1 /*
   2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/metadataOnStackMark.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "code/codeCache.hpp"
  29 #include "code/debugInfoRec.hpp"
  30 #include "gc/shared/collectedHeap.inline.hpp"
  31 #include "gc/shared/gcLocker.hpp"
  32 #include "gc/shared/generation.hpp"
  33 #include "interpreter/bytecodeStream.hpp"
  34 #include "interpreter/bytecodeTracer.hpp"
  35 #include "interpreter/bytecodes.hpp"
  36 #include "interpreter/interpreter.hpp"
  37 #include "interpreter/oopMapCache.hpp"
  38 #include "memory/heapInspection.hpp"
  39 #include "memory/metadataFactory.hpp"
  40 #include "memory/oopFactory.hpp"
  41 #include "oops/constMethod.hpp"
  42 #include "oops/method.hpp"
  43 #include "oops/methodData.hpp"
  44 #include "oops/oop.inline.hpp"
  45 #include "oops/symbol.hpp"
  46 #include "prims/jvmtiExport.hpp"
  47 #include "prims/methodHandles.hpp"
  48 #include "prims/nativeLookup.hpp"
  49 #include "runtime/arguments.hpp"
  50 #include "runtime/compilationPolicy.hpp"
  51 #include "runtime/frame.inline.hpp"
  52 #include "runtime/handles.inline.hpp"
  53 #include "runtime/orderAccess.inline.hpp"
  54 #include "runtime/relocator.hpp"
  55 #include "runtime/sharedRuntime.hpp"
  56 #include "runtime/signature.hpp"
  57 #include "utilities/quickSort.hpp"
  58 #include "utilities/xmlstream.hpp"
  59 
  60 // Implementation of Method
  61 
  62 Method* Method::allocate(ClassLoaderData* loader_data,
  63                          int byte_code_size,
  64                          AccessFlags access_flags,
  65                          InlineTableSizes* sizes,
  66                          ConstMethod::MethodType method_type,
  67                          TRAPS) {
  68   assert(!access_flags.is_native() || byte_code_size == 0,
  69          "native methods should not contain byte codes");
  70   ConstMethod* cm = ConstMethod::allocate(loader_data,
  71                                           byte_code_size,
  72                                           sizes,
  73                                           method_type,
  74                                           CHECK_NULL);
  75   int size = Method::size(access_flags.is_native());
  76   return new (loader_data, size, false, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
  77 }
  78 
  79 Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
  80   No_Safepoint_Verifier no_safepoint;
  81   set_constMethod(xconst);
  82   set_access_flags(access_flags);
  83 #ifdef CC_INTERP
  84   set_result_index(T_VOID);
  85 #endif
  86   set_intrinsic_id(vmIntrinsics::_none);
  87   set_jfr_towrite(false);
  88   set_force_inline(false);
  89   set_hidden(false);
  90   set_dont_inline(false);
  91   set_has_injected_profile(false);
  92   set_method_data(NULL);
  93   clear_method_counters();
  94   set_vtable_index(Method::garbage_vtable_index);
  95 
  96   // Fix and bury in Method*
  97   set_interpreter_entry(NULL); // sets i2i entry and from_int
  98   set_adapter_entry(NULL);
  99   clear_code(); // from_c/from_i get set to c2i/i2i
 100 
 101   if (access_flags.is_native()) {
 102     clear_native_function();
 103     set_signature_handler(NULL);
 104   }
 105 
 106   NOT_PRODUCT(set_compiled_invocation_count(0);)
 107 }
 108 
 109 // Release Method*.  The nmethod will be gone when we get here because
 110 // we've walked the code cache.
 111 void Method::deallocate_contents(ClassLoaderData* loader_data) {
 112   MetadataFactory::free_metadata(loader_data, constMethod());
 113   set_constMethod(NULL);
 114   MetadataFactory::free_metadata(loader_data, method_data());
 115   set_method_data(NULL);
 116   MetadataFactory::free_metadata(loader_data, method_counters());
 117   clear_method_counters();
 118   // The nmethod will be gone when we get here.
 119   if (code() != NULL) _code = NULL;
 120 }
 121 
 122 address Method::get_i2c_entry() {
 123   assert(_adapter != NULL, "must have");
 124   return _adapter->get_i2c_entry();
 125 }
 126 
 127 address Method::get_c2i_entry() {
 128   assert(_adapter != NULL, "must have");
 129   return _adapter->get_c2i_entry();
 130 }
 131 
 132 address Method::get_c2i_unverified_entry() {
 133   assert(_adapter != NULL, "must have");
 134   return _adapter->get_c2i_unverified_entry();
 135 }
 136 
 137 char* Method::name_and_sig_as_C_string() const {
 138   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
 139 }
 140 
 141 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
 142   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
 143 }
 144 
 145 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
 146   const char* klass_name = klass->external_name();
 147   int klass_name_len  = (int)strlen(klass_name);
 148   int method_name_len = method_name->utf8_length();
 149   int len             = klass_name_len + 1 + method_name_len + signature->utf8_length();
 150   char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);
 151   strcpy(dest, klass_name);
 152   dest[klass_name_len] = '.';
 153   strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
 154   strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
 155   dest[len] = 0;
 156   return dest;
 157 }
 158 
 159 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
 160   Symbol* klass_name = klass->name();
 161   klass_name->as_klass_external_name(buf, size);
 162   int len = (int)strlen(buf);
 163 
 164   if (len < size - 1) {
 165     buf[len++] = '.';
 166 
 167     method_name->as_C_string(&(buf[len]), size - len);
 168     len = (int)strlen(buf);
 169 
 170     signature->as_C_string(&(buf[len]), size - len);
 171   }
 172 
 173   return buf;
 174 }
 175 
 176 int Method::fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS) {
 177   // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
 178   // access exception table
 179   ExceptionTable table(mh());
 180   int length = table.length();
 181   // iterate through all entries sequentially
 182   constantPoolHandle pool(THREAD, mh->constants());
 183   for (int i = 0; i < length; i ++) {
 184     //reacquire the table in case a GC happened
 185     ExceptionTable table(mh());
 186     int beg_bci = table.start_pc(i);
 187     int end_bci = table.end_pc(i);
 188     assert(beg_bci <= end_bci, "inconsistent exception table");
 189     if (beg_bci <= throw_bci && throw_bci < end_bci) {
 190       // exception handler bci range covers throw_bci => investigate further
 191       int handler_bci = table.handler_pc(i);
 192       int klass_index = table.catch_type_index(i);
 193       if (klass_index == 0) {
 194         return handler_bci;
 195       } else if (ex_klass.is_null()) {
 196         return handler_bci;
 197       } else {
 198         // we know the exception class => get the constraint class
 199         // this may require loading of the constraint class; if verification
 200         // fails or some other exception occurs, return handler_bci
 201         Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
 202         KlassHandle klass = KlassHandle(THREAD, k);
 203         assert(klass.not_null(), "klass not loaded");
 204         if (ex_klass->is_subtype_of(klass())) {
 205           return handler_bci;
 206         }
 207       }
 208     }
 209   }
 210 
 211   return -1;
 212 }
 213 
 214 void Method::mask_for(int bci, InterpreterOopMap* mask) {
 215 
 216   Thread* myThread    = Thread::current();
 217   methodHandle h_this(myThread, this);
 218 #if defined(ASSERT) && !INCLUDE_JVMCI
 219   bool has_capability = myThread->is_VM_thread() ||
 220                         myThread->is_ConcurrentGC_thread() ||
 221                         myThread->is_GC_task_thread();
 222 
 223   if (!has_capability) {
 224     if (!VerifyStack && !VerifyLastFrame) {
 225       // verify stack calls this outside VM thread
 226       warning("oopmap should only be accessed by the "
 227               "VM, GC task or CMS threads (or during debugging)");
 228       InterpreterOopMap local_mask;
 229       method_holder()->mask_for(h_this, bci, &local_mask);
 230       local_mask.print();
 231     }
 232   }
 233 #endif
 234   method_holder()->mask_for(h_this, bci, mask);
 235   return;
 236 }
 237 
 238 
 239 int Method::bci_from(address bcp) const {
 240   if (is_native() && bcp == 0) {
 241     return 0;
 242   }
 243 #ifdef ASSERT
 244   {
 245     ResourceMark rm;
 246     assert(is_native() && bcp == code_base() || contains(bcp) || is_error_reported(),
 247            "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
 248            p2i(bcp), name_and_sig_as_C_string());
 249   }
 250 #endif
 251   return bcp - code_base();
 252 }
 253 
 254 
 255 int Method::validate_bci(int bci) const {
 256   return (bci == 0 || bci < code_size()) ? bci : -1;
 257 }
 258 
 259 // Return bci if it appears to be a valid bcp
 260 // Return -1 otherwise.
 261 // Used by profiling code, when invalid data is a possibility.
 262 // The caller is responsible for validating the Method* itself.
 263 int Method::validate_bci_from_bcp(address bcp) const {
 264   // keep bci as -1 if not a valid bci
 265   int bci = -1;
 266   if (bcp == 0 || bcp == code_base()) {
 267     // code_size() may return 0 and we allow 0 here
 268     // the method may be native
 269     bci = 0;
 270   } else if (contains(bcp)) {
 271     bci = bcp - code_base();
 272   }
 273   // Assert that if we have dodged any asserts, bci is negative.
 274   assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
 275   return bci;
 276 }
 277 
 278 address Method::bcp_from(int bci) const {
 279   assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()), "illegal bci: %d", bci);
 280   address bcp = code_base() + bci;
 281   assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
 282   return bcp;
 283 }
 284 
 285 address Method::bcp_from(address bcp) const {
 286   if (is_native() && bcp == NULL) {
 287     return code_base();
 288   } else {
 289     return bcp;
 290   }
 291 }
 292 
 293 int Method::size(bool is_native) {
 294   // If native, then include pointers for native_function and signature_handler
 295   int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
 296   int extra_words = align_size_up(extra_bytes, BytesPerWord) / BytesPerWord;
 297   return align_object_size(header_size() + extra_words);
 298 }
 299 
 300 
 301 Symbol* Method::klass_name() const {
 302   Klass* k = method_holder();
 303   assert(k->is_klass(), "must be klass");
 304   InstanceKlass* ik = (InstanceKlass*) k;
 305   return ik->name();
 306 }
 307 
 308 
 309 // Attempt to return method oop to original state.  Clear any pointers
 310 // (to objects outside the shared spaces).  We won't be able to predict
 311 // where they should point in a new JVM.  Further initialize some
 312 // entries now in order allow them to be write protected later.
 313 
 314 void Method::remove_unshareable_info() {
 315   unlink_method();
 316 }
 317 
 318 
 319 bool Method::was_executed_more_than(int n) {
 320   // Invocation counter is reset when the Method* is compiled.
 321   // If the method has compiled code we therefore assume it has
 322   // be excuted more than n times.
 323   if (is_accessor() || is_empty_method() || (code() != NULL)) {
 324     // interpreter doesn't bump invocation counter of trivial methods
 325     // compiler does not bump invocation counter of compiled methods
 326     return true;
 327   }
 328   else if ((method_counters() != NULL &&
 329             method_counters()->invocation_counter()->carry()) ||
 330            (method_data() != NULL &&
 331             method_data()->invocation_counter()->carry())) {
 332     // The carry bit is set when the counter overflows and causes
 333     // a compilation to occur.  We don't know how many times
 334     // the counter has been reset, so we simply assume it has
 335     // been executed more than n times.
 336     return true;
 337   } else {
 338     return invocation_count() > n;
 339   }
 340 }
 341 
 342 void Method::print_invocation_count() {
 343   if (is_static()) tty->print("static ");
 344   if (is_final()) tty->print("final ");
 345   if (is_synchronized()) tty->print("synchronized ");
 346   if (is_native()) tty->print("native ");
 347   tty->print("%s::", method_holder()->external_name());
 348   name()->print_symbol_on(tty);
 349   signature()->print_symbol_on(tty);
 350 
 351   if (WizardMode) {
 352     // dump the size of the byte codes
 353     tty->print(" {%d}", code_size());
 354   }
 355   tty->cr();
 356 
 357   tty->print_cr ("  interpreter_invocation_count: %8d ", interpreter_invocation_count());
 358   tty->print_cr ("  invocation_counter:           %8d ", invocation_count());
 359   tty->print_cr ("  backedge_counter:             %8d ", backedge_count());
 360 #ifndef PRODUCT
 361   if (CountCompiledCalls) {
 362     tty->print_cr ("  compiled_invocation_count: %8d ", compiled_invocation_count());
 363   }
 364 #endif
 365 }
 366 
 367 // Build a MethodData* object to hold information about this method
 368 // collected in the interpreter.
 369 void Method::build_interpreter_method_data(methodHandle method, TRAPS) {
 370   // Do not profile the method if metaspace has hit an OOM previously
 371   // allocating profiling data. Callers clear pending exception so don't
 372   // add one here.
 373   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 374     return;
 375   }
 376 
 377   // Do not profile method if current thread holds the pending list lock,
 378   // which avoids deadlock for acquiring the MethodData_lock.
 379   if (InstanceRefKlass::owns_pending_list_lock((JavaThread*)THREAD)) {
 380     return;
 381   }
 382 
 383   // Grab a lock here to prevent multiple
 384   // MethodData*s from being created.
 385   MutexLocker ml(MethodData_lock, THREAD);
 386   if (method->method_data() == NULL) {
 387     ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
 388     MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
 389     if (HAS_PENDING_EXCEPTION) {
 390       CompileBroker::log_metaspace_failure();
 391       ClassLoaderDataGraph::set_metaspace_oom(true);
 392       return;   // return the exception (which is cleared)
 393     }
 394 
 395     method->set_method_data(method_data);
 396     if (PrintMethodData && (Verbose || WizardMode)) {
 397       ResourceMark rm(THREAD);
 398       tty->print("build_interpreter_method_data for ");
 399       method->print_name(tty);
 400       tty->cr();
 401       // At the end of the run, the MDO, full of data, will be dumped.
 402     }
 403   }
 404 }
 405 
 406 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
 407   // Do not profile the method if metaspace has hit an OOM previously
 408   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 409     return NULL;
 410   }
 411 
 412   methodHandle mh(m);
 413   MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
 414   if (HAS_PENDING_EXCEPTION) {
 415     CompileBroker::log_metaspace_failure();
 416     ClassLoaderDataGraph::set_metaspace_oom(true);
 417     return NULL;   // return the exception (which is cleared)
 418   }
 419   if (!mh->init_method_counters(counters)) {
 420     MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
 421   }
 422 
 423   if (LogTouchedMethods) {
 424     mh->log_touched(CHECK_NULL);
 425   }
 426 
 427   return mh->method_counters();
 428 }
 429 
 430 void Method::cleanup_inline_caches() {
 431   // The current system doesn't use inline caches in the interpreter
 432   // => nothing to do (keep this method around for future use)
 433 }
 434 
 435 
 436 int Method::extra_stack_words() {
 437   // not an inline function, to avoid a header dependency on Interpreter
 438   return extra_stack_entries() * Interpreter::stackElementSize;
 439 }
 440 
 441 
 442 void Method::compute_size_of_parameters(Thread *thread) {
 443   ArgumentSizeComputer asc(signature());
 444   set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
 445 }
 446 
 447 #ifdef CC_INTERP
 448 void Method::set_result_index(BasicType type)          {
 449   _result_index = Interpreter::BasicType_as_index(type);
 450 }
 451 #endif
 452 
 453 BasicType Method::result_type() const {
 454   ResultTypeFinder rtf(signature());
 455   return rtf.type();
 456 }
 457 
 458 
 459 bool Method::is_empty_method() const {
 460   return  code_size() == 1
 461       && *code_base() == Bytecodes::_return;
 462 }
 463 
 464 
 465 bool Method::is_vanilla_constructor() const {
 466   // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
 467   // which only calls the superclass vanilla constructor and possibly does stores of
 468   // zero constants to local fields:
 469   //
 470   //   aload_0
 471   //   invokespecial
 472   //   indexbyte1
 473   //   indexbyte2
 474   //
 475   // followed by an (optional) sequence of:
 476   //
 477   //   aload_0
 478   //   aconst_null / iconst_0 / fconst_0 / dconst_0
 479   //   putfield
 480   //   indexbyte1
 481   //   indexbyte2
 482   //
 483   // followed by:
 484   //
 485   //   return
 486 
 487   assert(name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructors");
 488   assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
 489   int size = code_size();
 490   // Check if size match
 491   if (size == 0 || size % 5 != 0) return false;
 492   address cb = code_base();
 493   int last = size - 1;
 494   if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
 495     // Does not call superclass default constructor
 496     return false;
 497   }
 498   // Check optional sequence
 499   for (int i = 4; i < last; i += 5) {
 500     if (cb[i] != Bytecodes::_aload_0) return false;
 501     if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
 502     if (cb[i+2] != Bytecodes::_putfield) return false;
 503   }
 504   return true;
 505 }
 506 
 507 
 508 bool Method::compute_has_loops_flag() {
 509   BytecodeStream bcs(this);
 510   Bytecodes::Code bc;
 511 
 512   while ((bc = bcs.next()) >= 0) {
 513     switch( bc ) {
 514       case Bytecodes::_ifeq:
 515       case Bytecodes::_ifnull:
 516       case Bytecodes::_iflt:
 517       case Bytecodes::_ifle:
 518       case Bytecodes::_ifne:
 519       case Bytecodes::_ifnonnull:
 520       case Bytecodes::_ifgt:
 521       case Bytecodes::_ifge:
 522       case Bytecodes::_if_icmpeq:
 523       case Bytecodes::_if_icmpne:
 524       case Bytecodes::_if_icmplt:
 525       case Bytecodes::_if_icmpgt:
 526       case Bytecodes::_if_icmple:
 527       case Bytecodes::_if_icmpge:
 528       case Bytecodes::_if_acmpeq:
 529       case Bytecodes::_if_acmpne:
 530       case Bytecodes::_goto:
 531       case Bytecodes::_jsr:
 532         if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
 533         break;
 534 
 535       case Bytecodes::_goto_w:
 536       case Bytecodes::_jsr_w:
 537         if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
 538         break;
 539     }
 540   }
 541   _access_flags.set_loops_flag_init();
 542   return _access_flags.has_loops();
 543 }
 544 
 545 bool Method::is_final_method(AccessFlags class_access_flags) const {
 546   // or "does_not_require_vtable_entry"
 547   // default method or overpass can occur, is not final (reuses vtable entry)
 548   // private methods get vtable entries for backward class compatibility.
 549   if (is_overpass() || is_default_method())  return false;
 550   return is_final() || class_access_flags.is_final();
 551 }
 552 
 553 bool Method::is_final_method() const {
 554   return is_final_method(method_holder()->access_flags());
 555 }
 556 
 557 bool Method::is_default_method() const {
 558   if (method_holder() != NULL &&
 559       method_holder()->is_interface() &&
 560       !is_abstract()) {
 561     return true;
 562   } else {
 563     return false;
 564   }
 565 }
 566 
 567 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
 568   if (is_final_method(class_access_flags))  return true;
 569 #ifdef ASSERT
 570   ResourceMark rm;
 571   bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
 572   if (class_access_flags.is_interface()) {
 573     assert(is_nonv == is_static(), "is_nonv=%s", name_and_sig_as_C_string());
 574   }
 575 #endif
 576   assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
 577   return vtable_index() == nonvirtual_vtable_index;
 578 }
 579 
 580 bool Method::can_be_statically_bound() const {
 581   return can_be_statically_bound(method_holder()->access_flags());
 582 }
 583 
 584 bool Method::is_accessor() const {
 585   if (code_size() != 5) return false;
 586   if (size_of_parameters() != 1) return false;
 587   if (java_code_at(0) != Bytecodes::_aload_0 ) return false;
 588   if (java_code_at(1) != Bytecodes::_getfield) return false;
 589   if (java_code_at(4) != Bytecodes::_areturn &&
 590       java_code_at(4) != Bytecodes::_ireturn ) return false;
 591   return true;
 592 }
 593 
 594 bool Method::is_constant_getter() const {
 595   int last_index = code_size() - 1;
 596   // Check if the first 1-3 bytecodes are a constant push
 597   // and the last bytecode is a return.
 598   return (2 <= code_size() && code_size() <= 4 &&
 599           Bytecodes::is_const(java_code_at(0)) &&
 600           Bytecodes::length_for(java_code_at(0)) == last_index &&
 601           Bytecodes::is_return(java_code_at(last_index)));
 602 }
 603 
 604 bool Method::is_initializer() const {
 605   return name() == vmSymbols::object_initializer_name() || is_static_initializer();
 606 }
 607 
 608 bool Method::has_valid_initializer_flags() const {
 609   return (is_static() ||
 610           method_holder()->major_version() < 51);
 611 }
 612 
 613 bool Method::is_static_initializer() const {
 614   // For classfiles version 51 or greater, ensure that the clinit method is
 615   // static.  Non-static methods with the name "<clinit>" are not static
 616   // initializers. (older classfiles exempted for backward compatibility)
 617   return name() == vmSymbols::class_initializer_name() &&
 618          has_valid_initializer_flags();
 619 }
 620 
 621 
 622 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
 623   int length = method->checked_exceptions_length();
 624   if (length == 0) {  // common case
 625     return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
 626   } else {
 627     methodHandle h_this(THREAD, method);
 628     objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
 629     objArrayHandle mirrors (THREAD, m_oop);
 630     for (int i = 0; i < length; i++) {
 631       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
 632       Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
 633       assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
 634       mirrors->obj_at_put(i, k->java_mirror());
 635     }
 636     return mirrors;
 637   }
 638 };
 639 
 640 
 641 int Method::line_number_from_bci(int bci) const {
 642   if (bci == SynchronizationEntryBCI) bci = 0;
 643   assert(bci == 0 || 0 <= bci && bci < code_size(), "illegal bci");
 644   int best_bci  =  0;
 645   int best_line = -1;
 646 
 647   if (has_linenumber_table()) {
 648     // The line numbers are a short array of 2-tuples [start_pc, line_number].
 649     // Not necessarily sorted and not necessarily one-to-one.
 650     CompressedLineNumberReadStream stream(compressed_linenumber_table());
 651     while (stream.read_pair()) {
 652       if (stream.bci() == bci) {
 653         // perfect match
 654         return stream.line();
 655       } else {
 656         // update best_bci/line
 657         if (stream.bci() < bci && stream.bci() >= best_bci) {
 658           best_bci  = stream.bci();
 659           best_line = stream.line();
 660         }
 661       }
 662     }
 663   }
 664   return best_line;
 665 }
 666 
 667 
 668 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
 669   if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
 670     Thread *thread = Thread::current();
 671     Symbol* klass_name = constants()->klass_name_at(klass_index);
 672     Handle loader(thread, method_holder()->class_loader());
 673     Handle prot  (thread, method_holder()->protection_domain());
 674     return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
 675   } else {
 676     return true;
 677   }
 678 }
 679 
 680 
 681 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
 682   int klass_index = constants()->klass_ref_index_at(refinfo_index);
 683   if (must_be_resolved) {
 684     // Make sure klass is resolved in constantpool.
 685     if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
 686   }
 687   return is_klass_loaded_by_klass_index(klass_index);
 688 }
 689 
 690 
 691 void Method::set_native_function(address function, bool post_event_flag) {
 692   assert(function != NULL, "use clear_native_function to unregister natives");
 693   assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
 694   address* native_function = native_function_addr();
 695 
 696   // We can see racers trying to place the same native function into place. Once
 697   // is plenty.
 698   address current = *native_function;
 699   if (current == function) return;
 700   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
 701       function != NULL) {
 702     // native_method_throw_unsatisfied_link_error_entry() should only
 703     // be passed when post_event_flag is false.
 704     assert(function !=
 705       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 706       "post_event_flag mis-match");
 707 
 708     // post the bind event, and possible change the bind function
 709     JvmtiExport::post_native_method_bind(this, &function);
 710   }
 711   *native_function = function;
 712   // This function can be called more than once. We must make sure that we always
 713   // use the latest registered method -> check if a stub already has been generated.
 714   // If so, we have to make it not_entrant.
 715   nmethod* nm = code(); // Put it into local variable to guard against concurrent updates
 716   if (nm != NULL) {
 717     nm->make_not_entrant();
 718   }
 719 }
 720 
 721 
 722 bool Method::has_native_function() const {
 723   if (is_method_handle_intrinsic())
 724     return false;  // special-cased in SharedRuntime::generate_native_wrapper
 725   address func = native_function();
 726   return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
 727 }
 728 
 729 
 730 void Method::clear_native_function() {
 731   // Note: is_method_handle_intrinsic() is allowed here.
 732   set_native_function(
 733     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 734     !native_bind_event_is_interesting);
 735   clear_code();
 736 }
 737 
 738 address Method::critical_native_function() {
 739   methodHandle mh(this);
 740   return NativeLookup::lookup_critical_entry(mh);
 741 }
 742 
 743 
 744 void Method::set_signature_handler(address handler) {
 745   address* signature_handler =  signature_handler_addr();
 746   *signature_handler = handler;
 747 }
 748 
 749 
 750 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
 751   if (PrintCompilation && report) {
 752     ttyLocker ttyl;
 753     tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
 754     if (comp_level == CompLevel_all) {
 755       tty->print("all levels ");
 756     } else {
 757       tty->print("levels ");
 758       for (int i = (int)CompLevel_none; i <= comp_level; i++) {
 759         tty->print("%d ", i);
 760       }
 761     }
 762     this->print_short_name(tty);
 763     int size = this->code_size();
 764     if (size > 0) {
 765       tty->print(" (%d bytes)", size);
 766     }
 767     if (reason != NULL) {
 768       tty->print("   %s", reason);
 769     }
 770     tty->cr();
 771   }
 772   if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
 773     ttyLocker ttyl;
 774     xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
 775                      os::current_thread_id(), is_osr, comp_level);
 776     if (reason != NULL) {
 777       xtty->print(" reason=\'%s\'", reason);
 778     }
 779     xtty->method(this);
 780     xtty->stamp();
 781     xtty->end_elem();
 782   }
 783 }
 784 
 785 bool Method::is_always_compilable() const {
 786   // Generated adapters must be compiled
 787   if (is_method_handle_intrinsic() && is_synthetic()) {
 788     assert(!is_not_c1_compilable(), "sanity check");
 789     assert(!is_not_c2_compilable(), "sanity check");
 790     return true;
 791   }
 792 
 793   return false;
 794 }
 795 
 796 bool Method::is_not_compilable(int comp_level) const {
 797   if (number_of_breakpoints() > 0)
 798     return true;
 799   if (is_always_compilable())
 800     return false;
 801   if (comp_level == CompLevel_any)
 802     return is_not_c1_compilable() || is_not_c2_compilable();
 803   if (is_c1_compile(comp_level))
 804     return is_not_c1_compilable();
 805   if (is_c2_compile(comp_level))
 806     return is_not_c2_compilable();
 807   return false;
 808 }
 809 
 810 // call this when compiler finds that this method is not compilable
 811 void Method::set_not_compilable(int comp_level, bool report, const char* reason) {
 812   if (is_always_compilable()) {
 813     // Don't mark a method which should be always compilable
 814     return;
 815   }
 816   print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
 817   if (comp_level == CompLevel_all) {
 818     set_not_c1_compilable();
 819     set_not_c2_compilable();
 820   } else {
 821     if (is_c1_compile(comp_level))
 822       set_not_c1_compilable();
 823     if (is_c2_compile(comp_level))
 824       set_not_c2_compilable();
 825   }
 826   CompilationPolicy::policy()->disable_compilation(this);
 827   assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
 828 }
 829 
 830 bool Method::is_not_osr_compilable(int comp_level) const {
 831   if (is_not_compilable(comp_level))
 832     return true;
 833   if (comp_level == CompLevel_any)
 834     return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
 835   if (is_c1_compile(comp_level))
 836     return is_not_c1_osr_compilable();
 837   if (is_c2_compile(comp_level))
 838     return is_not_c2_osr_compilable();
 839   return false;
 840 }
 841 
 842 void Method::set_not_osr_compilable(int comp_level, bool report, const char* reason) {
 843   print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
 844   if (comp_level == CompLevel_all) {
 845     set_not_c1_osr_compilable();
 846     set_not_c2_osr_compilable();
 847   } else {
 848     if (is_c1_compile(comp_level))
 849       set_not_c1_osr_compilable();
 850     if (is_c2_compile(comp_level))
 851       set_not_c2_osr_compilable();
 852   }
 853   CompilationPolicy::policy()->disable_compilation(this);
 854   assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
 855 }
 856 
 857 // Revert to using the interpreter and clear out the nmethod
 858 void Method::clear_code() {
 859 
 860   // this may be NULL if c2i adapters have not been made yet
 861   // Only should happen at allocate time.
 862   if (_adapter == NULL) {
 863     _from_compiled_entry    = NULL;
 864   } else {
 865     _from_compiled_entry    = _adapter->get_c2i_entry();
 866   }
 867   OrderAccess::storestore();
 868   _from_interpreted_entry = _i2i_entry;
 869   OrderAccess::storestore();
 870   _code = NULL;
 871 }
 872 
 873 // Called by class data sharing to remove any entry points (which are not shared)
 874 void Method::unlink_method() {
 875   _code = NULL;
 876   _i2i_entry = NULL;
 877   _from_interpreted_entry = NULL;
 878   if (is_native()) {
 879     *native_function_addr() = NULL;
 880     set_signature_handler(NULL);
 881   }
 882   NOT_PRODUCT(set_compiled_invocation_count(0);)
 883   _adapter = NULL;
 884   _from_compiled_entry = NULL;
 885 
 886   // In case of DumpSharedSpaces, _method_data should always be NULL.
 887   //
 888   // During runtime (!DumpSharedSpaces), when we are cleaning a
 889   // shared class that failed to load, this->link_method() may
 890   // have already been called (before an exception happened), so
 891   // this->_method_data may not be NULL.
 892   assert(!DumpSharedSpaces || _method_data == NULL, "unexpected method data?");
 893 
 894   set_method_data(NULL);
 895   clear_method_counters();
 896 }
 897 
 898 // Called when the method_holder is getting linked. Setup entrypoints so the method
 899 // is ready to be called from interpreter, compiler, and vtables.
 900 void Method::link_method(methodHandle h_method, TRAPS) {
 901   // If the code cache is full, we may reenter this function for the
 902   // leftover methods that weren't linked.
 903   if (_i2i_entry != NULL) return;
 904 
 905   assert(_adapter == NULL, "init'd to NULL" );
 906   assert( _code == NULL, "nothing compiled yet" );
 907 
 908   // Setup interpreter entrypoint
 909   assert(this == h_method(), "wrong h_method()" );
 910   address entry = Interpreter::entry_for_method(h_method);
 911   assert(entry != NULL, "interpreter entry must be non-null");
 912   // Sets both _i2i_entry and _from_interpreted_entry
 913   set_interpreter_entry(entry);
 914 
 915   // Don't overwrite already registered native entries.
 916   if (is_native() && !has_native_function()) {
 917     set_native_function(
 918       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 919       !native_bind_event_is_interesting);
 920   }
 921 
 922   // Setup compiler entrypoint.  This is made eagerly, so we do not need
 923   // special handling of vtables.  An alternative is to make adapters more
 924   // lazily by calling make_adapter() from from_compiled_entry() for the
 925   // normal calls.  For vtable calls life gets more complicated.  When a
 926   // call-site goes mega-morphic we need adapters in all methods which can be
 927   // called from the vtable.  We need adapters on such methods that get loaded
 928   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
 929   // problem we'll make these lazily later.
 930   (void) make_adapters(h_method, CHECK);
 931 
 932   // ONLY USE the h_method now as make_adapter may have blocked
 933 
 934 }
 935 
 936 address Method::make_adapters(methodHandle mh, TRAPS) {
 937   // Adapters for compiled code are made eagerly here.  They are fairly
 938   // small (generally < 100 bytes) and quick to make (and cached and shared)
 939   // so making them eagerly shouldn't be too expensive.
 940   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
 941   if (adapter == NULL ) {
 942     THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
 943   }
 944 
 945   mh->set_adapter_entry(adapter);
 946   mh->_from_compiled_entry = adapter->get_c2i_entry();
 947   return adapter->get_c2i_entry();
 948 }
 949 
 950 void Method::restore_unshareable_info(TRAPS) {
 951   // Since restore_unshareable_info can be called more than once for a method, don't
 952   // redo any work.   If this field is restored, there is nothing to do.
 953   if (_from_compiled_entry == NULL) {
 954     // restore method's vtable by calling a virtual function
 955     restore_vtable();
 956 
 957     methodHandle mh(THREAD, this);
 958     link_method(mh, CHECK);
 959   }
 960 }
 961 
 962 
 963 // The verified_code_entry() must be called when a invoke is resolved
 964 // on this method.
 965 
 966 // It returns the compiled code entry point, after asserting not null.
 967 // This function is called after potential safepoints so that nmethod
 968 // or adapter that it points to is still live and valid.
 969 // This function must not hit a safepoint!
 970 address Method::verified_code_entry() {
 971   debug_only(No_Safepoint_Verifier nsv;)
 972   assert(_from_compiled_entry != NULL, "must be set");
 973   return _from_compiled_entry;
 974 }
 975 
 976 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
 977 // (could be racing a deopt).
 978 // Not inline to avoid circular ref.
 979 bool Method::check_code() const {
 980   // cached in a register or local.  There's a race on the value of the field.
 981   nmethod *code = (nmethod *)OrderAccess::load_ptr_acquire(&_code);
 982   return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
 983 }
 984 
 985 // Install compiled code.  Instantly it can execute.
 986 void Method::set_code(methodHandle mh, nmethod *code) {
 987   assert( code, "use clear_code to remove code" );
 988   assert( mh->check_code(), "" );
 989 
 990   guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
 991 
 992   // These writes must happen in this order, because the interpreter will
 993   // directly jump to from_interpreted_entry which jumps to an i2c adapter
 994   // which jumps to _from_compiled_entry.
 995   mh->_code = code;             // Assign before allowing compiled code to exec
 996 
 997   int comp_level = code->comp_level();
 998   // In theory there could be a race here. In practice it is unlikely
 999   // and not worth worrying about.
1000   if (comp_level > mh->highest_comp_level()) {
1001     mh->set_highest_comp_level(comp_level);
1002   }
1003 
1004   OrderAccess::storestore();
1005 #ifdef SHARK
1006   mh->_from_interpreted_entry = code->insts_begin();
1007 #else //!SHARK
1008   mh->_from_compiled_entry = code->verified_entry_point();
1009   OrderAccess::storestore();
1010   // Instantly compiled code can execute.
1011   if (!mh->is_method_handle_intrinsic())
1012     mh->_from_interpreted_entry = mh->get_i2c_entry();
1013 #endif //!SHARK
1014 }
1015 
1016 
1017 bool Method::is_overridden_in(Klass* k) const {
1018   InstanceKlass* ik = InstanceKlass::cast(k);
1019 
1020   if (ik->is_interface()) return false;
1021 
1022   // If method is an interface, we skip it - except if it
1023   // is a miranda method
1024   if (method_holder()->is_interface()) {
1025     // Check that method is not a miranda method
1026     if (ik->lookup_method(name(), signature()) == NULL) {
1027       // No implementation exist - so miranda method
1028       return false;
1029     }
1030     return true;
1031   }
1032 
1033   assert(ik->is_subclass_of(method_holder()), "should be subklass");
1034   assert(ik->vtable() != NULL, "vtable should exist");
1035   if (!has_vtable_index()) {
1036     return false;
1037   } else {
1038     Method* vt_m = ik->method_at_vtable(vtable_index());
1039     return vt_m != this;
1040   }
1041 }
1042 
1043 
1044 // give advice about whether this Method* should be cached or not
1045 bool Method::should_not_be_cached() const {
1046   if (is_old()) {
1047     // This method has been redefined. It is either EMCP or obsolete
1048     // and we don't want to cache it because that would pin the method
1049     // down and prevent it from being collectible if and when it
1050     // finishes executing.
1051     return true;
1052   }
1053 
1054   // caching this method should be just fine
1055   return false;
1056 }
1057 
1058 
1059 /**
1060  *  Returns true if this is one of the specially treated methods for
1061  *  security related stack walks (like Reflection.getCallerClass).
1062  */
1063 bool Method::is_ignored_by_security_stack_walk() const {
1064   if (intrinsic_id() == vmIntrinsics::_invoke) {
1065     // This is Method.invoke() -- ignore it
1066     return true;
1067   }
1068   if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1069     // This is an auxilary frame -- ignore it
1070     return true;
1071   }
1072   if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1073     // This is an internal adapter frame for method handles -- ignore it
1074     return true;
1075   }
1076   return false;
1077 }
1078 
1079 
1080 // Constant pool structure for invoke methods:
1081 enum {
1082   _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.
1083   _imcp_invoke_signature,       // utf8: (variable Symbol*)
1084   _imcp_limit
1085 };
1086 
1087 // Test if this method is an MH adapter frame generated by Java code.
1088 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1089 bool Method::is_compiled_lambda_form() const {
1090   return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1091 }
1092 
1093 // Test if this method is an internal MH primitive method.
1094 bool Method::is_method_handle_intrinsic() const {
1095   vmIntrinsics::ID iid = intrinsic_id();
1096   return (MethodHandles::is_signature_polymorphic(iid) &&
1097           MethodHandles::is_signature_polymorphic_intrinsic(iid));
1098 }
1099 
1100 bool Method::has_member_arg() const {
1101   vmIntrinsics::ID iid = intrinsic_id();
1102   return (MethodHandles::is_signature_polymorphic(iid) &&
1103           MethodHandles::has_member_arg(iid));
1104 }
1105 
1106 // Make an instance of a signature-polymorphic internal MH primitive.
1107 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1108                                                          Symbol* signature,
1109                                                          TRAPS) {
1110   ResourceMark rm;
1111   methodHandle empty;
1112 
1113   KlassHandle holder = SystemDictionary::MethodHandle_klass();
1114   Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1115   assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1116   if (TraceMethodHandles) {
1117     tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1118   }
1119 
1120   // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1121   name->increment_refcount();
1122   signature->increment_refcount();
1123 
1124   int cp_length = _imcp_limit;
1125   ClassLoaderData* loader_data = holder->class_loader_data();
1126   constantPoolHandle cp;
1127   {
1128     ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1129     cp = constantPoolHandle(THREAD, cp_oop);
1130   }
1131   cp->set_pool_holder(InstanceKlass::cast(holder()));
1132   cp->symbol_at_put(_imcp_invoke_name,       name);
1133   cp->symbol_at_put(_imcp_invoke_signature,  signature);
1134   cp->set_has_preresolution();
1135 
1136   // decide on access bits:  public or not?
1137   int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1138   bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1139   if (must_be_static)  flags_bits |= JVM_ACC_STATIC;
1140   assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1141 
1142   methodHandle m;
1143   {
1144     InlineTableSizes sizes;
1145     Method* m_oop = Method::allocate(loader_data, 0,
1146                                      accessFlags_from(flags_bits), &sizes,
1147                                      ConstMethod::NORMAL, CHECK_(empty));
1148     m = methodHandle(THREAD, m_oop);
1149   }
1150   m->set_constants(cp());
1151   m->set_name_index(_imcp_invoke_name);
1152   m->set_signature_index(_imcp_invoke_signature);
1153   assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1154   assert(m->signature() == signature, "");
1155 #ifdef CC_INTERP
1156   ResultTypeFinder rtf(signature);
1157   m->set_result_index(rtf.type());
1158 #endif
1159   m->compute_size_of_parameters(THREAD);
1160   m->init_intrinsic_id();
1161   assert(m->is_method_handle_intrinsic(), "");
1162 #ifdef ASSERT
1163   if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();
1164   assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1165   assert(m->intrinsic_id() == iid, "correctly predicted iid");
1166 #endif //ASSERT
1167 
1168   // Finally, set up its entry points.
1169   assert(m->can_be_statically_bound(), "");
1170   m->set_vtable_index(Method::nonvirtual_vtable_index);
1171   m->link_method(m, CHECK_(empty));
1172 
1173   if (TraceMethodHandles && (Verbose || WizardMode))
1174     m->print_on(tty);
1175 
1176   return m;
1177 }
1178 
1179 Klass* Method::check_non_bcp_klass(Klass* klass) {
1180   if (klass != NULL && klass->class_loader() != NULL) {
1181     if (klass->oop_is_objArray())
1182       klass = ObjArrayKlass::cast(klass)->bottom_klass();
1183     return klass;
1184   }
1185   return NULL;
1186 }
1187 
1188 
1189 methodHandle Method::clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
1190                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1191   // Code below does not work for native methods - they should never get rewritten anyway
1192   assert(!m->is_native(), "cannot rewrite native methods");
1193   // Allocate new Method*
1194   AccessFlags flags = m->access_flags();
1195 
1196   ConstMethod* cm = m->constMethod();
1197   int checked_exceptions_len = cm->checked_exceptions_length();
1198   int localvariable_len = cm->localvariable_table_length();
1199   int exception_table_len = cm->exception_table_length();
1200   int method_parameters_len = cm->method_parameters_length();
1201   int method_annotations_len = cm->method_annotations_length();
1202   int parameter_annotations_len = cm->parameter_annotations_length();
1203   int type_annotations_len = cm->type_annotations_length();
1204   int default_annotations_len = cm->default_annotations_length();
1205 
1206   InlineTableSizes sizes(
1207       localvariable_len,
1208       new_compressed_linenumber_size,
1209       exception_table_len,
1210       checked_exceptions_len,
1211       method_parameters_len,
1212       cm->generic_signature_index(),
1213       method_annotations_len,
1214       parameter_annotations_len,
1215       type_annotations_len,
1216       default_annotations_len,
1217       0);
1218 
1219   ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1220   Method* newm_oop = Method::allocate(loader_data,
1221                                       new_code_length,
1222                                       flags,
1223                                       &sizes,
1224                                       m->method_type(),
1225                                       CHECK_(methodHandle()));
1226   methodHandle newm (THREAD, newm_oop);
1227 
1228   // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1229   ConstMethod* newcm = newm->constMethod();
1230   int new_const_method_size = newm->constMethod()->size();
1231 
1232   memcpy(newm(), m(), sizeof(Method));
1233 
1234   // Create shallow copy of ConstMethod.
1235   memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1236 
1237   // Reset correct method/const method, method size, and parameter info
1238   newm->set_constMethod(newcm);
1239   newm->constMethod()->set_code_size(new_code_length);
1240   newm->constMethod()->set_constMethod_size(new_const_method_size);
1241   assert(newm->code_size() == new_code_length, "check");
1242   assert(newm->method_parameters_length() == method_parameters_len, "check");
1243   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1244   assert(newm->exception_table_length() == exception_table_len, "check");
1245   assert(newm->localvariable_table_length() == localvariable_len, "check");
1246   // Copy new byte codes
1247   memcpy(newm->code_base(), new_code, new_code_length);
1248   // Copy line number table
1249   if (new_compressed_linenumber_size > 0) {
1250     memcpy(newm->compressed_linenumber_table(),
1251            new_compressed_linenumber_table,
1252            new_compressed_linenumber_size);
1253   }
1254   // Copy method_parameters
1255   if (method_parameters_len > 0) {
1256     memcpy(newm->method_parameters_start(),
1257            m->method_parameters_start(),
1258            method_parameters_len * sizeof(MethodParametersElement));
1259   }
1260   // Copy checked_exceptions
1261   if (checked_exceptions_len > 0) {
1262     memcpy(newm->checked_exceptions_start(),
1263            m->checked_exceptions_start(),
1264            checked_exceptions_len * sizeof(CheckedExceptionElement));
1265   }
1266   // Copy exception table
1267   if (exception_table_len > 0) {
1268     memcpy(newm->exception_table_start(),
1269            m->exception_table_start(),
1270            exception_table_len * sizeof(ExceptionTableElement));
1271   }
1272   // Copy local variable number table
1273   if (localvariable_len > 0) {
1274     memcpy(newm->localvariable_table_start(),
1275            m->localvariable_table_start(),
1276            localvariable_len * sizeof(LocalVariableTableElement));
1277   }
1278   // Copy stackmap table
1279   if (m->has_stackmap_table()) {
1280     int code_attribute_length = m->stackmap_data()->length();
1281     Array<u1>* stackmap_data =
1282       MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1283     memcpy((void*)stackmap_data->adr_at(0),
1284            (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1285     newm->set_stackmap_data(stackmap_data);
1286   }
1287 
1288   // copy annotations over to new method
1289   newcm->copy_annotations_from(cm);
1290   return newm;
1291 }
1292 
1293 vmSymbols::SID Method::klass_id_for_intrinsics(Klass* holder) {
1294   // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1295   // because we are not loading from core libraries
1296   // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1297   // which does not use the class default class loader so we check for its loader here
1298   InstanceKlass* ik = InstanceKlass::cast(holder);
1299   if ((ik->class_loader() != NULL) && !SystemDictionary::is_ext_class_loader(ik->class_loader())) {
1300     return vmSymbols::NO_SID;   // regardless of name, no intrinsics here
1301   }
1302 
1303   // see if the klass name is well-known:
1304   Symbol* klass_name = ik->name();
1305   return vmSymbols::find_sid(klass_name);
1306 }
1307 
1308 void Method::init_intrinsic_id() {
1309   assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1310   const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1311   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1312   assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1313 
1314   // the klass name is well-known:
1315   vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1316   assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1317 
1318   // ditto for method and signature:
1319   vmSymbols::SID  name_id = vmSymbols::find_sid(name());
1320   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1321       && name_id == vmSymbols::NO_SID)
1322     return;
1323   vmSymbols::SID   sig_id = vmSymbols::find_sid(signature());
1324   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1325       && sig_id == vmSymbols::NO_SID)  return;
1326   jshort flags = access_flags().as_short();
1327 
1328   vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1329   if (id != vmIntrinsics::_none) {
1330     set_intrinsic_id(id);
1331     if (id == vmIntrinsics::_Class_cast) {
1332       // Even if the intrinsic is rejected, we want to inline this simple method.
1333       set_force_inline(true);
1334     }
1335     return;
1336   }
1337 
1338   // A few slightly irregular cases:
1339   switch (klass_id) {
1340   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1341     // Second chance: check in regular Math.
1342     switch (name_id) {
1343     case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1344     case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1345     case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1346       // pretend it is the corresponding method in the non-strict class:
1347       klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1348       id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1349       break;
1350     }
1351     break;
1352 
1353   // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*.
1354   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1355     if (!is_native())  break;
1356     id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1357     if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1358       id = vmIntrinsics::_none;
1359     break;
1360   }
1361 
1362   if (id != vmIntrinsics::_none) {
1363     // Set up its iid.  It is an alias method.
1364     set_intrinsic_id(id);
1365     return;
1366   }
1367 }
1368 
1369 // These two methods are static since a GC may move the Method
1370 bool Method::load_signature_classes(methodHandle m, TRAPS) {
1371   if (!THREAD->can_call_java()) {
1372     // There is nothing useful this routine can do from within the Compile thread.
1373     // Hopefully, the signature contains only well-known classes.
1374     // We could scan for this and return true/false, but the caller won't care.
1375     return false;
1376   }
1377   bool sig_is_loaded = true;
1378   Handle class_loader(THREAD, m->method_holder()->class_loader());
1379   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1380   ResourceMark rm(THREAD);
1381   Symbol*  signature = m->signature();
1382   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1383     if (ss.is_object()) {
1384       Symbol* sym = ss.as_symbol(CHECK_(false));
1385       Symbol*  name  = sym;
1386       Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1387                                              protection_domain, THREAD);
1388       // We are loading classes eagerly. If a ClassNotFoundException or
1389       // a LinkageError was generated, be sure to ignore it.
1390       if (HAS_PENDING_EXCEPTION) {
1391         if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1392             PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1393           CLEAR_PENDING_EXCEPTION;
1394         } else {
1395           return false;
1396         }
1397       }
1398       if( klass == NULL) { sig_is_loaded = false; }
1399     }
1400   }
1401   return sig_is_loaded;
1402 }
1403 
1404 bool Method::has_unloaded_classes_in_signature(methodHandle m, TRAPS) {
1405   Handle class_loader(THREAD, m->method_holder()->class_loader());
1406   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1407   ResourceMark rm(THREAD);
1408   Symbol*  signature = m->signature();
1409   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1410     if (ss.type() == T_OBJECT) {
1411       Symbol* name = ss.as_symbol_or_null();
1412       if (name == NULL) return true;
1413       Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1414       if (klass == NULL) return true;
1415     }
1416   }
1417   return false;
1418 }
1419 
1420 // Exposed so field engineers can debug VM
1421 void Method::print_short_name(outputStream* st) {
1422   ResourceMark rm;
1423 #ifdef PRODUCT
1424   st->print(" %s::", method_holder()->external_name());
1425 #else
1426   st->print(" %s::", method_holder()->internal_name());
1427 #endif
1428   name()->print_symbol_on(st);
1429   if (WizardMode) signature()->print_symbol_on(st);
1430   else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1431     MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1432 }
1433 
1434 // Comparer for sorting an object array containing
1435 // Method*s.
1436 static int method_comparator(Method* a, Method* b) {
1437   return a->name()->fast_compare(b->name());
1438 }
1439 
1440 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1441 // default_methods also uses this without the ordering for fast find_method
1442 void Method::sort_methods(Array<Method*>* methods, bool idempotent, bool set_idnums) {
1443   int length = methods->length();
1444   if (length > 1) {
1445     {
1446       No_Safepoint_Verifier nsv;
1447       QuickSort::sort<Method*>(methods->data(), length, method_comparator, idempotent);
1448     }
1449     // Reset method ordering
1450     if (set_idnums) {
1451       for (int i = 0; i < length; i++) {
1452         Method* m = methods->at(i);
1453         m->set_method_idnum(i);
1454         m->set_orig_method_idnum(i);
1455       }
1456     }
1457   }
1458 }
1459 
1460 //-----------------------------------------------------------------------------------
1461 // Non-product code unless JVM/TI needs it
1462 
1463 #if !defined(PRODUCT) || INCLUDE_JVMTI
1464 class SignatureTypePrinter : public SignatureTypeNames {
1465  private:
1466   outputStream* _st;
1467   bool _use_separator;
1468 
1469   void type_name(const char* name) {
1470     if (_use_separator) _st->print(", ");
1471     _st->print("%s", name);
1472     _use_separator = true;
1473   }
1474 
1475  public:
1476   SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1477     _st = st;
1478     _use_separator = false;
1479   }
1480 
1481   void print_parameters()              { _use_separator = false; iterate_parameters(); }
1482   void print_returntype()              { _use_separator = false; iterate_returntype(); }
1483 };
1484 
1485 
1486 void Method::print_name(outputStream* st) {
1487   Thread *thread = Thread::current();
1488   ResourceMark rm(thread);
1489   st->print("%s ", is_static() ? "static" : "virtual");
1490   if (WizardMode) {
1491     st->print("%s.", method_holder()->internal_name());
1492     name()->print_symbol_on(st);
1493     signature()->print_symbol_on(st);
1494   } else {
1495     SignatureTypePrinter sig(signature(), st);
1496     sig.print_returntype();
1497     st->print(" %s.", method_holder()->internal_name());
1498     name()->print_symbol_on(st);
1499     st->print("(");
1500     sig.print_parameters();
1501     st->print(")");
1502   }
1503 }
1504 #endif // !PRODUCT || INCLUDE_JVMTI
1505 
1506 
1507 void Method::print_codes_on(outputStream* st) const {
1508   print_codes_on(0, code_size(), st);
1509 }
1510 
1511 void Method::print_codes_on(int from, int to, outputStream* st) const {
1512   Thread *thread = Thread::current();
1513   ResourceMark rm(thread);
1514   methodHandle mh (thread, (Method*)this);
1515   BytecodeStream s(mh);
1516   s.set_interval(from, to);
1517   BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1518   while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1519 }
1520 
1521 
1522 // Simple compression of line number tables. We use a regular compressed stream, except that we compress deltas
1523 // between (bci,line) pairs since they are smaller. If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
1524 // we save it as one byte, otherwise we write a 0xFF escape character and use regular compression. 0x0 is used
1525 // as end-of-stream terminator.
1526 
1527 void CompressedLineNumberWriteStream::write_pair_regular(int bci_delta, int line_delta) {
1528   // bci and line number does not compress into single byte.
1529   // Write out escape character and use regular compression for bci and line number.
1530   write_byte((jubyte)0xFF);
1531   write_signed_int(bci_delta);
1532   write_signed_int(line_delta);
1533 }
1534 
1535 // See comment in method.hpp which explains why this exists.
1536 #if defined(_M_AMD64) && _MSC_VER >= 1400
1537 #pragma optimize("", off)
1538 void CompressedLineNumberWriteStream::write_pair(int bci, int line) {
1539   write_pair_inline(bci, line);
1540 }
1541 #pragma optimize("", on)
1542 #endif
1543 
1544 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1545   _bci = 0;
1546   _line = 0;
1547 };
1548 
1549 
1550 bool CompressedLineNumberReadStream::read_pair() {
1551   jubyte next = read_byte();
1552   // Check for terminator
1553   if (next == 0) return false;
1554   if (next == 0xFF) {
1555     // Escape character, regular compression used
1556     _bci  += read_signed_int();
1557     _line += read_signed_int();
1558   } else {
1559     // Single byte compression used
1560     _bci  += next >> 3;
1561     _line += next & 0x7;
1562   }
1563   return true;
1564 }
1565 
1566 
1567 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1568   BreakpointInfo* bp = method_holder()->breakpoints();
1569   for (; bp != NULL; bp = bp->next()) {
1570     if (bp->match(this, bci)) {
1571       return bp->orig_bytecode();
1572     }
1573   }
1574   {
1575     ResourceMark rm;
1576     fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1577   }
1578   return Bytecodes::_shouldnotreachhere;
1579 }
1580 
1581 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1582   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1583   BreakpointInfo* bp = method_holder()->breakpoints();
1584   for (; bp != NULL; bp = bp->next()) {
1585     if (bp->match(this, bci)) {
1586       bp->set_orig_bytecode(code);
1587       // and continue, in case there is more than one
1588     }
1589   }
1590 }
1591 
1592 void Method::set_breakpoint(int bci) {
1593   InstanceKlass* ik = method_holder();
1594   BreakpointInfo *bp = new BreakpointInfo(this, bci);
1595   bp->set_next(ik->breakpoints());
1596   ik->set_breakpoints(bp);
1597   // do this last:
1598   bp->set(this);
1599 }
1600 
1601 static void clear_matches(Method* m, int bci) {
1602   InstanceKlass* ik = m->method_holder();
1603   BreakpointInfo* prev_bp = NULL;
1604   BreakpointInfo* next_bp;
1605   for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1606     next_bp = bp->next();
1607     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1608     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1609       // do this first:
1610       bp->clear(m);
1611       // unhook it
1612       if (prev_bp != NULL)
1613         prev_bp->set_next(next_bp);
1614       else
1615         ik->set_breakpoints(next_bp);
1616       delete bp;
1617       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1618       // at same location. So we have multiple matching (method_index and bci)
1619       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1620       // breakpoint for clear_breakpoint request and keep all other method versions
1621       // BreakpointInfo for future clear_breakpoint request.
1622       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1623       // which is being called when class is unloaded. We delete all the Breakpoint
1624       // information for all versions of method. We may not correctly restore the original
1625       // bytecode in all method versions, but that is ok. Because the class is being unloaded
1626       // so these methods won't be used anymore.
1627       if (bci >= 0) {
1628         break;
1629       }
1630     } else {
1631       // This one is a keeper.
1632       prev_bp = bp;
1633     }
1634   }
1635 }
1636 
1637 void Method::clear_breakpoint(int bci) {
1638   assert(bci >= 0, "");
1639   clear_matches(this, bci);
1640 }
1641 
1642 void Method::clear_all_breakpoints() {
1643   clear_matches(this, -1);
1644 }
1645 
1646 
1647 int Method::invocation_count() {
1648   MethodCounters *mcs = method_counters();
1649   if (TieredCompilation) {
1650     MethodData* const mdo = method_data();
1651     if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1652         ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1653       return InvocationCounter::count_limit;
1654     } else {
1655       return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1656              ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1657     }
1658   } else {
1659     return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1660   }
1661 }
1662 
1663 int Method::backedge_count() {
1664   MethodCounters *mcs = method_counters();
1665   if (TieredCompilation) {
1666     MethodData* const mdo = method_data();
1667     if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1668         ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1669       return InvocationCounter::count_limit;
1670     } else {
1671       return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1672              ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1673     }
1674   } else {
1675     return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1676   }
1677 }
1678 
1679 int Method::highest_comp_level() const {
1680   const MethodCounters* mcs = method_counters();
1681   if (mcs != NULL) {
1682     return mcs->highest_comp_level();
1683   } else {
1684     return CompLevel_none;
1685   }
1686 }
1687 
1688 int Method::highest_osr_comp_level() const {
1689   const MethodCounters* mcs = method_counters();
1690   if (mcs != NULL) {
1691     return mcs->highest_osr_comp_level();
1692   } else {
1693     return CompLevel_none;
1694   }
1695 }
1696 
1697 void Method::set_highest_comp_level(int level) {
1698   MethodCounters* mcs = method_counters();
1699   if (mcs != NULL) {
1700     mcs->set_highest_comp_level(level);
1701   }
1702 }
1703 
1704 void Method::set_highest_osr_comp_level(int level) {
1705   MethodCounters* mcs = method_counters();
1706   if (mcs != NULL) {
1707     mcs->set_highest_osr_comp_level(level);
1708   }
1709 }
1710 
1711 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1712   _bci = bci;
1713   _name_index = m->name_index();
1714   _signature_index = m->signature_index();
1715   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1716   if (_orig_bytecode == Bytecodes::_breakpoint)
1717     _orig_bytecode = m->orig_bytecode_at(_bci);
1718   _next = NULL;
1719 }
1720 
1721 void BreakpointInfo::set(Method* method) {
1722 #ifdef ASSERT
1723   {
1724     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
1725     if (code == Bytecodes::_breakpoint)
1726       code = method->orig_bytecode_at(_bci);
1727     assert(orig_bytecode() == code, "original bytecode must be the same");
1728   }
1729 #endif
1730   Thread *thread = Thread::current();
1731   *method->bcp_from(_bci) = Bytecodes::_breakpoint;
1732   method->incr_number_of_breakpoints(thread);
1733   SystemDictionary::notice_modification();
1734   {
1735     // Deoptimize all dependents on this method
1736     HandleMark hm(thread);
1737     methodHandle mh(thread, method);
1738     CodeCache::flush_dependents_on_method(mh);
1739   }
1740 }
1741 
1742 void BreakpointInfo::clear(Method* method) {
1743   *method->bcp_from(_bci) = orig_bytecode();
1744   assert(method->number_of_breakpoints() > 0, "must not go negative");
1745   method->decr_number_of_breakpoints(Thread::current());
1746 }
1747 
1748 // jmethodID handling
1749 
1750 // This is a block allocating object, sort of like JNIHandleBlock, only a
1751 // lot simpler.
1752 // It's allocated on the CHeap because once we allocate a jmethodID, we can
1753 // never get rid of it.
1754 
1755 static const int min_block_size = 8;
1756 
1757 class JNIMethodBlockNode : public CHeapObj<mtClass> {
1758   friend class JNIMethodBlock;
1759   Method**        _methods;
1760   int             _number_of_methods;
1761   int             _top;
1762   JNIMethodBlockNode* _next;
1763 
1764  public:
1765 
1766   JNIMethodBlockNode(int num_methods = min_block_size);
1767 
1768   ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
1769 
1770   void ensure_methods(int num_addl_methods) {
1771     if (_top < _number_of_methods) {
1772       num_addl_methods -= _number_of_methods - _top;
1773       if (num_addl_methods <= 0) {
1774         return;
1775       }
1776     }
1777     if (_next == NULL) {
1778       _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
1779     } else {
1780       _next->ensure_methods(num_addl_methods);
1781     }
1782   }
1783 };
1784 
1785 class JNIMethodBlock : public CHeapObj<mtClass> {
1786   JNIMethodBlockNode _head;
1787   JNIMethodBlockNode *_last_free;
1788  public:
1789   static Method* const _free_method;
1790 
1791   JNIMethodBlock(int initial_capacity = min_block_size)
1792       : _head(initial_capacity), _last_free(&_head) {}
1793 
1794   void ensure_methods(int num_addl_methods) {
1795     _last_free->ensure_methods(num_addl_methods);
1796   }
1797 
1798   Method** add_method(Method* m) {
1799     for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
1800       if (b->_top < b->_number_of_methods) {
1801         // top points to the next free entry.
1802         int i = b->_top;
1803         b->_methods[i] = m;
1804         b->_top++;
1805         _last_free = b;
1806         return &(b->_methods[i]);
1807       } else if (b->_top == b->_number_of_methods) {
1808         // if the next free entry ran off the block see if there's a free entry
1809         for (int i = 0; i < b->_number_of_methods; i++) {
1810           if (b->_methods[i] == _free_method) {
1811             b->_methods[i] = m;
1812             _last_free = b;
1813             return &(b->_methods[i]);
1814           }
1815         }
1816         // Only check each block once for frees.  They're very unlikely.
1817         // Increment top past the end of the block.
1818         b->_top++;
1819       }
1820       // need to allocate a next block.
1821       if (b->_next == NULL) {
1822         b->_next = _last_free = new JNIMethodBlockNode();
1823       }
1824     }
1825     guarantee(false, "Should always allocate a free block");
1826     return NULL;
1827   }
1828 
1829   bool contains(Method** m) {
1830     if (m == NULL) return false;
1831     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
1832       if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
1833         // This is a bit of extra checking, for two reasons.  One is
1834         // that contains() deals with pointers that are passed in by
1835         // JNI code, so making sure that the pointer is aligned
1836         // correctly is valuable.  The other is that <= and > are
1837         // technically not defined on pointers, so the if guard can
1838         // pass spuriously; no modern compiler is likely to make that
1839         // a problem, though (and if one did, the guard could also
1840         // fail spuriously, which would be bad).
1841         ptrdiff_t idx = m - b->_methods;
1842         if (b->_methods + idx == m) {
1843           return true;
1844         }
1845       }
1846     }
1847     return false;  // not found
1848   }
1849 
1850   // Doesn't really destroy it, just marks it as free so it can be reused.
1851   void destroy_method(Method** m) {
1852 #ifdef ASSERT
1853     assert(contains(m), "should be a methodID");
1854 #endif // ASSERT
1855     *m = _free_method;
1856   }
1857 
1858   // During class unloading the methods are cleared, which is different
1859   // than freed.
1860   void clear_all_methods() {
1861     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
1862       for (int i = 0; i< b->_number_of_methods; i++) {
1863         b->_methods[i] = NULL;
1864       }
1865     }
1866   }
1867 #ifndef PRODUCT
1868   int count_methods() {
1869     // count all allocated methods
1870     int count = 0;
1871     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
1872       for (int i = 0; i< b->_number_of_methods; i++) {
1873         if (b->_methods[i] != _free_method) count++;
1874       }
1875     }
1876     return count;
1877   }
1878 #endif // PRODUCT
1879 };
1880 
1881 // Something that can't be mistaken for an address or a markOop
1882 Method* const JNIMethodBlock::_free_method = (Method*)55;
1883 
1884 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _next(NULL), _top(0) {
1885   _number_of_methods = MAX2(num_methods, min_block_size);
1886   _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
1887   for (int i = 0; i < _number_of_methods; i++) {
1888     _methods[i] = JNIMethodBlock::_free_method;
1889   }
1890 }
1891 
1892 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
1893   ClassLoaderData* cld = loader_data;
1894   if (!SafepointSynchronize::is_at_safepoint()) {
1895     // Have to add jmethod_ids() to class loader data thread-safely.
1896     // Also have to add the method to the list safely, which the cld lock
1897     // protects as well.
1898     MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
1899     if (cld->jmethod_ids() == NULL) {
1900       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
1901     } else {
1902       cld->jmethod_ids()->ensure_methods(capacity);
1903     }
1904   } else {
1905     // At safepoint, we are single threaded and can set this.
1906     if (cld->jmethod_ids() == NULL) {
1907       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
1908     } else {
1909       cld->jmethod_ids()->ensure_methods(capacity);
1910     }
1911   }
1912 }
1913 
1914 // Add a method id to the jmethod_ids
1915 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
1916   ClassLoaderData* cld = loader_data;
1917 
1918   if (!SafepointSynchronize::is_at_safepoint()) {
1919     // Have to add jmethod_ids() to class loader data thread-safely.
1920     // Also have to add the method to the list safely, which the cld lock
1921     // protects as well.
1922     MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
1923     if (cld->jmethod_ids() == NULL) {
1924       cld->set_jmethod_ids(new JNIMethodBlock());
1925     }
1926     // jmethodID is a pointer to Method*
1927     return (jmethodID)cld->jmethod_ids()->add_method(m);
1928   } else {
1929     // At safepoint, we are single threaded and can set this.
1930     if (cld->jmethod_ids() == NULL) {
1931       cld->set_jmethod_ids(new JNIMethodBlock());
1932     }
1933     // jmethodID is a pointer to Method*
1934     return (jmethodID)cld->jmethod_ids()->add_method(m);
1935   }
1936 }
1937 
1938 // Mark a jmethodID as free.  This is called when there is a data race in
1939 // InstanceKlass while creating the jmethodID cache.
1940 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
1941   ClassLoaderData* cld = loader_data;
1942   Method** ptr = (Method**)m;
1943   assert(cld->jmethod_ids() != NULL, "should have method handles");
1944   cld->jmethod_ids()->destroy_method(ptr);
1945 }
1946 
1947 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
1948   // Can't assert the method_holder is the same because the new method has the
1949   // scratch method holder.
1950   assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
1951            == new_method->method_holder()->class_loader(),
1952          "changing to a different class loader");
1953   // Just change the method in place, jmethodID pointer doesn't change.
1954   *((Method**)jmid) = new_method;
1955 }
1956 
1957 bool Method::is_method_id(jmethodID mid) {
1958   Method* m = resolve_jmethod_id(mid);
1959   assert(m != NULL, "should be called with non-null method");
1960   InstanceKlass* ik = m->method_holder();
1961   ClassLoaderData* cld = ik->class_loader_data();
1962   if (cld->jmethod_ids() == NULL) return false;
1963   return (cld->jmethod_ids()->contains((Method**)mid));
1964 }
1965 
1966 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
1967   if (mid == NULL) return NULL;
1968   Method* o = resolve_jmethod_id(mid);
1969   if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
1970     return NULL;
1971   }
1972   return o;
1973 };
1974 
1975 void Method::set_on_stack(const bool value) {
1976   // Set both the method itself and its constant pool.  The constant pool
1977   // on stack means some method referring to it is also on the stack.
1978   constants()->set_on_stack(value);
1979 
1980   bool already_set = on_stack();
1981   _access_flags.set_on_stack(value);
1982   if (value && !already_set) {
1983     MetadataOnStackMark::record(this);
1984   }
1985 }
1986 
1987 // Called when the class loader is unloaded to make all methods weak.
1988 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
1989   loader_data->jmethod_ids()->clear_all_methods();
1990 }
1991 
1992 bool Method::has_method_vptr(const void* ptr) {
1993   Method m;
1994   // This assumes that the vtbl pointer is the first word of a C++ object.
1995   // This assumption is also in universe.cpp patch_klass_vtble
1996   void* vtbl2 = dereference_vptr((const void*)&m);
1997   void* this_vtbl = dereference_vptr(ptr);
1998   return vtbl2 == this_vtbl;
1999 }
2000 
2001 // Check that this pointer is valid by checking that the vtbl pointer matches
2002 bool Method::is_valid_method() const {
2003   if (this == NULL) {
2004     return false;
2005   } else if (!is_metaspace_object()) {
2006     return false;
2007   } else {
2008     return has_method_vptr((const void*)this);
2009   }
2010 }
2011 
2012 #ifndef PRODUCT
2013 void Method::print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) {
2014   out->print_cr("jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2015 }
2016 #endif // PRODUCT
2017 
2018 
2019 // Printing
2020 
2021 #ifndef PRODUCT
2022 
2023 void Method::print_on(outputStream* st) const {
2024   ResourceMark rm;
2025   assert(is_method(), "must be method");
2026   st->print_cr("%s", internal_name());
2027   // get the effect of PrintOopAddress, always, for methods:
2028   st->print_cr(" - this oop:          " INTPTR_FORMAT, p2i(this));
2029   st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();
2030   st->print   (" - constants:         " INTPTR_FORMAT " ", p2i(constants()));
2031   constants()->print_value_on(st); st->cr();
2032   st->print   (" - access:            0x%x  ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2033   st->print   (" - name:              ");    name()->print_value_on(st); st->cr();
2034   st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();
2035   st->print_cr(" - max stack:         %d",   max_stack());
2036   st->print_cr(" - max locals:        %d",   max_locals());
2037   st->print_cr(" - size of params:    %d",   size_of_parameters());
2038   st->print_cr(" - method size:       %d",   method_size());
2039   if (intrinsic_id() != vmIntrinsics::_none)
2040     st->print_cr(" - intrinsic id:      %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
2041   if (highest_comp_level() != CompLevel_none)
2042     st->print_cr(" - highest level:     %d", highest_comp_level());
2043   st->print_cr(" - vtable index:      %d",   _vtable_index);
2044   st->print_cr(" - i2i entry:         " INTPTR_FORMAT, p2i(interpreter_entry()));
2045   st->print(   " - adapters:          ");
2046   AdapterHandlerEntry* a = ((Method*)this)->adapter();
2047   if (a == NULL)
2048     st->print_cr(INTPTR_FORMAT, p2i(a));
2049   else
2050     a->print_adapter_on(st);
2051   st->print_cr(" - compiled entry     " INTPTR_FORMAT, p2i(from_compiled_entry()));
2052   st->print_cr(" - code size:         %d",   code_size());
2053   if (code_size() != 0) {
2054     st->print_cr(" - code start:        " INTPTR_FORMAT, p2i(code_base()));
2055     st->print_cr(" - code end (excl):   " INTPTR_FORMAT, p2i(code_base() + code_size()));
2056   }
2057   if (method_data() != NULL) {
2058     st->print_cr(" - method data:       " INTPTR_FORMAT, p2i(method_data()));
2059   }
2060   st->print_cr(" - checked ex length: %d",   checked_exceptions_length());
2061   if (checked_exceptions_length() > 0) {
2062     CheckedExceptionElement* table = checked_exceptions_start();
2063     st->print_cr(" - checked ex start:  " INTPTR_FORMAT, p2i(table));
2064     if (Verbose) {
2065       for (int i = 0; i < checked_exceptions_length(); i++) {
2066         st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2067       }
2068     }
2069   }
2070   if (has_linenumber_table()) {
2071     u_char* table = compressed_linenumber_table();
2072     st->print_cr(" - linenumber start:  " INTPTR_FORMAT, p2i(table));
2073     if (Verbose) {
2074       CompressedLineNumberReadStream stream(table);
2075       while (stream.read_pair()) {
2076         st->print_cr("   - line %d: %d", stream.line(), stream.bci());
2077       }
2078     }
2079   }
2080   st->print_cr(" - localvar length:   %d",   localvariable_table_length());
2081   if (localvariable_table_length() > 0) {
2082     LocalVariableTableElement* table = localvariable_table_start();
2083     st->print_cr(" - localvar start:    " INTPTR_FORMAT, p2i(table));
2084     if (Verbose) {
2085       for (int i = 0; i < localvariable_table_length(); i++) {
2086         int bci = table[i].start_bci;
2087         int len = table[i].length;
2088         const char* name = constants()->printable_name_at(table[i].name_cp_index);
2089         const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2090         int slot = table[i].slot;
2091         st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2092       }
2093     }
2094   }
2095   if (code() != NULL) {
2096     st->print   (" - compiled code: ");
2097     code()->print_value_on(st);
2098   }
2099   if (is_native()) {
2100     st->print_cr(" - native function:   " INTPTR_FORMAT, p2i(native_function()));
2101     st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2102   }
2103 }
2104 
2105 #endif //PRODUCT
2106 
2107 void Method::print_value_on(outputStream* st) const {
2108   assert(is_method(), "must be method");
2109   st->print("%s", internal_name());
2110   print_address_on(st);
2111   st->print(" ");
2112   name()->print_value_on(st);
2113   st->print(" ");
2114   signature()->print_value_on(st);
2115   st->print(" in ");
2116   method_holder()->print_value_on(st);
2117   if (WizardMode) st->print("#%d", _vtable_index);
2118   if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2119   if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2120 }
2121 
2122 #if INCLUDE_SERVICES
2123 // Size Statistics
2124 void Method::collect_statistics(KlassSizeStats *sz) const {
2125   int mysize = sz->count(this);
2126   sz->_method_bytes += mysize;
2127   sz->_method_all_bytes += mysize;
2128   sz->_rw_bytes += mysize;
2129 
2130   if (constMethod()) {
2131     constMethod()->collect_statistics(sz);
2132   }
2133   if (method_data()) {
2134     method_data()->collect_statistics(sz);
2135   }
2136 }
2137 #endif // INCLUDE_SERVICES
2138 
2139 // LogTouchedMethods and PrintTouchedMethods
2140 
2141 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2142 // the Method may be garbage collected. Let's roll our own hash table.
2143 class TouchedMethodRecord : CHeapObj<mtTracing> {
2144 public:
2145   // It's OK to store Symbols here because they will NOT be GC'ed if
2146   // LogTouchedMethods is enabled.
2147   TouchedMethodRecord* _next;
2148   Symbol* _class_name;
2149   Symbol* _method_name;
2150   Symbol* _method_signature;
2151 };
2152 
2153 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2154 static TouchedMethodRecord** _touched_method_table = NULL;
2155 
2156 void Method::log_touched(TRAPS) {
2157 
2158   const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2159   Symbol* my_class = klass_name();
2160   Symbol* my_name  = name();
2161   Symbol* my_sig   = signature();
2162 
2163   unsigned int hash = my_class->identity_hash() +
2164                       my_name->identity_hash() +
2165                       my_sig->identity_hash();
2166   juint index = juint(hash) % table_size;
2167 
2168   MutexLocker ml(TouchedMethodLog_lock, THREAD);
2169   if (_touched_method_table == NULL) {
2170     _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2171                                               mtTracing, CURRENT_PC);
2172     memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2173   }
2174 
2175   TouchedMethodRecord* ptr = _touched_method_table[index];
2176   while (ptr) {
2177     if (ptr->_class_name       == my_class &&
2178         ptr->_method_name      == my_name &&
2179         ptr->_method_signature == my_sig) {
2180       return;
2181     }
2182     if (ptr->_next == NULL) break;
2183     ptr = ptr->_next;
2184   }
2185   TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2186   my_class->set_permanent();  // prevent reclaimed by GC
2187   my_name->set_permanent();
2188   my_sig->set_permanent();
2189   nptr->_class_name         = my_class;
2190   nptr->_method_name        = my_name;
2191   nptr->_method_signature   = my_sig;
2192   nptr->_next               = NULL;
2193 
2194   if (ptr == NULL) {
2195     // first
2196     _touched_method_table[index] = nptr;
2197   } else {
2198     ptr->_next = nptr;
2199   }
2200 }
2201 
2202 void Method::print_touched_methods(outputStream* out) {
2203   MutexLockerEx ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2204   out->print_cr("# Method::print_touched_methods version 1");
2205   if (_touched_method_table) {
2206     for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2207       TouchedMethodRecord* ptr = _touched_method_table[i];
2208       while(ptr) {
2209         ptr->_class_name->print_symbol_on(out);       out->print(".");
2210         ptr->_method_name->print_symbol_on(out);      out->print(":");
2211         ptr->_method_signature->print_symbol_on(out); out->cr();
2212         ptr = ptr->_next;
2213       }
2214     }
2215   }
2216 }
2217 
2218 // Verification
2219 
2220 void Method::verify_on(outputStream* st) {
2221   guarantee(is_method(), "object must be method");
2222   guarantee(constants()->is_constantPool(), "should be constant pool");
2223   guarantee(constMethod()->is_constMethod(), "should be ConstMethod*");
2224   MethodData* md = method_data();
2225   guarantee(md == NULL ||
2226       md->is_methodData(), "should be method data");
2227 }