1 /*
   2  * Copyright (c) 1997, 2019, 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/classLoaderDataGraph.hpp"
  27 #include "classfile/metadataOnStackMark.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "code/codeCache.hpp"
  30 #include "code/debugInfoRec.hpp"
  31 #include "gc/shared/collectedHeap.inline.hpp"
  32 #include "interpreter/bytecodeStream.hpp"
  33 #include "interpreter/bytecodeTracer.hpp"
  34 #include "interpreter/bytecodes.hpp"
  35 #include "interpreter/interpreter.hpp"
  36 #include "interpreter/oopMapCache.hpp"
  37 #include "memory/allocation.inline.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/constantPool.hpp"
  46 #include "oops/method.inline.hpp"
  47 #include "oops/methodData.hpp"
  48 #include "oops/objArrayOop.inline.hpp"
  49 #include "oops/oop.inline.hpp"
  50 #include "oops/symbol.hpp"
  51 #include "oops/valueKlass.hpp"
  52 #include "prims/jvmtiExport.hpp"
  53 #include "prims/methodHandles.hpp"
  54 #include "prims/nativeLookup.hpp"
  55 #include "runtime/arguments.hpp"
  56 #include "runtime/compilationPolicy.hpp"
  57 #include "runtime/frame.inline.hpp"
  58 #include "runtime/handles.inline.hpp"
  59 #include "runtime/init.hpp"
  60 #include "runtime/orderAccess.hpp"
  61 #include "runtime/relocator.hpp"
  62 #include "runtime/safepointVerifiers.hpp"
  63 #include "runtime/sharedRuntime.hpp"
  64 #include "runtime/signature.hpp"
  65 #include "utilities/align.hpp"
  66 #include "utilities/quickSort.hpp"
  67 #include "utilities/vmError.hpp"
  68 #include "utilities/xmlstream.hpp"
  69 
  70 // Implementation of Method
  71 
  72 Method* Method::allocate(ClassLoaderData* loader_data,
  73                          int byte_code_size,
  74                          AccessFlags access_flags,
  75                          InlineTableSizes* sizes,
  76                          ConstMethod::MethodType method_type,
  77                          TRAPS) {
  78   assert(!access_flags.is_native() || byte_code_size == 0,
  79          "native methods should not contain byte codes");
  80   ConstMethod* cm = ConstMethod::allocate(loader_data,
  81                                           byte_code_size,
  82                                           sizes,
  83                                           method_type,
  84                                           CHECK_NULL);
  85   int size = Method::size(access_flags.is_native());
  86   return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
  87 }
  88 
  89 Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
  90   NoSafepointVerifier no_safepoint;
  91   set_constMethod(xconst);
  92   set_access_flags(access_flags);
  93   set_intrinsic_id(vmIntrinsics::_none);
  94   set_force_inline(false);
  95   set_hidden(false);
  96   set_dont_inline(false);
  97   set_has_injected_profile(false);
  98   set_method_data(NULL);
  99   clear_method_counters();
 100   set_vtable_index(Method::garbage_vtable_index);
 101 
 102   // Fix and bury in Method*
 103   set_interpreter_entry(NULL); // sets i2i entry and from_int
 104   set_adapter_entry(NULL);
 105   clear_code(false /* don't need a lock */); // from_c/from_i get set to c2i/i2i
 106 
 107   if (access_flags.is_native()) {
 108     clear_native_function();
 109     set_signature_handler(NULL);
 110   }
 111   NOT_PRODUCT(set_compiled_invocation_count(0);)
 112 }
 113 
 114 // Release Method*.  The nmethod will be gone when we get here because
 115 // we've walked the code cache.
 116 void Method::deallocate_contents(ClassLoaderData* loader_data) {
 117   MetadataFactory::free_metadata(loader_data, constMethod());
 118   set_constMethod(NULL);
 119   MetadataFactory::free_metadata(loader_data, method_data());
 120   set_method_data(NULL);
 121   MetadataFactory::free_metadata(loader_data, method_counters());
 122   clear_method_counters();
 123   // The nmethod will be gone when we get here.
 124   if (code() != NULL) _code = NULL;
 125 }
 126 
 127 address Method::get_i2c_entry() {
 128   assert(adapter() != NULL, "must have");
 129   return adapter()->get_i2c_entry();
 130 }
 131 
 132 address Method::get_c2i_entry() {
 133   assert(adapter() != NULL, "must have");
 134   return adapter()->get_c2i_entry();
 135 }
 136 
 137 address Method::get_c2i_unverified_entry() {
 138   assert(adapter() != NULL, "must have");
 139   return adapter()->get_c2i_unverified_entry();
 140 }
 141 
 142 char* Method::name_and_sig_as_C_string() const {
 143   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
 144 }
 145 
 146 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
 147   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
 148 }
 149 
 150 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
 151   const char* klass_name = klass->external_name();
 152   int klass_name_len  = (int)strlen(klass_name);
 153   int method_name_len = method_name->utf8_length();
 154   int len             = klass_name_len + 1 + method_name_len + signature->utf8_length();
 155   char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);
 156   strcpy(dest, klass_name);
 157   dest[klass_name_len] = '.';
 158   strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
 159   strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
 160   dest[len] = 0;
 161   return dest;
 162 }
 163 
 164 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
 165   Symbol* klass_name = klass->name();
 166   klass_name->as_klass_external_name(buf, size);
 167   int len = (int)strlen(buf);
 168 
 169   if (len < size - 1) {
 170     buf[len++] = '.';
 171 
 172     method_name->as_C_string(&(buf[len]), size - len);
 173     len = (int)strlen(buf);
 174 
 175     signature->as_C_string(&(buf[len]), size - len);
 176   }
 177 
 178   return buf;
 179 }
 180 
 181 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
 182   // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
 183   // access exception table
 184   ExceptionTable table(mh());
 185   int length = table.length();
 186   // iterate through all entries sequentially
 187   constantPoolHandle pool(THREAD, mh->constants());
 188   for (int i = 0; i < length; i ++) {
 189     //reacquire the table in case a GC happened
 190     ExceptionTable table(mh());
 191     int beg_bci = table.start_pc(i);
 192     int end_bci = table.end_pc(i);
 193     assert(beg_bci <= end_bci, "inconsistent exception table");
 194     if (beg_bci <= throw_bci && throw_bci < end_bci) {
 195       // exception handler bci range covers throw_bci => investigate further
 196       int handler_bci = table.handler_pc(i);
 197       int klass_index = table.catch_type_index(i);
 198       if (klass_index == 0) {
 199         return handler_bci;
 200       } else if (ex_klass == NULL) {
 201         return handler_bci;
 202       } else {
 203         // we know the exception class => get the constraint class
 204         // this may require loading of the constraint class; if verification
 205         // fails or some other exception occurs, return handler_bci
 206         Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
 207         assert(k != NULL, "klass not loaded");
 208         if (ex_klass->is_subtype_of(k)) {
 209           return handler_bci;
 210         }
 211       }
 212     }
 213   }
 214 
 215   return -1;
 216 }
 217 
 218 void Method::mask_for(int bci, InterpreterOopMap* mask) {
 219   methodHandle h_this(Thread::current(), this);
 220   // Only GC uses the OopMapCache during thread stack root scanning
 221   // any other uses generate an oopmap but do not save it in the cache.
 222   if (Universe::heap()->is_gc_active()) {
 223     method_holder()->mask_for(h_this, bci, mask);
 224   } else {
 225     OopMapCache::compute_one_oop_map(h_this, bci, mask);
 226   }
 227   return;
 228 }
 229 
 230 
 231 int Method::bci_from(address bcp) const {
 232   if (is_native() && bcp == 0) {
 233     return 0;
 234   }
 235 #ifdef ASSERT
 236   {
 237     ResourceMark rm;
 238     assert(is_native() && bcp == code_base() || contains(bcp) || VMError::is_error_reported(),
 239            "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
 240            p2i(bcp), name_and_sig_as_C_string());
 241   }
 242 #endif
 243   return bcp - code_base();
 244 }
 245 
 246 
 247 int Method::validate_bci(int bci) const {
 248   return (bci == 0 || bci < code_size()) ? bci : -1;
 249 }
 250 
 251 // Return bci if it appears to be a valid bcp
 252 // Return -1 otherwise.
 253 // Used by profiling code, when invalid data is a possibility.
 254 // The caller is responsible for validating the Method* itself.
 255 int Method::validate_bci_from_bcp(address bcp) const {
 256   // keep bci as -1 if not a valid bci
 257   int bci = -1;
 258   if (bcp == 0 || bcp == code_base()) {
 259     // code_size() may return 0 and we allow 0 here
 260     // the method may be native
 261     bci = 0;
 262   } else if (contains(bcp)) {
 263     bci = bcp - code_base();
 264   }
 265   // Assert that if we have dodged any asserts, bci is negative.
 266   assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
 267   return bci;
 268 }
 269 
 270 address Method::bcp_from(int bci) const {
 271   assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
 272          "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
 273   address bcp = code_base() + bci;
 274   assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
 275   return bcp;
 276 }
 277 
 278 address Method::bcp_from(address bcp) const {
 279   if (is_native() && bcp == NULL) {
 280     return code_base();
 281   } else {
 282     return bcp;
 283   }
 284 }
 285 
 286 int Method::size(bool is_native) {
 287   // If native, then include pointers for native_function and signature_handler
 288   int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
 289   int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
 290   return align_metadata_size(header_size() + extra_words);
 291 }
 292 
 293 
 294 Symbol* Method::klass_name() const {
 295   return method_holder()->name();
 296 }
 297 
 298 
 299 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
 300   log_trace(cds)("Iter(Method): %p", this);
 301 
 302   it->push(&_constMethod);
 303   it->push(&_method_data);
 304   it->push(&_method_counters);
 305 }
 306 
 307 // Attempt to return method oop to original state.  Clear any pointers
 308 // (to objects outside the shared spaces).  We won't be able to predict
 309 // where they should point in a new JVM.  Further initialize some
 310 // entries now in order allow them to be write protected later.
 311 
 312 void Method::remove_unshareable_info() {
 313   unlink_method();
 314 }
 315 
 316 void Method::set_vtable_index(int index) {
 317   if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
 318     // At runtime initialize_vtable is rerun as part of link_class_impl()
 319     // for a shared class loaded by the non-boot loader to obtain the loader
 320     // constraints based on the runtime classloaders' context.
 321     return; // don't write into the shared class
 322   } else {
 323     _vtable_index = index;
 324   }
 325 }
 326 
 327 void Method::set_itable_index(int index) {
 328   if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
 329     // At runtime initialize_itable is rerun as part of link_class_impl()
 330     // for a shared class loaded by the non-boot loader to obtain the loader
 331     // constraints based on the runtime classloaders' context. The dumptime
 332     // itable index should be the same as the runtime index.
 333     assert(_vtable_index == itable_index_max - index,
 334            "archived itable index is different from runtime index");
 335     return; // don’t write into the shared class
 336   } else {
 337     _vtable_index = itable_index_max - index;
 338   }
 339   assert(valid_itable_index(), "");
 340 }
 341 
 342 
 343 
 344 bool Method::was_executed_more_than(int n) {
 345   // Invocation counter is reset when the Method* is compiled.
 346   // If the method has compiled code we therefore assume it has
 347   // be excuted more than n times.
 348   if (is_accessor() || is_empty_method() || (code() != NULL)) {
 349     // interpreter doesn't bump invocation counter of trivial methods
 350     // compiler does not bump invocation counter of compiled methods
 351     return true;
 352   }
 353   else if ((method_counters() != NULL &&
 354             method_counters()->invocation_counter()->carry()) ||
 355            (method_data() != NULL &&
 356             method_data()->invocation_counter()->carry())) {
 357     // The carry bit is set when the counter overflows and causes
 358     // a compilation to occur.  We don't know how many times
 359     // the counter has been reset, so we simply assume it has
 360     // been executed more than n times.
 361     return true;
 362   } else {
 363     return invocation_count() > n;
 364   }
 365 }
 366 
 367 void Method::print_invocation_count() {
 368   if (is_static()) tty->print("static ");
 369   if (is_final()) tty->print("final ");
 370   if (is_synchronized()) tty->print("synchronized ");
 371   if (is_native()) tty->print("native ");
 372   tty->print("%s::", method_holder()->external_name());
 373   name()->print_symbol_on(tty);
 374   signature()->print_symbol_on(tty);
 375 
 376   if (WizardMode) {
 377     // dump the size of the byte codes
 378     tty->print(" {%d}", code_size());
 379   }
 380   tty->cr();
 381 
 382   tty->print_cr ("  interpreter_invocation_count: %8d ", interpreter_invocation_count());
 383   tty->print_cr ("  invocation_counter:           %8d ", invocation_count());
 384   tty->print_cr ("  backedge_counter:             %8d ", backedge_count());
 385 #ifndef PRODUCT
 386   if (CountCompiledCalls) {
 387     tty->print_cr ("  compiled_invocation_count: %8d ", compiled_invocation_count());
 388   }
 389 #endif
 390 }
 391 
 392 // Build a MethodData* object to hold information about this method
 393 // collected in the interpreter.
 394 void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) {
 395   // Do not profile the method if metaspace has hit an OOM previously
 396   // allocating profiling data. Callers clear pending exception so don't
 397   // add one here.
 398   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 399     return;
 400   }
 401 
 402   // Grab a lock here to prevent multiple
 403   // MethodData*s from being created.
 404   MutexLocker ml(MethodData_lock, THREAD);
 405   if (method->method_data() == NULL) {
 406     ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
 407     MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
 408     if (HAS_PENDING_EXCEPTION) {
 409       CompileBroker::log_metaspace_failure();
 410       ClassLoaderDataGraph::set_metaspace_oom(true);
 411       return;   // return the exception (which is cleared)
 412     }
 413 
 414     method->set_method_data(method_data);
 415     if (PrintMethodData && (Verbose || WizardMode)) {
 416       ResourceMark rm(THREAD);
 417       tty->print("build_interpreter_method_data for ");
 418       method->print_name(tty);
 419       tty->cr();
 420       // At the end of the run, the MDO, full of data, will be dumped.
 421     }
 422   }
 423 }
 424 
 425 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
 426   // Do not profile the method if metaspace has hit an OOM previously
 427   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 428     return NULL;
 429   }
 430 
 431   methodHandle mh(m);
 432   MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
 433   if (HAS_PENDING_EXCEPTION) {
 434     CompileBroker::log_metaspace_failure();
 435     ClassLoaderDataGraph::set_metaspace_oom(true);
 436     return NULL;   // return the exception (which is cleared)
 437   }
 438   if (!mh->init_method_counters(counters)) {
 439     MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
 440   }
 441 
 442   if (LogTouchedMethods) {
 443     mh->log_touched(CHECK_NULL);
 444   }
 445 
 446   return mh->method_counters();
 447 }
 448 
 449 bool Method::init_method_counters(MethodCounters* counters) {
 450   // Try to install a pointer to MethodCounters, return true on success.
 451   return Atomic::replace_if_null(counters, &_method_counters);
 452 }
 453 
 454 int Method::extra_stack_words() {
 455   // not an inline function, to avoid a header dependency on Interpreter
 456   return extra_stack_entries() * Interpreter::stackElementSize;
 457 }
 458 
 459 
 460 void Method::compute_size_of_parameters(Thread *thread) {
 461   ArgumentSizeComputer asc(signature());
 462   set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
 463 }
 464 
 465 BasicType Method::result_type() const {
 466   ResultTypeFinder rtf(signature());
 467   return rtf.type();
 468 }
 469 
 470 #ifdef ASSERT
 471 // ValueKlass the method is declared to return. This must not
 472 // safepoint as it is called with references live on the stack at
 473 // locations the GC is unaware of.
 474 ValueKlass* Method::returned_value_type(Thread* thread) const {
 475   SignatureStream ss(signature());
 476   while (!ss.at_return_type()) {
 477     ss.next();
 478   }
 479   Handle class_loader(thread, method_holder()->class_loader());
 480   Handle protection_domain(thread, method_holder()->protection_domain());
 481   Klass* k = NULL;
 482   {
 483     NoSafepointVerifier nsv;
 484     k = ss.as_klass(class_loader, protection_domain, SignatureStream::ReturnNull, thread);
 485   }
 486   assert(k != NULL && !thread->has_pending_exception(), "can't resolve klass");
 487   return ValueKlass::cast(k);
 488 }
 489 #endif
 490 
 491 bool Method::is_empty_method() const {
 492   return  code_size() == 1
 493       && *code_base() == Bytecodes::_return;
 494 }
 495 
 496 
 497 bool Method::is_vanilla_constructor() const {
 498   // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
 499   // which only calls the superclass vanilla constructor and possibly does stores of
 500   // zero constants to local fields:
 501   //
 502   //   aload_0
 503   //   invokespecial
 504   //   indexbyte1
 505   //   indexbyte2
 506   //
 507   // followed by an (optional) sequence of:
 508   //
 509   //   aload_0
 510   //   aconst_null / iconst_0 / fconst_0 / dconst_0
 511   //   putfield
 512   //   indexbyte1
 513   //   indexbyte2
 514   //
 515   // followed by:
 516   //
 517   //   return
 518 
 519   assert(name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructors");
 520   assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
 521   int size = code_size();
 522   // Check if size match
 523   if (size == 0 || size % 5 != 0) return false;
 524   address cb = code_base();
 525   int last = size - 1;
 526   if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
 527     // Does not call superclass default constructor
 528     return false;
 529   }
 530   // Check optional sequence
 531   for (int i = 4; i < last; i += 5) {
 532     if (cb[i] != Bytecodes::_aload_0) return false;
 533     if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
 534     if (cb[i+2] != Bytecodes::_putfield) return false;
 535   }
 536   return true;
 537 }
 538 
 539 
 540 bool Method::compute_has_loops_flag() {
 541   BytecodeStream bcs(this);
 542   Bytecodes::Code bc;
 543 
 544   while ((bc = bcs.next()) >= 0) {
 545     switch( bc ) {
 546       case Bytecodes::_ifeq:
 547       case Bytecodes::_ifnull:
 548       case Bytecodes::_iflt:
 549       case Bytecodes::_ifle:
 550       case Bytecodes::_ifne:
 551       case Bytecodes::_ifnonnull:
 552       case Bytecodes::_ifgt:
 553       case Bytecodes::_ifge:
 554       case Bytecodes::_if_icmpeq:
 555       case Bytecodes::_if_icmpne:
 556       case Bytecodes::_if_icmplt:
 557       case Bytecodes::_if_icmpgt:
 558       case Bytecodes::_if_icmple:
 559       case Bytecodes::_if_icmpge:
 560       case Bytecodes::_if_acmpeq:
 561       case Bytecodes::_if_acmpne:
 562       case Bytecodes::_goto:
 563       case Bytecodes::_jsr:
 564         if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
 565         break;
 566 
 567       case Bytecodes::_goto_w:
 568       case Bytecodes::_jsr_w:
 569         if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
 570         break;
 571 
 572       default:
 573         break;
 574     }
 575   }
 576   _access_flags.set_loops_flag_init();
 577   return _access_flags.has_loops();
 578 }
 579 
 580 bool Method::is_final_method(AccessFlags class_access_flags) const {
 581   // or "does_not_require_vtable_entry"
 582   // default method or overpass can occur, is not final (reuses vtable entry)
 583   // private methods in classes get vtable entries for backward class compatibility.
 584   if (is_overpass() || is_default_method())  return false;
 585   return is_final() || class_access_flags.is_final();
 586 }
 587 
 588 bool Method::is_final_method() const {
 589   return is_final_method(method_holder()->access_flags());
 590 }
 591 
 592 bool Method::is_default_method() const {
 593   if (method_holder() != NULL &&
 594       method_holder()->is_interface() &&
 595       !is_abstract() && !is_private()) {
 596     return true;
 597   } else {
 598     return false;
 599   }
 600 }
 601 
 602 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
 603   if (is_final_method(class_access_flags))  return true;
 604 #ifdef ASSERT
 605   ResourceMark rm;
 606   bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
 607   if (class_access_flags.is_interface()) {
 608       assert(is_nonv == is_static() || is_nonv == is_private(),
 609              "nonvirtual unexpected for non-static, non-private: %s",
 610              name_and_sig_as_C_string());
 611   }
 612 #endif
 613   assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
 614   return vtable_index() == nonvirtual_vtable_index;
 615 }
 616 
 617 bool Method::can_be_statically_bound() const {
 618   return can_be_statically_bound(method_holder()->access_flags());
 619 }
 620 
 621 bool Method::is_accessor() const {
 622   return is_getter() || is_setter();
 623 }
 624 
 625 bool Method::is_getter() const {
 626   if (code_size() != 5) return false;
 627   if (size_of_parameters() != 1) return false;
 628   if (java_code_at(0) != Bytecodes::_aload_0)  return false;
 629   if (java_code_at(1) != Bytecodes::_getfield) return false;
 630   switch (java_code_at(4)) {
 631     case Bytecodes::_ireturn:
 632     case Bytecodes::_lreturn:
 633     case Bytecodes::_freturn:
 634     case Bytecodes::_dreturn:
 635     case Bytecodes::_areturn:
 636       break;
 637     default:
 638       return false;
 639   }
 640   return true;
 641 }
 642 
 643 bool Method::is_setter() const {
 644   if (code_size() != 6) return false;
 645   if (java_code_at(0) != Bytecodes::_aload_0) return false;
 646   switch (java_code_at(1)) {
 647     case Bytecodes::_iload_1:
 648     case Bytecodes::_aload_1:
 649     case Bytecodes::_fload_1:
 650       if (size_of_parameters() != 2) return false;
 651       break;
 652     case Bytecodes::_dload_1:
 653     case Bytecodes::_lload_1:
 654       if (size_of_parameters() != 3) return false;
 655       break;
 656     default:
 657       return false;
 658   }
 659   if (java_code_at(2) != Bytecodes::_putfield) return false;
 660   if (java_code_at(5) != Bytecodes::_return)   return false;
 661   return true;
 662 }
 663 
 664 bool Method::is_constant_getter() const {
 665   int last_index = code_size() - 1;
 666   // Check if the first 1-3 bytecodes are a constant push
 667   // and the last bytecode is a return.
 668   return (2 <= code_size() && code_size() <= 4 &&
 669           Bytecodes::is_const(java_code_at(0)) &&
 670           Bytecodes::length_for(java_code_at(0)) == last_index &&
 671           Bytecodes::is_return(java_code_at(last_index)));
 672 }
 673 
 674 bool Method::is_initializer() const {
 675   return is_object_initializer() || is_static_initializer();
 676 }
 677 
 678 bool Method::has_valid_initializer_flags() const {
 679   return (is_static() ||
 680           method_holder()->major_version() < 51);
 681 }
 682 
 683 bool Method::is_static_initializer() const {
 684   // For classfiles version 51 or greater, ensure that the clinit method is
 685   // static.  Non-static methods with the name "<clinit>" are not static
 686   // initializers. (older classfiles exempted for backward compatibility)
 687   return name() == vmSymbols::class_initializer_name() &&
 688          has_valid_initializer_flags();
 689 }
 690 
 691 bool Method::is_object_initializer() const {
 692    return name() == vmSymbols::object_initializer_name();
 693 }
 694 
 695 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
 696   int length = method->checked_exceptions_length();
 697   if (length == 0) {  // common case
 698     return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
 699   } else {
 700     methodHandle h_this(THREAD, method);
 701     objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
 702     objArrayHandle mirrors (THREAD, m_oop);
 703     for (int i = 0; i < length; i++) {
 704       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
 705       Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
 706       assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
 707       mirrors->obj_at_put(i, k->java_mirror());
 708     }
 709     return mirrors;
 710   }
 711 };
 712 
 713 
 714 int Method::line_number_from_bci(int bci) const {
 715   int best_bci  =  0;
 716   int best_line = -1;
 717   if (bci == SynchronizationEntryBCI) bci = 0;
 718   if (0 <= bci && bci < code_size() && has_linenumber_table()) {
 719     // The line numbers are a short array of 2-tuples [start_pc, line_number].
 720     // Not necessarily sorted and not necessarily one-to-one.
 721     CompressedLineNumberReadStream stream(compressed_linenumber_table());
 722     while (stream.read_pair()) {
 723       if (stream.bci() == bci) {
 724         // perfect match
 725         return stream.line();
 726       } else {
 727         // update best_bci/line
 728         if (stream.bci() < bci && stream.bci() >= best_bci) {
 729           best_bci  = stream.bci();
 730           best_line = stream.line();
 731         }
 732       }
 733     }
 734   }
 735   return best_line;
 736 }
 737 
 738 
 739 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
 740   if( constants()->tag_at(klass_index).is_unresolved_klass()) {
 741     Thread *thread = Thread::current();
 742     Symbol* klass_name = constants()->klass_name_at(klass_index);
 743     Handle loader(thread, method_holder()->class_loader());
 744     Handle prot  (thread, method_holder()->protection_domain());
 745     return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
 746   } else {
 747     return true;
 748   }
 749 }
 750 
 751 
 752 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
 753   int klass_index = constants()->klass_ref_index_at(refinfo_index);
 754   if (must_be_resolved) {
 755     // Make sure klass is resolved in constantpool.
 756     if (constants()->tag_at(klass_index).is_unresolved_klass()) {
 757       return false;
 758     }
 759   }
 760   return is_klass_loaded_by_klass_index(klass_index);
 761 }
 762 
 763 
 764 void Method::set_native_function(address function, bool post_event_flag) {
 765   assert(function != NULL, "use clear_native_function to unregister natives");
 766   assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
 767   address* native_function = native_function_addr();
 768 
 769   // We can see racers trying to place the same native function into place. Once
 770   // is plenty.
 771   address current = *native_function;
 772   if (current == function) return;
 773   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
 774       function != NULL) {
 775     // native_method_throw_unsatisfied_link_error_entry() should only
 776     // be passed when post_event_flag is false.
 777     assert(function !=
 778       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 779       "post_event_flag mis-match");
 780 
 781     // post the bind event, and possible change the bind function
 782     JvmtiExport::post_native_method_bind(this, &function);
 783   }
 784   *native_function = function;
 785   // This function can be called more than once. We must make sure that we always
 786   // use the latest registered method -> check if a stub already has been generated.
 787   // If so, we have to make it not_entrant.
 788   CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates
 789   if (nm != NULL) {
 790     nm->make_not_entrant();
 791   }
 792 }
 793 
 794 
 795 bool Method::has_native_function() const {
 796   if (is_method_handle_intrinsic())
 797     return false;  // special-cased in SharedRuntime::generate_native_wrapper
 798   address func = native_function();
 799   return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
 800 }
 801 
 802 
 803 void Method::clear_native_function() {
 804   // Note: is_method_handle_intrinsic() is allowed here.
 805   set_native_function(
 806     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 807     !native_bind_event_is_interesting);
 808   clear_code();
 809 }
 810 
 811 address Method::critical_native_function() {
 812   methodHandle mh(this);
 813   return NativeLookup::lookup_critical_entry(mh);
 814 }
 815 
 816 
 817 void Method::set_signature_handler(address handler) {
 818   address* signature_handler =  signature_handler_addr();
 819   *signature_handler = handler;
 820 }
 821 
 822 
 823 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
 824   if (PrintCompilation && report) {
 825     ttyLocker ttyl;
 826     tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
 827     if (comp_level == CompLevel_all) {
 828       tty->print("all levels ");
 829     } else {
 830       tty->print("levels ");
 831       for (int i = (int)CompLevel_none; i <= comp_level; i++) {
 832         tty->print("%d ", i);
 833       }
 834     }
 835     this->print_short_name(tty);
 836     int size = this->code_size();
 837     if (size > 0) {
 838       tty->print(" (%d bytes)", size);
 839     }
 840     if (reason != NULL) {
 841       tty->print("   %s", reason);
 842     }
 843     tty->cr();
 844   }
 845   if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
 846     ttyLocker ttyl;
 847     xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
 848                      os::current_thread_id(), is_osr, comp_level);
 849     if (reason != NULL) {
 850       xtty->print(" reason=\'%s\'", reason);
 851     }
 852     xtty->method(this);
 853     xtty->stamp();
 854     xtty->end_elem();
 855   }
 856 }
 857 
 858 bool Method::is_always_compilable() const {
 859   // Generated adapters must be compiled
 860   if (is_method_handle_intrinsic() && is_synthetic()) {
 861     assert(!is_not_c1_compilable(), "sanity check");
 862     assert(!is_not_c2_compilable(), "sanity check");
 863     return true;
 864   }
 865 
 866   return false;
 867 }
 868 
 869 bool Method::is_not_compilable(int comp_level) const {
 870   if (number_of_breakpoints() > 0)
 871     return true;
 872   if (is_always_compilable())
 873     return false;
 874   if (comp_level == CompLevel_any)
 875     return is_not_c1_compilable() || is_not_c2_compilable();
 876   if (is_c1_compile(comp_level))
 877     return is_not_c1_compilable();
 878   if (is_c2_compile(comp_level))
 879     return is_not_c2_compilable();
 880   return false;
 881 }
 882 
 883 // call this when compiler finds that this method is not compilable
 884 void Method::set_not_compilable(int comp_level, bool report, const char* reason) {
 885   if (is_always_compilable()) {
 886     // Don't mark a method which should be always compilable
 887     return;
 888   }
 889   print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
 890   if (comp_level == CompLevel_all) {
 891     set_not_c1_compilable();
 892     set_not_c2_compilable();
 893   } else {
 894     if (is_c1_compile(comp_level))
 895       set_not_c1_compilable();
 896     if (is_c2_compile(comp_level))
 897       set_not_c2_compilable();
 898   }
 899   CompilationPolicy::policy()->disable_compilation(this);
 900   assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
 901 }
 902 
 903 bool Method::is_not_osr_compilable(int comp_level) const {
 904   if (is_not_compilable(comp_level))
 905     return true;
 906   if (comp_level == CompLevel_any)
 907     return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
 908   if (is_c1_compile(comp_level))
 909     return is_not_c1_osr_compilable();
 910   if (is_c2_compile(comp_level))
 911     return is_not_c2_osr_compilable();
 912   return false;
 913 }
 914 
 915 void Method::set_not_osr_compilable(int comp_level, bool report, const char* reason) {
 916   print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
 917   if (comp_level == CompLevel_all) {
 918     set_not_c1_osr_compilable();
 919     set_not_c2_osr_compilable();
 920   } else {
 921     if (is_c1_compile(comp_level))
 922       set_not_c1_osr_compilable();
 923     if (is_c2_compile(comp_level))
 924       set_not_c2_osr_compilable();
 925   }
 926   CompilationPolicy::policy()->disable_compilation(this);
 927   assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
 928 }
 929 
 930 // Revert to using the interpreter and clear out the nmethod
 931 void Method::clear_code(bool acquire_lock /* = true */) {
 932   MutexLockerEx pl(acquire_lock ? Patching_lock : NULL, Mutex::_no_safepoint_check_flag);
 933   // this may be NULL if c2i adapters have not been made yet
 934   // Only should happen at allocate time.
 935   if (adapter() == NULL) {
 936     _from_compiled_entry    = NULL;
 937     _from_compiled_value_entry = NULL;
 938     _from_compiled_value_ro_entry = NULL;
 939   } else {
 940     _from_compiled_entry    = adapter()->get_c2i_entry();
 941     _from_compiled_value_entry = adapter()->get_c2i_value_entry();
 942     _from_compiled_value_ro_entry = adapter()->get_c2i_value_ro_entry();
 943   }
 944   OrderAccess::storestore();
 945   _from_interpreted_entry = _i2i_entry;
 946   OrderAccess::storestore();
 947   _code = NULL;
 948 }
 949 
 950 #if INCLUDE_CDS
 951 // Called by class data sharing to remove any entry points (which are not shared)
 952 void Method::unlink_method() {
 953   _code = NULL;
 954 
 955   assert(DumpSharedSpaces, "dump time only");
 956   // Set the values to what they should be at run time. Note that
 957   // this Method can no longer be executed during dump time.
 958   _i2i_entry = Interpreter::entry_for_cds_method(this);
 959   _from_interpreted_entry = _i2i_entry;
 960 
 961   if (is_native()) {
 962     *native_function_addr() = NULL;
 963     set_signature_handler(NULL);
 964   }
 965   NOT_PRODUCT(set_compiled_invocation_count(0);)
 966 
 967   CDSAdapterHandlerEntry* cds_adapter = (CDSAdapterHandlerEntry*)adapter();
 968   constMethod()->set_adapter_trampoline(cds_adapter->get_adapter_trampoline());
 969   _from_compiled_entry = cds_adapter->get_c2i_entry_trampoline();
 970   assert(*((int*)_from_compiled_entry) == 0, "must be NULL during dump time, to be initialized at run time");
 971   _from_compiled_value_entry = cds_adapter->get_c2i_entry_trampoline();
 972   assert(*((int*)_from_compiled_value_entry) == 0, "must be NULL during dump time, to be initialized at run time");
 973   _from_compiled_value_ro_entry = cds_adapter->get_c2i_entry_trampoline();
 974   assert(*((int*)_from_compiled_value_ro_entry) == 0, "must be NULL during dump time, to be initialized at run time");
 975 
 976   set_method_data(NULL);
 977   clear_method_counters();
 978 }
 979 #endif
 980 
 981 /****************************************************************************
 982 // The following illustrates how the entries work for CDS shared Methods:
 983 //
 984 // Our goal is to delay writing into a shared Method until it's compiled.
 985 // Hence, we want to determine the initial values for _i2i_entry,
 986 // _from_interpreted_entry and _from_compiled_entry during CDS dump time.
 987 //
 988 // In this example, both Methods A and B have the _i2i_entry of "zero_locals".
 989 // They also have similar signatures so that they will share the same
 990 // AdapterHandlerEntry.
 991 //
 992 // _adapter_trampoline points to a fixed location in the RW section of
 993 // the CDS archive. This location initially contains a NULL pointer. When the
 994 // first of method A or B is linked, an AdapterHandlerEntry is allocated
 995 // dynamically, and its c2i/i2c entries are generated.
 996 //
 997 // _i2i_entry and _from_interpreted_entry initially points to the same
 998 // (fixed) location in the CODE section of the CDS archive. This contains
 999 // an unconditional branch to the actual entry for "zero_locals", which is
1000 // generated at run time and may be on an arbitrary address. Thus, the
1001 // unconditional branch is also generated at run time to jump to the correct
1002 // address.
1003 //
1004 // Similarly, _from_compiled_entry points to a fixed address in the CODE
1005 // section. This address has enough space for an unconditional branch
1006 // instruction, and is initially zero-filled. After the AdapterHandlerEntry is
1007 // initialized, and the address for the actual c2i_entry is known, we emit a
1008 // branch instruction here to branch to the actual c2i_entry.
1009 //
1010 // The effect of the extra branch on the i2i and c2i entries is negligible.
1011 //
1012 // The reason for putting _adapter_trampoline in RO is many shared Methods
1013 // share the same AdapterHandlerEntry, so we can save space in the RW section
1014 // by having the extra indirection.
1015 
1016 
1017 [Method A: RW]
1018   _constMethod ----> [ConstMethod: RO]
1019                        _adapter_trampoline -----------+
1020                                                       |
1021   _i2i_entry              (same value as method B)    |
1022   _from_interpreted_entry (same value as method B)    |
1023   _from_compiled_entry    (same value as method B)    |
1024                                                       |
1025                                                       |
1026 [Method B: RW]                               +--------+
1027   _constMethod ----> [ConstMethod: RO]       |
1028                        _adapter_trampoline --+--->(AdapterHandlerEntry* ptr: RW)-+
1029                                                                                  |
1030                                                  +-------------------------------+
1031                                                  |
1032                                                  +----> [AdapterHandlerEntry] (allocated at run time)
1033                                                               _fingerprint
1034                                                               _c2i_entry ---------------------------------+->[c2i entry..]
1035  _i2i_entry  -------------+                                   _i2c_entry ---------------+-> [i2c entry..] |
1036  _from_interpreted_entry  |                                   _c2i_unverified_entry     |                 |
1037          |                |                                                             |                 |
1038          |                |  (_cds_entry_table: CODE)                                   |                 |
1039          |                +->[0]: jmp _entry_table[0] --> (i2i_entry_for "zero_locals") |                 |
1040          |                |                               (allocated at run time)       |                 |
1041          |                |  ...                           [asm code ...]               |                 |
1042          +-[not compiled]-+  [n]: jmp _entry_table[n]                                   |                 |
1043          |                                                                              |                 |
1044          |                                                                              |                 |
1045          +-[compiled]-------------------------------------------------------------------+                 |
1046                                                                                                           |
1047  _from_compiled_entry------------>  (_c2i_entry_trampoline: CODE)                                         |
1048                                     [jmp c2i_entry] ------------------------------------------------------+
1049 
1050 ***/
1051 
1052 // Called when the method_holder is getting linked. Setup entrypoints so the method
1053 // is ready to be called from interpreter, compiler, and vtables.
1054 void Method::link_method(const methodHandle& h_method, TRAPS) {
1055   // If the code cache is full, we may reenter this function for the
1056   // leftover methods that weren't linked.
1057   if (is_shared()) {
1058     address entry = Interpreter::entry_for_cds_method(h_method);
1059     assert(entry != NULL && entry == _i2i_entry,
1060            "should be correctly set during dump time");
1061     if (adapter() != NULL) {
1062       return;
1063     }
1064     assert(entry == _from_interpreted_entry,
1065            "should be correctly set during dump time");
1066   } else if (_i2i_entry != NULL) {
1067     return;
1068   }
1069   assert( _code == NULL, "nothing compiled yet" );
1070 
1071   // Setup interpreter entrypoint
1072   assert(this == h_method(), "wrong h_method()" );
1073 
1074   if (!is_shared()) {
1075     assert(adapter() == NULL, "init'd to NULL");
1076     address entry = Interpreter::entry_for_method(h_method);
1077     assert(entry != NULL, "interpreter entry must be non-null");
1078     // Sets both _i2i_entry and _from_interpreted_entry
1079     set_interpreter_entry(entry);
1080   }
1081 
1082   // Don't overwrite already registered native entries.
1083   if (is_native() && !has_native_function()) {
1084     set_native_function(
1085       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1086       !native_bind_event_is_interesting);
1087   }
1088 
1089   // Setup compiler entrypoint.  This is made eagerly, so we do not need
1090   // special handling of vtables.  An alternative is to make adapters more
1091   // lazily by calling make_adapter() from from_compiled_entry() for the
1092   // normal calls.  For vtable calls life gets more complicated.  When a
1093   // call-site goes mega-morphic we need adapters in all methods which can be
1094   // called from the vtable.  We need adapters on such methods that get loaded
1095   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
1096   // problem we'll make these lazily later.
1097   (void) make_adapters(h_method, CHECK);
1098 
1099   // ONLY USE the h_method now as make_adapter may have blocked
1100 
1101 }
1102 
1103 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1104   // Adapters for compiled code are made eagerly here.  They are fairly
1105   // small (generally < 100 bytes) and quick to make (and cached and shared)
1106   // so making them eagerly shouldn't be too expensive.
1107   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1108   if (adapter == NULL ) {
1109     if (!is_init_completed()) {
1110       // Don't throw exceptions during VM initialization because java.lang.* classes
1111       // might not have been initialized, causing problems when constructing the
1112       // Java exception object.
1113       vm_exit_during_initialization("Out of space in CodeCache for adapters");
1114     } else {
1115       THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
1116     }
1117   }
1118 
1119   if (mh->is_shared()) {
1120     assert(mh->adapter() == adapter, "must be");
1121     assert(mh->_from_compiled_entry != NULL, "must be");
1122     assert(mh->_from_compiled_value_entry != NULL, "must be");
1123     assert(mh->_from_compiled_value_ro_entry != NULL, "must be");
1124   } else {
1125     mh->set_adapter_entry(adapter);
1126     mh->_from_compiled_entry = adapter->get_c2i_entry();
1127     mh->_from_compiled_value_entry = adapter->get_c2i_value_entry();
1128     mh->_from_compiled_value_ro_entry = adapter->get_c2i_value_ro_entry();
1129   }
1130   return adapter->get_c2i_entry();
1131 }
1132 
1133 void Method::restore_unshareable_info(TRAPS) {
1134   assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
1135 
1136   // Since restore_unshareable_info can be called more than once for a method, don't
1137   // redo any work.
1138   if (adapter() == NULL) {
1139     methodHandle mh(THREAD, this);
1140     link_method(mh, CHECK);
1141   }
1142 }
1143 
1144 address Method::from_compiled_entry_no_trampoline() const {
1145   CompiledMethod *code = OrderAccess::load_acquire(&_code);
1146   if (code) {
1147     return code->verified_entry_point();
1148   } else {
1149     return adapter()->get_c2i_entry();
1150   }
1151 }
1152 
1153 // The verified_code_entry() must be called when a invoke is resolved
1154 // on this method.
1155 
1156 // It returns the compiled code entry point, after asserting not null.
1157 // This function is called after potential safepoints so that nmethod
1158 // or adapter that it points to is still live and valid.
1159 // This function must not hit a safepoint!
1160 address Method::verified_code_entry() {
1161   debug_only(NoSafepointVerifier nsv;)
1162   assert(_from_compiled_entry != NULL, "must be set");
1163   return _from_compiled_entry;
1164 }
1165 
1166 address Method::verified_value_ro_code_entry() {
1167   debug_only(NoSafepointVerifier nsv;)
1168   assert(_from_compiled_value_ro_entry != NULL, "must be set");
1169   return _from_compiled_value_ro_entry;
1170 }
1171 
1172 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1173 // (could be racing a deopt).
1174 // Not inline to avoid circular ref.
1175 bool Method::check_code() const {
1176   // cached in a register or local.  There's a race on the value of the field.
1177   CompiledMethod *code = OrderAccess::load_acquire(&_code);
1178   return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
1179 }
1180 
1181 // Install compiled code.  Instantly it can execute.
1182 void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
1183   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1184   assert( code, "use clear_code to remove code" );
1185   assert( mh->check_code(), "" );
1186 
1187   guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
1188 
1189   // These writes must happen in this order, because the interpreter will
1190   // directly jump to from_interpreted_entry which jumps to an i2c adapter
1191   // which jumps to _from_compiled_entry.
1192   mh->_code = code;             // Assign before allowing compiled code to exec
1193 
1194   int comp_level = code->comp_level();
1195   // In theory there could be a race here. In practice it is unlikely
1196   // and not worth worrying about.
1197   if (comp_level > mh->highest_comp_level()) {
1198     mh->set_highest_comp_level(comp_level);
1199   }
1200 
1201   OrderAccess::storestore();
1202   mh->_from_compiled_entry = code->verified_entry_point();
1203   mh->_from_compiled_value_entry = code->verified_value_entry_point();
1204   mh->_from_compiled_value_ro_entry = code->verified_value_ro_entry_point();
1205   OrderAccess::storestore();
1206   // Instantly compiled code can execute.
1207   if (!mh->is_method_handle_intrinsic())
1208     mh->_from_interpreted_entry = mh->get_i2c_entry();
1209 }
1210 
1211 
1212 bool Method::is_overridden_in(Klass* k) const {
1213   InstanceKlass* ik = InstanceKlass::cast(k);
1214 
1215   if (ik->is_interface()) return false;
1216 
1217   // If method is an interface, we skip it - except if it
1218   // is a miranda method
1219   if (method_holder()->is_interface()) {
1220     // Check that method is not a miranda method
1221     if (ik->lookup_method(name(), signature()) == NULL) {
1222       // No implementation exist - so miranda method
1223       return false;
1224     }
1225     return true;
1226   }
1227 
1228   assert(ik->is_subclass_of(method_holder()), "should be subklass");
1229   if (!has_vtable_index()) {
1230     return false;
1231   } else {
1232     Method* vt_m = ik->method_at_vtable(vtable_index());
1233     return vt_m != this;
1234   }
1235 }
1236 
1237 
1238 // give advice about whether this Method* should be cached or not
1239 bool Method::should_not_be_cached() const {
1240   if (is_old()) {
1241     // This method has been redefined. It is either EMCP or obsolete
1242     // and we don't want to cache it because that would pin the method
1243     // down and prevent it from being collectible if and when it
1244     // finishes executing.
1245     return true;
1246   }
1247 
1248   // caching this method should be just fine
1249   return false;
1250 }
1251 
1252 
1253 /**
1254  *  Returns true if this is one of the specially treated methods for
1255  *  security related stack walks (like Reflection.getCallerClass).
1256  */
1257 bool Method::is_ignored_by_security_stack_walk() const {
1258   if (intrinsic_id() == vmIntrinsics::_invoke) {
1259     // This is Method.invoke() -- ignore it
1260     return true;
1261   }
1262   if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1263     // This is an auxilary frame -- ignore it
1264     return true;
1265   }
1266   if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1267     // This is an internal adapter frame for method handles -- ignore it
1268     return true;
1269   }
1270   return false;
1271 }
1272 
1273 
1274 // Constant pool structure for invoke methods:
1275 enum {
1276   _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.
1277   _imcp_invoke_signature,       // utf8: (variable Symbol*)
1278   _imcp_limit
1279 };
1280 
1281 // Test if this method is an MH adapter frame generated by Java code.
1282 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1283 bool Method::is_compiled_lambda_form() const {
1284   return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1285 }
1286 
1287 // Test if this method is an internal MH primitive method.
1288 bool Method::is_method_handle_intrinsic() const {
1289   vmIntrinsics::ID iid = intrinsic_id();
1290   return (MethodHandles::is_signature_polymorphic(iid) &&
1291           MethodHandles::is_signature_polymorphic_intrinsic(iid));
1292 }
1293 
1294 bool Method::has_member_arg() const {
1295   vmIntrinsics::ID iid = intrinsic_id();
1296   return (MethodHandles::is_signature_polymorphic(iid) &&
1297           MethodHandles::has_member_arg(iid));
1298 }
1299 
1300 // Make an instance of a signature-polymorphic internal MH primitive.
1301 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1302                                                          Symbol* signature,
1303                                                          TRAPS) {
1304   ResourceMark rm;
1305   methodHandle empty;
1306 
1307   InstanceKlass* holder = SystemDictionary::MethodHandle_klass();
1308   Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1309   assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1310   if (TraceMethodHandles) {
1311     tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1312   }
1313 
1314   // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1315   name->increment_refcount();
1316   signature->increment_refcount();
1317 
1318   int cp_length = _imcp_limit;
1319   ClassLoaderData* loader_data = holder->class_loader_data();
1320   constantPoolHandle cp;
1321   {
1322     ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1323     cp = constantPoolHandle(THREAD, cp_oop);
1324   }
1325   cp->set_pool_holder(holder);
1326   cp->symbol_at_put(_imcp_invoke_name,       name);
1327   cp->symbol_at_put(_imcp_invoke_signature,  signature);
1328   cp->set_has_preresolution();
1329 
1330   // decide on access bits:  public or not?
1331   int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1332   bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1333   if (must_be_static)  flags_bits |= JVM_ACC_STATIC;
1334   assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1335 
1336   methodHandle m;
1337   {
1338     InlineTableSizes sizes;
1339     Method* m_oop = Method::allocate(loader_data, 0,
1340                                      accessFlags_from(flags_bits), &sizes,
1341                                      ConstMethod::NORMAL, CHECK_(empty));
1342     m = methodHandle(THREAD, m_oop);
1343   }
1344   m->set_constants(cp());
1345   m->set_name_index(_imcp_invoke_name);
1346   m->set_signature_index(_imcp_invoke_signature);
1347   assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1348   assert(m->signature() == signature, "");
1349   ResultTypeFinder rtf(signature);
1350   m->constMethod()->set_result_type(rtf.type());
1351   m->compute_size_of_parameters(THREAD);
1352   m->init_intrinsic_id();
1353   assert(m->is_method_handle_intrinsic(), "");
1354 #ifdef ASSERT
1355   if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();
1356   assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1357   assert(m->intrinsic_id() == iid, "correctly predicted iid");
1358 #endif //ASSERT
1359 
1360   // Finally, set up its entry points.
1361   assert(m->can_be_statically_bound(), "");
1362   m->set_vtable_index(Method::nonvirtual_vtable_index);
1363   m->link_method(m, CHECK_(empty));
1364 
1365   if (TraceMethodHandles && (Verbose || WizardMode)) {
1366     ttyLocker ttyl;
1367     m->print_on(tty);
1368   }
1369 
1370   return m;
1371 }
1372 
1373 Klass* Method::check_non_bcp_klass(Klass* klass) {
1374   if (klass != NULL && klass->class_loader() != NULL) {
1375     if (klass->is_objArray_klass())
1376       klass = ObjArrayKlass::cast(klass)->bottom_klass();
1377     return klass;
1378   }
1379   return NULL;
1380 }
1381 
1382 
1383 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1384                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1385   // Code below does not work for native methods - they should never get rewritten anyway
1386   assert(!m->is_native(), "cannot rewrite native methods");
1387   // Allocate new Method*
1388   AccessFlags flags = m->access_flags();
1389 
1390   ConstMethod* cm = m->constMethod();
1391   int checked_exceptions_len = cm->checked_exceptions_length();
1392   int localvariable_len = cm->localvariable_table_length();
1393   int exception_table_len = cm->exception_table_length();
1394   int method_parameters_len = cm->method_parameters_length();
1395   int method_annotations_len = cm->method_annotations_length();
1396   int parameter_annotations_len = cm->parameter_annotations_length();
1397   int type_annotations_len = cm->type_annotations_length();
1398   int default_annotations_len = cm->default_annotations_length();
1399 
1400   InlineTableSizes sizes(
1401       localvariable_len,
1402       new_compressed_linenumber_size,
1403       exception_table_len,
1404       checked_exceptions_len,
1405       method_parameters_len,
1406       cm->generic_signature_index(),
1407       method_annotations_len,
1408       parameter_annotations_len,
1409       type_annotations_len,
1410       default_annotations_len,
1411       0);
1412 
1413   ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1414   Method* newm_oop = Method::allocate(loader_data,
1415                                       new_code_length,
1416                                       flags,
1417                                       &sizes,
1418                                       m->method_type(),
1419                                       CHECK_(methodHandle()));
1420   methodHandle newm (THREAD, newm_oop);
1421 
1422   // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1423   ConstMethod* newcm = newm->constMethod();
1424   int new_const_method_size = newm->constMethod()->size();
1425 
1426   // This works because the source and target are both Methods. Some compilers
1427   // (e.g., clang) complain that the target vtable pointer will be stomped,
1428   // so cast away newm()'s and m()'s Methodness.
1429   memcpy((void*)newm(), (void*)m(), sizeof(Method));
1430 
1431   // Create shallow copy of ConstMethod.
1432   memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1433 
1434   // Reset correct method/const method, method size, and parameter info
1435   newm->set_constMethod(newcm);
1436   newm->constMethod()->set_code_size(new_code_length);
1437   newm->constMethod()->set_constMethod_size(new_const_method_size);
1438   assert(newm->code_size() == new_code_length, "check");
1439   assert(newm->method_parameters_length() == method_parameters_len, "check");
1440   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1441   assert(newm->exception_table_length() == exception_table_len, "check");
1442   assert(newm->localvariable_table_length() == localvariable_len, "check");
1443   // Copy new byte codes
1444   memcpy(newm->code_base(), new_code, new_code_length);
1445   // Copy line number table
1446   if (new_compressed_linenumber_size > 0) {
1447     memcpy(newm->compressed_linenumber_table(),
1448            new_compressed_linenumber_table,
1449            new_compressed_linenumber_size);
1450   }
1451   // Copy method_parameters
1452   if (method_parameters_len > 0) {
1453     memcpy(newm->method_parameters_start(),
1454            m->method_parameters_start(),
1455            method_parameters_len * sizeof(MethodParametersElement));
1456   }
1457   // Copy checked_exceptions
1458   if (checked_exceptions_len > 0) {
1459     memcpy(newm->checked_exceptions_start(),
1460            m->checked_exceptions_start(),
1461            checked_exceptions_len * sizeof(CheckedExceptionElement));
1462   }
1463   // Copy exception table
1464   if (exception_table_len > 0) {
1465     memcpy(newm->exception_table_start(),
1466            m->exception_table_start(),
1467            exception_table_len * sizeof(ExceptionTableElement));
1468   }
1469   // Copy local variable number table
1470   if (localvariable_len > 0) {
1471     memcpy(newm->localvariable_table_start(),
1472            m->localvariable_table_start(),
1473            localvariable_len * sizeof(LocalVariableTableElement));
1474   }
1475   // Copy stackmap table
1476   if (m->has_stackmap_table()) {
1477     int code_attribute_length = m->stackmap_data()->length();
1478     Array<u1>* stackmap_data =
1479       MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1480     memcpy((void*)stackmap_data->adr_at(0),
1481            (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1482     newm->set_stackmap_data(stackmap_data);
1483   }
1484 
1485   // copy annotations over to new method
1486   newcm->copy_annotations_from(loader_data, cm, CHECK_NULL);
1487   return newm;
1488 }
1489 
1490 vmSymbols::SID Method::klass_id_for_intrinsics(const Klass* holder) {
1491   // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1492   // because we are not loading from core libraries
1493   // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1494   // which does not use the class default class loader so we check for its loader here
1495   const InstanceKlass* ik = InstanceKlass::cast(holder);
1496   if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1497     return vmSymbols::NO_SID;   // regardless of name, no intrinsics here
1498   }
1499 
1500   // see if the klass name is well-known:
1501   Symbol* klass_name = ik->name();
1502   return vmSymbols::find_sid(klass_name);
1503 }
1504 
1505 void Method::init_intrinsic_id() {
1506   assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1507   const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1508   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1509   assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1510 
1511   // the klass name is well-known:
1512   vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1513   assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1514 
1515   // ditto for method and signature:
1516   vmSymbols::SID  name_id = vmSymbols::find_sid(name());
1517   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1518       && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1519       && name_id == vmSymbols::NO_SID) {
1520     return;
1521   }
1522   vmSymbols::SID   sig_id = vmSymbols::find_sid(signature());
1523   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1524       && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1525       && sig_id == vmSymbols::NO_SID) {
1526     return;
1527   }
1528   jshort flags = access_flags().as_short();
1529 
1530   vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1531   if (id != vmIntrinsics::_none) {
1532     set_intrinsic_id(id);
1533     if (id == vmIntrinsics::_Class_cast) {
1534       // Even if the intrinsic is rejected, we want to inline this simple method.
1535       set_force_inline(true);
1536     }
1537     return;
1538   }
1539 
1540   // A few slightly irregular cases:
1541   switch (klass_id) {
1542   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1543     // Second chance: check in regular Math.
1544     switch (name_id) {
1545     case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1546     case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1547     case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1548       // pretend it is the corresponding method in the non-strict class:
1549       klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1550       id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1551       break;
1552     default:
1553       break;
1554     }
1555     break;
1556 
1557   // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1558   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1559   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1560     if (!is_native())  break;
1561     id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1562     if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1563       id = vmIntrinsics::_none;
1564     break;
1565 
1566   default:
1567     break;
1568   }
1569 
1570   if (id != vmIntrinsics::_none) {
1571     // Set up its iid.  It is an alias method.
1572     set_intrinsic_id(id);
1573     return;
1574   }
1575 }
1576 
1577 // These two methods are static since a GC may move the Method
1578 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1579   if (!THREAD->can_call_java()) {
1580     // There is nothing useful this routine can do from within the Compile thread.
1581     // Hopefully, the signature contains only well-known classes.
1582     // We could scan for this and return true/false, but the caller won't care.
1583     return false;
1584   }
1585   bool sig_is_loaded = true;
1586   Handle class_loader(THREAD, m->method_holder()->class_loader());
1587   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1588   ResourceMark rm(THREAD);
1589   Symbol*  signature = m->signature();
1590   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1591     if (ss.is_object()) {
1592       Symbol* sym = ss.as_symbol(CHECK_(false));
1593       Symbol*  name  = sym;
1594       Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1595                                              protection_domain, THREAD);
1596       // We are loading classes eagerly. If a ClassNotFoundException or
1597       // a LinkageError was generated, be sure to ignore it.
1598       if (HAS_PENDING_EXCEPTION) {
1599         if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1600             PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1601           CLEAR_PENDING_EXCEPTION;
1602         } else {
1603           return false;
1604         }
1605       }
1606       if( klass == NULL) { sig_is_loaded = false; }
1607     }
1608   }
1609   return sig_is_loaded;
1610 }
1611 
1612 bool Method::has_unloaded_classes_in_signature(const methodHandle& m, TRAPS) {
1613   Handle class_loader(THREAD, m->method_holder()->class_loader());
1614   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1615   ResourceMark rm(THREAD);
1616   Symbol*  signature = m->signature();
1617   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1618     if (ss.type() == T_OBJECT) {
1619       Symbol* name = ss.as_symbol_or_null();
1620       if (name == NULL) return true;
1621       Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1622       if (klass == NULL) return true;
1623     }
1624   }
1625   return false;
1626 }
1627 
1628 // Exposed so field engineers can debug VM
1629 void Method::print_short_name(outputStream* st) {
1630   ResourceMark rm;
1631 #ifdef PRODUCT
1632   st->print(" %s::", method_holder()->external_name());
1633 #else
1634   st->print(" %s::", method_holder()->internal_name());
1635 #endif
1636   name()->print_symbol_on(st);
1637   if (WizardMode) signature()->print_symbol_on(st);
1638   else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1639     MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1640 }
1641 
1642 // Comparer for sorting an object array containing
1643 // Method*s.
1644 static int method_comparator(Method* a, Method* b) {
1645   return a->name()->fast_compare(b->name());
1646 }
1647 
1648 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1649 // default_methods also uses this without the ordering for fast find_method
1650 void Method::sort_methods(Array<Method*>* methods, bool set_idnums) {
1651   int length = methods->length();
1652   if (length > 1) {
1653     {
1654       NoSafepointVerifier nsv;
1655       QuickSort::sort(methods->data(), length, method_comparator, /*idempotent=*/false);
1656     }
1657     // Reset method ordering
1658     if (set_idnums) {
1659       for (int i = 0; i < length; i++) {
1660         Method* m = methods->at(i);
1661         m->set_method_idnum(i);
1662         m->set_orig_method_idnum(i);
1663       }
1664     }
1665   }
1666 }
1667 
1668 //-----------------------------------------------------------------------------------
1669 // Non-product code unless JVM/TI needs it
1670 
1671 #if !defined(PRODUCT) || INCLUDE_JVMTI
1672 class SignatureTypePrinter : public SignatureTypeNames {
1673  private:
1674   outputStream* _st;
1675   bool _use_separator;
1676 
1677   void type_name(const char* name) {
1678     if (_use_separator) _st->print(", ");
1679     _st->print("%s", name);
1680     _use_separator = true;
1681   }
1682 
1683  public:
1684   SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1685     _st = st;
1686     _use_separator = false;
1687   }
1688 
1689   void print_parameters()              { _use_separator = false; iterate_parameters(); }
1690   void print_returntype()              { _use_separator = false; iterate_returntype(); }
1691 };
1692 
1693 
1694 void Method::print_name(outputStream* st) {
1695   Thread *thread = Thread::current();
1696   ResourceMark rm(thread);
1697   st->print("%s ", is_static() ? "static" : "virtual");
1698   if (WizardMode) {
1699     st->print("%s.", method_holder()->internal_name());
1700     name()->print_symbol_on(st);
1701     signature()->print_symbol_on(st);
1702   } else {
1703     SignatureTypePrinter sig(signature(), st);
1704     sig.print_returntype();
1705     st->print(" %s.", method_holder()->internal_name());
1706     name()->print_symbol_on(st);
1707     st->print("(");
1708     sig.print_parameters();
1709     st->print(")");
1710   }
1711 }
1712 #endif // !PRODUCT || INCLUDE_JVMTI
1713 
1714 
1715 void Method::print_codes_on(outputStream* st) const {
1716   print_codes_on(0, code_size(), st);
1717 }
1718 
1719 void Method::print_codes_on(int from, int to, outputStream* st) const {
1720   Thread *thread = Thread::current();
1721   ResourceMark rm(thread);
1722   methodHandle mh (thread, (Method*)this);
1723   BytecodeStream s(mh);
1724   s.set_interval(from, to);
1725   BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1726   while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1727 }
1728 
1729 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1730   _bci = 0;
1731   _line = 0;
1732 };
1733 
1734 bool CompressedLineNumberReadStream::read_pair() {
1735   jubyte next = read_byte();
1736   // Check for terminator
1737   if (next == 0) return false;
1738   if (next == 0xFF) {
1739     // Escape character, regular compression used
1740     _bci  += read_signed_int();
1741     _line += read_signed_int();
1742   } else {
1743     // Single byte compression used
1744     _bci  += next >> 3;
1745     _line += next & 0x7;
1746   }
1747   return true;
1748 }
1749 
1750 #if INCLUDE_JVMTI
1751 
1752 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1753   BreakpointInfo* bp = method_holder()->breakpoints();
1754   for (; bp != NULL; bp = bp->next()) {
1755     if (bp->match(this, bci)) {
1756       return bp->orig_bytecode();
1757     }
1758   }
1759   {
1760     ResourceMark rm;
1761     fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1762   }
1763   return Bytecodes::_shouldnotreachhere;
1764 }
1765 
1766 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1767   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1768   BreakpointInfo* bp = method_holder()->breakpoints();
1769   for (; bp != NULL; bp = bp->next()) {
1770     if (bp->match(this, bci)) {
1771       bp->set_orig_bytecode(code);
1772       // and continue, in case there is more than one
1773     }
1774   }
1775 }
1776 
1777 void Method::set_breakpoint(int bci) {
1778   InstanceKlass* ik = method_holder();
1779   BreakpointInfo *bp = new BreakpointInfo(this, bci);
1780   bp->set_next(ik->breakpoints());
1781   ik->set_breakpoints(bp);
1782   // do this last:
1783   bp->set(this);
1784 }
1785 
1786 static void clear_matches(Method* m, int bci) {
1787   InstanceKlass* ik = m->method_holder();
1788   BreakpointInfo* prev_bp = NULL;
1789   BreakpointInfo* next_bp;
1790   for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1791     next_bp = bp->next();
1792     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1793     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1794       // do this first:
1795       bp->clear(m);
1796       // unhook it
1797       if (prev_bp != NULL)
1798         prev_bp->set_next(next_bp);
1799       else
1800         ik->set_breakpoints(next_bp);
1801       delete bp;
1802       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1803       // at same location. So we have multiple matching (method_index and bci)
1804       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1805       // breakpoint for clear_breakpoint request and keep all other method versions
1806       // BreakpointInfo for future clear_breakpoint request.
1807       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1808       // which is being called when class is unloaded. We delete all the Breakpoint
1809       // information for all versions of method. We may not correctly restore the original
1810       // bytecode in all method versions, but that is ok. Because the class is being unloaded
1811       // so these methods won't be used anymore.
1812       if (bci >= 0) {
1813         break;
1814       }
1815     } else {
1816       // This one is a keeper.
1817       prev_bp = bp;
1818     }
1819   }
1820 }
1821 
1822 void Method::clear_breakpoint(int bci) {
1823   assert(bci >= 0, "");
1824   clear_matches(this, bci);
1825 }
1826 
1827 void Method::clear_all_breakpoints() {
1828   clear_matches(this, -1);
1829 }
1830 
1831 #endif // INCLUDE_JVMTI
1832 
1833 int Method::invocation_count() {
1834   MethodCounters *mcs = method_counters();
1835   if (TieredCompilation) {
1836     MethodData* const mdo = method_data();
1837     if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1838         ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1839       return InvocationCounter::count_limit;
1840     } else {
1841       return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1842              ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1843     }
1844   } else {
1845     return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1846   }
1847 }
1848 
1849 int Method::backedge_count() {
1850   MethodCounters *mcs = method_counters();
1851   if (TieredCompilation) {
1852     MethodData* const mdo = method_data();
1853     if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1854         ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1855       return InvocationCounter::count_limit;
1856     } else {
1857       return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1858              ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1859     }
1860   } else {
1861     return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1862   }
1863 }
1864 
1865 int Method::highest_comp_level() const {
1866   const MethodCounters* mcs = method_counters();
1867   if (mcs != NULL) {
1868     return mcs->highest_comp_level();
1869   } else {
1870     return CompLevel_none;
1871   }
1872 }
1873 
1874 int Method::highest_osr_comp_level() const {
1875   const MethodCounters* mcs = method_counters();
1876   if (mcs != NULL) {
1877     return mcs->highest_osr_comp_level();
1878   } else {
1879     return CompLevel_none;
1880   }
1881 }
1882 
1883 void Method::set_highest_comp_level(int level) {
1884   MethodCounters* mcs = method_counters();
1885   if (mcs != NULL) {
1886     mcs->set_highest_comp_level(level);
1887   }
1888 }
1889 
1890 void Method::set_highest_osr_comp_level(int level) {
1891   MethodCounters* mcs = method_counters();
1892   if (mcs != NULL) {
1893     mcs->set_highest_osr_comp_level(level);
1894   }
1895 }
1896 
1897 #if INCLUDE_JVMTI
1898 
1899 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1900   _bci = bci;
1901   _name_index = m->name_index();
1902   _signature_index = m->signature_index();
1903   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1904   if (_orig_bytecode == Bytecodes::_breakpoint)
1905     _orig_bytecode = m->orig_bytecode_at(_bci);
1906   _next = NULL;
1907 }
1908 
1909 void BreakpointInfo::set(Method* method) {
1910 #ifdef ASSERT
1911   {
1912     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
1913     if (code == Bytecodes::_breakpoint)
1914       code = method->orig_bytecode_at(_bci);
1915     assert(orig_bytecode() == code, "original bytecode must be the same");
1916   }
1917 #endif
1918   Thread *thread = Thread::current();
1919   *method->bcp_from(_bci) = Bytecodes::_breakpoint;
1920   method->incr_number_of_breakpoints(thread);
1921   SystemDictionary::notice_modification();
1922   {
1923     // Deoptimize all dependents on this method
1924     HandleMark hm(thread);
1925     methodHandle mh(thread, method);
1926     CodeCache::flush_dependents_on_method(mh);
1927   }
1928 }
1929 
1930 void BreakpointInfo::clear(Method* method) {
1931   *method->bcp_from(_bci) = orig_bytecode();
1932   assert(method->number_of_breakpoints() > 0, "must not go negative");
1933   method->decr_number_of_breakpoints(Thread::current());
1934 }
1935 
1936 #endif // INCLUDE_JVMTI
1937 
1938 // jmethodID handling
1939 
1940 // This is a block allocating object, sort of like JNIHandleBlock, only a
1941 // lot simpler.
1942 // It's allocated on the CHeap because once we allocate a jmethodID, we can
1943 // never get rid of it.
1944 
1945 static const int min_block_size = 8;
1946 
1947 class JNIMethodBlockNode : public CHeapObj<mtClass> {
1948   friend class JNIMethodBlock;
1949   Method**        _methods;
1950   int             _number_of_methods;
1951   int             _top;
1952   JNIMethodBlockNode* _next;
1953 
1954  public:
1955 
1956   JNIMethodBlockNode(int num_methods = min_block_size);
1957 
1958   ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
1959 
1960   void ensure_methods(int num_addl_methods) {
1961     if (_top < _number_of_methods) {
1962       num_addl_methods -= _number_of_methods - _top;
1963       if (num_addl_methods <= 0) {
1964         return;
1965       }
1966     }
1967     if (_next == NULL) {
1968       _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
1969     } else {
1970       _next->ensure_methods(num_addl_methods);
1971     }
1972   }
1973 };
1974 
1975 class JNIMethodBlock : public CHeapObj<mtClass> {
1976   JNIMethodBlockNode _head;
1977   JNIMethodBlockNode *_last_free;
1978  public:
1979   static Method* const _free_method;
1980 
1981   JNIMethodBlock(int initial_capacity = min_block_size)
1982       : _head(initial_capacity), _last_free(&_head) {}
1983 
1984   void ensure_methods(int num_addl_methods) {
1985     _last_free->ensure_methods(num_addl_methods);
1986   }
1987 
1988   Method** add_method(Method* m) {
1989     for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
1990       if (b->_top < b->_number_of_methods) {
1991         // top points to the next free entry.
1992         int i = b->_top;
1993         b->_methods[i] = m;
1994         b->_top++;
1995         _last_free = b;
1996         return &(b->_methods[i]);
1997       } else if (b->_top == b->_number_of_methods) {
1998         // if the next free entry ran off the block see if there's a free entry
1999         for (int i = 0; i < b->_number_of_methods; i++) {
2000           if (b->_methods[i] == _free_method) {
2001             b->_methods[i] = m;
2002             _last_free = b;
2003             return &(b->_methods[i]);
2004           }
2005         }
2006         // Only check each block once for frees.  They're very unlikely.
2007         // Increment top past the end of the block.
2008         b->_top++;
2009       }
2010       // need to allocate a next block.
2011       if (b->_next == NULL) {
2012         b->_next = _last_free = new JNIMethodBlockNode();
2013       }
2014     }
2015     guarantee(false, "Should always allocate a free block");
2016     return NULL;
2017   }
2018 
2019   bool contains(Method** m) {
2020     if (m == NULL) return false;
2021     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2022       if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2023         // This is a bit of extra checking, for two reasons.  One is
2024         // that contains() deals with pointers that are passed in by
2025         // JNI code, so making sure that the pointer is aligned
2026         // correctly is valuable.  The other is that <= and > are
2027         // technically not defined on pointers, so the if guard can
2028         // pass spuriously; no modern compiler is likely to make that
2029         // a problem, though (and if one did, the guard could also
2030         // fail spuriously, which would be bad).
2031         ptrdiff_t idx = m - b->_methods;
2032         if (b->_methods + idx == m) {
2033           return true;
2034         }
2035       }
2036     }
2037     return false;  // not found
2038   }
2039 
2040   // Doesn't really destroy it, just marks it as free so it can be reused.
2041   void destroy_method(Method** m) {
2042 #ifdef ASSERT
2043     assert(contains(m), "should be a methodID");
2044 #endif // ASSERT
2045     *m = _free_method;
2046   }
2047 
2048   // During class unloading the methods are cleared, which is different
2049   // than freed.
2050   void clear_all_methods() {
2051     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2052       for (int i = 0; i< b->_number_of_methods; i++) {
2053         b->_methods[i] = NULL;
2054       }
2055     }
2056   }
2057 #ifndef PRODUCT
2058   int count_methods() {
2059     // count all allocated methods
2060     int count = 0;
2061     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2062       for (int i = 0; i< b->_number_of_methods; i++) {
2063         if (b->_methods[i] != _free_method) count++;
2064       }
2065     }
2066     return count;
2067   }
2068 #endif // PRODUCT
2069 };
2070 
2071 // Something that can't be mistaken for an address or a markOop
2072 Method* const JNIMethodBlock::_free_method = (Method*)55;
2073 
2074 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(NULL) {
2075   _number_of_methods = MAX2(num_methods, min_block_size);
2076   _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2077   for (int i = 0; i < _number_of_methods; i++) {
2078     _methods[i] = JNIMethodBlock::_free_method;
2079   }
2080 }
2081 
2082 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
2083   ClassLoaderData* cld = loader_data;
2084   if (!SafepointSynchronize::is_at_safepoint()) {
2085     // Have to add jmethod_ids() to class loader data thread-safely.
2086     // Also have to add the method to the list safely, which the cld lock
2087     // protects as well.
2088     MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
2089     if (cld->jmethod_ids() == NULL) {
2090       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2091     } else {
2092       cld->jmethod_ids()->ensure_methods(capacity);
2093     }
2094   } else {
2095     // At safepoint, we are single threaded and can set this.
2096     if (cld->jmethod_ids() == NULL) {
2097       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2098     } else {
2099       cld->jmethod_ids()->ensure_methods(capacity);
2100     }
2101   }
2102 }
2103 
2104 // Add a method id to the jmethod_ids
2105 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
2106   ClassLoaderData* cld = loader_data;
2107 
2108   if (!SafepointSynchronize::is_at_safepoint()) {
2109     // Have to add jmethod_ids() to class loader data thread-safely.
2110     // Also have to add the method to the list safely, which the cld lock
2111     // protects as well.
2112     MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
2113     if (cld->jmethod_ids() == NULL) {
2114       cld->set_jmethod_ids(new JNIMethodBlock());
2115     }
2116     // jmethodID is a pointer to Method*
2117     return (jmethodID)cld->jmethod_ids()->add_method(m);
2118   } else {
2119     // At safepoint, we are single threaded and can set this.
2120     if (cld->jmethod_ids() == NULL) {
2121       cld->set_jmethod_ids(new JNIMethodBlock());
2122     }
2123     // jmethodID is a pointer to Method*
2124     return (jmethodID)cld->jmethod_ids()->add_method(m);
2125   }
2126 }
2127 
2128 // Mark a jmethodID as free.  This is called when there is a data race in
2129 // InstanceKlass while creating the jmethodID cache.
2130 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
2131   ClassLoaderData* cld = loader_data;
2132   Method** ptr = (Method**)m;
2133   assert(cld->jmethod_ids() != NULL, "should have method handles");
2134   cld->jmethod_ids()->destroy_method(ptr);
2135 }
2136 
2137 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2138   // Can't assert the method_holder is the same because the new method has the
2139   // scratch method holder.
2140   assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2141            == new_method->method_holder()->class_loader() ||
2142            new_method->method_holder()->class_loader() == NULL, // allow Unsafe substitution
2143          "changing to a different class loader");
2144   // Just change the method in place, jmethodID pointer doesn't change.
2145   *((Method**)jmid) = new_method;
2146 }
2147 
2148 bool Method::is_method_id(jmethodID mid) {
2149   Method* m = resolve_jmethod_id(mid);
2150   assert(m != NULL, "should be called with non-null method");
2151   InstanceKlass* ik = m->method_holder();
2152   ClassLoaderData* cld = ik->class_loader_data();
2153   if (cld->jmethod_ids() == NULL) return false;
2154   return (cld->jmethod_ids()->contains((Method**)mid));
2155 }
2156 
2157 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2158   if (mid == NULL) return NULL;
2159   Method* o = resolve_jmethod_id(mid);
2160   if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
2161     return NULL;
2162   }
2163   return o;
2164 };
2165 
2166 void Method::set_on_stack(const bool value) {
2167   // Set both the method itself and its constant pool.  The constant pool
2168   // on stack means some method referring to it is also on the stack.
2169   constants()->set_on_stack(value);
2170 
2171   bool already_set = on_stack();
2172   _access_flags.set_on_stack(value);
2173   if (value && !already_set) {
2174     MetadataOnStackMark::record(this);
2175   }
2176   assert(!value || !is_old() || is_obsolete() || is_running_emcp(),
2177          "emcp methods cannot run after emcp bit is cleared");
2178 }
2179 
2180 // Called when the class loader is unloaded to make all methods weak.
2181 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2182   loader_data->jmethod_ids()->clear_all_methods();
2183 }
2184 
2185 bool Method::has_method_vptr(const void* ptr) {
2186   Method m;
2187   // This assumes that the vtbl pointer is the first word of a C++ object.
2188   return dereference_vptr(&m) == dereference_vptr(ptr);
2189 }
2190 
2191 // Check that this pointer is valid by checking that the vtbl pointer matches
2192 bool Method::is_valid_method(const Method* m) {
2193   if (m == NULL) {
2194     return false;
2195   } else if ((intptr_t(m) & (wordSize-1)) != 0) {
2196     // Quick sanity check on pointer.
2197     return false;
2198   } else if (m->is_shared()) {
2199     return MetaspaceShared::is_valid_shared_method(m);
2200   } else if (Metaspace::contains_non_shared(m)) {
2201     return has_method_vptr((const void*)m);
2202   } else {
2203     return false;
2204   }
2205 }
2206 
2207 #ifndef PRODUCT
2208 void Method::print_jmethod_ids(const ClassLoaderData* loader_data, outputStream* out) {
2209   out->print(" jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2210 }
2211 #endif // PRODUCT
2212 
2213 
2214 // Printing
2215 
2216 #ifndef PRODUCT
2217 
2218 void Method::print_on(outputStream* st) const {
2219   ResourceMark rm;
2220   assert(is_method(), "must be method");
2221   st->print_cr("%s", internal_name());
2222   st->print_cr(" - this oop:          " INTPTR_FORMAT, p2i(this));
2223   st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();
2224   st->print   (" - constants:         " INTPTR_FORMAT " ", p2i(constants()));
2225   constants()->print_value_on(st); st->cr();
2226   st->print   (" - access:            0x%x  ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2227   st->print   (" - name:              ");    name()->print_value_on(st); st->cr();
2228   st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();
2229   st->print_cr(" - max stack:         %d",   max_stack());
2230   st->print_cr(" - max locals:        %d",   max_locals());
2231   st->print_cr(" - size of params:    %d",   size_of_parameters());
2232   st->print_cr(" - method size:       %d",   method_size());
2233   if (intrinsic_id() != vmIntrinsics::_none)
2234     st->print_cr(" - intrinsic id:      %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
2235   if (highest_comp_level() != CompLevel_none)
2236     st->print_cr(" - highest level:     %d", highest_comp_level());
2237   st->print_cr(" - vtable index:      %d",   _vtable_index);
2238   if (valid_itable_index())
2239     st->print_cr(" - itable index:      %d",   itable_index());
2240   st->print_cr(" - i2i entry:         " INTPTR_FORMAT, p2i(interpreter_entry()));
2241   st->print(   " - adapters:          ");
2242   AdapterHandlerEntry* a = ((Method*)this)->adapter();
2243   if (a == NULL)
2244     st->print_cr(INTPTR_FORMAT, p2i(a));
2245   else
2246     a->print_adapter_on(st);
2247   st->print_cr(" - compiled entry     " INTPTR_FORMAT, p2i(from_compiled_entry()));
2248   st->print_cr(" - code size:         %d",   code_size());
2249   if (code_size() != 0) {
2250     st->print_cr(" - code start:        " INTPTR_FORMAT, p2i(code_base()));
2251     st->print_cr(" - code end (excl):   " INTPTR_FORMAT, p2i(code_base() + code_size()));
2252   }
2253   if (method_data() != NULL) {
2254     st->print_cr(" - method data:       " INTPTR_FORMAT, p2i(method_data()));
2255   }
2256   st->print_cr(" - checked ex length: %d",   checked_exceptions_length());
2257   if (checked_exceptions_length() > 0) {
2258     CheckedExceptionElement* table = checked_exceptions_start();
2259     st->print_cr(" - checked ex start:  " INTPTR_FORMAT, p2i(table));
2260     if (Verbose) {
2261       for (int i = 0; i < checked_exceptions_length(); i++) {
2262         st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2263       }
2264     }
2265   }
2266   if (has_linenumber_table()) {
2267     u_char* table = compressed_linenumber_table();
2268     st->print_cr(" - linenumber start:  " INTPTR_FORMAT, p2i(table));
2269     if (Verbose) {
2270       CompressedLineNumberReadStream stream(table);
2271       while (stream.read_pair()) {
2272         st->print_cr("   - line %d: %d", stream.line(), stream.bci());
2273       }
2274     }
2275   }
2276   st->print_cr(" - localvar length:   %d",   localvariable_table_length());
2277   if (localvariable_table_length() > 0) {
2278     LocalVariableTableElement* table = localvariable_table_start();
2279     st->print_cr(" - localvar start:    " INTPTR_FORMAT, p2i(table));
2280     if (Verbose) {
2281       for (int i = 0; i < localvariable_table_length(); i++) {
2282         int bci = table[i].start_bci;
2283         int len = table[i].length;
2284         const char* name = constants()->printable_name_at(table[i].name_cp_index);
2285         const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2286         int slot = table[i].slot;
2287         st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2288       }
2289     }
2290   }
2291   if (code() != NULL) {
2292     st->print   (" - compiled code: ");
2293     code()->print_value_on(st);
2294   }
2295   if (is_native()) {
2296     st->print_cr(" - native function:   " INTPTR_FORMAT, p2i(native_function()));
2297     st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2298   }
2299 }
2300 
2301 void Method::print_linkage_flags(outputStream* st) {
2302   access_flags().print_on(st);
2303   if (is_default_method()) {
2304     st->print("default ");
2305   }
2306   if (is_overpass()) {
2307     st->print("overpass ");
2308   }
2309 }
2310 #endif //PRODUCT
2311 
2312 void Method::print_value_on(outputStream* st) const {
2313   assert(is_method(), "must be method");
2314   st->print("%s", internal_name());
2315   print_address_on(st);
2316   st->print(" ");
2317   if (WizardMode) access_flags().print_on(st);
2318   name()->print_value_on(st);
2319   st->print(" ");
2320   signature()->print_value_on(st);
2321   st->print(" in ");
2322   method_holder()->print_value_on(st);
2323   if (WizardMode) st->print("#%d", _vtable_index);
2324   if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2325   if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2326 }
2327 
2328 #if INCLUDE_SERVICES
2329 // Size Statistics
2330 void Method::collect_statistics(KlassSizeStats *sz) const {
2331   int mysize = sz->count(this);
2332   sz->_method_bytes += mysize;
2333   sz->_method_all_bytes += mysize;
2334   sz->_rw_bytes += mysize;
2335 
2336   if (constMethod()) {
2337     constMethod()->collect_statistics(sz);
2338   }
2339   if (method_data()) {
2340     method_data()->collect_statistics(sz);
2341   }
2342 }
2343 #endif // INCLUDE_SERVICES
2344 
2345 // LogTouchedMethods and PrintTouchedMethods
2346 
2347 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2348 // the Method may be garbage collected. Let's roll our own hash table.
2349 class TouchedMethodRecord : CHeapObj<mtTracing> {
2350 public:
2351   // It's OK to store Symbols here because they will NOT be GC'ed if
2352   // LogTouchedMethods is enabled.
2353   TouchedMethodRecord* _next;
2354   Symbol* _class_name;
2355   Symbol* _method_name;
2356   Symbol* _method_signature;
2357 };
2358 
2359 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2360 static TouchedMethodRecord** _touched_method_table = NULL;
2361 
2362 void Method::log_touched(TRAPS) {
2363 
2364   const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2365   Symbol* my_class = klass_name();
2366   Symbol* my_name  = name();
2367   Symbol* my_sig   = signature();
2368 
2369   unsigned int hash = my_class->identity_hash() +
2370                       my_name->identity_hash() +
2371                       my_sig->identity_hash();
2372   juint index = juint(hash) % table_size;
2373 
2374   MutexLocker ml(TouchedMethodLog_lock, THREAD);
2375   if (_touched_method_table == NULL) {
2376     _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2377                                               mtTracing, CURRENT_PC);
2378     memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2379   }
2380 
2381   TouchedMethodRecord* ptr = _touched_method_table[index];
2382   while (ptr) {
2383     if (ptr->_class_name       == my_class &&
2384         ptr->_method_name      == my_name &&
2385         ptr->_method_signature == my_sig) {
2386       return;
2387     }
2388     if (ptr->_next == NULL) break;
2389     ptr = ptr->_next;
2390   }
2391   TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2392   my_class->increment_refcount();
2393   my_name->increment_refcount();
2394   my_sig->increment_refcount();
2395   nptr->_class_name         = my_class;
2396   nptr->_method_name        = my_name;
2397   nptr->_method_signature   = my_sig;
2398   nptr->_next               = NULL;
2399 
2400   if (ptr == NULL) {
2401     // first
2402     _touched_method_table[index] = nptr;
2403   } else {
2404     ptr->_next = nptr;
2405   }
2406 }
2407 
2408 void Method::print_touched_methods(outputStream* out) {
2409   MutexLockerEx ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2410   out->print_cr("# Method::print_touched_methods version 1");
2411   if (_touched_method_table) {
2412     for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2413       TouchedMethodRecord* ptr = _touched_method_table[i];
2414       while(ptr) {
2415         ptr->_class_name->print_symbol_on(out);       out->print(".");
2416         ptr->_method_name->print_symbol_on(out);      out->print(":");
2417         ptr->_method_signature->print_symbol_on(out); out->cr();
2418         ptr = ptr->_next;
2419       }
2420     }
2421   }
2422 }
2423 
2424 // Verification
2425 
2426 void Method::verify_on(outputStream* st) {
2427   guarantee(is_method(), "object must be method");
2428   guarantee(constants()->is_constantPool(), "should be constant pool");
2429   MethodData* md = method_data();
2430   guarantee(md == NULL ||
2431       md->is_methodData(), "should be method data");
2432 }