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   Method::clear_code(); // 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 Symbol* Method::klass_name() const {
 328   return method_holder()->name();
 329 }
 330 
 331 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
 332   log_trace(cds)("Iter(Method): %p", this);
 333 
 334   it->push(&_constMethod);
 335   it->push(&_method_data);
 336   it->push(&_method_counters);
 337 
 338   Method* this_ptr = this;
 339   it->push_method_entry(&this_ptr, (intptr_t*)&_i2i_entry);
 340   it->push_method_entry(&this_ptr, (intptr_t*)&_from_compiled_entry);
 341   it->push_method_entry(&this_ptr, (intptr_t*)&_from_interpreted_entry);
 342 }
 343 
 344 // Attempt to return method oop to original state.  Clear any pointers
 345 // (to objects outside the shared spaces).  We won't be able to predict
 346 // where they should point in a new JVM.  Further initialize some
 347 // entries now in order allow them to be write protected later.
 348 
 349 void Method::remove_unshareable_info() {
 350   unlink_method();
 351 }
 352 
 353 void Method::set_vtable_index(int index) {
 354   if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
 355     // At runtime initialize_vtable is rerun as part of link_class_impl()
 356     // for a shared class loaded by the non-boot loader to obtain the loader
 357     // constraints based on the runtime classloaders' context.
 358     return; // don't write into the shared class
 359   } else {
 360     _vtable_index = index;
 361   }
 362 }
 363 
 364 void Method::set_itable_index(int index) {
 365   if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
 366     // At runtime initialize_itable is rerun as part of link_class_impl()
 367     // for a shared class loaded by the non-boot loader to obtain the loader
 368     // constraints based on the runtime classloaders' context. The dumptime
 369     // itable index should be the same as the runtime index.
 370     assert(_vtable_index == itable_index_max - index,
 371            "archived itable index is different from runtime index");
 372     return; // don’t write into the shared class
 373   } else {
 374     _vtable_index = itable_index_max - index;
 375   }
 376   assert(valid_itable_index(), "");
 377 }
 378 
 379 
 380 
 381 bool Method::was_executed_more_than(int n) {
 382   // Invocation counter is reset when the Method* is compiled.
 383   // If the method has compiled code we therefore assume it has
 384   // be excuted more than n times.
 385   if (is_accessor() || is_empty_method() || (code() != NULL)) {
 386     // interpreter doesn't bump invocation counter of trivial methods
 387     // compiler does not bump invocation counter of compiled methods
 388     return true;
 389   }
 390   else if ((method_counters() != NULL &&
 391             method_counters()->invocation_counter()->carry()) ||
 392            (method_data() != NULL &&
 393             method_data()->invocation_counter()->carry())) {
 394     // The carry bit is set when the counter overflows and causes
 395     // a compilation to occur.  We don't know how many times
 396     // the counter has been reset, so we simply assume it has
 397     // been executed more than n times.
 398     return true;
 399   } else {
 400     return invocation_count() > n;
 401   }
 402 }
 403 
 404 void Method::print_invocation_count() {
 405   if (is_static()) tty->print("static ");
 406   if (is_final()) tty->print("final ");
 407   if (is_synchronized()) tty->print("synchronized ");
 408   if (is_native()) tty->print("native ");
 409   tty->print("%s::", method_holder()->external_name());
 410   name()->print_symbol_on(tty);
 411   signature()->print_symbol_on(tty);
 412 
 413   if (WizardMode) {
 414     // dump the size of the byte codes
 415     tty->print(" {%d}", code_size());
 416   }
 417   tty->cr();
 418 
 419   tty->print_cr ("  interpreter_invocation_count: %8d ", interpreter_invocation_count());
 420   tty->print_cr ("  invocation_counter:           %8d ", invocation_count());
 421   tty->print_cr ("  backedge_counter:             %8d ", backedge_count());
 422 #ifndef PRODUCT
 423   if (CountCompiledCalls) {
 424     tty->print_cr ("  compiled_invocation_count: %8d ", compiled_invocation_count());
 425   }
 426 #endif
 427 }
 428 
 429 // Build a MethodData* object to hold information about this method
 430 // collected in the interpreter.
 431 void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) {
 432   // Do not profile the method if metaspace has hit an OOM previously
 433   // allocating profiling data. Callers clear pending exception so don't
 434   // add one here.
 435   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 436     return;
 437   }
 438 
 439   // Grab a lock here to prevent multiple
 440   // MethodData*s from being created.
 441   MutexLocker ml(MethodData_lock, THREAD);
 442   if (method->method_data() == NULL) {
 443     ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
 444     MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
 445     if (HAS_PENDING_EXCEPTION) {
 446       CompileBroker::log_metaspace_failure();
 447       ClassLoaderDataGraph::set_metaspace_oom(true);
 448       return;   // return the exception (which is cleared)
 449     }
 450 
 451     method->set_method_data(method_data);
 452     if (PrintMethodData && (Verbose || WizardMode)) {
 453       ResourceMark rm(THREAD);
 454       tty->print("build_interpreter_method_data for ");
 455       method->print_name(tty);
 456       tty->cr();
 457       // At the end of the run, the MDO, full of data, will be dumped.
 458     }
 459   }
 460 }
 461 
 462 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
 463   // Do not profile the method if metaspace has hit an OOM previously
 464   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 465     return NULL;
 466   }
 467 
 468   methodHandle mh(m);
 469   MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
 470   if (HAS_PENDING_EXCEPTION) {
 471     CompileBroker::log_metaspace_failure();
 472     ClassLoaderDataGraph::set_metaspace_oom(true);
 473     return NULL;   // return the exception (which is cleared)
 474   }
 475   if (!mh->init_method_counters(counters)) {
 476     MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
 477   }
 478 
 479   if (LogTouchedMethods) {
 480     mh->log_touched(CHECK_NULL);
 481   }
 482 
 483   return mh->method_counters();
 484 }
 485 
 486 bool Method::init_method_counters(MethodCounters* counters) {
 487   // Try to install a pointer to MethodCounters, return true on success.
 488   return Atomic::replace_if_null(counters, &_method_counters);
 489 }
 490 
 491 int Method::extra_stack_words() {
 492   // not an inline function, to avoid a header dependency on Interpreter
 493   return extra_stack_entries() * Interpreter::stackElementSize;
 494 }
 495 
 496 
 497 void Method::compute_size_of_parameters(Thread *thread) {
 498   ArgumentSizeComputer asc(signature());
 499   set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
 500 }
 501 
 502 BasicType Method::result_type() const {
 503   ResultTypeFinder rtf(signature());
 504   return rtf.type();
 505 }
 506 
 507 
 508 bool Method::is_empty_method() const {
 509   return  code_size() == 1
 510       && *code_base() == Bytecodes::_return;
 511 }
 512 
 513 
 514 bool Method::is_vanilla_constructor() const {
 515   // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
 516   // which only calls the superclass vanilla constructor and possibly does stores of
 517   // zero constants to local fields:
 518   //
 519   //   aload_0
 520   //   invokespecial
 521   //   indexbyte1
 522   //   indexbyte2
 523   //
 524   // followed by an (optional) sequence of:
 525   //
 526   //   aload_0
 527   //   aconst_null / iconst_0 / fconst_0 / dconst_0
 528   //   putfield
 529   //   indexbyte1
 530   //   indexbyte2
 531   //
 532   // followed by:
 533   //
 534   //   return
 535 
 536   assert(name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructors");
 537   assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
 538   int size = code_size();
 539   // Check if size match
 540   if (size == 0 || size % 5 != 0) return false;
 541   address cb = code_base();
 542   int last = size - 1;
 543   if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
 544     // Does not call superclass default constructor
 545     return false;
 546   }
 547   // Check optional sequence
 548   for (int i = 4; i < last; i += 5) {
 549     if (cb[i] != Bytecodes::_aload_0) return false;
 550     if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
 551     if (cb[i+2] != Bytecodes::_putfield) return false;
 552   }
 553   return true;
 554 }
 555 
 556 
 557 bool Method::compute_has_loops_flag() {
 558   BytecodeStream bcs(this);
 559   Bytecodes::Code bc;
 560 
 561   while ((bc = bcs.next()) >= 0) {
 562     switch( bc ) {
 563       case Bytecodes::_ifeq:
 564       case Bytecodes::_ifnull:
 565       case Bytecodes::_iflt:
 566       case Bytecodes::_ifle:
 567       case Bytecodes::_ifne:
 568       case Bytecodes::_ifnonnull:
 569       case Bytecodes::_ifgt:
 570       case Bytecodes::_ifge:
 571       case Bytecodes::_if_icmpeq:
 572       case Bytecodes::_if_icmpne:
 573       case Bytecodes::_if_icmplt:
 574       case Bytecodes::_if_icmpgt:
 575       case Bytecodes::_if_icmple:
 576       case Bytecodes::_if_icmpge:
 577       case Bytecodes::_if_acmpeq:
 578       case Bytecodes::_if_acmpne:
 579       case Bytecodes::_goto:
 580       case Bytecodes::_jsr:
 581         if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
 582         break;
 583 
 584       case Bytecodes::_goto_w:
 585       case Bytecodes::_jsr_w:
 586         if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
 587         break;
 588 
 589       default:
 590         break;
 591     }
 592   }
 593   _access_flags.set_loops_flag_init();
 594   return _access_flags.has_loops();
 595 }
 596 
 597 bool Method::is_final_method(AccessFlags class_access_flags) const {
 598   // or "does_not_require_vtable_entry"
 599   // default method or overpass can occur, is not final (reuses vtable entry)
 600   // private methods in classes get vtable entries for backward class compatibility.
 601   if (is_overpass() || is_default_method())  return false;
 602   return is_final() || class_access_flags.is_final();
 603 }
 604 
 605 bool Method::is_final_method() const {
 606   return is_final_method(method_holder()->access_flags());
 607 }
 608 
 609 bool Method::is_default_method() const {
 610   if (method_holder() != NULL &&
 611       method_holder()->is_interface() &&
 612       !is_abstract() && !is_private()) {
 613     return true;
 614   } else {
 615     return false;
 616   }
 617 }
 618 
 619 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
 620   if (is_final_method(class_access_flags))  return true;
 621 #ifdef ASSERT
 622   ResourceMark rm;
 623   bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
 624   if (class_access_flags.is_interface()) {
 625       assert(is_nonv == is_static() || is_nonv == is_private(),
 626              "nonvirtual unexpected for non-static, non-private: %s",
 627              name_and_sig_as_C_string());
 628   }
 629 #endif
 630   assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
 631   return vtable_index() == nonvirtual_vtable_index;
 632 }
 633 
 634 bool Method::can_be_statically_bound() const {
 635   return can_be_statically_bound(method_holder()->access_flags());
 636 }
 637 
 638 bool Method::can_be_statically_bound(InstanceKlass* context) const {
 639   return (method_holder() == context) && can_be_statically_bound();
 640 }
 641 
 642 bool Method::is_accessor() const {
 643   return is_getter() || is_setter();
 644 }
 645 
 646 bool Method::is_getter() const {
 647   if (code_size() != 5) return false;
 648   if (size_of_parameters() != 1) return false;
 649   if (java_code_at(0) != Bytecodes::_aload_0)  return false;
 650   if (java_code_at(1) != Bytecodes::_getfield) return false;
 651   switch (java_code_at(4)) {
 652     case Bytecodes::_ireturn:
 653     case Bytecodes::_lreturn:
 654     case Bytecodes::_freturn:
 655     case Bytecodes::_dreturn:
 656     case Bytecodes::_areturn:
 657       break;
 658     default:
 659       return false;
 660   }
 661   return true;
 662 }
 663 
 664 bool Method::is_setter() const {
 665   if (code_size() != 6) return false;
 666   if (java_code_at(0) != Bytecodes::_aload_0) return false;
 667   switch (java_code_at(1)) {
 668     case Bytecodes::_iload_1:
 669     case Bytecodes::_aload_1:
 670     case Bytecodes::_fload_1:
 671       if (size_of_parameters() != 2) return false;
 672       break;
 673     case Bytecodes::_dload_1:
 674     case Bytecodes::_lload_1:
 675       if (size_of_parameters() != 3) return false;
 676       break;
 677     default:
 678       return false;
 679   }
 680   if (java_code_at(2) != Bytecodes::_putfield) return false;
 681   if (java_code_at(5) != Bytecodes::_return)   return false;
 682   return true;
 683 }
 684 
 685 bool Method::is_constant_getter() const {
 686   int last_index = code_size() - 1;
 687   // Check if the first 1-3 bytecodes are a constant push
 688   // and the last bytecode is a return.
 689   return (2 <= code_size() && code_size() <= 4 &&
 690           Bytecodes::is_const(java_code_at(0)) &&
 691           Bytecodes::length_for(java_code_at(0)) == last_index &&
 692           Bytecodes::is_return(java_code_at(last_index)));
 693 }
 694 
 695 bool Method::is_initializer() const {
 696   return is_object_initializer() || is_static_initializer();
 697 }
 698 
 699 bool Method::has_valid_initializer_flags() const {
 700   return (is_static() ||
 701           method_holder()->major_version() < 51);
 702 }
 703 
 704 bool Method::is_static_initializer() const {
 705   // For classfiles version 51 or greater, ensure that the clinit method is
 706   // static.  Non-static methods with the name "<clinit>" are not static
 707   // initializers. (older classfiles exempted for backward compatibility)
 708   return name() == vmSymbols::class_initializer_name() &&
 709          has_valid_initializer_flags();
 710 }
 711 
 712 bool Method::is_object_initializer() const {
 713    return name() == vmSymbols::object_initializer_name();
 714 }
 715 
 716 bool Method::needs_clinit_barrier() const {
 717   return is_static() && !method_holder()->is_initialized();
 718 }
 719 
 720 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
 721   int length = method->checked_exceptions_length();
 722   if (length == 0) {  // common case
 723     return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
 724   } else {
 725     methodHandle h_this(THREAD, method);
 726     objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
 727     objArrayHandle mirrors (THREAD, m_oop);
 728     for (int i = 0; i < length; i++) {
 729       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
 730       Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
 731       assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
 732       mirrors->obj_at_put(i, k->java_mirror());
 733     }
 734     return mirrors;
 735   }
 736 };
 737 
 738 
 739 int Method::line_number_from_bci(int bci) const {
 740   int best_bci  =  0;
 741   int best_line = -1;
 742   if (bci == SynchronizationEntryBCI) bci = 0;
 743   if (0 <= bci && bci < code_size() && has_linenumber_table()) {
 744     // The line numbers are a short array of 2-tuples [start_pc, line_number].
 745     // Not necessarily sorted and not necessarily one-to-one.
 746     CompressedLineNumberReadStream stream(compressed_linenumber_table());
 747     while (stream.read_pair()) {
 748       if (stream.bci() == bci) {
 749         // perfect match
 750         return stream.line();
 751       } else {
 752         // update best_bci/line
 753         if (stream.bci() < bci && stream.bci() >= best_bci) {
 754           best_bci  = stream.bci();
 755           best_line = stream.line();
 756         }
 757       }
 758     }
 759   }
 760   return best_line;
 761 }
 762 
 763 
 764 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
 765   if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
 766     Thread *thread = Thread::current();
 767     Symbol* klass_name = constants()->klass_name_at(klass_index);
 768     Handle loader(thread, method_holder()->class_loader());
 769     Handle prot  (thread, method_holder()->protection_domain());
 770     return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
 771   } else {
 772     return true;
 773   }
 774 }
 775 
 776 
 777 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
 778   int klass_index = constants()->klass_ref_index_at(refinfo_index);
 779   if (must_be_resolved) {
 780     // Make sure klass is resolved in constantpool.
 781     if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
 782   }
 783   return is_klass_loaded_by_klass_index(klass_index);
 784 }
 785 
 786 
 787 void Method::set_native_function(address function, bool post_event_flag) {
 788   assert(function != NULL, "use clear_native_function to unregister natives");
 789   assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
 790   address* native_function = native_function_addr();
 791 
 792   // We can see racers trying to place the same native function into place. Once
 793   // is plenty.
 794   address current = *native_function;
 795   if (current == function) return;
 796   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
 797       function != NULL) {
 798     // native_method_throw_unsatisfied_link_error_entry() should only
 799     // be passed when post_event_flag is false.
 800     assert(function !=
 801       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 802       "post_event_flag mis-match");
 803 
 804     // post the bind event, and possible change the bind function
 805     JvmtiExport::post_native_method_bind(this, &function);
 806   }
 807   *native_function = function;
 808   // This function can be called more than once. We must make sure that we always
 809   // use the latest registered method -> check if a stub already has been generated.
 810   // If so, we have to make it not_entrant.
 811   CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates
 812   if (nm != NULL) {
 813     nm->make_not_entrant();
 814   }
 815 }
 816 
 817 
 818 bool Method::has_native_function() const {
 819   if (is_method_handle_intrinsic())
 820     return false;  // special-cased in SharedRuntime::generate_native_wrapper
 821   address func = native_function();
 822   return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
 823 }
 824 
 825 
 826 void Method::clear_native_function() {
 827   // Note: is_method_handle_intrinsic() is allowed here.
 828   set_native_function(
 829     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 830     !native_bind_event_is_interesting);
 831   this->unlink_code();
 832 }
 833 
 834 
 835 void Method::set_signature_handler(address handler) {
 836   address* signature_handler =  signature_handler_addr();
 837   *signature_handler = handler;
 838 }
 839 
 840 
 841 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
 842   assert(reason != NULL, "must provide a reason");
 843   if (PrintCompilation && report) {
 844     ttyLocker ttyl;
 845     tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
 846     if (comp_level == CompLevel_all) {
 847       tty->print("all levels ");
 848     } else {
 849       tty->print("level %d ", comp_level);
 850     }
 851     this->print_short_name(tty);
 852     int size = this->code_size();
 853     if (size > 0) {
 854       tty->print(" (%d bytes)", size);
 855     }
 856     if (reason != NULL) {
 857       tty->print("   %s", reason);
 858     }
 859     tty->cr();
 860   }
 861   if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
 862     ttyLocker ttyl;
 863     xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
 864                      os::current_thread_id(), is_osr, comp_level);
 865     if (reason != NULL) {
 866       xtty->print(" reason=\'%s\'", reason);
 867     }
 868     xtty->method(this);
 869     xtty->stamp();
 870     xtty->end_elem();
 871   }
 872 }
 873 
 874 bool Method::is_always_compilable() const {
 875   // Generated adapters must be compiled
 876   if (is_method_handle_intrinsic() && is_synthetic()) {
 877     assert(!is_not_c1_compilable(), "sanity check");
 878     assert(!is_not_c2_compilable(), "sanity check");
 879     return true;
 880   }
 881 
 882   return false;
 883 }
 884 
 885 bool Method::is_not_compilable(int comp_level) const {
 886   if (number_of_breakpoints() > 0)
 887     return true;
 888   if (is_always_compilable())
 889     return false;
 890   if (comp_level == CompLevel_any)
 891     return is_not_c1_compilable() || is_not_c2_compilable();
 892   if (is_c1_compile(comp_level))
 893     return is_not_c1_compilable();
 894   if (is_c2_compile(comp_level))
 895     return is_not_c2_compilable();
 896   return false;
 897 }
 898 
 899 // call this when compiler finds that this method is not compilable
 900 void Method::set_not_compilable(const char* reason, int comp_level, bool report) {
 901   if (is_always_compilable()) {
 902     // Don't mark a method which should be always compilable
 903     return;
 904   }
 905   print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
 906   if (comp_level == CompLevel_all) {
 907     set_not_c1_compilable();
 908     set_not_c2_compilable();
 909   } else {
 910     if (is_c1_compile(comp_level))
 911       set_not_c1_compilable();
 912     if (is_c2_compile(comp_level))
 913       set_not_c2_compilable();
 914   }
 915   CompilationPolicy::policy()->disable_compilation(this);
 916   assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
 917 }
 918 
 919 bool Method::is_not_osr_compilable(int comp_level) const {
 920   if (is_not_compilable(comp_level))
 921     return true;
 922   if (comp_level == CompLevel_any)
 923     return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
 924   if (is_c1_compile(comp_level))
 925     return is_not_c1_osr_compilable();
 926   if (is_c2_compile(comp_level))
 927     return is_not_c2_osr_compilable();
 928   return false;
 929 }
 930 
 931 void Method::set_not_osr_compilable(const char* reason, int comp_level, bool report) {
 932   print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
 933   if (comp_level == CompLevel_all) {
 934     set_not_c1_osr_compilable();
 935     set_not_c2_osr_compilable();
 936   } else {
 937     if (is_c1_compile(comp_level))
 938       set_not_c1_osr_compilable();
 939     if (is_c2_compile(comp_level))
 940       set_not_c2_osr_compilable();
 941   }
 942   CompilationPolicy::policy()->disable_compilation(this);
 943   assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
 944 }
 945 
 946 // Revert to using the interpreter and clear out the nmethod
 947 void Method::clear_code() {
 948   // this may be NULL if c2i adapters have not been made yet
 949   // Only should happen at allocate time.
 950   if (adapter() == NULL) {
 951     _from_compiled_entry    = NULL;
 952   } else {
 953     _from_compiled_entry    = adapter()->get_c2i_entry();
 954   }
 955   OrderAccess::storestore();
 956   _from_interpreted_entry = _i2i_entry;
 957   OrderAccess::storestore();
 958   _code = NULL;
 959 }
 960 
 961 void Method::unlink_code(CompiledMethod *compare) {
 962   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
 963   // We need to check if either the _code or _from_compiled_code_entry_point
 964   // refer to this nmethod because there is a race in setting these two fields
 965   // in Method* as seen in bugid 4947125.
 966   // If the vep() points to the zombie nmethod, the memory for the nmethod
 967   // could be flushed and the compiler and vtable stubs could still call
 968   // through it.
 969   if (code() == compare ||
 970       from_compiled_entry() == compare->verified_entry_point()) {
 971     clear_code();
 972   }
 973 }
 974 
 975 void Method::unlink_code() {
 976   MutexLocker ml(CompiledMethod_lock->owned_by_self() ? NULL : CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
 977   clear_code();
 978 }
 979 
 980 #if INCLUDE_CDS
 981 // Called by class data sharing to remove any entry points (which are not shared)
 982 void Method::unlink_method() {
 983   _code = NULL;
 984 
 985   Arguments::assert_is_dumping_archive();
 986   // Set the values to what they should be at run time. Note that
 987   // this Method can no longer be executed during dump time.
 988   _i2i_entry = Interpreter::entry_for_cds_method(this);
 989   _from_interpreted_entry = _i2i_entry;
 990 
 991   if (DynamicDumpSharedSpaces) {
 992     assert(_from_compiled_entry != NULL, "sanity");
 993   } else {
 994     // TODO: Simplify the adapter trampoline allocation for static archiving.
 995     //       Remove the use of CDSAdapterHandlerEntry.
 996     CDSAdapterHandlerEntry* cds_adapter = (CDSAdapterHandlerEntry*)adapter();
 997     constMethod()->set_adapter_trampoline(cds_adapter->get_adapter_trampoline());
 998     _from_compiled_entry = cds_adapter->get_c2i_entry_trampoline();
 999     assert(*((int*)_from_compiled_entry) == 0,
1000            "must be NULL during dump time, to be initialized at run time");
1001   }
1002 
1003   if (is_native()) {
1004     *native_function_addr() = NULL;
1005     set_signature_handler(NULL);
1006   }
1007   NOT_PRODUCT(set_compiled_invocation_count(0);)
1008 
1009   set_method_data(NULL);
1010   clear_method_counters();
1011 }
1012 #endif
1013 
1014 /****************************************************************************
1015 // The following illustrates how the entries work for CDS shared Methods:
1016 //
1017 // Our goal is to delay writing into a shared Method until it's compiled.
1018 // Hence, we want to determine the initial values for _i2i_entry,
1019 // _from_interpreted_entry and _from_compiled_entry during CDS dump time.
1020 //
1021 // In this example, both Methods A and B have the _i2i_entry of "zero_locals".
1022 // They also have similar signatures so that they will share the same
1023 // AdapterHandlerEntry.
1024 //
1025 // _adapter_trampoline points to a fixed location in the RW section of
1026 // the CDS archive. This location initially contains a NULL pointer. When the
1027 // first of method A or B is linked, an AdapterHandlerEntry is allocated
1028 // dynamically, and its c2i/i2c entries are generated.
1029 //
1030 // _i2i_entry and _from_interpreted_entry initially points to the same
1031 // (fixed) location in the CODE section of the CDS archive. This contains
1032 // an unconditional branch to the actual entry for "zero_locals", which is
1033 // generated at run time and may be on an arbitrary address. Thus, the
1034 // unconditional branch is also generated at run time to jump to the correct
1035 // address.
1036 //
1037 // Similarly, _from_compiled_entry points to a fixed address in the CODE
1038 // section. This address has enough space for an unconditional branch
1039 // instruction, and is initially zero-filled. After the AdapterHandlerEntry is
1040 // initialized, and the address for the actual c2i_entry is known, we emit a
1041 // branch instruction here to branch to the actual c2i_entry.
1042 //
1043 // The effect of the extra branch on the i2i and c2i entries is negligible.
1044 //
1045 // The reason for putting _adapter_trampoline in RO is many shared Methods
1046 // share the same AdapterHandlerEntry, so we can save space in the RW section
1047 // by having the extra indirection.
1048 
1049 
1050 [Method A: RW]
1051   _constMethod ----> [ConstMethod: RO]
1052                        _adapter_trampoline -----------+
1053                                                       |
1054   _i2i_entry              (same value as method B)    |
1055   _from_interpreted_entry (same value as method B)    |
1056   _from_compiled_entry    (same value as method B)    |
1057                                                       |
1058                                                       |
1059 [Method B: RW]                               +--------+
1060   _constMethod ----> [ConstMethod: RO]       |
1061                        _adapter_trampoline --+--->(AdapterHandlerEntry* ptr: RW)-+
1062                                                                                  |
1063                                                  +-------------------------------+
1064                                                  |
1065                                                  +----> [AdapterHandlerEntry] (allocated at run time)
1066                                                               _fingerprint
1067                                                               _c2i_entry ---------------------------------+->[c2i entry..]
1068  _i2i_entry  -------------+                                   _i2c_entry ---------------+-> [i2c entry..] |
1069  _from_interpreted_entry  |                                   _c2i_unverified_entry     |                 |
1070          |                |                                   _c2i_no_clinit_check_entry|                 |
1071          |                |  (_cds_entry_table: CODE)                                   |                 |
1072          |                +->[0]: jmp _entry_table[0] --> (i2i_entry_for "zero_locals") |                 |
1073          |                |                               (allocated at run time)       |                 |
1074          |                |  ...                           [asm code ...]               |                 |
1075          +-[not compiled]-+  [n]: jmp _entry_table[n]                                   |                 |
1076          |                                                                              |                 |
1077          |                                                                              |                 |
1078          +-[compiled]-------------------------------------------------------------------+                 |
1079                                                                                                           |
1080  _from_compiled_entry------------>  (_c2i_entry_trampoline: CODE)                                         |
1081                                     [jmp c2i_entry] ------------------------------------------------------+
1082 
1083 ***/
1084 
1085 // Called when the method_holder is getting linked. Setup entrypoints so the method
1086 // is ready to be called from interpreter, compiler, and vtables.
1087 void Method::link_method(const methodHandle& h_method, TRAPS) {
1088   // If the code cache is full, we may reenter this function for the
1089   // leftover methods that weren't linked.
1090   if (is_shared()) {
1091     address entry = Interpreter::entry_for_cds_method(h_method);
1092     assert(entry != NULL && entry == _i2i_entry,
1093            "should be correctly set during dump time");
1094     if (adapter() != NULL) {
1095       return;
1096     }
1097     assert(entry == _from_interpreted_entry,
1098            "should be correctly set during dump time");
1099   } else if (_i2i_entry != NULL) {
1100     return;
1101   }
1102   assert( _code == NULL, "nothing compiled yet" );
1103 
1104   // Setup interpreter entrypoint
1105   assert(this == h_method(), "wrong h_method()" );
1106 
1107   if (!is_shared()) {
1108     assert(adapter() == NULL, "init'd to NULL");
1109     address entry = Interpreter::entry_for_method(h_method);
1110     assert(entry != NULL, "interpreter entry must be non-null");
1111     // Sets both _i2i_entry and _from_interpreted_entry
1112     set_interpreter_entry(entry);
1113   }
1114 
1115   // Don't overwrite already registered native entries.
1116   if (is_native() && !has_native_function()) {
1117     set_native_function(
1118       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1119       !native_bind_event_is_interesting);
1120   }
1121 
1122   // Setup compiler entrypoint.  This is made eagerly, so we do not need
1123   // special handling of vtables.  An alternative is to make adapters more
1124   // lazily by calling make_adapter() from from_compiled_entry() for the
1125   // normal calls.  For vtable calls life gets more complicated.  When a
1126   // call-site goes mega-morphic we need adapters in all methods which can be
1127   // called from the vtable.  We need adapters on such methods that get loaded
1128   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
1129   // problem we'll make these lazily later.
1130   (void) make_adapters(h_method, CHECK);
1131 
1132   // ONLY USE the h_method now as make_adapter may have blocked
1133 
1134 }
1135 
1136 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1137   // Adapters for compiled code are made eagerly here.  They are fairly
1138   // small (generally < 100 bytes) and quick to make (and cached and shared)
1139   // so making them eagerly shouldn't be too expensive.
1140   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1141   if (adapter == NULL ) {
1142     if (!is_init_completed()) {
1143       // Don't throw exceptions during VM initialization because java.lang.* classes
1144       // might not have been initialized, causing problems when constructing the
1145       // Java exception object.
1146       vm_exit_during_initialization("Out of space in CodeCache for adapters");
1147     } else {
1148       THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
1149     }
1150   }
1151 
1152   if (mh->is_shared()) {
1153     assert(mh->adapter() == adapter, "must be");
1154     assert(mh->_from_compiled_entry != NULL, "must be");
1155   } else {
1156     mh->set_adapter_entry(adapter);
1157     mh->_from_compiled_entry = adapter->get_c2i_entry();
1158   }
1159   return adapter->get_c2i_entry();
1160 }
1161 
1162 void Method::restore_unshareable_info(TRAPS) {
1163   assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
1164 
1165   // Since restore_unshareable_info can be called more than once for a method, don't
1166   // redo any work.
1167   if (adapter() == NULL) {
1168     methodHandle mh(THREAD, this);
1169     link_method(mh, CHECK);
1170   }
1171 }
1172 
1173 address Method::from_compiled_entry_no_trampoline() const {
1174   CompiledMethod *code = OrderAccess::load_acquire(&_code);
1175   if (code) {
1176     return code->verified_entry_point();
1177   } else {
1178     return adapter()->get_c2i_entry();
1179   }
1180 }
1181 
1182 // The verified_code_entry() must be called when a invoke is resolved
1183 // on this method.
1184 
1185 // It returns the compiled code entry point, after asserting not null.
1186 // This function is called after potential safepoints so that nmethod
1187 // or adapter that it points to is still live and valid.
1188 // This function must not hit a safepoint!
1189 address Method::verified_code_entry() {
1190   debug_only(NoSafepointVerifier nsv;)
1191   assert(_from_compiled_entry != NULL, "must be set");
1192   return _from_compiled_entry;
1193 }
1194 
1195 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1196 // (could be racing a deopt).
1197 // Not inline to avoid circular ref.
1198 bool Method::check_code() const {
1199   // cached in a register or local.  There's a race on the value of the field.
1200   CompiledMethod *code = OrderAccess::load_acquire(&_code);
1201   return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
1202 }
1203 
1204 // Install compiled code.  Instantly it can execute.
1205 void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
1206   assert_lock_strong(CompiledMethod_lock);
1207   assert( code, "use clear_code to remove code" );
1208   assert( mh->check_code(), "" );
1209 
1210   guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
1211 
1212   // These writes must happen in this order, because the interpreter will
1213   // directly jump to from_interpreted_entry which jumps to an i2c adapter
1214   // which jumps to _from_compiled_entry.
1215   mh->_code = code;             // Assign before allowing compiled code to exec
1216 
1217   int comp_level = code->comp_level();
1218   // In theory there could be a race here. In practice it is unlikely
1219   // and not worth worrying about.
1220   if (comp_level > mh->highest_comp_level()) {
1221     mh->set_highest_comp_level(comp_level);
1222   }
1223 
1224   OrderAccess::storestore();
1225   mh->_from_compiled_entry = code->verified_entry_point();
1226   OrderAccess::storestore();
1227   // Instantly compiled code can execute.
1228   if (!mh->is_method_handle_intrinsic())
1229     mh->_from_interpreted_entry = mh->get_i2c_entry();
1230 }
1231 
1232 
1233 bool Method::is_overridden_in(Klass* k) const {
1234   InstanceKlass* ik = InstanceKlass::cast(k);
1235 
1236   if (ik->is_interface()) return false;
1237 
1238   // If method is an interface, we skip it - except if it
1239   // is a miranda method
1240   if (method_holder()->is_interface()) {
1241     // Check that method is not a miranda method
1242     if (ik->lookup_method(name(), signature()) == NULL) {
1243       // No implementation exist - so miranda method
1244       return false;
1245     }
1246     return true;
1247   }
1248 
1249   assert(ik->is_subclass_of(method_holder()), "should be subklass");
1250   if (!has_vtable_index()) {
1251     return false;
1252   } else {
1253     Method* vt_m = ik->method_at_vtable(vtable_index());
1254     return vt_m != this;
1255   }
1256 }
1257 
1258 
1259 // give advice about whether this Method* should be cached or not
1260 bool Method::should_not_be_cached() const {
1261   if (is_old()) {
1262     // This method has been redefined. It is either EMCP or obsolete
1263     // and we don't want to cache it because that would pin the method
1264     // down and prevent it from being collectible if and when it
1265     // finishes executing.
1266     return true;
1267   }
1268 
1269   // caching this method should be just fine
1270   return false;
1271 }
1272 
1273 
1274 /**
1275  *  Returns true if this is one of the specially treated methods for
1276  *  security related stack walks (like Reflection.getCallerClass).
1277  */
1278 bool Method::is_ignored_by_security_stack_walk() const {
1279   if (intrinsic_id() == vmIntrinsics::_invoke) {
1280     // This is Method.invoke() -- ignore it
1281     return true;
1282   }
1283   if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1284     // This is an auxilary frame -- ignore it
1285     return true;
1286   }
1287   if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1288     // This is an internal adapter frame for method handles -- ignore it
1289     return true;
1290   }
1291   return false;
1292 }
1293 
1294 
1295 // Constant pool structure for invoke methods:
1296 enum {
1297   _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.
1298   _imcp_invoke_signature,       // utf8: (variable Symbol*)
1299   _imcp_limit
1300 };
1301 
1302 // Test if this method is an MH adapter frame generated by Java code.
1303 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1304 bool Method::is_compiled_lambda_form() const {
1305   return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1306 }
1307 
1308 // Test if this method is an internal MH primitive method.
1309 bool Method::is_method_handle_intrinsic() const {
1310   vmIntrinsics::ID iid = intrinsic_id();
1311   return (MethodHandles::is_signature_polymorphic(iid) &&
1312           MethodHandles::is_signature_polymorphic_intrinsic(iid));
1313 }
1314 
1315 bool Method::has_member_arg() const {
1316   vmIntrinsics::ID iid = intrinsic_id();
1317   return (MethodHandles::is_signature_polymorphic(iid) &&
1318           MethodHandles::has_member_arg(iid));
1319 }
1320 
1321 // Make an instance of a signature-polymorphic internal MH primitive.
1322 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1323                                                          Symbol* signature,
1324                                                          TRAPS) {
1325   ResourceMark rm;
1326   methodHandle empty;
1327 
1328   InstanceKlass* holder = SystemDictionary::MethodHandle_klass();
1329   Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1330   assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1331   if (TraceMethodHandles) {
1332     tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1333   }
1334 
1335   // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1336   name->increment_refcount();
1337   signature->increment_refcount();
1338 
1339   int cp_length = _imcp_limit;
1340   ClassLoaderData* loader_data = holder->class_loader_data();
1341   constantPoolHandle cp;
1342   {
1343     ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1344     cp = constantPoolHandle(THREAD, cp_oop);
1345   }
1346   cp->set_pool_holder(holder);
1347   cp->symbol_at_put(_imcp_invoke_name,       name);
1348   cp->symbol_at_put(_imcp_invoke_signature,  signature);
1349   cp->set_has_preresolution();
1350 
1351   // decide on access bits:  public or not?
1352   int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1353   bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1354   if (must_be_static)  flags_bits |= JVM_ACC_STATIC;
1355   assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1356 
1357   methodHandle m;
1358   {
1359     InlineTableSizes sizes;
1360     Method* m_oop = Method::allocate(loader_data, 0,
1361                                      accessFlags_from(flags_bits), &sizes,
1362                                      ConstMethod::NORMAL, CHECK_(empty));
1363     m = methodHandle(THREAD, m_oop);
1364   }
1365   m->set_constants(cp());
1366   m->set_name_index(_imcp_invoke_name);
1367   m->set_signature_index(_imcp_invoke_signature);
1368   assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1369   assert(m->signature() == signature, "");
1370   ResultTypeFinder rtf(signature);
1371   m->constMethod()->set_result_type(rtf.type());
1372   m->compute_size_of_parameters(THREAD);
1373   m->init_intrinsic_id();
1374   assert(m->is_method_handle_intrinsic(), "");
1375 #ifdef ASSERT
1376   if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();
1377   assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1378   assert(m->intrinsic_id() == iid, "correctly predicted iid");
1379 #endif //ASSERT
1380 
1381   // Finally, set up its entry points.
1382   assert(m->can_be_statically_bound(), "");
1383   m->set_vtable_index(Method::nonvirtual_vtable_index);
1384   m->link_method(m, CHECK_(empty));
1385 
1386   if (TraceMethodHandles && (Verbose || WizardMode)) {
1387     ttyLocker ttyl;
1388     m->print_on(tty);
1389   }
1390 
1391   return m;
1392 }
1393 
1394 Klass* Method::check_non_bcp_klass(Klass* klass) {
1395   if (klass != NULL && klass->class_loader() != NULL) {
1396     if (klass->is_objArray_klass())
1397       klass = ObjArrayKlass::cast(klass)->bottom_klass();
1398     return klass;
1399   }
1400   return NULL;
1401 }
1402 
1403 
1404 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1405                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1406   // Code below does not work for native methods - they should never get rewritten anyway
1407   assert(!m->is_native(), "cannot rewrite native methods");
1408   // Allocate new Method*
1409   AccessFlags flags = m->access_flags();
1410 
1411   ConstMethod* cm = m->constMethod();
1412   int checked_exceptions_len = cm->checked_exceptions_length();
1413   int localvariable_len = cm->localvariable_table_length();
1414   int exception_table_len = cm->exception_table_length();
1415   int method_parameters_len = cm->method_parameters_length();
1416   int method_annotations_len = cm->method_annotations_length();
1417   int parameter_annotations_len = cm->parameter_annotations_length();
1418   int type_annotations_len = cm->type_annotations_length();
1419   int default_annotations_len = cm->default_annotations_length();
1420 
1421   InlineTableSizes sizes(
1422       localvariable_len,
1423       new_compressed_linenumber_size,
1424       exception_table_len,
1425       checked_exceptions_len,
1426       method_parameters_len,
1427       cm->generic_signature_index(),
1428       method_annotations_len,
1429       parameter_annotations_len,
1430       type_annotations_len,
1431       default_annotations_len,
1432       0);
1433 
1434   ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1435   Method* newm_oop = Method::allocate(loader_data,
1436                                       new_code_length,
1437                                       flags,
1438                                       &sizes,
1439                                       m->method_type(),
1440                                       CHECK_(methodHandle()));
1441   methodHandle newm (THREAD, newm_oop);
1442 
1443   // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1444   ConstMethod* newcm = newm->constMethod();
1445   int new_const_method_size = newm->constMethod()->size();
1446 
1447   // This works because the source and target are both Methods. Some compilers
1448   // (e.g., clang) complain that the target vtable pointer will be stomped,
1449   // so cast away newm()'s and m()'s Methodness.
1450   memcpy((void*)newm(), (void*)m(), sizeof(Method));
1451 
1452   // Create shallow copy of ConstMethod.
1453   memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1454 
1455   // Reset correct method/const method, method size, and parameter info
1456   newm->set_constMethod(newcm);
1457   newm->constMethod()->set_code_size(new_code_length);
1458   newm->constMethod()->set_constMethod_size(new_const_method_size);
1459   assert(newm->code_size() == new_code_length, "check");
1460   assert(newm->method_parameters_length() == method_parameters_len, "check");
1461   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1462   assert(newm->exception_table_length() == exception_table_len, "check");
1463   assert(newm->localvariable_table_length() == localvariable_len, "check");
1464   // Copy new byte codes
1465   memcpy(newm->code_base(), new_code, new_code_length);
1466   // Copy line number table
1467   if (new_compressed_linenumber_size > 0) {
1468     memcpy(newm->compressed_linenumber_table(),
1469            new_compressed_linenumber_table,
1470            new_compressed_linenumber_size);
1471   }
1472   // Copy method_parameters
1473   if (method_parameters_len > 0) {
1474     memcpy(newm->method_parameters_start(),
1475            m->method_parameters_start(),
1476            method_parameters_len * sizeof(MethodParametersElement));
1477   }
1478   // Copy checked_exceptions
1479   if (checked_exceptions_len > 0) {
1480     memcpy(newm->checked_exceptions_start(),
1481            m->checked_exceptions_start(),
1482            checked_exceptions_len * sizeof(CheckedExceptionElement));
1483   }
1484   // Copy exception table
1485   if (exception_table_len > 0) {
1486     memcpy(newm->exception_table_start(),
1487            m->exception_table_start(),
1488            exception_table_len * sizeof(ExceptionTableElement));
1489   }
1490   // Copy local variable number table
1491   if (localvariable_len > 0) {
1492     memcpy(newm->localvariable_table_start(),
1493            m->localvariable_table_start(),
1494            localvariable_len * sizeof(LocalVariableTableElement));
1495   }
1496   // Copy stackmap table
1497   if (m->has_stackmap_table()) {
1498     int code_attribute_length = m->stackmap_data()->length();
1499     Array<u1>* stackmap_data =
1500       MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1501     memcpy((void*)stackmap_data->adr_at(0),
1502            (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1503     newm->set_stackmap_data(stackmap_data);
1504   }
1505 
1506   // copy annotations over to new method
1507   newcm->copy_annotations_from(loader_data, cm, CHECK_NULL);
1508   return newm;
1509 }
1510 
1511 vmSymbols::SID Method::klass_id_for_intrinsics(const Klass* holder) {
1512   // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1513   // because we are not loading from core libraries
1514   // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1515   // which does not use the class default class loader so we check for its loader here
1516   const InstanceKlass* ik = InstanceKlass::cast(holder);
1517   if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1518     return vmSymbols::NO_SID;   // regardless of name, no intrinsics here
1519   }
1520 
1521   // see if the klass name is well-known:
1522   Symbol* klass_name = ik->name();
1523   return vmSymbols::find_sid(klass_name);
1524 }
1525 
1526 void Method::init_intrinsic_id() {
1527   assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1528   const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1529   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1530   assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1531 
1532   // the klass name is well-known:
1533   vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1534   assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1535 
1536   // ditto for method and signature:
1537   vmSymbols::SID  name_id = vmSymbols::find_sid(name());
1538   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1539       && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1540       && name_id == vmSymbols::NO_SID) {
1541     return;
1542   }
1543   vmSymbols::SID   sig_id = vmSymbols::find_sid(signature());
1544   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1545       && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1546       && sig_id == vmSymbols::NO_SID) {
1547     return;
1548   }
1549   jshort flags = access_flags().as_short();
1550 
1551   vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1552   if (id != vmIntrinsics::_none) {
1553     set_intrinsic_id(id);
1554     if (id == vmIntrinsics::_Class_cast) {
1555       // Even if the intrinsic is rejected, we want to inline this simple method.
1556       set_force_inline(true);
1557     }
1558     return;
1559   }
1560 
1561   // A few slightly irregular cases:
1562   switch (klass_id) {
1563   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1564     // Second chance: check in regular Math.
1565     switch (name_id) {
1566     case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1567     case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1568     case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1569       // pretend it is the corresponding method in the non-strict class:
1570       klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1571       id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1572       break;
1573     default:
1574       break;
1575     }
1576     break;
1577 
1578   // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1579   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1580   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1581     if (!is_native())  break;
1582     id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1583     if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1584       id = vmIntrinsics::_none;
1585     break;
1586 
1587   default:
1588     break;
1589   }
1590 
1591   if (id != vmIntrinsics::_none) {
1592     // Set up its iid.  It is an alias method.
1593     set_intrinsic_id(id);
1594     return;
1595   }
1596 }
1597 
1598 // These two methods are static since a GC may move the Method
1599 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1600   if (!THREAD->can_call_java()) {
1601     // There is nothing useful this routine can do from within the Compile thread.
1602     // Hopefully, the signature contains only well-known classes.
1603     // We could scan for this and return true/false, but the caller won't care.
1604     return false;
1605   }
1606   bool sig_is_loaded = true;
1607   Handle class_loader(THREAD, m->method_holder()->class_loader());
1608   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1609   ResourceMark rm(THREAD);
1610   Symbol*  signature = m->signature();
1611   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1612     if (ss.is_object()) {
1613       Symbol* sym = ss.as_symbol();
1614       Symbol*  name  = sym;
1615       Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1616                                              protection_domain, THREAD);
1617       // We are loading classes eagerly. If a ClassNotFoundException or
1618       // a LinkageError was generated, be sure to ignore it.
1619       if (HAS_PENDING_EXCEPTION) {
1620         if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1621             PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1622           CLEAR_PENDING_EXCEPTION;
1623         } else {
1624           return false;
1625         }
1626       }
1627       if( klass == NULL) { sig_is_loaded = false; }
1628     }
1629   }
1630   return sig_is_loaded;
1631 }
1632 
1633 bool Method::has_unloaded_classes_in_signature(const methodHandle& m, TRAPS) {
1634   Handle class_loader(THREAD, m->method_holder()->class_loader());
1635   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1636   ResourceMark rm(THREAD);
1637   Symbol*  signature = m->signature();
1638   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1639     if (ss.type() == T_OBJECT) {
1640       Symbol* name = ss.as_symbol_or_null();
1641       if (name == NULL) return true;
1642       Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1643       if (klass == NULL) return true;
1644     }
1645   }
1646   return false;
1647 }
1648 
1649 // Exposed so field engineers can debug VM
1650 void Method::print_short_name(outputStream* st) {
1651   ResourceMark rm;
1652 #ifdef PRODUCT
1653   st->print(" %s::", method_holder()->external_name());
1654 #else
1655   st->print(" %s::", method_holder()->internal_name());
1656 #endif
1657   name()->print_symbol_on(st);
1658   if (WizardMode) signature()->print_symbol_on(st);
1659   else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1660     MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1661 }
1662 
1663 // Comparer for sorting an object array containing
1664 // Method*s.
1665 static int method_comparator(Method* a, Method* b) {
1666   return a->name()->fast_compare(b->name());
1667 }
1668 
1669 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1670 // default_methods also uses this without the ordering for fast find_method
1671 void Method::sort_methods(Array<Method*>* methods, bool set_idnums, method_comparator_func func) {
1672   int length = methods->length();
1673   if (length > 1) {
1674     if (func == NULL) {
1675       func = method_comparator;
1676     }
1677     {
1678       NoSafepointVerifier nsv;
1679       QuickSort::sort(methods->data(), length, func, /*idempotent=*/false);
1680     }
1681     // Reset method ordering
1682     if (set_idnums) {
1683       for (int i = 0; i < length; i++) {
1684         Method* m = methods->at(i);
1685         m->set_method_idnum(i);
1686         m->set_orig_method_idnum(i);
1687       }
1688     }
1689   }
1690 }
1691 
1692 //-----------------------------------------------------------------------------------
1693 // Non-product code unless JVM/TI needs it
1694 
1695 #if !defined(PRODUCT) || INCLUDE_JVMTI
1696 class SignatureTypePrinter : public SignatureTypeNames {
1697  private:
1698   outputStream* _st;
1699   bool _use_separator;
1700 
1701   void type_name(const char* name) {
1702     if (_use_separator) _st->print(", ");
1703     _st->print("%s", name);
1704     _use_separator = true;
1705   }
1706 
1707  public:
1708   SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1709     _st = st;
1710     _use_separator = false;
1711   }
1712 
1713   void print_parameters()              { _use_separator = false; iterate_parameters(); }
1714   void print_returntype()              { _use_separator = false; iterate_returntype(); }
1715 };
1716 
1717 
1718 void Method::print_name(outputStream* st) {
1719   Thread *thread = Thread::current();
1720   ResourceMark rm(thread);
1721   st->print("%s ", is_static() ? "static" : "virtual");
1722   if (WizardMode) {
1723     st->print("%s.", method_holder()->internal_name());
1724     name()->print_symbol_on(st);
1725     signature()->print_symbol_on(st);
1726   } else {
1727     SignatureTypePrinter sig(signature(), st);
1728     sig.print_returntype();
1729     st->print(" %s.", method_holder()->internal_name());
1730     name()->print_symbol_on(st);
1731     st->print("(");
1732     sig.print_parameters();
1733     st->print(")");
1734   }
1735 }
1736 #endif // !PRODUCT || INCLUDE_JVMTI
1737 
1738 
1739 void Method::print_codes_on(outputStream* st) const {
1740   print_codes_on(0, code_size(), st);
1741 }
1742 
1743 void Method::print_codes_on(int from, int to, outputStream* st) const {
1744   Thread *thread = Thread::current();
1745   ResourceMark rm(thread);
1746   methodHandle mh (thread, (Method*)this);
1747   BytecodeStream s(mh);
1748   s.set_interval(from, to);
1749   BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1750   while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1751 }
1752 
1753 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1754   _bci = 0;
1755   _line = 0;
1756 };
1757 
1758 bool CompressedLineNumberReadStream::read_pair() {
1759   jubyte next = read_byte();
1760   // Check for terminator
1761   if (next == 0) return false;
1762   if (next == 0xFF) {
1763     // Escape character, regular compression used
1764     _bci  += read_signed_int();
1765     _line += read_signed_int();
1766   } else {
1767     // Single byte compression used
1768     _bci  += next >> 3;
1769     _line += next & 0x7;
1770   }
1771   return true;
1772 }
1773 
1774 #if INCLUDE_JVMTI
1775 
1776 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1777   BreakpointInfo* bp = method_holder()->breakpoints();
1778   for (; bp != NULL; bp = bp->next()) {
1779     if (bp->match(this, bci)) {
1780       return bp->orig_bytecode();
1781     }
1782   }
1783   {
1784     ResourceMark rm;
1785     fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1786   }
1787   return Bytecodes::_shouldnotreachhere;
1788 }
1789 
1790 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1791   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1792   BreakpointInfo* bp = method_holder()->breakpoints();
1793   for (; bp != NULL; bp = bp->next()) {
1794     if (bp->match(this, bci)) {
1795       bp->set_orig_bytecode(code);
1796       // and continue, in case there is more than one
1797     }
1798   }
1799 }
1800 
1801 void Method::set_breakpoint(int bci) {
1802   InstanceKlass* ik = method_holder();
1803   BreakpointInfo *bp = new BreakpointInfo(this, bci);
1804   bp->set_next(ik->breakpoints());
1805   ik->set_breakpoints(bp);
1806   // do this last:
1807   bp->set(this);
1808 }
1809 
1810 static void clear_matches(Method* m, int bci) {
1811   InstanceKlass* ik = m->method_holder();
1812   BreakpointInfo* prev_bp = NULL;
1813   BreakpointInfo* next_bp;
1814   for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1815     next_bp = bp->next();
1816     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1817     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1818       // do this first:
1819       bp->clear(m);
1820       // unhook it
1821       if (prev_bp != NULL)
1822         prev_bp->set_next(next_bp);
1823       else
1824         ik->set_breakpoints(next_bp);
1825       delete bp;
1826       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1827       // at same location. So we have multiple matching (method_index and bci)
1828       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1829       // breakpoint for clear_breakpoint request and keep all other method versions
1830       // BreakpointInfo for future clear_breakpoint request.
1831       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1832       // which is being called when class is unloaded. We delete all the Breakpoint
1833       // information for all versions of method. We may not correctly restore the original
1834       // bytecode in all method versions, but that is ok. Because the class is being unloaded
1835       // so these methods won't be used anymore.
1836       if (bci >= 0) {
1837         break;
1838       }
1839     } else {
1840       // This one is a keeper.
1841       prev_bp = bp;
1842     }
1843   }
1844 }
1845 
1846 void Method::clear_breakpoint(int bci) {
1847   assert(bci >= 0, "");
1848   clear_matches(this, bci);
1849 }
1850 
1851 void Method::clear_all_breakpoints() {
1852   clear_matches(this, -1);
1853 }
1854 
1855 #endif // INCLUDE_JVMTI
1856 
1857 int Method::invocation_count() {
1858   MethodCounters *mcs = method_counters();
1859   if (TieredCompilation) {
1860     MethodData* const mdo = method_data();
1861     if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1862         ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1863       return InvocationCounter::count_limit;
1864     } else {
1865       return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1866              ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1867     }
1868   } else {
1869     return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1870   }
1871 }
1872 
1873 int Method::backedge_count() {
1874   MethodCounters *mcs = method_counters();
1875   if (TieredCompilation) {
1876     MethodData* const mdo = method_data();
1877     if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1878         ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1879       return InvocationCounter::count_limit;
1880     } else {
1881       return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1882              ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1883     }
1884   } else {
1885     return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1886   }
1887 }
1888 
1889 int Method::highest_comp_level() const {
1890   const MethodCounters* mcs = method_counters();
1891   if (mcs != NULL) {
1892     return mcs->highest_comp_level();
1893   } else {
1894     return CompLevel_none;
1895   }
1896 }
1897 
1898 int Method::highest_osr_comp_level() const {
1899   const MethodCounters* mcs = method_counters();
1900   if (mcs != NULL) {
1901     return mcs->highest_osr_comp_level();
1902   } else {
1903     return CompLevel_none;
1904   }
1905 }
1906 
1907 void Method::set_highest_comp_level(int level) {
1908   MethodCounters* mcs = method_counters();
1909   if (mcs != NULL) {
1910     mcs->set_highest_comp_level(level);
1911   }
1912 }
1913 
1914 void Method::set_highest_osr_comp_level(int level) {
1915   MethodCounters* mcs = method_counters();
1916   if (mcs != NULL) {
1917     mcs->set_highest_osr_comp_level(level);
1918   }
1919 }
1920 
1921 #if INCLUDE_JVMTI
1922 
1923 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1924   _bci = bci;
1925   _name_index = m->name_index();
1926   _signature_index = m->signature_index();
1927   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1928   if (_orig_bytecode == Bytecodes::_breakpoint)
1929     _orig_bytecode = m->orig_bytecode_at(_bci);
1930   _next = NULL;
1931 }
1932 
1933 void BreakpointInfo::set(Method* method) {
1934 #ifdef ASSERT
1935   {
1936     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
1937     if (code == Bytecodes::_breakpoint)
1938       code = method->orig_bytecode_at(_bci);
1939     assert(orig_bytecode() == code, "original bytecode must be the same");
1940   }
1941 #endif
1942   Thread *thread = Thread::current();
1943   *method->bcp_from(_bci) = Bytecodes::_breakpoint;
1944   method->incr_number_of_breakpoints(thread);
1945   {
1946     // Deoptimize all dependents on this method
1947     HandleMark hm(thread);
1948     methodHandle mh(thread, method);
1949     CodeCache::flush_dependents_on_method(mh);
1950   }
1951 }
1952 
1953 void BreakpointInfo::clear(Method* method) {
1954   *method->bcp_from(_bci) = orig_bytecode();
1955   assert(method->number_of_breakpoints() > 0, "must not go negative");
1956   method->decr_number_of_breakpoints(Thread::current());
1957 }
1958 
1959 #endif // INCLUDE_JVMTI
1960 
1961 // jmethodID handling
1962 
1963 // This is a block allocating object, sort of like JNIHandleBlock, only a
1964 // lot simpler.
1965 // It's allocated on the CHeap because once we allocate a jmethodID, we can
1966 // never get rid of it.
1967 
1968 static const int min_block_size = 8;
1969 
1970 class JNIMethodBlockNode : public CHeapObj<mtClass> {
1971   friend class JNIMethodBlock;
1972   Method**        _methods;
1973   int             _number_of_methods;
1974   int             _top;
1975   JNIMethodBlockNode* _next;
1976 
1977  public:
1978 
1979   JNIMethodBlockNode(int num_methods = min_block_size);
1980 
1981   ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
1982 
1983   void ensure_methods(int num_addl_methods) {
1984     if (_top < _number_of_methods) {
1985       num_addl_methods -= _number_of_methods - _top;
1986       if (num_addl_methods <= 0) {
1987         return;
1988       }
1989     }
1990     if (_next == NULL) {
1991       _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
1992     } else {
1993       _next->ensure_methods(num_addl_methods);
1994     }
1995   }
1996 };
1997 
1998 class JNIMethodBlock : public CHeapObj<mtClass> {
1999   JNIMethodBlockNode _head;
2000   JNIMethodBlockNode *_last_free;
2001  public:
2002   static Method* const _free_method;
2003 
2004   JNIMethodBlock(int initial_capacity = min_block_size)
2005       : _head(initial_capacity), _last_free(&_head) {}
2006 
2007   void ensure_methods(int num_addl_methods) {
2008     _last_free->ensure_methods(num_addl_methods);
2009   }
2010 
2011   Method** add_method(Method* m) {
2012     for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
2013       if (b->_top < b->_number_of_methods) {
2014         // top points to the next free entry.
2015         int i = b->_top;
2016         b->_methods[i] = m;
2017         b->_top++;
2018         _last_free = b;
2019         return &(b->_methods[i]);
2020       } else if (b->_top == b->_number_of_methods) {
2021         // if the next free entry ran off the block see if there's a free entry
2022         for (int i = 0; i < b->_number_of_methods; i++) {
2023           if (b->_methods[i] == _free_method) {
2024             b->_methods[i] = m;
2025             _last_free = b;
2026             return &(b->_methods[i]);
2027           }
2028         }
2029         // Only check each block once for frees.  They're very unlikely.
2030         // Increment top past the end of the block.
2031         b->_top++;
2032       }
2033       // need to allocate a next block.
2034       if (b->_next == NULL) {
2035         b->_next = _last_free = new JNIMethodBlockNode();
2036       }
2037     }
2038     guarantee(false, "Should always allocate a free block");
2039     return NULL;
2040   }
2041 
2042   bool contains(Method** m) {
2043     if (m == NULL) return false;
2044     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2045       if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2046         // This is a bit of extra checking, for two reasons.  One is
2047         // that contains() deals with pointers that are passed in by
2048         // JNI code, so making sure that the pointer is aligned
2049         // correctly is valuable.  The other is that <= and > are
2050         // technically not defined on pointers, so the if guard can
2051         // pass spuriously; no modern compiler is likely to make that
2052         // a problem, though (and if one did, the guard could also
2053         // fail spuriously, which would be bad).
2054         ptrdiff_t idx = m - b->_methods;
2055         if (b->_methods + idx == m) {
2056           return true;
2057         }
2058       }
2059     }
2060     return false;  // not found
2061   }
2062 
2063   // Doesn't really destroy it, just marks it as free so it can be reused.
2064   void destroy_method(Method** m) {
2065 #ifdef ASSERT
2066     assert(contains(m), "should be a methodID");
2067 #endif // ASSERT
2068     *m = _free_method;
2069   }
2070 
2071   // During class unloading the methods are cleared, which is different
2072   // than freed.
2073   void clear_all_methods() {
2074     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2075       for (int i = 0; i< b->_number_of_methods; i++) {
2076         b->_methods[i] = NULL;
2077       }
2078     }
2079   }
2080 #ifndef PRODUCT
2081   int count_methods() {
2082     // count all allocated methods
2083     int count = 0;
2084     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2085       for (int i = 0; i< b->_number_of_methods; i++) {
2086         if (b->_methods[i] != _free_method) count++;
2087       }
2088     }
2089     return count;
2090   }
2091 #endif // PRODUCT
2092 };
2093 
2094 // Something that can't be mistaken for an address or a markWord
2095 Method* const JNIMethodBlock::_free_method = (Method*)55;
2096 
2097 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(NULL) {
2098   _number_of_methods = MAX2(num_methods, min_block_size);
2099   _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2100   for (int i = 0; i < _number_of_methods; i++) {
2101     _methods[i] = JNIMethodBlock::_free_method;
2102   }
2103 }
2104 
2105 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
2106   ClassLoaderData* cld = loader_data;
2107   if (!SafepointSynchronize::is_at_safepoint()) {
2108     // Have to add jmethod_ids() to class loader data thread-safely.
2109     // Also have to add the method to the list safely, which the cld lock
2110     // protects as well.
2111     MutexLocker ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
2112     if (cld->jmethod_ids() == NULL) {
2113       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2114     } else {
2115       cld->jmethod_ids()->ensure_methods(capacity);
2116     }
2117   } else {
2118     // At safepoint, we are single threaded and can set this.
2119     if (cld->jmethod_ids() == NULL) {
2120       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2121     } else {
2122       cld->jmethod_ids()->ensure_methods(capacity);
2123     }
2124   }
2125 }
2126 
2127 // Add a method id to the jmethod_ids
2128 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
2129   ClassLoaderData* cld = loader_data;
2130 
2131   if (!SafepointSynchronize::is_at_safepoint()) {
2132     // Have to add jmethod_ids() to class loader data thread-safely.
2133     // Also have to add the method to the list safely, which the cld lock
2134     // protects as well.
2135     MutexLocker ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
2136     if (cld->jmethod_ids() == NULL) {
2137       cld->set_jmethod_ids(new JNIMethodBlock());
2138     }
2139     // jmethodID is a pointer to Method*
2140     return (jmethodID)cld->jmethod_ids()->add_method(m);
2141   } else {
2142     // At safepoint, we are single threaded and can set this.
2143     if (cld->jmethod_ids() == NULL) {
2144       cld->set_jmethod_ids(new JNIMethodBlock());
2145     }
2146     // jmethodID is a pointer to Method*
2147     return (jmethodID)cld->jmethod_ids()->add_method(m);
2148   }
2149 }
2150 
2151 // Mark a jmethodID as free.  This is called when there is a data race in
2152 // InstanceKlass while creating the jmethodID cache.
2153 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
2154   ClassLoaderData* cld = loader_data;
2155   Method** ptr = (Method**)m;
2156   assert(cld->jmethod_ids() != NULL, "should have method handles");
2157   cld->jmethod_ids()->destroy_method(ptr);
2158 }
2159 
2160 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2161   // Can't assert the method_holder is the same because the new method has the
2162   // scratch method holder.
2163   assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2164            == new_method->method_holder()->class_loader() ||
2165            new_method->method_holder()->class_loader() == NULL, // allow Unsafe substitution
2166          "changing to a different class loader");
2167   // Just change the method in place, jmethodID pointer doesn't change.
2168   *((Method**)jmid) = new_method;
2169 }
2170 
2171 bool Method::is_method_id(jmethodID mid) {
2172   Method* m = resolve_jmethod_id(mid);
2173   assert(m != NULL, "should be called with non-null method");
2174   InstanceKlass* ik = m->method_holder();
2175   ClassLoaderData* cld = ik->class_loader_data();
2176   if (cld->jmethod_ids() == NULL) return false;
2177   return (cld->jmethod_ids()->contains((Method**)mid));
2178 }
2179 
2180 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2181   if (mid == NULL) return NULL;
2182   Method* o = resolve_jmethod_id(mid);
2183   if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
2184     return NULL;
2185   }
2186   return o;
2187 };
2188 
2189 void Method::set_on_stack(const bool value) {
2190   // Set both the method itself and its constant pool.  The constant pool
2191   // on stack means some method referring to it is also on the stack.
2192   constants()->set_on_stack(value);
2193 
2194   bool already_set = on_stack();
2195   _access_flags.set_on_stack(value);
2196   if (value && !already_set) {
2197     MetadataOnStackMark::record(this);
2198   }
2199   assert(!value || !is_old() || is_obsolete() || is_running_emcp(),
2200          "emcp methods cannot run after emcp bit is cleared");
2201 }
2202 
2203 // Called when the class loader is unloaded to make all methods weak.
2204 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2205   loader_data->jmethod_ids()->clear_all_methods();
2206 }
2207 
2208 bool Method::has_method_vptr(const void* ptr) {
2209   Method m;
2210   // This assumes that the vtbl pointer is the first word of a C++ object.
2211   return dereference_vptr(&m) == dereference_vptr(ptr);
2212 }
2213 
2214 // Check that this pointer is valid by checking that the vtbl pointer matches
2215 bool Method::is_valid_method(const Method* m) {
2216   if (m == NULL) {
2217     return false;
2218   } else if ((intptr_t(m) & (wordSize-1)) != 0) {
2219     // Quick sanity check on pointer.
2220     return false;
2221   } else if (m->is_shared()) {
2222     return MetaspaceShared::is_valid_shared_method(m);
2223   } else if (Metaspace::contains_non_shared(m)) {
2224     return has_method_vptr((const void*)m);
2225   } else {
2226     return false;
2227   }
2228 }
2229 
2230 #ifndef PRODUCT
2231 void Method::print_jmethod_ids(const ClassLoaderData* loader_data, outputStream* out) {
2232   out->print(" jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2233 }
2234 #endif // PRODUCT
2235 
2236 
2237 // Printing
2238 
2239 #ifndef PRODUCT
2240 
2241 void Method::print_on(outputStream* st) const {
2242   ResourceMark rm;
2243   assert(is_method(), "must be method");
2244   st->print_cr("%s", internal_name());
2245   st->print_cr(" - this oop:          " INTPTR_FORMAT, p2i(this));
2246   st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();
2247   st->print   (" - constants:         " INTPTR_FORMAT " ", p2i(constants()));
2248   constants()->print_value_on(st); st->cr();
2249   st->print   (" - access:            0x%x  ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2250   st->print   (" - name:              ");    name()->print_value_on(st); st->cr();
2251   st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();
2252   st->print_cr(" - max stack:         %d",   max_stack());
2253   st->print_cr(" - max locals:        %d",   max_locals());
2254   st->print_cr(" - size of params:    %d",   size_of_parameters());
2255   st->print_cr(" - method size:       %d",   method_size());
2256   if (intrinsic_id() != vmIntrinsics::_none)
2257     st->print_cr(" - intrinsic id:      %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
2258   if (highest_comp_level() != CompLevel_none)
2259     st->print_cr(" - highest level:     %d", highest_comp_level());
2260   st->print_cr(" - vtable index:      %d",   _vtable_index);
2261   st->print_cr(" - i2i entry:         " INTPTR_FORMAT, p2i(interpreter_entry()));
2262   st->print(   " - adapters:          ");
2263   AdapterHandlerEntry* a = ((Method*)this)->adapter();
2264   if (a == NULL)
2265     st->print_cr(INTPTR_FORMAT, p2i(a));
2266   else
2267     a->print_adapter_on(st);
2268   st->print_cr(" - compiled entry     " INTPTR_FORMAT, p2i(from_compiled_entry()));
2269   st->print_cr(" - code size:         %d",   code_size());
2270   if (code_size() != 0) {
2271     st->print_cr(" - code start:        " INTPTR_FORMAT, p2i(code_base()));
2272     st->print_cr(" - code end (excl):   " INTPTR_FORMAT, p2i(code_base() + code_size()));
2273   }
2274   if (method_data() != NULL) {
2275     st->print_cr(" - method data:       " INTPTR_FORMAT, p2i(method_data()));
2276   }
2277   st->print_cr(" - checked ex length: %d",   checked_exceptions_length());
2278   if (checked_exceptions_length() > 0) {
2279     CheckedExceptionElement* table = checked_exceptions_start();
2280     st->print_cr(" - checked ex start:  " INTPTR_FORMAT, p2i(table));
2281     if (Verbose) {
2282       for (int i = 0; i < checked_exceptions_length(); i++) {
2283         st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2284       }
2285     }
2286   }
2287   if (has_linenumber_table()) {
2288     u_char* table = compressed_linenumber_table();
2289     st->print_cr(" - linenumber start:  " INTPTR_FORMAT, p2i(table));
2290     if (Verbose) {
2291       CompressedLineNumberReadStream stream(table);
2292       while (stream.read_pair()) {
2293         st->print_cr("   - line %d: %d", stream.line(), stream.bci());
2294       }
2295     }
2296   }
2297   st->print_cr(" - localvar length:   %d",   localvariable_table_length());
2298   if (localvariable_table_length() > 0) {
2299     LocalVariableTableElement* table = localvariable_table_start();
2300     st->print_cr(" - localvar start:    " INTPTR_FORMAT, p2i(table));
2301     if (Verbose) {
2302       for (int i = 0; i < localvariable_table_length(); i++) {
2303         int bci = table[i].start_bci;
2304         int len = table[i].length;
2305         const char* name = constants()->printable_name_at(table[i].name_cp_index);
2306         const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2307         int slot = table[i].slot;
2308         st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2309       }
2310     }
2311   }
2312   if (code() != NULL) {
2313     st->print   (" - compiled code: ");
2314     code()->print_value_on(st);
2315   }
2316   if (is_native()) {
2317     st->print_cr(" - native function:   " INTPTR_FORMAT, p2i(native_function()));
2318     st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2319   }
2320 }
2321 
2322 void Method::print_linkage_flags(outputStream* st) {
2323   access_flags().print_on(st);
2324   if (is_default_method()) {
2325     st->print("default ");
2326   }
2327   if (is_overpass()) {
2328     st->print("overpass ");
2329   }
2330 }
2331 #endif //PRODUCT
2332 
2333 void Method::print_value_on(outputStream* st) const {
2334   assert(is_method(), "must be method");
2335   st->print("%s", internal_name());
2336   print_address_on(st);
2337   st->print(" ");
2338   name()->print_value_on(st);
2339   st->print(" ");
2340   signature()->print_value_on(st);
2341   st->print(" in ");
2342   method_holder()->print_value_on(st);
2343   if (WizardMode) st->print("#%d", _vtable_index);
2344   if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2345   if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2346 }
2347 
2348 #if INCLUDE_SERVICES
2349 // Size Statistics
2350 void Method::collect_statistics(KlassSizeStats *sz) const {
2351   int mysize = sz->count(this);
2352   sz->_method_bytes += mysize;
2353   sz->_method_all_bytes += mysize;
2354   sz->_rw_bytes += mysize;
2355 
2356   if (constMethod()) {
2357     constMethod()->collect_statistics(sz);
2358   }
2359   if (method_data()) {
2360     method_data()->collect_statistics(sz);
2361   }
2362 }
2363 #endif // INCLUDE_SERVICES
2364 
2365 // LogTouchedMethods and PrintTouchedMethods
2366 
2367 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2368 // the Method may be garbage collected. Let's roll our own hash table.
2369 class TouchedMethodRecord : CHeapObj<mtTracing> {
2370 public:
2371   // It's OK to store Symbols here because they will NOT be GC'ed if
2372   // LogTouchedMethods is enabled.
2373   TouchedMethodRecord* _next;
2374   Symbol* _class_name;
2375   Symbol* _method_name;
2376   Symbol* _method_signature;
2377 };
2378 
2379 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2380 static TouchedMethodRecord** _touched_method_table = NULL;
2381 
2382 void Method::log_touched(TRAPS) {
2383 
2384   const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2385   Symbol* my_class = klass_name();
2386   Symbol* my_name  = name();
2387   Symbol* my_sig   = signature();
2388 
2389   unsigned int hash = my_class->identity_hash() +
2390                       my_name->identity_hash() +
2391                       my_sig->identity_hash();
2392   juint index = juint(hash) % table_size;
2393 
2394   MutexLocker ml(TouchedMethodLog_lock, THREAD);
2395   if (_touched_method_table == NULL) {
2396     _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2397                                               mtTracing, CURRENT_PC);
2398     memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2399   }
2400 
2401   TouchedMethodRecord* ptr = _touched_method_table[index];
2402   while (ptr) {
2403     if (ptr->_class_name       == my_class &&
2404         ptr->_method_name      == my_name &&
2405         ptr->_method_signature == my_sig) {
2406       return;
2407     }
2408     if (ptr->_next == NULL) break;
2409     ptr = ptr->_next;
2410   }
2411   TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2412   my_class->increment_refcount();
2413   my_name->increment_refcount();
2414   my_sig->increment_refcount();
2415   nptr->_class_name         = my_class;
2416   nptr->_method_name        = my_name;
2417   nptr->_method_signature   = my_sig;
2418   nptr->_next               = NULL;
2419 
2420   if (ptr == NULL) {
2421     // first
2422     _touched_method_table[index] = nptr;
2423   } else {
2424     ptr->_next = nptr;
2425   }
2426 }
2427 
2428 void Method::print_touched_methods(outputStream* out) {
2429   MutexLocker ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2430   out->print_cr("# Method::print_touched_methods version 1");
2431   if (_touched_method_table) {
2432     for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2433       TouchedMethodRecord* ptr = _touched_method_table[i];
2434       while(ptr) {
2435         ptr->_class_name->print_symbol_on(out);       out->print(".");
2436         ptr->_method_name->print_symbol_on(out);      out->print(":");
2437         ptr->_method_signature->print_symbol_on(out); out->cr();
2438         ptr = ptr->_next;
2439       }
2440     }
2441   }
2442 }
2443 
2444 // Verification
2445 
2446 void Method::verify_on(outputStream* st) {
2447   guarantee(is_method(), "object must be method");
2448   guarantee(constants()->is_constantPool(), "should be constant pool");
2449   MethodData* md = method_data();
2450   guarantee(md == NULL ||
2451       md->is_methodData(), "should be method data");
2452 }