1 /*
   2  * Copyright (c) 1998, 2013, 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 "gc_implementation/shared/markSweep.inline.hpp"
  27 #include "interpreter/interpreter.hpp"
  28 #include "interpreter/rewriter.hpp"
  29 #include "memory/universe.inline.hpp"
  30 #include "oops/cpCache.hpp"
  31 #include "oops/objArrayOop.hpp"
  32 #include "oops/oop.inline.hpp"
  33 #include "prims/jvmtiRedefineClassesTrace.hpp"
  34 #include "prims/methodHandles.hpp"
  35 #include "runtime/handles.inline.hpp"
  36 #ifndef SERIALGC
  37 # include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
  38 #endif
  39 
  40 
  41 // Implememtation of ConstantPoolCacheEntry
  42 
  43 void ConstantPoolCacheEntry::initialize_entry(int index) {
  44   assert(0 < index && index < 0x10000, "sanity check");
  45   _indices = index;
  46   assert(constant_pool_index() == index, "");
  47 }
  48 
  49 int ConstantPoolCacheEntry::make_flags(TosState state,
  50                                        int option_bits,
  51                                        int field_index_or_method_params) {
  52   assert(state < number_of_states, "Invalid state in make_flags");
  53   int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params;
  54   // Preserve existing flag bit values
  55   // The low bits are a field offset, or else the method parameter size.
  56 #ifdef ASSERT
  57   TosState old_state = flag_state();
  58   assert(old_state == (TosState)0 || old_state == state,
  59          "inconsistent cpCache flags state");
  60 #endif
  61   return (_flags | f) ;
  62 }
  63 
  64 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) {
  65 #ifdef ASSERT
  66   // Read once.
  67   volatile Bytecodes::Code c = bytecode_1();
  68   assert(c == 0 || c == code || code == 0, "update must be consistent");
  69 #endif
  70   // Need to flush pending stores here before bytecode is written.
  71   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_1_shift));
  72 }
  73 
  74 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {
  75 #ifdef ASSERT
  76   // Read once.
  77   volatile Bytecodes::Code c = bytecode_2();
  78   assert(c == 0 || c == code || code == 0, "update must be consistent");
  79 #endif
  80   // Need to flush pending stores here before bytecode is written.
  81   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_2_shift));
  82 }
  83 
  84 // Sets f1, ordering with previous writes.
  85 void ConstantPoolCacheEntry::release_set_f1(Metadata* f1) {
  86   assert(f1 != NULL, "");
  87   OrderAccess::release_store_ptr((HeapWord*) &_f1, f1);
  88 }
  89 
  90 // Sets flags, but only if the value was previously zero.
  91 bool ConstantPoolCacheEntry::init_flags_atomic(intptr_t flags) {
  92   intptr_t result = Atomic::cmpxchg_ptr(flags, &_flags, 0);
  93   return (result == 0);
  94 }
  95 
  96 // Note that concurrent update of both bytecodes can leave one of them
  97 // reset to zero.  This is harmless; the interpreter will simply re-resolve
  98 // the damaged entry.  More seriously, the memory synchronization is needed
  99 // to flush other fields (f1, f2) completely to memory before the bytecodes
 100 // are updated, lest other processors see a non-zero bytecode but zero f1/f2.
 101 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code,
 102                                        Bytecodes::Code put_code,
 103                                        KlassHandle field_holder,
 104                                        int field_index,
 105                                        int field_offset,
 106                                        TosState field_type,
 107                                        bool is_final,
 108                                        bool is_volatile,
 109                                        Klass* root_klass) {
 110   set_f1(field_holder());
 111   set_f2(field_offset);
 112   assert((field_index & field_index_mask) == field_index,
 113          "field index does not fit in low flag bits");
 114   set_field_flags(field_type,
 115                   ((is_volatile ? 1 : 0) << is_volatile_shift) |
 116                   ((is_final    ? 1 : 0) << is_final_shift),
 117                   field_index);
 118   set_bytecode_1(get_code);
 119   set_bytecode_2(put_code);
 120   NOT_PRODUCT(verify(tty));
 121 }
 122 
 123 void ConstantPoolCacheEntry::set_parameter_size(int value) {
 124   // This routine is called only in corner cases where the CPCE is not yet initialized.
 125   // See AbstractInterpreter::deopt_continue_after_entry.
 126   assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value,
 127          err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value));
 128   // Setting the parameter size by itself is only safe if the
 129   // current value of _flags is 0, otherwise another thread may have
 130   // updated it and we don't want to overwrite that value.  Don't
 131   // bother trying to update it once it's nonzero but always make
 132   // sure that the final parameter size agrees with what was passed.
 133   if (_flags == 0) {
 134     Atomic::cmpxchg_ptr((value & parameter_size_mask), &_flags, 0);
 135   }
 136   guarantee(parameter_size() == value,
 137             err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value));
 138 }
 139 
 140 void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,
 141                                         methodHandle method,
 142                                         int vtable_index) {
 143   assert(method->interpreter_entry() != NULL, "should have been set at this point");
 144   assert(!method->is_obsolete(),  "attempt to write obsolete method to cpCache");
 145 
 146   int byte_no = -1;
 147   bool change_to_virtual = false;
 148 
 149   switch (invoke_code) {
 150     case Bytecodes::_invokeinterface:
 151       // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface
 152       // instruction somehow links to a non-interface method (in Object).
 153       // In that case, the method has no itable index and must be invoked as a virtual.
 154       // Set a flag to keep track of this corner case.
 155       change_to_virtual = true;
 156 
 157       // ...and fall through as if we were handling invokevirtual:
 158     case Bytecodes::_invokevirtual:
 159       {
 160         if (method->can_be_statically_bound()) {
 161           // set_f2_as_vfinal_method checks if is_vfinal flag is true.
 162           set_method_flags(as_TosState(method->result_type()),
 163                            (                             1      << is_vfinal_shift) |
 164                            ((method->is_final_method() ? 1 : 0) << is_final_shift)  |
 165                            ((change_to_virtual         ? 1 : 0) << is_forced_virtual_shift),
 166                            method()->size_of_parameters());
 167           set_f2_as_vfinal_method(method());
 168         } else {
 169           assert(vtable_index >= 0, "valid index");
 170           assert(!method->is_final_method(), "sanity");
 171           set_method_flags(as_TosState(method->result_type()),
 172                            ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
 173                            method()->size_of_parameters());
 174           set_f2(vtable_index);
 175         }
 176         byte_no = 2;
 177         break;
 178       }
 179 
 180     case Bytecodes::_invokespecial:
 181     case Bytecodes::_invokestatic:
 182       // Note:  Read and preserve the value of the is_vfinal flag on any
 183       // invokevirtual bytecode shared with this constant pool cache entry.
 184       // It is cheap and safe to consult is_vfinal() at all times.
 185       // Once is_vfinal is set, it must stay that way, lest we get a dangling oop.
 186       set_method_flags(as_TosState(method->result_type()),
 187                        ((is_vfinal()               ? 1 : 0) << is_vfinal_shift) |
 188                        ((method->is_final_method() ? 1 : 0) << is_final_shift),
 189                        method()->size_of_parameters());
 190       set_f1(method());
 191       byte_no = 1;
 192       break;
 193     default:
 194       ShouldNotReachHere();
 195       break;
 196   }
 197 
 198   // Note:  byte_no also appears in TemplateTable::resolve.
 199   if (byte_no == 1) {
 200     assert(invoke_code != Bytecodes::_invokevirtual &&
 201            invoke_code != Bytecodes::_invokeinterface, "");
 202     set_bytecode_1(invoke_code);
 203   } else if (byte_no == 2)  {
 204     if (change_to_virtual) {
 205       assert(invoke_code == Bytecodes::_invokeinterface, "");
 206       // NOTE: THIS IS A HACK - BE VERY CAREFUL!!!
 207       //
 208       // Workaround for the case where we encounter an invokeinterface, but we
 209       // should really have an _invokevirtual since the resolved method is a
 210       // virtual method in java.lang.Object. This is a corner case in the spec
 211       // but is presumably legal. javac does not generate this code.
 212       //
 213       // We set bytecode_1() to _invokeinterface, because that is the
 214       // bytecode # used by the interpreter to see if it is resolved.
 215       // We set bytecode_2() to _invokevirtual.
 216       // See also interpreterRuntime.cpp. (8/25/2000)
 217       // Only set resolved for the invokeinterface case if method is public.
 218       // Otherwise, the method needs to be reresolved with caller for each
 219       // interface call.
 220       if (method->is_public()) set_bytecode_1(invoke_code);
 221     } else {
 222       assert(invoke_code == Bytecodes::_invokevirtual, "");
 223     }
 224     // set up for invokevirtual, even if linking for invokeinterface also:
 225     set_bytecode_2(Bytecodes::_invokevirtual);
 226   } else {
 227     ShouldNotReachHere();
 228   }
 229   NOT_PRODUCT(verify(tty));
 230 }
 231 
 232 
 233 void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) {
 234   InstanceKlass* interf = method->method_holder();
 235   assert(interf->is_interface(), "must be an interface");
 236   assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");
 237   set_f1(interf);
 238   set_f2(index);
 239   set_method_flags(as_TosState(method->result_type()),
 240                    0,  // no option bits
 241                    method()->size_of_parameters());
 242   set_bytecode_1(Bytecodes::_invokeinterface);
 243 }
 244 
 245 
 246 void ConstantPoolCacheEntry::set_method_handle(constantPoolHandle cpool, const CallInfo &call_info) {
 247   set_method_handle_common(cpool, Bytecodes::_invokehandle, call_info);
 248 }
 249 
 250 void ConstantPoolCacheEntry::set_dynamic_call(constantPoolHandle cpool, const CallInfo &call_info) {
 251   set_method_handle_common(cpool, Bytecodes::_invokedynamic, call_info);
 252 }
 253 
 254 void ConstantPoolCacheEntry::set_method_handle_common(constantPoolHandle cpool,
 255                                                       Bytecodes::Code invoke_code,
 256                                                       const CallInfo &call_info) {
 257   // NOTE: This CPCE can be the subject of data races.
 258   // There are three words to update: flags, refs[f2], f1 (in that order).
 259   // Writers must store all other values before f1.
 260   // Readers must test f1 first for non-null before reading other fields.
 261   // Competing writers must acquire exclusive access via a lock.
 262   // A losing writer waits on the lock until the winner writes f1 and leaves
 263   // the lock, so that when the losing writer returns, he can use the linked
 264   // cache entry.
 265 
 266   MonitorLockerEx ml(cpool->lock());
 267   if (!is_f1_null()) {
 268     return;
 269   }
 270 
 271   const methodHandle adapter = call_info.resolved_method();
 272   const Handle appendix      = call_info.resolved_appendix();
 273   const Handle method_type   = call_info.resolved_method_type();
 274   const bool has_appendix    = appendix.not_null();
 275   const bool has_method_type = method_type.not_null();
 276 
 277   // Write the flags.
 278   set_method_flags(as_TosState(adapter->result_type()),
 279                    ((has_appendix    ? 1 : 0) << has_appendix_shift   ) |
 280                    ((has_method_type ? 1 : 0) << has_method_type_shift) |
 281                    (                   1      << is_final_shift       ),
 282                    adapter->size_of_parameters());
 283 
 284   if (TraceInvokeDynamic) {
 285     tty->print_cr("set_method_handle bc=%d appendix="PTR_FORMAT"%s method_type="PTR_FORMAT"%s method="PTR_FORMAT" ",
 286                   invoke_code,
 287                   (intptr_t)appendix(),    (has_appendix    ? "" : " (unused)"),
 288                   (intptr_t)method_type(), (has_method_type ? "" : " (unused)"),
 289                   (intptr_t)adapter());
 290     adapter->print();
 291     if (has_appendix)  appendix()->print();
 292   }
 293 
 294   // Method handle invokes and invokedynamic sites use both cp cache words.
 295   // refs[f2], if not null, contains a value passed as a trailing argument to the adapter.
 296   // In the general case, this could be the call site's MethodType,
 297   // for use with java.lang.Invokers.checkExactType, or else a CallSite object.
 298   // f1 contains the adapter method which manages the actual call.
 299   // In the general case, this is a compiled LambdaForm.
 300   // (The Java code is free to optimize these calls by binding other
 301   // sorts of methods and appendices to call sites.)
 302   // JVM-level linking is via f1, as if for invokespecial, and signatures are erased.
 303   // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.
 304   // Even with the appendix, the method will never take more than 255 parameter slots.
 305   //
 306   // This means that given a call site like (List)mh.invoke("foo"),
 307   // the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;',
 308   // not '(Ljava/lang/String;)Ljava/util/List;'.
 309   // The fact that String and List are involved is encoded in the MethodType in refs[f2].
 310   // This allows us to create fewer method oops, while keeping type safety.
 311   //
 312 
 313   objArrayHandle resolved_references = cpool->resolved_references();
 314   // Store appendix, if any.
 315   if (has_appendix) {
 316     const int appendix_index = f2_as_index() + _indy_resolved_references_appendix_offset;
 317     assert(appendix_index >= 0 && appendix_index < resolved_references->length(), "oob");
 318     assert(resolved_references->obj_at(appendix_index) == NULL, "init just once");
 319     resolved_references->obj_at_put(appendix_index, appendix());
 320   }
 321 
 322   // Store MethodType, if any.
 323   if (has_method_type) {
 324     const int method_type_index = f2_as_index() + _indy_resolved_references_method_type_offset;
 325     assert(method_type_index >= 0 && method_type_index < resolved_references->length(), "oob");
 326     assert(resolved_references->obj_at(method_type_index) == NULL, "init just once");
 327     resolved_references->obj_at_put(method_type_index, method_type());
 328   }
 329 
 330   release_set_f1(adapter());  // This must be the last one to set (see NOTE above)!
 331 
 332   // The interpreter assembly code does not check byte_2,
 333   // but it is used by is_resolved, method_if_resolved, etc.
 334   set_bytecode_1(invoke_code);
 335   NOT_PRODUCT(verify(tty));
 336   if (TraceInvokeDynamic) {
 337     this->print(tty, 0);
 338   }
 339 }
 340 
 341 Method* ConstantPoolCacheEntry::method_if_resolved(constantPoolHandle cpool) {
 342   // Decode the action of set_method and set_interface_call
 343   Bytecodes::Code invoke_code = bytecode_1();
 344   if (invoke_code != (Bytecodes::Code)0) {
 345     Metadata* f1 = (Metadata*)_f1;
 346     if (f1 != NULL) {
 347       switch (invoke_code) {
 348       case Bytecodes::_invokeinterface:
 349         assert(f1->is_klass(), "");
 350         return klassItable::method_for_itable_index((Klass*)f1, f2_as_index());
 351       case Bytecodes::_invokestatic:
 352       case Bytecodes::_invokespecial:
 353         assert(!has_appendix(), "");
 354       case Bytecodes::_invokehandle:
 355       case Bytecodes::_invokedynamic:
 356         assert(f1->is_method(), "");
 357         return (Method*)f1;
 358       }
 359     }
 360   }
 361   invoke_code = bytecode_2();
 362   if (invoke_code != (Bytecodes::Code)0) {
 363     switch (invoke_code) {
 364     case Bytecodes::_invokevirtual:
 365       if (is_vfinal()) {
 366         // invokevirtual
 367         Method* m = f2_as_vfinal_method();
 368         assert(m->is_method(), "");
 369         return m;
 370       } else {
 371         int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index());
 372         if (cpool->tag_at(holder_index).is_klass()) {
 373           Klass* klass = cpool->resolved_klass_at(holder_index);
 374           if (!klass->oop_is_instance())
 375             klass = SystemDictionary::Object_klass();
 376           return InstanceKlass::cast(klass)->method_at_vtable(f2_as_index());
 377         }
 378       }
 379       break;
 380     }
 381   }
 382   return NULL;
 383 }
 384 
 385 
 386 oop ConstantPoolCacheEntry::appendix_if_resolved(constantPoolHandle cpool) {
 387   if (is_f1_null() || !has_appendix())
 388     return NULL;
 389   const int ref_index = f2_as_index() + _indy_resolved_references_appendix_offset;
 390   objArrayOop resolved_references = cpool->resolved_references();
 391   return resolved_references->obj_at(ref_index);
 392 }
 393 
 394 
 395 oop ConstantPoolCacheEntry::method_type_if_resolved(constantPoolHandle cpool) {
 396   if (is_f1_null() || !has_method_type())
 397     return NULL;
 398   const int ref_index = f2_as_index() + _indy_resolved_references_method_type_offset;
 399   objArrayOop resolved_references = cpool->resolved_references();
 400   return resolved_references->obj_at(ref_index);
 401 }
 402 
 403 
 404 // RedefineClasses() API support:
 405 // If this ConstantPoolCacheEntry refers to old_method then update it
 406 // to refer to new_method.
 407 bool ConstantPoolCacheEntry::adjust_method_entry(Method* old_method,
 408        Method* new_method, bool * trace_name_printed) {
 409 
 410   if (is_vfinal()) {
 411     // virtual and final so _f2 contains method ptr instead of vtable index
 412     if (f2_as_vfinal_method() == old_method) {
 413       // match old_method so need an update
 414       // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values
 415       _f2 = (intptr_t)new_method;
 416       if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
 417         if (!(*trace_name_printed)) {
 418           // RC_TRACE_MESG macro has an embedded ResourceMark
 419           RC_TRACE_MESG(("adjust: name=%s",
 420             old_method->method_holder()->external_name()));
 421           *trace_name_printed = true;
 422         }
 423         // RC_TRACE macro has an embedded ResourceMark
 424         RC_TRACE(0x00400000, ("cpc vf-entry update: %s(%s)",
 425           new_method->name()->as_C_string(),
 426           new_method->signature()->as_C_string()));
 427       }
 428 
 429       return true;
 430     }
 431 
 432     // f1() is not used with virtual entries so bail out
 433     return false;
 434   }
 435 
 436   if (_f1 == NULL) {
 437     // NULL f1() means this is a virtual entry so bail out
 438     // We are assuming that the vtable index does not need change.
 439     return false;
 440   }
 441 
 442   if (_f1 == old_method) {
 443     _f1 = new_method;
 444     if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
 445       if (!(*trace_name_printed)) {
 446         // RC_TRACE_MESG macro has an embedded ResourceMark
 447         RC_TRACE_MESG(("adjust: name=%s",
 448           old_method->method_holder()->external_name()));
 449         *trace_name_printed = true;
 450       }
 451       // RC_TRACE macro has an embedded ResourceMark
 452       RC_TRACE(0x00400000, ("cpc entry update: %s(%s)",
 453         new_method->name()->as_C_string(),
 454         new_method->signature()->as_C_string()));
 455     }
 456 
 457     return true;
 458   }
 459 
 460   return false;
 461 }
 462 
 463 // a constant pool cache entry should never contain old or obsolete methods
 464 bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() {
 465   if (is_vfinal()) {
 466     // virtual and final so _f2 contains method ptr instead of vtable index
 467     Metadata* f2 = (Metadata*)_f2;
 468     // Return false if _f2 refers to an old or an obsolete method.
 469     // _f2 == NULL || !_f2->is_method() are just as unexpected here.
 470     return (f2 != NULL NOT_PRODUCT(&& f2->is_valid()) && f2->is_method() &&
 471             !((Method*)f2)->is_old() && !((Method*)f2)->is_obsolete());
 472   } else if (_f1 == NULL ||
 473              (NOT_PRODUCT(_f1->is_valid() &&) !_f1->is_method())) {
 474     // _f1 == NULL || !_f1->is_method() are OK here
 475     return true;
 476   }
 477   // return false if _f1 refers to an old or an obsolete method
 478   return (NOT_PRODUCT(_f1->is_valid() &&) _f1->is_method() &&
 479           !((Method*)_f1)->is_old() && !((Method*)_f1)->is_obsolete());
 480 }
 481 
 482 bool ConstantPoolCacheEntry::is_interesting_method_entry(Klass* k) {
 483   if (!is_method_entry()) {
 484     // not a method entry so not interesting by default
 485     return false;
 486   }
 487 
 488   Method* m = NULL;
 489   if (is_vfinal()) {
 490     // virtual and final so _f2 contains method ptr instead of vtable index
 491     m = f2_as_vfinal_method();
 492   } else if (is_f1_null()) {
 493     // NULL _f1 means this is a virtual entry so also not interesting
 494     return false;
 495   } else {
 496     if (!(_f1->is_method())) {
 497       // _f1 can also contain a Klass* for an interface
 498       return false;
 499     }
 500     m = f1_as_method();
 501   }
 502 
 503   assert(m != NULL && m->is_method(), "sanity check");
 504   if (m == NULL || !m->is_method() || (k != NULL && m->method_holder() != k)) {
 505     // robustness for above sanity checks or method is not in
 506     // the interesting class
 507     return false;
 508   }
 509 
 510   // the method is in the interesting class so the entry is interesting
 511   return true;
 512 }
 513 
 514 void ConstantPoolCacheEntry::print(outputStream* st, int index) const {
 515   // print separator
 516   if (index == 0) st->print_cr("                 -------------");
 517   // print entry
 518   st->print("%3d  ("PTR_FORMAT")  ", index, (intptr_t)this);
 519   st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(),
 520                constant_pool_index());
 521   st->print_cr("                 [   "PTR_FORMAT"]", (intptr_t)_f1);
 522   st->print_cr("                 [   "PTR_FORMAT"]", (intptr_t)_f2);
 523   st->print_cr("                 [   "PTR_FORMAT"]", (intptr_t)_flags);
 524   st->print_cr("                 -------------");
 525 }
 526 
 527 void ConstantPoolCacheEntry::verify(outputStream* st) const {
 528   // not implemented yet
 529 }
 530 
 531 // Implementation of ConstantPoolCache
 532 
 533 ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
 534   int size = ConstantPoolCache::size(length);
 535 
 536   return new (loader_data, size, false, THREAD) ConstantPoolCache(length);
 537 }
 538 
 539 void ConstantPoolCache::initialize(intArray& inverse_index_map, intArray& invokedynamic_references_map) {
 540   assert(inverse_index_map.length() == length(), "inverse index map must have same length as cache");
 541   for (int i = 0; i < length(); i++) {
 542     ConstantPoolCacheEntry* e = entry_at(i);
 543     int original_index = inverse_index_map[i];
 544     e->initialize_entry(original_index);
 545     assert(entry_at(i) == e, "sanity");
 546   }
 547   for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) {
 548     const int cpci = invokedynamic_references_map[ref];
 549     if (cpci >= 0) {
 550 #ifdef ASSERT
 551       // invokedynamic and invokehandle have more entries; check if they
 552       // all point to the same constant pool cache entry.
 553       for (int entry = 1; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) {
 554         const int cpci_next = invokedynamic_references_map[ref + entry];
 555         assert(cpci == cpci_next, err_msg_res("%d == %d", cpci, cpci_next));
 556       }
 557 #endif
 558       entry_at(cpci)->initialize_resolved_reference_index(ref);
 559       ref += ConstantPoolCacheEntry::_indy_resolved_references_entries - 1;  // skip extra entries
 560     }
 561   }
 562 }
 563 
 564 // RedefineClasses() API support:
 565 // If any entry of this ConstantPoolCache points to any of
 566 // old_methods, replace it with the corresponding new_method.
 567 void ConstantPoolCache::adjust_method_entries(Method** old_methods, Method** new_methods,
 568                                                      int methods_length, bool * trace_name_printed) {
 569 
 570   if (methods_length == 0) {
 571     // nothing to do if there are no methods
 572     return;
 573   }
 574 
 575   // get shorthand for the interesting class
 576   Klass* old_holder = old_methods[0]->method_holder();
 577 
 578   for (int i = 0; i < length(); i++) {
 579     if (!entry_at(i)->is_interesting_method_entry(old_holder)) {
 580       // skip uninteresting methods
 581       continue;
 582     }
 583 
 584     // The ConstantPoolCache contains entries for several different
 585     // things, but we only care about methods. In fact, we only care
 586     // about methods in the same class as the one that contains the
 587     // old_methods. At this point, we have an interesting entry.
 588 
 589     for (int j = 0; j < methods_length; j++) {
 590       Method* old_method = old_methods[j];
 591       Method* new_method = new_methods[j];
 592 
 593       if (entry_at(i)->adjust_method_entry(old_method, new_method,
 594           trace_name_printed)) {
 595         // current old_method matched this entry and we updated it so
 596         // break out and get to the next interesting entry if there one
 597         break;
 598       }
 599     }
 600   }
 601 }
 602 
 603 // the constant pool cache should never contain old or obsolete methods
 604 bool ConstantPoolCache::check_no_old_or_obsolete_entries() {
 605   for (int i = 1; i < length(); i++) {
 606     if (entry_at(i)->is_interesting_method_entry(NULL) &&
 607         !entry_at(i)->check_no_old_or_obsolete_entries()) {
 608       return false;
 609     }
 610   }
 611   return true;
 612 }
 613 
 614 void ConstantPoolCache::dump_cache() {
 615   for (int i = 1; i < length(); i++) {
 616     if (entry_at(i)->is_interesting_method_entry(NULL)) {
 617       entry_at(i)->print(tty, i);
 618     }
 619   }
 620 }
 621 
 622 
 623 // Printing
 624 
 625 void ConstantPoolCache::print_on(outputStream* st) const {
 626   assert(is_constantPoolCache(), "obj must be constant pool cache");
 627   st->print_cr(internal_name());
 628   // print constant pool cache entries
 629   for (int i = 0; i < length(); i++) entry_at(i)->print(st, i);
 630 }
 631 
 632 void ConstantPoolCache::print_value_on(outputStream* st) const {
 633   assert(is_constantPoolCache(), "obj must be constant pool cache");
 634   st->print("cache [%d]", length());
 635   print_address_on(st);
 636   st->print(" for ");
 637   constant_pool()->print_value_on(st);
 638 }
 639 
 640 
 641 // Verification
 642 
 643 void ConstantPoolCache::verify_on(outputStream* st) {
 644   guarantee(is_constantPoolCache(), "obj must be constant pool cache");
 645   // print constant pool cache entries
 646   for (int i = 0; i < length(); i++) entry_at(i)->verify(st);
 647 }