1 /*
   2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/metadataOnStackMark.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "code/codeCache.hpp"
  29 #include "code/debugInfoRec.hpp"
  30 #include "gc/shared/collectedHeap.inline.hpp"
  31 #include "gc/shared/gcLocker.hpp"
  32 #include "gc/shared/generation.hpp"
  33 #include "interpreter/bytecodeStream.hpp"
  34 #include "interpreter/bytecodeTracer.hpp"
  35 #include "interpreter/bytecodes.hpp"
  36 #include "interpreter/interpreter.hpp"
  37 #include "interpreter/oopMapCache.hpp"
  38 #include "memory/heapInspection.hpp"
  39 #include "memory/metadataFactory.hpp"
  40 #include "memory/oopFactory.hpp"
  41 #include "oops/constMethod.hpp"
  42 #include "oops/method.hpp"
  43 #include "oops/methodData.hpp"
  44 #include "oops/oop.inline.hpp"
  45 #include "oops/symbol.hpp"
  46 #include "prims/jvmtiExport.hpp"
  47 #include "prims/methodHandles.hpp"
  48 #include "prims/nativeLookup.hpp"
  49 #include "runtime/arguments.hpp"
  50 #include "runtime/compilationPolicy.hpp"
  51 #include "runtime/frame.inline.hpp"
  52 #include "runtime/handles.inline.hpp"
  53 #include "runtime/orderAccess.inline.hpp"
  54 #include "runtime/relocator.hpp"
  55 #include "runtime/sharedRuntime.hpp"
  56 #include "runtime/signature.hpp"
  57 #include "utilities/quickSort.hpp"
  58 #include "utilities/xmlstream.hpp"
  59 
  60 // Implementation of Method
  61 
  62 Method* Method::allocate(ClassLoaderData* loader_data,
  63                          int byte_code_size,
  64                          AccessFlags access_flags,
  65                          InlineTableSizes* sizes,
  66                          ConstMethod::MethodType method_type,
  67                          TRAPS) {
  68   assert(!access_flags.is_native() || byte_code_size == 0,
  69          "native methods should not contain byte codes");
  70   ConstMethod* cm = ConstMethod::allocate(loader_data,
  71                                           byte_code_size,
  72                                           sizes,
  73                                           method_type,
  74                                           CHECK_NULL);
  75   int size = Method::size(access_flags.is_native());
  76   return new (loader_data, size, false, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
  77 }
  78 
  79 Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
  80   No_Safepoint_Verifier no_safepoint;
  81   set_constMethod(xconst);
  82   set_access_flags(access_flags);
  83 #ifdef CC_INTERP
  84   set_result_index(T_VOID);
  85 #endif
  86   set_intrinsic_id(vmIntrinsics::_none);
  87   set_jfr_towrite(false);
  88   set_force_inline(false);
  89   set_hidden(false);
  90   set_dont_inline(false);
  91   set_has_injected_profile(false);
  92   set_method_data(NULL);
  93   clear_method_counters();
  94   set_vtable_index(Method::garbage_vtable_index);
  95 
  96   // Fix and bury in Method*
  97   set_interpreter_entry(NULL); // sets i2i entry and from_int
  98   set_adapter_entry(NULL);
  99   clear_code(); // from_c/from_i get set to c2i/i2i
 100 
 101   if (access_flags.is_native()) {
 102     clear_native_function();
 103     set_signature_handler(NULL);
 104   }
 105 
 106   NOT_PRODUCT(set_compiled_invocation_count(0);)
 107 }
 108 
 109 // Release Method*.  The nmethod will be gone when we get here because
 110 // we've walked the code cache.
 111 void Method::deallocate_contents(ClassLoaderData* loader_data) {
 112   MetadataFactory::free_metadata(loader_data, constMethod());
 113   set_constMethod(NULL);
 114   MetadataFactory::free_metadata(loader_data, method_data());
 115   set_method_data(NULL);
 116   MetadataFactory::free_metadata(loader_data, method_counters());
 117   clear_method_counters();
 118   // The nmethod will be gone when we get here.
 119   if (code() != NULL) _code = NULL;
 120 }
 121 
 122 address Method::get_i2c_entry() {
 123   assert(_adapter != NULL, "must have");
 124   return _adapter->get_i2c_entry();
 125 }
 126 
 127 address Method::get_c2i_entry() {
 128   assert(_adapter != NULL, "must have");
 129   return _adapter->get_c2i_entry();
 130 }
 131 
 132 address Method::get_c2i_unverified_entry() {
 133   assert(_adapter != NULL, "must have");
 134   return _adapter->get_c2i_unverified_entry();
 135 }
 136 
 137 char* Method::name_and_sig_as_C_string() const {
 138   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
 139 }
 140 
 141 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
 142   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
 143 }
 144 
 145 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
 146   const char* klass_name = klass->external_name();
 147   int klass_name_len  = (int)strlen(klass_name);
 148   int method_name_len = method_name->utf8_length();
 149   int len             = klass_name_len + 1 + method_name_len + signature->utf8_length();
 150   char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);
 151   strcpy(dest, klass_name);
 152   dest[klass_name_len] = '.';
 153   strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
 154   strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
 155   dest[len] = 0;
 156   return dest;
 157 }
 158 
 159 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
 160   Symbol* klass_name = klass->name();
 161   klass_name->as_klass_external_name(buf, size);
 162   int len = (int)strlen(buf);
 163 
 164   if (len < size - 1) {
 165     buf[len++] = '.';
 166 
 167     method_name->as_C_string(&(buf[len]), size - len);
 168     len = (int)strlen(buf);
 169 
 170     signature->as_C_string(&(buf[len]), size - len);
 171   }
 172 
 173   return buf;
 174 }
 175 
 176 int Method::fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS) {
 177   // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
 178   // access exception table
 179   ExceptionTable table(mh());
 180   int length = table.length();
 181   // iterate through all entries sequentially
 182   constantPoolHandle pool(THREAD, mh->constants());
 183   for (int i = 0; i < length; i ++) {
 184     //reacquire the table in case a GC happened
 185     ExceptionTable table(mh());
 186     int beg_bci = table.start_pc(i);
 187     int end_bci = table.end_pc(i);
 188     assert(beg_bci <= end_bci, "inconsistent exception table");
 189     if (beg_bci <= throw_bci && throw_bci < end_bci) {
 190       // exception handler bci range covers throw_bci => investigate further
 191       int handler_bci = table.handler_pc(i);
 192       int klass_index = table.catch_type_index(i);
 193       if (klass_index == 0) {
 194         return handler_bci;
 195       } else if (ex_klass.is_null()) {
 196         return handler_bci;
 197       } else {
 198         // we know the exception class => get the constraint class
 199         // this may require loading of the constraint class; if verification
 200         // fails or some other exception occurs, return handler_bci
 201         Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
 202         KlassHandle klass = KlassHandle(THREAD, k);
 203         assert(klass.not_null(), "klass not loaded");
 204         if (ex_klass->is_subtype_of(klass())) {
 205           return handler_bci;
 206         }
 207       }
 208     }
 209   }
 210 
 211   return -1;
 212 }
 213 
 214 void Method::mask_for(int bci, InterpreterOopMap* mask) {
 215 
 216   Thread* myThread    = Thread::current();
 217   methodHandle h_this(myThread, this);
 218 #if defined(ASSERT) && !INCLUDE_JVMCI
 219   bool has_capability = myThread->is_VM_thread() ||
 220                         myThread->is_ConcurrentGC_thread() ||
 221                         myThread->is_GC_task_thread();
 222 
 223   if (!has_capability) {
 224     if (!VerifyStack && !VerifyLastFrame) {
 225       // verify stack calls this outside VM thread
 226       warning("oopmap should only be accessed by the "
 227               "VM, GC task or CMS threads (or during debugging)");
 228       InterpreterOopMap local_mask;
 229       method_holder()->mask_for(h_this, bci, &local_mask);
 230       local_mask.print();
 231     }
 232   }
 233 #endif
 234   method_holder()->mask_for(h_this, bci, mask);
 235   return;
 236 }
 237 
 238 
 239 int Method::bci_from(address bcp) const {
 240   if (is_native() && bcp == 0) {
 241     return 0;
 242   }
 243 #ifdef ASSERT
 244   {
 245     ResourceMark rm;
 246     assert(is_native() && bcp == code_base() || contains(bcp) || is_error_reported(),
 247            "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
 248            p2i(bcp), name_and_sig_as_C_string());
 249   }
 250 #endif
 251   return bcp - code_base();
 252 }
 253 
 254 
 255 int Method::validate_bci(int bci) const {
 256   return (bci == 0 || bci < code_size()) ? bci : -1;
 257 }
 258 
 259 // Return bci if it appears to be a valid bcp
 260 // Return -1 otherwise.
 261 // Used by profiling code, when invalid data is a possibility.
 262 // The caller is responsible for validating the Method* itself.
 263 int Method::validate_bci_from_bcp(address bcp) const {
 264   // keep bci as -1 if not a valid bci
 265   int bci = -1;
 266   if (bcp == 0 || bcp == code_base()) {
 267     // code_size() may return 0 and we allow 0 here
 268     // the method may be native
 269     bci = 0;
 270   } else if (contains(bcp)) {
 271     bci = bcp - code_base();
 272   }
 273   // Assert that if we have dodged any asserts, bci is negative.
 274   assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
 275   return bci;
 276 }
 277 
 278 address Method::bcp_from(int bci) const {
 279   assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()), "illegal bci: %d", bci);
 280   address bcp = code_base() + bci;
 281   assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
 282   return bcp;
 283 }
 284 
 285 address Method::bcp_from(address bcp) const {
 286   if (is_native() && bcp == NULL) {
 287     return code_base();
 288   } else {
 289     return bcp;
 290   }
 291 }
 292 
 293 int Method::size(bool is_native) {
 294   // If native, then include pointers for native_function and signature_handler
 295   int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
 296   int extra_words = align_size_up(extra_bytes, BytesPerWord) / BytesPerWord;
 297   return align_object_size(header_size() + extra_words);
 298 }
 299 
 300 
 301 Symbol* Method::klass_name() const {
 302   Klass* k = method_holder();
 303   assert(k->is_klass(), "must be klass");
 304   InstanceKlass* ik = (InstanceKlass*) k;
 305   return ik->name();
 306 }
 307 
 308 
 309 // Attempt to return method oop to original state.  Clear any pointers
 310 // (to objects outside the shared spaces).  We won't be able to predict
 311 // where they should point in a new JVM.  Further initialize some
 312 // entries now in order allow them to be write protected later.
 313 
 314 void Method::remove_unshareable_info() {
 315   unlink_method();
 316 }
 317 
 318 
 319 bool Method::was_executed_more_than(int n) {
 320   // Invocation counter is reset when the Method* is compiled.
 321   // If the method has compiled code we therefore assume it has
 322   // be excuted more than n times.
 323   if (is_accessor() || is_empty_method() || (code() != NULL)) {
 324     // interpreter doesn't bump invocation counter of trivial methods
 325     // compiler does not bump invocation counter of compiled methods
 326     return true;
 327   }
 328   else if ((method_counters() != NULL &&
 329             method_counters()->invocation_counter()->carry()) ||
 330            (method_data() != NULL &&
 331             method_data()->invocation_counter()->carry())) {
 332     // The carry bit is set when the counter overflows and causes
 333     // a compilation to occur.  We don't know how many times
 334     // the counter has been reset, so we simply assume it has
 335     // been executed more than n times.
 336     return true;
 337   } else {
 338     return invocation_count() > n;
 339   }
 340 }
 341 
 342 void Method::print_invocation_count() {
 343   if (is_static()) tty->print("static ");
 344   if (is_final()) tty->print("final ");
 345   if (is_synchronized()) tty->print("synchronized ");
 346   if (is_native()) tty->print("native ");
 347   tty->print("%s::", method_holder()->external_name());
 348   name()->print_symbol_on(tty);
 349   signature()->print_symbol_on(tty);
 350 
 351   if (WizardMode) {
 352     // dump the size of the byte codes
 353     tty->print(" {%d}", code_size());
 354   }
 355   tty->cr();
 356 
 357   tty->print_cr ("  interpreter_invocation_count: %8d ", interpreter_invocation_count());
 358   tty->print_cr ("  invocation_counter:           %8d ", invocation_count());
 359   tty->print_cr ("  backedge_counter:             %8d ", backedge_count());
 360 #ifndef PRODUCT
 361   if (CountCompiledCalls) {
 362     tty->print_cr ("  compiled_invocation_count: %8d ", compiled_invocation_count());
 363   }
 364 #endif
 365 }
 366 
 367 // Build a MethodData* object to hold information about this method
 368 // collected in the interpreter.
 369 void Method::build_interpreter_method_data(methodHandle method, TRAPS) {
 370   // Do not profile the method if metaspace has hit an OOM previously
 371   // allocating profiling data. Callers clear pending exception so don't
 372   // add one here.
 373   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 374     return;
 375   }
 376 
 377   // Do not profile method if current thread holds the pending list lock,
 378   // which avoids deadlock for acquiring the MethodData_lock.
 379   if (InstanceRefKlass::owns_pending_list_lock((JavaThread*)THREAD)) {
 380     return;
 381   }
 382 
 383   // Grab a lock here to prevent multiple
 384   // MethodData*s from being created.
 385   MutexLocker ml(MethodData_lock, THREAD);
 386   if (method->method_data() == NULL) {
 387     ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
 388     MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
 389     if (HAS_PENDING_EXCEPTION) {
 390       CompileBroker::log_metaspace_failure();
 391       ClassLoaderDataGraph::set_metaspace_oom(true);
 392       return;   // return the exception (which is cleared)
 393     }
 394 
 395     method->set_method_data(method_data);
 396     if (PrintMethodData && (Verbose || WizardMode)) {
 397       ResourceMark rm(THREAD);
 398       tty->print("build_interpreter_method_data for ");
 399       method->print_name(tty);
 400       tty->cr();
 401       // At the end of the run, the MDO, full of data, will be dumped.
 402     }
 403   }
 404 }
 405 
 406 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
 407   // Do not profile the method if metaspace has hit an OOM previously
 408   if (ClassLoaderDataGraph::has_metaspace_oom()) {
 409     return NULL;
 410   }
 411 
 412   methodHandle mh(m);
 413   MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
 414   if (HAS_PENDING_EXCEPTION) {
 415     CompileBroker::log_metaspace_failure();
 416     ClassLoaderDataGraph::set_metaspace_oom(true);
 417     return NULL;   // return the exception (which is cleared)
 418   }
 419   if (!mh->init_method_counters(counters)) {
 420     MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
 421   }
 422 
 423   if (LogTouchedMethods) {
 424     mh->log_touched(CHECK_NULL);
 425   }
 426 
 427   return mh->method_counters();
 428 }
 429 
 430 void Method::cleanup_inline_caches() {
 431   // The current system doesn't use inline caches in the interpreter
 432   // => nothing to do (keep this method around for future use)
 433 }
 434 
 435 
 436 int Method::extra_stack_words() {
 437   // not an inline function, to avoid a header dependency on Interpreter
 438   return extra_stack_entries() * Interpreter::stackElementSize;
 439 }
 440 
 441 
 442 void Method::compute_size_of_parameters(Thread *thread) {
 443   ArgumentSizeComputer asc(signature());
 444   set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
 445 }
 446 
 447 #ifdef CC_INTERP
 448 void Method::set_result_index(BasicType type)          {
 449   _result_index = Interpreter::BasicType_as_index(type);
 450 }
 451 #endif
 452 
 453 BasicType Method::result_type() const {
 454   ResultTypeFinder rtf(signature());
 455   return rtf.type();
 456 }
 457 
 458 
 459 bool Method::is_empty_method() const {
 460   return  code_size() == 1
 461       && *code_base() == Bytecodes::_return;
 462 }
 463 
 464 
 465 bool Method::is_vanilla_constructor() const {
 466   // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
 467   // which only calls the superclass vanilla constructor and possibly does stores of
 468   // zero constants to local fields:
 469   //
 470   //   aload_0
 471   //   invokespecial
 472   //   indexbyte1
 473   //   indexbyte2
 474   //
 475   // followed by an (optional) sequence of:
 476   //
 477   //   aload_0
 478   //   aconst_null / iconst_0 / fconst_0 / dconst_0
 479   //   putfield
 480   //   indexbyte1
 481   //   indexbyte2
 482   //
 483   // followed by:
 484   //
 485   //   return
 486 
 487   assert(name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructors");
 488   assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
 489   int size = code_size();
 490   // Check if size match
 491   if (size == 0 || size % 5 != 0) return false;
 492   address cb = code_base();
 493   int last = size - 1;
 494   if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
 495     // Does not call superclass default constructor
 496     return false;
 497   }
 498   // Check optional sequence
 499   for (int i = 4; i < last; i += 5) {
 500     if (cb[i] != Bytecodes::_aload_0) return false;
 501     if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
 502     if (cb[i+2] != Bytecodes::_putfield) return false;
 503   }
 504   return true;
 505 }
 506 
 507 
 508 bool Method::compute_has_loops_flag() {
 509   BytecodeStream bcs(this);
 510   Bytecodes::Code bc;
 511 
 512   while ((bc = bcs.next()) >= 0) {
 513     switch( bc ) {
 514       case Bytecodes::_ifeq:
 515       case Bytecodes::_ifnull:
 516       case Bytecodes::_iflt:
 517       case Bytecodes::_ifle:
 518       case Bytecodes::_ifne:
 519       case Bytecodes::_ifnonnull:
 520       case Bytecodes::_ifgt:
 521       case Bytecodes::_ifge:
 522       case Bytecodes::_if_icmpeq:
 523       case Bytecodes::_if_icmpne:
 524       case Bytecodes::_if_icmplt:
 525       case Bytecodes::_if_icmpgt:
 526       case Bytecodes::_if_icmple:
 527       case Bytecodes::_if_icmpge:
 528       case Bytecodes::_if_acmpeq:
 529       case Bytecodes::_if_acmpne:
 530       case Bytecodes::_goto:
 531       case Bytecodes::_jsr:
 532         if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
 533         break;
 534 
 535       case Bytecodes::_goto_w:
 536       case Bytecodes::_jsr_w:
 537         if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
 538         break;
 539     }
 540   }
 541   _access_flags.set_loops_flag_init();
 542   return _access_flags.has_loops();
 543 }
 544 
 545 bool Method::is_final_method(AccessFlags class_access_flags) const {
 546   // or "does_not_require_vtable_entry"
 547   // default method or overpass can occur, is not final (reuses vtable entry)
 548   // private methods get vtable entries for backward class compatibility.
 549   if (is_overpass() || is_default_method())  return false;
 550   return is_final() || class_access_flags.is_final();
 551 }
 552 
 553 bool Method::is_final_method() const {
 554   return is_final_method(method_holder()->access_flags());
 555 }
 556 
 557 bool Method::is_default_method() const {
 558   if (method_holder() != NULL &&
 559       method_holder()->is_interface() &&
 560       !is_abstract()) {
 561     return true;
 562   } else {
 563     return false;
 564   }
 565 }
 566 
 567 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
 568   if (is_final_method(class_access_flags))  return true;
 569 #ifdef ASSERT
 570   ResourceMark rm;
 571   bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
 572   if (class_access_flags.is_interface()) {
 573     assert(is_nonv == is_static(), "is_nonv=%s", name_and_sig_as_C_string());
 574   }
 575 #endif
 576   assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
 577   return vtable_index() == nonvirtual_vtable_index;
 578 }
 579 
 580 bool Method::can_be_statically_bound() const {
 581   return can_be_statically_bound(method_holder()->access_flags());
 582 }
 583 
 584 bool Method::is_accessor() const {
 585   return is_getter() || is_setter();
 586 }
 587 
 588 bool Method::is_getter() const {
 589   if (code_size() != 5) return false;
 590   if (size_of_parameters() != 1) return false;
 591   if (java_code_at(0) != Bytecodes::_aload_0)  return false;
 592   if (java_code_at(1) != Bytecodes::_getfield) return false;
 593   switch (java_code_at(4)) {
 594     case Bytecodes::_ireturn:
 595     case Bytecodes::_lreturn:
 596     case Bytecodes::_freturn:
 597     case Bytecodes::_dreturn:
 598     case Bytecodes::_areturn:
 599       break;
 600     default:
 601       return false;
 602   }
 603   return true;
 604 }
 605 
 606 bool Method::is_setter() const {
 607   if (code_size() != 6) return false;
 608   if (java_code_at(0) != Bytecodes::_aload_0) return false;
 609   switch (java_code_at(1)) {
 610     case Bytecodes::_iload_1:
 611     case Bytecodes::_aload_1:
 612     case Bytecodes::_fload_1:
 613       if (size_of_parameters() != 2) return false;
 614       break;
 615     case Bytecodes::_dload_1:
 616     case Bytecodes::_lload_1:
 617       if (size_of_parameters() != 3) return false;
 618       break;
 619     default:
 620       return false;
 621   }
 622   if (java_code_at(2) != Bytecodes::_putfield) return false;
 623   if (java_code_at(5) != Bytecodes::_return)   return false;
 624   return true;
 625 }
 626 
 627 bool Method::is_constant_getter() const {
 628   int last_index = code_size() - 1;
 629   // Check if the first 1-3 bytecodes are a constant push
 630   // and the last bytecode is a return.
 631   return (2 <= code_size() && code_size() <= 4 &&
 632           Bytecodes::is_const(java_code_at(0)) &&
 633           Bytecodes::length_for(java_code_at(0)) == last_index &&
 634           Bytecodes::is_return(java_code_at(last_index)));
 635 }
 636 
 637 bool Method::is_initializer() const {
 638   return name() == vmSymbols::object_initializer_name() || is_static_initializer();
 639 }
 640 
 641 bool Method::has_valid_initializer_flags() const {
 642   return (is_static() ||
 643           method_holder()->major_version() < 51);
 644 }
 645 
 646 bool Method::is_static_initializer() const {
 647   // For classfiles version 51 or greater, ensure that the clinit method is
 648   // static.  Non-static methods with the name "<clinit>" are not static
 649   // initializers. (older classfiles exempted for backward compatibility)
 650   return name() == vmSymbols::class_initializer_name() &&
 651          has_valid_initializer_flags();
 652 }
 653 
 654 
 655 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
 656   int length = method->checked_exceptions_length();
 657   if (length == 0) {  // common case
 658     return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
 659   } else {
 660     methodHandle h_this(THREAD, method);
 661     objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
 662     objArrayHandle mirrors (THREAD, m_oop);
 663     for (int i = 0; i < length; i++) {
 664       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
 665       Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
 666       assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
 667       mirrors->obj_at_put(i, k->java_mirror());
 668     }
 669     return mirrors;
 670   }
 671 };
 672 
 673 
 674 int Method::line_number_from_bci(int bci) const {
 675   if (bci == SynchronizationEntryBCI) bci = 0;
 676   assert(bci == 0 || 0 <= bci && bci < code_size(), "illegal bci");
 677   int best_bci  =  0;
 678   int best_line = -1;
 679 
 680   if (has_linenumber_table()) {
 681     // The line numbers are a short array of 2-tuples [start_pc, line_number].
 682     // Not necessarily sorted and not necessarily one-to-one.
 683     CompressedLineNumberReadStream stream(compressed_linenumber_table());
 684     while (stream.read_pair()) {
 685       if (stream.bci() == bci) {
 686         // perfect match
 687         return stream.line();
 688       } else {
 689         // update best_bci/line
 690         if (stream.bci() < bci && stream.bci() >= best_bci) {
 691           best_bci  = stream.bci();
 692           best_line = stream.line();
 693         }
 694       }
 695     }
 696   }
 697   return best_line;
 698 }
 699 
 700 
 701 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
 702   if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
 703     Thread *thread = Thread::current();
 704     Symbol* klass_name = constants()->klass_name_at(klass_index);
 705     Handle loader(thread, method_holder()->class_loader());
 706     Handle prot  (thread, method_holder()->protection_domain());
 707     return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
 708   } else {
 709     return true;
 710   }
 711 }
 712 
 713 
 714 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
 715   int klass_index = constants()->klass_ref_index_at(refinfo_index);
 716   if (must_be_resolved) {
 717     // Make sure klass is resolved in constantpool.
 718     if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
 719   }
 720   return is_klass_loaded_by_klass_index(klass_index);
 721 }
 722 
 723 
 724 void Method::set_native_function(address function, bool post_event_flag) {
 725   assert(function != NULL, "use clear_native_function to unregister natives");
 726   assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
 727   address* native_function = native_function_addr();
 728 
 729   // We can see racers trying to place the same native function into place. Once
 730   // is plenty.
 731   address current = *native_function;
 732   if (current == function) return;
 733   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
 734       function != NULL) {
 735     // native_method_throw_unsatisfied_link_error_entry() should only
 736     // be passed when post_event_flag is false.
 737     assert(function !=
 738       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 739       "post_event_flag mis-match");
 740 
 741     // post the bind event, and possible change the bind function
 742     JvmtiExport::post_native_method_bind(this, &function);
 743   }
 744   *native_function = function;
 745   // This function can be called more than once. We must make sure that we always
 746   // use the latest registered method -> check if a stub already has been generated.
 747   // If so, we have to make it not_entrant.
 748   nmethod* nm = code(); // Put it into local variable to guard against concurrent updates
 749   if (nm != NULL) {
 750     nm->make_not_entrant();
 751   }
 752 }
 753 
 754 
 755 bool Method::has_native_function() const {
 756   if (is_method_handle_intrinsic())
 757     return false;  // special-cased in SharedRuntime::generate_native_wrapper
 758   address func = native_function();
 759   return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
 760 }
 761 
 762 
 763 void Method::clear_native_function() {
 764   // Note: is_method_handle_intrinsic() is allowed here.
 765   set_native_function(
 766     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 767     !native_bind_event_is_interesting);
 768   clear_code();
 769 }
 770 
 771 address Method::critical_native_function() {
 772   methodHandle mh(this);
 773   return NativeLookup::lookup_critical_entry(mh);
 774 }
 775 
 776 
 777 void Method::set_signature_handler(address handler) {
 778   address* signature_handler =  signature_handler_addr();
 779   *signature_handler = handler;
 780 }
 781 
 782 
 783 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
 784   if (PrintCompilation && report) {
 785     ttyLocker ttyl;
 786     tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
 787     if (comp_level == CompLevel_all) {
 788       tty->print("all levels ");
 789     } else {
 790       tty->print("levels ");
 791       for (int i = (int)CompLevel_none; i <= comp_level; i++) {
 792         tty->print("%d ", i);
 793       }
 794     }
 795     this->print_short_name(tty);
 796     int size = this->code_size();
 797     if (size > 0) {
 798       tty->print(" (%d bytes)", size);
 799     }
 800     if (reason != NULL) {
 801       tty->print("   %s", reason);
 802     }
 803     tty->cr();
 804   }
 805   if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
 806     ttyLocker ttyl;
 807     xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
 808                      os::current_thread_id(), is_osr, comp_level);
 809     if (reason != NULL) {
 810       xtty->print(" reason=\'%s\'", reason);
 811     }
 812     xtty->method(this);
 813     xtty->stamp();
 814     xtty->end_elem();
 815   }
 816 }
 817 
 818 bool Method::is_always_compilable() const {
 819   // Generated adapters must be compiled
 820   if (is_method_handle_intrinsic() && is_synthetic()) {
 821     assert(!is_not_c1_compilable(), "sanity check");
 822     assert(!is_not_c2_compilable(), "sanity check");
 823     return true;
 824   }
 825 
 826   return false;
 827 }
 828 
 829 bool Method::is_not_compilable(int comp_level) const {
 830   if (number_of_breakpoints() > 0)
 831     return true;
 832   if (is_always_compilable())
 833     return false;
 834   if (comp_level == CompLevel_any)
 835     return is_not_c1_compilable() || is_not_c2_compilable();
 836   if (is_c1_compile(comp_level))
 837     return is_not_c1_compilable();
 838   if (is_c2_compile(comp_level))
 839     return is_not_c2_compilable();
 840   return false;
 841 }
 842 
 843 // call this when compiler finds that this method is not compilable
 844 void Method::set_not_compilable(int comp_level, bool report, const char* reason) {
 845   if (is_always_compilable()) {
 846     // Don't mark a method which should be always compilable
 847     return;
 848   }
 849   print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
 850   if (comp_level == CompLevel_all) {
 851     set_not_c1_compilable();
 852     set_not_c2_compilable();
 853   } else {
 854     if (is_c1_compile(comp_level))
 855       set_not_c1_compilable();
 856     if (is_c2_compile(comp_level))
 857       set_not_c2_compilable();
 858   }
 859   CompilationPolicy::policy()->disable_compilation(this);
 860   assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
 861 }
 862 
 863 bool Method::is_not_osr_compilable(int comp_level) const {
 864   if (is_not_compilable(comp_level))
 865     return true;
 866   if (comp_level == CompLevel_any)
 867     return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
 868   if (is_c1_compile(comp_level))
 869     return is_not_c1_osr_compilable();
 870   if (is_c2_compile(comp_level))
 871     return is_not_c2_osr_compilable();
 872   return false;
 873 }
 874 
 875 void Method::set_not_osr_compilable(int comp_level, bool report, const char* reason) {
 876   print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
 877   if (comp_level == CompLevel_all) {
 878     set_not_c1_osr_compilable();
 879     set_not_c2_osr_compilable();
 880   } else {
 881     if (is_c1_compile(comp_level))
 882       set_not_c1_osr_compilable();
 883     if (is_c2_compile(comp_level))
 884       set_not_c2_osr_compilable();
 885   }
 886   CompilationPolicy::policy()->disable_compilation(this);
 887   assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
 888 }
 889 
 890 // Revert to using the interpreter and clear out the nmethod
 891 void Method::clear_code() {
 892 
 893   // this may be NULL if c2i adapters have not been made yet
 894   // Only should happen at allocate time.
 895   if (_adapter == NULL) {
 896     _from_compiled_entry    = NULL;
 897   } else {
 898     _from_compiled_entry    = _adapter->get_c2i_entry();
 899   }
 900   OrderAccess::storestore();
 901   _from_interpreted_entry = _i2i_entry;
 902   OrderAccess::storestore();
 903   _code = NULL;
 904 }
 905 
 906 // Called by class data sharing to remove any entry points (which are not shared)
 907 void Method::unlink_method() {
 908   _code = NULL;
 909   _i2i_entry = NULL;
 910   _from_interpreted_entry = NULL;
 911   if (is_native()) {
 912     *native_function_addr() = NULL;
 913     set_signature_handler(NULL);
 914   }
 915   NOT_PRODUCT(set_compiled_invocation_count(0);)
 916   _adapter = NULL;
 917   _from_compiled_entry = NULL;
 918 
 919   // In case of DumpSharedSpaces, _method_data should always be NULL.
 920   //
 921   // During runtime (!DumpSharedSpaces), when we are cleaning a
 922   // shared class that failed to load, this->link_method() may
 923   // have already been called (before an exception happened), so
 924   // this->_method_data may not be NULL.
 925   assert(!DumpSharedSpaces || _method_data == NULL, "unexpected method data?");
 926 
 927   set_method_data(NULL);
 928   clear_method_counters();
 929 }
 930 
 931 // Called when the method_holder is getting linked. Setup entrypoints so the method
 932 // is ready to be called from interpreter, compiler, and vtables.
 933 void Method::link_method(methodHandle h_method, TRAPS) {
 934   // If the code cache is full, we may reenter this function for the
 935   // leftover methods that weren't linked.
 936   if (_i2i_entry != NULL) return;
 937 
 938   assert(_adapter == NULL, "init'd to NULL" );
 939   assert( _code == NULL, "nothing compiled yet" );
 940 
 941   // Setup interpreter entrypoint
 942   assert(this == h_method(), "wrong h_method()" );
 943   address entry = Interpreter::entry_for_method(h_method);
 944   assert(entry != NULL, "interpreter entry must be non-null");
 945   // Sets both _i2i_entry and _from_interpreted_entry
 946   set_interpreter_entry(entry);
 947 
 948   // Don't overwrite already registered native entries.
 949   if (is_native() && !has_native_function()) {
 950     set_native_function(
 951       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 952       !native_bind_event_is_interesting);
 953   }
 954 
 955   // Setup compiler entrypoint.  This is made eagerly, so we do not need
 956   // special handling of vtables.  An alternative is to make adapters more
 957   // lazily by calling make_adapter() from from_compiled_entry() for the
 958   // normal calls.  For vtable calls life gets more complicated.  When a
 959   // call-site goes mega-morphic we need adapters in all methods which can be
 960   // called from the vtable.  We need adapters on such methods that get loaded
 961   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
 962   // problem we'll make these lazily later.
 963   (void) make_adapters(h_method, CHECK);
 964 
 965   // ONLY USE the h_method now as make_adapter may have blocked
 966 
 967 }
 968 
 969 address Method::make_adapters(methodHandle mh, TRAPS) {
 970   // Adapters for compiled code are made eagerly here.  They are fairly
 971   // small (generally < 100 bytes) and quick to make (and cached and shared)
 972   // so making them eagerly shouldn't be too expensive.
 973   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
 974   if (adapter == NULL ) {
 975     THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
 976   }
 977 
 978   mh->set_adapter_entry(adapter);
 979   mh->_from_compiled_entry = adapter->get_c2i_entry();
 980   return adapter->get_c2i_entry();
 981 }
 982 
 983 void Method::restore_unshareable_info(TRAPS) {
 984   // Since restore_unshareable_info can be called more than once for a method, don't
 985   // redo any work.   If this field is restored, there is nothing to do.
 986   if (_from_compiled_entry == NULL) {
 987     // restore method's vtable by calling a virtual function
 988     restore_vtable();
 989 
 990     methodHandle mh(THREAD, this);
 991     link_method(mh, CHECK);
 992   }
 993 }
 994 
 995 
 996 // The verified_code_entry() must be called when a invoke is resolved
 997 // on this method.
 998 
 999 // It returns the compiled code entry point, after asserting not null.
1000 // This function is called after potential safepoints so that nmethod
1001 // or adapter that it points to is still live and valid.
1002 // This function must not hit a safepoint!
1003 address Method::verified_code_entry() {
1004   debug_only(No_Safepoint_Verifier nsv;)
1005   assert(_from_compiled_entry != NULL, "must be set");
1006   return _from_compiled_entry;
1007 }
1008 
1009 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1010 // (could be racing a deopt).
1011 // Not inline to avoid circular ref.
1012 bool Method::check_code() const {
1013   // cached in a register or local.  There's a race on the value of the field.
1014   nmethod *code = (nmethod *)OrderAccess::load_ptr_acquire(&_code);
1015   return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
1016 }
1017 
1018 // Install compiled code.  Instantly it can execute.
1019 void Method::set_code(methodHandle mh, nmethod *code) {
1020   assert( code, "use clear_code to remove code" );
1021   assert( mh->check_code(), "" );
1022 
1023   guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
1024 
1025   // These writes must happen in this order, because the interpreter will
1026   // directly jump to from_interpreted_entry which jumps to an i2c adapter
1027   // which jumps to _from_compiled_entry.
1028   mh->_code = code;             // Assign before allowing compiled code to exec
1029 
1030   int comp_level = code->comp_level();
1031   // In theory there could be a race here. In practice it is unlikely
1032   // and not worth worrying about.
1033   if (comp_level > mh->highest_comp_level()) {
1034     mh->set_highest_comp_level(comp_level);
1035   }
1036 
1037   OrderAccess::storestore();
1038 #ifdef SHARK
1039   mh->_from_interpreted_entry = code->insts_begin();
1040 #else //!SHARK
1041   mh->_from_compiled_entry = code->verified_entry_point();
1042   OrderAccess::storestore();
1043   // Instantly compiled code can execute.
1044   if (!mh->is_method_handle_intrinsic())
1045     mh->_from_interpreted_entry = mh->get_i2c_entry();
1046 #endif //!SHARK
1047 }
1048 
1049 
1050 bool Method::is_overridden_in(Klass* k) const {
1051   InstanceKlass* ik = InstanceKlass::cast(k);
1052 
1053   if (ik->is_interface()) return false;
1054 
1055   // If method is an interface, we skip it - except if it
1056   // is a miranda method
1057   if (method_holder()->is_interface()) {
1058     // Check that method is not a miranda method
1059     if (ik->lookup_method(name(), signature()) == NULL) {
1060       // No implementation exist - so miranda method
1061       return false;
1062     }
1063     return true;
1064   }
1065 
1066   assert(ik->is_subclass_of(method_holder()), "should be subklass");
1067   assert(ik->vtable() != NULL, "vtable should exist");
1068   if (!has_vtable_index()) {
1069     return false;
1070   } else {
1071     Method* vt_m = ik->method_at_vtable(vtable_index());
1072     return vt_m != this;
1073   }
1074 }
1075 
1076 
1077 // give advice about whether this Method* should be cached or not
1078 bool Method::should_not_be_cached() const {
1079   if (is_old()) {
1080     // This method has been redefined. It is either EMCP or obsolete
1081     // and we don't want to cache it because that would pin the method
1082     // down and prevent it from being collectible if and when it
1083     // finishes executing.
1084     return true;
1085   }
1086 
1087   // caching this method should be just fine
1088   return false;
1089 }
1090 
1091 
1092 /**
1093  *  Returns true if this is one of the specially treated methods for
1094  *  security related stack walks (like Reflection.getCallerClass).
1095  */
1096 bool Method::is_ignored_by_security_stack_walk() const {
1097   if (intrinsic_id() == vmIntrinsics::_invoke) {
1098     // This is Method.invoke() -- ignore it
1099     return true;
1100   }
1101   if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1102     // This is an auxilary frame -- ignore it
1103     return true;
1104   }
1105   if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1106     // This is an internal adapter frame for method handles -- ignore it
1107     return true;
1108   }
1109   return false;
1110 }
1111 
1112 
1113 // Constant pool structure for invoke methods:
1114 enum {
1115   _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.
1116   _imcp_invoke_signature,       // utf8: (variable Symbol*)
1117   _imcp_limit
1118 };
1119 
1120 // Test if this method is an MH adapter frame generated by Java code.
1121 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1122 bool Method::is_compiled_lambda_form() const {
1123   return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1124 }
1125 
1126 // Test if this method is an internal MH primitive method.
1127 bool Method::is_method_handle_intrinsic() const {
1128   vmIntrinsics::ID iid = intrinsic_id();
1129   return (MethodHandles::is_signature_polymorphic(iid) &&
1130           MethodHandles::is_signature_polymorphic_intrinsic(iid));
1131 }
1132 
1133 bool Method::has_member_arg() const {
1134   vmIntrinsics::ID iid = intrinsic_id();
1135   return (MethodHandles::is_signature_polymorphic(iid) &&
1136           MethodHandles::has_member_arg(iid));
1137 }
1138 
1139 // Make an instance of a signature-polymorphic internal MH primitive.
1140 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1141                                                          Symbol* signature,
1142                                                          TRAPS) {
1143   ResourceMark rm;
1144   methodHandle empty;
1145 
1146   KlassHandle holder = SystemDictionary::MethodHandle_klass();
1147   Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1148   assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1149   if (TraceMethodHandles) {
1150     tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1151   }
1152 
1153   // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1154   name->increment_refcount();
1155   signature->increment_refcount();
1156 
1157   int cp_length = _imcp_limit;
1158   ClassLoaderData* loader_data = holder->class_loader_data();
1159   constantPoolHandle cp;
1160   {
1161     ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1162     cp = constantPoolHandle(THREAD, cp_oop);
1163   }
1164   cp->set_pool_holder(InstanceKlass::cast(holder()));
1165   cp->symbol_at_put(_imcp_invoke_name,       name);
1166   cp->symbol_at_put(_imcp_invoke_signature,  signature);
1167   cp->set_has_preresolution();
1168 
1169   // decide on access bits:  public or not?
1170   int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1171   bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1172   if (must_be_static)  flags_bits |= JVM_ACC_STATIC;
1173   assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1174 
1175   methodHandle m;
1176   {
1177     InlineTableSizes sizes;
1178     Method* m_oop = Method::allocate(loader_data, 0,
1179                                      accessFlags_from(flags_bits), &sizes,
1180                                      ConstMethod::NORMAL, CHECK_(empty));
1181     m = methodHandle(THREAD, m_oop);
1182   }
1183   m->set_constants(cp());
1184   m->set_name_index(_imcp_invoke_name);
1185   m->set_signature_index(_imcp_invoke_signature);
1186   assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1187   assert(m->signature() == signature, "");
1188 #ifdef CC_INTERP
1189   ResultTypeFinder rtf(signature);
1190   m->set_result_index(rtf.type());
1191 #endif
1192   m->compute_size_of_parameters(THREAD);
1193   m->init_intrinsic_id();
1194   assert(m->is_method_handle_intrinsic(), "");
1195 #ifdef ASSERT
1196   if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();
1197   assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1198   assert(m->intrinsic_id() == iid, "correctly predicted iid");
1199 #endif //ASSERT
1200 
1201   // Finally, set up its entry points.
1202   assert(m->can_be_statically_bound(), "");
1203   m->set_vtable_index(Method::nonvirtual_vtable_index);
1204   m->link_method(m, CHECK_(empty));
1205 
1206   if (TraceMethodHandles && (Verbose || WizardMode))
1207     m->print_on(tty);
1208 
1209   return m;
1210 }
1211 
1212 Klass* Method::check_non_bcp_klass(Klass* klass) {
1213   if (klass != NULL && klass->class_loader() != NULL) {
1214     if (klass->oop_is_objArray())
1215       klass = ObjArrayKlass::cast(klass)->bottom_klass();
1216     return klass;
1217   }
1218   return NULL;
1219 }
1220 
1221 
1222 methodHandle Method::clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
1223                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1224   // Code below does not work for native methods - they should never get rewritten anyway
1225   assert(!m->is_native(), "cannot rewrite native methods");
1226   // Allocate new Method*
1227   AccessFlags flags = m->access_flags();
1228 
1229   ConstMethod* cm = m->constMethod();
1230   int checked_exceptions_len = cm->checked_exceptions_length();
1231   int localvariable_len = cm->localvariable_table_length();
1232   int exception_table_len = cm->exception_table_length();
1233   int method_parameters_len = cm->method_parameters_length();
1234   int method_annotations_len = cm->method_annotations_length();
1235   int parameter_annotations_len = cm->parameter_annotations_length();
1236   int type_annotations_len = cm->type_annotations_length();
1237   int default_annotations_len = cm->default_annotations_length();
1238 
1239   InlineTableSizes sizes(
1240       localvariable_len,
1241       new_compressed_linenumber_size,
1242       exception_table_len,
1243       checked_exceptions_len,
1244       method_parameters_len,
1245       cm->generic_signature_index(),
1246       method_annotations_len,
1247       parameter_annotations_len,
1248       type_annotations_len,
1249       default_annotations_len,
1250       0);
1251 
1252   ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1253   Method* newm_oop = Method::allocate(loader_data,
1254                                       new_code_length,
1255                                       flags,
1256                                       &sizes,
1257                                       m->method_type(),
1258                                       CHECK_(methodHandle()));
1259   methodHandle newm (THREAD, newm_oop);
1260 
1261   // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1262   ConstMethod* newcm = newm->constMethod();
1263   int new_const_method_size = newm->constMethod()->size();
1264 
1265   memcpy(newm(), m(), sizeof(Method));
1266 
1267   // Create shallow copy of ConstMethod.
1268   memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1269 
1270   // Reset correct method/const method, method size, and parameter info
1271   newm->set_constMethod(newcm);
1272   newm->constMethod()->set_code_size(new_code_length);
1273   newm->constMethod()->set_constMethod_size(new_const_method_size);
1274   assert(newm->code_size() == new_code_length, "check");
1275   assert(newm->method_parameters_length() == method_parameters_len, "check");
1276   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1277   assert(newm->exception_table_length() == exception_table_len, "check");
1278   assert(newm->localvariable_table_length() == localvariable_len, "check");
1279   // Copy new byte codes
1280   memcpy(newm->code_base(), new_code, new_code_length);
1281   // Copy line number table
1282   if (new_compressed_linenumber_size > 0) {
1283     memcpy(newm->compressed_linenumber_table(),
1284            new_compressed_linenumber_table,
1285            new_compressed_linenumber_size);
1286   }
1287   // Copy method_parameters
1288   if (method_parameters_len > 0) {
1289     memcpy(newm->method_parameters_start(),
1290            m->method_parameters_start(),
1291            method_parameters_len * sizeof(MethodParametersElement));
1292   }
1293   // Copy checked_exceptions
1294   if (checked_exceptions_len > 0) {
1295     memcpy(newm->checked_exceptions_start(),
1296            m->checked_exceptions_start(),
1297            checked_exceptions_len * sizeof(CheckedExceptionElement));
1298   }
1299   // Copy exception table
1300   if (exception_table_len > 0) {
1301     memcpy(newm->exception_table_start(),
1302            m->exception_table_start(),
1303            exception_table_len * sizeof(ExceptionTableElement));
1304   }
1305   // Copy local variable number table
1306   if (localvariable_len > 0) {
1307     memcpy(newm->localvariable_table_start(),
1308            m->localvariable_table_start(),
1309            localvariable_len * sizeof(LocalVariableTableElement));
1310   }
1311   // Copy stackmap table
1312   if (m->has_stackmap_table()) {
1313     int code_attribute_length = m->stackmap_data()->length();
1314     Array<u1>* stackmap_data =
1315       MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1316     memcpy((void*)stackmap_data->adr_at(0),
1317            (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1318     newm->set_stackmap_data(stackmap_data);
1319   }
1320 
1321   // copy annotations over to new method
1322   newcm->copy_annotations_from(cm);
1323   return newm;
1324 }
1325 
1326 vmSymbols::SID Method::klass_id_for_intrinsics(Klass* holder) {
1327   // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1328   // because we are not loading from core libraries
1329   // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1330   // which does not use the class default class loader so we check for its loader here
1331   InstanceKlass* ik = InstanceKlass::cast(holder);
1332   if ((ik->class_loader() != NULL) && !SystemDictionary::is_ext_class_loader(ik->class_loader())) {
1333     return vmSymbols::NO_SID;   // regardless of name, no intrinsics here
1334   }
1335 
1336   // see if the klass name is well-known:
1337   Symbol* klass_name = ik->name();
1338   return vmSymbols::find_sid(klass_name);
1339 }
1340 
1341 void Method::init_intrinsic_id() {
1342   assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1343   const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1344   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1345   assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1346 
1347   // the klass name is well-known:
1348   vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1349   assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1350 
1351   // ditto for method and signature:
1352   vmSymbols::SID  name_id = vmSymbols::find_sid(name());
1353   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1354       && name_id == vmSymbols::NO_SID)
1355     return;
1356   vmSymbols::SID   sig_id = vmSymbols::find_sid(signature());
1357   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1358       && sig_id == vmSymbols::NO_SID)  return;
1359   jshort flags = access_flags().as_short();
1360 
1361   vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1362   if (id != vmIntrinsics::_none) {
1363     set_intrinsic_id(id);
1364     if (id == vmIntrinsics::_Class_cast) {
1365       // Even if the intrinsic is rejected, we want to inline this simple method.
1366       set_force_inline(true);
1367     }
1368     return;
1369   }
1370 
1371   // A few slightly irregular cases:
1372   switch (klass_id) {
1373   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1374     // Second chance: check in regular Math.
1375     switch (name_id) {
1376     case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1377     case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1378     case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1379       // pretend it is the corresponding method in the non-strict class:
1380       klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1381       id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1382       break;
1383     }
1384     break;
1385 
1386   // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*.
1387   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1388     if (!is_native())  break;
1389     id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1390     if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1391       id = vmIntrinsics::_none;
1392     break;
1393   }
1394 
1395   if (id != vmIntrinsics::_none) {
1396     // Set up its iid.  It is an alias method.
1397     set_intrinsic_id(id);
1398     return;
1399   }
1400 }
1401 
1402 // These two methods are static since a GC may move the Method
1403 bool Method::load_signature_classes(methodHandle m, TRAPS) {
1404   if (!THREAD->can_call_java()) {
1405     // There is nothing useful this routine can do from within the Compile thread.
1406     // Hopefully, the signature contains only well-known classes.
1407     // We could scan for this and return true/false, but the caller won't care.
1408     return false;
1409   }
1410   bool sig_is_loaded = true;
1411   Handle class_loader(THREAD, m->method_holder()->class_loader());
1412   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1413   ResourceMark rm(THREAD);
1414   Symbol*  signature = m->signature();
1415   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1416     if (ss.is_object()) {
1417       Symbol* sym = ss.as_symbol(CHECK_(false));
1418       Symbol*  name  = sym;
1419       Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1420                                              protection_domain, THREAD);
1421       // We are loading classes eagerly. If a ClassNotFoundException or
1422       // a LinkageError was generated, be sure to ignore it.
1423       if (HAS_PENDING_EXCEPTION) {
1424         if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1425             PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1426           CLEAR_PENDING_EXCEPTION;
1427         } else {
1428           return false;
1429         }
1430       }
1431       if( klass == NULL) { sig_is_loaded = false; }
1432     }
1433   }
1434   return sig_is_loaded;
1435 }
1436 
1437 bool Method::has_unloaded_classes_in_signature(methodHandle m, TRAPS) {
1438   Handle class_loader(THREAD, m->method_holder()->class_loader());
1439   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1440   ResourceMark rm(THREAD);
1441   Symbol*  signature = m->signature();
1442   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1443     if (ss.type() == T_OBJECT) {
1444       Symbol* name = ss.as_symbol_or_null();
1445       if (name == NULL) return true;
1446       Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1447       if (klass == NULL) return true;
1448     }
1449   }
1450   return false;
1451 }
1452 
1453 // Exposed so field engineers can debug VM
1454 void Method::print_short_name(outputStream* st) {
1455   ResourceMark rm;
1456 #ifdef PRODUCT
1457   st->print(" %s::", method_holder()->external_name());
1458 #else
1459   st->print(" %s::", method_holder()->internal_name());
1460 #endif
1461   name()->print_symbol_on(st);
1462   if (WizardMode) signature()->print_symbol_on(st);
1463   else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1464     MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1465 }
1466 
1467 // Comparer for sorting an object array containing
1468 // Method*s.
1469 static int method_comparator(Method* a, Method* b) {
1470   return a->name()->fast_compare(b->name());
1471 }
1472 
1473 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1474 // default_methods also uses this without the ordering for fast find_method
1475 void Method::sort_methods(Array<Method*>* methods, bool idempotent, bool set_idnums) {
1476   int length = methods->length();
1477   if (length > 1) {
1478     {
1479       No_Safepoint_Verifier nsv;
1480       QuickSort::sort<Method*>(methods->data(), length, method_comparator, idempotent);
1481     }
1482     // Reset method ordering
1483     if (set_idnums) {
1484       for (int i = 0; i < length; i++) {
1485         Method* m = methods->at(i);
1486         m->set_method_idnum(i);
1487         m->set_orig_method_idnum(i);
1488       }
1489     }
1490   }
1491 }
1492 
1493 //-----------------------------------------------------------------------------------
1494 // Non-product code unless JVM/TI needs it
1495 
1496 #if !defined(PRODUCT) || INCLUDE_JVMTI
1497 class SignatureTypePrinter : public SignatureTypeNames {
1498  private:
1499   outputStream* _st;
1500   bool _use_separator;
1501 
1502   void type_name(const char* name) {
1503     if (_use_separator) _st->print(", ");
1504     _st->print("%s", name);
1505     _use_separator = true;
1506   }
1507 
1508  public:
1509   SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1510     _st = st;
1511     _use_separator = false;
1512   }
1513 
1514   void print_parameters()              { _use_separator = false; iterate_parameters(); }
1515   void print_returntype()              { _use_separator = false; iterate_returntype(); }
1516 };
1517 
1518 
1519 void Method::print_name(outputStream* st) {
1520   Thread *thread = Thread::current();
1521   ResourceMark rm(thread);
1522   st->print("%s ", is_static() ? "static" : "virtual");
1523   if (WizardMode) {
1524     st->print("%s.", method_holder()->internal_name());
1525     name()->print_symbol_on(st);
1526     signature()->print_symbol_on(st);
1527   } else {
1528     SignatureTypePrinter sig(signature(), st);
1529     sig.print_returntype();
1530     st->print(" %s.", method_holder()->internal_name());
1531     name()->print_symbol_on(st);
1532     st->print("(");
1533     sig.print_parameters();
1534     st->print(")");
1535   }
1536 }
1537 #endif // !PRODUCT || INCLUDE_JVMTI
1538 
1539 
1540 void Method::print_codes_on(outputStream* st) const {
1541   print_codes_on(0, code_size(), st);
1542 }
1543 
1544 void Method::print_codes_on(int from, int to, outputStream* st) const {
1545   Thread *thread = Thread::current();
1546   ResourceMark rm(thread);
1547   methodHandle mh (thread, (Method*)this);
1548   BytecodeStream s(mh);
1549   s.set_interval(from, to);
1550   BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1551   while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1552 }
1553 
1554 
1555 // Simple compression of line number tables. We use a regular compressed stream, except that we compress deltas
1556 // between (bci,line) pairs since they are smaller. If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
1557 // we save it as one byte, otherwise we write a 0xFF escape character and use regular compression. 0x0 is used
1558 // as end-of-stream terminator.
1559 
1560 void CompressedLineNumberWriteStream::write_pair_regular(int bci_delta, int line_delta) {
1561   // bci and line number does not compress into single byte.
1562   // Write out escape character and use regular compression for bci and line number.
1563   write_byte((jubyte)0xFF);
1564   write_signed_int(bci_delta);
1565   write_signed_int(line_delta);
1566 }
1567 
1568 // See comment in method.hpp which explains why this exists.
1569 #if defined(_M_AMD64) && _MSC_VER >= 1400
1570 #pragma optimize("", off)
1571 void CompressedLineNumberWriteStream::write_pair(int bci, int line) {
1572   write_pair_inline(bci, line);
1573 }
1574 #pragma optimize("", on)
1575 #endif
1576 
1577 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1578   _bci = 0;
1579   _line = 0;
1580 };
1581 
1582 
1583 bool CompressedLineNumberReadStream::read_pair() {
1584   jubyte next = read_byte();
1585   // Check for terminator
1586   if (next == 0) return false;
1587   if (next == 0xFF) {
1588     // Escape character, regular compression used
1589     _bci  += read_signed_int();
1590     _line += read_signed_int();
1591   } else {
1592     // Single byte compression used
1593     _bci  += next >> 3;
1594     _line += next & 0x7;
1595   }
1596   return true;
1597 }
1598 
1599 
1600 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1601   BreakpointInfo* bp = method_holder()->breakpoints();
1602   for (; bp != NULL; bp = bp->next()) {
1603     if (bp->match(this, bci)) {
1604       return bp->orig_bytecode();
1605     }
1606   }
1607   {
1608     ResourceMark rm;
1609     fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1610   }
1611   return Bytecodes::_shouldnotreachhere;
1612 }
1613 
1614 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1615   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1616   BreakpointInfo* bp = method_holder()->breakpoints();
1617   for (; bp != NULL; bp = bp->next()) {
1618     if (bp->match(this, bci)) {
1619       bp->set_orig_bytecode(code);
1620       // and continue, in case there is more than one
1621     }
1622   }
1623 }
1624 
1625 void Method::set_breakpoint(int bci) {
1626   InstanceKlass* ik = method_holder();
1627   BreakpointInfo *bp = new BreakpointInfo(this, bci);
1628   bp->set_next(ik->breakpoints());
1629   ik->set_breakpoints(bp);
1630   // do this last:
1631   bp->set(this);
1632 }
1633 
1634 static void clear_matches(Method* m, int bci) {
1635   InstanceKlass* ik = m->method_holder();
1636   BreakpointInfo* prev_bp = NULL;
1637   BreakpointInfo* next_bp;
1638   for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1639     next_bp = bp->next();
1640     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1641     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1642       // do this first:
1643       bp->clear(m);
1644       // unhook it
1645       if (prev_bp != NULL)
1646         prev_bp->set_next(next_bp);
1647       else
1648         ik->set_breakpoints(next_bp);
1649       delete bp;
1650       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1651       // at same location. So we have multiple matching (method_index and bci)
1652       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1653       // breakpoint for clear_breakpoint request and keep all other method versions
1654       // BreakpointInfo for future clear_breakpoint request.
1655       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1656       // which is being called when class is unloaded. We delete all the Breakpoint
1657       // information for all versions of method. We may not correctly restore the original
1658       // bytecode in all method versions, but that is ok. Because the class is being unloaded
1659       // so these methods won't be used anymore.
1660       if (bci >= 0) {
1661         break;
1662       }
1663     } else {
1664       // This one is a keeper.
1665       prev_bp = bp;
1666     }
1667   }
1668 }
1669 
1670 void Method::clear_breakpoint(int bci) {
1671   assert(bci >= 0, "");
1672   clear_matches(this, bci);
1673 }
1674 
1675 void Method::clear_all_breakpoints() {
1676   clear_matches(this, -1);
1677 }
1678 
1679 
1680 int Method::invocation_count() {
1681   MethodCounters *mcs = method_counters();
1682   if (TieredCompilation) {
1683     MethodData* const mdo = method_data();
1684     if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1685         ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1686       return InvocationCounter::count_limit;
1687     } else {
1688       return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1689              ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1690     }
1691   } else {
1692     return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1693   }
1694 }
1695 
1696 int Method::backedge_count() {
1697   MethodCounters *mcs = method_counters();
1698   if (TieredCompilation) {
1699     MethodData* const mdo = method_data();
1700     if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1701         ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1702       return InvocationCounter::count_limit;
1703     } else {
1704       return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1705              ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1706     }
1707   } else {
1708     return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1709   }
1710 }
1711 
1712 int Method::highest_comp_level() const {
1713   const MethodCounters* mcs = method_counters();
1714   if (mcs != NULL) {
1715     return mcs->highest_comp_level();
1716   } else {
1717     return CompLevel_none;
1718   }
1719 }
1720 
1721 int Method::highest_osr_comp_level() const {
1722   const MethodCounters* mcs = method_counters();
1723   if (mcs != NULL) {
1724     return mcs->highest_osr_comp_level();
1725   } else {
1726     return CompLevel_none;
1727   }
1728 }
1729 
1730 void Method::set_highest_comp_level(int level) {
1731   MethodCounters* mcs = method_counters();
1732   if (mcs != NULL) {
1733     mcs->set_highest_comp_level(level);
1734   }
1735 }
1736 
1737 void Method::set_highest_osr_comp_level(int level) {
1738   MethodCounters* mcs = method_counters();
1739   if (mcs != NULL) {
1740     mcs->set_highest_osr_comp_level(level);
1741   }
1742 }
1743 
1744 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1745   _bci = bci;
1746   _name_index = m->name_index();
1747   _signature_index = m->signature_index();
1748   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1749   if (_orig_bytecode == Bytecodes::_breakpoint)
1750     _orig_bytecode = m->orig_bytecode_at(_bci);
1751   _next = NULL;
1752 }
1753 
1754 void BreakpointInfo::set(Method* method) {
1755 #ifdef ASSERT
1756   {
1757     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
1758     if (code == Bytecodes::_breakpoint)
1759       code = method->orig_bytecode_at(_bci);
1760     assert(orig_bytecode() == code, "original bytecode must be the same");
1761   }
1762 #endif
1763   Thread *thread = Thread::current();
1764   *method->bcp_from(_bci) = Bytecodes::_breakpoint;
1765   method->incr_number_of_breakpoints(thread);
1766   SystemDictionary::notice_modification();
1767   {
1768     // Deoptimize all dependents on this method
1769     HandleMark hm(thread);
1770     methodHandle mh(thread, method);
1771     CodeCache::flush_dependents_on_method(mh);
1772   }
1773 }
1774 
1775 void BreakpointInfo::clear(Method* method) {
1776   *method->bcp_from(_bci) = orig_bytecode();
1777   assert(method->number_of_breakpoints() > 0, "must not go negative");
1778   method->decr_number_of_breakpoints(Thread::current());
1779 }
1780 
1781 // jmethodID handling
1782 
1783 // This is a block allocating object, sort of like JNIHandleBlock, only a
1784 // lot simpler.
1785 // It's allocated on the CHeap because once we allocate a jmethodID, we can
1786 // never get rid of it.
1787 
1788 static const int min_block_size = 8;
1789 
1790 class JNIMethodBlockNode : public CHeapObj<mtClass> {
1791   friend class JNIMethodBlock;
1792   Method**        _methods;
1793   int             _number_of_methods;
1794   int             _top;
1795   JNIMethodBlockNode* _next;
1796 
1797  public:
1798 
1799   JNIMethodBlockNode(int num_methods = min_block_size);
1800 
1801   ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
1802 
1803   void ensure_methods(int num_addl_methods) {
1804     if (_top < _number_of_methods) {
1805       num_addl_methods -= _number_of_methods - _top;
1806       if (num_addl_methods <= 0) {
1807         return;
1808       }
1809     }
1810     if (_next == NULL) {
1811       _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
1812     } else {
1813       _next->ensure_methods(num_addl_methods);
1814     }
1815   }
1816 };
1817 
1818 class JNIMethodBlock : public CHeapObj<mtClass> {
1819   JNIMethodBlockNode _head;
1820   JNIMethodBlockNode *_last_free;
1821  public:
1822   static Method* const _free_method;
1823 
1824   JNIMethodBlock(int initial_capacity = min_block_size)
1825       : _head(initial_capacity), _last_free(&_head) {}
1826 
1827   void ensure_methods(int num_addl_methods) {
1828     _last_free->ensure_methods(num_addl_methods);
1829   }
1830 
1831   Method** add_method(Method* m) {
1832     for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
1833       if (b->_top < b->_number_of_methods) {
1834         // top points to the next free entry.
1835         int i = b->_top;
1836         b->_methods[i] = m;
1837         b->_top++;
1838         _last_free = b;
1839         return &(b->_methods[i]);
1840       } else if (b->_top == b->_number_of_methods) {
1841         // if the next free entry ran off the block see if there's a free entry
1842         for (int i = 0; i < b->_number_of_methods; i++) {
1843           if (b->_methods[i] == _free_method) {
1844             b->_methods[i] = m;
1845             _last_free = b;
1846             return &(b->_methods[i]);
1847           }
1848         }
1849         // Only check each block once for frees.  They're very unlikely.
1850         // Increment top past the end of the block.
1851         b->_top++;
1852       }
1853       // need to allocate a next block.
1854       if (b->_next == NULL) {
1855         b->_next = _last_free = new JNIMethodBlockNode();
1856       }
1857     }
1858     guarantee(false, "Should always allocate a free block");
1859     return NULL;
1860   }
1861 
1862   bool contains(Method** m) {
1863     if (m == NULL) return false;
1864     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
1865       if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
1866         // This is a bit of extra checking, for two reasons.  One is
1867         // that contains() deals with pointers that are passed in by
1868         // JNI code, so making sure that the pointer is aligned
1869         // correctly is valuable.  The other is that <= and > are
1870         // technically not defined on pointers, so the if guard can
1871         // pass spuriously; no modern compiler is likely to make that
1872         // a problem, though (and if one did, the guard could also
1873         // fail spuriously, which would be bad).
1874         ptrdiff_t idx = m - b->_methods;
1875         if (b->_methods + idx == m) {
1876           return true;
1877         }
1878       }
1879     }
1880     return false;  // not found
1881   }
1882 
1883   // Doesn't really destroy it, just marks it as free so it can be reused.
1884   void destroy_method(Method** m) {
1885 #ifdef ASSERT
1886     assert(contains(m), "should be a methodID");
1887 #endif // ASSERT
1888     *m = _free_method;
1889   }
1890 
1891   // During class unloading the methods are cleared, which is different
1892   // than freed.
1893   void clear_all_methods() {
1894     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
1895       for (int i = 0; i< b->_number_of_methods; i++) {
1896         b->_methods[i] = NULL;
1897       }
1898     }
1899   }
1900 #ifndef PRODUCT
1901   int count_methods() {
1902     // count all allocated methods
1903     int count = 0;
1904     for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
1905       for (int i = 0; i< b->_number_of_methods; i++) {
1906         if (b->_methods[i] != _free_method) count++;
1907       }
1908     }
1909     return count;
1910   }
1911 #endif // PRODUCT
1912 };
1913 
1914 // Something that can't be mistaken for an address or a markOop
1915 Method* const JNIMethodBlock::_free_method = (Method*)55;
1916 
1917 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _next(NULL), _top(0) {
1918   _number_of_methods = MAX2(num_methods, min_block_size);
1919   _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
1920   for (int i = 0; i < _number_of_methods; i++) {
1921     _methods[i] = JNIMethodBlock::_free_method;
1922   }
1923 }
1924 
1925 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
1926   ClassLoaderData* cld = loader_data;
1927   if (!SafepointSynchronize::is_at_safepoint()) {
1928     // Have to add jmethod_ids() to class loader data thread-safely.
1929     // Also have to add the method to the list safely, which the cld lock
1930     // protects as well.
1931     MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
1932     if (cld->jmethod_ids() == NULL) {
1933       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
1934     } else {
1935       cld->jmethod_ids()->ensure_methods(capacity);
1936     }
1937   } else {
1938     // At safepoint, we are single threaded and can set this.
1939     if (cld->jmethod_ids() == NULL) {
1940       cld->set_jmethod_ids(new JNIMethodBlock(capacity));
1941     } else {
1942       cld->jmethod_ids()->ensure_methods(capacity);
1943     }
1944   }
1945 }
1946 
1947 // Add a method id to the jmethod_ids
1948 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
1949   ClassLoaderData* cld = loader_data;
1950 
1951   if (!SafepointSynchronize::is_at_safepoint()) {
1952     // Have to add jmethod_ids() to class loader data thread-safely.
1953     // Also have to add the method to the list safely, which the cld lock
1954     // protects as well.
1955     MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
1956     if (cld->jmethod_ids() == NULL) {
1957       cld->set_jmethod_ids(new JNIMethodBlock());
1958     }
1959     // jmethodID is a pointer to Method*
1960     return (jmethodID)cld->jmethod_ids()->add_method(m);
1961   } else {
1962     // At safepoint, we are single threaded and can set this.
1963     if (cld->jmethod_ids() == NULL) {
1964       cld->set_jmethod_ids(new JNIMethodBlock());
1965     }
1966     // jmethodID is a pointer to Method*
1967     return (jmethodID)cld->jmethod_ids()->add_method(m);
1968   }
1969 }
1970 
1971 // Mark a jmethodID as free.  This is called when there is a data race in
1972 // InstanceKlass while creating the jmethodID cache.
1973 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
1974   ClassLoaderData* cld = loader_data;
1975   Method** ptr = (Method**)m;
1976   assert(cld->jmethod_ids() != NULL, "should have method handles");
1977   cld->jmethod_ids()->destroy_method(ptr);
1978 }
1979 
1980 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
1981   // Can't assert the method_holder is the same because the new method has the
1982   // scratch method holder.
1983   assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
1984            == new_method->method_holder()->class_loader(),
1985          "changing to a different class loader");
1986   // Just change the method in place, jmethodID pointer doesn't change.
1987   *((Method**)jmid) = new_method;
1988 }
1989 
1990 bool Method::is_method_id(jmethodID mid) {
1991   Method* m = resolve_jmethod_id(mid);
1992   assert(m != NULL, "should be called with non-null method");
1993   InstanceKlass* ik = m->method_holder();
1994   ClassLoaderData* cld = ik->class_loader_data();
1995   if (cld->jmethod_ids() == NULL) return false;
1996   return (cld->jmethod_ids()->contains((Method**)mid));
1997 }
1998 
1999 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2000   if (mid == NULL) return NULL;
2001   Method* o = resolve_jmethod_id(mid);
2002   if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
2003     return NULL;
2004   }
2005   return o;
2006 };
2007 
2008 void Method::set_on_stack(const bool value) {
2009   // Set both the method itself and its constant pool.  The constant pool
2010   // on stack means some method referring to it is also on the stack.
2011   constants()->set_on_stack(value);
2012 
2013   bool already_set = on_stack();
2014   _access_flags.set_on_stack(value);
2015   if (value && !already_set) {
2016     MetadataOnStackMark::record(this);
2017   }
2018 }
2019 
2020 // Called when the class loader is unloaded to make all methods weak.
2021 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2022   loader_data->jmethod_ids()->clear_all_methods();
2023 }
2024 
2025 bool Method::has_method_vptr(const void* ptr) {
2026   Method m;
2027   // This assumes that the vtbl pointer is the first word of a C++ object.
2028   // This assumption is also in universe.cpp patch_klass_vtble
2029   void* vtbl2 = dereference_vptr((const void*)&m);
2030   void* this_vtbl = dereference_vptr(ptr);
2031   return vtbl2 == this_vtbl;
2032 }
2033 
2034 // Check that this pointer is valid by checking that the vtbl pointer matches
2035 bool Method::is_valid_method() const {
2036   if (this == NULL) {
2037     return false;
2038   } else if (!is_metaspace_object()) {
2039     return false;
2040   } else {
2041     return has_method_vptr((const void*)this);
2042   }
2043 }
2044 
2045 #ifndef PRODUCT
2046 void Method::print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) {
2047   out->print_cr("jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2048 }
2049 #endif // PRODUCT
2050 
2051 
2052 // Printing
2053 
2054 #ifndef PRODUCT
2055 
2056 void Method::print_on(outputStream* st) const {
2057   ResourceMark rm;
2058   assert(is_method(), "must be method");
2059   st->print_cr("%s", internal_name());
2060   // get the effect of PrintOopAddress, always, for methods:
2061   st->print_cr(" - this oop:          " INTPTR_FORMAT, p2i(this));
2062   st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();
2063   st->print   (" - constants:         " INTPTR_FORMAT " ", p2i(constants()));
2064   constants()->print_value_on(st); st->cr();
2065   st->print   (" - access:            0x%x  ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2066   st->print   (" - name:              ");    name()->print_value_on(st); st->cr();
2067   st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();
2068   st->print_cr(" - max stack:         %d",   max_stack());
2069   st->print_cr(" - max locals:        %d",   max_locals());
2070   st->print_cr(" - size of params:    %d",   size_of_parameters());
2071   st->print_cr(" - method size:       %d",   method_size());
2072   if (intrinsic_id() != vmIntrinsics::_none)
2073     st->print_cr(" - intrinsic id:      %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
2074   if (highest_comp_level() != CompLevel_none)
2075     st->print_cr(" - highest level:     %d", highest_comp_level());
2076   st->print_cr(" - vtable index:      %d",   _vtable_index);
2077   st->print_cr(" - i2i entry:         " INTPTR_FORMAT, p2i(interpreter_entry()));
2078   st->print(   " - adapters:          ");
2079   AdapterHandlerEntry* a = ((Method*)this)->adapter();
2080   if (a == NULL)
2081     st->print_cr(INTPTR_FORMAT, p2i(a));
2082   else
2083     a->print_adapter_on(st);
2084   st->print_cr(" - compiled entry     " INTPTR_FORMAT, p2i(from_compiled_entry()));
2085   st->print_cr(" - code size:         %d",   code_size());
2086   if (code_size() != 0) {
2087     st->print_cr(" - code start:        " INTPTR_FORMAT, p2i(code_base()));
2088     st->print_cr(" - code end (excl):   " INTPTR_FORMAT, p2i(code_base() + code_size()));
2089   }
2090   if (method_data() != NULL) {
2091     st->print_cr(" - method data:       " INTPTR_FORMAT, p2i(method_data()));
2092   }
2093   st->print_cr(" - checked ex length: %d",   checked_exceptions_length());
2094   if (checked_exceptions_length() > 0) {
2095     CheckedExceptionElement* table = checked_exceptions_start();
2096     st->print_cr(" - checked ex start:  " INTPTR_FORMAT, p2i(table));
2097     if (Verbose) {
2098       for (int i = 0; i < checked_exceptions_length(); i++) {
2099         st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2100       }
2101     }
2102   }
2103   if (has_linenumber_table()) {
2104     u_char* table = compressed_linenumber_table();
2105     st->print_cr(" - linenumber start:  " INTPTR_FORMAT, p2i(table));
2106     if (Verbose) {
2107       CompressedLineNumberReadStream stream(table);
2108       while (stream.read_pair()) {
2109         st->print_cr("   - line %d: %d", stream.line(), stream.bci());
2110       }
2111     }
2112   }
2113   st->print_cr(" - localvar length:   %d",   localvariable_table_length());
2114   if (localvariable_table_length() > 0) {
2115     LocalVariableTableElement* table = localvariable_table_start();
2116     st->print_cr(" - localvar start:    " INTPTR_FORMAT, p2i(table));
2117     if (Verbose) {
2118       for (int i = 0; i < localvariable_table_length(); i++) {
2119         int bci = table[i].start_bci;
2120         int len = table[i].length;
2121         const char* name = constants()->printable_name_at(table[i].name_cp_index);
2122         const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2123         int slot = table[i].slot;
2124         st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2125       }
2126     }
2127   }
2128   if (code() != NULL) {
2129     st->print   (" - compiled code: ");
2130     code()->print_value_on(st);
2131   }
2132   if (is_native()) {
2133     st->print_cr(" - native function:   " INTPTR_FORMAT, p2i(native_function()));
2134     st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2135   }
2136 }
2137 
2138 #endif //PRODUCT
2139 
2140 void Method::print_value_on(outputStream* st) const {
2141   assert(is_method(), "must be method");
2142   st->print("%s", internal_name());
2143   print_address_on(st);
2144   st->print(" ");
2145   name()->print_value_on(st);
2146   st->print(" ");
2147   signature()->print_value_on(st);
2148   st->print(" in ");
2149   method_holder()->print_value_on(st);
2150   if (WizardMode) st->print("#%d", _vtable_index);
2151   if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2152   if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2153 }
2154 
2155 #if INCLUDE_SERVICES
2156 // Size Statistics
2157 void Method::collect_statistics(KlassSizeStats *sz) const {
2158   int mysize = sz->count(this);
2159   sz->_method_bytes += mysize;
2160   sz->_method_all_bytes += mysize;
2161   sz->_rw_bytes += mysize;
2162 
2163   if (constMethod()) {
2164     constMethod()->collect_statistics(sz);
2165   }
2166   if (method_data()) {
2167     method_data()->collect_statistics(sz);
2168   }
2169 }
2170 #endif // INCLUDE_SERVICES
2171 
2172 // LogTouchedMethods and PrintTouchedMethods
2173 
2174 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2175 // the Method may be garbage collected. Let's roll our own hash table.
2176 class TouchedMethodRecord : CHeapObj<mtTracing> {
2177 public:
2178   // It's OK to store Symbols here because they will NOT be GC'ed if
2179   // LogTouchedMethods is enabled.
2180   TouchedMethodRecord* _next;
2181   Symbol* _class_name;
2182   Symbol* _method_name;
2183   Symbol* _method_signature;
2184 };
2185 
2186 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2187 static TouchedMethodRecord** _touched_method_table = NULL;
2188 
2189 void Method::log_touched(TRAPS) {
2190 
2191   const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2192   Symbol* my_class = klass_name();
2193   Symbol* my_name  = name();
2194   Symbol* my_sig   = signature();
2195 
2196   unsigned int hash = my_class->identity_hash() +
2197                       my_name->identity_hash() +
2198                       my_sig->identity_hash();
2199   juint index = juint(hash) % table_size;
2200 
2201   MutexLocker ml(TouchedMethodLog_lock, THREAD);
2202   if (_touched_method_table == NULL) {
2203     _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2204                                               mtTracing, CURRENT_PC);
2205     memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2206   }
2207 
2208   TouchedMethodRecord* ptr = _touched_method_table[index];
2209   while (ptr) {
2210     if (ptr->_class_name       == my_class &&
2211         ptr->_method_name      == my_name &&
2212         ptr->_method_signature == my_sig) {
2213       return;
2214     }
2215     if (ptr->_next == NULL) break;
2216     ptr = ptr->_next;
2217   }
2218   TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2219   my_class->set_permanent();  // prevent reclaimed by GC
2220   my_name->set_permanent();
2221   my_sig->set_permanent();
2222   nptr->_class_name         = my_class;
2223   nptr->_method_name        = my_name;
2224   nptr->_method_signature   = my_sig;
2225   nptr->_next               = NULL;
2226 
2227   if (ptr == NULL) {
2228     // first
2229     _touched_method_table[index] = nptr;
2230   } else {
2231     ptr->_next = nptr;
2232   }
2233 }
2234 
2235 void Method::print_touched_methods(outputStream* out) {
2236   MutexLockerEx ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2237   out->print_cr("# Method::print_touched_methods version 1");
2238   if (_touched_method_table) {
2239     for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2240       TouchedMethodRecord* ptr = _touched_method_table[i];
2241       while(ptr) {
2242         ptr->_class_name->print_symbol_on(out);       out->print(".");
2243         ptr->_method_name->print_symbol_on(out);      out->print(":");
2244         ptr->_method_signature->print_symbol_on(out); out->cr();
2245         ptr = ptr->_next;
2246       }
2247     }
2248   }
2249 }
2250 
2251 // Verification
2252 
2253 void Method::verify_on(outputStream* st) {
2254   guarantee(is_method(), "object must be method");
2255   guarantee(constants()->is_constantPool(), "should be constant pool");
2256   guarantee(constMethod()->is_constMethod(), "should be ConstMethod*");
2257   MethodData* md = method_data();
2258   guarantee(md == NULL ||
2259       md->is_methodData(), "should be method data");
2260 }
--- EOF ---