1 /*
   2  * Copyright (c) 1998, 2014, 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 #include "runtime/orderAccess.inline.hpp"
  37 #include "utilities/macros.hpp"
  38 #if INCLUDE_ALL_GCS
  39 # include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
  40 #endif // INCLUDE_ALL_GCS
  41 
  42 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  43 
  44 // Implementation of ConstantPoolCacheEntry
  45 
  46 void ConstantPoolCacheEntry::initialize_entry(int index) {
  47   assert(0 < index && index < 0x10000, "sanity check");
  48   _indices = index;
  49   _f1 = NULL;
  50   _f2 = _flags = 0;
  51   assert(constant_pool_index() == index, "");
  52 }
  53 
  54 int ConstantPoolCacheEntry::make_flags(TosState state,
  55                                        int option_bits,
  56                                        int field_index_or_method_params) {
  57   assert(state < number_of_states, "Invalid state in make_flags");
  58   int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params;
  59   // Preserve existing flag bit values
  60   // The low bits are a field offset, or else the method parameter size.
  61 #ifdef ASSERT
  62   TosState old_state = flag_state();
  63   assert(old_state == (TosState)0 || old_state == state,
  64          "inconsistent cpCache flags state");
  65 #endif
  66   return (_flags | f) ;
  67 }
  68 
  69 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) {
  70 #ifdef ASSERT
  71   // Read once.
  72   volatile Bytecodes::Code c = bytecode_1();
  73   assert(c == 0 || c == code || code == 0, "update must be consistent");
  74 #endif
  75   // Need to flush pending stores here before bytecode is written.
  76   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_1_shift));
  77 }
  78 
  79 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {
  80 #ifdef ASSERT
  81   // Read once.
  82   volatile Bytecodes::Code c = bytecode_2();
  83   assert(c == 0 || c == code || code == 0, "update must be consistent");
  84 #endif
  85   // Need to flush pending stores here before bytecode is written.
  86   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_2_shift));
  87 }
  88 
  89 // Sets f1, ordering with previous writes.
  90 void ConstantPoolCacheEntry::release_set_f1(Metadata* f1) {
  91   assert(f1 != NULL, "");
  92   OrderAccess::release_store_ptr((HeapWord*) &_f1, f1);
  93 }
  94 
  95 // Sets flags, but only if the value was previously zero.
  96 bool ConstantPoolCacheEntry::init_flags_atomic(intptr_t flags) {
  97   intptr_t result = Atomic::cmpxchg_ptr(flags, &_flags, 0);
  98   return (result == 0);
  99 }
 100 
 101 // Note that concurrent update of both bytecodes can leave one of them
 102 // reset to zero.  This is harmless; the interpreter will simply re-resolve
 103 // the damaged entry.  More seriously, the memory synchronization is needed
 104 // to flush other fields (f1, f2) completely to memory before the bytecodes
 105 // are updated, lest other processors see a non-zero bytecode but zero f1/f2.
 106 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code,
 107                                        Bytecodes::Code put_code,
 108                                        KlassHandle field_holder,
 109                                        int field_index,
 110                                        int field_offset,
 111                                        TosState field_type,
 112                                        bool is_final,
 113                                        bool is_volatile,
 114                                        Klass* root_klass) {
 115   set_f1(field_holder());
 116   set_f2(field_offset);
 117   assert((field_index & field_index_mask) == field_index,
 118          "field index does not fit in low flag bits");
 119   set_field_flags(field_type,
 120                   ((is_volatile ? 1 : 0) << is_volatile_shift) |
 121                   ((is_final    ? 1 : 0) << is_final_shift),
 122                   field_index);
 123   set_bytecode_1(get_code);
 124   set_bytecode_2(put_code);
 125   NOT_PRODUCT(verify(tty));
 126 }
 127 
 128 void ConstantPoolCacheEntry::set_parameter_size(int value) {
 129   // This routine is called only in corner cases where the CPCE is not yet initialized.
 130   // See AbstractInterpreter::deopt_continue_after_entry.
 131   assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value,
 132          err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value));
 133   // Setting the parameter size by itself is only safe if the
 134   // current value of _flags is 0, otherwise another thread may have
 135   // updated it and we don't want to overwrite that value.  Don't
 136   // bother trying to update it once it's nonzero but always make
 137   // sure that the final parameter size agrees with what was passed.
 138   if (_flags == 0) {
 139     Atomic::cmpxchg_ptr((value & parameter_size_mask), &_flags, 0);
 140   }
 141   guarantee(parameter_size() == value,
 142             err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value));
 143 }
 144 
 145 void ConstantPoolCacheEntry::set_direct_or_vtable_call(Bytecodes::Code invoke_code,
 146                                                        methodHandle method,
 147                                                        int vtable_index) {
 148   bool is_vtable_call = (vtable_index >= 0);  // FIXME: split this method on this boolean
 149   assert(method->interpreter_entry() != NULL, "should have been set at this point");
 150   assert(!method->is_obsolete(),  "attempt to write obsolete method to cpCache");
 151 
 152   int byte_no = -1;
 153   bool change_to_virtual = false;
 154 
 155   switch (invoke_code) {
 156     case Bytecodes::_invokeinterface:
 157       // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface
 158       // instruction somehow links to a non-interface method (in Object).
 159       // In that case, the method has no itable index and must be invoked as a virtual.
 160       // Set a flag to keep track of this corner case.
 161       change_to_virtual = true;
 162 
 163       // ...and fall through as if we were handling invokevirtual:
 164     case Bytecodes::_invokevirtual:
 165       {
 166         if (!is_vtable_call) {
 167           assert(method->can_be_statically_bound(), "");
 168           // set_f2_as_vfinal_method checks if is_vfinal flag is true.
 169           set_method_flags(as_TosState(method->result_type()),
 170                            (                             1      << is_vfinal_shift) |
 171                            ((method->is_final_method() ? 1 : 0) << is_final_shift)  |
 172                            ((change_to_virtual         ? 1 : 0) << is_forced_virtual_shift),
 173                            method()->size_of_parameters());
 174           set_f2_as_vfinal_method(method());
 175         } else {
 176           assert(!method->can_be_statically_bound(), "");
 177           assert(vtable_index >= 0, "valid index");
 178           assert(!method->is_final_method(), "sanity");
 179           set_method_flags(as_TosState(method->result_type()),
 180                            ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
 181                            method()->size_of_parameters());
 182           set_f2(vtable_index);
 183         }
 184         byte_no = 2;
 185         break;
 186       }
 187 
 188     case Bytecodes::_invokespecial:
 189     case Bytecodes::_invokestatic:
 190       assert(!is_vtable_call, "");
 191       // Note:  Read and preserve the value of the is_vfinal flag on any
 192       // invokevirtual bytecode shared with this constant pool cache entry.
 193       // It is cheap and safe to consult is_vfinal() at all times.
 194       // Once is_vfinal is set, it must stay that way, lest we get a dangling oop.
 195       set_method_flags(as_TosState(method->result_type()),
 196                        ((is_vfinal()               ? 1 : 0) << is_vfinal_shift) |
 197                        ((method->is_final_method() ? 1 : 0) << is_final_shift),
 198                        method()->size_of_parameters());
 199       set_f1(method());
 200       byte_no = 1;
 201       break;
 202     default:
 203       ShouldNotReachHere();
 204       break;
 205   }
 206 
 207   // Note:  byte_no also appears in TemplateTable::resolve.
 208   if (byte_no == 1) {
 209     assert(invoke_code != Bytecodes::_invokevirtual &&
 210            invoke_code != Bytecodes::_invokeinterface, "");
 211     set_bytecode_1(invoke_code);
 212   } else if (byte_no == 2)  {
 213     if (change_to_virtual) {
 214       assert(invoke_code == Bytecodes::_invokeinterface, "");
 215       // NOTE: THIS IS A HACK - BE VERY CAREFUL!!!
 216       //
 217       // Workaround for the case where we encounter an invokeinterface, but we
 218       // should really have an _invokevirtual since the resolved method is a
 219       // virtual method in java.lang.Object. This is a corner case in the spec
 220       // but is presumably legal. javac does not generate this code.
 221       //
 222       // We set bytecode_1() to _invokeinterface, because that is the
 223       // bytecode # used by the interpreter to see if it is resolved.
 224       // We set bytecode_2() to _invokevirtual.
 225       // See also interpreterRuntime.cpp. (8/25/2000)
 226       // Only set resolved for the invokeinterface case if method is public.
 227       // Otherwise, the method needs to be reresolved with caller for each
 228       // interface call.
 229       if (method->is_public()) set_bytecode_1(invoke_code);
 230     } else {
 231       assert(invoke_code == Bytecodes::_invokevirtual, "");
 232     }
 233     // set up for invokevirtual, even if linking for invokeinterface also:
 234     set_bytecode_2(Bytecodes::_invokevirtual);
 235   } else {
 236     ShouldNotReachHere();
 237   }
 238   NOT_PRODUCT(verify(tty));
 239 }
 240 
 241 void ConstantPoolCacheEntry::set_direct_call(Bytecodes::Code invoke_code, methodHandle method) {
 242   int index = Method::nonvirtual_vtable_index;
 243   // index < 0; FIXME: inline and customize set_direct_or_vtable_call
 244   set_direct_or_vtable_call(invoke_code, method, index);
 245 }
 246 
 247 void ConstantPoolCacheEntry::set_vtable_call(Bytecodes::Code invoke_code, methodHandle method, int index) {
 248   // either the method is a miranda or its holder should accept the given index
 249   assert(method->method_holder()->is_interface() || method->method_holder()->verify_vtable_index(index), "");
 250   // index >= 0; FIXME: inline and customize set_direct_or_vtable_call
 251   set_direct_or_vtable_call(invoke_code, method, index);
 252 }
 253 
 254 void ConstantPoolCacheEntry::set_itable_call(Bytecodes::Code invoke_code, methodHandle method, int index) {
 255   assert(method->method_holder()->verify_itable_index(index), "");
 256   assert(invoke_code == Bytecodes::_invokeinterface, "");
 257   InstanceKlass* interf = method->method_holder();
 258   assert(interf->is_interface(), "must be an interface");
 259   assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");
 260   set_f1(interf);
 261   set_f2(index);
 262   set_method_flags(as_TosState(method->result_type()),
 263                    0,  // no option bits
 264                    method()->size_of_parameters());
 265   set_bytecode_1(Bytecodes::_invokeinterface);
 266 }
 267 
 268 
 269 void ConstantPoolCacheEntry::set_method_handle(constantPoolHandle cpool, const CallInfo &call_info) {
 270   set_method_handle_common(cpool, Bytecodes::_invokehandle, call_info);
 271 }
 272 
 273 void ConstantPoolCacheEntry::set_dynamic_call(constantPoolHandle cpool, const CallInfo &call_info) {
 274   set_method_handle_common(cpool, Bytecodes::_invokedynamic, call_info);
 275 }
 276 
 277 void ConstantPoolCacheEntry::set_method_handle_common(constantPoolHandle cpool,
 278                                                       Bytecodes::Code invoke_code,
 279                                                       const CallInfo &call_info) {
 280   // NOTE: This CPCE can be the subject of data races.
 281   // There are three words to update: flags, refs[f2], f1 (in that order).
 282   // Writers must store all other values before f1.
 283   // Readers must test f1 first for non-null before reading other fields.
 284   // Competing writers must acquire exclusive access via a lock.
 285   // A losing writer waits on the lock until the winner writes f1 and leaves
 286   // the lock, so that when the losing writer returns, he can use the linked
 287   // cache entry.
 288 
 289   MonitorLockerEx ml(cpool->lock());
 290   if (!is_f1_null()) {
 291     return;
 292   }
 293 
 294   const methodHandle adapter = call_info.resolved_method();
 295   const Handle appendix      = call_info.resolved_appendix();
 296   const Handle method_type   = call_info.resolved_method_type();
 297   const bool has_appendix    = appendix.not_null();
 298   const bool has_method_type = method_type.not_null();
 299 
 300   // Write the flags.
 301   set_method_flags(as_TosState(adapter->result_type()),
 302                    ((has_appendix    ? 1 : 0) << has_appendix_shift   ) |
 303                    ((has_method_type ? 1 : 0) << has_method_type_shift) |
 304                    (                   1      << is_final_shift       ),
 305                    adapter->size_of_parameters());
 306 
 307   if (TraceInvokeDynamic) {
 308     tty->print_cr("set_method_handle bc=%d appendix="PTR_FORMAT"%s method_type="PTR_FORMAT"%s method="PTR_FORMAT" ",
 309                   invoke_code,
 310                   (void *)appendix(),    (has_appendix    ? "" : " (unused)"),
 311                   (void *)method_type(), (has_method_type ? "" : " (unused)"),
 312                   (intptr_t)adapter());
 313     adapter->print();
 314     if (has_appendix)  appendix()->print();
 315   }
 316 
 317   // Method handle invokes and invokedynamic sites use both cp cache words.
 318   // refs[f2], if not null, contains a value passed as a trailing argument to the adapter.
 319   // In the general case, this could be the call site's MethodType,
 320   // for use with java.lang.Invokers.checkExactType, or else a CallSite object.
 321   // f1 contains the adapter method which manages the actual call.
 322   // In the general case, this is a compiled LambdaForm.
 323   // (The Java code is free to optimize these calls by binding other
 324   // sorts of methods and appendices to call sites.)
 325   // JVM-level linking is via f1, as if for invokespecial, and signatures are erased.
 326   // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.
 327   // Even with the appendix, the method will never take more than 255 parameter slots.
 328   //
 329   // This means that given a call site like (List)mh.invoke("foo"),
 330   // the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;',
 331   // not '(Ljava/lang/String;)Ljava/util/List;'.
 332   // The fact that String and List are involved is encoded in the MethodType in refs[f2].
 333   // This allows us to create fewer method oops, while keeping type safety.
 334   //
 335 
 336   objArrayHandle resolved_references = cpool->resolved_references();
 337   // Store appendix, if any.
 338   if (has_appendix) {
 339     const int appendix_index = f2_as_index() + _indy_resolved_references_appendix_offset;
 340     assert(appendix_index >= 0 && appendix_index < resolved_references->length(), "oob");
 341     assert(resolved_references->obj_at(appendix_index) == NULL, "init just once");
 342     resolved_references->obj_at_put(appendix_index, appendix());
 343   }
 344 
 345   // Store MethodType, if any.
 346   if (has_method_type) {
 347     const int method_type_index = f2_as_index() + _indy_resolved_references_method_type_offset;
 348     assert(method_type_index >= 0 && method_type_index < resolved_references->length(), "oob");
 349     assert(resolved_references->obj_at(method_type_index) == NULL, "init just once");
 350     resolved_references->obj_at_put(method_type_index, method_type());
 351   }
 352 
 353   release_set_f1(adapter());  // This must be the last one to set (see NOTE above)!
 354 
 355   // The interpreter assembly code does not check byte_2,
 356   // but it is used by is_resolved, method_if_resolved, etc.
 357   set_bytecode_1(invoke_code);
 358   NOT_PRODUCT(verify(tty));
 359   if (TraceInvokeDynamic) {
 360     this->print(tty, 0);
 361   }
 362 }
 363 
 364 Method* ConstantPoolCacheEntry::method_if_resolved(constantPoolHandle cpool) {
 365   // Decode the action of set_method and set_interface_call
 366   Bytecodes::Code invoke_code = bytecode_1();
 367   if (invoke_code != (Bytecodes::Code)0) {
 368     Metadata* f1 = f1_ord();
 369     if (f1 != NULL) {
 370       switch (invoke_code) {
 371       case Bytecodes::_invokeinterface:
 372         assert(f1->is_klass(), "");
 373         return klassItable::method_for_itable_index((Klass*)f1, f2_as_index());
 374       case Bytecodes::_invokestatic:
 375       case Bytecodes::_invokespecial:
 376         assert(!has_appendix(), "");
 377       case Bytecodes::_invokehandle:
 378       case Bytecodes::_invokedynamic:
 379         assert(f1->is_method(), "");
 380         return (Method*)f1;
 381       }
 382     }
 383   }
 384   invoke_code = bytecode_2();
 385   if (invoke_code != (Bytecodes::Code)0) {
 386     switch (invoke_code) {
 387     case Bytecodes::_invokevirtual:
 388       if (is_vfinal()) {
 389         // invokevirtual
 390         Method* m = f2_as_vfinal_method();
 391         assert(m->is_method(), "");
 392         return m;
 393       } else {
 394         int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index());
 395         if (cpool->tag_at(holder_index).is_klass()) {
 396           Klass* klass = cpool->resolved_klass_at(holder_index);
 397           if (!klass->oop_is_instance())
 398             klass = SystemDictionary::Object_klass();
 399           return InstanceKlass::cast(klass)->method_at_vtable(f2_as_index());
 400         }
 401       }
 402       break;
 403     }
 404   }
 405   return NULL;
 406 }
 407 
 408 
 409 oop ConstantPoolCacheEntry::appendix_if_resolved(constantPoolHandle cpool) {
 410   if (!has_appendix())
 411     return NULL;
 412   const int ref_index = f2_as_index() + _indy_resolved_references_appendix_offset;
 413   objArrayOop resolved_references = cpool->resolved_references();
 414   return resolved_references->obj_at(ref_index);
 415 }
 416 
 417 
 418 oop ConstantPoolCacheEntry::method_type_if_resolved(constantPoolHandle cpool) {
 419   if (!has_method_type())
 420     return NULL;
 421   const int ref_index = f2_as_index() + _indy_resolved_references_method_type_offset;
 422   objArrayOop resolved_references = cpool->resolved_references();
 423   return resolved_references->obj_at(ref_index);
 424 }
 425 
 426 
 427 #if INCLUDE_JVMTI
 428 // RedefineClasses() API support:
 429 // If this ConstantPoolCacheEntry refers to old_method then update it
 430 // to refer to new_method.
 431 bool ConstantPoolCacheEntry::adjust_method_entry(Method* old_method,
 432        Method* new_method, bool * trace_name_printed) {
 433 
 434   if (is_vfinal()) {
 435     // virtual and final so _f2 contains method ptr instead of vtable index
 436     if (f2_as_vfinal_method() == old_method) {
 437       // match old_method so need an update
 438       // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values
 439       _f2 = (intptr_t)new_method;
 440       if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
 441         if (!(*trace_name_printed)) {
 442           // RC_TRACE_MESG macro has an embedded ResourceMark
 443           RC_TRACE_MESG(("adjust: name=%s",
 444             old_method->method_holder()->external_name()));
 445           *trace_name_printed = true;
 446         }
 447         // RC_TRACE macro has an embedded ResourceMark
 448         RC_TRACE(0x00400000, ("cpc vf-entry update: %s(%s)",
 449           new_method->name()->as_C_string(),
 450           new_method->signature()->as_C_string()));
 451       }
 452 
 453       return true;
 454     }
 455 
 456     // f1() is not used with virtual entries so bail out
 457     return false;
 458   }
 459 
 460   if (_f1 == NULL) {
 461     // NULL f1() means this is a virtual entry so bail out
 462     // We are assuming that the vtable index does not need change.
 463     return false;
 464   }
 465 
 466   if (_f1 == old_method) {
 467     _f1 = new_method;
 468     if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
 469       if (!(*trace_name_printed)) {
 470         // RC_TRACE_MESG macro has an embedded ResourceMark
 471         RC_TRACE_MESG(("adjust: name=%s",
 472           old_method->method_holder()->external_name()));
 473         *trace_name_printed = true;
 474       }
 475       // RC_TRACE macro has an embedded ResourceMark
 476       RC_TRACE(0x00400000, ("cpc entry update: %s(%s)",
 477         new_method->name()->as_C_string(),
 478         new_method->signature()->as_C_string()));
 479     }
 480 
 481     return true;
 482   }
 483 
 484   return false;
 485 }
 486 
 487 // a constant pool cache entry should never contain old or obsolete methods
 488 bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() {
 489   if (is_vfinal()) {
 490     // virtual and final so _f2 contains method ptr instead of vtable index
 491     Metadata* f2 = (Metadata*)_f2;
 492     // Return false if _f2 refers to an old or an obsolete method.
 493     // _f2 == NULL || !_f2->is_method() are just as unexpected here.
 494     return (f2 != NULL NOT_PRODUCT(&& f2->is_valid()) && f2->is_method() &&
 495             !((Method*)f2)->is_old() && !((Method*)f2)->is_obsolete());
 496   } else if (_f1 == NULL ||
 497              (NOT_PRODUCT(_f1->is_valid() &&) !_f1->is_method())) {
 498     // _f1 == NULL || !_f1->is_method() are OK here
 499     return true;
 500   }
 501   // return false if _f1 refers to an old or an obsolete method
 502   return (NOT_PRODUCT(_f1->is_valid() &&) _f1->is_method() &&
 503           !((Method*)_f1)->is_old() && !((Method*)_f1)->is_obsolete());
 504 }
 505 
 506 bool ConstantPoolCacheEntry::is_interesting_method_entry(Klass* k) {
 507   if (!is_method_entry()) {
 508     // not a method entry so not interesting by default
 509     return false;
 510   }
 511 
 512   Method* m = NULL;
 513   if (is_vfinal()) {
 514     // virtual and final so _f2 contains method ptr instead of vtable index
 515     m = f2_as_vfinal_method();
 516   } else if (is_f1_null()) {
 517     // NULL _f1 means this is a virtual entry so also not interesting
 518     return false;
 519   } else {
 520     if (!(_f1->is_method())) {
 521       // _f1 can also contain a Klass* for an interface
 522       return false;
 523     }
 524     m = f1_as_method();
 525   }
 526 
 527   assert(m != NULL && m->is_method(), "sanity check");
 528   if (m == NULL || !m->is_method() || (k != NULL && m->method_holder() != k)) {
 529     // robustness for above sanity checks or method is not in
 530     // the interesting class
 531     return false;
 532   }
 533 
 534   // the method is in the interesting class so the entry is interesting
 535   return true;
 536 }
 537 #endif // INCLUDE_JVMTI
 538 
 539 void ConstantPoolCacheEntry::print(outputStream* st, int index) const {
 540   // print separator
 541   if (index == 0) st->print_cr("                 -------------");
 542   // print entry
 543   st->print("%3d  ("PTR_FORMAT")  ", index, (intptr_t)this);
 544   st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(),
 545                constant_pool_index());
 546   st->print_cr("                 [   "PTR_FORMAT"]", (intptr_t)_f1);
 547   st->print_cr("                 [   "PTR_FORMAT"]", (intptr_t)_f2);
 548   st->print_cr("                 [   "PTR_FORMAT"]", (intptr_t)_flags);
 549   st->print_cr("                 -------------");
 550 }
 551 
 552 void ConstantPoolCacheEntry::verify(outputStream* st) const {
 553   // not implemented yet
 554 }
 555 
 556 // Implementation of ConstantPoolCache
 557 
 558 ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data,
 559                                      const intStack& index_map,
 560                                      const intStack& invokedynamic_index_map,
 561                                      const intStack& invokedynamic_map, TRAPS) {
 562 
 563   const int length = index_map.length() + invokedynamic_index_map.length();
 564   int size = ConstantPoolCache::size(length);
 565 
 566   return new (loader_data, size, false, MetaspaceObj::ConstantPoolCacheType, THREAD)
 567     ConstantPoolCache(length, index_map, invokedynamic_index_map, invokedynamic_map);
 568 }
 569 
 570 void ConstantPoolCache::initialize(const intArray& inverse_index_map,
 571                                    const intArray& invokedynamic_inverse_index_map,
 572                                    const intArray& invokedynamic_references_map) {
 573   for (int i = 0; i < inverse_index_map.length(); i++) {
 574     ConstantPoolCacheEntry* e = entry_at(i);
 575     int original_index = inverse_index_map[i];
 576     e->initialize_entry(original_index);
 577     assert(entry_at(i) == e, "sanity");
 578   }
 579 
 580   // Append invokedynamic entries at the end
 581   int invokedynamic_offset = inverse_index_map.length();
 582   for (int i = 0; i < invokedynamic_inverse_index_map.length(); i++) {
 583     int offset = i + invokedynamic_offset;
 584     ConstantPoolCacheEntry* e = entry_at(offset);
 585     int original_index = invokedynamic_inverse_index_map[i];
 586     e->initialize_entry(original_index);
 587     assert(entry_at(offset) == e, "sanity");
 588   }
 589 
 590   for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) {
 591     const int cpci = invokedynamic_references_map[ref];
 592     if (cpci >= 0) {
 593 #ifdef ASSERT
 594       // invokedynamic and invokehandle have more entries; check if they
 595       // all point to the same constant pool cache entry.
 596       for (int entry = 1; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) {
 597         const int cpci_next = invokedynamic_references_map[ref + entry];
 598         assert(cpci == cpci_next, err_msg_res("%d == %d", cpci, cpci_next));
 599       }
 600 #endif
 601       entry_at(cpci)->initialize_resolved_reference_index(ref);
 602       ref += ConstantPoolCacheEntry::_indy_resolved_references_entries - 1;  // skip extra entries
 603     }
 604   }
 605 }
 606 
 607 #if INCLUDE_JVMTI
 608 // RedefineClasses() API support:
 609 // If any entry of this ConstantPoolCache points to any of
 610 // old_methods, replace it with the corresponding new_method.
 611 void ConstantPoolCache::adjust_method_entries(Method** old_methods, Method** new_methods,
 612                                                      int methods_length, bool * trace_name_printed) {
 613 
 614   if (methods_length == 0) {
 615     // nothing to do if there are no methods
 616     return;
 617   }
 618 
 619   // get shorthand for the interesting class
 620   Klass* old_holder = old_methods[0]->method_holder();
 621 
 622   for (int i = 0; i < length(); i++) {
 623     if (!entry_at(i)->is_interesting_method_entry(old_holder)) {
 624       // skip uninteresting methods
 625       continue;
 626     }
 627 
 628     // The ConstantPoolCache contains entries for several different
 629     // things, but we only care about methods. In fact, we only care
 630     // about methods in the same class as the one that contains the
 631     // old_methods. At this point, we have an interesting entry.
 632 
 633     for (int j = 0; j < methods_length; j++) {
 634       Method* old_method = old_methods[j];
 635       Method* new_method = new_methods[j];
 636 
 637       if (entry_at(i)->adjust_method_entry(old_method, new_method,
 638           trace_name_printed)) {
 639         // current old_method matched this entry and we updated it so
 640         // break out and get to the next interesting entry if there one
 641         break;
 642       }
 643     }
 644   }
 645 }
 646 
 647 // the constant pool cache should never contain old or obsolete methods
 648 bool ConstantPoolCache::check_no_old_or_obsolete_entries() {
 649   for (int i = 1; i < length(); i++) {
 650     if (entry_at(i)->is_interesting_method_entry(NULL) &&
 651         !entry_at(i)->check_no_old_or_obsolete_entries()) {
 652       return false;
 653     }
 654   }
 655   return true;
 656 }
 657 
 658 void ConstantPoolCache::dump_cache() {
 659   for (int i = 1; i < length(); i++) {
 660     if (entry_at(i)->is_interesting_method_entry(NULL)) {
 661       entry_at(i)->print(tty, i);
 662     }
 663   }
 664 }
 665 #endif // INCLUDE_JVMTI
 666 
 667 
 668 // Printing
 669 
 670 void ConstantPoolCache::print_on(outputStream* st) const {
 671   assert(is_constantPoolCache(), "obj must be constant pool cache");
 672   st->print_cr("%s", internal_name());
 673   // print constant pool cache entries
 674   for (int i = 0; i < length(); i++) entry_at(i)->print(st, i);
 675 }
 676 
 677 void ConstantPoolCache::print_value_on(outputStream* st) const {
 678   assert(is_constantPoolCache(), "obj must be constant pool cache");
 679   st->print("cache [%d]", length());
 680   print_address_on(st);
 681   st->print(" for ");
 682   constant_pool()->print_value_on(st);
 683 }
 684 
 685 
 686 // Verification
 687 
 688 void ConstantPoolCache::verify_on(outputStream* st) {
 689   guarantee(is_constantPoolCache(), "obj must be constant pool cache");
 690   // print constant pool cache entries
 691   for (int i = 0; i < length(); i++) entry_at(i)->verify(st);
 692 }