1 /*
   2  * Copyright (c) 1997, 2016, 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/debugInfoRec.hpp"
  29 #include "gc_interface/collectedHeap.inline.hpp"
  30 #include "interpreter/bytecodeStream.hpp"
  31 #include "interpreter/bytecodeTracer.hpp"
  32 #include "interpreter/bytecodes.hpp"
  33 #include "interpreter/interpreter.hpp"
  34 #include "interpreter/oopMapCache.hpp"
  35 #include "memory/gcLocker.hpp"
  36 #include "memory/generation.hpp"
  37 #include "memory/heapInspection.hpp"
  38 #include "memory/metadataFactory.hpp"
  39 #include "memory/oopFactory.hpp"
  40 #include "oops/constMethod.hpp"
  41 #include "oops/methodData.hpp"
  42 #include "oops/method.hpp"
  43 #include "oops/oop.inline.hpp"
  44 #include "oops/symbol.hpp"
  45 #include "prims/jvmtiExport.hpp"
  46 #include "prims/methodHandles.hpp"
  47 #include "prims/nativeLookup.hpp"
  48 #include "runtime/arguments.hpp"
  49 #include "runtime/compilationPolicy.hpp"
  50 #include "runtime/frame.inline.hpp"
  51 #include "runtime/handles.inline.hpp"
  52 #include "runtime/orderAccess.inline.hpp"
  53 #include "runtime/relocator.hpp"
  54 #include "runtime/sharedRuntime.hpp"
  55 #include "runtime/signature.hpp"
  56 #include "utilities/quickSort.hpp"
  57 #include "utilities/xmlstream.hpp"
  58 
  59 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  60 
  61 // Implementation of Method
  62 
  63 Method* Method::allocate(ClassLoaderData* loader_data,
  64                          int byte_code_size,
  65                          AccessFlags access_flags,
  66                          InlineTableSizes* sizes,
  67                          ConstMethod::MethodType method_type,
  68                          TRAPS) {
  69   assert(!access_flags.is_native() || byte_code_size == 0,
  70          "native methods should not contain byte codes");
  71   ConstMethod* cm = ConstMethod::allocate(loader_data,
  72                                           byte_code_size,
  73                                           sizes,
  74                                           method_type,
  75                                           CHECK_NULL);
  76 
  77   int size = Method::size(access_flags.is_native());
  78 
  79   return new (loader_data, size, false, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags, size);
  80 }
  81 
  82 Method::Method(ConstMethod* xconst, AccessFlags access_flags, int size) {
  83   No_Safepoint_Verifier no_safepoint;
  84   set_constMethod(xconst);
  85   set_access_flags(access_flags);
  86   set_method_size(size);
  87   set_intrinsic_id(vmIntrinsics::_none);
  88   set_jfr_towrite(false);
  89   set_force_inline(false);
  90   set_hidden(false);
  91   set_dont_inline(false);
  92   set_has_injected_profile(false);
  93   set_method_data(NULL);
  94   clear_method_counters();
  95   set_vtable_index(Method::garbage_vtable_index);
  96 
  97   // Fix and bury in Method*
  98   set_interpreter_entry(NULL); // sets i2i entry and from_int
  99   set_adapter_entry(NULL);
 100   clear_code(); // from_c/from_i get set to c2i/i2i
 101 
 102   if (access_flags.is_native()) {
 103     clear_native_function();
 104     set_signature_handler(NULL);
 105   }
 106 
 107   NOT_PRODUCT(set_compiled_invocation_count(0);)
 108 }
 109 
 110 // Release Method*.  The nmethod will be gone when we get here because
 111 // we've walked the code cache.
 112 void Method::deallocate_contents(ClassLoaderData* loader_data) {
 113   MetadataFactory::free_metadata(loader_data, constMethod());
 114   set_constMethod(NULL);
 115   MetadataFactory::free_metadata(loader_data, method_data());
 116   set_method_data(NULL);
 117   MetadataFactory::free_metadata(loader_data, method_counters());
 118   clear_method_counters();
 119   // The nmethod will be gone when we get here.
 120   if (code() != NULL) _code = NULL;
 121 }
 122 
 123 address Method::get_i2c_entry() {
 124   assert(_adapter != NULL, "must have");
 125   return _adapter->get_i2c_entry();
 126 }
 127 
 128 address Method::get_c2i_entry() {
 129   assert(_adapter != NULL, "must have");
 130   return _adapter->get_c2i_entry();
 131 }
 132 
 133 address Method::get_c2i_unverified_entry() {
 134   assert(_adapter != NULL, "must have");
 135   return _adapter->get_c2i_unverified_entry();
 136 }
 137 
 138 char* Method::name_and_sig_as_C_string() const {
 139   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
 140 }
 141 
 142 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
 143   return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
 144 }
 145 
 146 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
 147   const char* klass_name = klass->external_name();
 148   int klass_name_len  = (int)strlen(klass_name);
 149   int method_name_len = method_name->utf8_length();
 150   int len             = klass_name_len + 1 + method_name_len + signature->utf8_length();
 151   char* dest          = NEW_RESOURCE_ARRAY(char, len + 1);
 152   strcpy(dest, klass_name);
 153   dest[klass_name_len] = '.';
 154   strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
 155   strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
 156   dest[len] = 0;
 157   return dest;
 158 }
 159 
 160 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
 161   Symbol* klass_name = klass->name();
 162   klass_name->as_klass_external_name(buf, size);
 163   int len = (int)strlen(buf);
 164 
 165   if (len < size - 1) {
 166     buf[len++] = '.';
 167 
 168     method_name->as_C_string(&(buf[len]), size - len);
 169     len = (int)strlen(buf);
 170 
 171     signature->as_C_string(&(buf[len]), size - len);
 172   }
 173 
 174   return buf;
 175 }
 176 
 177 int Method::fast_exception_handler_bci_for(methodHandle mh, KlassHandle ex_klass, int throw_bci, TRAPS) {
 178   // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
 179   // access exception table
 180   ExceptionTable table(mh());
 181   int length = table.length();
 182   // iterate through all entries sequentially
 183   constantPoolHandle pool(THREAD, mh->constants());
 184   for (int i = 0; i < length; i ++) {
 185     //reacquire the table in case a GC happened
 186     ExceptionTable table(mh());
 187     int beg_bci = table.start_pc(i);
 188     int end_bci = table.end_pc(i);
 189     assert(beg_bci <= end_bci, "inconsistent exception table");
 190     if (beg_bci <= throw_bci && throw_bci < end_bci) {
 191       // exception handler bci range covers throw_bci => investigate further
 192       int handler_bci = table.handler_pc(i);
 193       int klass_index = table.catch_type_index(i);
 194       if (klass_index == 0) {
 195         return handler_bci;
 196       } else if (ex_klass.is_null()) {
 197         return handler_bci;
 198       } else {
 199         // we know the exception class => get the constraint class
 200         // this may require loading of the constraint class; if verification
 201         // fails or some other exception occurs, return handler_bci
 202         Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
 203         KlassHandle klass = KlassHandle(THREAD, k);
 204         assert(klass.not_null(), "klass not loaded");
 205         if (ex_klass->is_subtype_of(klass())) {
 206           return handler_bci;
 207         }
 208       }
 209     }
 210   }
 211 
 212   return -1;
 213 }
 214 
 215 void Method::mask_for(int bci, InterpreterOopMap* mask) {
 216 
 217   Thread* myThread    = Thread::current();
 218   methodHandle h_this(myThread, this);
 219 #ifdef ASSERT
 220   bool has_capability = myThread->is_VM_thread() ||
 221                         myThread->is_ConcurrentGC_thread() ||
 222                         myThread->is_GC_task_thread();
 223 
 224   if (!has_capability) {
 225     if (!VerifyStack && !VerifyLastFrame) {
 226       // verify stack calls this outside VM thread
 227       warning("oopmap should only be accessed by the "
 228               "VM, GC task or CMS threads (or during debugging)");
 229       InterpreterOopMap local_mask;
 230       method_holder()->mask_for(h_this, bci, &local_mask);
 231       local_mask.print();
 232     }
 233   }
 234 #endif
 235   method_holder()->mask_for(h_this, bci, mask);
 236   return;
 237 }
 238 
 239 
 240 int Method::bci_from(address bcp) const {
 241 #ifdef ASSERT
 242   { ResourceMark rm;
 243   assert(is_native() && bcp == code_base() || contains(bcp) || is_error_reported(),
 244          err_msg("bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s", bcp, name_and_sig_as_C_string()));
 245   }
 246 #endif
 247   return bcp - code_base();
 248 }
 249 
 250 
 251 // Return (int)bcx if it appears to be a valid BCI.
 252 // Return bci_from((address)bcx) if it appears to be a valid BCP.
 253 // Return -1 otherwise.
 254 // Used by profiling code, when invalid data is a possibility.
 255 // The caller is responsible for validating the Method* itself.
 256 int Method::validate_bci_from_bcx(intptr_t bcx) const {
 257   // keep bci as -1 if not a valid bci
 258   int bci = -1;
 259   if (bcx == 0 || (address)bcx == code_base()) {
 260     // code_size() may return 0 and we allow 0 here
 261     // the method may be native
 262     bci = 0;
 263   } else if (frame::is_bci(bcx)) {
 264     if (bcx < code_size()) {
 265       bci = (int)bcx;
 266     }
 267   } else if (contains((address)bcx)) {
 268     bci = (address)bcx - code_base();
 269   }
 270   // Assert that if we have dodged any asserts, bci is negative.
 271   assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
 272   return bci;
 273 }
 274 
 275 address Method::bcp_from(int bci) const {
 276   assert((is_native() && bci == 0)  || (!is_native() && 0 <= bci && bci < code_size()), err_msg("illegal bci: %d", bci));
 277   address bcp = code_base() + bci;
 278   assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
 279   return bcp;
 280 }
 281 
 282 
 283 int Method::size(bool is_native) {
 284   // If native, then include pointers for native_function and signature_handler
 285   int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
 286   int extra_words = align_size_up(extra_bytes, BytesPerWord) / BytesPerWord;
 287   return align_object_size(header_size() + extra_words);
 288 }
 289 
 290 
 291 Symbol* Method::klass_name() const {
 292   Klass* k = method_holder();
 293   assert(k->is_klass(), "must be klass");
 294   InstanceKlass* ik = (InstanceKlass*) k;
 295   return ik->name();
 296 }
 297 
 298 
 299 // Attempt to return method oop to original state.  Clear any pointers
 300 // (to objects outside the shared spaces).  We won't be able to predict
 301 // where they should point in a new JVM.  Further initialize some
 302 // entries now in order allow them to be write protected later.
 303 
 304 void Method::remove_unshareable_info() {
 305   unlink_method();
 306 }
 307 
 308 
 309 bool Method::was_executed_more_than(int n) {
 310   // Invocation counter is reset when the Method* is compiled.
 311   // If the method has compiled code we therefore assume it has
 312   // be excuted more than n times.
 313   if (is_accessor() || is_empty_method() || (code() != NULL)) {
 314     // interpreter doesn't bump invocation counter of trivial methods
 315     // compiler does not bump invocation counter of compiled methods
 316     return true;
 317   }
 318   else if ((method_counters() != NULL &&
 319             method_counters()->invocation_counter()->carry()) ||
 320            (method_data() != NULL &&
 321             method_data()->invocation_counter()->carry())) {
 322     // The carry bit is set when the counter overflows and causes
 323     // a compilation to occur.  We don't know how many times
 324     // the counter has been reset, so we simply assume it has
 325     // been executed more than n times.
 326     return true;
 327   } else {
 328     return invocation_count() > n;
 329   }
 330 }
 331 
 332 #ifndef PRODUCT
 333 void Method::print_invocation_count() {
 334   if (is_static()) tty->print("static ");
 335   if (is_final()) tty->print("final ");
 336   if (is_synchronized()) tty->print("synchronized ");
 337   if (is_native()) tty->print("native ");
 338   method_holder()->name()->print_symbol_on(tty);
 339   tty->print(".");
 340   name()->print_symbol_on(tty);
 341   signature()->print_symbol_on(tty);
 342 
 343   if (WizardMode) {
 344     // dump the size of the byte codes
 345     tty->print(" {%d}", code_size());
 346   }
 347   tty->cr();
 348 
 349   tty->print_cr ("  interpreter_invocation_count: %8d ", interpreter_invocation_count());
 350   tty->print_cr ("  invocation_counter:           %8d ", invocation_count());
 351   tty->print_cr ("  backedge_counter:             %8d ", backedge_count());
 352   if (CountCompiledCalls) {
 353     tty->print_cr ("  compiled_invocation_count: %8d ", compiled_invocation_count());
 354   }
 355 
 356 }
 357 #endif
 358 
 359 // Build a MethodData* object to hold information about this method
 360 // collected in the interpreter.
 361 void Method::build_interpreter_method_data(methodHandle method, TRAPS) {
 362   // Do not profile method if current thread holds the pending list lock,
 363   // which avoids deadlock for acquiring the MethodData_lock.
 364   if (InstanceRefKlass::owns_pending_list_lock((JavaThread*)THREAD)) {
 365     return;
 366   }
 367 
 368   // Grab a lock here to prevent multiple
 369   // MethodData*s from being created.
 370   MutexLocker ml(MethodData_lock, THREAD);
 371   if (method->method_data() == NULL) {
 372     ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
 373     MethodData* method_data = MethodData::allocate(loader_data, method, CHECK);
 374     method->set_method_data(method_data);
 375     if (PrintMethodData && (Verbose || WizardMode)) {
 376       ResourceMark rm(THREAD);
 377       tty->print("build_interpreter_method_data for ");
 378       method->print_name(tty);
 379       tty->cr();
 380       // At the end of the run, the MDO, full of data, will be dumped.
 381     }
 382   }
 383 }
 384 
 385 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
 386   methodHandle mh(m);
 387   ClassLoaderData* loader_data = mh->method_holder()->class_loader_data();
 388   MethodCounters* counters = MethodCounters::allocate(loader_data, CHECK_NULL);
 389   if (!mh->init_method_counters(counters)) {
 390     MetadataFactory::free_metadata(loader_data, counters);
 391   }
 392   return mh->method_counters();
 393 }
 394 
 395 void Method::cleanup_inline_caches() {
 396   // The current system doesn't use inline caches in the interpreter
 397   // => nothing to do (keep this method around for future use)
 398 }
 399 
 400 
 401 int Method::extra_stack_words() {
 402   // not an inline function, to avoid a header dependency on Interpreter
 403   return extra_stack_entries() * Interpreter::stackElementSize;
 404 }
 405 
 406 
 407 void Method::compute_size_of_parameters(Thread *thread) {
 408   ArgumentSizeComputer asc(signature());
 409   set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
 410 }
 411 
 412 BasicType Method::result_type() const {
 413   ResultTypeFinder rtf(signature());
 414   return rtf.type();
 415 }
 416 
 417 
 418 bool Method::is_empty_method() const {
 419   return  code_size() == 1
 420       && *code_base() == Bytecodes::_return;
 421 }
 422 
 423 
 424 bool Method::is_vanilla_constructor() const {
 425   // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
 426   // which only calls the superclass vanilla constructor and possibly does stores of
 427   // zero constants to local fields:
 428   //
 429   //   aload_0
 430   //   invokespecial
 431   //   indexbyte1
 432   //   indexbyte2
 433   //
 434   // followed by an (optional) sequence of:
 435   //
 436   //   aload_0
 437   //   aconst_null / iconst_0 / fconst_0 / dconst_0
 438   //   putfield
 439   //   indexbyte1
 440   //   indexbyte2
 441   //
 442   // followed by:
 443   //
 444   //   return
 445 
 446   assert(name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructors");
 447   assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
 448   int size = code_size();
 449   // Check if size match
 450   if (size == 0 || size % 5 != 0) return false;
 451   address cb = code_base();
 452   int last = size - 1;
 453   if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
 454     // Does not call superclass default constructor
 455     return false;
 456   }
 457   // Check optional sequence
 458   for (int i = 4; i < last; i += 5) {
 459     if (cb[i] != Bytecodes::_aload_0) return false;
 460     if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
 461     if (cb[i+2] != Bytecodes::_putfield) return false;
 462   }
 463   return true;
 464 }
 465 
 466 
 467 bool Method::compute_has_loops_flag() {
 468   BytecodeStream bcs(this);
 469   Bytecodes::Code bc;
 470 
 471   while ((bc = bcs.next()) >= 0) {
 472     switch( bc ) {
 473       case Bytecodes::_ifeq:
 474       case Bytecodes::_ifnull:
 475       case Bytecodes::_iflt:
 476       case Bytecodes::_ifle:
 477       case Bytecodes::_ifne:
 478       case Bytecodes::_ifnonnull:
 479       case Bytecodes::_ifgt:
 480       case Bytecodes::_ifge:
 481       case Bytecodes::_if_icmpeq:
 482       case Bytecodes::_if_icmpne:
 483       case Bytecodes::_if_icmplt:
 484       case Bytecodes::_if_icmpgt:
 485       case Bytecodes::_if_icmple:
 486       case Bytecodes::_if_icmpge:
 487       case Bytecodes::_if_acmpeq:
 488       case Bytecodes::_if_acmpne:
 489       case Bytecodes::_goto:
 490       case Bytecodes::_jsr:
 491         if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
 492         break;
 493 
 494       case Bytecodes::_goto_w:
 495       case Bytecodes::_jsr_w:
 496         if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
 497         break;
 498     }
 499   }
 500   _access_flags.set_loops_flag_init();
 501   return _access_flags.has_loops();
 502 }
 503 
 504 bool Method::is_final_method(AccessFlags class_access_flags) const {
 505   // or "does_not_require_vtable_entry"
 506   // default method or overpass can occur, is not final (reuses vtable entry)
 507   // private methods get vtable entries for backward class compatibility.
 508   if (is_overpass() || is_default_method())  return false;
 509   return is_final() || class_access_flags.is_final();
 510 }
 511 
 512 bool Method::is_final_method() const {
 513   return is_final_method(method_holder()->access_flags());
 514 }
 515 
 516 bool Method::is_default_method() const {
 517   if (method_holder() != NULL &&
 518       method_holder()->is_interface() &&
 519       !is_abstract()) {
 520     return true;
 521   } else {
 522     return false;
 523   }
 524 }
 525 
 526 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
 527   if (is_final_method(class_access_flags))  return true;
 528 #ifdef ASSERT
 529   ResourceMark rm;
 530   bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
 531   if (class_access_flags.is_interface()) {
 532       assert(is_nonv == is_static(), err_msg("is_nonv=%s", name_and_sig_as_C_string()));
 533   }
 534 #endif
 535   assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
 536   return vtable_index() == nonvirtual_vtable_index;
 537 }
 538 
 539 bool Method::can_be_statically_bound() const {
 540   return can_be_statically_bound(method_holder()->access_flags());
 541 }
 542 
 543 bool Method::is_accessor() const {
 544   if (code_size() != 5) return false;
 545   if (size_of_parameters() != 1) return false;
 546   if (java_code_at(0) != Bytecodes::_aload_0 ) return false;
 547   if (java_code_at(1) != Bytecodes::_getfield) return false;
 548   if (java_code_at(4) != Bytecodes::_areturn &&
 549       java_code_at(4) != Bytecodes::_ireturn ) return false;
 550   return true;
 551 }
 552 
 553 bool Method::is_constant_getter() const {
 554   int last_index = code_size() - 1;
 555   // Check if the first 1-3 bytecodes are a constant push
 556   // and the last bytecode is a return.
 557   return (2 <= code_size() && code_size() <= 4 &&
 558           Bytecodes::is_const(java_code_at(0)) &&
 559           Bytecodes::length_for(java_code_at(0)) == last_index &&
 560           Bytecodes::is_return(java_code_at(last_index)));
 561 }
 562 
 563 bool Method::is_initializer() const {
 564   return name() == vmSymbols::object_initializer_name() || is_static_initializer();
 565 }
 566 
 567 bool Method::has_valid_initializer_flags() const {
 568   return (is_static() ||
 569           method_holder()->major_version() < 51);
 570 }
 571 
 572 bool Method::is_static_initializer() const {
 573   // For classfiles version 51 or greater, ensure that the clinit method is
 574   // static.  Non-static methods with the name "<clinit>" are not static
 575   // initializers. (older classfiles exempted for backward compatibility)
 576   return name() == vmSymbols::class_initializer_name() &&
 577          has_valid_initializer_flags();
 578 }
 579 
 580 
 581 objArrayHandle Method::resolved_checked_exceptions_impl(Method* this_oop, TRAPS) {
 582   int length = this_oop->checked_exceptions_length();
 583   if (length == 0) {  // common case
 584     return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
 585   } else {
 586     methodHandle h_this(THREAD, this_oop);
 587     objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
 588     objArrayHandle mirrors (THREAD, m_oop);
 589     for (int i = 0; i < length; i++) {
 590       CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
 591       Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
 592       assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
 593       mirrors->obj_at_put(i, k->java_mirror());
 594     }
 595     return mirrors;
 596   }
 597 };
 598 
 599 
 600 int Method::line_number_from_bci(int bci) const {
 601   if (bci == SynchronizationEntryBCI) bci = 0;
 602   assert(bci == 0 || 0 <= bci && bci < code_size(), "illegal bci");
 603   int best_bci  =  0;
 604   int best_line = -1;
 605 
 606   if (has_linenumber_table()) {
 607     // The line numbers are a short array of 2-tuples [start_pc, line_number].
 608     // Not necessarily sorted and not necessarily one-to-one.
 609     CompressedLineNumberReadStream stream(compressed_linenumber_table());
 610     while (stream.read_pair()) {
 611       if (stream.bci() == bci) {
 612         // perfect match
 613         return stream.line();
 614       } else {
 615         // update best_bci/line
 616         if (stream.bci() < bci && stream.bci() >= best_bci) {
 617           best_bci  = stream.bci();
 618           best_line = stream.line();
 619         }
 620       }
 621     }
 622   }
 623   return best_line;
 624 }
 625 
 626 
 627 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
 628   if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
 629     Thread *thread = Thread::current();
 630     Symbol* klass_name = constants()->klass_name_at(klass_index);
 631     Handle loader(thread, method_holder()->class_loader());
 632     Handle prot  (thread, method_holder()->protection_domain());
 633     return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
 634   } else {
 635     return true;
 636   }
 637 }
 638 
 639 
 640 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
 641   int klass_index = constants()->klass_ref_index_at(refinfo_index);
 642   if (must_be_resolved) {
 643     // Make sure klass is resolved in constantpool.
 644     if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
 645   }
 646   return is_klass_loaded_by_klass_index(klass_index);
 647 }
 648 
 649 
 650 void Method::set_native_function(address function, bool post_event_flag) {
 651   assert(function != NULL, "use clear_native_function to unregister natives");
 652   assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
 653   address* native_function = native_function_addr();
 654 
 655   // We can see racers trying to place the same native function into place. Once
 656   // is plenty.
 657   address current = *native_function;
 658   if (current == function) return;
 659   if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
 660       function != NULL) {
 661     // native_method_throw_unsatisfied_link_error_entry() should only
 662     // be passed when post_event_flag is false.
 663     assert(function !=
 664       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 665       "post_event_flag mis-match");
 666 
 667     // post the bind event, and possible change the bind function
 668     JvmtiExport::post_native_method_bind(this, &function);
 669   }
 670   *native_function = function;
 671   // This function can be called more than once. We must make sure that we always
 672   // use the latest registered method -> check if a stub already has been generated.
 673   // If so, we have to make it not_entrant.
 674   nmethod* nm = code(); // Put it into local variable to guard against concurrent updates
 675   if (nm != NULL) {
 676     nm->make_not_entrant();
 677   }
 678 }
 679 
 680 
 681 bool Method::has_native_function() const {
 682   if (is_method_handle_intrinsic())
 683     return false;  // special-cased in SharedRuntime::generate_native_wrapper
 684   address func = native_function();
 685   return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
 686 }
 687 
 688 
 689 void Method::clear_native_function() {
 690   // Note: is_method_handle_intrinsic() is allowed here.
 691   set_native_function(
 692     SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 693     !native_bind_event_is_interesting);
 694   clear_code();
 695 }
 696 
 697 address Method::critical_native_function() {
 698   methodHandle mh(this);
 699   return NativeLookup::lookup_critical_entry(mh);
 700 }
 701 
 702 
 703 void Method::set_signature_handler(address handler) {
 704   address* signature_handler =  signature_handler_addr();
 705   *signature_handler = handler;
 706 }
 707 
 708 
 709 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
 710   if (PrintCompilation && report) {
 711     ttyLocker ttyl;
 712     tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
 713     if (comp_level == CompLevel_all) {
 714       tty->print("all levels ");
 715     } else {
 716       tty->print("levels ");
 717       for (int i = (int)CompLevel_none; i <= comp_level; i++) {
 718         tty->print("%d ", i);
 719       }
 720     }
 721     this->print_short_name(tty);
 722     int size = this->code_size();
 723     if (size > 0) {
 724       tty->print(" (%d bytes)", size);
 725     }
 726     if (reason != NULL) {
 727       tty->print("   %s", reason);
 728     }
 729     tty->cr();
 730   }
 731   if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
 732     ttyLocker ttyl;
 733     xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
 734                      os::current_thread_id(), is_osr, comp_level);
 735     if (reason != NULL) {
 736       xtty->print(" reason=\'%s\'", reason);
 737     }
 738     xtty->method(this);
 739     xtty->stamp();
 740     xtty->end_elem();
 741   }
 742 }
 743 
 744 bool Method::is_always_compilable() const {
 745   // Generated adapters must be compiled
 746   if (is_method_handle_intrinsic() && is_synthetic()) {
 747     assert(!is_not_c1_compilable(), "sanity check");
 748     assert(!is_not_c2_compilable(), "sanity check");
 749     return true;
 750   }
 751 
 752   return false;
 753 }
 754 
 755 bool Method::is_not_compilable(int comp_level) const {
 756   if (number_of_breakpoints() > 0)
 757     return true;
 758   if (is_always_compilable())
 759     return false;
 760   if (comp_level == CompLevel_any)
 761     return is_not_c1_compilable() || is_not_c2_compilable();
 762   if (is_c1_compile(comp_level))
 763     return is_not_c1_compilable();
 764   if (is_c2_compile(comp_level))
 765     return is_not_c2_compilable();
 766   return false;
 767 }
 768 
 769 // call this when compiler finds that this method is not compilable
 770 void Method::set_not_compilable(int comp_level, bool report, const char* reason) {
 771   if (is_always_compilable()) {
 772     // Don't mark a method which should be always compilable
 773     return;
 774   }
 775   print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
 776   if (comp_level == CompLevel_all) {
 777     set_not_c1_compilable();
 778     set_not_c2_compilable();
 779   } else {
 780     if (is_c1_compile(comp_level))
 781       set_not_c1_compilable();
 782     if (is_c2_compile(comp_level))
 783       set_not_c2_compilable();
 784   }
 785   CompilationPolicy::policy()->disable_compilation(this);
 786   assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
 787 }
 788 
 789 bool Method::is_not_osr_compilable(int comp_level) const {
 790   if (is_not_compilable(comp_level))
 791     return true;
 792   if (comp_level == CompLevel_any)
 793     return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
 794   if (is_c1_compile(comp_level))
 795     return is_not_c1_osr_compilable();
 796   if (is_c2_compile(comp_level))
 797     return is_not_c2_osr_compilable();
 798   return false;
 799 }
 800 
 801 void Method::set_not_osr_compilable(int comp_level, bool report, const char* reason) {
 802   print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
 803   if (comp_level == CompLevel_all) {
 804     set_not_c1_osr_compilable();
 805     set_not_c2_osr_compilable();
 806   } else {
 807     if (is_c1_compile(comp_level))
 808       set_not_c1_osr_compilable();
 809     if (is_c2_compile(comp_level))
 810       set_not_c2_osr_compilable();
 811   }
 812   CompilationPolicy::policy()->disable_compilation(this);
 813   assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
 814 }
 815 
 816 // Revert to using the interpreter and clear out the nmethod
 817 void Method::clear_code() {
 818 
 819   // this may be NULL if c2i adapters have not been made yet
 820   // Only should happen at allocate time.
 821   if (_adapter == NULL) {
 822     _from_compiled_entry    = NULL;
 823   } else {
 824     _from_compiled_entry    = _adapter->get_c2i_entry();
 825   }
 826   OrderAccess::storestore();
 827   _from_interpreted_entry = _i2i_entry;
 828   OrderAccess::storestore();
 829   _code = NULL;
 830 }
 831 
 832 // Called by class data sharing to remove any entry points (which are not shared)
 833 void Method::unlink_method() {
 834   _code = NULL;
 835   _i2i_entry = NULL;
 836   _from_interpreted_entry = NULL;
 837   if (is_native()) {
 838     *native_function_addr() = NULL;
 839     set_signature_handler(NULL);
 840   }
 841   NOT_PRODUCT(set_compiled_invocation_count(0);)
 842   _adapter = NULL;
 843   _from_compiled_entry = NULL;
 844 
 845   // In case of DumpSharedSpaces, _method_data should always be NULL.
 846   //
 847   // During runtime (!DumpSharedSpaces), when we are cleaning a
 848   // shared class that failed to load, this->link_method() may
 849   // have already been called (before an exception happened), so
 850   // this->_method_data may not be NULL.
 851   assert(!DumpSharedSpaces || _method_data == NULL, "unexpected method data?");
 852 
 853   set_method_data(NULL);
 854   clear_method_counters();
 855 }
 856 
 857 // Called when the method_holder is getting linked. Setup entrypoints so the method
 858 // is ready to be called from interpreter, compiler, and vtables.
 859 void Method::link_method(methodHandle h_method, TRAPS) {
 860   // If the code cache is full, we may reenter this function for the
 861   // leftover methods that weren't linked.
 862   if (_i2i_entry != NULL) return;
 863 
 864   assert(_adapter == NULL, "init'd to NULL" );
 865   assert( _code == NULL, "nothing compiled yet" );
 866 
 867   // Setup interpreter entrypoint
 868   assert(this == h_method(), "wrong h_method()" );
 869   address entry = Interpreter::entry_for_method(h_method);
 870   assert(entry != NULL, "interpreter entry must be non-null");
 871   // Sets both _i2i_entry and _from_interpreted_entry
 872   set_interpreter_entry(entry);
 873 
 874   // Don't overwrite already registered native entries.
 875   if (is_native() && !has_native_function()) {
 876     set_native_function(
 877       SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
 878       !native_bind_event_is_interesting);
 879   }
 880 
 881   // Setup compiler entrypoint.  This is made eagerly, so we do not need
 882   // special handling of vtables.  An alternative is to make adapters more
 883   // lazily by calling make_adapter() from from_compiled_entry() for the
 884   // normal calls.  For vtable calls life gets more complicated.  When a
 885   // call-site goes mega-morphic we need adapters in all methods which can be
 886   // called from the vtable.  We need adapters on such methods that get loaded
 887   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
 888   // problem we'll make these lazily later.
 889   (void) make_adapters(h_method, CHECK);
 890 
 891   // ONLY USE the h_method now as make_adapter may have blocked
 892 
 893 }
 894 
 895 address Method::make_adapters(methodHandle mh, TRAPS) {
 896   // Adapters for compiled code are made eagerly here.  They are fairly
 897   // small (generally < 100 bytes) and quick to make (and cached and shared)
 898   // so making them eagerly shouldn't be too expensive.
 899   AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
 900   if (adapter == NULL ) {
 901     THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "out of space in CodeCache for adapters");
 902   }
 903 
 904   mh->set_adapter_entry(adapter);
 905   mh->_from_compiled_entry = adapter->get_c2i_entry();
 906   return adapter->get_c2i_entry();
 907 }
 908 
 909 void Method::restore_unshareable_info(TRAPS) {
 910   // Since restore_unshareable_info can be called more than once for a method, don't
 911   // redo any work.   If this field is restored, there is nothing to do.
 912   if (_from_compiled_entry == NULL) {
 913     // restore method's vtable by calling a virtual function
 914     restore_vtable();
 915 
 916     methodHandle mh(THREAD, this);
 917     link_method(mh, CHECK);
 918   }
 919 }
 920 
 921 
 922 // The verified_code_entry() must be called when a invoke is resolved
 923 // on this method.
 924 
 925 // It returns the compiled code entry point, after asserting not null.
 926 // This function is called after potential safepoints so that nmethod
 927 // or adapter that it points to is still live and valid.
 928 // This function must not hit a safepoint!
 929 address Method::verified_code_entry() {
 930   debug_only(No_Safepoint_Verifier nsv;)
 931   assert(_from_compiled_entry != NULL, "must be set");
 932   return _from_compiled_entry;
 933 }
 934 
 935 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
 936 // (could be racing a deopt).
 937 // Not inline to avoid circular ref.
 938 bool Method::check_code() const {
 939   // cached in a register or local.  There's a race on the value of the field.
 940   nmethod *code = (nmethod *)OrderAccess::load_ptr_acquire(&_code);
 941   return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
 942 }
 943 
 944 // Install compiled code.  Instantly it can execute.
 945 void Method::set_code(methodHandle mh, nmethod *code) {
 946   assert( code, "use clear_code to remove code" );
 947   assert( mh->check_code(), "" );
 948 
 949   guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
 950 
 951   // These writes must happen in this order, because the interpreter will
 952   // directly jump to from_interpreted_entry which jumps to an i2c adapter
 953   // which jumps to _from_compiled_entry.
 954   mh->_code = code;             // Assign before allowing compiled code to exec
 955 
 956   int comp_level = code->comp_level();
 957   // In theory there could be a race here. In practice it is unlikely
 958   // and not worth worrying about.
 959   if (comp_level > mh->highest_comp_level()) {
 960     mh->set_highest_comp_level(comp_level);
 961   }
 962 
 963   OrderAccess::storestore();
 964 #ifdef SHARK
 965   mh->_from_interpreted_entry = code->insts_begin();
 966 #else //!SHARK
 967   mh->_from_compiled_entry = code->verified_entry_point();
 968   OrderAccess::storestore();
 969   // Instantly compiled code can execute.
 970   if (!mh->is_method_handle_intrinsic())
 971     mh->_from_interpreted_entry = mh->get_i2c_entry();
 972 #endif //!SHARK
 973 }
 974 
 975 
 976 bool Method::is_overridden_in(Klass* k) const {
 977   InstanceKlass* ik = InstanceKlass::cast(k);
 978 
 979   if (ik->is_interface()) return false;
 980 
 981   // If method is an interface, we skip it - except if it
 982   // is a miranda method
 983   if (method_holder()->is_interface()) {
 984     // Check that method is not a miranda method
 985     if (ik->lookup_method(name(), signature()) == NULL) {
 986       // No implementation exist - so miranda method
 987       return false;
 988     }
 989     return true;
 990   }
 991 
 992   assert(ik->is_subclass_of(method_holder()), "should be subklass");
 993   assert(ik->vtable() != NULL, "vtable should exist");
 994   if (!has_vtable_index()) {
 995     return false;
 996   } else {
 997     Method* vt_m = ik->method_at_vtable(vtable_index());
 998     return vt_m != this;
 999   }
1000 }
1001 
1002 
1003 // give advice about whether this Method* should be cached or not
1004 bool Method::should_not_be_cached() const {
1005   if (is_old()) {
1006     // This method has been redefined. It is either EMCP or obsolete
1007     // and we don't want to cache it because that would pin the method
1008     // down and prevent it from being collectible if and when it
1009     // finishes executing.
1010     return true;
1011   }
1012 
1013   // caching this method should be just fine
1014   return false;
1015 }
1016 
1017 
1018 /**
1019  *  Returns true if this is one of the specially treated methods for
1020  *  security related stack walks (like Reflection.getCallerClass).
1021  */
1022 bool Method::is_ignored_by_security_stack_walk() const {
1023   const bool use_new_reflection = JDK_Version::is_gte_jdk14x_version() && UseNewReflection;
1024 
1025   if (intrinsic_id() == vmIntrinsics::_invoke) {
1026     // This is Method.invoke() -- ignore it
1027     return true;
1028   }
1029   if (use_new_reflection &&
1030       method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1031     // This is an auxilary frame -- ignore it
1032     return true;
1033   }
1034   if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1035     // This is an internal adapter frame for method handles -- ignore it
1036     return true;
1037   }
1038   return false;
1039 }
1040 
1041 
1042 // Constant pool structure for invoke methods:
1043 enum {
1044   _imcp_invoke_name = 1,        // utf8: 'invokeExact', etc.
1045   _imcp_invoke_signature,       // utf8: (variable Symbol*)
1046   _imcp_limit
1047 };
1048 
1049 // Test if this method is an MH adapter frame generated by Java code.
1050 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1051 bool Method::is_compiled_lambda_form() const {
1052   return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1053 }
1054 
1055 // Test if this method is an internal MH primitive method.
1056 bool Method::is_method_handle_intrinsic() const {
1057   vmIntrinsics::ID iid = intrinsic_id();
1058   return (MethodHandles::is_signature_polymorphic(iid) &&
1059           MethodHandles::is_signature_polymorphic_intrinsic(iid));
1060 }
1061 
1062 bool Method::has_member_arg() const {
1063   vmIntrinsics::ID iid = intrinsic_id();
1064   return (MethodHandles::is_signature_polymorphic(iid) &&
1065           MethodHandles::has_member_arg(iid));
1066 }
1067 
1068 // Make an instance of a signature-polymorphic internal MH primitive.
1069 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1070                                                          Symbol* signature,
1071                                                          TRAPS) {
1072   ResourceMark rm;
1073   methodHandle empty;
1074 
1075   KlassHandle holder = SystemDictionary::MethodHandle_klass();
1076   Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1077   assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1078   if (TraceMethodHandles) {
1079     tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1080   }
1081 
1082   // invariant:   cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1083   name->increment_refcount();
1084   signature->increment_refcount();
1085 
1086   int cp_length = _imcp_limit;
1087   ClassLoaderData* loader_data = holder->class_loader_data();
1088   constantPoolHandle cp;
1089   {
1090     ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1091     cp = constantPoolHandle(THREAD, cp_oop);
1092   }
1093   cp->set_pool_holder(InstanceKlass::cast(holder()));
1094   cp->symbol_at_put(_imcp_invoke_name,       name);
1095   cp->symbol_at_put(_imcp_invoke_signature,  signature);
1096   cp->set_has_preresolution();
1097 
1098   // decide on access bits:  public or not?
1099   int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1100   bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1101   if (must_be_static)  flags_bits |= JVM_ACC_STATIC;
1102   assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1103 
1104   methodHandle m;
1105   {
1106     InlineTableSizes sizes;
1107     Method* m_oop = Method::allocate(loader_data, 0,
1108                                      accessFlags_from(flags_bits), &sizes,
1109                                      ConstMethod::NORMAL, CHECK_(empty));
1110     m = methodHandle(THREAD, m_oop);
1111   }
1112   m->set_constants(cp());
1113   m->set_name_index(_imcp_invoke_name);
1114   m->set_signature_index(_imcp_invoke_signature);
1115   assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1116   assert(m->signature() == signature, "");
1117   ResultTypeFinder rtf(signature);
1118   m->constMethod()->set_result_type(rtf.type());
1119   m->compute_size_of_parameters(THREAD);
1120   m->init_intrinsic_id();
1121   assert(m->is_method_handle_intrinsic(), "");
1122 #ifdef ASSERT
1123   if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id()))  m->print();
1124   assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1125   assert(m->intrinsic_id() == iid, "correctly predicted iid");
1126 #endif //ASSERT
1127 
1128   // Finally, set up its entry points.
1129   assert(m->can_be_statically_bound(), "");
1130   m->set_vtable_index(Method::nonvirtual_vtable_index);
1131   m->link_method(m, CHECK_(empty));
1132 
1133   if (TraceMethodHandles && (Verbose || WizardMode))
1134     m->print_on(tty);
1135 
1136   return m;
1137 }
1138 
1139 Klass* Method::check_non_bcp_klass(Klass* klass) {
1140   if (klass != NULL && klass->class_loader() != NULL) {
1141     if (klass->oop_is_objArray())
1142       klass = ObjArrayKlass::cast(klass)->bottom_klass();
1143     return klass;
1144   }
1145   return NULL;
1146 }
1147 
1148 
1149 methodHandle Method::clone_with_new_data(methodHandle m, u_char* new_code, int new_code_length,
1150                                                 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1151   // Code below does not work for native methods - they should never get rewritten anyway
1152   assert(!m->is_native(), "cannot rewrite native methods");
1153   // Allocate new Method*
1154   AccessFlags flags = m->access_flags();
1155 
1156   ConstMethod* cm = m->constMethod();
1157   int checked_exceptions_len = cm->checked_exceptions_length();
1158   int localvariable_len = cm->localvariable_table_length();
1159   int exception_table_len = cm->exception_table_length();
1160   int method_parameters_len = cm->method_parameters_length();
1161   int method_annotations_len = cm->method_annotations_length();
1162   int parameter_annotations_len = cm->parameter_annotations_length();
1163   int type_annotations_len = cm->type_annotations_length();
1164   int default_annotations_len = cm->default_annotations_length();
1165 
1166   InlineTableSizes sizes(
1167       localvariable_len,
1168       new_compressed_linenumber_size,
1169       exception_table_len,
1170       checked_exceptions_len,
1171       method_parameters_len,
1172       cm->generic_signature_index(),
1173       method_annotations_len,
1174       parameter_annotations_len,
1175       type_annotations_len,
1176       default_annotations_len,
1177       0);
1178 
1179   ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1180   Method* newm_oop = Method::allocate(loader_data,
1181                                       new_code_length,
1182                                       flags,
1183                                       &sizes,
1184                                       m->method_type(),
1185                                       CHECK_(methodHandle()));
1186   methodHandle newm (THREAD, newm_oop);
1187   int new_method_size = newm->method_size();
1188 
1189   // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1190   ConstMethod* newcm = newm->constMethod();
1191   int new_const_method_size = newm->constMethod()->size();
1192 
1193   memcpy(newm(), m(), sizeof(Method));
1194 
1195   // Create shallow copy of ConstMethod.
1196   memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1197 
1198   // Reset correct method/const method, method size, and parameter info
1199   newm->set_constMethod(newcm);
1200   newm->constMethod()->set_code_size(new_code_length);
1201   newm->constMethod()->set_constMethod_size(new_const_method_size);
1202   newm->set_method_size(new_method_size);
1203   assert(newm->code_size() == new_code_length, "check");
1204   assert(newm->method_parameters_length() == method_parameters_len, "check");
1205   assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1206   assert(newm->exception_table_length() == exception_table_len, "check");
1207   assert(newm->localvariable_table_length() == localvariable_len, "check");
1208   // Copy new byte codes
1209   memcpy(newm->code_base(), new_code, new_code_length);
1210   // Copy line number table
1211   if (new_compressed_linenumber_size > 0) {
1212     memcpy(newm->compressed_linenumber_table(),
1213            new_compressed_linenumber_table,
1214            new_compressed_linenumber_size);
1215   }
1216   // Copy method_parameters
1217   if (method_parameters_len > 0) {
1218     memcpy(newm->method_parameters_start(),
1219            m->method_parameters_start(),
1220            method_parameters_len * sizeof(MethodParametersElement));
1221   }
1222   // Copy checked_exceptions
1223   if (checked_exceptions_len > 0) {
1224     memcpy(newm->checked_exceptions_start(),
1225            m->checked_exceptions_start(),
1226            checked_exceptions_len * sizeof(CheckedExceptionElement));
1227   }
1228   // Copy exception table
1229   if (exception_table_len > 0) {
1230     memcpy(newm->exception_table_start(),
1231            m->exception_table_start(),
1232            exception_table_len * sizeof(ExceptionTableElement));
1233   }
1234   // Copy local variable number table
1235   if (localvariable_len > 0) {
1236     memcpy(newm->localvariable_table_start(),
1237            m->localvariable_table_start(),
1238            localvariable_len * sizeof(LocalVariableTableElement));
1239   }
1240   // Copy stackmap table
1241   if (m->has_stackmap_table()) {
1242     int code_attribute_length = m->stackmap_data()->length();
1243     Array<u1>* stackmap_data =
1244       MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1245     memcpy((void*)stackmap_data->adr_at(0),
1246            (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1247     newm->set_stackmap_data(stackmap_data);
1248   }
1249 
1250   // copy annotations over to new method
1251   newcm->copy_annotations_from(cm);
1252   return newm;
1253 }
1254 
1255 vmSymbols::SID Method::klass_id_for_intrinsics(Klass* holder) {
1256   // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1257   // because we are not loading from core libraries
1258   // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1259   // which does not use the class default class loader so we check for its loader here
1260   InstanceKlass* ik = InstanceKlass::cast(holder);
1261   if ((ik->class_loader() != NULL) && !SystemDictionary::is_ext_class_loader(ik->class_loader())) {
1262     return vmSymbols::NO_SID;   // regardless of name, no intrinsics here
1263   }
1264 
1265   // see if the klass name is well-known:
1266   Symbol* klass_name = ik->name();
1267   return vmSymbols::find_sid(klass_name);
1268 }
1269 
1270 void Method::init_intrinsic_id() {
1271   assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1272   const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1273   assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1274   assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1275 
1276   // the klass name is well-known:
1277   vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1278   assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1279 
1280   // ditto for method and signature:
1281   vmSymbols::SID  name_id = vmSymbols::find_sid(name());
1282   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1283       && name_id == vmSymbols::NO_SID)
1284     return;
1285   vmSymbols::SID   sig_id = vmSymbols::find_sid(signature());
1286   if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1287       && sig_id == vmSymbols::NO_SID)  return;
1288   jshort flags = access_flags().as_short();
1289 
1290   vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1291   if (id != vmIntrinsics::_none) {
1292     set_intrinsic_id(id);
1293     return;
1294   }
1295 
1296   // A few slightly irregular cases:
1297   switch (klass_id) {
1298   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1299     // Second chance: check in regular Math.
1300     switch (name_id) {
1301     case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1302     case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1303     case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1304       // pretend it is the corresponding method in the non-strict class:
1305       klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1306       id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1307       break;
1308     }
1309     break;
1310 
1311   // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*.
1312   case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1313     if (!is_native())  break;
1314     id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1315     if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1316       id = vmIntrinsics::_none;
1317     break;
1318   }
1319 
1320   if (id != vmIntrinsics::_none) {
1321     // Set up its iid.  It is an alias method.
1322     set_intrinsic_id(id);
1323     return;
1324   }
1325 }
1326 
1327 // These two methods are static since a GC may move the Method
1328 bool Method::load_signature_classes(methodHandle m, TRAPS) {
1329   if (THREAD->is_Compiler_thread()) {
1330     // There is nothing useful this routine can do from within the Compile thread.
1331     // Hopefully, the signature contains only well-known classes.
1332     // We could scan for this and return true/false, but the caller won't care.
1333     return false;
1334   }
1335   bool sig_is_loaded = true;
1336   Handle class_loader(THREAD, m->method_holder()->class_loader());
1337   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1338   ResourceMark rm(THREAD);
1339   Symbol*  signature = m->signature();
1340   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1341     if (ss.is_object()) {
1342       Symbol* sym = ss.as_symbol(CHECK_(false));
1343       Symbol*  name  = sym;
1344       Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1345                                              protection_domain, THREAD);
1346       // We are loading classes eagerly. If a ClassNotFoundException or
1347       // a LinkageError was generated, be sure to ignore it.
1348       if (HAS_PENDING_EXCEPTION) {
1349         if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1350             PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1351           CLEAR_PENDING_EXCEPTION;
1352         } else {
1353           return false;
1354         }
1355       }
1356       if( klass == NULL) { sig_is_loaded = false; }
1357     }
1358   }
1359   return sig_is_loaded;
1360 }
1361 
1362 bool Method::has_unloaded_classes_in_signature(methodHandle m, TRAPS) {
1363   Handle class_loader(THREAD, m->method_holder()->class_loader());
1364   Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1365   ResourceMark rm(THREAD);
1366   Symbol*  signature = m->signature();
1367   for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1368     if (ss.type() == T_OBJECT) {
1369       Symbol* name = ss.as_symbol_or_null();
1370       if (name == NULL) return true;
1371       Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1372       if (klass == NULL) return true;
1373     }
1374   }
1375   return false;
1376 }
1377 
1378 // Exposed so field engineers can debug VM
1379 void Method::print_short_name(outputStream* st) {
1380   ResourceMark rm;
1381 #ifdef PRODUCT
1382   st->print(" %s::", method_holder()->external_name());
1383 #else
1384   st->print(" %s::", method_holder()->internal_name());
1385 #endif
1386   name()->print_symbol_on(st);
1387   if (WizardMode) signature()->print_symbol_on(st);
1388   else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1389     MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1390 }
1391 
1392 // Comparer for sorting an object array containing
1393 // Method*s.
1394 static int method_comparator(Method* a, Method* b) {
1395   return a->name()->fast_compare(b->name());
1396 }
1397 
1398 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1399 // default_methods also uses this without the ordering for fast find_method
1400 void Method::sort_methods(Array<Method*>* methods, bool idempotent, bool set_idnums) {
1401   int length = methods->length();
1402   if (length > 1) {
1403     {
1404       No_Safepoint_Verifier nsv;
1405       QuickSort::sort<Method*>(methods->data(), length, method_comparator, idempotent);
1406     }
1407     // Reset method ordering
1408     if (set_idnums) {
1409       for (int i = 0; i < length; i++) {
1410         Method* m = methods->at(i);
1411         m->set_method_idnum(i);
1412         m->set_orig_method_idnum(i);
1413       }
1414     }
1415   }
1416 }
1417 
1418 //-----------------------------------------------------------------------------------
1419 // Non-product code unless JVM/TI needs it
1420 
1421 #if !defined(PRODUCT) || INCLUDE_JVMTI
1422 class SignatureTypePrinter : public SignatureTypeNames {
1423  private:
1424   outputStream* _st;
1425   bool _use_separator;
1426 
1427   void type_name(const char* name) {
1428     if (_use_separator) _st->print(", ");
1429     _st->print("%s", name);
1430     _use_separator = true;
1431   }
1432 
1433  public:
1434   SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1435     _st = st;
1436     _use_separator = false;
1437   }
1438 
1439   void print_parameters()              { _use_separator = false; iterate_parameters(); }
1440   void print_returntype()              { _use_separator = false; iterate_returntype(); }
1441 };
1442 
1443 
1444 void Method::print_name(outputStream* st) {
1445   Thread *thread = Thread::current();
1446   ResourceMark rm(thread);
1447   SignatureTypePrinter sig(signature(), st);
1448   st->print("%s ", is_static() ? "static" : "virtual");
1449   sig.print_returntype();
1450   st->print(" %s.", method_holder()->internal_name());
1451   name()->print_symbol_on(st);
1452   st->print("(");
1453   sig.print_parameters();
1454   st->print(")");
1455 }
1456 #endif // !PRODUCT || INCLUDE_JVMTI
1457 
1458 
1459 //-----------------------------------------------------------------------------------
1460 // Non-product code
1461 
1462 #ifndef PRODUCT
1463 void Method::print_codes_on(outputStream* st) const {
1464   print_codes_on(0, code_size(), st);
1465 }
1466 
1467 void Method::print_codes_on(int from, int to, outputStream* st) const {
1468   Thread *thread = Thread::current();
1469   ResourceMark rm(thread);
1470   methodHandle mh (thread, (Method*)this);
1471   BytecodeStream s(mh);
1472   s.set_interval(from, to);
1473   BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1474   while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1475 }
1476 #endif // not PRODUCT
1477 
1478 
1479 // Simple compression of line number tables. We use a regular compressed stream, except that we compress deltas
1480 // between (bci,line) pairs since they are smaller. If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
1481 // we save it as one byte, otherwise we write a 0xFF escape character and use regular compression. 0x0 is used
1482 // as end-of-stream terminator.
1483 
1484 void CompressedLineNumberWriteStream::write_pair_regular(int bci_delta, int line_delta) {
1485   // bci and line number does not compress into single byte.
1486   // Write out escape character and use regular compression for bci and line number.
1487   write_byte((jubyte)0xFF);
1488   write_signed_int(bci_delta);
1489   write_signed_int(line_delta);
1490 }
1491 
1492 // See comment in method.hpp which explains why this exists.
1493 #if defined(_M_AMD64) && _MSC_VER >= 1400
1494 #pragma optimize("", off)
1495 void CompressedLineNumberWriteStream::write_pair(int bci, int line) {
1496   write_pair_inline(bci, line);
1497 }
1498 #pragma optimize("", on)
1499 #endif
1500 
1501 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1502   _bci = 0;
1503   _line = 0;
1504 };
1505 
1506 
1507 bool CompressedLineNumberReadStream::read_pair() {
1508   jubyte next = read_byte();
1509   // Check for terminator
1510   if (next == 0) return false;
1511   if (next == 0xFF) {
1512     // Escape character, regular compression used
1513     _bci  += read_signed_int();
1514     _line += read_signed_int();
1515   } else {
1516     // Single byte compression used
1517     _bci  += next >> 3;
1518     _line += next & 0x7;
1519   }
1520   return true;
1521 }
1522 
1523 
1524 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1525   BreakpointInfo* bp = method_holder()->breakpoints();
1526   for (; bp != NULL; bp = bp->next()) {
1527     if (bp->match(this, bci)) {
1528       return bp->orig_bytecode();
1529     }
1530   }
1531   {
1532     ResourceMark rm;
1533     fatal(err_msg("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci));
1534   }
1535   return Bytecodes::_shouldnotreachhere;
1536 }
1537 
1538 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1539   assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1540   BreakpointInfo* bp = method_holder()->breakpoints();
1541   for (; bp != NULL; bp = bp->next()) {
1542     if (bp->match(this, bci)) {
1543       bp->set_orig_bytecode(code);
1544       // and continue, in case there is more than one
1545     }
1546   }
1547 }
1548 
1549 void Method::set_breakpoint(int bci) {
1550   InstanceKlass* ik = method_holder();
1551   BreakpointInfo *bp = new BreakpointInfo(this, bci);
1552   bp->set_next(ik->breakpoints());
1553   ik->set_breakpoints(bp);
1554   // do this last:
1555   bp->set(this);
1556 }
1557 
1558 static void clear_matches(Method* m, int bci) {
1559   InstanceKlass* ik = m->method_holder();
1560   BreakpointInfo* prev_bp = NULL;
1561   BreakpointInfo* next_bp;
1562   for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1563     next_bp = bp->next();
1564     // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1565     if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1566       // do this first:
1567       bp->clear(m);
1568       // unhook it
1569       if (prev_bp != NULL)
1570         prev_bp->set_next(next_bp);
1571       else
1572         ik->set_breakpoints(next_bp);
1573       delete bp;
1574       // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1575       // at same location. So we have multiple matching (method_index and bci)
1576       // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1577       // breakpoint for clear_breakpoint request and keep all other method versions
1578       // BreakpointInfo for future clear_breakpoint request.
1579       // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1580       // which is being called when class is unloaded. We delete all the Breakpoint
1581       // information for all versions of method. We may not correctly restore the original
1582       // bytecode in all method versions, but that is ok. Because the class is being unloaded
1583       // so these methods won't be used anymore.
1584       if (bci >= 0) {
1585         break;
1586       }
1587     } else {
1588       // This one is a keeper.
1589       prev_bp = bp;
1590     }
1591   }
1592 }
1593 
1594 void Method::clear_breakpoint(int bci) {
1595   assert(bci >= 0, "");
1596   clear_matches(this, bci);
1597 }
1598 
1599 void Method::clear_all_breakpoints() {
1600   clear_matches(this, -1);
1601 }
1602 
1603 
1604 int Method::invocation_count() {
1605   MethodCounters *mcs = method_counters();
1606   if (TieredCompilation) {
1607     MethodData* const mdo = method_data();
1608     if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1609         ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1610       return InvocationCounter::count_limit;
1611     } else {
1612       return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1613              ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1614     }
1615   } else {
1616     return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1617   }
1618 }
1619 
1620 int Method::backedge_count() {
1621   MethodCounters *mcs = method_counters();
1622   if (TieredCompilation) {
1623     MethodData* const mdo = method_data();
1624     if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1625         ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1626       return InvocationCounter::count_limit;
1627     } else {
1628       return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1629              ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1630     }
1631   } else {
1632     return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1633   }
1634 }
1635 
1636 int Method::highest_comp_level() const {
1637   const MethodCounters* mcs = method_counters();
1638   if (mcs != NULL) {
1639     return mcs->highest_comp_level();
1640   } else {
1641     return CompLevel_none;
1642   }
1643 }
1644 
1645 int Method::highest_osr_comp_level() const {
1646   const MethodCounters* mcs = method_counters();
1647   if (mcs != NULL) {
1648     return mcs->highest_osr_comp_level();
1649   } else {
1650     return CompLevel_none;
1651   }
1652 }
1653 
1654 void Method::set_highest_comp_level(int level) {
1655   MethodCounters* mcs = method_counters();
1656   if (mcs != NULL) {
1657     mcs->set_highest_comp_level(level);
1658   }
1659 }
1660 
1661 void Method::set_highest_osr_comp_level(int level) {
1662   MethodCounters* mcs = method_counters();
1663   if (mcs != NULL) {
1664     mcs->set_highest_osr_comp_level(level);
1665   }
1666 }
1667 
1668 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1669   _bci = bci;
1670   _name_index = m->name_index();
1671   _signature_index = m->signature_index();
1672   _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1673   if (_orig_bytecode == Bytecodes::_breakpoint)
1674     _orig_bytecode = m->orig_bytecode_at(_bci);
1675   _next = NULL;
1676 }
1677 
1678 void BreakpointInfo::set(Method* method) {
1679 #ifdef ASSERT
1680   {
1681     Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
1682     if (code == Bytecodes::_breakpoint)
1683       code = method->orig_bytecode_at(_bci);
1684     assert(orig_bytecode() == code, "original bytecode must be the same");
1685   }
1686 #endif
1687   Thread *thread = Thread::current();
1688   *method->bcp_from(_bci) = Bytecodes::_breakpoint;
1689   method->incr_number_of_breakpoints(thread);
1690   SystemDictionary::notice_modification();
1691   {
1692     // Deoptimize all dependents on this method
1693     HandleMark hm(thread);
1694     methodHandle mh(thread, method);
1695     Universe::flush_dependents_on_method(mh);
1696   }
1697 }
1698 
1699 void BreakpointInfo::clear(Method* method) {
1700   *method->bcp_from(_bci) = orig_bytecode();
1701   assert(method->number_of_breakpoints() > 0, "must not go negative");
1702   method->decr_number_of_breakpoints(Thread::current());
1703 }
1704 
1705 // jmethodID handling
1706 
1707 // This is a block allocating object, sort of like JNIHandleBlock, only a
1708 // lot simpler.  There aren't many of these, they aren't long, they are rarely
1709 // deleted and so we can do some suboptimal things.
1710 // It's allocated on the CHeap because once we allocate a jmethodID, we can
1711 // never get rid of it.
1712 // It would be nice to be able to parameterize the number of methods for
1713 // the null_class_loader but then we'd have to turn this and ClassLoaderData
1714 // into templates.
1715 
1716 // I feel like this brain dead class should exist somewhere in the STL
1717 
1718 class JNIMethodBlock : public CHeapObj<mtClass> {
1719   enum { number_of_methods = 8 };
1720 
1721   Method*         _methods[number_of_methods];
1722   int             _top;
1723   JNIMethodBlock* _next;
1724  public:
1725   static Method* const _free_method;
1726 
1727   JNIMethodBlock() : _next(NULL), _top(0) {
1728     for (int i = 0; i< number_of_methods; i++) _methods[i] = _free_method;
1729   }
1730 
1731   Method** add_method(Method* m) {
1732     if (_top < number_of_methods) {
1733       // top points to the next free entry.
1734       int i = _top;
1735       _methods[i] = m;
1736       _top++;
1737       return &_methods[i];
1738     } else if (_top == number_of_methods) {
1739       // if the next free entry ran off the block see if there's a free entry
1740       for (int i = 0; i< number_of_methods; i++) {
1741         if (_methods[i] == _free_method) {
1742           _methods[i] = m;
1743           return &_methods[i];
1744         }
1745       }
1746       // Only check each block once for frees.  They're very unlikely.
1747       // Increment top past the end of the block.
1748       _top++;
1749     }
1750     // need to allocate a next block.
1751     if (_next == NULL) {
1752       _next = new JNIMethodBlock();
1753     }
1754     return _next->add_method(m);
1755   }
1756 
1757   bool contains(Method** m) {
1758     for (JNIMethodBlock* b = this; b != NULL; b = b->_next) {
1759       for (int i = 0; i< number_of_methods; i++) {
1760         if (&(b->_methods[i]) == m) {
1761           return true;
1762         }
1763       }
1764     }
1765     return false;  // not found
1766   }
1767 
1768   // Doesn't really destroy it, just marks it as free so it can be reused.
1769   void destroy_method(Method** m) {
1770 #ifdef ASSERT
1771     assert(contains(m), "should be a methodID");
1772 #endif // ASSERT
1773     *m = _free_method;
1774   }
1775 
1776   // During class unloading the methods are cleared, which is different
1777   // than freed.
1778   void clear_all_methods() {
1779     for (JNIMethodBlock* b = this; b != NULL; b = b->_next) {
1780       for (int i = 0; i< number_of_methods; i++) {
1781         b->_methods[i] = NULL;
1782       }
1783     }
1784   }
1785 #ifndef PRODUCT
1786   int count_methods() {
1787     // count all allocated methods
1788     int count = 0;
1789     for (JNIMethodBlock* b = this; b != NULL; b = b->_next) {
1790       for (int i = 0; i< number_of_methods; i++) {
1791         if (b->_methods[i] != _free_method) count++;
1792       }
1793     }
1794     return count;
1795   }
1796 #endif // PRODUCT
1797 };
1798 
1799 // Something that can't be mistaken for an address or a markOop
1800 Method* const JNIMethodBlock::_free_method = (Method*)55;
1801 
1802 // Add a method id to the jmethod_ids
1803 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
1804   ClassLoaderData* cld = loader_data;
1805 
1806   if (!SafepointSynchronize::is_at_safepoint()) {
1807     // Have to add jmethod_ids() to class loader data thread-safely.
1808     // Also have to add the method to the list safely, which the cld lock
1809     // protects as well.
1810     MutexLockerEx ml(cld->metaspace_lock(),  Mutex::_no_safepoint_check_flag);
1811     if (cld->jmethod_ids() == NULL) {
1812       cld->set_jmethod_ids(new JNIMethodBlock());
1813     }
1814     // jmethodID is a pointer to Method*
1815     return (jmethodID)cld->jmethod_ids()->add_method(m);
1816   } else {
1817     // At safepoint, we are single threaded and can set this.
1818     if (cld->jmethod_ids() == NULL) {
1819       cld->set_jmethod_ids(new JNIMethodBlock());
1820     }
1821     // jmethodID is a pointer to Method*
1822     return (jmethodID)cld->jmethod_ids()->add_method(m);
1823   }
1824 }
1825 
1826 // Mark a jmethodID as free.  This is called when there is a data race in
1827 // InstanceKlass while creating the jmethodID cache.
1828 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
1829   ClassLoaderData* cld = loader_data;
1830   Method** ptr = (Method**)m;
1831   assert(cld->jmethod_ids() != NULL, "should have method handles");
1832   cld->jmethod_ids()->destroy_method(ptr);
1833 }
1834 
1835 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
1836   // Can't assert the method_holder is the same because the new method has the
1837   // scratch method holder.
1838   assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
1839            == new_method->method_holder()->class_loader(),
1840          "changing to a different class loader");
1841   // Just change the method in place, jmethodID pointer doesn't change.
1842   *((Method**)jmid) = new_method;
1843 }
1844 
1845 bool Method::is_method_id(jmethodID mid) {
1846   Method* m = resolve_jmethod_id(mid);
1847   assert(m != NULL, "should be called with non-null method");
1848   InstanceKlass* ik = m->method_holder();
1849   if (ik == NULL) {
1850     return false;
1851   }
1852   ClassLoaderData* cld = ik->class_loader_data();
1853   if (cld->jmethod_ids() == NULL) return false;
1854   return (cld->jmethod_ids()->contains((Method**)mid));
1855 }
1856 
1857 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
1858   if (mid == NULL) return NULL;
1859   if (!Method::is_method_id(mid)) {
1860     return NULL;
1861   }
1862   Method* o = resolve_jmethod_id(mid);
1863   if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
1864     return NULL;
1865   }
1866   return o;
1867 };
1868 
1869 void Method::set_on_stack(const bool value) {
1870   // Set both the method itself and its constant pool.  The constant pool
1871   // on stack means some method referring to it is also on the stack.
1872   constants()->set_on_stack(value);
1873 
1874   bool succeeded = _access_flags.set_on_stack(value);
1875   if (value && succeeded) {
1876     MetadataOnStackMark::record(this, Thread::current());
1877   }
1878 }
1879 
1880 // Called when the class loader is unloaded to make all methods weak.
1881 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
1882   loader_data->jmethod_ids()->clear_all_methods();
1883 }
1884 
1885 bool Method::has_method_vptr(const void* ptr) {
1886   Method m;
1887   // This assumes that the vtbl pointer is the first word of a C++ object.
1888   // This assumption is also in universe.cpp patch_klass_vtble
1889   void* vtbl2 = dereference_vptr((const void*)&m);
1890   void* this_vtbl = dereference_vptr(ptr);
1891   return vtbl2 == this_vtbl;
1892 }
1893 
1894 // Check that this pointer is valid by checking that the vtbl pointer matches
1895 bool Method::is_valid_method() const {
1896   if (this == NULL) {
1897     return false;
1898   } else if (!is_metaspace_object()) {
1899     return false;
1900   } else {
1901     return has_method_vptr((const void*)this);
1902   }
1903 }
1904 
1905 #ifndef PRODUCT
1906 void Method::print_jmethod_ids(ClassLoaderData* loader_data, outputStream* out) {
1907   out->print_cr("jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
1908 }
1909 #endif // PRODUCT
1910 
1911 
1912 // Printing
1913 
1914 #ifndef PRODUCT
1915 
1916 void Method::print_on(outputStream* st) const {
1917   ResourceMark rm;
1918   assert(is_method(), "must be method");
1919   st->print_cr("%s", internal_name());
1920   // get the effect of PrintOopAddress, always, for methods:
1921   st->print_cr(" - this oop:          "INTPTR_FORMAT, (intptr_t)this);
1922   st->print   (" - method holder:     "); method_holder()->print_value_on(st); st->cr();
1923   st->print   (" - constants:         "INTPTR_FORMAT" ", (address)constants());
1924   constants()->print_value_on(st); st->cr();
1925   st->print   (" - access:            0x%x  ", access_flags().as_int()); access_flags().print_on(st); st->cr();
1926   st->print   (" - name:              ");    name()->print_value_on(st); st->cr();
1927   st->print   (" - signature:         ");    signature()->print_value_on(st); st->cr();
1928   st->print_cr(" - max stack:         %d",   max_stack());
1929   st->print_cr(" - max locals:        %d",   max_locals());
1930   st->print_cr(" - size of params:    %d",   size_of_parameters());
1931   st->print_cr(" - method size:       %d",   method_size());
1932   if (intrinsic_id() != vmIntrinsics::_none)
1933     st->print_cr(" - intrinsic id:      %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
1934   if (highest_comp_level() != CompLevel_none)
1935     st->print_cr(" - highest level:     %d", highest_comp_level());
1936   st->print_cr(" - vtable index:      %d",   _vtable_index);
1937   st->print_cr(" - i2i entry:         " INTPTR_FORMAT, interpreter_entry());
1938   st->print(   " - adapters:          ");
1939   AdapterHandlerEntry* a = ((Method*)this)->adapter();
1940   if (a == NULL)
1941     st->print_cr(INTPTR_FORMAT, a);
1942   else
1943     a->print_adapter_on(st);
1944   st->print_cr(" - compiled entry     " INTPTR_FORMAT, from_compiled_entry());
1945   st->print_cr(" - code size:         %d",   code_size());
1946   if (code_size() != 0) {
1947     st->print_cr(" - code start:        " INTPTR_FORMAT, code_base());
1948     st->print_cr(" - code end (excl):   " INTPTR_FORMAT, code_base() + code_size());
1949   }
1950   if (method_data() != NULL) {
1951     st->print_cr(" - method data:       " INTPTR_FORMAT, (address)method_data());
1952   }
1953   st->print_cr(" - checked ex length: %d",   checked_exceptions_length());
1954   if (checked_exceptions_length() > 0) {
1955     CheckedExceptionElement* table = checked_exceptions_start();
1956     st->print_cr(" - checked ex start:  " INTPTR_FORMAT, table);
1957     if (Verbose) {
1958       for (int i = 0; i < checked_exceptions_length(); i++) {
1959         st->print_cr("   - throws %s", constants()->printable_name_at(table[i].class_cp_index));
1960       }
1961     }
1962   }
1963   if (has_linenumber_table()) {
1964     u_char* table = compressed_linenumber_table();
1965     st->print_cr(" - linenumber start:  " INTPTR_FORMAT, table);
1966     if (Verbose) {
1967       CompressedLineNumberReadStream stream(table);
1968       while (stream.read_pair()) {
1969         st->print_cr("   - line %d: %d", stream.line(), stream.bci());
1970       }
1971     }
1972   }
1973   st->print_cr(" - localvar length:   %d",   localvariable_table_length());
1974   if (localvariable_table_length() > 0) {
1975     LocalVariableTableElement* table = localvariable_table_start();
1976     st->print_cr(" - localvar start:    " INTPTR_FORMAT, table);
1977     if (Verbose) {
1978       for (int i = 0; i < localvariable_table_length(); i++) {
1979         int bci = table[i].start_bci;
1980         int len = table[i].length;
1981         const char* name = constants()->printable_name_at(table[i].name_cp_index);
1982         const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
1983         int slot = table[i].slot;
1984         st->print_cr("   - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
1985       }
1986     }
1987   }
1988   if (code() != NULL) {
1989     st->print   (" - compiled code: ");
1990     code()->print_value_on(st);
1991   }
1992   if (is_native()) {
1993     st->print_cr(" - native function:   " INTPTR_FORMAT, native_function());
1994     st->print_cr(" - signature handler: " INTPTR_FORMAT, signature_handler());
1995   }
1996 }
1997 
1998 #endif //PRODUCT
1999 
2000 void Method::print_value_on(outputStream* st) const {
2001   assert(is_method(), "must be method");
2002   st->print("%s", internal_name());
2003   print_address_on(st);
2004   st->print(" ");
2005   name()->print_value_on(st);
2006   st->print(" ");
2007   signature()->print_value_on(st);
2008   st->print(" in ");
2009   method_holder()->print_value_on(st);
2010   if (WizardMode) st->print("#%d", _vtable_index);
2011   if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2012   if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2013 }
2014 
2015 #if INCLUDE_SERVICES
2016 // Size Statistics
2017 void Method::collect_statistics(KlassSizeStats *sz) const {
2018   int mysize = sz->count(this);
2019   sz->_method_bytes += mysize;
2020   sz->_method_all_bytes += mysize;
2021   sz->_rw_bytes += mysize;
2022 
2023   if (constMethod()) {
2024     constMethod()->collect_statistics(sz);
2025   }
2026   if (method_data()) {
2027     method_data()->collect_statistics(sz);
2028   }
2029 }
2030 #endif // INCLUDE_SERVICES
2031 
2032 // Verification
2033 
2034 void Method::verify_on(outputStream* st) {
2035   guarantee(is_method(), "object must be method");
2036   guarantee(constants()->is_constantPool(), "should be constant pool");
2037   guarantee(constMethod()->is_constMethod(), "should be ConstMethod*");
2038   MethodData* md = method_data();
2039   guarantee(md == NULL ||
2040       md->is_methodData(), "should be method data");
2041 }