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 "memory/universe.hpp"
  45 #include "oops/constMethod.hpp"
  46 #include "oops/constantPool.hpp"
  47 #include "oops/method.inline.hpp"
  48 #include "oops/methodData.hpp"
  49 #include "oops/objArrayKlass.hpp"
  50 #include "oops/objArrayOop.inline.hpp"
  51 #include "oops/oop.inline.hpp"
  52 #include "oops/symbol.hpp"
  53 #include "prims/jvmtiExport.hpp"
  54 #include "prims/methodHandles.hpp"
  55 #include "prims/nativeLookup.hpp"
  56 #include "runtime/arguments.hpp"
  57 #include "runtime/compilationPolicy.hpp"
  58 #include "runtime/frame.inline.hpp"
  59 #include "runtime/handles.inline.hpp"
  60 #include "runtime/init.hpp"
  61 #include "runtime/orderAccess.hpp"
  62 #include "runtime/relocator.hpp"
  63 #include "runtime/safepointVerifiers.hpp"
  64 #include "runtime/sharedRuntime.hpp"
  65 #include "runtime/signature.hpp"
  66 #include "utilities/align.hpp"
  67 #include "utilities/quickSort.hpp"
  68 #include "utilities/vmError.hpp"
  69 #include "utilities/xmlstream.hpp"
  70 
  71 // Implementation of Method
  72 
  73 Method* Method::allocate(ClassLoaderData* loader_data,
  74                          int byte_code_size,
  75                          AccessFlags access_flags,
  76                          InlineTableSizes* sizes,
  77                          ConstMethod::MethodType method_type,
  78                          TRAPS) {
  79   assert(!access_flags.is_native() || byte_code_size == 0,
  80          "native methods should not contain byte codes");
  81   ConstMethod* cm = ConstMethod::allocate(loader_data,
  82                                           byte_code_size,
  83                                           sizes,
  84                                           method_type,
  85                                           CHECK_NULL);
  86   int size = Method::size(access_flags.is_native());
  87   return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
  88 }
  89 
  90 Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
  91   NoSafepointVerifier no_safepoint;
  92   set_constMethod(xconst);
  93   set_access_flags(access_flags);
  94   set_intrinsic_id(vmIntrinsics::_none);
  95   set_force_inline(false);
  96   set_hidden(false);
  97   set_dont_inline(false);
  98   set_has_injected_profile(false);
  99   set_method_data(NULL);
 100   clear_method_counters();
 101   set_vtable_index(Method::garbage_vtable_index);
 102 
 103   // Fix and bury in Method*
 104   set_interpreter_entry(NULL); // sets i2i entry and from_int
 105   set_adapter_entry(NULL);
 106   clear_code(false /* don't need a lock */); // from_c/from_i get set to c2i/i2i
 107 
 108   if (access_flags.is_native()) {
 109     clear_native_function();
 110     set_signature_handler(NULL);
 111   }
 112 
 113   NOT_PRODUCT(set_compiled_invocation_count(0);)
 114 }
 115 
 116 // Release Method*.  The nmethod will be gone when we get here because
 117 // we've walked the code cache.
 118 void Method::deallocate_contents(ClassLoaderData* loader_data) {
 119   MetadataFactory::free_metadata(loader_data, constMethod());
 120   set_constMethod(NULL);
 121 #if INCLUDE_JVMCI
 122   if (method_data()) {
 123     FailedSpeculation::free_failed_speculations(method_data()->get_failed_speculations_address());
 124   }
 125 #endif
 126   MetadataFactory::free_metadata(loader_data, method_data());
 127   set_method_data(NULL);
 128   MetadataFactory::free_metadata(loader_data, method_counters());
 129   clear_method_counters();
 130   // The nmethod will be gone when we get here.
 131   if (code() != NULL) _code = NULL;
 132 }
 133 
 134 address Method::get_i2c_entry() {
 135   assert(adapter() != NULL, "must have");
 136   return adapter()->get_i2c_entry();
 137 }
 138 
 139 address Method::get_c2i_entry() {
 140   assert(adapter() != NULL, "must have");
 141   return adapter()->get_c2i_entry();
 142 }
 143 
 144 address Method::get_c2i_unverified_entry() {
 145   assert(adapter() != NULL, "must have");
 146   return adapter()->get_c2i_unverified_entry();
 147 }
 148 
 149 address Method::get_c2i_no_clinit_check_entry() {
 150   assert(VM_Version::supports_fast_class_init_checks(), "");
 151   assert(adapter() != NULL, "must have");
 152   return adapter()->get_c2i_no_clinit_check_entry();
 153 }
 154 
 155 char* Method::name_and_sig_as_C_string() const {
 156   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
 157 }
 158 
 159 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
 160   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
 161 }
 162 
 163 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
 164   const char* klass_name = klass->external_name();
 165   int klass_name_len  = (int)strlen(klass_name);
 166   int method_name_len = method_name->utf8_length();
 167   int len             = klass_name_len + 1 + method_name_len + signature->utf8_length();
 168   char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);
 169   strcpy(dest, klass_name);
 170   dest[klass_name_len] = '.';
 171   strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
 172   strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
 173   dest[len] = 0;
 174   return dest;
 175 }
 176 
 177 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
 178   Symbol* klass_name = klass->name();
 179   klass_name->as_klass_external_name(buf, size);
 180   int len = (int)strlen(buf);
 181 
 182   if (len < size - 1) {
 183     buf[len++] = '.';
 184 
 185     method_name->as_C_string(&(buf[len]), size - len);
 186     len = (int)strlen(buf);
 187 
 188     signature->as_C_string(&(buf[len]), size - len);
 189   }
 190 
 191   return buf;
 192 }
 193 
 194 const char* Method::external_name() const {
 195   return external_name(constants()->pool_holder(), name(), signature());
 196 }
 197 
 198 void Method::print_external_name(outputStream *os) const {
 199   print_external_name(os, constants()->pool_holder(), name(), signature());
 200 }
 201 
 202 const char* Method::external_name(Klass* klass, Symbol* method_name, Symbol* signature) {
 203   stringStream ss;
 204   print_external_name(&ss, klass, method_name, signature);
 205   return ss.as_string();
 206 }
 207 
 208 void Method::print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature) {
 209   signature->print_as_signature_external_return_type(os);
 210   os->print(" %s.%s(", klass->external_name(), method_name->as_C_string());
 211   signature->print_as_signature_external_parameters(os);
 212   os->print(")");
 213 }
 214 
 215 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
 216   // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
 217   // access exception table
 218   ExceptionTable table(mh());
 219   int length = table.length();
 220   // iterate through all entries sequentially
 221   constantPoolHandle pool(THREAD, mh->constants());
 222   for (int i = 0; i < length; i ++) {
 223     //reacquire the table in case a GC happened
 224     ExceptionTable table(mh());
 225     int beg_bci = table.start_pc(i);
 226     int end_bci = table.end_pc(i);
 227     assert(beg_bci <= end_bci, "inconsistent exception table");
 228     if (beg_bci <= throw_bci && throw_bci < end_bci) {
 229       // exception handler bci range covers throw_bci => investigate further
 230       int handler_bci = table.handler_pc(i);
 231       int klass_index = table.catch_type_index(i);
 232       if (klass_index == 0) {
 233         return handler_bci;
 234       } else if (ex_klass == NULL) {
 235         return handler_bci;
 236       } else {
 237         // we know the exception class => get the constraint class
 238         // this may require loading of the constraint class; if verification
 239         // fails or some other exception occurs, return handler_bci
 240         Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
 241         assert(k != NULL, "klass not loaded");
 242         if (ex_klass->is_subtype_of(k)) {
 243           return handler_bci;
 244         }
 245       }
 246     }
 247   }
 248 
 249   return -1;
 250 }
 251 
 252 void Method::mask_for(int bci, InterpreterOopMap* mask) {
 253   methodHandle h_this(Thread::current(), this);
 254   // Only GC uses the OopMapCache during thread stack root scanning
 255   // any other uses generate an oopmap but do not save it in the cache.
 256   if (Universe::heap()->is_gc_active()) {
 257     method_holder()->mask_for(h_this, bci, mask);
 258   } else {
 259     OopMapCache::compute_one_oop_map(h_this, bci, mask);
 260   }
 261   return;
 262 }
 263 
 264 
 265 int Method::bci_from(address bcp) const {
 266   if (is_native() && bcp == 0) {
 267     return 0;
 268   }
 269 #ifdef ASSERT
 270   {
 271     ResourceMark rm;
 272     assert(is_native() && bcp == code_base() || contains(bcp) || VMError::is_error_reported(),
 273            "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
 274            p2i(bcp), name_and_sig_as_C_string());
 275   }
 276 #endif
 277   return bcp - code_base();
 278 }
 279 
 280 
 281 int Method::validate_bci(int bci) const {
 282   return (bci == 0 || bci < code_size()) ? bci : -1;
 283 }
 284 
 285 // Return bci if it appears to be a valid bcp
 286 // Return -1 otherwise.
 287 // Used by profiling code, when invalid data is a possibility.
 288 // The caller is responsible for validating the Method* itself.
 289 int Method::validate_bci_from_bcp(address bcp) const {
 290   // keep bci as -1 if not a valid bci
 291   int bci = -1;
 292   if (bcp == 0 || bcp == code_base()) {
 293     // code_size() may return 0 and we allow 0 here
 294     // the method may be native
 295     bci = 0;
 296   } else if (contains(bcp)) {
 297     bci = bcp - code_base();
 298   }
 299   // Assert that if we have dodged any asserts, bci is negative.
 300   assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
 301   return bci;
 302 }
 303 
 304 address Method::bcp_from(int bci) const {
 305   assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
 306          "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
 307   address bcp = code_base() + bci;
 308   assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
 309   return bcp;
 310 }
 311 
 312 address Method::bcp_from(address bcp) const {
 313   if (is_native() && bcp == NULL) {
 314     return code_base();
 315   } else {
 316     return bcp;
 317   }
 318 }
 319 
 320 int Method::size(bool is_native) {
 321   // If native, then include pointers for native_function and signature_handler
 322   int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
 323   int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
 324   return align_metadata_size(header_size() + extra_words);
 325 }
 326 
 327 
 328 Symbol* Method::klass_name() const {
 329   return method_holder()->name();
 330 }
 331 
 332 
 333 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
 334   log_trace(cds)("Iter(Method): %p", this);
 335 
 336   it->push(&_constMethod);
 337   it->push(&_method_data);
 338   it->push(&_method_counters);
 339 }
 340 
 341 // Attempt to return method oop to original state.  Clear any pointers
 342 // (to objects outside the shared spaces).  We won't be able to predict
 343 // where they should point in a new JVM.  Further initialize some
 344 // entries now in order allow them to be write protected later.
 345 
 346 void Method::remove_unshareable_info() {
 347   unlink_method();
 348 }
 349 
 350 void Method::set_vtable_index(int index) {
 351   if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
 352     // At runtime initialize_vtable is rerun as part of link_class_impl()
 353     // for a shared class loaded by the non-boot loader to obtain the loader
 354     // constraints based on the runtime classloaders' context.
 355     return; // don't write into the shared class
 356   } else {
 357     _vtable_index = index;
 358   }
 359 }
 360 
 361 void Method::set_itable_index(int index) {
 362   if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
 363     // At runtime initialize_itable is rerun as part of link_class_impl()
 364     // for a shared class loaded by the non-boot loader to obtain the loader
 365     // constraints based on the runtime classloaders' context. The dumptime
 366     // itable index should be the same as the runtime index.
 367     assert(_vtable_index == itable_index_max - index,
 368            "archived itable index is different from runtime index");
 369     return; // don’t write into the shared class
 370   } else {
 371     _vtable_index = itable_index_max - index;
 372   }
 373   assert(valid_itable_index(), "");
 374 }
 375 
 376 
 377 
 378 bool Method::was_executed_more_than(int n) {
 379   // Invocation counter is reset when the Method* is compiled.
 380   // If the method has compiled code we therefore assume it has
 381   // be excuted more than n times.
 382   if (is_accessor() || is_empty_method() || (code() != NULL)) {
 383     // interpreter doesn't bump invocation counter of trivial methods
 384     // compiler does not bump invocation counter of compiled methods
 385     return true;
 386   }
 387   else if ((method_counters() != NULL &&
 388             method_counters()->invocation_counter()->carry()) ||
 389            (method_data() != NULL &&
 390             method_data()->invocation_counter()->carry())) {
 391     // The carry bit is set when the counter overflows and causes
 392     // a compilation to occur.  We don't know how many times
 393     // the counter has been reset, so we simply assume it has
 394     // been executed more than n times.
 395     return true;
 396   } else {
 397     return invocation_count() > n;
 398   }
 399 }
 400 
 401 void Method::print_invocation_count() {
 402   if (is_static()) tty->print("static ");
 403   if (is_final()) tty->print("final ");
 404   if (is_synchronized()) tty->print("synchronized ");
 405   if (is_native()) tty->print("native ");
 406   tty->print("%s::", method_holder()->external_name());
 407   name()->print_symbol_on(tty);
 408   signature()->print_symbol_on(tty);
 409 
 410   if (WizardMode) {
 411     // dump the size of the byte codes
 412     tty->print(" {%d}", code_size());
 413   }
 414   tty->cr();
 415 
 416   tty->print_cr ("  interpreter_invocation_count: %8d ", interpreter_invocation_count());
 417   tty->print_cr ("  invocation_counter:           %8d ", invocation_count());
 418   tty->print_cr ("  backedge_counter:             %8d ", backedge_count());
 419 #ifndef PRODUCT
 420   if (CountCompiledCalls) {
 421     tty->print_cr ("  compiled_invocation_count: %8d ", compiled_invocation_count());
 422   }
 423 #endif
 424 }
 425 
 426 // Build a MethodData* object to hold information about this method
 427 // collected in the interpreter.
 428 void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) {
 429   // Do not profile the method if metaspace has hit an OOM previously
 430   // allocating profiling data. Callers clear pending exception so don't
 431   // add one here.
 432   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 433     return;
 434   }
 435 
 436   // Grab a lock here to prevent multiple
 437   // MethodData*s from being created.
 438   MutexLocker ml(MethodData_lock, THREAD);
 439   if (method->method_data() == NULL) {
 440     ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
 441     MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
 442     if (HAS_PENDING_EXCEPTION) {
 443       CompileBroker::log_metaspace_failure();
 444       ClassLoaderDataGraph::set_metaspace_oom(true);
 445       return;   // return the exception (which is cleared)
 446     }
 447 
 448     method->set_method_data(method_data);
 449     if (PrintMethodData && (Verbose || WizardMode)) {
 450       ResourceMark rm(THREAD);
 451       tty->print("build_interpreter_method_data for ");
 452       method->print_name(tty);
 453       tty->cr();
 454       // At the end of the run, the MDO, full of data, will be dumped.
 455     }
 456   }
 457 }
 458 
 459 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
 460   // Do not profile the method if metaspace has hit an OOM previously
 461   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 462     return NULL;
 463   }
 464 
 465   methodHandle mh(m);
 466   MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
 467   if (HAS_PENDING_EXCEPTION) {
 468     CompileBroker::log_metaspace_failure();
 469     ClassLoaderDataGraph::set_metaspace_oom(true);
 470     return NULL;   // return the exception (which is cleared)
 471   }
 472   if (!mh->init_method_counters(counters)) {
 473     MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
 474   }
 475 
 476   if (LogTouchedMethods) {
 477     mh->log_touched(CHECK_NULL);
 478   }
 479 
 480   return mh->method_counters();
 481 }
 482 
 483 bool Method::init_method_counters(MethodCounters* counters) {
 484   // Try to install a pointer to MethodCounters, return true on success.
 485   return Atomic::replace_if_null(counters, &_method_counters);
 486 }
 487 
 488 int Method::extra_stack_words() {
 489   // not an inline function, to avoid a header dependency on Interpreter
 490   return extra_stack_entries() * Interpreter::stackElementSize;
 491 }
 492 
 493 
 494 void Method::compute_size_of_parameters(Thread *thread) {
 495   ArgumentSizeComputer asc(signature());
 496   set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
 497 }
 498 
 499 BasicType Method::result_type() const {
 500   ResultTypeFinder rtf(signature());
 501   return rtf.type();
 502 }
 503 
 504 
 505 bool Method::is_empty_method() const {
 506   return  code_size() == 1
 507       && *code_base() == Bytecodes::_return;
 508 }
 509 
 510 
 511 bool Method::is_vanilla_constructor() const {
 512   // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
 513   // which only calls the superclass vanilla constructor and possibly does stores of
 514   // zero constants to local fields:
 515   //
 516   //   aload_0
 517   //   invokespecial
 518   //   indexbyte1
 519   //   indexbyte2
 520   //
 521   // followed by an (optional) sequence of:
 522   //
 523   //   aload_0
 524   //   aconst_null / iconst_0 / fconst_0 / dconst_0
 525   //   putfield
 526   //   indexbyte1
 527   //   indexbyte2
 528   //
 529   // followed by:
 530   //
 531   //   return
 532 
 533   assert(name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructors");
 534   assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
 535   int size = code_size();
 536   // Check if size match
 537   if (size == 0 || size % 5 != 0) return false;
 538   address cb = code_base();
 539   int last = size - 1;
 540   if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
 541     // Does not call superclass default constructor
 542     return false;
 543   }
 544   // Check optional sequence
 545   for (int i = 4; i < last; i += 5) {
 546     if (cb[i] != Bytecodes::_aload_0) return false;
 547     if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
 548     if (cb[i+2] != Bytecodes::_putfield) return false;
 549   }
 550   return true;
 551 }
 552 
 553 
 554 bool Method::compute_has_loops_flag() {
 555   BytecodeStream bcs(this);
 556   Bytecodes::Code bc;
 557 
 558   while ((bc = bcs.next()) >= 0) {
 559     switch( bc ) {
 560       case Bytecodes::_ifeq:
 561       case Bytecodes::_ifnull:
 562       case Bytecodes::_iflt:
 563       case Bytecodes::_ifle:
 564       case Bytecodes::_ifne:
 565       case Bytecodes::_ifnonnull:
 566       case Bytecodes::_ifgt:
 567       case Bytecodes::_ifge:
 568       case Bytecodes::_if_icmpeq:
 569       case Bytecodes::_if_icmpne:
 570       case Bytecodes::_if_icmplt:
 571       case Bytecodes::_if_icmpgt:
 572       case Bytecodes::_if_icmple:
 573       case Bytecodes::_if_icmpge:
 574       case Bytecodes::_if_acmpeq:
 575       case Bytecodes::_if_acmpne:
 576       case Bytecodes::_goto:
 577       case Bytecodes::_jsr:
 578         if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
 579         break;
 580 
 581       case Bytecodes::_goto_w:
 582       case Bytecodes::_jsr_w:
 583         if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
 584         break;
 585 
 586       default:
 587         break;
 588     }
 589   }
 590   _access_flags.set_loops_flag_init();
 591   return _access_flags.has_loops();
 592 }
 593 
 594 bool Method::is_final_method(AccessFlags class_access_flags) const {
 595   // or "does_not_require_vtable_entry"
 596   // default method or overpass can occur, is not final (reuses vtable entry)
 597   // private methods in classes get vtable entries for backward class compatibility.
 598   if (is_overpass() || is_default_method())  return false;
 599   return is_final() || class_access_flags.is_final();
 600 }
 601 
 602 bool Method::is_final_method() const {
 603   return is_final_method(method_holder()->access_flags());
 604 }
 605 
 606 bool Method::is_default_method() const {
 607   if (method_holder() != NULL &&
 608       method_holder()->is_interface() &&
 609       !is_abstract() && !is_private()) {
 610     return true;
 611   } else {
 612     return false;
 613   }
 614 }
 615 
 616 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
 617   if (is_final_method(class_access_flags))  return true;
 618 #ifdef ASSERT
 619   ResourceMark rm;
 620   bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
 621   if (class_access_flags.is_interface()) {
 622       assert(is_nonv == is_static() || is_nonv == is_private(),
 623              "nonvirtual unexpected for non-static, non-private: %s",
 624              name_and_sig_as_C_string());
 625   }
 626 #endif
 627   assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
 628   return vtable_index() == nonvirtual_vtable_index;
 629 }
 630 
 631 bool Method::can_be_statically_bound() const {
 632   return can_be_statically_bound(method_holder()->access_flags());
 633 }
 634 
 635 bool Method::can_be_statically_bound(InstanceKlass* context) const {
 636   return (method_holder() == context) && can_be_statically_bound();
 637 }
 638 
 639 bool Method::is_accessor() const {
 640   return is_getter() || is_setter();
 641 }
 642 
 643 bool Method::is_getter() const {
 644   if (code_size() != 5) return false;
 645   if (size_of_parameters() != 1) return false;
 646   if (java_code_at(0) != Bytecodes::_aload_0)  return false;
 647   if (java_code_at(1) != Bytecodes::_getfield) return false;
 648   switch (java_code_at(4)) {
 649     case Bytecodes::_ireturn:
 650     case Bytecodes::_lreturn:
 651     case Bytecodes::_freturn:
 652     case Bytecodes::_dreturn:
 653     case Bytecodes::_areturn:
 654       break;
 655     default:
 656       return false;
 657   }
 658   return true;
 659 }
 660 
 661 bool Method::is_setter() const {
 662   if (code_size() != 6) return false;
 663   if (java_code_at(0) != Bytecodes::_aload_0) return false;
 664   switch (java_code_at(1)) {
 665     case Bytecodes::_iload_1:
 666     case Bytecodes::_aload_1:
 667     case Bytecodes::_fload_1:
 668       if (size_of_parameters() != 2) return false;
 669       break;
 670     case Bytecodes::_dload_1:
 671     case Bytecodes::_lload_1:
 672       if (size_of_parameters() != 3) return false;
 673       break;
 674     default:
 675       return false;
 676   }
 677   if (java_code_at(2) != Bytecodes::_putfield) return false;
 678   if (java_code_at(5) != Bytecodes::_return)   return false;
 679   return true;
 680 }
 681 
 682 bool Method::is_constant_getter() const {
 683   int last_index = code_size() - 1;
 684   // Check if the first 1-3 bytecodes are a constant push
 685   // and the last bytecode is a return.
 686   return (2 <= code_size() && code_size() <= 4 &&
 687           Bytecodes::is_const(java_code_at(0)) &&
 688           Bytecodes::length_for(java_code_at(0)) == last_index &&
 689           Bytecodes::is_return(java_code_at(last_index)));
 690 }
 691 
 692 bool Method::is_initializer() const {
 693   return is_object_initializer() || is_static_initializer();
 694 }
 695 
 696 bool Method::has_valid_initializer_flags() const {
 697   return (is_static() ||
 698           method_holder()->major_version() < 51);
 699 }
 700 
 701 bool Method::is_static_initializer() const {
 702   // For classfiles version 51 or greater, ensure that the clinit method is
 703   // static.  Non-static methods with the name "<clinit>" are not static
 704   // initializers. (older classfiles exempted for backward compatibility)
 705   return name() == vmSymbols::class_initializer_name() &&
 706          has_valid_initializer_flags();
 707 }
 708 
 709 bool Method::is_object_initializer() const {
 710    return name() == vmSymbols::object_initializer_name();
 711 }
 712 
 713 bool Method::needs_clinit_barrier() const {
 714   return is_static() && !method_holder()->is_initialized();
 715 }
 716 
 717 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
 718   int length = method->checked_exceptions_length();
 719   if (length == 0) {  // common case
 720     return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
 721   } else {
 722     methodHandle h_this(THREAD, method);
 723     objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
 724     objArrayHandle mirrors (THREAD, m_oop);
 725     for (int i = 0; i < length; i++) {
 726       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
 727       Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
 728       assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
 729       mirrors->obj_at_put(i, k->java_mirror());
 730     }
 731     return mirrors;
 732   }
 733 };
 734 
 735 
 736 int Method::line_number_from_bci(int bci) const {
 737   int best_bci  =  0;
 738   int best_line = -1;
 739   if (bci == SynchronizationEntryBCI) bci = 0;
 740   if (0 <= bci && bci < code_size() && has_linenumber_table()) {
 741     // The line numbers are a short array of 2-tuples [start_pc, line_number].
 742     // Not necessarily sorted and not necessarily one-to-one.
 743     CompressedLineNumberReadStream stream(compressed_linenumber_table());
 744     while (stream.read_pair()) {
 745       if (stream.bci() == bci) {
 746         // perfect match
 747         return stream.line();
 748       } else {
 749         // update best_bci/line
 750         if (stream.bci() < bci && stream.bci() >= best_bci) {
 751           best_bci  = stream.bci();
 752           best_line = stream.line();
 753         }
 754       }
 755     }
 756   }
 757   return best_line;
 758 }
 759 
 760 
 761 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
 762   if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
 763     Thread *thread = Thread::current();
 764     Symbol* klass_name = constants()->klass_name_at(klass_index);
 765     Handle loader(thread, method_holder()->class_loader());
 766     Handle prot  (thread, method_holder()->protection_domain());
 767     return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
 768   } else {
 769     return true;
 770   }
 771 }
 772 
 773 
 774 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
 775   int klass_index = constants()->klass_ref_index_at(refinfo_index);
 776   if (must_be_resolved) {
 777     // Make sure klass is resolved in constantpool.
 778     if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
 779   }
 780   return is_klass_loaded_by_klass_index(klass_index);
 781 }
 782 
 783 
 784 void Method::set_native_function(address function, bool post_event_flag) {
 785   assert(function != NULL, "use clear_native_function to unregister natives");
 786   assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
 787   address* native_function = native_function_addr();
 788 
 789   // We can see racers trying to place the same native function into place. Once
 790   // is plenty.
 791   address current = *native_function;
 792   if (current == function) return;
 793   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
 794       function != NULL) {
 795     // native_method_throw_unsatisfied_link_error_entry() should only
 796     // be passed when post_event_flag is false.
 797     assert(function !=
 798       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 799       "post_event_flag mis-match");
 800 
 801     // post the bind event, and possible change the bind function
 802     JvmtiExport::post_native_method_bind(this, &function);
 803   }
 804   *native_function = function;
 805   // This function can be called more than once. We must make sure that we always
 806   // use the latest registered method -> check if a stub already has been generated.
 807   // If so, we have to make it not_entrant.
 808   CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates
 809   if (nm != NULL) {
 810     nm->make_not_entrant();
 811   }
 812 }
 813 
 814 
 815 bool Method::has_native_function() const {
 816   if (is_method_handle_intrinsic())
 817     return false;  // special-cased in SharedRuntime::generate_native_wrapper
 818   address func = native_function();
 819   return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
 820 }
 821 
 822 
 823 void Method::clear_native_function() {
 824   // Note: is_method_handle_intrinsic() is allowed here.
 825   set_native_function(
 826     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 827     !native_bind_event_is_interesting);
 828   clear_code();
 829 }
 830 
 831 
 832 void Method::set_signature_handler(address handler) {
 833   address* signature_handler =  signature_handler_addr();
 834   *signature_handler = handler;
 835 }
 836 
 837 
 838 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
 839   assert(reason != NULL, "must provide a reason");
 840   if (PrintCompilation && report) {
 841     ttyLocker ttyl;
 842     tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
 843     if (comp_level == CompLevel_all) {
 844       tty->print("all levels ");
 845     } else {
 846       tty->print("level %d ", comp_level);
 847     }
 848     this->print_short_name(tty);
 849     int size = this->code_size();
 850     if (size > 0) {
 851       tty->print(" (%d bytes)", size);
 852     }
 853     if (reason != NULL) {
 854       tty->print("   %s", reason);
 855     }
 856     tty->cr();
 857   }
 858   if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
 859     ttyLocker ttyl;
 860     xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
 861                      os::current_thread_id(), is_osr, comp_level);
 862     if (reason != NULL) {
 863       xtty->print(" reason=\'%s\'", reason);
 864     }
 865     xtty->method(this);
 866     xtty->stamp();
 867     xtty->end_elem();
 868   }
 869 }
 870 
 871 bool Method::is_always_compilable() const {
 872   // Generated adapters must be compiled
 873   if (is_method_handle_intrinsic() && is_synthetic()) {
 874     assert(!is_not_c1_compilable(), "sanity check");
 875     assert(!is_not_c2_compilable(), "sanity check");
 876     return true;
 877   }
 878 
 879   return false;
 880 }
 881 
 882 bool Method::is_not_compilable(int comp_level) const {
 883   if (number_of_breakpoints() > 0)
 884     return true;
 885   if (is_always_compilable())
 886     return false;
 887   if (comp_level == CompLevel_any)
 888     return is_not_c1_compilable() || is_not_c2_compilable();
 889   if (is_c1_compile(comp_level))
 890     return is_not_c1_compilable();
 891   if (is_c2_compile(comp_level))
 892     return is_not_c2_compilable();
 893   return false;
 894 }
 895 
 896 // call this when compiler finds that this method is not compilable
 897 void Method::set_not_compilable(const char* reason, int comp_level, bool report) {
 898   if (is_always_compilable()) {
 899     // Don't mark a method which should be always compilable
 900     return;
 901   }
 902   print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
 903   if (comp_level == CompLevel_all) {
 904     set_not_c1_compilable();
 905     set_not_c2_compilable();
 906   } else {
 907     if (is_c1_compile(comp_level))
 908       set_not_c1_compilable();
 909     if (is_c2_compile(comp_level))
 910       set_not_c2_compilable();
 911   }
 912   CompilationPolicy::policy()->disable_compilation(this);
 913   assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
 914 }
 915 
 916 bool Method::is_not_osr_compilable(int comp_level) const {
 917   if (is_not_compilable(comp_level))
 918     return true;
 919   if (comp_level == CompLevel_any)
 920     return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
 921   if (is_c1_compile(comp_level))
 922     return is_not_c1_osr_compilable();
 923   if (is_c2_compile(comp_level))
 924     return is_not_c2_osr_compilable();
 925   return false;
 926 }
 927 
 928 void Method::set_not_osr_compilable(const char* reason, int comp_level, bool report) {
 929   print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
 930   if (comp_level == CompLevel_all) {
 931     set_not_c1_osr_compilable();
 932     set_not_c2_osr_compilable();
 933   } else {
 934     if (is_c1_compile(comp_level))
 935       set_not_c1_osr_compilable();
 936     if (is_c2_compile(comp_level))
 937       set_not_c2_osr_compilable();
 938   }
 939   CompilationPolicy::policy()->disable_compilation(this);
 940   assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
 941 }
 942 
 943 // Revert to using the interpreter and clear out the nmethod
 944 void Method::clear_code(bool acquire_lock /* = true */) {
 945   MutexLocker pl(acquire_lock ? Patching_lock : NULL, Mutex::_no_safepoint_check_flag);
 946   // this may be NULL if c2i adapters have not been made yet
 947   // Only should happen at allocate time.
 948   if (adapter() == NULL) {
 949     _from_compiled_entry    = NULL;
 950   } else {
 951     _from_compiled_entry    = adapter()->get_c2i_entry();
 952   }
 953   OrderAccess::storestore();
 954   _from_interpreted_entry = _i2i_entry;
 955   OrderAccess::storestore();
 956   _code = NULL;
 957 }
 958 
 959 #if INCLUDE_CDS
 960 // Called by class data sharing to remove any entry points (which are not shared)
 961 void Method::unlink_method() {
 962   _code = NULL;
 963 
 964   assert(DumpSharedSpaces || DynamicDumpSharedSpaces, "dump time only");
 965   // Set the values to what they should be at run time. Note that
 966   // this Method can no longer be executed during dump time.
 967   _i2i_entry = Interpreter::entry_for_cds_method(this);
 968   _from_interpreted_entry = _i2i_entry;
 969 
 970   if (DynamicDumpSharedSpaces) {
 971     assert(_from_compiled_entry != NULL, "sanity");
 972   } else {
 973     // TODO: Simplify the adapter trampoline allocation for static archiving.
 974     //       Remove the use of CDSAdapterHandlerEntry.
 975     CDSAdapterHandlerEntry* cds_adapter = (CDSAdapterHandlerEntry*)adapter();
 976     constMethod()->set_adapter_trampoline(cds_adapter->get_adapter_trampoline());
 977     _from_compiled_entry = cds_adapter->get_c2i_entry_trampoline();
 978     assert(*((int*)_from_compiled_entry) == 0,
 979            "must be NULL during dump time, to be initialized at run time");
 980   }
 981 
 982   if (is_native()) {
 983     *native_function_addr() = NULL;
 984     set_signature_handler(NULL);
 985   }
 986   NOT_PRODUCT(set_compiled_invocation_count(0);)
 987 
 988   set_method_data(NULL);
 989   clear_method_counters();
 990 }
 991 #endif
 992 
 993 /****************************************************************************
 994 // The following illustrates how the entries work for CDS shared Methods:
 995 //
 996 // Our goal is to delay writing into a shared Method until it's compiled.
 997 // Hence, we want to determine the initial values for _i2i_entry,
 998 // _from_interpreted_entry and _from_compiled_entry during CDS dump time.
 999 //
1000 // In this example, both Methods A and B have the _i2i_entry of "zero_locals".
1001 // They also have similar signatures so that they will share the same
1002 // AdapterHandlerEntry.
1003 //
1004 // _adapter_trampoline points to a fixed location in the RW section of
1005 // the CDS archive. This location initially contains a NULL pointer. When the
1006 // first of method A or B is linked, an AdapterHandlerEntry is allocated
1007 // dynamically, and its c2i/i2c entries are generated.
1008 //
1009 // _i2i_entry and _from_interpreted_entry initially points to the same
1010 // (fixed) location in the CODE section of the CDS archive. This contains
1011 // an unconditional branch to the actual entry for "zero_locals", which is
1012 // generated at run time and may be on an arbitrary address. Thus, the
1013 // unconditional branch is also generated at run time to jump to the correct
1014 // address.
1015 //
1016 // Similarly, _from_compiled_entry points to a fixed address in the CODE
1017 // section. This address has enough space for an unconditional branch
1018 // instruction, and is initially zero-filled. After the AdapterHandlerEntry is
1019 // initialized, and the address for the actual c2i_entry is known, we emit a
1020 // branch instruction here to branch to the actual c2i_entry.
1021 //
1022 // The effect of the extra branch on the i2i and c2i entries is negligible.
1023 //
1024 // The reason for putting _adapter_trampoline in RO is many shared Methods
1025 // share the same AdapterHandlerEntry, so we can save space in the RW section
1026 // by having the extra indirection.
1027 
1028 
1029 [Method A: RW]
1030   _constMethod ----> [ConstMethod: RO]
1031                        _adapter_trampoline -----------+
1032                                                       |
1033   _i2i_entry              (same value as method B)    |
1034   _from_interpreted_entry (same value as method B)    |
1035   _from_compiled_entry    (same value as method B)    |
1036                                                       |
1037                                                       |
1038 [Method B: RW]                               +--------+
1039   _constMethod ----> [ConstMethod: RO]       |
1040                        _adapter_trampoline --+--->(AdapterHandlerEntry* ptr: RW)-+
1041                                                                                  |
1042                                                  +-------------------------------+
1043                                                  |
1044                                                  +----> [AdapterHandlerEntry] (allocated at run time)
1045                                                               _fingerprint
1046                                                               _c2i_entry ---------------------------------+->[c2i entry..]
1047  _i2i_entry  -------------+                                   _i2c_entry ---------------+-> [i2c entry..] |
1048  _from_interpreted_entry  |                                   _c2i_unverified_entry     |                 |
1049          |                |                                   _c2i_no_clinit_check_entry|                 |
1050          |                |  (_cds_entry_table: CODE)                                   |                 |
1051          |                +->[0]: jmp _entry_table[0] --> (i2i_entry_for "zero_locals") |                 |
1052          |                |                               (allocated at run time)       |                 |
1053          |                |  ...                           [asm code ...]               |                 |
1054          +-[not compiled]-+  [n]: jmp _entry_table[n]                                   |                 |
1055          |                                                                              |                 |
1056          |                                                                              |                 |
1057          +-[compiled]-------------------------------------------------------------------+                 |
1058                                                                                                           |
1059  _from_compiled_entry------------>  (_c2i_entry_trampoline: CODE)                                         |
1060                                     [jmp c2i_entry] ------------------------------------------------------+
1061 
1062 ***/
1063 
1064 // Called when the method_holder is getting linked. Setup entrypoints so the method
1065 // is ready to be called from interpreter, compiler, and vtables.
1066 void Method::link_method(const methodHandle& h_method, TRAPS) {
1067   // If the code cache is full, we may reenter this function for the
1068   // leftover methods that weren't linked.
1069   if (is_shared()) {
1070     address entry = Interpreter::entry_for_cds_method(h_method);
1071     assert(entry != NULL && entry == _i2i_entry,
1072            "should be correctly set during dump time");
1073     if (adapter() != NULL) {
1074       return;
1075     }
1076     assert(entry == _from_interpreted_entry,
1077            "should be correctly set during dump time");
1078   } else if (_i2i_entry != NULL) {
1079     return;
1080   }
1081   assert( _code == NULL, "nothing compiled yet" );
1082 
1083   // Setup interpreter entrypoint
1084   assert(this == h_method(), "wrong h_method()" );
1085 
1086   if (!is_shared()) {
1087     assert(adapter() == NULL, "init'd to NULL");
1088     address entry = Interpreter::entry_for_method(h_method);
1089     assert(entry != NULL, "interpreter entry must be non-null");
1090     // Sets both _i2i_entry and _from_interpreted_entry
1091     set_interpreter_entry(entry);
1092   }
1093 
1094   // Don't overwrite already registered native entries.
1095   if (is_native() && !has_native_function()) {
1096     set_native_function(
1097       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1098       !native_bind_event_is_interesting);
1099   }
1100 
1101   // Setup compiler entrypoint.  This is made eagerly, so we do not need
1102   // special handling of vtables.  An alternative is to make adapters more
1103   // lazily by calling make_adapter() from from_compiled_entry() for the
1104   // normal calls.  For vtable calls life gets more complicated.  When a
1105   // call-site goes mega-morphic we need adapters in all methods which can be
1106   // called from the vtable.  We need adapters on such methods that get loaded
1107   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
1108   // problem we'll make these lazily later.
1109   (void) make_adapters(h_method, CHECK);
1110 
1111   set_num_stack_arg_slots();
1112 
1113   // ONLY USE the h_method now as make_adapter may have blocked
1114 
1115 }
1116 
1117 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1118   // Adapters for compiled code are made eagerly here.  They are fairly
1119   // small (generally < 100 bytes) and quick to make (and cached and shared)
1120   // so making them eagerly shouldn't be too expensive.
1121   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1122   if (adapter == NULL ) {
1123     if (!is_init_completed()) {
1124       // Don't throw exceptions during VM initialization because java.lang.* classes
1125       // might not have been initialized, causing problems when constructing the
1126       // Java exception object.
1127       vm_exit_during_initialization("Out of space in CodeCache for adapters");
1128     } else {
1129       THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
1130     }
1131   }
1132 
1133   if (mh->is_shared()) {
1134     assert(mh->adapter() == adapter, "must be");
1135     assert(mh->_from_compiled_entry != NULL, "must be");
1136   } else {
1137     mh->set_adapter_entry(adapter);
1138     mh->_from_compiled_entry = adapter->get_c2i_entry();
1139   }
1140   return adapter->get_c2i_entry();
1141 }
1142 
1143 void Method::restore_unshareable_info(TRAPS) {
1144   assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
1145 
1146   // Since restore_unshareable_info can be called more than once for a method, don't
1147   // redo any work.
1148   if (adapter() == NULL) {
1149     methodHandle mh(THREAD, this);
1150     link_method(mh, CHECK);
1151   }
1152 }
1153 
1154 address Method::from_compiled_entry_no_trampoline() const {
1155   CompiledMethod *code = OrderAccess::load_acquire(&_code);
1156   if (code) {
1157     return code->verified_entry_point();
1158   } else {
1159     return adapter()->get_c2i_entry();
1160   }
1161 }
1162 
1163 // The verified_code_entry() must be called when a invoke is resolved
1164 // on this method.
1165 
1166 // It returns the compiled code entry point, after asserting not null.
1167 // This function is called after potential safepoints so that nmethod
1168 // or adapter that it points to is still live and valid.
1169 // This function must not hit a safepoint!
1170 address Method::verified_code_entry() {
1171   debug_only(NoSafepointVerifier nsv;)
1172   assert(_from_compiled_entry != NULL, "must be set");
1173   return _from_compiled_entry;
1174 }
1175 
1176 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1177 // (could be racing a deopt).
1178 // Not inline to avoid circular ref.
1179 bool Method::check_code() const {
1180   // cached in a register or local.  There's a race on the value of the field.
1181   CompiledMethod *code = OrderAccess::load_acquire(&_code);
1182   return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
1183 }
1184 
1185 // Install compiled code.  Instantly it can execute.
1186 void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
1187   MutexLocker pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1188   assert( code, "use clear_code to remove code" );
1189   assert( mh->check_code(), "" );
1190 
1191   guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
1192 
1193   // These writes must happen in this order, because the interpreter will
1194   // directly jump to from_interpreted_entry which jumps to an i2c adapter
1195   // which jumps to _from_compiled_entry.
1196   mh->_code = code;             // Assign before allowing compiled code to exec
1197 
1198   int comp_level = code->comp_level();
1199   // In theory there could be a race here. In practice it is unlikely
1200   // and not worth worrying about.
1201   if (comp_level > mh->highest_comp_level()) {
1202     mh->set_highest_comp_level(comp_level);
1203   }
1204 
1205   OrderAccess::storestore();
1206   mh->_from_compiled_entry = code->verified_entry_point();
1207   OrderAccess::storestore();
1208   // Instantly compiled code can execute.
1209   if (!mh->is_method_handle_intrinsic())
1210     mh->_from_interpreted_entry = mh->get_i2c_entry();
1211 }
1212 
1213 
1214 bool Method::is_overridden_in(Klass* k) const {
1215   InstanceKlass* ik = InstanceKlass::cast(k);
1216 
1217   if (ik->is_interface()) return false;
1218 
1219   // If method is an interface, we skip it - except if it
1220   // is a miranda method
1221   if (method_holder()->is_interface()) {
1222     // Check that method is not a miranda method
1223     if (ik->lookup_method(name(), signature()) == NULL) {
1224       // No implementation exist - so miranda method
1225       return false;
1226     }
1227     return true;
1228   }
1229 
1230   assert(ik->is_subclass_of(method_holder()), "should be subklass");
1231   if (!has_vtable_index()) {
1232     return false;
1233   } else {
1234     Method* vt_m = ik->method_at_vtable(vtable_index());
1235     return vt_m != this;
1236   }
1237 }
1238 
1239 
1240 // give advice about whether this Method* should be cached or not
1241 bool Method::should_not_be_cached() const {
1242   if (is_old()) {
1243     // This method has been redefined. It is either EMCP or obsolete
1244     // and we don't want to cache it because that would pin the method
1245     // down and prevent it from being collectible if and when it
1246     // finishes executing.
1247     return true;
1248   }
1249 
1250   // caching this method should be just fine
1251   return false;
1252 }
1253 
1254 
1255 /**
1256  *  Returns true if this is one of the specially treated methods for
1257  *  security related stack walks (like Reflection.getCallerClass).
1258  */
1259 bool Method::is_ignored_by_security_stack_walk() const {
1260   if (intrinsic_id() == vmIntrinsics::_invoke) {
1261     // This is Method.invoke() -- ignore it
1262     return true;
1263   }
1264   if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1265     // This is an auxilary frame -- ignore it
1266     return true;
1267   }
1268   if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1269     // This is an internal adapter frame for method handles -- ignore it
1270     return true;
1271   }
1272   return false;
1273 }
1274 
1275 
1276 // Constant pool structure for invoke methods:
1277 enum {
1278   _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.
1279   _imcp_invoke_signature,       // utf8: (variable Symbol*)
1280   _imcp_limit
1281 };
1282 
1283 // Test if this method is an MH adapter frame generated by Java code.
1284 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1285 bool Method::is_compiled_lambda_form() const {
1286   return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1287 }
1288 
1289 // Test if this method is an internal MH primitive method.
1290 bool Method::is_method_handle_intrinsic() const {
1291   vmIntrinsics::ID iid = intrinsic_id();
1292   return (MethodHandles::is_signature_polymorphic(iid) &&
1293           MethodHandles::is_signature_polymorphic_intrinsic(iid));
1294 }
1295 
1296 bool Method::has_member_arg() const {
1297   vmIntrinsics::ID iid = intrinsic_id();
1298   return (MethodHandles::is_signature_polymorphic(iid) &&
1299           MethodHandles::has_member_arg(iid));
1300 }
1301 
1302 // Make an instance of a signature-polymorphic internal MH primitive.
1303 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1304                                                          Symbol* signature,
1305                                                          TRAPS) {
1306   ResourceMark rm;
1307   methodHandle empty;
1308 
1309   InstanceKlass* holder = SystemDictionary::MethodHandle_klass();
1310   Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1311   assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1312   if (TraceMethodHandles) {
1313     tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1314   }
1315 
1316   // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1317   name->increment_refcount();
1318   signature->increment_refcount();
1319 
1320   int cp_length = _imcp_limit;
1321   ClassLoaderData* loader_data = holder->class_loader_data();
1322   constantPoolHandle cp;
1323   {
1324     ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1325     cp = constantPoolHandle(THREAD, cp_oop);
1326   }
1327   cp->set_pool_holder(holder);
1328   cp->symbol_at_put(_imcp_invoke_name,       name);
1329   cp->symbol_at_put(_imcp_invoke_signature,  signature);
1330   cp->set_has_preresolution();
1331 
1332   // decide on access bits:  public or not?
1333   int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1334   bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1335   if (must_be_static)  flags_bits |= JVM_ACC_STATIC;
1336   assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1337 
1338   methodHandle m;
1339   {
1340     InlineTableSizes sizes;
1341     Method* m_oop = Method::allocate(loader_data, 0,
1342                                      accessFlags_from(flags_bits), &sizes,
1343                                      ConstMethod::NORMAL, CHECK_(empty));
1344     m = methodHandle(THREAD, m_oop);
1345   }
1346   m->set_constants(cp());
1347   m->set_name_index(_imcp_invoke_name);
1348   m->set_signature_index(_imcp_invoke_signature);
1349   assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1350   assert(m->signature() == signature, "");
1351   ResultTypeFinder rtf(signature);
1352   m->constMethod()->set_result_type(rtf.type());
1353   m->compute_size_of_parameters(THREAD);
1354   m->init_intrinsic_id();
1355   assert(m->is_method_handle_intrinsic(), "");
1356 #ifdef ASSERT
1357   if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();
1358   assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1359   assert(m->intrinsic_id() == iid, "correctly predicted iid");
1360 #endif //ASSERT
1361 
1362   // Finally, set up its entry points.
1363   assert(m->can_be_statically_bound(), "");
1364   m->set_vtable_index(Method::nonvirtual_vtable_index);
1365   m->link_method(m, CHECK_(empty));
1366 
1367   if (TraceMethodHandles && (Verbose || WizardMode)) {
1368     ttyLocker ttyl;
1369     m->print_on(tty);
1370   }
1371 
1372   return m;
1373 }
1374 
1375 Klass* Method::check_non_bcp_klass(Klass* klass) {
1376   if (klass != NULL && klass->class_loader() != NULL) {
1377     if (klass->is_objArray_klass())
1378       klass = ObjArrayKlass::cast(klass)->bottom_klass();
1379     return klass;
1380   }
1381   return NULL;
1382 }
1383 
1384 
1385 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1386                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1387   // Code below does not work for native methods - they should never get rewritten anyway
1388   assert(!m->is_native(), "cannot rewrite native methods");
1389   // Allocate new Method*
1390   AccessFlags flags = m->access_flags();
1391 
1392   ConstMethod* cm = m->constMethod();
1393   int checked_exceptions_len = cm->checked_exceptions_length();
1394   int localvariable_len = cm->localvariable_table_length();
1395   int exception_table_len = cm->exception_table_length();
1396   int method_parameters_len = cm->method_parameters_length();
1397   int method_annotations_len = cm->method_annotations_length();
1398   int parameter_annotations_len = cm->parameter_annotations_length();
1399   int type_annotations_len = cm->type_annotations_length();
1400   int default_annotations_len = cm->default_annotations_length();
1401 
1402   InlineTableSizes sizes(
1403       localvariable_len,
1404       new_compressed_linenumber_size,
1405       exception_table_len,
1406       checked_exceptions_len,
1407       method_parameters_len,
1408       cm->generic_signature_index(),
1409       method_annotations_len,
1410       parameter_annotations_len,
1411       type_annotations_len,
1412       default_annotations_len,
1413       0);
1414 
1415   ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1416   Method* newm_oop = Method::allocate(loader_data,
1417                                       new_code_length,
1418                                       flags,
1419                                       &sizes,
1420                                       m->method_type(),
1421                                       CHECK_(methodHandle()));
1422   methodHandle newm (THREAD, newm_oop);
1423 
1424   // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1425   ConstMethod* newcm = newm->constMethod();
1426   int new_const_method_size = newm->constMethod()->size();
1427 
1428   // This works because the source and target are both Methods. Some compilers
1429   // (e.g., clang) complain that the target vtable pointer will be stomped,
1430   // so cast away newm()'s and m()'s Methodness.
1431   memcpy((void*)newm(), (void*)m(), sizeof(Method));
1432 
1433   // Create shallow copy of ConstMethod.
1434   memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1435 
1436   // Reset correct method/const method, method size, and parameter info
1437   newm->set_constMethod(newcm);
1438   newm->constMethod()->set_code_size(new_code_length);
1439   newm->constMethod()->set_constMethod_size(new_const_method_size);
1440   assert(newm->code_size() == new_code_length, "check");
1441   assert(newm->method_parameters_length() == method_parameters_len, "check");
1442   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1443   assert(newm->exception_table_length() == exception_table_len, "check");
1444   assert(newm->localvariable_table_length() == localvariable_len, "check");
1445   // Copy new byte codes
1446   memcpy(newm->code_base(), new_code, new_code_length);
1447   // Copy line number table
1448   if (new_compressed_linenumber_size > 0) {
1449     memcpy(newm->compressed_linenumber_table(),
1450            new_compressed_linenumber_table,
1451            new_compressed_linenumber_size);
1452   }
1453   // Copy method_parameters
1454   if (method_parameters_len > 0) {
1455     memcpy(newm->method_parameters_start(),
1456            m->method_parameters_start(),
1457            method_parameters_len * sizeof(MethodParametersElement));
1458   }
1459   // Copy checked_exceptions
1460   if (checked_exceptions_len > 0) {
1461     memcpy(newm->checked_exceptions_start(),
1462            m->checked_exceptions_start(),
1463            checked_exceptions_len * sizeof(CheckedExceptionElement));
1464   }
1465   // Copy exception table
1466   if (exception_table_len > 0) {
1467     memcpy(newm->exception_table_start(),
1468            m->exception_table_start(),
1469            exception_table_len * sizeof(ExceptionTableElement));
1470   }
1471   // Copy local variable number table
1472   if (localvariable_len > 0) {
1473     memcpy(newm->localvariable_table_start(),
1474            m->localvariable_table_start(),
1475            localvariable_len * sizeof(LocalVariableTableElement));
1476   }
1477   // Copy stackmap table
1478   if (m->has_stackmap_table()) {
1479     int code_attribute_length = m->stackmap_data()->length();
1480     Array<u1>* stackmap_data =
1481       MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1482     memcpy((void*)stackmap_data->adr_at(0),
1483            (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1484     newm->set_stackmap_data(stackmap_data);
1485   }
1486 
1487   // copy annotations over to new method
1488   newcm->copy_annotations_from(loader_data, cm, CHECK_NULL);
1489   return newm;
1490 }
1491 
1492 vmSymbols::SID Method::klass_id_for_intrinsics(const Klass* holder) {
1493   // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1494   // because we are not loading from core libraries
1495   // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1496   // which does not use the class default class loader so we check for its loader here
1497   const InstanceKlass* ik = InstanceKlass::cast(holder);
1498   if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1499     return vmSymbols::NO_SID;   // regardless of name, no intrinsics here
1500   }
1501 
1502   // see if the klass name is well-known:
1503   Symbol* klass_name = ik->name();
1504   return vmSymbols::find_sid(klass_name);
1505 }
1506 
1507 void Method::init_intrinsic_id() {
1508   assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1509   const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1510   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1511   assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1512 
1513   // the klass name is well-known:
1514   vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1515   assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1516 
1517   // ditto for method and signature:
1518   vmSymbols::SID  name_id = vmSymbols::find_sid(name());
1519   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1520       && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1521       && name_id == vmSymbols::NO_SID) {
1522     return;
1523   }
1524   vmSymbols::SID   sig_id = vmSymbols::find_sid(signature());
1525   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1526       && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1527       && sig_id == vmSymbols::NO_SID) {
1528     return;
1529   }
1530   jshort flags = access_flags().as_short();
1531 
1532   vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1533   if (id != vmIntrinsics::_none) {
1534     set_intrinsic_id(id);
1535     if (id == vmIntrinsics::_Class_cast) {
1536       // Even if the intrinsic is rejected, we want to inline this simple method.
1537       set_force_inline(true);
1538     }
1539     return;
1540   }
1541 
1542   // A few slightly irregular cases:
1543   switch (klass_id) {
1544   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1545     // Second chance: check in regular Math.
1546     switch (name_id) {
1547     case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1548     case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1549     case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1550       // pretend it is the corresponding method in the non-strict class:
1551       klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1552       id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1553       break;
1554     default:
1555       break;
1556     }
1557     break;
1558 
1559   // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1560   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1561   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1562     if (!is_native())  break;
1563     id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1564     if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1565       id = vmIntrinsics::_none;
1566     break;
1567 
1568   default:
1569     break;
1570   }
1571 
1572   if (id != vmIntrinsics::_none) {
1573     // Set up its iid.  It is an alias method.
1574     set_intrinsic_id(id);
1575     return;
1576   }
1577 }
1578 
1579 // These two methods are static since a GC may move the Method
1580 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1581   if (!THREAD->can_call_java()) {
1582     // There is nothing useful this routine can do from within the Compile thread.
1583     // Hopefully, the signature contains only well-known classes.
1584     // We could scan for this and return true/false, but the caller won't care.
1585     return false;
1586   }
1587   bool sig_is_loaded = true;
1588   Handle class_loader(THREAD, m->method_holder()->class_loader());
1589   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1590   ResourceMark rm(THREAD);
1591   Symbol*  signature = m->signature();
1592   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1593     if (ss.is_object()) {
1594       Symbol* sym = ss.as_symbol();
1595       Symbol*  name  = sym;
1596       Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1597                                              protection_domain, THREAD);
1598       // We are loading classes eagerly. If a ClassNotFoundException or
1599       // a LinkageError was generated, be sure to ignore it.
1600       if (HAS_PENDING_EXCEPTION) {
1601         if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1602             PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1603           CLEAR_PENDING_EXCEPTION;
1604         } else {
1605           return false;
1606         }
1607       }
1608       if( klass == NULL) { sig_is_loaded = false; }
1609     }
1610   }
1611   return sig_is_loaded;
1612 }
1613 
1614 bool Method::has_unloaded_classes_in_signature(const methodHandle& m, TRAPS) {
1615   Handle class_loader(THREAD, m->method_holder()->class_loader());
1616   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1617   ResourceMark rm(THREAD);
1618   Symbol*  signature = m->signature();
1619   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1620     if (ss.type() == T_OBJECT) {
1621       Symbol* name = ss.as_symbol_or_null();
1622       if (name == NULL) return true;
1623       Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1624       if (klass == NULL) return true;
1625     }
1626   }
1627   return false;
1628 }
1629 
1630 // Exposed so field engineers can debug VM
1631 void Method::print_short_name(outputStream* st) const {
1632   ResourceMark rm;
1633 #ifdef PRODUCT
1634   st->print(" %s::", method_holder()->external_name());
1635 #else
1636   st->print(" %s::", method_holder()->internal_name());
1637 #endif
1638   name()->print_symbol_on(st);
1639   if (WizardMode) signature()->print_symbol_on(st);
1640   else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1641     MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1642 }
1643 
1644 // Comparer for sorting an object array containing
1645 // Method*s.
1646 static int method_comparator(Method* a, Method* b) {
1647   return a->name()->fast_compare(b->name());
1648 }
1649 
1650 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1651 // default_methods also uses this without the ordering for fast find_method
1652 void Method::sort_methods(Array<Method*>* methods, bool set_idnums) {
1653   int length = methods->length();
1654   if (length > 1) {
1655     {
1656       NoSafepointVerifier nsv;
1657       QuickSort::sort(methods->data(), length, method_comparator, /*idempotent=*/false);
1658     }
1659     // Reset method ordering
1660     if (set_idnums) {
1661       for (int i = 0; i < length; i++) {
1662         Method* m = methods->at(i);
1663         m->set_method_idnum(i);
1664         m->set_orig_method_idnum(i);
1665       }
1666     }
1667   }
1668 }
1669 
1670 void Method::set_num_stack_arg_slots() {
1671   ResourceMark rm;
1672   int sizeargs = size_of_parameters();
1673   BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
1674   VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
1675 
1676   int sig_index = 0;
1677   if (!is_static()) sig_bt[sig_index++] = T_OBJECT; // 'this'
1678   for (SignatureStream ss(signature()); !ss.at_return_type(); ss.next()) {
1679     BasicType t = ss.type();
1680     assert(type2size[t] == 1 || type2size[t] == 2, "size is 1 or 2");
1681     sig_bt[sig_index++] = t;
1682     if (type2size[t] == 2) sig_bt[sig_index++] = T_VOID;
1683   }
1684   assert(sig_index == sizeargs, "");
1685 
1686   _num_stack_arg_slots = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
1687 }
1688 
1689 //-----------------------------------------------------------------------------------
1690 // Non-product code unless JVM/TI needs it
1691 
1692 #if !defined(PRODUCT) || INCLUDE_JVMTI
1693 class SignatureTypePrinter : public SignatureTypeNames {
1694  private:
1695   outputStream* _st;
1696   bool _use_separator;
1697 
1698   void type_name(const char* name) {
1699     if (_use_separator) _st->print(", ");
1700     _st->print("%s", name);
1701     _use_separator = true;
1702   }
1703 
1704  public:
1705   SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1706     _st = st;
1707     _use_separator = false;
1708   }
1709 
1710   void print_parameters()              { _use_separator = false; iterate_parameters(); }
1711   void print_returntype()              { _use_separator = false; iterate_returntype(); }
1712 };
1713 
1714 
1715 void Method::print_name(outputStream* st) const {
1716   Thread *thread = Thread::current();
1717   ResourceMark rm(thread);
1718   st->print("%s ", is_static() ? "static" : "virtual");
1719   if (WizardMode) {
1720     st->print("%s.", method_holder()->internal_name());
1721     name()->print_symbol_on(st);
1722     signature()->print_symbol_on(st);
1723   } else {
1724     SignatureTypePrinter sig(signature(), st);
1725     sig.print_returntype();
1726     st->print(" %s.", method_holder()->internal_name());
1727     name()->print_symbol_on(st);
1728     st->print("(");
1729     sig.print_parameters();
1730     st->print(")");
1731   }
1732 }
1733 #endif // !PRODUCT || INCLUDE_JVMTI
1734 
1735 
1736 void Method::print_codes_on(outputStream* st) const {
1737   print_codes_on(0, code_size(), st);
1738 }
1739 
1740 void Method::print_codes_on(int from, int to, outputStream* st) const {
1741   Thread *thread = Thread::current();
1742   ResourceMark rm(thread);
1743   methodHandle mh (thread, (Method*)this);
1744   BytecodeStream s(mh);
1745   s.set_interval(from, to);
1746   BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1747   while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1748 }
1749 
1750 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1751   _bci = 0;
1752   _line = 0;
1753 };
1754 
1755 bool CompressedLineNumberReadStream::read_pair() {
1756   jubyte next = read_byte();
1757   // Check for terminator
1758   if (next == 0) return false;
1759   if (next == 0xFF) {
1760     // Escape character, regular compression used
1761     _bci  += read_signed_int();
1762     _line += read_signed_int();
1763   } else {
1764     // Single byte compression used
1765     _bci  += next >> 3;
1766     _line += next & 0x7;
1767   }
1768   return true;
1769 }
1770 
1771 #if INCLUDE_JVMTI
1772 
1773 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1774   BreakpointInfo* bp = method_holder()->breakpoints();
1775   for (; bp != NULL; bp = bp->next()) {
1776     if (bp->match(this, bci)) {
1777       return bp->orig_bytecode();
1778     }
1779   }
1780   {
1781     ResourceMark rm;
1782     fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1783   }
1784   return Bytecodes::_shouldnotreachhere;
1785 }
1786 
1787 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1788   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1789   BreakpointInfo* bp = method_holder()->breakpoints();
1790   for (; bp != NULL; bp = bp->next()) {
1791     if (bp->match(this, bci)) {
1792       bp->set_orig_bytecode(code);
1793       // and continue, in case there is more than one
1794     }
1795   }
1796 }
1797 
1798 void Method::set_breakpoint(int bci) {
1799   InstanceKlass* ik = method_holder();
1800   BreakpointInfo *bp = new BreakpointInfo(this, bci);
1801   bp->set_next(ik->breakpoints());
1802   ik->set_breakpoints(bp);
1803   // do this last:
1804   bp->set(this);
1805 }
1806 
1807 static void clear_matches(Method* m, int bci) {
1808   InstanceKlass* ik = m->method_holder();
1809   BreakpointInfo* prev_bp = NULL;
1810   BreakpointInfo* next_bp;
1811   for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1812     next_bp = bp->next();
1813     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1814     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1815       // do this first:
1816       bp->clear(m);
1817       // unhook it
1818       if (prev_bp != NULL)
1819         prev_bp->set_next(next_bp);
1820       else
1821         ik->set_breakpoints(next_bp);
1822       delete bp;
1823       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1824       // at same location. So we have multiple matching (method_index and bci)
1825       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1826       // breakpoint for clear_breakpoint request and keep all other method versions
1827       // BreakpointInfo for future clear_breakpoint request.
1828       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1829       // which is being called when class is unloaded. We delete all the Breakpoint
1830       // information for all versions of method. We may not correctly restore the original
1831       // bytecode in all method versions, but that is ok. Because the class is being unloaded
1832       // so these methods won't be used anymore.
1833       if (bci >= 0) {
1834         break;
1835       }
1836     } else {
1837       // This one is a keeper.
1838       prev_bp = bp;
1839     }
1840   }
1841 }
1842 
1843 void Method::clear_breakpoint(int bci) {
1844   assert(bci >= 0, "");
1845   clear_matches(this, bci);
1846 }
1847 
1848 void Method::clear_all_breakpoints() {
1849   clear_matches(this, -1);
1850 }
1851 
1852 #endif // INCLUDE_JVMTI
1853 
1854 int Method::invocation_count() {
1855   MethodCounters *mcs = method_counters();
1856   if (TieredCompilation) {
1857     MethodData* const mdo = method_data();
1858     if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1859         ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1860       return InvocationCounter::count_limit;
1861     } else {
1862       return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1863              ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1864     }
1865   } else {
1866     return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1867   }
1868 }
1869 
1870 int Method::backedge_count() {
1871   MethodCounters *mcs = method_counters();
1872   if (TieredCompilation) {
1873     MethodData* const mdo = method_data();
1874     if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1875         ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1876       return InvocationCounter::count_limit;
1877     } else {
1878       return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1879              ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1880     }
1881   } else {
1882     return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1883   }
1884 }
1885 
1886 int Method::highest_comp_level() const {
1887   const MethodCounters* mcs = method_counters();
1888   if (mcs != NULL) {
1889     return mcs->highest_comp_level();
1890   } else {
1891     return CompLevel_none;
1892   }
1893 }
1894 
1895 int Method::highest_osr_comp_level() const {
1896   const MethodCounters* mcs = method_counters();
1897   if (mcs != NULL) {
1898     return mcs->highest_osr_comp_level();
1899   } else {
1900     return CompLevel_none;
1901   }
1902 }
1903 
1904 void Method::set_highest_comp_level(int level) {
1905   MethodCounters* mcs = method_counters();
1906   if (mcs != NULL) {
1907     mcs->set_highest_comp_level(level);
1908   }
1909 }
1910 
1911 void Method::set_highest_osr_comp_level(int level) {
1912   MethodCounters* mcs = method_counters();
1913   if (mcs != NULL) {
1914     mcs->set_highest_osr_comp_level(level);
1915   }
1916 }
1917 
1918 #if INCLUDE_JVMTI
1919 
1920 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1921   _bci = bci;
1922   _name_index = m->name_index();
1923   _signature_index = m->signature_index();
1924   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1925   if (_orig_bytecode == Bytecodes::_breakpoint)
1926     _orig_bytecode = m->orig_bytecode_at(_bci);
1927   _next = NULL;
1928 }
1929 
1930 void BreakpointInfo::set(Method* method) {
1931 #ifdef ASSERT
1932   {
1933     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
1934     if (code == Bytecodes::_breakpoint)
1935       code = method->orig_bytecode_at(_bci);
1936     assert(orig_bytecode() == code, "original bytecode must be the same");
1937   }
1938 #endif
1939   Thread *thread = Thread::current();
1940   *method->bcp_from(_bci) = Bytecodes::_breakpoint;
1941   method->incr_number_of_breakpoints(thread);
1942   {
1943     // Deoptimize all dependents on this method
1944     HandleMark hm(thread);
1945     methodHandle mh(thread, method);
1946     CodeCache::flush_dependents_on_method(mh);
1947   }
1948 }
1949 
1950 void BreakpointInfo::clear(Method* method) {
1951   *method->bcp_from(_bci) = orig_bytecode();
1952   assert(method->number_of_breakpoints() > 0, "must not go negative");
1953   method->decr_number_of_breakpoints(Thread::current());
1954 }
1955 
1956 #endif // INCLUDE_JVMTI
1957 
1958 // jmethodID handling
1959 
1960 // This is a block allocating object, sort of like JNIHandleBlock, only a
1961 // lot simpler.
1962 // It's allocated on the CHeap because once we allocate a jmethodID, we can
1963 // never get rid of it.
1964 
1965 static const int min_block_size = 8;
1966 
1967 class JNIMethodBlockNode : public CHeapObj<mtClass> {
1968   friend class JNIMethodBlock;
1969   Method**        _methods;
1970   int             _number_of_methods;
1971   int             _top;
1972   JNIMethodBlockNode* _next;
1973 
1974  public:
1975 
1976   JNIMethodBlockNode(int num_methods = min_block_size);
1977 
1978   ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
1979 
1980   void ensure_methods(int num_addl_methods) {
1981     if (_top < _number_of_methods) {
1982       num_addl_methods -= _number_of_methods - _top;
1983       if (num_addl_methods <= 0) {
1984         return;
1985       }
1986     }
1987     if (_next == NULL) {
1988       _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
1989     } else {
1990       _next->ensure_methods(num_addl_methods);
1991     }
1992   }
1993 };
1994 
1995 class JNIMethodBlock : public CHeapObj<mtClass> {
1996   JNIMethodBlockNode _head;
1997   JNIMethodBlockNode *_last_free;
1998  public:
1999   static Method* const _free_method;
2000 
2001   JNIMethodBlock(int initial_capacity = min_block_size)
2002       : _head(initial_capacity), _last_free(&_head) {}
2003 
2004   void ensure_methods(int num_addl_methods) {
2005     _last_free->ensure_methods(num_addl_methods);
2006   }
2007 
2008   Method** add_method(Method* m) {
2009     for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
2010       if (b->_top < b->_number_of_methods) {
2011         // top points to the next free entry.
2012         int i = b->_top;
2013         b->_methods[i] = m;
2014         b->_top++;
2015         _last_free = b;
2016         return &(b->_methods[i]);
2017       } else if (b->_top == b->_number_of_methods) {
2018         // if the next free entry ran off the block see if there's a free entry
2019         for (int i = 0; i < b->_number_of_methods; i++) {
2020           if (b->_methods[i] == _free_method) {
2021             b->_methods[i] = m;
2022             _last_free = b;
2023             return &(b->_methods[i]);
2024           }
2025         }
2026         // Only check each block once for frees.  They're very unlikely.
2027         // Increment top past the end of the block.
2028         b->_top++;
2029       }
2030       // need to allocate a next block.
2031       if (b->_next == NULL) {
2032         b->_next = _last_free = new JNIMethodBlockNode();
2033       }
2034     }
2035     guarantee(false, "Should always allocate a free block");
2036     return NULL;
2037   }
2038 
2039   bool contains(Method** m) {
2040     if (m == NULL) return false;
2041     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2042       if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2043         // This is a bit of extra checking, for two reasons.  One is
2044         // that contains() deals with pointers that are passed in by
2045         // JNI code, so making sure that the pointer is aligned
2046         // correctly is valuable.  The other is that <= and > are
2047         // technically not defined on pointers, so the if guard can
2048         // pass spuriously; no modern compiler is likely to make that
2049         // a problem, though (and if one did, the guard could also
2050         // fail spuriously, which would be bad).
2051         ptrdiff_t idx = m - b->_methods;
2052         if (b->_methods + idx == m) {
2053           return true;
2054         }
2055       }
2056     }
2057     return false;  // not found
2058   }
2059 
2060   // Doesn't really destroy it, just marks it as free so it can be reused.
2061   void destroy_method(Method** m) {
2062 #ifdef ASSERT
2063     assert(contains(m), "should be a methodID");
2064 #endif // ASSERT
2065     *m = _free_method;
2066   }
2067 
2068   // During class unloading the methods are cleared, which is different
2069   // than freed.
2070   void clear_all_methods() {
2071     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2072       for (int i = 0; i< b->_number_of_methods; i++) {
2073         b->_methods[i] = NULL;
2074       }
2075     }
2076   }
2077 #ifndef PRODUCT
2078   int count_methods() {
2079     // count all allocated methods
2080     int count = 0;
2081     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2082       for (int i = 0; i< b->_number_of_methods; i++) {
2083         if (b->_methods[i] != _free_method) count++;
2084       }
2085     }
2086     return count;
2087   }
2088 #endif // PRODUCT
2089 };
2090 
2091 // Something that can't be mistaken for an address or a markOop
2092 Method* const JNIMethodBlock::_free_method = (Method*)55;
2093 
2094 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(NULL) {
2095   _number_of_methods = MAX2(num_methods, min_block_size);
2096   _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2097   for (int i = 0; i < _number_of_methods; i++) {
2098     _methods[i] = JNIMethodBlock::_free_method;
2099   }
2100 }
2101 
2102 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
2103   ClassLoaderData* cld = loader_data;
2104   if (!SafepointSynchronize::is_at_safepoint()) {
2105     // Have to add jmethod_ids() to class loader data thread-safely.
2106     // Also have to add the method to the list safely, which the cld lock
2107     // protects as well.
2108     MutexLocker ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
2109     if (cld->jmethod_ids() == NULL) {
2110       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2111     } else {
2112       cld->jmethod_ids()->ensure_methods(capacity);
2113     }
2114   } else {
2115     // At safepoint, we are single threaded and can set this.
2116     if (cld->jmethod_ids() == NULL) {
2117       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2118     } else {
2119       cld->jmethod_ids()->ensure_methods(capacity);
2120     }
2121   }
2122 }
2123 
2124 // Add a method id to the jmethod_ids
2125 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
2126   ClassLoaderData* cld = loader_data;
2127 
2128   if (!SafepointSynchronize::is_at_safepoint()) {
2129     // Have to add jmethod_ids() to class loader data thread-safely.
2130     // Also have to add the method to the list safely, which the cld lock
2131     // protects as well.
2132     MutexLocker ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
2133     if (cld->jmethod_ids() == NULL) {
2134       cld->set_jmethod_ids(new JNIMethodBlock());
2135     }
2136     // jmethodID is a pointer to Method*
2137     return (jmethodID)cld->jmethod_ids()->add_method(m);
2138   } else {
2139     // At safepoint, we are single threaded and can set this.
2140     if (cld->jmethod_ids() == NULL) {
2141       cld->set_jmethod_ids(new JNIMethodBlock());
2142     }
2143     // jmethodID is a pointer to Method*
2144     return (jmethodID)cld->jmethod_ids()->add_method(m);
2145   }
2146 }
2147 
2148 // Mark a jmethodID as free.  This is called when there is a data race in
2149 // InstanceKlass while creating the jmethodID cache.
2150 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
2151   ClassLoaderData* cld = loader_data;
2152   Method** ptr = (Method**)m;
2153   assert(cld->jmethod_ids() != NULL, "should have method handles");
2154   cld->jmethod_ids()->destroy_method(ptr);
2155 }
2156 
2157 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2158   // Can't assert the method_holder is the same because the new method has the
2159   // scratch method holder.
2160   assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2161            == new_method->method_holder()->class_loader() ||
2162            new_method->method_holder()->class_loader() == NULL, // allow Unsafe substitution
2163          "changing to a different class loader");
2164   // Just change the method in place, jmethodID pointer doesn't change.
2165   *((Method**)jmid) = new_method;
2166 }
2167 
2168 bool Method::is_method_id(jmethodID mid) {
2169   Method* m = resolve_jmethod_id(mid);
2170   assert(m != NULL, "should be called with non-null method");
2171   InstanceKlass* ik = m->method_holder();
2172   ClassLoaderData* cld = ik->class_loader_data();
2173   if (cld->jmethod_ids() == NULL) return false;
2174   return (cld->jmethod_ids()->contains((Method**)mid));
2175 }
2176 
2177 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2178   if (mid == NULL) return NULL;
2179   Method* o = resolve_jmethod_id(mid);
2180   if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
2181     return NULL;
2182   }
2183   return o;
2184 };
2185 
2186 void Method::set_on_stack(const bool value) {
2187   // Set both the method itself and its constant pool.  The constant pool
2188   // on stack means some method referring to it is also on the stack.
2189   constants()->set_on_stack(value);
2190 
2191   bool already_set = on_stack();
2192   _access_flags.set_on_stack(value);
2193   if (value && !already_set) {
2194     MetadataOnStackMark::record(this);
2195   }
2196   assert(!value || !is_old() || is_obsolete() || is_running_emcp(),
2197          "emcp methods cannot run after emcp bit is cleared");
2198 }
2199 
2200 // Called when the class loader is unloaded to make all methods weak.
2201 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2202   loader_data->jmethod_ids()->clear_all_methods();
2203 }
2204 
2205 bool Method::has_method_vptr(const void* ptr) {
2206   Method m;
2207   // This assumes that the vtbl pointer is the first word of a C++ object.
2208   return dereference_vptr(&m) == dereference_vptr(ptr);
2209 }
2210 
2211 // Check that this pointer is valid by checking that the vtbl pointer matches
2212 bool Method::is_valid_method(const Method* m) {
2213   if (m == NULL) {
2214     return false;
2215   } else if ((intptr_t(m) & (wordSize-1)) != 0) {
2216     // Quick sanity check on pointer.
2217     return false;
2218   } else if (m->is_shared()) {
2219     return MetaspaceShared::is_valid_shared_method(m);
2220   } else if (Metaspace::contains_non_shared(m)) {
2221     return has_method_vptr((const void*)m);
2222   } else {
2223     return false;
2224   }
2225 }
2226 
2227 #ifndef PRODUCT
2228 void Method::print_jmethod_ids(const ClassLoaderData* loader_data, outputStream* out) {
2229   out->print(" jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2230 }
2231 #endif // PRODUCT
2232 
2233 
2234 // Printing
2235 
2236 #ifndef PRODUCT
2237 
2238 void Method::print_on(outputStream* st) const {
2239   ResourceMark rm;
2240   assert(is_method(), "must be method");
2241   st->print_cr("%s", internal_name());
2242   st->print_cr(" - this oop:          " INTPTR_FORMAT, p2i(this));
2243   st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();
2244   st->print   (" - constants:         " INTPTR_FORMAT " ", p2i(constants()));
2245   constants()->print_value_on(st); st->cr();
2246   st->print   (" - access:            0x%x  ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2247   st->print   (" - name:              ");    name()->print_value_on(st); st->cr();
2248   st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();
2249   st->print_cr(" - max stack:         %d",   max_stack());
2250   st->print_cr(" - max locals:        %d",   max_locals());
2251   st->print_cr(" - size of params:    %d",   size_of_parameters());
2252   st->print_cr(" - method size:       %d",   method_size());
2253   if (intrinsic_id() != vmIntrinsics::_none)
2254     st->print_cr(" - intrinsic id:      %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
2255   if (highest_comp_level() != CompLevel_none)
2256     st->print_cr(" - highest level:     %d", highest_comp_level());
2257   st->print_cr(" - vtable index:      %d",   _vtable_index);
2258   st->print_cr(" - i2i entry:         " INTPTR_FORMAT, p2i(interpreter_entry()));
2259   st->print(   " - adapters:          ");
2260   AdapterHandlerEntry* a = ((Method*)this)->adapter();
2261   if (a == NULL)
2262     st->print_cr(INTPTR_FORMAT, p2i(a));
2263   else
2264     a->print_adapter_on(st);
2265   st->print_cr(" - compiled entry     " INTPTR_FORMAT, p2i(from_compiled_entry()));
2266   st->print_cr(" - code size:         %d",   code_size());
2267   if (code_size() != 0) {
2268     st->print_cr(" - code start:        " INTPTR_FORMAT, p2i(code_base()));
2269     st->print_cr(" - code end (excl):   " INTPTR_FORMAT, p2i(code_base() + code_size()));
2270   }
2271   if (method_data() != NULL) {
2272     st->print_cr(" - method data:       " INTPTR_FORMAT, p2i(method_data()));
2273   }
2274   st->print_cr(" - checked ex length: %d",   checked_exceptions_length());
2275   if (checked_exceptions_length() > 0) {
2276     CheckedExceptionElement* table = checked_exceptions_start();
2277     st->print_cr(" - checked ex start:  " INTPTR_FORMAT, p2i(table));
2278     if (Verbose) {
2279       for (int i = 0; i < checked_exceptions_length(); i++) {
2280         st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2281       }
2282     }
2283   }
2284   if (has_linenumber_table()) {
2285     u_char* table = compressed_linenumber_table();
2286     st->print_cr(" - linenumber start:  " INTPTR_FORMAT, p2i(table));
2287     if (Verbose) {
2288       CompressedLineNumberReadStream stream(table);
2289       while (stream.read_pair()) {
2290         st->print_cr("   - line %d: %d", stream.line(), stream.bci());
2291       }
2292     }
2293   }
2294   st->print_cr(" - localvar length:   %d",   localvariable_table_length());
2295   if (localvariable_table_length() > 0) {
2296     LocalVariableTableElement* table = localvariable_table_start();
2297     st->print_cr(" - localvar start:    " INTPTR_FORMAT, p2i(table));
2298     if (Verbose) {
2299       for (int i = 0; i < localvariable_table_length(); i++) {
2300         int bci = table[i].start_bci;
2301         int len = table[i].length;
2302         const char* name = constants()->printable_name_at(table[i].name_cp_index);
2303         const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2304         int slot = table[i].slot;
2305         st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2306       }
2307     }
2308   }
2309   if (code() != NULL) {
2310     st->print   (" - compiled code: ");
2311     code()->print_value_on(st);
2312   }
2313   if (is_native()) {
2314     st->print_cr(" - native function:   " INTPTR_FORMAT, p2i(native_function()));
2315     st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2316   }
2317 }
2318 
2319 void Method::print_linkage_flags(outputStream* st) {
2320   access_flags().print_on(st);
2321   if (is_default_method()) {
2322     st->print("default ");
2323   }
2324   if (is_overpass()) {
2325     st->print("overpass ");
2326   }
2327 }
2328 #endif //PRODUCT
2329 
2330 void Method::print_value_on(outputStream* st) const {
2331   assert(is_method(), "must be method");
2332   st->print("%s", internal_name());
2333   print_address_on(st);
2334   st->print(" ");
2335   name()->print_value_on(st);
2336   st->print(" ");
2337   signature()->print_value_on(st);
2338   st->print(" in ");
2339   method_holder()->print_value_on(st);
2340   if (WizardMode) st->print("#%d", _vtable_index);
2341   if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2342   if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2343 }
2344 
2345 #if INCLUDE_SERVICES
2346 // Size Statistics
2347 void Method::collect_statistics(KlassSizeStats *sz) const {
2348   int mysize = sz->count(this);
2349   sz->_method_bytes += mysize;
2350   sz->_method_all_bytes += mysize;
2351   sz->_rw_bytes += mysize;
2352 
2353   if (constMethod()) {
2354     constMethod()->collect_statistics(sz);
2355   }
2356   if (method_data()) {
2357     method_data()->collect_statistics(sz);
2358   }
2359 }
2360 #endif // INCLUDE_SERVICES
2361 
2362 // LogTouchedMethods and PrintTouchedMethods
2363 
2364 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2365 // the Method may be garbage collected. Let's roll our own hash table.
2366 class TouchedMethodRecord : CHeapObj<mtTracing> {
2367 public:
2368   // It's OK to store Symbols here because they will NOT be GC'ed if
2369   // LogTouchedMethods is enabled.
2370   TouchedMethodRecord* _next;
2371   Symbol* _class_name;
2372   Symbol* _method_name;
2373   Symbol* _method_signature;
2374 };
2375 
2376 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2377 static TouchedMethodRecord** _touched_method_table = NULL;
2378 
2379 void Method::log_touched(TRAPS) {
2380 
2381   const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2382   Symbol* my_class = klass_name();
2383   Symbol* my_name  = name();
2384   Symbol* my_sig   = signature();
2385 
2386   unsigned int hash = my_class->identity_hash() +
2387                       my_name->identity_hash() +
2388                       my_sig->identity_hash();
2389   juint index = juint(hash) % table_size;
2390 
2391   MutexLocker ml(TouchedMethodLog_lock, THREAD);
2392   if (_touched_method_table == NULL) {
2393     _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2394                                               mtTracing, CURRENT_PC);
2395     memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2396   }
2397 
2398   TouchedMethodRecord* ptr = _touched_method_table[index];
2399   while (ptr) {
2400     if (ptr->_class_name       == my_class &&
2401         ptr->_method_name      == my_name &&
2402         ptr->_method_signature == my_sig) {
2403       return;
2404     }
2405     if (ptr->_next == NULL) break;
2406     ptr = ptr->_next;
2407   }
2408   TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2409   my_class->increment_refcount();
2410   my_name->increment_refcount();
2411   my_sig->increment_refcount();
2412   nptr->_class_name         = my_class;
2413   nptr->_method_name        = my_name;
2414   nptr->_method_signature   = my_sig;
2415   nptr->_next               = NULL;
2416 
2417   if (ptr == NULL) {
2418     // first
2419     _touched_method_table[index] = nptr;
2420   } else {
2421     ptr->_next = nptr;
2422   }
2423 }
2424 
2425 void Method::print_touched_methods(outputStream* out) {
2426   MutexLocker ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2427   out->print_cr("# Method::print_touched_methods version 1");
2428   if (_touched_method_table) {
2429     for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2430       TouchedMethodRecord* ptr = _touched_method_table[i];
2431       while(ptr) {
2432         ptr->_class_name->print_symbol_on(out);       out->print(".");
2433         ptr->_method_name->print_symbol_on(out);      out->print(":");
2434         ptr->_method_signature->print_symbol_on(out); out->cr();
2435         ptr = ptr->_next;
2436       }
2437     }
2438   }
2439 }
2440 
2441 // Verification
2442 
2443 void Method::verify_on(outputStream* st) {
2444   guarantee(is_method(), "object must be method");
2445   guarantee(constants()->is_constantPool(), "should be constant pool");
2446   MethodData* md = method_data();
2447   guarantee(md == NULL ||
2448       md->is_methodData(), "should be method data");
2449 }