if (HAS_PENDING_EXCEPTION) {
 407       CompileBroker::log_metaspace_failure();
 408       ClassLoaderDataGraph::set_metaspace_oom(true);
 409       return;   // return the exception (which is cleared)
 410     }
 411 
 412     method->set_method_data(method_data);
 413     if (PrintMethodData && (Verbose || WizardMode)) {
 414       ResourceMark rm(THREAD);
 415       tty->print("build_interpreter_method_data for ");
 416       method->print_name(tty);
 417       tty->cr();
 418       // At the end of the run, the MDO, full of data, will be dumped.
 419     }
 420   }
 421 }
 422 
 423 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
 424   // Do not profile the method if metaspace has hit an OOM previously
 425   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 426     return NULL;
 427   }
 428 
 429   methodHandle mh(m);
 430   MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
 431   if (HAS_PENDING_EXCEPTION) {
 432     CompileBroker::log_metaspace_failure();
 433     ClassLoaderDataGraph::set_metaspace_oom(true);
 434     return NULL;   // return the exception (which is cleared)
 435   }
 436   if (!mh->init_method_counters(counters)) {
 437     MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
 438   }
 439 
 440   if (LogTouchedMethods) {
 441     mh->log_touched(CHECK_NULL);
 442   }
 443 
 444   return mh->method_counters();
 445 }
 446 
 447 bool Method::init_method_counters(MethodCounters* counters) {
 448   // Try to install a pointer to MethodCounters, return true on success.
 449   return Atomic::replace_if_null(counters, &_method_counters);
 450 }
 451 
 452 void Method::cleanup_inline_caches() {
 453   // The current system doesn't use inline caches in the interpreter
 454   // => nothing to do (keep this method around for future use)
 455 }
 456 
 457 
 458 int Method::extra_stack_words() {
 459   // not an inline function, to avoid a header dependency on Interpreter
 460   return extra_stack_entries() * Interpreter::stackElementSize;
 461 }
 462 
 463 
 464 void Method::compute_size_of_parameters(Thread *thread) {
 465   ArgumentSizeComputer asc(signature());
 466   set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
 467 }
 468 
 469 BasicType Method::result_type() const {
 470   ResultTypeFinder rtf(signature());
 471   return rtf.type();
 472 }
 473 
 474 
 475 bool Method::is_empty_method() const {
 476   return  code_size() == 1
 477       && *code_base() == Bytecodes::_return;
 478 }
 479 
 480 
 481 bool Method::is_vanilla_constructor() const {
 482   // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
 483   // which only calls the superclass vanilla constructor and possibly does stores of
 484   // zero constants to local fields:
 485   //
 486   //   aload_0
 487   //   invokespecial
 488   //   indexbyte1
 489   //   indexbyte2
 490   //
 491   // followed by an (optional) sequence of:
 492   //
 493   //   aload_0
 494   //   aconst_null / iconst_0 / fconst_0 / dconst_0
 495   //   putfield
 496   //   indexbyte1
 497   //   indexbyte2
 498   //
 499   // followed by:
 500   //
 501   //   return
 502 
 503   assert(name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructors");
 504   assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
 505   int size = code_size();
 506   // Check if size match
 507   if (size == 0 || size % 5 != 0) return false;
 508   address cb = code_base();
 509   int last = size - 1;
 510   if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
 511     // Does not call superclass default constructor
 512     return false;
 513   }
 514   // Check optional sequence
 515   for (int i = 4; i < last; i += 5) {
 516     if (cb[i] != Bytecodes::_aload_0) return false;
 517     if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
 518     if (cb[i+2] != Bytecodes::_putfield) return false;
 519   }
 520   return true;
 521 }
 522 
 523 
 524 bool Method::compute_has_loops_flag() {
 525   BytecodeStream bcs(this);
 526   Bytecodes::Code bc;
 527 
 528   while ((bc = bcs.next()) >= 0) {
 529     switch( bc ) {
 530       case Bytecodes::_ifeq:
 531       case Bytecodes::_ifnull:
 532       case Bytecodes::_iflt:
 533       case Bytecodes::_ifle:
 534       case Bytecodes::_ifne:
 535       case Bytecodes::_ifnonnull:
 536       case Bytecodes::_ifgt:
 537       case Bytecodes::_ifge:
 538       case Bytecodes::_if_icmpeq:
 539       case Bytecodes::_if_icmpne:
 540       case Bytecodes::_if_icmplt:
 541       case Bytecodes::_if_icmpgt:
 542       case Bytecodes::_if_icmple:
 543       case Bytecodes::_if_icmpge:
 544       case Bytecodes::_if_acmpeq:
 545       case Bytecodes::_if_acmpne:
 546       case Bytecodes::_goto:
 547       case Bytecodes::_jsr:
 548         if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
 549         break;
 550 
 551       case Bytecodes::_goto_w:
 552       case Bytecodes::_jsr_w:
 553         if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
 554         break;
 555 
 556       default:
 557         break;
 558     }
 559   }
 560   _access_flags.set_loops_flag_init();
 561   return _access_flags.has_loops();
 562 }
 563 
 564 bool Method::is_final_method(AccessFlags class_access_flags) const {
 565   // or "does_not_require_vtable_entry"
 566   // default method or overpass can occur, is not final (reuses vtable entry)
 567   // private methods in classes get vtable entries for backward class compatibility.
 568   if (is_overpass() || is_default_method())  return false;
 569   return is_final() || class_access_flags.is_final();
 570 }
 571 
 572 bool Method::is_final_method() const {
 573   return is_final_method(method_holder()->access_flags());
 574 }
 575 
 576 bool Method::is_default_method() const {
 577   if (method_holder() != NULL &&
 578       method_holder()->is_interface() &&
 579       !is_abstract() && !is_private()) {
 580     return true;
 581   } else {
 582     return false;
 583   }
 584 }
 585 
 586 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
 587   if (is_final_method(class_access_flags))  return true;
 588 #ifdef ASSERT
 589   ResourceMark rm;
 590   bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
 591   if (class_access_flags.is_interface()) {
 592       assert(is_nonv == is_static() || is_nonv == is_private(),
 593              "nonvirtual unexpected for non-static, non-private: %s",
 594              name_and_sig_as_C_string());
 595   }
 596 #endif
 597   assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
 598   return vtable_index() == nonvirtual_vtable_index;
 599 }
 600 
 601 bool Method::can_be_statically_bound() const {
 602   return can_be_statically_bound(method_holder()->access_flags());
 603 }
 604 
 605 bool Method::is_accessor() const {
 606   return is_getter() || is_setter();
 607 }
 608 
 609 bool Method::is_getter() const {
 610   if (code_size() != 5) return false;
 611   if (size_of_parameters() != 1) return false;
 612   if (java_code_at(0) != Bytecodes::_aload_0)  return false;
 613   if (java_code_at(1) != Bytecodes::_getfield) return false;
 614   switch (java_code_at(4)) {
 615     case Bytecodes::_ireturn:
 616     case Bytecodes::_lreturn:
 617     case Bytecodes::_freturn:
 618     case Bytecodes::_dreturn:
 619     case Bytecodes::_areturn:
 620       break;
 621     default:
 622       return false;
 623   }
 624   return true;
 625 }
 626 
 627 bool Method::is_setter() const {
 628   if (code_size() != 6) return false;
 629   if (java_code_at(0) != Bytecodes::_aload_0) return false;
 630   switch (java_code_at(1)) {
 631     case Bytecodes::_iload_1:
 632     case Bytecodes::_aload_1:
 633     case Bytecodes::_fload_1:
 634       if (size_of_parameters() != 2) return false;
 635       break;
 636     case Bytecodes::_dload_1:
 637     case Bytecodes::_lload_1:
 638       if (size_of_parameters() != 3) return false;
 639       break;
 640     default:
 641       return false;
 642   }
 643   if (java_code_at(2) != Bytecodes::_putfield) return false;
 644   if (java_code_at(5) != Bytecodes::_return)   return false;
 645   return true;
 646 }
 647 
 648 bool Method::is_constant_getter() const {
 649   int last_index = code_size() - 1;
 650   // Check if the first 1-3 bytecodes are a constant push
 651   // and the last bytecode is a return.
 652   return (2 <= code_size() && code_size() <= 4 &&
 653           Bytecodes::is_const(java_code_at(0)) &&
 654           Bytecodes::length_for(java_code_at(0)) == last_index &&
 655           Bytecodes::is_return(java_code_at(last_index)));
 656 }
 657 
 658 bool Method::is_initializer() const {
 659   return is_object_initializer() || is_static_initializer();
 660 }
 661 
 662 bool Method::has_valid_initializer_flags() const {
 663   return (is_static() ||
 664           method_holder()->major_version() < 51);
 665 }
 666 
 667 bool Method::is_static_initializer() const {
 668   // For classfiles version 51 or greater, ensure that the clinit method is
 669   // static.  Non-static methods with the name "<clinit>" are not static
 670   // initializers. (older classfiles exempted for backward compatibility)
 671   return name() == vmSymbols::class_initializer_name() &&
 672          has_valid_initializer_flags();
 673 }
 674 
 675 bool Method::is_object_initializer() const {
 676    return name() == vmSymbols::object_initializer_name();
 677 }
 678 
 679 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
 680   int length = method->checked_exceptions_length();
 681   if (length == 0) {  // common case
 682     return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
 683   } else {
 684     methodHandle h_this(THREAD, method);
 685     objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
 686     objArrayHandle mirrors (THREAD, m_oop);
 687     for (int i = 0; i < length; i++) {
 688       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
 689       Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
 690       assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
 691       mirrors->obj_at_put(i, k->java_mirror());
 692     }
 693     return mirrors;
 694   }
 695 };
 696 
 697 
 698 int Method::line_number_from_bci(int bci) const {
 699   if (bci == SynchronizationEntryBCI) bci = 0;
 700   assert(bci == 0 || 0 <= bci && bci < code_size(), "illegal bci");
 701   int best_bci  =  0;
 702   int best_line = -1;
 703 
 704   if (has_linenumber_table()) {
 705     // The line numbers are a short array of 2-tuples [start_pc, line_number].
 706     // Not necessarily sorted and not necessarily one-to-one.
 707     CompressedLineNumberReadStream stream(compressed_linenumber_table());
 708     while (stream.read_pair()) {
 709       if (stream.bci() == bci) {
 710         // perfect match
 711         return stream.line();
 712       } else {
 713         // update best_bci/line
 714         if (stream.bci() < bci && stream.bci() >= best_bci) {
 715           best_bci  = stream.bci();
 716           best_line = stream.line();
 717         }
 718       }
 719     }
 720   }
 721   return best_line;
 722 }
 723 
 724 
 725 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
 726   if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
 727     Thread *thread = Thread::current();
 728     Symbol* klass_name = constants()->klass_name_at(klass_index);
 729     Handle loader(thread, method_holder()->class_loader());
 730     Handle prot  (thread, method_holder()->protection_domain());
 731     return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
 732   } else {
 733     return true;
 734   }
 735 }
 736 
 737 
 738 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
 739   int klass_index = constants()->klass_ref_index_at(refinfo_index);
 740   if (must_be_resolved) {
 741     // Make sure klass is resolved in constantpool.
 742     if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
 743   }
 744   return is_klass_loaded_by_klass_index(klass_index);
 745 }
 746 
 747 
 748 void Method::set_native_function(address function, bool post_event_flag) {
 749   assert(function != NULL, "use clear_native_function to unregister natives");
 750   assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
 751   address* native_function = native_function_addr();
 752 
 753   // We can see racers trying to place the same native function into place. Once
 754   // is plenty.
 755   address current = *native_function;
 756   if (current == function) return;
 757   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
 758       function != NULL) {
 759     // native_method_throw_unsatisfied_link_error_entry() should only
 760     // be passed when post_event_flag is false.
 761     assert(function !=
 762       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 763       "post_event_flag mis-match");
 764 
 765     // post the bind event, and possible change the bind function
 766     JvmtiExport::post_native_method_bind(this, &function);
 767   }
 768   *native_function = function;
 769   // This function can be called more than once. We must make sure that we always
 770   // use the latest registered method -> check if a stub already has been generated.
 771   // If so, we have to make it not_entrant.
 772   CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates
 773   if (nm != NULL) {
 774     nm->make_not_entrant();
 775   }
 776 }
 777 
 778 
 779 bool Method::has_native_function() const {
 780   if (is_method_handle_intrinsic())
 781     return false;  // special-cased in SharedRuntime::generate_native_wrapper
 782   address func = native_function();
 783   return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
 784 }
 785 
 786 
 787 void Method::clear_native_function() {
 788   // Note: is_method_handle_intrinsic() is allowed here.
 789   set_native_function(
 790     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 791     !native_bind_event_is_interesting);
 792   clear_code();
 793 }
 794 
 795 address Method::critical_native_function() {
 796   methodHandle mh(this);
 797   return NativeLookup::lookup_critical_entry(mh);
 798 }
 799 
 800 
 801 void Method::set_signature_handler(address handler) {
 802   address* signature_handler =  signature_handler_addr();
 803   *signature_handler = handler;
 804 }
 805 
 806 
 807 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
 808   if (PrintCompilation && report) {
 809     ttyLocker ttyl;
 810     tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
 811     if (comp_level == CompLevel_all) {
 812       tty->print("all levels ");
 813     } else {
 814       tty->print("levels ");
 815       for (int i = (int)CompLevel_none; i <= comp_level; i++) {
 816         tty->print("%d ", i);
 817       }
 818     }
 819     this->print_short_name(tty);
 820     int size = this->code_size();
 821     if (size > 0) {
 822       tty->print(" (%d bytes)", size);
 823     }
 824     if (reason != NULL) {
 825       tty->print("   %s", reason);
 826     }
 827     tty->cr();
 828   }
 829   if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
 830     ttyLocker ttyl;
 831     xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
 832                      os::current_thread_id(), is_osr, comp_level);
 833     if (reason != NULL) {
 834       xtty->print(" reason=\'%s\'", reason);
 835     }
 836     xtty->method(this);
 837     xtty->stamp();
 838     xtty->end_elem();
 839   }
 840 }
 841 
 842 bool Method::is_always_compilable() const {
 843   // Generated adapters must be compiled
 844   if (is_method_handle_intrinsic() && is_synthetic()) {
 845     assert(!is_not_c1_compilable(), "sanity check");
 846     assert(!is_not_c2_compilable(), "sanity check");
 847     return true;
 848   }
 849 
 850   return false;
 851 }
 852 
 853 bool Method::is_not_compilable(int comp_level) const {
 854   if (number_of_breakpoints() > 0)
 855     return true;
 856   if (is_always_compilable())
 857     return false;
 858   if (comp_level == CompLevel_any)
 859     return is_not_c1_compilable() || is_not_c2_compilable();
 860   if (is_c1_compile(comp_level))
 861     return is_not_c1_compilable();
 862   if (is_c2_compile(comp_level))
 863     return is_not_c2_compilable();
 864   return false;
 865 }
 866 
 867 // call this when compiler finds that this method is not compilable
 868 void Method::set_not_compilable(int comp_level, bool report, const char* reason) {
 869   if (is_always_compilable()) {
 870     // Don't mark a method which should be always compilable
 871     return;
 872   }
 873   print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
 874   if (comp_level == CompLevel_all) {
 875     set_not_c1_compilable();
 876     set_not_c2_compilable();
 877   } else {
 878     if (is_c1_compile(comp_level))
 879       set_not_c1_compilable();
 880     if (is_c2_compile(comp_level))
 881       set_not_c2_compilable();
 882   }
 883   CompilationPolicy::policy()->disable_compilation(this);
 884   assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
 885 }
 886 
 887 bool Method::is_not_osr_compilable(int comp_level) const {
 888   if (is_not_compilable(comp_level))
 889     return true;
 890   if (comp_level == CompLevel_any)
 891     return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
 892   if (is_c1_compile(comp_level))
 893     return is_not_c1_osr_compilable();
 894   if (is_c2_compile(comp_level))
 895     return is_not_c2_osr_compilable();
 896   return false;
 897 }
 898 
 899 void Method::set_not_osr_compilable(int comp_level, bool report, const char* reason) {
 900   print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
 901   if (comp_level == CompLevel_all) {
 902     set_not_c1_osr_compilable();
 903     set_not_c2_osr_compilable();
 904   } else {
 905     if (is_c1_compile(comp_level))
 906       set_not_c1_osr_compilable();
 907     if (is_c2_compile(comp_level))
 908       set_not_c2_osr_compilable();
 909   }
 910   CompilationPolicy::policy()->disable_compilation(this);
 911   assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
 912 }
 913 
 914 // Revert to using the interpreter and clear out the nmethod
 915 void Method::clear_code(bool acquire_lock /* = true */) {
 916   MutexLockerEx pl(acquire_lock ? Patching_lock : NULL, Mutex::_no_safepoint_check_flag);
 917   // this may be NULL if c2i adapters have not been made yet
 918   // Only should happen at allocate time.
 919   if (adapter() == NULL) {
 920     _from_compiled_entry    = NULL;
 921   } else {
 922     _from_compiled_entry    = adapter()->get_c2i_entry();
 923   }
 924   OrderAccess::storestore();
 925   _from_interpreted_entry = _i2i_entry;
 926   OrderAccess::storestore();
 927   _code = NULL;
 928 }
 929 
 930 #if INCLUDE_CDS
 931 // Called by class data sharing to remove any entry points (which are not shared)
 932 void Method::unlink_method() {
 933   _code = NULL;
 934 
 935   assert(DumpSharedSpaces, "dump time only");
 936   // Set the values to what they should be at run time. Note that
 937   // this Method can no longer be executed during dump time.
 938   _i2i_entry = Interpreter::entry_for_cds_method(this);
 939   _from_interpreted_entry = _i2i_entry;
 940 
 941   if (is_native()) {
 942     *native_function_addr() = NULL;
 943     set_signature_handler(NULL);
 944   }
 945   NOT_PRODUCT(set_compiled_invocation_count(0);)
 946 
 947   CDSAdapterHandlerEntry* cds_adapter = (CDSAdapterHandlerEntry*)adapter();
 948   constMethod()->set_adapter_trampoline(cds_adapter->get_adapter_trampoline());
 949   _from_compiled_entry = cds_adapter->get_c2i_entry_trampoline();
 950   assert(*((int*)_from_compiled_entry) == 0, "must be NULL during dump time, to be initialized at run time");
 951 
 952   set_method_data(NULL);
 953   clear_method_counters();
 954 }
 955 #endif
 956 
 957 /****************************************************************************
 958 // The following illustrates how the entries work for CDS shared Methods:
 959 //
 960 // Our goal is to delay writing into a shared Method until it's compiled.
 961 // Hence, we want to determine the initial values for _i2i_entry,
 962 // _from_interpreted_entry and _from_compiled_entry during CDS dump time.
 963 //
 964 // In this example, both Methods A and B have the _i2i_entry of "zero_locals".
 965 // They also have similar signatures so that they will share the same
 966 // AdapterHandlerEntry.
 967 //
 968 // _adapter_trampoline points to a fixed location in the RW section of
 969 // the CDS archive. This location initially contains a NULL pointer. When the
 970 // first of method A or B is linked, an AdapterHandlerEntry is allocated
 971 // dynamically, and its c2i/i2c entries are generated.
 972 //
 973 // _i2i_entry and _from_interpreted_entry initially points to the same
 974 // (fixed) location in the CODE section of the CDS archive. This contains
 975 // an unconditional branch to the actual entry for "zero_locals", which is
 976 // generated at run time and may be on an arbitrary address. Thus, the
 977 // unconditional branch is also generated at run time to jump to the correct
 978 // address.
 979 //
 980 // Similarly, _from_compiled_entry points to a fixed address in the CODE
 981 // section. This address has enough space for an unconditional branch
 982 // instruction, and is initially zero-filled. After the AdapterHandlerEntry is
 983 // initialized, and the address for the actual c2i_entry is known, we emit a
 984 // branch instruction here to branch to the actual c2i_entry.
 985 //
 986 // The effect of the extra branch on the i2i and c2i entries is negligible.
 987 //
 988 // The reason for putting _adapter_trampoline in RO is many shared Methods
 989 // share the same AdapterHandlerEntry, so we can save space in the RW section
 990 // by having the extra indirection.
 991 
 992 
 993 [Method A: RW]
 994   _constMethod ----> [ConstMethod: RO]
 995                        _adapter_trampoline -----------+
 996                                                       |
 997   _i2i_entry              (same value as method B)    |
 998   _from_interpreted_entry (same value as method B)    |
 999   _from_compiled_entry    (same value as method B)    |
1000                                                       |
1001                                                       |
1002 [Method B: RW]                               +--------+
1003   _constMethod ----> [ConstMethod: RO]       |
1004                        _adapter_trampoline --+--->(AdapterHandlerEntry* ptr: RW)-+
1005                                                                                  |
1006                                                  +-------------------------------+
1007                                                  |
1008                                                  +----> [AdapterHandlerEntry] (allocated at run time)
1009                                                               _fingerprint
1010                                                               _c2i_entry ---------------------------------+->[c2i entry..]
1011  _i2i_entry  -------------+                                   _i2c_entry ---------------+-> [i2c entry..] |
1012  _from_interpreted_entry  |                                   _c2i_unverified_entry     |                 |
1013          |                |                                                             |                 |
1014          |                |  (_cds_entry_table: CODE)                                   |                 |
1015          |                +->[0]: jmp _entry_table[0] --> (i2i_entry_for "zero_locals") |                 |
1016          |                |                               (allocated at run time)       |                 |
1017          |                |  ...                           [asm code ...]               |                 |
1018          +-[not compiled]-+  [n]: jmp _entry_table[n]                                   |                 |
1019          |                                                                              |                 |
1020          |                                                                              |                 |
1021          +-[compiled]-------------------------------------------------------------------+                 |
1022                                                                                                           |
1023  _from_compiled_entry------------>  (_c2i_entry_trampoline: CODE)                                         |
1024                                     [jmp c2i_entry] ------------------------------------------------------+
1025 
1026 ***/
1027 
1028 // Called when the method_holder is getting linked. Setup entrypoints so the method
1029 // is ready to be called from interpreter, compiler, and vtables.
1030 void Method::link_method(const methodHandle& h_method, TRAPS) {
1031   // If the code cache is full, we may reenter this function for the
1032   // leftover methods that weren't linked.
1033   if (is_shared()) {
1034     address entry = Interpreter::entry_for_cds_method(h_method);
1035     assert(entry != NULL && entry == _i2i_entry,
1036            "should be correctly set during dump time");
1037     if (adapter() != NULL) {
1038       return;
1039     }
1040     assert(entry == _from_interpreted_entry,
1041            "should be correctly set during dump time");
1042   } else if (_i2i_entry != NULL) {
1043     return;
1044   }
1045   assert( _code == NULL, "nothing compiled yet" );
1046 
1047   // Setup interpreter entrypoint
1048   assert(this == h_method(), "wrong h_method()" );
1049 
1050   if (!is_shared()) {
1051     assert(adapter() == NULL, "init'd to NULL");
1052     address entry = Interpreter::entry_for_method(h_method);
1053     assert(entry != NULL, "interpreter entry must be non-null");
1054     // Sets both _i2i_entry and _from_interpreted_entry
1055     set_interpreter_entry(entry);
1056   }
1057 
1058   // Don't overwrite already registered native entries.
1059   if (is_native() && !has_native_function()) {
1060     set_native_function(
1061       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1062       !native_bind_event_is_interesting);
1063   }
1064 
1065   // Setup compiler entrypoint.  This is made eagerly, so we do not need
1066   // special handling of vtables.  An alternative is to make adapters more
1067   // lazily by calling make_adapter() from from_compiled_entry() for the
1068   // normal calls.  For vtable calls life gets more complicated.  When a
1069   // call-site goes mega-morphic we need adapters in all methods which can be
1070   // called from the vtable.  We need adapters on such methods that get loaded
1071   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
1072   // problem we'll make these lazily later.
1073   (void) make_adapters(h_method, CHECK);
1074 
1075   // ONLY USE the h_method now as make_adapter may have blocked
1076 
1077 }
1078 
1079 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1080   // Adapters for compiled code are made eagerly here.  They are fairly
1081   // small (generally < 100 bytes) and quick to make (and cached and shared)
1082   // so making them eagerly shouldn't be too expensive.
1083   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1084   if (adapter == NULL ) {
1085     if (!is_init_completed()) {
1086       // Don't throw exceptions during VM initialization because java.lang.* classes
1087       // might not have been initialized, causing problems when constructing the
1088       // Java exception object.
1089       vm_exit_during_initialization("Out of space in CodeCache for adapters");
1090     } else {
1091       THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
1092     }
1093   }
1094 
1095   if (mh->is_shared()) {
1096     assert(mh->adapter() == adapter, "must be");
1097     assert(mh->_from_compiled_entry != NULL, "must be");
1098   } else {
1099     mh->set_adapter_entry(adapter);
1100     mh->_from_compiled_entry = adapter->get_c2i_entry();
1101   }
1102   return adapter->get_c2i_entry();
1103 }
1104 
1105 void Method::restore_unshareable_info(TRAPS) {
1106   assert(is_method() && is_valid_method(), "ensure C++ vtable is restored");
1107 
1108   // Since restore_unshareable_info can be called more than once for a method, don't
1109   // redo any work.
1110   if (adapter() == NULL) {
1111     methodHandle mh(THREAD, this);
1112     link_method(mh, CHECK);
1113   }
1114 }
1115 
1116 address Method::from_compiled_entry_no_trampoline() const {
1117   CompiledMethod *code = OrderAccess::load_acquire(&_code);
1118   if (code) {
1119     return code->verified_entry_point();
1120   } else {
1121     return adapter()->get_c2i_entry();
1122   }
1123 }
1124 
1125 // The verified_code_entry() must be called when a invoke is resolved
1126 // on this method.
1127 
1128 // It returns the compiled code entry point, after asserting not null.
1129 // This function is called after potential safepoints so that nmethod
1130 // or adapter that it points to is still live and valid.
1131 // This function must not hit a safepoint!
1132 address Method::verified_code_entry() {
1133   debug_only(NoSafepointVerifier nsv;)
1134   assert(_from_compiled_entry != NULL, "must be set");
1135   return _from_compiled_entry;
1136 }
1137 
1138 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1139 // (could be racing a deopt).
1140 // Not inline to avoid circular ref.
1141 bool Method::check_code() const {
1142   // cached in a register or local.  There's a race on the value of the field.
1143   CompiledMethod *code = OrderAccess::load_acquire(&_code);
1144   return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
1145 }
1146 
1147 // Install compiled code.  Instantly it can execute.
1148 void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
1149   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1150   assert( code, "use clear_code to remove code" );
1151   assert( mh->check_code(), "" );
1152 
1153   guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
1154 
1155   // These writes must happen in this order, because the interpreter will
1156   // directly jump to from_interpreted_entry which jumps to an i2c adapter
1157   // which jumps to _from_compiled_entry.
1158   mh->_code = code;             // Assign before allowing compiled code to exec
1159 
1160   int comp_level = code->comp_level();
1161   // In theory there could be a race here. In practice it is unlikely
1162   // and not worth worrying about.
1163   if (comp_level > mh->highest_comp_level()) {
1164     mh->set_highest_comp_level(comp_level);
1165   }
1166 
1167   OrderAccess::storestore();
1168   mh->_from_compiled_entry = code->verified_entry_point();
1169   OrderAccess::storestore();
1170   // Instantly compiled code can execute.
1171   if (!mh->is_method_handle_intrinsic())
1172     mh->_from_interpreted_entry = mh->get_i2c_entry();
1173 }
1174 
1175 
1176 bool Method::is_overridden_in(Klass* k) const {
1177   InstanceKlass* ik = InstanceKlass::cast(k);
1178 
1179   if (ik->is_interface()) return false;
1180 
1181   // If method is an interface, we skip it - except if it
1182   // is a miranda method
1183   if (method_holder()->is_interface()) {
1184     // Check that method is not a miranda method
1185     if (ik->lookup_method(name(), signature()) == NULL) {
1186       // No implementation exist - so miranda method
1187       return false;
1188     }
1189     return true;
1190   }
1191 
1192   assert(ik->is_subclass_of(method_holder()), "should be subklass");
1193   if (!has_vtable_index()) {
1194     return false;
1195   } else {
1196     Method* vt_m = ik->method_at_vtable(vtable_index());
1197     return vt_m != this;
1198   }
1199 }
1200 
1201 
1202 // give advice about whether this Method* should be cached or not
1203 bool Method::should_not_be_cached() const {
1204   if (is_old()) {
1205     // This method has been redefined. It is either EMCP or obsolete
1206     // and we don't want to cache it because that would pin the method
1207     // down and prevent it from being collectible if and when it
1208     // finishes executing.
1209     return true;
1210   }
1211 
1212   // caching this method should be just fine
1213   return false;
1214 }
1215 
1216 
1217 /**
1218  *  Returns true if this is one of the specially treated methods for
1219  *  security related stack walks (like Reflection.getCallerClass).
1220  */
1221 bool Method::is_ignored_by_security_stack_walk() const {
1222   if (intrinsic_id() == vmIntrinsics::_invoke) {
1223     // This is Method.invoke() -- ignore it
1224     return true;
1225   }
1226   if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1227     // This is an auxilary frame -- ignore it
1228     return true;
1229   }
1230   if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1231     // This is an internal adapter frame for method handles -- ignore it
1232     return true;
1233   }
1234   return false;
1235 }
1236 
1237 
1238 // Constant pool structure for invoke methods:
1239 enum {
1240   _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.
1241   _imcp_invoke_signature,       // utf8: (variable Symbol*)
1242   _imcp_limit
1243 };
1244 
1245 // Test if this method is an MH adapter frame generated by Java code.
1246 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1247 bool Method::is_compiled_lambda_form() const {
1248   return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1249 }
1250 
1251 // Test if this method is an internal MH primitive method.
1252 bool Method::is_method_handle_intrinsic() const {
1253   vmIntrinsics::ID iid = intrinsic_id();
1254   return (MethodHandles::is_signature_polymorphic(iid) &&
1255           MethodHandles::is_signature_polymorphic_intrinsic(iid));
1256 }
1257 
1258 bool Method::has_member_arg() const {
1259   vmIntrinsics::ID iid = intrinsic_id();
1260   return (MethodHandles::is_signature_polymorphic(iid) &&
1261           MethodHandles::has_member_arg(iid));
1262 }
1263 
1264 // Make an instance of a signature-polymorphic internal MH primitive.
1265 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1266                                                          Symbol* signature,
1267                                                          TRAPS) {
1268   ResourceMark rm;
1269   methodHandle empty;
1270 
1271   InstanceKlass* holder = SystemDictionary::MethodHandle_klass();
1272   Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1273   assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1274   if (TraceMethodHandles) {
1275     tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1276   }
1277 
1278   // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1279   name->increment_refcount();
1280   signature->increment_refcount();
1281 
1282   int cp_length = _imcp_limit;
1283   ClassLoaderData* loader_data = holder->class_loader_data();
1284   constantPoolHandle cp;
1285   {
1286     ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1287     cp = constantPoolHandle(THREAD, cp_oop);
1288   }
1289   cp->set_pool_holder(holder);
1290   cp->symbol_at_put(_imcp_invoke_name,       name);
1291   cp->symbol_at_put(_imcp_invoke_signature,  signature);
1292   cp->set_has_preresolution();
1293 
1294   // decide on access bits:  public or not?
1295   int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1296   bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1297   if (must_be_static)  flags_bits |= JVM_ACC_STATIC;
1298   assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1299 
1300   methodHandle m;
1301   {
1302     InlineTableSizes sizes;
1303     Method* m_oop = Method::allocate(loader_data, 0,
1304                                      accessFlags_from(flags_bits), &sizes,
1305                                      ConstMethod::NORMAL, CHECK_(empty));
1306     m = methodHandle(THREAD, m_oop);
1307   }
1308   m->set_constants(cp());
1309   m->set_name_index(_imcp_invoke_name);
1310   m->set_signature_index(_imcp_invoke_signature);
1311   assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1312   assert(m->signature() == signature, "");
1313   ResultTypeFinder rtf(signature);
1314   m->constMethod()->set_result_type(rtf.type());
1315   m->compute_size_of_parameters(THREAD);
1316   m->init_intrinsic_id();
1317   assert(m->is_method_handle_intrinsic(), "");
1318 #ifdef ASSERT
1319   if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();
1320   assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1321   assert(m->intrinsic_id() == iid, "correctly predicted iid");
1322 #endif //ASSERT
1323 
1324   // Finally, set up its entry points.
1325   assert(m->can_be_statically_bound(), "");
1326   m->set_vtable_index(Method::nonvirtual_vtable_index);
1327   m->link_method(m, CHECK_(empty));
1328 
1329   if (TraceMethodHandles && (Verbose || WizardMode)) {
1330     ttyLocker ttyl;
1331     m->print_on(tty);
1332   }
1333 
1334   return m;
1335 }
1336 
1337 Klass* Method::check_non_bcp_klass(Klass* klass) {
1338   if (klass != NULL && klass->class_loader() != NULL) {
1339     if (klass->is_objArray_klass())
1340       klass = ObjArrayKlass::cast(klass)->bottom_klass();
1341     return klass;
1342   }
1343   return NULL;
1344 }
1345 
1346 
1347 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1348                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1349   // Code below does not work for native methods - they should never get rewritten anyway
1350   assert(!m->is_native(), "cannot rewrite native methods");
1351   // Allocate new Method*
1352   AccessFlags flags = m->access_flags();
1353 
1354   ConstMethod* cm = m->constMethod();
1355   int checked_exceptions_len = cm->checked_exceptions_length();
1356   int localvariable_len = cm->localvariable_table_length();
1357   int exception_table_len = cm->exception_table_length();
1358   int method_parameters_len = cm->method_parameters_length();
1359   int method_annotations_len = cm->method_annotations_length();
1360   int parameter_annotations_len = cm->parameter_annotations_length();
1361   int type_annotations_len = cm->type_annotations_length();
1362   int default_annotations_len = cm->default_annotations_length();
1363 
1364   InlineTableSizes sizes(
1365       localvariable_len,
1366       new_compressed_linenumber_size,
1367       exception_table_len,
1368       checked_exceptions_len,
1369       method_parameters_len,
1370       cm->generic_signature_index(),
1371       method_annotations_len,
1372       parameter_annotations_len,
1373       type_annotations_len,
1374       default_annotations_len,
1375       0);
1376 
1377   ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1378   Method* newm_oop = Method::allocate(loader_data,
1379                                       new_code_length,
1380                                       flags,
1381                                       &sizes,
1382                                       m->method_type(),
1383                                       CHECK_(methodHandle()));
1384   methodHandle newm (THREAD, newm_oop);
1385 
1386   // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1387   ConstMethod* newcm = newm->constMethod();
1388   int new_const_method_size = newm->constMethod()->size();
1389 
1390   // This works because the source and target are both Methods. Some compilers
1391   // (e.g., clang) complain that the target vtable pointer will be stomped,
1392   // so cast away newm()'s and m()'s Methodness.
1393   memcpy((void*)newm(), (void*)m(), sizeof(Method));
1394 
1395   // Create shallow copy of ConstMethod.
1396   memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1397 
1398   // Reset correct method/const method, method size, and parameter info
1399   newm->set_constMethod(newcm);
1400   newm->constMethod()->set_code_size(new_code_length);
1401   newm->constMethod()->set_constMethod_size(new_const_method_size);
1402   assert(newm->code_size() == new_code_length, "check");
1403   assert(newm->method_parameters_length() == method_parameters_len, "check");
1404   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1405   assert(newm->exception_table_length() == exception_table_len, "check");
1406   assert(newm->localvariable_table_length() == localvariable_len, "check");
1407   // Copy new byte codes
1408   memcpy(newm->code_base(), new_code, new_code_length);
1409   // Copy line number table
1410   if (new_compressed_linenumber_size > 0) {
1411     memcpy(newm->compressed_linenumber_table(),
1412            new_compressed_linenumber_table,
1413            new_compressed_linenumber_size);
1414   }
1415   // Copy method_parameters
1416   if (method_parameters_len > 0) {
1417     memcpy(newm->method_parameters_start(),
1418            m->method_parameters_start(),
1419            method_parameters_len * sizeof(MethodParametersElement));
1420   }
1421   // Copy checked_exceptions
1422   if (checked_exceptions_len > 0) {
1423     memcpy(newm->checked_exceptions_start(),
1424            m->checked_exceptions_start(),
1425            checked_exceptions_len * sizeof(CheckedExceptionElement));
1426   }
1427   // Copy exception table
1428   if (exception_table_len > 0) {
1429     memcpy(newm->exception_table_start(),
1430            m->exception_table_start(),
1431            exception_table_len * sizeof(ExceptionTableElement));
1432   }
1433   // Copy local variable number table
1434   if (localvariable_len > 0) {
1435     memcpy(newm->localvariable_table_start(),
1436            m->localvariable_table_start(),
1437            localvariable_len * sizeof(LocalVariableTableElement));
1438   }
1439   // Copy stackmap table
1440   if (m->has_stackmap_table()) {
1441     int code_attribute_length = m->stackmap_data()->length();
1442     Array<u1>* stackmap_data =
1443       MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1444     memcpy((void*)stackmap_data->adr_at(0),
1445            (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1446     newm->set_stackmap_data(stackmap_data);
1447   }
1448 
1449   // copy annotations over to new method
1450   newcm->copy_annotations_from(loader_data, cm, CHECK_NULL);
1451   return newm;
1452 }
1453 
1454 vmSymbols::SID Method::klass_id_for_intrinsics(const Klass* holder) {
1455   // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1456   // because we are not loading from core libraries
1457   // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1458   // which does not use the class default class loader so we check for its loader here
1459   const InstanceKlass* ik = InstanceKlass::cast(holder);
1460   if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1461     return vmSymbols::NO_SID;   // regardless of name, no intrinsics here
1462   }
1463 
1464   // see if the klass name is well-known:
1465   Symbol* klass_name = ik->name();
1466   return vmSymbols::find_sid(klass_name);
1467 }
1468 
1469 void Method::init_intrinsic_id() {
1470   assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1471   const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1472   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1473   assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1474 
1475   // the klass name is well-known:
1476   vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1477   assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1478 
1479   // ditto for method and signature:
1480   vmSymbols::SID  name_id = vmSymbols::find_sid(name());
1481   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1482       && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1483       && name_id == vmSymbols::NO_SID) {
1484     return;
1485   }
1486   vmSymbols::SID   sig_id = vmSymbols::find_sid(signature());
1487   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1488       && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1489       && sig_id == vmSymbols::NO_SID) {
1490     return;
1491   }
1492   jshort flags = access_flags().as_short();
1493 
1494   vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1495   if (id != vmIntrinsics::_none) {
1496     set_intrinsic_id(id);
1497     if (id == vmIntrinsics::_Class_cast) {
1498       // Even if the intrinsic is rejected, we want to inline this simple method.
1499       set_force_inline(true);
1500     }
1501     return;
1502   }
1503 
1504   // A few slightly irregular cases:
1505   switch (klass_id) {
1506   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1507     // Second chance: check in regular Math.
1508     switch (name_id) {
1509     case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1510     case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1511     case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1512       // pretend it is the corresponding method in the non-strict class:
1513       klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1514       id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1515       break;
1516     default:
1517       break;
1518     }
1519     break;
1520 
1521   // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1522   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1523   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1524     if (!is_native())  break;
1525     id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1526     if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1527       id = vmIntrinsics::_none;
1528     break;
1529 
1530   default:
1531     break;
1532   }
1533 
1534   if (id != vmIntrinsics::_none) {
1535     // Set up its iid.  It is an alias method.
1536     set_intrinsic_id(id);
1537     return;
1538   }
1539 }
1540 
1541 // These two methods are static since a GC may move the Method
1542 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1543   if (!THREAD->can_call_java()) {
1544     // There is nothing useful this routine can do from within the Compile thread.
1545     // Hopefully, the signature contains only well-known classes.
1546     // We could scan for this and return true/false, but the caller won't care.
1547     return false;
1548   }
1549   bool sig_is_loaded = true;
1550   Handle class_loader(THREAD, m->method_holder()->class_loader());
1551   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1552   ResourceMark rm(THREAD);
1553   Symbol*  signature = m->signature();
1554   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1555     if (ss.is_object()) {
1556       Symbol* sym = ss.as_symbol(CHECK_(false));
1557       Symbol*  name  = sym;
1558       Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1559                                              protection_domain, THREAD);
1560       // We are loading classes eagerly. If a ClassNotFoundException or
1561       // a LinkageError was generated, be sure to ignore it.
1562       if (HAS_PENDING_EXCEPTION) {
1563         if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1564             PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1565           CLEAR_PENDING_EXCEPTION;
1566         } else {
1567           return false;
1568         }
1569       }
1570       if( klass == NULL) { sig_is_loaded = false; }
1571     }
1572   }
1573   return sig_is_loaded;
1574 }
1575 
1576 bool Method::has_unloaded_classes_in_signature(const methodHandle& m, TRAPS) {
1577   Handle class_loader(THREAD, m->method_holder()->class_loader());
1578   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1579   ResourceMark rm(THREAD);
1580   Symbol*  signature = m->signature();
1581   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1582     if (ss.type() == T_OBJECT) {
1583       Symbol* name = ss.as_symbol_or_null();
1584       if (name == NULL) return true;
1585       Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1586       if (klass == NULL) return true;
1587     }
1588   }
1589   return false;
1590 }
1591 
1592 // Exposed so field engineers can debug VM
1593 void Method::print_short_name(outputStream* st) {
1594   ResourceMark rm;
1595 #ifdef PRODUCT
1596   st->print(" %s::", method_holder()->external_name());
1597 #else
1598   st->print(" %s::", method_holder()->internal_name());
1599 #endif
1600   name()->print_symbol_on(st);
1601   if (WizardMode) signature()->print_symbol_on(st);
1602   else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1603     MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1604 }
1605 
1606 // Comparer for sorting an object array containing
1607 // Method*s.
1608 static int method_comparator(Method* a, Method* b) {
1609   return a->name()->fast_compare(b->name());
1610 }
1611 
1612 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1613 // default_methods also uses this without the ordering for fast find_method
1614 void Method::sort_methods(Array<Method*>* methods, bool idempotent, bool set_idnums) {
1615   int length = methods->length();
1616   if (length > 1) {
1617     {
1618       NoSafepointVerifier nsv;
1619       QuickSort::sort(methods->data(), length, method_comparator, idempotent);
1620     }
1621     // Reset method ordering
1622     if (set_idnums) {
1623       for (int i = 0; i < length; i++) {
1624         Method* m = methods->at(i);
1625         m->set_method_idnum(i);
1626         m->set_orig_method_idnum(i);
1627       }
1628     }
1629   }
1630 }
1631 
1632 //-----------------------------------------------------------------------------------
1633 // Non-product code unless JVM/TI needs it
1634 
1635 #if !defined(PRODUCT) || INCLUDE_JVMTI
1636 class SignatureTypePrinter : public SignatureTypeNames {
1637  private:
1638   outputStream* _st;
1639   bool _use_separator;
1640 
1641   void type_name(const char* name) {
1642     if (_use_separator) _st->print(", ");
1643     _st->print("%s", name);
1644     _use_separator = true;
1645   }
1646 
1647  public:
1648   SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1649     _st = st;
1650     _use_separator = false;
1651   }
1652 
1653   void print_parameters()              { _use_separator = false; iterate_parameters(); }
1654   void print_returntype()              { _use_separator = false; iterate_returntype(); }
1655 };
1656 
1657 
1658 void Method::print_name(outputStream* st) {
1659   Thread *thread = Thread::current();
1660   ResourceMark rm(thread);
1661   st->print("%s ", is_static() ? "static" : "virtual");
1662   if (WizardMode) {
1663     st->print("%s.", method_holder()->internal_name());
1664     name()->print_symbol_on(st);
1665     signature()->print_symbol_on(st);
1666   } else {
1667     SignatureTypePrinter sig(signature(), st);
1668     sig.print_returntype();
1669     st->print(" %s.", method_holder()->internal_name());
1670     name()->print_symbol_on(st);
1671     st->print("(");
1672     sig.print_parameters();
1673     st->print(")");
1674   }
1675 }
1676 #endif // !PRODUCT || INCLUDE_JVMTI
1677 
1678 
1679 void Method::print_codes_on(outputStream* st) const {
1680   print_codes_on(0, code_size(), st);
1681 }
1682 
1683 void Method::print_codes_on(int from, int to, outputStream* st) const {
1684   Thread *thread = Thread::current();
1685   ResourceMark rm(thread);
1686   methodHandle mh (thread, (Method*)this);
1687   BytecodeStream s(mh);
1688   s.set_interval(from, to);
1689   BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1690   while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1691 }
1692 
1693 
1694 // Simple compression of line number tables. We use a regular compressed stream, except that we compress deltas
1695 // between (bci,line) pairs since they are smaller. If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
1696 // we save it as one byte, otherwise we write a 0xFF escape character and use regular compression. 0x0 is used
1697 // as end-of-stream terminator.
1698 
1699 void CompressedLineNumberWriteStream::write_pair_regular(int bci_delta, int line_delta) {
1700   // bci and line number does not compress into single byte.
1701   // Write out escape character and use regular compression for bci and line number.
1702   write_byte((jubyte)0xFF);
1703   write_signed_int(bci_delta);
1704   write_signed_int(line_delta);
1705 }
1706 
1707 // See comment in method.hpp which explains why this exists.
1708 #if defined(_M_AMD64) && _MSC_VER >= 1400
1709 #pragma optimize("", off)
1710 void CompressedLineNumberWriteStream::write_pair(int bci, int line) {
1711   write_pair_inline(bci, line);
1712 }
1713 #pragma optimize("", on)
1714 #endif
1715 
1716 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1717   _bci = 0;
1718   _line = 0;
1719 };
1720 
1721 
1722 bool CompressedLineNumberReadStream::read_pair() {
1723   jubyte next = read_byte();
1724   // Check for terminator
1725   if (next == 0) return false;
1726   if (next == 0xFF) {
1727     // Escape character, regular compression used
1728     _bci  += read_signed_int();
1729     _line += read_signed_int();
1730   } else {
1731     // Single byte compression used
1732     _bci  += next >> 3;
1733     _line += next & 0x7;
1734   }
1735   return true;
1736 }
1737 
1738 #if INCLUDE_JVMTI
1739 
1740 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1741   BreakpointInfo* bp = method_holder()->breakpoints();
1742   for (; bp != NULL; bp = bp->next()) {
1743     if (bp->match(this, bci)) {
1744       return bp->orig_bytecode();
1745     }
1746   }
1747   {
1748     ResourceMark rm;
1749     fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1750   }
1751   return Bytecodes::_shouldnotreachhere;
1752 }
1753 
1754 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1755   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1756   BreakpointInfo* bp = method_holder()->breakpoints();
1757   for (; bp != NULL; bp = bp->next()) {
1758     if (bp->match(this, bci)) {
1759       bp->set_orig_bytecode(code);
1760       // and continue, in case there is more than one
1761     }
1762   }
1763 }
1764 
1765 void Method::set_breakpoint(int bci) {
1766   InstanceKlass* ik = method_holder();
1767   BreakpointInfo *bp = new BreakpointInfo(this, bci);
1768   bp->set_next(ik->breakpoints());
1769   ik->set_breakpoints(bp);
1770   // do this last:
1771   bp->set(this);
1772 }
1773 
1774 static void clear_matches(Method* m, int bci) {
1775   InstanceKlass* ik = m->method_holder();
1776   BreakpointInfo* prev_bp = NULL;
1777   BreakpointInfo* next_bp;
1778   for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1779     next_bp = bp->next();
1780     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1781     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1782       // do this first:
1783       bp->clear(m);
1784       // unhook it
1785       if (prev_bp != NULL)
1786         prev_bp->set_next(next_bp);
1787       else
1788         ik->set_breakpoints(next_bp);
1789       delete bp;
1790       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1791       // at same location. So we have multiple matching (method_index and bci)
1792       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1793       // breakpoint for clear_breakpoint request and keep all other method versions
1794       // BreakpointInfo for future clear_breakpoint request.
1795       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1796       // which is being called when class is unloaded. We delete all the Breakpoint
1797       // information for all versions of method. We may not correctly restore the original
1798       // bytecode in all method versions, but that is ok. Because the class is being unloaded
1799       // so these methods won't be used anymore.
1800       if (bci >= 0) {
1801         break;
1802       }
1803     } else {
1804       // This one is a keeper.
1805       prev_bp = bp;
1806     }
1807   }
1808 }
1809 
1810 void Method::clear_breakpoint(int bci) {
1811   assert(bci >= 0, "");
1812   clear_matches(this, bci);
1813 }
1814 
1815 void Method::clear_all_breakpoints() {
1816   clear_matches(this, -1);
1817 }
1818 
1819 #endif // INCLUDE_JVMTI
1820 
1821 int Method::invocation_count() {
1822   MethodCounters *mcs = method_counters();
1823   if (TieredCompilation) {
1824     MethodData* const mdo = method_data();
1825     if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1826         ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1827       return InvocationCounter::count_limit;
1828     } else {
1829       return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1830              ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1831     }
1832   } else {
1833     return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1834   }
1835 }
1836 
1837 int Method::backedge_count() {
1838   MethodCounters *mcs = method_counters();
1839   if (TieredCompilation) {
1840     MethodData* const mdo = method_data();
1841     if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1842         ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1843       return InvocationCounter::count_limit;
1844     } else {
1845       return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1846              ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1847     }
1848   } else {
1849     return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1850   }
1851 }
1852 
1853 int Method::highest_comp_level() const {
1854   const MethodCounters* mcs = method_counters();
1855   if (mcs != NULL) {
1856     return mcs->highest_comp_level();
1857   } else {
1858     return CompLevel_none;
1859   }
1860 }
1861 
1862 int Method::highest_osr_comp_level() const {
1863   const MethodCounters* mcs = method_counters();
1864   if (mcs != NULL) {
1865     return mcs->highest_osr_comp_level();
1866   } else {
1867     return CompLevel_none;
1868   }
1869 }
1870 
1871 void Method::set_highest_comp_level(int level) {
1872   MethodCounters* mcs = method_counters();
1873   if (mcs != NULL) {
1874     mcs->set_highest_comp_level(level);
1875   }
1876 }
1877 
1878 void Method::set_highest_osr_comp_level(int level) {
1879   MethodCounters* mcs = method_counters();
1880   if (mcs != NULL) {
1881     mcs->set_highest_osr_comp_level(level);
1882   }
1883 }
1884 
1885 #if INCLUDE_JVMTI
1886 
1887 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1888   _bci = bci;
1889   _name_index = m->name_index();
1890   _signature_index = m->signature_index();
1891   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1892   if (_orig_bytecode == Bytecodes::_breakpoint)
1893     _orig_bytecode = m->orig_bytecode_at(_bci);
1894   _next = NULL;
1895 }
1896 
1897 void BreakpointInfo::set(Method* method) {
1898 #ifdef ASSERT
1899   {
1900     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
1901     if (code == Bytecodes::_breakpoint)
1902       code = method->orig_bytecode_at(_bci);
1903     assert(orig_bytecode() == code, "original bytecode must be the same");
1904   }
1905 #endif
1906   Thread *thread = Thread::current();
1907   *method->bcp_from(_bci) = Bytecodes::_breakpoint;
1908   method->incr_number_of_breakpoints(thread);
1909   SystemDictionary::notice_modification();
1910   {
1911     // Deoptimize all dependents on this method
1912     HandleMark hm(thread);
1913     methodHandle mh(thread, method);
1914     CodeCache::flush_dependents_on_method(mh);
1915   }
1916 }
1917 
1918 void BreakpointInfo::clear(Method* method) {
1919   *method->bcp_from(_bci) = orig_bytecode();
1920   assert(method->number_of_breakpoints() > 0, "must not go negative");
1921   method->decr_number_of_breakpoints(Thread::current());
1922 }
1923 
1924 #endif // INCLUDE_JVMTI
1925 
1926 // jmethodID handling
1927 
1928 // This is a block allocating object, sort of like JNIHandleBlock, only a
1929 // lot simpler.
1930 // It's allocated on the CHeap because once we allocate a jmethodID, we can
1931 // never get rid of it.
1932 
1933 static const int min_block_size = 8;
1934 
1935 class JNIMethodBlockNode : public CHeapObj<mtClass> {
1936   friend class JNIMethodBlock;
1937   Method**        _methods;
1938   int             _number_of_methods;
1939   int             _top;
1940   JNIMethodBlockNode* _next;
1941 
1942  public:
1943 
1944   JNIMethodBlockNode(int num_methods = min_block_size);
1945 
1946   ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
1947 
1948   void ensure_methods(int num_addl_methods) {
1949     if (_top < _number_of_methods) {
1950       num_addl_methods -= _number_of_methods - _top;
1951       if (num_addl_methods <= 0) {
1952         return;
1953       }
1954     }
1955     if (_next == NULL) {
1956       _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
1957     } else {
1958       _next->ensure_methods(num_addl_methods);
1959     }
1960   }
1961 };
1962 
1963 class JNIMethodBlock : public CHeapObj<mtClass> {
1964   JNIMethodBlockNode _head;
1965   JNIMethodBlockNode *_last_free;
1966  public:
1967   static Method* const _free_method;
1968 
1969   JNIMethodBlock(int initial_capacity = min_block_size)
1970       : _head(initial_capacity), _last_free(&_head) {}
1971 
1972   void ensure_methods(int num_addl_methods) {
1973     _last_free->ensure_methods(num_addl_methods);
1974   }
1975 
1976   Method** add_method(Method* m) {
1977     for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
1978       if (b->_top < b->_number_of_methods) {
1979         // top points to the next free entry.
1980         int i = b->_top;
1981         b->_methods[i] = m;
1982         b->_top++;
1983         _last_free = b;
1984         return &(b->_methods[i]);
1985       } else if (b->_top == b->_number_of_methods) {
1986         // if the next free entry ran off the block see if there's a free entry
1987         for (int i = 0; i < b->_number_of_methods; i++) {
1988           if (b->_methods[i] == _free_method) {
1989             b->_methods[i] = m;
1990             _last_free = b;
1991             return &(b->_methods[i]);
1992           }
1993         }
1994         // Only check each block once for frees.  They're very unlikely.
1995         // Increment top past the end of the block.
1996         b->_top++;
1997       }
1998       // need to allocate a next block.
1999       if (b->_next == NULL) {
2000         b->_next = _last_free = new JNIMethodBlockNode();
2001       }
2002     }
2003     guarantee(false, "Should always allocate a free block");
2004     return NULL;
2005   }
2006 
2007   bool contains(Method** m) {
2008     if (m == NULL) return false;
2009     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2010       if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2011         // This is a bit of extra checking, for two reasons.  One is
2012         // that contains() deals with pointers that are passed in by
2013         // JNI code, so making sure that the pointer is aligned
2014         // correctly is valuable.  The other is that <= and > are
2015         // technically not defined on pointers, so the if guard can
2016         // pass spuriously; no modern compiler is likely to make that
2017         // a problem, though (and if one did, the guard could also
2018         // fail spuriously, which would be bad).
2019         ptrdiff_t idx = m - b->_methods;
2020         if (b->_methods + idx == m) {
2021           return true;
2022         }
2023       }
2024     }
2025     return false;  // not found
2026   }
2027 
2028   // Doesn't really destroy it, just marks it as free so it can be reused.
2029   void destroy_method(Method** m) {
2030 #ifdef ASSERT
2031     assert(contains(m), "should be a methodID");
2032 #endif // ASSERT
2033     *m = _free_method;
2034   }
2035 
2036   // During class unloading the methods are cleared, which is different
2037   // than freed.
2038   void clear_all_methods() {
2039     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2040       for (int i = 0; i< b->_number_of_methods; i++) {
2041         b->_methods[i] = NULL;
2042       }
2043     }
2044   }
2045 #ifndef PRODUCT
2046   int count_methods() {
2047     // count all allocated methods
2048     int count = 0;
2049     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2050       for (int i = 0; i< b->_number_of_methods; i++) {
2051         if (b->_methods[i] != _free_method) count++;
2052       }
2053     }
2054     return count;
2055   }
2056 #endif // PRODUCT
2057 };
2058 
2059 // Something that can't be mistaken for an address or a markOop
2060 Method* const JNIMethodBlock::_free_method = (Method*)55;
2061 
2062 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _next(NULL), _top(0) {
2063   _number_of_methods = MAX2(num_methods, min_block_size);
2064   _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2065   for (int i = 0; i < _number_of_methods; i++) {
2066     _methods[i] = JNIMethodBlock::_free_method;
2067   }
2068 }
2069 
2070 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
2071   ClassLoaderData* cld = loader_data;
2072   if (!SafepointSynchronize::is_at_safepoint()) {
2073     // Have to add jmethod_ids() to class loader data thread-safely.
2074     // Also have to add the method to the list safely, which the cld lock
2075     // protects as well.
2076     MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
2077     if (cld->jmethod_ids() == NULL) {
2078       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2079     } else {
2080       cld->jmethod_ids()->ensure_methods(capacity);
2081     }
2082   } else {
2083     // At safepoint, we are single threaded and can set this.
2084     if (cld->jmethod_ids() == NULL) {
2085       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2086     } else {
2087       cld->jmethod_ids()->ensure_methods(capacity);
2088     }
2089   }
2090 }
2091 
2092 // Add a method id to the jmethod_ids
2093 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
2094   ClassLoaderData* cld = loader_data;
2095 
2096   if (!SafepointSynchronize::is_at_safepoint()) {
2097     // Have to add jmethod_ids() to class loader data thread-safely.
2098     // Also have to add the method to the list safely, which the cld lock
2099     // protects as well.
2100     MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
2101     if (cld->jmethod_ids() == NULL) {
2102       cld->set_jmethod_ids(new JNIMethodBlock());
2103     }
2104     // jmethodID is a pointer to Method*
2105     return (jmethodID)cld->jmethod_ids()->add_method(m);
2106   } else {
2107     // At safepoint, we are single threaded and can set this.
2108     if (cld->jmethod_ids() == NULL) {
2109       cld->set_jmethod_ids(new JNIMethodBlock());
2110     }
2111     // jmethodID is a pointer to Method*
2112     return (jmethodID)cld->jmethod_ids()->add_method(m);
2113   }
2114 }
2115 
2116 // Mark a jmethodID as free.  This is called when there is a data race in
2117 // InstanceKlass while creating the jmethodID cache.
2118 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
2119   ClassLoaderData* cld = loader_data;
2120   Method** ptr = (Method**)m;
2121   assert(cld->jmethod_ids() != NULL, "should have method handles");
2122   cld->jmethod_ids()->destroy_method(ptr);
2123 }
2124 
2125 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2126   // Can't assert the method_holder is the same because the new method has the
2127   // scratch method holder.
2128   assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2129            == new_method->method_holder()->class_loader(),
2130          "changing to a different class loader");
2131   // Just change the method in place, jmethodID pointer doesn't change.
2132   *((Method**)jmid) = new_method;
2133 }
2134 
2135 bool Method::is_method_id(jmethodID mid) {
2136   Method* m = resolve_jmethod_id(mid);
2137   assert(m != NULL, "should be called with non-null method");
2138   InstanceKlass* ik = m->method_holder();
2139   ClassLoaderData* cld = ik->class_loader_data();
2140   if (cld->jmethod_ids() == NULL) return false;
2141   return (cld->jmethod_ids()->contains((Method**)mid));
2142 }
2143 
2144 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2145   if (mid == NULL) return NULL;
2146   Method* o = resolve_jmethod_id(mid);
2147   if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
2148     return NULL;
2149   }
2150   return o;
2151 };
2152 
2153 void Method::set_on_stack(const bool value) {
2154   // Set both the method itself and its constant pool.  The constant pool
2155   // on stack means some method referring to it is also on the stack.
2156   constants()->set_on_stack(value);
2157 
2158   bool already_set = on_stack();
2159   _access_flags.set_on_stack(value);
2160   if (value && !already_set) {
2161     MetadataOnStackMark::record(this);
2162   }
2163 }
2164 
2165 // Called when the class loader is unloaded to make all methods weak.
2166 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2167   loader_data->jmethod_ids()->clear_all_methods();
2168 }
2169 
2170 bool Method::has_method_vptr(const void* ptr) {
2171   Method m;
2172   // This assumes that the vtbl pointer is the first word of a C++ object.
2173   return dereference_vptr(&m) == dereference_vptr(ptr);
2174 }
2175 
2176 // Check that this pointer is valid by checking that the vtbl pointer matches
2177 bool Method::is_valid_method() const {
2178   if (this == NULL) {
2179     return false;
2180   } else if ((intptr_t(this) & (wordSize-1)) != 0) {
2181     // Quick sanity check on pointer.
2182     return false;
2183   } else if (is_shared()) {
2184     return MetaspaceShared::is_valid_shared_method(this);
2185   } else if (Metaspace::contains_non_shared(this)) {
2186     return has_method_vptr((const void*)this);
2187   } else {
2188     return false;
2189   }
2190 }
2191 
2192 #ifndef PRODUCT
2193 void Method::print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) {
2194   out->print_cr("jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2195 }
2196 #endif // PRODUCT
2197 
2198 
2199 // Printing
2200 
2201 #ifndef PRODUCT
2202 
2203 void Method::print_on(outputStream* st) const {
2204   ResourceMark rm;
2205   assert(is_method(), "must be method");
2206   st->print_cr("%s", internal_name());
2207   st->print_cr(" - this oop:          " INTPTR_FORMAT, p2i(this));
2208   st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();
2209   st->print   (" - constants:         " INTPTR_FORMAT " ", p2i(constants()));
2210   constants()->print_value_on(st); st->cr();
2211   st->print   (" - access:            0x%x  ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2212   st->print   (" - name:              ");    name()->print_value_on(st); st->cr();
2213   st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();
2214   st->print_cr(" - max stack:         %d",   max_stack());
2215   st->print_cr(" - max locals:        %d",   max_locals());
2216   st->print_cr(" - size of params:    %d",   size_of_parameters());
2217   st->print_cr(" - method size:       %d",   method_size());
2218   if (intrinsic_id() != vmIntrinsics::_none)
2219     st->print_cr(" - intrinsic id:      %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
2220   if (highest_comp_level() != CompLevel_none)
2221     st->print_cr(" - highest level:     %d", highest_comp_level());
2222   st->print_cr(" - vtable index:      %d",   _vtable_index);
2223   st->print_cr(" - i2i entry:         " INTPTR_FORMAT, p2i(interpreter_entry()));
2224   st->print(   " - adapters:          ");
2225   AdapterHandlerEntry* a = ((Method*)this)->adapter();
2226   if (a == NULL)
2227     st->print_cr(INTPTR_FORMAT, p2i(a));
2228   else
2229     a->print_adapter_on(st);
2230   st->print_cr(" - compiled entry     " INTPTR_FORMAT, p2i(from_compiled_entry()));
2231   st->print_cr(" - code size:         %d",   code_size());
2232   if (code_size() != 0) {
2233     st->print_cr(" - code start:        " INTPTR_FORMAT, p2i(code_base()));
2234     st->print_cr(" - code end (excl):   " INTPTR_FORMAT, p2i(code_base() + code_size()));
2235   }
2236   if (method_data() != NULL) {
2237     st->print_cr(" - method data:       " INTPTR_FORMAT, p2i(method_data()));
2238   }
2239   st->print_cr(" - checked ex length: %d",   checked_exceptions_length());
2240   if (checked_exceptions_length() > 0) {
2241     CheckedExceptionElement* table = checked_exceptions_start();
2242     st->print_cr(" - checked ex start:  " INTPTR_FORMAT, p2i(table));
2243     if (Verbose) {
2244       for (int i = 0; i < checked_exceptions_length(); i++) {
2245         st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2246       }
2247     }
2248   }
2249   if (has_linenumber_table()) {
2250     u_char* table = compressed_linenumber_table();
2251     st->print_cr(" - linenumber start:  " INTPTR_FORMAT, p2i(table));
2252     if (Verbose) {
2253       CompressedLineNumberReadStream stream(table);
2254       while (stream.read_pair()) {
2255         st->print_cr("   - line %d: %d", stream.line(), stream.bci());
2256       }
2257     }
2258   }
2259   st->print_cr(" - localvar length:   %d",   localvariable_table_length());
2260   if (localvariable_table_length() > 0) {
2261     LocalVariableTableElement* table = localvariable_table_start();
2262     st->print_cr(" - localvar start:    " INTPTR_FORMAT, p2i(table));
2263     if (Verbose) {
2264       for (int i = 0; i < localvariable_table_length(); i++) {
2265         int bci = table[i].start_bci;
2266         int len = table[i].length;
2267         const char* name = constants()->printable_name_at(table[i].name_cp_index);
2268         const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2269         int slot = table[i].slot;
2270         st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2271       }
2272     }
2273   }
2274   if (code() != NULL) {
2275     st->print   (" - compiled code: ");
2276     code()->print_value_on(st);
2277   }
2278   if (is_native()) {
2279     st->print_cr(" - native function:   " INTPTR_FORMAT, p2i(native_function()));
2280     st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2281   }
2282 }
2283 
2284 void Method::print_linkage_flags(outputStream* st) {
2285   access_flags().print_on(st);
2286   if (is_default_method()) {
2287     st->print("default ");
2288   }
2289   if (is_overpass()) {
2290     st->print("overpass ");
2291   }
2292 }
2293 #endif //PRODUCT
2294 
2295 void Method::print_value_on(outputStream* st) const {
2296   assert(is_method(), "must be method");
2297   st->print("%s", internal_name());
2298   print_address_on(st);
2299   st->print(" ");
2300   name()->print_value_on(st);
2301   st->print(" ");
2302   signature()->print_value_on(st);
2303   st->print(" in ");
2304   method_holder()->print_value_on(st);
2305   if (WizardMode) st->print("#%d", _vtable_index);
2306   if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2307   if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2308 }
2309 
2310 #if INCLUDE_SERVICES
2311 // Size Statistics
2312 void Method::collect_statistics(KlassSizeStats *sz) const {
2313   int mysize = sz->count(this);
2314   sz->_method_bytes += mysize;
2315   sz->_method_all_bytes += mysize;
2316   sz->_rw_bytes += mysize;
2317 
2318   if (constMethod()) {
2319     constMethod()->collect_statistics(sz);
2320   }
2321   if (method_data()) {
2322     method_data()->collect_statistics(sz);
2323   }
2324 }
2325 #endif // INCLUDE_SERVICES
2326 
2327 // LogTouchedMethods and PrintTouchedMethods
2328 
2329 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2330 // the Method may be garbage collected. Let's roll our own hash table.
2331 class TouchedMethodRecord : CHeapObj<mtTracing> {
2332 public:
2333   // It's OK to store Symbols here because they will NOT be GC'ed if
2334   // LogTouchedMethods is enabled.
2335   TouchedMethodRecord* _next;
2336   Symbol* _class_name;
2337   Symbol* _method_name;
2338   Symbol* _method_signature;
2339 };
2340 
2341 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2342 static TouchedMethodRecord** _touched_method_table = NULL;
2343 
2344 void Method::log_touched(TRAPS) {
2345 
2346   const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2347   Symbol* my_class = klass_name();
2348   Symbol* my_name  = name();
2349   Symbol* my_sig   = signature();
2350 
2351   unsigned int hash = my_class->identity_hash() +
2352                       my_name->identity_hash() +
2353                       my_sig->identity_hash();
2354   juint index = juint(hash) % table_size;
2355 
2356   MutexLocker ml(TouchedMethodLog_lock, THREAD);
2357   if (_touched_method_table == NULL) {
2358     _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2359                                               mtTracing, CURRENT_PC);
2360     memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2361   }
2362 
2363   TouchedMethodRecord* ptr = _touched_method_table[index];
2364   while (ptr) {
2365     if (ptr->_class_name       == my_class &&
2366         ptr->_method_name      == my_name &&
2367         ptr->_method_signature == my_sig) {
2368       return;
2369     }
2370     if (ptr->_next == NULL) break;
2371     ptr = ptr->_next;
2372   }
2373   TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2374   my_class->set_permanent();  // prevent reclaimed by GC
2375   my_name->set_permanent();
2376   my_sig->set_permanent();
2377   nptr->_class_name         = my_class;
2378   nptr->_method_name        = my_name;
2379   nptr->_method_signature   = my_sig;
2380   nptr->_next               = NULL;
2381 
2382   if (ptr == NULL) {
2383     // first
2384     _touched_method_table[index] = nptr;
2385   } else {
2386     ptr->_next = nptr;
2387   }
2388 }
2389 
2390 void Method::print_touched_methods(outputStream* out) {
2391   MutexLockerEx ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2392   out->print_cr("# Method::print_touched_methods version 1");
2393   if (_touched_method_table) {
2394     for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2395       TouchedMethodRecord* ptr = _touched_method_table[i];
2396       while(ptr) {
2397         ptr->_class_name->print_symbol_on(out);       out->print(".");
2398         ptr->_method_name->print_symbol_on(out);      out->print(":");
2399         ptr->_method_signature->print_symbol_on(out); out->cr();
2400         ptr = ptr->_next;
2401       }
2402     }
2403   }
2404 }
2405 
2406 // Verification
2407 
2408 void Method::verify_on(outputStream* st) {
2409   guarantee(is_method(), "object must be method");
2410   guarantee(constants()->is_constantPool(), "should be constant pool");
2411   guarantee(constMethod()->is_constMethod(), "should be ConstMethod*");
2412   MethodData* md = method_data();
2413   guarantee(md == NULL ||
2414       md->is_methodData(), "should be method data");
2415 }