1 /*
   2  * Copyright (c) 1998, 2017, 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 "interpreter/interpreter.hpp"
  27 #include "interpreter/rewriter.hpp"
  28 #include "logging/log.hpp"
  29 #include "memory/resourceArea.hpp"
  30 #include "memory/universe.inline.hpp"
  31 #include "oops/cpCache.hpp"
  32 #include "oops/objArrayOop.inline.hpp"
  33 #include "oops/oop.inline.hpp"
  34 #include "prims/methodHandles.hpp"
  35 #include "runtime/atomic.hpp"
  36 #include "runtime/handles.inline.hpp"
  37 #include "runtime/orderAccess.inline.hpp"
  38 #include "utilities/macros.hpp"
  39 
  40 // Implementation of ConstantPoolCacheEntry
  41 
  42 void ConstantPoolCacheEntry::initialize_entry(int index) {
  43   assert(0 < index && index < 0x10000, "sanity check");
  44   _indices = index;
  45   _f1 = NULL;
  46   _f2 = _flags = 0;
  47   assert(constant_pool_index() == index, "");
  48 }
  49 
  50 int ConstantPoolCacheEntry::make_flags(TosState state,
  51                                        int option_bits,
  52                                        int field_index_or_method_params) {
  53   assert(state < number_of_states, "Invalid state in make_flags");
  54   int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params;
  55   // Preserve existing flag bit values
  56   // The low bits are a field offset, or else the method parameter size.
  57 #ifdef ASSERT
  58   TosState old_state = flag_state();
  59   assert(old_state == (TosState)0 || old_state == state,
  60          "inconsistent cpCache flags state");
  61 #endif
  62   return (_flags | f) ;
  63 }
  64 
  65 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) {
  66 #ifdef ASSERT
  67   // Read once.
  68   volatile Bytecodes::Code c = bytecode_1();
  69   assert(c == 0 || c == code || code == 0, "update must be consistent");
  70 #endif
  71   // Need to flush pending stores here before bytecode is written.
  72   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_1_shift));
  73 }
  74 
  75 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {
  76 #ifdef ASSERT
  77   // Read once.
  78   volatile Bytecodes::Code c = bytecode_2();
  79   assert(c == 0 || c == code || code == 0, "update must be consistent");
  80 #endif
  81   // Need to flush pending stores here before bytecode is written.
  82   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_2_shift));
  83 }
  84 
  85 // Sets f1, ordering with previous writes.
  86 void ConstantPoolCacheEntry::release_set_f1(Metadata* f1) {
  87   assert(f1 != NULL, "");
  88   OrderAccess::release_store_ptr((HeapWord*) &_f1, f1);
  89 }
  90 
  91 // Sets flags, but only if the value was previously zero.
  92 bool ConstantPoolCacheEntry::init_flags_atomic(intptr_t flags) {
  93   intptr_t result = Atomic::cmpxchg_ptr(flags, &_flags, 0);
  94   return (result == 0);
  95 }
  96 
  97 // Note that concurrent update of both bytecodes can leave one of them
  98 // reset to zero.  This is harmless; the interpreter will simply re-resolve
  99 // the damaged entry.  More seriously, the memory synchronization is needed
 100 // to flush other fields (f1, f2) completely to memory before the bytecodes
 101 // are updated, lest other processors see a non-zero bytecode but zero f1/f2.
 102 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code,
 103                                        Bytecodes::Code put_code,
 104                                        Klass* field_holder,
 105                                        int field_index,
 106                                        int field_offset,
 107                                        TosState field_type,
 108                                        bool is_final,
 109                                        bool is_volatile,
 110                                        Klass* root_klass) {
 111   set_f1(field_holder);
 112   set_f2(field_offset);
 113   assert((field_index & field_index_mask) == field_index,
 114          "field index does not fit in low flag bits");
 115   set_field_flags(field_type,
 116                   ((is_volatile ? 1 : 0) << is_volatile_shift) |
 117                   ((is_final    ? 1 : 0) << is_final_shift),
 118                   field_index);
 119   set_bytecode_1(get_code);
 120   set_bytecode_2(put_code);
 121   NOT_PRODUCT(verify(tty));
 122 }
 123 
 124 void ConstantPoolCacheEntry::set_parameter_size(int value) {
 125   // This routine is called only in corner cases where the CPCE is not yet initialized.
 126   // See AbstractInterpreter::deopt_continue_after_entry.
 127   assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value,
 128          "size must not change: parameter_size=%d, value=%d", parameter_size(), value);
 129   // Setting the parameter size by itself is only safe if the
 130   // current value of _flags is 0, otherwise another thread may have
 131   // updated it and we don't want to overwrite that value.  Don't
 132   // bother trying to update it once it's nonzero but always make
 133   // sure that the final parameter size agrees with what was passed.
 134   if (_flags == 0) {
 135     Atomic::cmpxchg_ptr((value & parameter_size_mask), &_flags, 0);
 136   }
 137   guarantee(parameter_size() == value,
 138             "size must not change: parameter_size=%d, value=%d", parameter_size(), value);
 139 }
 140 
 141 void ConstantPoolCacheEntry::set_direct_or_vtable_call(Bytecodes::Code invoke_code,
 142                                                        methodHandle method,
 143                                                        int vtable_index,
 144                                                        bool sender_is_interface) {
 145   bool is_vtable_call = (vtable_index >= 0);  // FIXME: split this method on this boolean
 146   assert(method->interpreter_entry() != NULL, "should have been set at this point");
 147   assert(!method->is_obsolete(),  "attempt to write obsolete method to cpCache");
 148 
 149   int byte_no = -1;
 150   bool change_to_virtual = false;
 151 
 152   switch (invoke_code) {
 153     case Bytecodes::_invokeinterface:
 154       // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface
 155       // instruction somehow links to a non-interface method (in Object).
 156       // In that case, the method has no itable index and must be invoked as a virtual.
 157       // Set a flag to keep track of this corner case.
 158       change_to_virtual = true;
 159 
 160       // ...and fall through as if we were handling invokevirtual:
 161     case Bytecodes::_invokevirtual:
 162       {
 163         if (!is_vtable_call) {
 164           assert(method->can_be_statically_bound(), "");
 165           // set_f2_as_vfinal_method checks if is_vfinal flag is true.
 166           set_method_flags(as_TosState(method->result_type()),
 167                            (                             1      << is_vfinal_shift) |
 168                            ((method->is_final_method() ? 1 : 0) << is_final_shift)  |
 169                            ((change_to_virtual         ? 1 : 0) << is_forced_virtual_shift),
 170                            method()->size_of_parameters());
 171           set_f2_as_vfinal_method(method());
 172         } else {
 173           assert(!method->can_be_statically_bound(), "");
 174           assert(vtable_index >= 0, "valid index");
 175           assert(!method->is_final_method(), "sanity");
 176           set_method_flags(as_TosState(method->result_type()),
 177                            ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
 178                            method()->size_of_parameters());
 179           set_f2(vtable_index);
 180         }
 181         byte_no = 2;
 182         break;
 183       }
 184 
 185     case Bytecodes::_invokespecial:
 186     case Bytecodes::_invokestatic:
 187       assert(!is_vtable_call, "");
 188       // Note:  Read and preserve the value of the is_vfinal flag on any
 189       // invokevirtual bytecode shared with this constant pool cache entry.
 190       // It is cheap and safe to consult is_vfinal() at all times.
 191       // Once is_vfinal is set, it must stay that way, lest we get a dangling oop.
 192       set_method_flags(as_TosState(method->result_type()),
 193                        ((is_vfinal()               ? 1 : 0) << is_vfinal_shift) |
 194                        ((method->is_final_method() ? 1 : 0) << is_final_shift),
 195                        method()->size_of_parameters());
 196       set_f1(method());
 197       byte_no = 1;
 198       break;
 199     default:
 200       ShouldNotReachHere();
 201       break;
 202   }
 203 
 204   // Note:  byte_no also appears in TemplateTable::resolve.
 205   if (byte_no == 1) {
 206     assert(invoke_code != Bytecodes::_invokevirtual &&
 207            invoke_code != Bytecodes::_invokeinterface, "");
 208     // Don't mark invokespecial to method as resolved if sender is an interface.  The receiver
 209     // has to be checked that it is a subclass of the current class every time this bytecode
 210     // is executed.
 211     if (invoke_code != Bytecodes::_invokespecial || !sender_is_interface ||
 212         method->name() == vmSymbols::object_initializer_name()) {
 213     set_bytecode_1(invoke_code);
 214     }
 215   } else if (byte_no == 2)  {
 216     if (change_to_virtual) {
 217       assert(invoke_code == Bytecodes::_invokeinterface, "");
 218       // NOTE: THIS IS A HACK - BE VERY CAREFUL!!!
 219       //
 220       // Workaround for the case where we encounter an invokeinterface, but we
 221       // should really have an _invokevirtual since the resolved method is a
 222       // virtual method in java.lang.Object. This is a corner case in the spec
 223       // but is presumably legal. javac does not generate this code.
 224       //
 225       // We set bytecode_1() to _invokeinterface, because that is the
 226       // bytecode # used by the interpreter to see if it is resolved.
 227       // We set bytecode_2() to _invokevirtual.
 228       // See also interpreterRuntime.cpp. (8/25/2000)
 229       // Only set resolved for the invokeinterface case if method is public.
 230       // Otherwise, the method needs to be reresolved with caller for each
 231       // interface call.
 232       if (method->is_public()) set_bytecode_1(invoke_code);
 233     } else {
 234       assert(invoke_code == Bytecodes::_invokevirtual, "");
 235     }
 236     // set up for invokevirtual, even if linking for invokeinterface also:
 237     set_bytecode_2(Bytecodes::_invokevirtual);
 238   } else {
 239     ShouldNotReachHere();
 240   }
 241   NOT_PRODUCT(verify(tty));
 242 }
 243 
 244 void ConstantPoolCacheEntry::set_direct_call(Bytecodes::Code invoke_code, methodHandle method,
 245                                              bool sender_is_interface) {
 246   int index = Method::nonvirtual_vtable_index;
 247   // index < 0; FIXME: inline and customize set_direct_or_vtable_call
 248   set_direct_or_vtable_call(invoke_code, method, index, sender_is_interface);
 249 }
 250 
 251 void ConstantPoolCacheEntry::set_vtable_call(Bytecodes::Code invoke_code, methodHandle method, int index) {
 252   // either the method is a miranda or its holder should accept the given index
 253   assert(method->method_holder()->is_interface() || method->method_holder()->verify_vtable_index(index), "");
 254   // index >= 0; FIXME: inline and customize set_direct_or_vtable_call
 255   set_direct_or_vtable_call(invoke_code, method, index, false);
 256 }
 257 
 258 void ConstantPoolCacheEntry::set_itable_call(Bytecodes::Code invoke_code, const methodHandle& method, int index) {
 259   assert(method->method_holder()->verify_itable_index(index), "");
 260   assert(invoke_code == Bytecodes::_invokeinterface, "");
 261   InstanceKlass* interf = method->method_holder();
 262   assert(interf->is_interface(), "must be an interface");
 263   assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");
 264   set_f1(interf);
 265   set_f2(index);
 266   set_method_flags(as_TosState(method->result_type()),
 267                    0,  // no option bits
 268                    method()->size_of_parameters());
 269   set_bytecode_1(Bytecodes::_invokeinterface);
 270 }
 271 
 272 
 273 void ConstantPoolCacheEntry::set_method_handle(const constantPoolHandle& cpool, const CallInfo &call_info) {
 274   set_method_handle_common(cpool, Bytecodes::_invokehandle, call_info);
 275 }
 276 
 277 void ConstantPoolCacheEntry::set_dynamic_call(const constantPoolHandle& cpool, const CallInfo &call_info) {
 278   set_method_handle_common(cpool, Bytecodes::_invokedynamic, call_info);
 279 }
 280 
 281 void ConstantPoolCacheEntry::set_method_handle_common(const constantPoolHandle& cpool,
 282                                                       Bytecodes::Code invoke_code,
 283                                                       const CallInfo &call_info) {
 284   // NOTE: This CPCE can be the subject of data races.
 285   // There are three words to update: flags, refs[f2], f1 (in that order).
 286   // Writers must store all other values before f1.
 287   // Readers must test f1 first for non-null before reading other fields.
 288   // Competing writers must acquire exclusive access via a lock.
 289   // A losing writer waits on the lock until the winner writes f1 and leaves
 290   // the lock, so that when the losing writer returns, he can use the linked
 291   // cache entry.
 292 
 293   objArrayHandle resolved_references(Thread::current(), cpool->resolved_references());
 294   // Use the resolved_references() lock for this cpCache entry.
 295   // resolved_references are created for all classes with Invokedynamic, MethodHandle
 296   // or MethodType constant pool cache entries.
 297   assert(resolved_references() != NULL,
 298          "a resolved_references array should have been created for this class");
 299   ObjectLocker ol(resolved_references, Thread::current());
 300   if (!is_f1_null()) {
 301     return;
 302   }
 303 
 304   const methodHandle adapter = call_info.resolved_method();
 305   const Handle appendix      = call_info.resolved_appendix();
 306   const Handle method_type   = call_info.resolved_method_type();
 307   const bool has_appendix    = appendix.not_null();
 308   const bool has_method_type = method_type.not_null();
 309 
 310   // Write the flags.
 311   set_method_flags(as_TosState(adapter->result_type()),
 312                    ((has_appendix    ? 1 : 0) << has_appendix_shift   ) |
 313                    ((has_method_type ? 1 : 0) << has_method_type_shift) |
 314                    (                   1      << is_final_shift       ),
 315                    adapter->size_of_parameters());
 316 
 317   if (TraceInvokeDynamic) {
 318     ttyLocker ttyl;
 319     tty->print_cr("set_method_handle bc=%d appendix=" PTR_FORMAT "%s method_type=" PTR_FORMAT "%s method=" PTR_FORMAT " ",
 320                   invoke_code,
 321                   p2i(appendix()),    (has_appendix    ? "" : " (unused)"),
 322                   p2i(method_type()), (has_method_type ? "" : " (unused)"),
 323                   p2i(adapter()));
 324     adapter->print();
 325     if (has_appendix)  appendix()->print();
 326   }
 327 
 328   // Method handle invokes and invokedynamic sites use both cp cache words.
 329   // refs[f2], if not null, contains a value passed as a trailing argument to the adapter.
 330   // In the general case, this could be the call site's MethodType,
 331   // for use with java.lang.Invokers.checkExactType, or else a CallSite object.
 332   // f1 contains the adapter method which manages the actual call.
 333   // In the general case, this is a compiled LambdaForm.
 334   // (The Java code is free to optimize these calls by binding other
 335   // sorts of methods and appendices to call sites.)
 336   // JVM-level linking is via f1, as if for invokespecial, and signatures are erased.
 337   // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.
 338   // Even with the appendix, the method will never take more than 255 parameter slots.
 339   //
 340   // This means that given a call site like (List)mh.invoke("foo"),
 341   // the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;',
 342   // not '(Ljava/lang/String;)Ljava/util/List;'.
 343   // The fact that String and List are involved is encoded in the MethodType in refs[f2].
 344   // This allows us to create fewer Methods, while keeping type safety.
 345   //
 346 
 347   // Store appendix, if any.
 348   if (has_appendix) {
 349     const int appendix_index = f2_as_index() + _indy_resolved_references_appendix_offset;
 350     assert(appendix_index >= 0 && appendix_index < resolved_references->length(), "oob");
 351     assert(resolved_references->obj_at(appendix_index) == NULL, "init just once");
 352     resolved_references->obj_at_put(appendix_index, appendix());
 353   }
 354 
 355   // Store MethodType, if any.
 356   if (has_method_type) {
 357     const int method_type_index = f2_as_index() + _indy_resolved_references_method_type_offset;
 358     assert(method_type_index >= 0 && method_type_index < resolved_references->length(), "oob");
 359     assert(resolved_references->obj_at(method_type_index) == NULL, "init just once");
 360     resolved_references->obj_at_put(method_type_index, method_type());
 361   }
 362 
 363   release_set_f1(adapter());  // This must be the last one to set (see NOTE above)!
 364 
 365   // The interpreter assembly code does not check byte_2,
 366   // but it is used by is_resolved, method_if_resolved, etc.
 367   set_bytecode_1(invoke_code);
 368   NOT_PRODUCT(verify(tty));
 369   if (TraceInvokeDynamic) {
 370     ttyLocker ttyl;
 371     this->print(tty, 0);
 372   }
 373 }
 374 
 375 Method* ConstantPoolCacheEntry::method_if_resolved(const constantPoolHandle& cpool) {
 376   // Decode the action of set_method and set_interface_call
 377   Bytecodes::Code invoke_code = bytecode_1();
 378   if (invoke_code != (Bytecodes::Code)0) {
 379     Metadata* f1 = f1_ord();
 380     if (f1 != NULL) {
 381       switch (invoke_code) {
 382       case Bytecodes::_invokeinterface:
 383         assert(f1->is_klass(), "");
 384         return klassItable::method_for_itable_index((Klass*)f1, f2_as_index());
 385       case Bytecodes::_invokestatic:
 386       case Bytecodes::_invokespecial:
 387         assert(!has_appendix(), "");
 388       case Bytecodes::_invokehandle:
 389       case Bytecodes::_invokedynamic:
 390         assert(f1->is_method(), "");
 391         return (Method*)f1;
 392       default:
 393         break;
 394       }
 395     }
 396   }
 397   invoke_code = bytecode_2();
 398   if (invoke_code != (Bytecodes::Code)0) {
 399     switch (invoke_code) {
 400     case Bytecodes::_invokevirtual:
 401       if (is_vfinal()) {
 402         // invokevirtual
 403         Method* m = f2_as_vfinal_method();
 404         assert(m->is_method(), "");
 405         return m;
 406       } else {
 407         int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index());
 408         if (cpool->tag_at(holder_index).is_klass()) {
 409           Klass* klass = cpool->resolved_klass_at(holder_index);
 410           return klass->method_at_vtable(f2_as_index());
 411         }
 412       }
 413       break;
 414     default:
 415       break;
 416     }
 417   }
 418   return NULL;
 419 }
 420 
 421 
 422 oop ConstantPoolCacheEntry::appendix_if_resolved(const constantPoolHandle& cpool) {
 423   if (!has_appendix())
 424     return NULL;
 425   const int ref_index = f2_as_index() + _indy_resolved_references_appendix_offset;
 426   objArrayOop resolved_references = cpool->resolved_references();
 427   return resolved_references->obj_at(ref_index);
 428 }
 429 
 430 
 431 oop ConstantPoolCacheEntry::method_type_if_resolved(const constantPoolHandle& cpool) {
 432   if (!has_method_type())
 433     return NULL;
 434   const int ref_index = f2_as_index() + _indy_resolved_references_method_type_offset;
 435   objArrayOop resolved_references = cpool->resolved_references();
 436   return resolved_references->obj_at(ref_index);
 437 }
 438 
 439 
 440 #if INCLUDE_JVMTI
 441 // RedefineClasses() API support:
 442 // If this ConstantPoolCacheEntry refers to old_method then update it
 443 // to refer to new_method.
 444 bool ConstantPoolCacheEntry::adjust_method_entry(Method* old_method,
 445        Method* new_method, bool * trace_name_printed) {
 446 
 447   if (is_vfinal()) {
 448     // virtual and final so _f2 contains method ptr instead of vtable index
 449     if (f2_as_vfinal_method() == old_method) {
 450       // match old_method so need an update
 451       // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values
 452       _f2 = (intptr_t)new_method;
 453       if (log_is_enabled(Info, redefine, class, update)) {
 454         ResourceMark rm;
 455         if (!(*trace_name_printed)) {
 456           log_info(redefine, class, update)("adjust: name=%s", old_method->method_holder()->external_name());
 457           *trace_name_printed = true;
 458         }
 459         log_debug(redefine, class, update, constantpool)
 460           ("cpc vf-entry update: %s(%s)", new_method->name()->as_C_string(), new_method->signature()->as_C_string());
 461       }
 462       return true;
 463     }
 464 
 465     // f1() is not used with virtual entries so bail out
 466     return false;
 467   }
 468 
 469   if (_f1 == NULL) {
 470     // NULL f1() means this is a virtual entry so bail out
 471     // We are assuming that the vtable index does not need change.
 472     return false;
 473   }
 474 
 475   if (_f1 == old_method) {
 476     _f1 = new_method;
 477     if (log_is_enabled(Info, redefine, class, update)) {
 478       ResourceMark rm;
 479       if (!(*trace_name_printed)) {
 480         log_info(redefine, class, update)("adjust: name=%s", old_method->method_holder()->external_name());
 481         *trace_name_printed = true;
 482       }
 483       log_debug(redefine, class, update, constantpool)
 484         ("cpc entry update: %s(%s)", new_method->name()->as_C_string(), new_method->signature()->as_C_string());
 485     }
 486     return true;
 487   }
 488 
 489   return false;
 490 }
 491 
 492 // a constant pool cache entry should never contain old or obsolete methods
 493 bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() {
 494   if (is_vfinal()) {
 495     // virtual and final so _f2 contains method ptr instead of vtable index
 496     Metadata* f2 = (Metadata*)_f2;
 497     // Return false if _f2 refers to an old or an obsolete method.
 498     // _f2 == NULL || !_f2->is_method() are just as unexpected here.
 499     return (f2 != NULL NOT_PRODUCT(&& f2->is_valid()) && f2->is_method() &&
 500             !((Method*)f2)->is_old() && !((Method*)f2)->is_obsolete());
 501   } else if (_f1 == NULL ||
 502              (NOT_PRODUCT(_f1->is_valid() &&) !_f1->is_method())) {
 503     // _f1 == NULL || !_f1->is_method() are OK here
 504     return true;
 505   }
 506   // return false if _f1 refers to a non-deleted old or obsolete method
 507   return (NOT_PRODUCT(_f1->is_valid() &&) _f1->is_method() &&
 508           (f1_as_method()->is_deleted() ||
 509           (!f1_as_method()->is_old() && !f1_as_method()->is_obsolete())));
 510 }
 511 
 512 Method* ConstantPoolCacheEntry::get_interesting_method_entry(Klass* k) {
 513   if (!is_method_entry()) {
 514     // not a method entry so not interesting by default
 515     return NULL;
 516   }
 517   Method* m = NULL;
 518   if (is_vfinal()) {
 519     // virtual and final so _f2 contains method ptr instead of vtable index
 520     m = f2_as_vfinal_method();
 521   } else if (is_f1_null()) {
 522     // NULL _f1 means this is a virtual entry so also not interesting
 523     return NULL;
 524   } else {
 525     if (!(_f1->is_method())) {
 526       // _f1 can also contain a Klass* for an interface
 527       return NULL;
 528     }
 529     m = f1_as_method();
 530   }
 531   assert(m != NULL && m->is_method(), "sanity check");
 532   if (m == NULL || !m->is_method() || (k != NULL && m->method_holder() != k)) {
 533     // robustness for above sanity checks or method is not in
 534     // the interesting class
 535     return NULL;
 536   }
 537   // the method is in the interesting class so the entry is interesting
 538   return m;
 539 }
 540 #endif // INCLUDE_JVMTI
 541 
 542 void ConstantPoolCacheEntry::print(outputStream* st, int index) const {
 543   // print separator
 544   if (index == 0) st->print_cr("                 -------------");
 545   // print entry
 546   st->print("%3d  (" PTR_FORMAT ")  ", index, (intptr_t)this);
 547   st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(),
 548                constant_pool_index());
 549   st->print_cr("                 [   " PTR_FORMAT "]", (intptr_t)_f1);
 550   st->print_cr("                 [   " PTR_FORMAT "]", (intptr_t)_f2);
 551   st->print_cr("                 [   " PTR_FORMAT "]", (intptr_t)_flags);
 552   st->print_cr("                 -------------");
 553 }
 554 
 555 void ConstantPoolCacheEntry::verify(outputStream* st) const {
 556   // not implemented yet
 557 }
 558 
 559 // Implementation of ConstantPoolCache
 560 
 561 ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data,
 562                                      const intStack& index_map,
 563                                      const intStack& invokedynamic_index_map,
 564                                      const intStack& invokedynamic_map, TRAPS) {
 565 
 566   const int length = index_map.length() + invokedynamic_index_map.length();
 567   int size = ConstantPoolCache::size(length);
 568 
 569   return new (loader_data, size, false, MetaspaceObj::ConstantPoolCacheType, THREAD)
 570     ConstantPoolCache(length, index_map, invokedynamic_index_map, invokedynamic_map);
 571 }
 572 
 573 void ConstantPoolCache::initialize(const intArray& inverse_index_map,
 574                                    const intArray& invokedynamic_inverse_index_map,
 575                                    const intArray& invokedynamic_references_map) {
 576   for (int i = 0; i < inverse_index_map.length(); i++) {
 577     ConstantPoolCacheEntry* e = entry_at(i);
 578     int original_index = inverse_index_map.at(i);
 579     e->initialize_entry(original_index);
 580     assert(entry_at(i) == e, "sanity");
 581   }
 582 
 583   // Append invokedynamic entries at the end
 584   int invokedynamic_offset = inverse_index_map.length();
 585   for (int i = 0; i < invokedynamic_inverse_index_map.length(); i++) {
 586     int offset = i + invokedynamic_offset;
 587     ConstantPoolCacheEntry* e = entry_at(offset);
 588     int original_index = invokedynamic_inverse_index_map.at(i);
 589     e->initialize_entry(original_index);
 590     assert(entry_at(offset) == e, "sanity");
 591   }
 592 
 593   for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) {
 594     const int cpci = invokedynamic_references_map.at(ref);
 595     if (cpci >= 0) {
 596 #ifdef ASSERT
 597       // invokedynamic and invokehandle have more entries; check if they
 598       // all point to the same constant pool cache entry.
 599       for (int entry = 1; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) {
 600         const int cpci_next = invokedynamic_references_map.at(ref + entry);
 601         assert(cpci == cpci_next, "%d == %d", cpci, cpci_next);
 602       }
 603 #endif
 604       entry_at(cpci)->initialize_resolved_reference_index(ref);
 605       ref += ConstantPoolCacheEntry::_indy_resolved_references_entries - 1;  // skip extra entries
 606     }
 607   }
 608 }
 609 
 610 #if INCLUDE_JVMTI
 611 // RedefineClasses() API support:
 612 // If any entry of this ConstantPoolCache points to any of
 613 // old_methods, replace it with the corresponding new_method.
 614 void ConstantPoolCache::adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed) {
 615   for (int i = 0; i < length(); i++) {
 616     ConstantPoolCacheEntry* entry = entry_at(i);
 617     Method* old_method = entry->get_interesting_method_entry(holder);
 618     if (old_method == NULL || !old_method->is_old()) {
 619       continue; // skip uninteresting entries
 620     }
 621     if (old_method->is_deleted()) {
 622       // clean up entries with deleted methods
 623       entry->initialize_entry(entry->constant_pool_index());
 624       continue;
 625     }
 626     Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
 627 
 628     assert(new_method != NULL, "method_with_idnum() should not be NULL");
 629     assert(old_method != new_method, "sanity check");
 630 
 631     entry_at(i)->adjust_method_entry(old_method, new_method, trace_name_printed);
 632   }
 633 }
 634 
 635 // the constant pool cache should never contain old or obsolete methods
 636 bool ConstantPoolCache::check_no_old_or_obsolete_entries() {
 637   for (int i = 1; i < length(); i++) {
 638     if (entry_at(i)->get_interesting_method_entry(NULL) != NULL &&
 639         !entry_at(i)->check_no_old_or_obsolete_entries()) {
 640       return false;
 641     }
 642   }
 643   return true;
 644 }
 645 
 646 void ConstantPoolCache::dump_cache() {
 647   for (int i = 1; i < length(); i++) {
 648     if (entry_at(i)->get_interesting_method_entry(NULL) != NULL) {
 649       entry_at(i)->print(tty, i);
 650     }
 651   }
 652 }
 653 #endif // INCLUDE_JVMTI
 654 
 655 
 656 // Printing
 657 
 658 void ConstantPoolCache::print_on(outputStream* st) const {
 659   assert(is_constantPoolCache(), "obj must be constant pool cache");
 660   st->print_cr("%s", internal_name());
 661   // print constant pool cache entries
 662   for (int i = 0; i < length(); i++) entry_at(i)->print(st, i);
 663 }
 664 
 665 void ConstantPoolCache::print_value_on(outputStream* st) const {
 666   assert(is_constantPoolCache(), "obj must be constant pool cache");
 667   st->print("cache [%d]", length());
 668   print_address_on(st);
 669   st->print(" for ");
 670   constant_pool()->print_value_on(st);
 671 }
 672 
 673 
 674 // Verification
 675 
 676 void ConstantPoolCache::verify_on(outputStream* st) {
 677   guarantee(is_constantPoolCache(), "obj must be constant pool cache");
 678   // print constant pool cache entries
 679   for (int i = 0; i < length(); i++) entry_at(i)->verify(st);
 680 }
--- EOF ---