src/share/vm/oops/constantPool.cpp

Fri, 20 Sep 2013 09:30:02 -0400

author
coleenp
date
Fri, 20 Sep 2013 09:30:02 -0400
changeset 5749
4f9a42c33738
parent 5307
e0c9a1d29eb4
child 5732
b2e698d2276c
child 5753
7c29904fdfa2
permissions
-rw-r--r--

8022887: Assertion hit while using class and redefining it with RedefineClasses simultaneously
Summary: Need to refetch each method from InstanceKlass after all safepoints. Removed leaky PreviousVersionInfo code.
Reviewed-by: dcubed, sspitsyn

     1 /*
     2  * Copyright (c) 1997, 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  */
    25 #include "precompiled.hpp"
    26 #include "classfile/classLoaderData.hpp"
    27 #include "classfile/javaClasses.hpp"
    28 #include "classfile/metadataOnStackMark.hpp"
    29 #include "classfile/symbolTable.hpp"
    30 #include "classfile/systemDictionary.hpp"
    31 #include "classfile/vmSymbols.hpp"
    32 #include "interpreter/linkResolver.hpp"
    33 #include "memory/heapInspection.hpp"
    34 #include "memory/metadataFactory.hpp"
    35 #include "memory/oopFactory.hpp"
    36 #include "oops/constantPool.hpp"
    37 #include "oops/instanceKlass.hpp"
    38 #include "oops/objArrayKlass.hpp"
    39 #include "runtime/fieldType.hpp"
    40 #include "runtime/init.hpp"
    41 #include "runtime/javaCalls.hpp"
    42 #include "runtime/signature.hpp"
    43 #include "runtime/synchronizer.hpp"
    44 #include "runtime/vframe.hpp"
    46 ConstantPool* ConstantPool::allocate(ClassLoaderData* loader_data, int length, TRAPS) {
    47   // Tags are RW but comment below applies to tags also.
    48   Array<u1>* tags = MetadataFactory::new_writeable_array<u1>(loader_data, length, 0, CHECK_NULL);
    50   int size = ConstantPool::size(length);
    52   // CDS considerations:
    53   // Allocate read-write but may be able to move to read-only at dumping time
    54   // if all the klasses are resolved.  The only other field that is writable is
    55   // the resolved_references array, which is recreated at startup time.
    56   // But that could be moved to InstanceKlass (although a pain to access from
    57   // assembly code).  Maybe it could be moved to the cpCache which is RW.
    58   return new (loader_data, size, false, MetaspaceObj::ConstantPoolType, THREAD) ConstantPool(tags);
    59 }
    61 ConstantPool::ConstantPool(Array<u1>* tags) {
    62   set_length(tags->length());
    63   set_tags(NULL);
    64   set_cache(NULL);
    65   set_reference_map(NULL);
    66   set_resolved_references(NULL);
    67   set_operands(NULL);
    68   set_pool_holder(NULL);
    69   set_flags(0);
    71   // only set to non-zero if constant pool is merged by RedefineClasses
    72   set_version(0);
    74   // initialize tag array
    75   int length = tags->length();
    76   for (int index = 0; index < length; index++) {
    77     tags->at_put(index, JVM_CONSTANT_Invalid);
    78   }
    79   set_tags(tags);
    80 }
    82 void ConstantPool::deallocate_contents(ClassLoaderData* loader_data) {
    83   MetadataFactory::free_metadata(loader_data, cache());
    84   set_cache(NULL);
    85   MetadataFactory::free_array<jushort>(loader_data, operands());
    86   set_operands(NULL);
    88   release_C_heap_structures();
    90   // free tag array
    91   MetadataFactory::free_array<u1>(loader_data, tags());
    92   set_tags(NULL);
    93 }
    95 void ConstantPool::release_C_heap_structures() {
    96   // walk constant pool and decrement symbol reference counts
    97   unreference_symbols();
    98 }
   100 objArrayOop ConstantPool::resolved_references() const {
   101   return (objArrayOop)JNIHandles::resolve(_resolved_references);
   102 }
   104 // Create resolved_references array and mapping array for original cp indexes
   105 // The ldc bytecode was rewritten to have the resolved reference array index so need a way
   106 // to map it back for resolving and some unlikely miscellaneous uses.
   107 // The objects created by invokedynamic are appended to this list.
   108 void ConstantPool::initialize_resolved_references(ClassLoaderData* loader_data,
   109                                                   intStack reference_map,
   110                                                   int constant_pool_map_length,
   111                                                    TRAPS) {
   112   // Initialized the resolved object cache.
   113   int map_length = reference_map.length();
   114   if (map_length > 0) {
   115     // Only need mapping back to constant pool entries.  The map isn't used for
   116     // invokedynamic resolved_reference entries.  The constant pool cache index
   117     // has the mapping back to both the constant pool and to the resolved
   118     // reference index.
   119     if (constant_pool_map_length > 0) {
   120       Array<u2>* om = MetadataFactory::new_array<u2>(loader_data, map_length, CHECK);
   122       for (int i = 0; i < constant_pool_map_length; i++) {
   123         int x = reference_map.at(i);
   124         assert(x == (int)(jushort) x, "klass index is too big");
   125         om->at_put(i, (jushort)x);
   126       }
   127       set_reference_map(om);
   128     }
   130     // Create Java array for holding resolved strings, methodHandles,
   131     // methodTypes, invokedynamic and invokehandle appendix objects, etc.
   132     objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
   133     Handle refs_handle (THREAD, (oop)stom);  // must handleize.
   134     set_resolved_references(loader_data->add_handle(refs_handle));
   135   }
   136 }
   138 // CDS support. Create a new resolved_references array.
   139 void ConstantPool::restore_unshareable_info(TRAPS) {
   141   // restore the C++ vtable from the shared archive
   142   restore_vtable();
   144   if (SystemDictionary::Object_klass_loaded()) {
   145     // Recreate the object array and add to ClassLoaderData.
   146     int map_length = resolved_reference_length();
   147     if (map_length > 0) {
   148       objArrayOop stom = oopFactory::new_objArray(SystemDictionary::Object_klass(), map_length, CHECK);
   149       Handle refs_handle (THREAD, (oop)stom);  // must handleize.
   151       ClassLoaderData* loader_data = pool_holder()->class_loader_data();
   152       set_resolved_references(loader_data->add_handle(refs_handle));
   153     }
   154   }
   155 }
   157 void ConstantPool::remove_unshareable_info() {
   158   // Resolved references are not in the shared archive.
   159   // Save the length for restoration.  It is not necessarily the same length
   160   // as reference_map.length() if invokedynamic is saved.
   161   set_resolved_reference_length(
   162     resolved_references() != NULL ? resolved_references()->length() : 0);
   163   set_resolved_references(NULL);
   164 }
   166 oop ConstantPool::lock() {
   167   if (_pool_holder) {
   168     // We re-use the _pool_holder's init_lock to reduce footprint.
   169     // Notes on deadlocks:
   170     // [1] This lock is a Java oop, so it can be recursively locked by
   171     //     the same thread without self-deadlocks.
   172     // [2] Deadlock will happen if there is circular dependency between
   173     //     the <clinit> of two Java classes. However, in this case,
   174     //     the deadlock would have happened long before we reach
   175     //     ConstantPool::lock(), so reusing init_lock does not
   176     //     increase the possibility of deadlock.
   177     return _pool_holder->init_lock();
   178   } else {
   179     return NULL;
   180   }
   181 }
   183 int ConstantPool::cp_to_object_index(int cp_index) {
   184   // this is harder don't do this so much.
   185   for (int i = 0; i< reference_map()->length(); i++) {
   186     if (reference_map()->at(i) == cp_index) return i;
   187     // Zero entry is divider between constant pool indices for strings,
   188     // method handles and method types. After that the index is a constant
   189     // pool cache index for invokedynamic.  Stop when zero (which can never
   190     // be a constant pool index)
   191     if (reference_map()->at(i) == 0) break;
   192   }
   193   // We might not find the index.
   194   return _no_index_sentinel;
   195 }
   197 Klass* ConstantPool::klass_at_impl(constantPoolHandle this_oop, int which, TRAPS) {
   198   // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
   199   // It is not safe to rely on the tag bit's here, since we don't have a lock, and the entry and
   200   // tag is not updated atomicly.
   202   CPSlot entry = this_oop->slot_at(which);
   203   if (entry.is_resolved()) {
   204     assert(entry.get_klass()->is_klass(), "must be");
   205     // Already resolved - return entry.
   206     return entry.get_klass();
   207   }
   209   // Acquire lock on constant oop while doing update. After we get the lock, we check if another object
   210   // already has updated the object
   211   assert(THREAD->is_Java_thread(), "must be a Java thread");
   212   bool do_resolve = false;
   213   bool in_error = false;
   215   // Create a handle for the mirror. This will preserve the resolved class
   216   // until the loader_data is registered.
   217   Handle mirror_handle;
   219   Symbol* name = NULL;
   220   Handle       loader;
   221   {
   222     oop cplock = this_oop->lock();
   223     ObjectLocker ol(cplock , THREAD, cplock != NULL);
   225     if (this_oop->tag_at(which).is_unresolved_klass()) {
   226       if (this_oop->tag_at(which).is_unresolved_klass_in_error()) {
   227         in_error = true;
   228       } else {
   229         do_resolve = true;
   230         name   = this_oop->unresolved_klass_at(which);
   231         loader = Handle(THREAD, this_oop->pool_holder()->class_loader());
   232       }
   233     }
   234   } // unlocking constantPool
   237   // The original attempt to resolve this constant pool entry failed so find the
   238   // original error and throw it again (JVMS 5.4.3).
   239   if (in_error) {
   240     Symbol* error = SystemDictionary::find_resolution_error(this_oop, which);
   241     guarantee(error != (Symbol*)NULL, "tag mismatch with resolution error table");
   242     ResourceMark rm;
   243     // exception text will be the class name
   244     const char* className = this_oop->unresolved_klass_at(which)->as_C_string();
   245     THROW_MSG_0(error, className);
   246   }
   248   if (do_resolve) {
   249     // this_oop must be unlocked during resolve_or_fail
   250     oop protection_domain = this_oop->pool_holder()->protection_domain();
   251     Handle h_prot (THREAD, protection_domain);
   252     Klass* k_oop = SystemDictionary::resolve_or_fail(name, loader, h_prot, true, THREAD);
   253     KlassHandle k;
   254     if (!HAS_PENDING_EXCEPTION) {
   255       k = KlassHandle(THREAD, k_oop);
   256       // preserve the resolved klass.
   257       mirror_handle = Handle(THREAD, k_oop->java_mirror());
   258       // Do access check for klasses
   259       verify_constant_pool_resolve(this_oop, k, THREAD);
   260     }
   262     // Failed to resolve class. We must record the errors so that subsequent attempts
   263     // to resolve this constant pool entry fail with the same error (JVMS 5.4.3).
   264     if (HAS_PENDING_EXCEPTION) {
   265       ResourceMark rm;
   266       Symbol* error = PENDING_EXCEPTION->klass()->name();
   268       bool throw_orig_error = false;
   269       {
   270         oop cplock = this_oop->lock();
   271         ObjectLocker ol(cplock, THREAD, cplock != NULL);
   273         // some other thread has beaten us and has resolved the class.
   274         if (this_oop->tag_at(which).is_klass()) {
   275           CLEAR_PENDING_EXCEPTION;
   276           entry = this_oop->resolved_klass_at(which);
   277           return entry.get_klass();
   278         }
   280         if (!PENDING_EXCEPTION->
   281               is_a(SystemDictionary::LinkageError_klass())) {
   282           // Just throw the exception and don't prevent these classes from
   283           // being loaded due to virtual machine errors like StackOverflow
   284           // and OutOfMemoryError, etc, or if the thread was hit by stop()
   285           // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
   286         }
   287         else if (!this_oop->tag_at(which).is_unresolved_klass_in_error()) {
   288           SystemDictionary::add_resolution_error(this_oop, which, error);
   289           this_oop->tag_at_put(which, JVM_CONSTANT_UnresolvedClassInError);
   290         } else {
   291           // some other thread has put the class in error state.
   292           error = SystemDictionary::find_resolution_error(this_oop, which);
   293           assert(error != NULL, "checking");
   294           throw_orig_error = true;
   295         }
   296       } // unlocked
   298       if (throw_orig_error) {
   299         CLEAR_PENDING_EXCEPTION;
   300         ResourceMark rm;
   301         const char* className = this_oop->unresolved_klass_at(which)->as_C_string();
   302         THROW_MSG_0(error, className);
   303       }
   305       return 0;
   306     }
   308     if (TraceClassResolution && !k()->oop_is_array()) {
   309       // skip resolving the constant pool so that this code get's
   310       // called the next time some bytecodes refer to this class.
   311       ResourceMark rm;
   312       int line_number = -1;
   313       const char * source_file = NULL;
   314       if (JavaThread::current()->has_last_Java_frame()) {
   315         // try to identify the method which called this function.
   316         vframeStream vfst(JavaThread::current());
   317         if (!vfst.at_end()) {
   318           line_number = vfst.method()->line_number_from_bci(vfst.bci());
   319           Symbol* s = vfst.method()->method_holder()->source_file_name();
   320           if (s != NULL) {
   321             source_file = s->as_C_string();
   322           }
   323         }
   324       }
   325       if (k() != this_oop->pool_holder()) {
   326         // only print something if the classes are different
   327         if (source_file != NULL) {
   328           tty->print("RESOLVE %s %s %s:%d\n",
   329                      this_oop->pool_holder()->external_name(),
   330                      InstanceKlass::cast(k())->external_name(), source_file, line_number);
   331         } else {
   332           tty->print("RESOLVE %s %s\n",
   333                      this_oop->pool_holder()->external_name(),
   334                      InstanceKlass::cast(k())->external_name());
   335         }
   336       }
   337       return k();
   338     } else {
   339       oop cplock = this_oop->lock();
   340       ObjectLocker ol(cplock, THREAD, cplock != NULL);
   341       // Only updated constant pool - if it is resolved.
   342       do_resolve = this_oop->tag_at(which).is_unresolved_klass();
   343       if (do_resolve) {
   344         ClassLoaderData* this_key = this_oop->pool_holder()->class_loader_data();
   345         this_key->record_dependency(k(), CHECK_NULL); // Can throw OOM
   346         this_oop->klass_at_put(which, k());
   347       }
   348     }
   349   }
   351   entry = this_oop->resolved_klass_at(which);
   352   assert(entry.is_resolved() && entry.get_klass()->is_klass(), "must be resolved at this point");
   353   return entry.get_klass();
   354 }
   357 // Does not update ConstantPool* - to avoid any exception throwing. Used
   358 // by compiler and exception handling.  Also used to avoid classloads for
   359 // instanceof operations. Returns NULL if the class has not been loaded or
   360 // if the verification of constant pool failed
   361 Klass* ConstantPool::klass_at_if_loaded(constantPoolHandle this_oop, int which) {
   362   CPSlot entry = this_oop->slot_at(which);
   363   if (entry.is_resolved()) {
   364     assert(entry.get_klass()->is_klass(), "must be");
   365     return entry.get_klass();
   366   } else {
   367     assert(entry.is_unresolved(), "must be either symbol or klass");
   368     Thread *thread = Thread::current();
   369     Symbol* name = entry.get_symbol();
   370     oop loader = this_oop->pool_holder()->class_loader();
   371     oop protection_domain = this_oop->pool_holder()->protection_domain();
   372     Handle h_prot (thread, protection_domain);
   373     Handle h_loader (thread, loader);
   374     Klass* k = SystemDictionary::find(name, h_loader, h_prot, thread);
   376     if (k != NULL) {
   377       // Make sure that resolving is legal
   378       EXCEPTION_MARK;
   379       KlassHandle klass(THREAD, k);
   380       // return NULL if verification fails
   381       verify_constant_pool_resolve(this_oop, klass, THREAD);
   382       if (HAS_PENDING_EXCEPTION) {
   383         CLEAR_PENDING_EXCEPTION;
   384         return NULL;
   385       }
   386       return klass();
   387     } else {
   388       return k;
   389     }
   390   }
   391 }
   394 Klass* ConstantPool::klass_ref_at_if_loaded(constantPoolHandle this_oop, int which) {
   395   return klass_at_if_loaded(this_oop, this_oop->klass_ref_index_at(which));
   396 }
   399 // This is an interface for the compiler that allows accessing non-resolved entries
   400 // in the constant pool - but still performs the validations tests. Must be used
   401 // in a pre-parse of the compiler - to determine what it can do and not do.
   402 // Note: We cannot update the ConstantPool from the vm_thread.
   403 Klass* ConstantPool::klass_ref_at_if_loaded_check(constantPoolHandle this_oop, int index, TRAPS) {
   404   int which = this_oop->klass_ref_index_at(index);
   405   CPSlot entry = this_oop->slot_at(which);
   406   if (entry.is_resolved()) {
   407     assert(entry.get_klass()->is_klass(), "must be");
   408     return entry.get_klass();
   409   } else {
   410     assert(entry.is_unresolved(), "must be either symbol or klass");
   411     Symbol*  name  = entry.get_symbol();
   412     oop loader = this_oop->pool_holder()->class_loader();
   413     oop protection_domain = this_oop->pool_holder()->protection_domain();
   414     Handle h_loader(THREAD, loader);
   415     Handle h_prot  (THREAD, protection_domain);
   416     KlassHandle k(THREAD, SystemDictionary::find(name, h_loader, h_prot, THREAD));
   418     // Do access check for klasses
   419     if( k.not_null() ) verify_constant_pool_resolve(this_oop, k, CHECK_NULL);
   420     return k();
   421   }
   422 }
   425 Method* ConstantPool::method_at_if_loaded(constantPoolHandle cpool,
   426                                                    int which) {
   427   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
   428   int cache_index = decode_cpcache_index(which, true);
   429   if (!(cache_index >= 0 && cache_index < cpool->cache()->length())) {
   430     // FIXME: should be an assert
   431     if (PrintMiscellaneous && (Verbose||WizardMode)) {
   432       tty->print_cr("bad operand %d in:", which); cpool->print();
   433     }
   434     return NULL;
   435   }
   436   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
   437   return e->method_if_resolved(cpool);
   438 }
   441 bool ConstantPool::has_appendix_at_if_loaded(constantPoolHandle cpool, int which) {
   442   if (cpool->cache() == NULL)  return false;  // nothing to load yet
   443   int cache_index = decode_cpcache_index(which, true);
   444   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
   445   return e->has_appendix();
   446 }
   448 oop ConstantPool::appendix_at_if_loaded(constantPoolHandle cpool, int which) {
   449   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
   450   int cache_index = decode_cpcache_index(which, true);
   451   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
   452   return e->appendix_if_resolved(cpool);
   453 }
   456 bool ConstantPool::has_method_type_at_if_loaded(constantPoolHandle cpool, int which) {
   457   if (cpool->cache() == NULL)  return false;  // nothing to load yet
   458   int cache_index = decode_cpcache_index(which, true);
   459   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
   460   return e->has_method_type();
   461 }
   463 oop ConstantPool::method_type_at_if_loaded(constantPoolHandle cpool, int which) {
   464   if (cpool->cache() == NULL)  return NULL;  // nothing to load yet
   465   int cache_index = decode_cpcache_index(which, true);
   466   ConstantPoolCacheEntry* e = cpool->cache()->entry_at(cache_index);
   467   return e->method_type_if_resolved(cpool);
   468 }
   471 Symbol* ConstantPool::impl_name_ref_at(int which, bool uncached) {
   472   int name_index = name_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
   473   return symbol_at(name_index);
   474 }
   477 Symbol* ConstantPool::impl_signature_ref_at(int which, bool uncached) {
   478   int signature_index = signature_ref_index_at(impl_name_and_type_ref_index_at(which, uncached));
   479   return symbol_at(signature_index);
   480 }
   483 int ConstantPool::impl_name_and_type_ref_index_at(int which, bool uncached) {
   484   int i = which;
   485   if (!uncached && cache() != NULL) {
   486     if (ConstantPool::is_invokedynamic_index(which)) {
   487       // Invokedynamic index is index into resolved_references
   488       int pool_index = invokedynamic_cp_cache_entry_at(which)->constant_pool_index();
   489       pool_index = invoke_dynamic_name_and_type_ref_index_at(pool_index);
   490       assert(tag_at(pool_index).is_name_and_type(), "");
   491       return pool_index;
   492     }
   493     // change byte-ordering and go via cache
   494     i = remap_instruction_operand_from_cache(which);
   495   } else {
   496     if (tag_at(which).is_invoke_dynamic()) {
   497       int pool_index = invoke_dynamic_name_and_type_ref_index_at(which);
   498       assert(tag_at(pool_index).is_name_and_type(), "");
   499       return pool_index;
   500     }
   501   }
   502   assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
   503   assert(!tag_at(i).is_invoke_dynamic(), "Must be handled above");
   504   jint ref_index = *int_at_addr(i);
   505   return extract_high_short_from_int(ref_index);
   506 }
   509 int ConstantPool::impl_klass_ref_index_at(int which, bool uncached) {
   510   guarantee(!ConstantPool::is_invokedynamic_index(which),
   511             "an invokedynamic instruction does not have a klass");
   512   int i = which;
   513   if (!uncached && cache() != NULL) {
   514     // change byte-ordering and go via cache
   515     i = remap_instruction_operand_from_cache(which);
   516   }
   517   assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
   518   jint ref_index = *int_at_addr(i);
   519   return extract_low_short_from_int(ref_index);
   520 }
   524 int ConstantPool::remap_instruction_operand_from_cache(int operand) {
   525   int cpc_index = operand;
   526   DEBUG_ONLY(cpc_index -= CPCACHE_INDEX_TAG);
   527   assert((int)(u2)cpc_index == cpc_index, "clean u2");
   528   int member_index = cache()->entry_at(cpc_index)->constant_pool_index();
   529   return member_index;
   530 }
   533 void ConstantPool::verify_constant_pool_resolve(constantPoolHandle this_oop, KlassHandle k, TRAPS) {
   534  if (k->oop_is_instance() || k->oop_is_objArray()) {
   535     instanceKlassHandle holder (THREAD, this_oop->pool_holder());
   536     Klass* elem_oop = k->oop_is_instance() ? k() : ObjArrayKlass::cast(k())->bottom_klass();
   537     KlassHandle element (THREAD, elem_oop);
   539     // The element type could be a typeArray - we only need the access check if it is
   540     // an reference to another class
   541     if (element->oop_is_instance()) {
   542       LinkResolver::check_klass_accessability(holder, element, CHECK);
   543     }
   544   }
   545 }
   548 int ConstantPool::name_ref_index_at(int which_nt) {
   549   jint ref_index = name_and_type_at(which_nt);
   550   return extract_low_short_from_int(ref_index);
   551 }
   554 int ConstantPool::signature_ref_index_at(int which_nt) {
   555   jint ref_index = name_and_type_at(which_nt);
   556   return extract_high_short_from_int(ref_index);
   557 }
   560 Klass* ConstantPool::klass_ref_at(int which, TRAPS) {
   561   return klass_at(klass_ref_index_at(which), CHECK_NULL);
   562 }
   565 Symbol* ConstantPool::klass_name_at(int which) {
   566   assert(tag_at(which).is_unresolved_klass() || tag_at(which).is_klass(),
   567          "Corrupted constant pool");
   568   // A resolved constantPool entry will contain a Klass*, otherwise a Symbol*.
   569   // It is not safe to rely on the tag bit's here, since we don't have a lock, and the entry and
   570   // tag is not updated atomicly.
   571   CPSlot entry = slot_at(which);
   572   if (entry.is_resolved()) {
   573     // Already resolved - return entry's name.
   574     assert(entry.get_klass()->is_klass(), "must be");
   575     return entry.get_klass()->name();
   576   } else {
   577     assert(entry.is_unresolved(), "must be either symbol or klass");
   578     return entry.get_symbol();
   579   }
   580 }
   582 Symbol* ConstantPool::klass_ref_at_noresolve(int which) {
   583   jint ref_index = klass_ref_index_at(which);
   584   return klass_at_noresolve(ref_index);
   585 }
   587 Symbol* ConstantPool::uncached_klass_ref_at_noresolve(int which) {
   588   jint ref_index = uncached_klass_ref_index_at(which);
   589   return klass_at_noresolve(ref_index);
   590 }
   592 char* ConstantPool::string_at_noresolve(int which) {
   593   Symbol* s = unresolved_string_at(which);
   594   if (s == NULL) {
   595     return (char*)"<pseudo-string>";
   596   } else {
   597     return unresolved_string_at(which)->as_C_string();
   598   }
   599 }
   601 BasicType ConstantPool::basic_type_for_signature_at(int which) {
   602   return FieldType::basic_type(symbol_at(which));
   603 }
   606 void ConstantPool::resolve_string_constants_impl(constantPoolHandle this_oop, TRAPS) {
   607   for (int index = 1; index < this_oop->length(); index++) { // Index 0 is unused
   608     if (this_oop->tag_at(index).is_string()) {
   609       this_oop->string_at(index, CHECK);
   610     }
   611   }
   612 }
   614 // Resolve all the classes in the constant pool.  If they are all resolved,
   615 // the constant pool is read-only.  Enhancement: allocate cp entries to
   616 // another metaspace, and copy to read-only or read-write space if this
   617 // bit is set.
   618 bool ConstantPool::resolve_class_constants(TRAPS) {
   619   constantPoolHandle cp(THREAD, this);
   620   for (int index = 1; index < length(); index++) { // Index 0 is unused
   621     if (tag_at(index).is_unresolved_klass() &&
   622         klass_at_if_loaded(cp, index) == NULL) {
   623       return false;
   624   }
   625   }
   626   // set_preresolution(); or some bit for future use
   627   return true;
   628 }
   630 // If resolution for MethodHandle or MethodType fails, save the exception
   631 // in the resolution error table, so that the same exception is thrown again.
   632 void ConstantPool::save_and_throw_exception(constantPoolHandle this_oop, int which,
   633                                      int tag, TRAPS) {
   634   ResourceMark rm;
   635   Symbol* error = PENDING_EXCEPTION->klass()->name();
   636   oop cplock = this_oop->lock();
   637   ObjectLocker ol(cplock, THREAD, cplock != NULL);  // lock cpool to change tag.
   639   int error_tag = (tag == JVM_CONSTANT_MethodHandle) ?
   640            JVM_CONSTANT_MethodHandleInError : JVM_CONSTANT_MethodTypeInError;
   642   if (!PENDING_EXCEPTION->
   643     is_a(SystemDictionary::LinkageError_klass())) {
   644     // Just throw the exception and don't prevent these classes from
   645     // being loaded due to virtual machine errors like StackOverflow
   646     // and OutOfMemoryError, etc, or if the thread was hit by stop()
   647     // Needs clarification to section 5.4.3 of the VM spec (see 6308271)
   649   } else if (this_oop->tag_at(which).value() != error_tag) {
   650     SystemDictionary::add_resolution_error(this_oop, which, error);
   651     this_oop->tag_at_put(which, error_tag);
   652   } else {
   653     // some other thread has put the class in error state.
   654     error = SystemDictionary::find_resolution_error(this_oop, which);
   655     assert(error != NULL, "checking");
   656     CLEAR_PENDING_EXCEPTION;
   657     THROW_MSG(error, "");
   658   }
   659 }
   662 // Called to resolve constants in the constant pool and return an oop.
   663 // Some constant pool entries cache their resolved oop. This is also
   664 // called to create oops from constants to use in arguments for invokedynamic
   665 oop ConstantPool::resolve_constant_at_impl(constantPoolHandle this_oop, int index, int cache_index, TRAPS) {
   666   oop result_oop = NULL;
   667   Handle throw_exception;
   669   if (cache_index == _possible_index_sentinel) {
   670     // It is possible that this constant is one which is cached in the objects.
   671     // We'll do a linear search.  This should be OK because this usage is rare.
   672     assert(index > 0, "valid index");
   673     cache_index = this_oop->cp_to_object_index(index);
   674   }
   675   assert(cache_index == _no_index_sentinel || cache_index >= 0, "");
   676   assert(index == _no_index_sentinel || index >= 0, "");
   678   if (cache_index >= 0) {
   679     result_oop = this_oop->resolved_references()->obj_at(cache_index);
   680     if (result_oop != NULL) {
   681       return result_oop;
   682       // That was easy...
   683     }
   684     index = this_oop->object_to_cp_index(cache_index);
   685   }
   687   jvalue prim_value;  // temp used only in a few cases below
   689   int tag_value = this_oop->tag_at(index).value();
   691   switch (tag_value) {
   693   case JVM_CONSTANT_UnresolvedClass:
   694   case JVM_CONSTANT_UnresolvedClassInError:
   695   case JVM_CONSTANT_Class:
   696     {
   697       assert(cache_index == _no_index_sentinel, "should not have been set");
   698       Klass* resolved = klass_at_impl(this_oop, index, CHECK_NULL);
   699       // ldc wants the java mirror.
   700       result_oop = resolved->java_mirror();
   701       break;
   702     }
   704   case JVM_CONSTANT_String:
   705     assert(cache_index != _no_index_sentinel, "should have been set");
   706     if (this_oop->is_pseudo_string_at(index)) {
   707       result_oop = this_oop->pseudo_string_at(index, cache_index);
   708       break;
   709     }
   710     result_oop = string_at_impl(this_oop, index, cache_index, CHECK_NULL);
   711     break;
   713   case JVM_CONSTANT_MethodHandleInError:
   714   case JVM_CONSTANT_MethodTypeInError:
   715     {
   716       Symbol* error = SystemDictionary::find_resolution_error(this_oop, index);
   717       guarantee(error != (Symbol*)NULL, "tag mismatch with resolution error table");
   718       ResourceMark rm;
   719       THROW_MSG_0(error, "");
   720       break;
   721     }
   723   case JVM_CONSTANT_MethodHandle:
   724     {
   725       int ref_kind                 = this_oop->method_handle_ref_kind_at(index);
   726       int callee_index             = this_oop->method_handle_klass_index_at(index);
   727       Symbol*  name =      this_oop->method_handle_name_ref_at(index);
   728       Symbol*  signature = this_oop->method_handle_signature_ref_at(index);
   729       if (PrintMiscellaneous)
   730         tty->print_cr("resolve JVM_CONSTANT_MethodHandle:%d [%d/%d/%d] %s.%s",
   731                       ref_kind, index, this_oop->method_handle_index_at(index),
   732                       callee_index, name->as_C_string(), signature->as_C_string());
   733       KlassHandle callee;
   734       { Klass* k = klass_at_impl(this_oop, callee_index, CHECK_NULL);
   735         callee = KlassHandle(THREAD, k);
   736       }
   737       KlassHandle klass(THREAD, this_oop->pool_holder());
   738       Handle value = SystemDictionary::link_method_handle_constant(klass, ref_kind,
   739                                                                    callee, name, signature,
   740                                                                    THREAD);
   741       result_oop = value();
   742       if (HAS_PENDING_EXCEPTION) {
   743         save_and_throw_exception(this_oop, index, tag_value, CHECK_NULL);
   744       }
   745       break;
   746     }
   748   case JVM_CONSTANT_MethodType:
   749     {
   750       Symbol*  signature = this_oop->method_type_signature_at(index);
   751       if (PrintMiscellaneous)
   752         tty->print_cr("resolve JVM_CONSTANT_MethodType [%d/%d] %s",
   753                       index, this_oop->method_type_index_at(index),
   754                       signature->as_C_string());
   755       KlassHandle klass(THREAD, this_oop->pool_holder());
   756       Handle value = SystemDictionary::find_method_handle_type(signature, klass, THREAD);
   757       result_oop = value();
   758       if (HAS_PENDING_EXCEPTION) {
   759         save_and_throw_exception(this_oop, index, tag_value, CHECK_NULL);
   760       }
   761       break;
   762     }
   764   case JVM_CONSTANT_Integer:
   765     assert(cache_index == _no_index_sentinel, "should not have been set");
   766     prim_value.i = this_oop->int_at(index);
   767     result_oop = java_lang_boxing_object::create(T_INT, &prim_value, CHECK_NULL);
   768     break;
   770   case JVM_CONSTANT_Float:
   771     assert(cache_index == _no_index_sentinel, "should not have been set");
   772     prim_value.f = this_oop->float_at(index);
   773     result_oop = java_lang_boxing_object::create(T_FLOAT, &prim_value, CHECK_NULL);
   774     break;
   776   case JVM_CONSTANT_Long:
   777     assert(cache_index == _no_index_sentinel, "should not have been set");
   778     prim_value.j = this_oop->long_at(index);
   779     result_oop = java_lang_boxing_object::create(T_LONG, &prim_value, CHECK_NULL);
   780     break;
   782   case JVM_CONSTANT_Double:
   783     assert(cache_index == _no_index_sentinel, "should not have been set");
   784     prim_value.d = this_oop->double_at(index);
   785     result_oop = java_lang_boxing_object::create(T_DOUBLE, &prim_value, CHECK_NULL);
   786     break;
   788   default:
   789     DEBUG_ONLY( tty->print_cr("*** %p: tag at CP[%d/%d] = %d",
   790                               this_oop(), index, cache_index, tag_value) );
   791     assert(false, "unexpected constant tag");
   792     break;
   793   }
   795   if (cache_index >= 0) {
   796     // Cache the oop here also.
   797     Handle result_handle(THREAD, result_oop);
   798     oop cplock = this_oop->lock();
   799     ObjectLocker ol(cplock, THREAD, cplock != NULL);  // don't know if we really need this
   800     oop result = this_oop->resolved_references()->obj_at(cache_index);
   801     // Benign race condition:  resolved_references may already be filled in while we were trying to lock.
   802     // The important thing here is that all threads pick up the same result.
   803     // It doesn't matter which racing thread wins, as long as only one
   804     // result is used by all threads, and all future queries.
   805     // That result may be either a resolved constant or a failure exception.
   806     if (result == NULL) {
   807       this_oop->resolved_references()->obj_at_put(cache_index, result_handle());
   808       return result_handle();
   809     } else {
   810       // Return the winning thread's result.  This can be different than
   811       // result_handle() for MethodHandles.
   812       return result;
   813     }
   814   } else {
   815     return result_oop;
   816   }
   817 }
   819 oop ConstantPool::uncached_string_at(int which, TRAPS) {
   820   Symbol* sym = unresolved_string_at(which);
   821   oop str = StringTable::intern(sym, CHECK_(NULL));
   822   assert(java_lang_String::is_instance(str), "must be string");
   823   return str;
   824 }
   827 oop ConstantPool::resolve_bootstrap_specifier_at_impl(constantPoolHandle this_oop, int index, TRAPS) {
   828   assert(this_oop->tag_at(index).is_invoke_dynamic(), "Corrupted constant pool");
   830   Handle bsm;
   831   int argc;
   832   {
   833     // JVM_CONSTANT_InvokeDynamic is an ordered pair of [bootm, name&type], plus optional arguments
   834     // The bootm, being a JVM_CONSTANT_MethodHandle, has its own cache entry.
   835     // It is accompanied by the optional arguments.
   836     int bsm_index = this_oop->invoke_dynamic_bootstrap_method_ref_index_at(index);
   837     oop bsm_oop = this_oop->resolve_possibly_cached_constant_at(bsm_index, CHECK_NULL);
   838     if (!java_lang_invoke_MethodHandle::is_instance(bsm_oop)) {
   839       THROW_MSG_NULL(vmSymbols::java_lang_LinkageError(), "BSM not an MethodHandle");
   840     }
   842     // Extract the optional static arguments.
   843     argc = this_oop->invoke_dynamic_argument_count_at(index);
   844     if (argc == 0)  return bsm_oop;
   846     bsm = Handle(THREAD, bsm_oop);
   847   }
   849   objArrayHandle info;
   850   {
   851     objArrayOop info_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1+argc, CHECK_NULL);
   852     info = objArrayHandle(THREAD, info_oop);
   853   }
   855   info->obj_at_put(0, bsm());
   856   for (int i = 0; i < argc; i++) {
   857     int arg_index = this_oop->invoke_dynamic_argument_index_at(index, i);
   858     oop arg_oop = this_oop->resolve_possibly_cached_constant_at(arg_index, CHECK_NULL);
   859     info->obj_at_put(1+i, arg_oop);
   860   }
   862   return info();
   863 }
   865 oop ConstantPool::string_at_impl(constantPoolHandle this_oop, int which, int obj_index, TRAPS) {
   866   // If the string has already been interned, this entry will be non-null
   867   oop str = this_oop->resolved_references()->obj_at(obj_index);
   868   if (str != NULL) return str;
   870       Symbol* sym = this_oop->unresolved_string_at(which);
   871   str = StringTable::intern(sym, CHECK_(NULL));
   872   this_oop->string_at_put(which, obj_index, str);
   873   assert(java_lang_String::is_instance(str), "must be string");
   874   return str;
   875 }
   878 bool ConstantPool::klass_name_at_matches(instanceKlassHandle k,
   879                                                 int which) {
   880   // Names are interned, so we can compare Symbol*s directly
   881   Symbol* cp_name = klass_name_at(which);
   882   return (cp_name == k->name());
   883 }
   886 // Iterate over symbols and decrement ones which are Symbol*s.
   887 // This is done during GC so do not need to lock constantPool unless we
   888 // have per-thread safepoints.
   889 // Only decrement the UTF8 symbols. Unresolved classes and strings point to
   890 // these symbols but didn't increment the reference count.
   891 void ConstantPool::unreference_symbols() {
   892   for (int index = 1; index < length(); index++) { // Index 0 is unused
   893     constantTag tag = tag_at(index);
   894     if (tag.is_symbol()) {
   895       symbol_at(index)->decrement_refcount();
   896     }
   897   }
   898 }
   901 // Compare this constant pool's entry at index1 to the constant pool
   902 // cp2's entry at index2.
   903 bool ConstantPool::compare_entry_to(int index1, constantPoolHandle cp2,
   904        int index2, TRAPS) {
   906   jbyte t1 = tag_at(index1).value();
   907   jbyte t2 = cp2->tag_at(index2).value();
   910   // JVM_CONSTANT_UnresolvedClassInError is equal to JVM_CONSTANT_UnresolvedClass
   911   // when comparing
   912   if (t1 == JVM_CONSTANT_UnresolvedClassInError) {
   913     t1 = JVM_CONSTANT_UnresolvedClass;
   914   }
   915   if (t2 == JVM_CONSTANT_UnresolvedClassInError) {
   916     t2 = JVM_CONSTANT_UnresolvedClass;
   917   }
   919   if (t1 != t2) {
   920     // Not the same entry type so there is nothing else to check. Note
   921     // that this style of checking will consider resolved/unresolved
   922     // class pairs as different.
   923     // From the ConstantPool* API point of view, this is correct
   924     // behavior. See VM_RedefineClasses::merge_constant_pools() to see how this
   925     // plays out in the context of ConstantPool* merging.
   926     return false;
   927   }
   929   switch (t1) {
   930   case JVM_CONSTANT_Class:
   931   {
   932     Klass* k1 = klass_at(index1, CHECK_false);
   933     Klass* k2 = cp2->klass_at(index2, CHECK_false);
   934     if (k1 == k2) {
   935       return true;
   936     }
   937   } break;
   939   case JVM_CONSTANT_ClassIndex:
   940   {
   941     int recur1 = klass_index_at(index1);
   942     int recur2 = cp2->klass_index_at(index2);
   943     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
   944     if (match) {
   945       return true;
   946     }
   947   } break;
   949   case JVM_CONSTANT_Double:
   950   {
   951     jdouble d1 = double_at(index1);
   952     jdouble d2 = cp2->double_at(index2);
   953     if (d1 == d2) {
   954       return true;
   955     }
   956   } break;
   958   case JVM_CONSTANT_Fieldref:
   959   case JVM_CONSTANT_InterfaceMethodref:
   960   case JVM_CONSTANT_Methodref:
   961   {
   962     int recur1 = uncached_klass_ref_index_at(index1);
   963     int recur2 = cp2->uncached_klass_ref_index_at(index2);
   964     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
   965     if (match) {
   966       recur1 = uncached_name_and_type_ref_index_at(index1);
   967       recur2 = cp2->uncached_name_and_type_ref_index_at(index2);
   968       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
   969       if (match) {
   970         return true;
   971       }
   972     }
   973   } break;
   975   case JVM_CONSTANT_Float:
   976   {
   977     jfloat f1 = float_at(index1);
   978     jfloat f2 = cp2->float_at(index2);
   979     if (f1 == f2) {
   980       return true;
   981     }
   982   } break;
   984   case JVM_CONSTANT_Integer:
   985   {
   986     jint i1 = int_at(index1);
   987     jint i2 = cp2->int_at(index2);
   988     if (i1 == i2) {
   989       return true;
   990     }
   991   } break;
   993   case JVM_CONSTANT_Long:
   994   {
   995     jlong l1 = long_at(index1);
   996     jlong l2 = cp2->long_at(index2);
   997     if (l1 == l2) {
   998       return true;
   999     }
  1000   } break;
  1002   case JVM_CONSTANT_NameAndType:
  1004     int recur1 = name_ref_index_at(index1);
  1005     int recur2 = cp2->name_ref_index_at(index2);
  1006     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
  1007     if (match) {
  1008       recur1 = signature_ref_index_at(index1);
  1009       recur2 = cp2->signature_ref_index_at(index2);
  1010       match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
  1011       if (match) {
  1012         return true;
  1015   } break;
  1017   case JVM_CONSTANT_StringIndex:
  1019     int recur1 = string_index_at(index1);
  1020     int recur2 = cp2->string_index_at(index2);
  1021     bool match = compare_entry_to(recur1, cp2, recur2, CHECK_false);
  1022     if (match) {
  1023       return true;
  1025   } break;
  1027   case JVM_CONSTANT_UnresolvedClass:
  1029     Symbol* k1 = unresolved_klass_at(index1);
  1030     Symbol* k2 = cp2->unresolved_klass_at(index2);
  1031     if (k1 == k2) {
  1032       return true;
  1034   } break;
  1036   case JVM_CONSTANT_MethodType:
  1038     int k1 = method_type_index_at(index1);
  1039     int k2 = cp2->method_type_index_at(index2);
  1040     bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
  1041     if (match) {
  1042       return true;
  1044   } break;
  1046   case JVM_CONSTANT_MethodHandle:
  1048     int k1 = method_handle_ref_kind_at(index1);
  1049     int k2 = cp2->method_handle_ref_kind_at(index2);
  1050     if (k1 == k2) {
  1051       int i1 = method_handle_index_at(index1);
  1052       int i2 = cp2->method_handle_index_at(index2);
  1053       bool match = compare_entry_to(i1, cp2, i2, CHECK_false);
  1054       if (match) {
  1055         return true;
  1058   } break;
  1060   case JVM_CONSTANT_InvokeDynamic:
  1062     int k1 = invoke_dynamic_name_and_type_ref_index_at(index1);
  1063     int k2 = cp2->invoke_dynamic_name_and_type_ref_index_at(index2);
  1064     int i1 = invoke_dynamic_bootstrap_specifier_index(index1);
  1065     int i2 = cp2->invoke_dynamic_bootstrap_specifier_index(index2);
  1066     // separate statements and variables because CHECK_false is used
  1067     bool match_entry = compare_entry_to(k1, cp2, k2, CHECK_false);
  1068     bool match_operand = compare_operand_to(i1, cp2, i2, CHECK_false);
  1069     return (match_entry && match_operand);
  1070   } break;
  1072   case JVM_CONSTANT_String:
  1074     Symbol* s1 = unresolved_string_at(index1);
  1075     Symbol* s2 = cp2->unresolved_string_at(index2);
  1076     if (s1 == s2) {
  1077       return true;
  1079   } break;
  1081   case JVM_CONSTANT_Utf8:
  1083     Symbol* s1 = symbol_at(index1);
  1084     Symbol* s2 = cp2->symbol_at(index2);
  1085     if (s1 == s2) {
  1086       return true;
  1088   } break;
  1090   // Invalid is used as the tag for the second constant pool entry
  1091   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
  1092   // not be seen by itself.
  1093   case JVM_CONSTANT_Invalid: // fall through
  1095   default:
  1096     ShouldNotReachHere();
  1097     break;
  1100   return false;
  1101 } // end compare_entry_to()
  1104 // Resize the operands array with delta_len and delta_size.
  1105 // Used in RedefineClasses for CP merge.
  1106 void ConstantPool::resize_operands(int delta_len, int delta_size, TRAPS) {
  1107   int old_len  = operand_array_length(operands());
  1108   int new_len  = old_len + delta_len;
  1109   int min_len  = (delta_len > 0) ? old_len : new_len;
  1111   int old_size = operands()->length();
  1112   int new_size = old_size + delta_size;
  1113   int min_size = (delta_size > 0) ? old_size : new_size;
  1115   ClassLoaderData* loader_data = pool_holder()->class_loader_data();
  1116   Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, new_size, CHECK);
  1118   // Set index in the resized array for existing elements only
  1119   for (int idx = 0; idx < min_len; idx++) {
  1120     int offset = operand_offset_at(idx);                       // offset in original array
  1121     operand_offset_at_put(new_ops, idx, offset + 2*delta_len); // offset in resized array
  1123   // Copy the bootstrap specifiers only
  1124   Copy::conjoint_memory_atomic(operands()->adr_at(2*old_len),
  1125                                new_ops->adr_at(2*new_len),
  1126                                (min_size - 2*min_len) * sizeof(u2));
  1127   // Explicitly deallocate old operands array.
  1128   // Note, it is not needed for 7u backport.
  1129   if ( operands() != NULL) { // the safety check
  1130     MetadataFactory::free_array<u2>(loader_data, operands());
  1132   set_operands(new_ops);
  1133 } // end resize_operands()
  1136 // Extend the operands array with the length and size of the ext_cp operands.
  1137 // Used in RedefineClasses for CP merge.
  1138 void ConstantPool::extend_operands(constantPoolHandle ext_cp, TRAPS) {
  1139   int delta_len = operand_array_length(ext_cp->operands());
  1140   if (delta_len == 0) {
  1141     return; // nothing to do
  1143   int delta_size = ext_cp->operands()->length();
  1145   assert(delta_len  > 0 && delta_size > 0, "extended operands array must be bigger");
  1147   if (operand_array_length(operands()) == 0) {
  1148     ClassLoaderData* loader_data = pool_holder()->class_loader_data();
  1149     Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, delta_size, CHECK);
  1150     // The first element index defines the offset of second part
  1151     operand_offset_at_put(new_ops, 0, 2*delta_len); // offset in new array
  1152     set_operands(new_ops);
  1153   } else {
  1154     resize_operands(delta_len, delta_size, CHECK);
  1157 } // end extend_operands()
  1160 // Shrink the operands array to a smaller array with new_len length.
  1161 // Used in RedefineClasses for CP merge.
  1162 void ConstantPool::shrink_operands(int new_len, TRAPS) {
  1163   int old_len = operand_array_length(operands());
  1164   if (new_len == old_len) {
  1165     return; // nothing to do
  1167   assert(new_len < old_len, "shrunken operands array must be smaller");
  1169   int free_base  = operand_next_offset_at(new_len - 1);
  1170   int delta_len  = new_len - old_len;
  1171   int delta_size = 2*delta_len + free_base - operands()->length();
  1173   resize_operands(delta_len, delta_size, CHECK);
  1175 } // end shrink_operands()
  1178 void ConstantPool::copy_operands(constantPoolHandle from_cp,
  1179                                  constantPoolHandle to_cp,
  1180                                  TRAPS) {
  1182   int from_oplen = operand_array_length(from_cp->operands());
  1183   int old_oplen  = operand_array_length(to_cp->operands());
  1184   if (from_oplen != 0) {
  1185     ClassLoaderData* loader_data = to_cp->pool_holder()->class_loader_data();
  1186     // append my operands to the target's operands array
  1187     if (old_oplen == 0) {
  1188       // Can't just reuse from_cp's operand list because of deallocation issues
  1189       int len = from_cp->operands()->length();
  1190       Array<u2>* new_ops = MetadataFactory::new_array<u2>(loader_data, len, CHECK);
  1191       Copy::conjoint_memory_atomic(
  1192           from_cp->operands()->adr_at(0), new_ops->adr_at(0), len * sizeof(u2));
  1193       to_cp->set_operands(new_ops);
  1194     } else {
  1195       int old_len  = to_cp->operands()->length();
  1196       int from_len = from_cp->operands()->length();
  1197       int old_off  = old_oplen * sizeof(u2);
  1198       int from_off = from_oplen * sizeof(u2);
  1199       // Use the metaspace for the destination constant pool
  1200       Array<u2>* new_operands = MetadataFactory::new_array<u2>(loader_data, old_len + from_len, CHECK);
  1201       int fillp = 0, len = 0;
  1202       // first part of dest
  1203       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(0),
  1204                                    new_operands->adr_at(fillp),
  1205                                    (len = old_off) * sizeof(u2));
  1206       fillp += len;
  1207       // first part of src
  1208       Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(0),
  1209                                    new_operands->adr_at(fillp),
  1210                                    (len = from_off) * sizeof(u2));
  1211       fillp += len;
  1212       // second part of dest
  1213       Copy::conjoint_memory_atomic(to_cp->operands()->adr_at(old_off),
  1214                                    new_operands->adr_at(fillp),
  1215                                    (len = old_len - old_off) * sizeof(u2));
  1216       fillp += len;
  1217       // second part of src
  1218       Copy::conjoint_memory_atomic(from_cp->operands()->adr_at(from_off),
  1219                                    new_operands->adr_at(fillp),
  1220                                    (len = from_len - from_off) * sizeof(u2));
  1221       fillp += len;
  1222       assert(fillp == new_operands->length(), "");
  1224       // Adjust indexes in the first part of the copied operands array.
  1225       for (int j = 0; j < from_oplen; j++) {
  1226         int offset = operand_offset_at(new_operands, old_oplen + j);
  1227         assert(offset == operand_offset_at(from_cp->operands(), j), "correct copy");
  1228         offset += old_len;  // every new tuple is preceded by old_len extra u2's
  1229         operand_offset_at_put(new_operands, old_oplen + j, offset);
  1232       // replace target operands array with combined array
  1233       to_cp->set_operands(new_operands);
  1236 } // end copy_operands()
  1239 // Copy this constant pool's entries at start_i to end_i (inclusive)
  1240 // to the constant pool to_cp's entries starting at to_i. A total of
  1241 // (end_i - start_i) + 1 entries are copied.
  1242 void ConstantPool::copy_cp_to_impl(constantPoolHandle from_cp, int start_i, int end_i,
  1243        constantPoolHandle to_cp, int to_i, TRAPS) {
  1246   int dest_i = to_i;  // leave original alone for debug purposes
  1248   for (int src_i = start_i; src_i <= end_i; /* see loop bottom */ ) {
  1249     copy_entry_to(from_cp, src_i, to_cp, dest_i, CHECK);
  1251     switch (from_cp->tag_at(src_i).value()) {
  1252     case JVM_CONSTANT_Double:
  1253     case JVM_CONSTANT_Long:
  1254       // double and long take two constant pool entries
  1255       src_i += 2;
  1256       dest_i += 2;
  1257       break;
  1259     default:
  1260       // all others take one constant pool entry
  1261       src_i++;
  1262       dest_i++;
  1263       break;
  1266   copy_operands(from_cp, to_cp, CHECK);
  1268 } // end copy_cp_to_impl()
  1271 // Copy this constant pool's entry at from_i to the constant pool
  1272 // to_cp's entry at to_i.
  1273 void ConstantPool::copy_entry_to(constantPoolHandle from_cp, int from_i,
  1274                                         constantPoolHandle to_cp, int to_i,
  1275                                         TRAPS) {
  1277   int tag = from_cp->tag_at(from_i).value();
  1278   switch (tag) {
  1279   case JVM_CONSTANT_Class:
  1281     Klass* k = from_cp->klass_at(from_i, CHECK);
  1282     to_cp->klass_at_put(to_i, k);
  1283   } break;
  1285   case JVM_CONSTANT_ClassIndex:
  1287     jint ki = from_cp->klass_index_at(from_i);
  1288     to_cp->klass_index_at_put(to_i, ki);
  1289   } break;
  1291   case JVM_CONSTANT_Double:
  1293     jdouble d = from_cp->double_at(from_i);
  1294     to_cp->double_at_put(to_i, d);
  1295     // double takes two constant pool entries so init second entry's tag
  1296     to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
  1297   } break;
  1299   case JVM_CONSTANT_Fieldref:
  1301     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
  1302     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
  1303     to_cp->field_at_put(to_i, class_index, name_and_type_index);
  1304   } break;
  1306   case JVM_CONSTANT_Float:
  1308     jfloat f = from_cp->float_at(from_i);
  1309     to_cp->float_at_put(to_i, f);
  1310   } break;
  1312   case JVM_CONSTANT_Integer:
  1314     jint i = from_cp->int_at(from_i);
  1315     to_cp->int_at_put(to_i, i);
  1316   } break;
  1318   case JVM_CONSTANT_InterfaceMethodref:
  1320     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
  1321     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
  1322     to_cp->interface_method_at_put(to_i, class_index, name_and_type_index);
  1323   } break;
  1325   case JVM_CONSTANT_Long:
  1327     jlong l = from_cp->long_at(from_i);
  1328     to_cp->long_at_put(to_i, l);
  1329     // long takes two constant pool entries so init second entry's tag
  1330     to_cp->tag_at_put(to_i + 1, JVM_CONSTANT_Invalid);
  1331   } break;
  1333   case JVM_CONSTANT_Methodref:
  1335     int class_index = from_cp->uncached_klass_ref_index_at(from_i);
  1336     int name_and_type_index = from_cp->uncached_name_and_type_ref_index_at(from_i);
  1337     to_cp->method_at_put(to_i, class_index, name_and_type_index);
  1338   } break;
  1340   case JVM_CONSTANT_NameAndType:
  1342     int name_ref_index = from_cp->name_ref_index_at(from_i);
  1343     int signature_ref_index = from_cp->signature_ref_index_at(from_i);
  1344     to_cp->name_and_type_at_put(to_i, name_ref_index, signature_ref_index);
  1345   } break;
  1347   case JVM_CONSTANT_StringIndex:
  1349     jint si = from_cp->string_index_at(from_i);
  1350     to_cp->string_index_at_put(to_i, si);
  1351   } break;
  1353   case JVM_CONSTANT_UnresolvedClass:
  1355     // Can be resolved after checking tag, so check the slot first.
  1356     CPSlot entry = from_cp->slot_at(from_i);
  1357     if (entry.is_resolved()) {
  1358       assert(entry.get_klass()->is_klass(), "must be");
  1359       // Already resolved
  1360       to_cp->klass_at_put(to_i, entry.get_klass());
  1361     } else {
  1362       to_cp->unresolved_klass_at_put(to_i, entry.get_symbol());
  1364   } break;
  1366   case JVM_CONSTANT_UnresolvedClassInError:
  1368     Symbol* k = from_cp->unresolved_klass_at(from_i);
  1369     to_cp->unresolved_klass_at_put(to_i, k);
  1370     to_cp->tag_at_put(to_i, JVM_CONSTANT_UnresolvedClassInError);
  1371   } break;
  1374   case JVM_CONSTANT_String:
  1376     Symbol* s = from_cp->unresolved_string_at(from_i);
  1377     to_cp->unresolved_string_at_put(to_i, s);
  1378   } break;
  1380   case JVM_CONSTANT_Utf8:
  1382     Symbol* s = from_cp->symbol_at(from_i);
  1383     // Need to increase refcount, the old one will be thrown away and deferenced
  1384     s->increment_refcount();
  1385     to_cp->symbol_at_put(to_i, s);
  1386   } break;
  1388   case JVM_CONSTANT_MethodType:
  1390     jint k = from_cp->method_type_index_at(from_i);
  1391     to_cp->method_type_index_at_put(to_i, k);
  1392   } break;
  1394   case JVM_CONSTANT_MethodHandle:
  1396     int k1 = from_cp->method_handle_ref_kind_at(from_i);
  1397     int k2 = from_cp->method_handle_index_at(from_i);
  1398     to_cp->method_handle_index_at_put(to_i, k1, k2);
  1399   } break;
  1401   case JVM_CONSTANT_InvokeDynamic:
  1403     int k1 = from_cp->invoke_dynamic_bootstrap_specifier_index(from_i);
  1404     int k2 = from_cp->invoke_dynamic_name_and_type_ref_index_at(from_i);
  1405     k1 += operand_array_length(to_cp->operands());  // to_cp might already have operands
  1406     to_cp->invoke_dynamic_at_put(to_i, k1, k2);
  1407   } break;
  1409   // Invalid is used as the tag for the second constant pool entry
  1410   // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should
  1411   // not be seen by itself.
  1412   case JVM_CONSTANT_Invalid: // fall through
  1414   default:
  1416     ShouldNotReachHere();
  1417   } break;
  1419 } // end copy_entry_to()
  1422 // Search constant pool search_cp for an entry that matches this
  1423 // constant pool's entry at pattern_i. Returns the index of a
  1424 // matching entry or zero (0) if there is no matching entry.
  1425 int ConstantPool::find_matching_entry(int pattern_i,
  1426       constantPoolHandle search_cp, TRAPS) {
  1428   // index zero (0) is not used
  1429   for (int i = 1; i < search_cp->length(); i++) {
  1430     bool found = compare_entry_to(pattern_i, search_cp, i, CHECK_0);
  1431     if (found) {
  1432       return i;
  1436   return 0;  // entry not found; return unused index zero (0)
  1437 } // end find_matching_entry()
  1440 // Compare this constant pool's bootstrap specifier at idx1 to the constant pool
  1441 // cp2's bootstrap specifier at idx2.
  1442 bool ConstantPool::compare_operand_to(int idx1, constantPoolHandle cp2, int idx2, TRAPS) {
  1443   int k1 = operand_bootstrap_method_ref_index_at(idx1);
  1444   int k2 = cp2->operand_bootstrap_method_ref_index_at(idx2);
  1445   bool match = compare_entry_to(k1, cp2, k2, CHECK_false);
  1447   if (!match) {
  1448     return false;
  1450   int argc = operand_argument_count_at(idx1);
  1451   if (argc == cp2->operand_argument_count_at(idx2)) {
  1452     for (int j = 0; j < argc; j++) {
  1453       k1 = operand_argument_index_at(idx1, j);
  1454       k2 = cp2->operand_argument_index_at(idx2, j);
  1455       match = compare_entry_to(k1, cp2, k2, CHECK_false);
  1456       if (!match) {
  1457         return false;
  1460     return true;           // got through loop; all elements equal
  1462   return false;
  1463 } // end compare_operand_to()
  1465 // Search constant pool search_cp for a bootstrap specifier that matches
  1466 // this constant pool's bootstrap specifier at pattern_i index.
  1467 // Return the index of a matching bootstrap specifier or (-1) if there is no match.
  1468 int ConstantPool::find_matching_operand(int pattern_i,
  1469                     constantPoolHandle search_cp, int search_len, TRAPS) {
  1470   for (int i = 0; i < search_len; i++) {
  1471     bool found = compare_operand_to(pattern_i, search_cp, i, CHECK_(-1));
  1472     if (found) {
  1473       return i;
  1476   return -1;  // bootstrap specifier not found; return unused index (-1)
  1477 } // end find_matching_operand()
  1480 #ifndef PRODUCT
  1482 const char* ConstantPool::printable_name_at(int which) {
  1484   constantTag tag = tag_at(which);
  1486   if (tag.is_string()) {
  1487     return string_at_noresolve(which);
  1488   } else if (tag.is_klass() || tag.is_unresolved_klass()) {
  1489     return klass_name_at(which)->as_C_string();
  1490   } else if (tag.is_symbol()) {
  1491     return symbol_at(which)->as_C_string();
  1493   return "";
  1496 #endif // PRODUCT
  1499 // JVMTI GetConstantPool support
  1501 // For debugging of constant pool
  1502 const bool debug_cpool = false;
  1504 #define DBG(code) do { if (debug_cpool) { (code); } } while(0)
  1506 static void print_cpool_bytes(jint cnt, u1 *bytes) {
  1507   const char* WARN_MSG = "Must not be such entry!";
  1508   jint size = 0;
  1509   u2   idx1, idx2;
  1511   for (jint idx = 1; idx < cnt; idx++) {
  1512     jint ent_size = 0;
  1513     u1   tag  = *bytes++;
  1514     size++;                       // count tag
  1516     printf("const #%03d, tag: %02d ", idx, tag);
  1517     switch(tag) {
  1518       case JVM_CONSTANT_Invalid: {
  1519         printf("Invalid");
  1520         break;
  1522       case JVM_CONSTANT_Unicode: {
  1523         printf("Unicode      %s", WARN_MSG);
  1524         break;
  1526       case JVM_CONSTANT_Utf8: {
  1527         u2 len = Bytes::get_Java_u2(bytes);
  1528         char str[128];
  1529         if (len > 127) {
  1530            len = 127;
  1532         strncpy(str, (char *) (bytes+2), len);
  1533         str[len] = '\0';
  1534         printf("Utf8          \"%s\"", str);
  1535         ent_size = 2 + len;
  1536         break;
  1538       case JVM_CONSTANT_Integer: {
  1539         u4 val = Bytes::get_Java_u4(bytes);
  1540         printf("int          %d", *(int *) &val);
  1541         ent_size = 4;
  1542         break;
  1544       case JVM_CONSTANT_Float: {
  1545         u4 val = Bytes::get_Java_u4(bytes);
  1546         printf("float        %5.3ff", *(float *) &val);
  1547         ent_size = 4;
  1548         break;
  1550       case JVM_CONSTANT_Long: {
  1551         u8 val = Bytes::get_Java_u8(bytes);
  1552         printf("long         "INT64_FORMAT, (int64_t) *(jlong *) &val);
  1553         ent_size = 8;
  1554         idx++; // Long takes two cpool slots
  1555         break;
  1557       case JVM_CONSTANT_Double: {
  1558         u8 val = Bytes::get_Java_u8(bytes);
  1559         printf("double       %5.3fd", *(jdouble *)&val);
  1560         ent_size = 8;
  1561         idx++; // Double takes two cpool slots
  1562         break;
  1564       case JVM_CONSTANT_Class: {
  1565         idx1 = Bytes::get_Java_u2(bytes);
  1566         printf("class        #%03d", idx1);
  1567         ent_size = 2;
  1568         break;
  1570       case JVM_CONSTANT_String: {
  1571         idx1 = Bytes::get_Java_u2(bytes);
  1572         printf("String       #%03d", idx1);
  1573         ent_size = 2;
  1574         break;
  1576       case JVM_CONSTANT_Fieldref: {
  1577         idx1 = Bytes::get_Java_u2(bytes);
  1578         idx2 = Bytes::get_Java_u2(bytes+2);
  1579         printf("Field        #%03d, #%03d", (int) idx1, (int) idx2);
  1580         ent_size = 4;
  1581         break;
  1583       case JVM_CONSTANT_Methodref: {
  1584         idx1 = Bytes::get_Java_u2(bytes);
  1585         idx2 = Bytes::get_Java_u2(bytes+2);
  1586         printf("Method       #%03d, #%03d", idx1, idx2);
  1587         ent_size = 4;
  1588         break;
  1590       case JVM_CONSTANT_InterfaceMethodref: {
  1591         idx1 = Bytes::get_Java_u2(bytes);
  1592         idx2 = Bytes::get_Java_u2(bytes+2);
  1593         printf("InterfMethod #%03d, #%03d", idx1, idx2);
  1594         ent_size = 4;
  1595         break;
  1597       case JVM_CONSTANT_NameAndType: {
  1598         idx1 = Bytes::get_Java_u2(bytes);
  1599         idx2 = Bytes::get_Java_u2(bytes+2);
  1600         printf("NameAndType  #%03d, #%03d", idx1, idx2);
  1601         ent_size = 4;
  1602         break;
  1604       case JVM_CONSTANT_ClassIndex: {
  1605         printf("ClassIndex  %s", WARN_MSG);
  1606         break;
  1608       case JVM_CONSTANT_UnresolvedClass: {
  1609         printf("UnresolvedClass: %s", WARN_MSG);
  1610         break;
  1612       case JVM_CONSTANT_UnresolvedClassInError: {
  1613         printf("UnresolvedClassInErr: %s", WARN_MSG);
  1614         break;
  1616       case JVM_CONSTANT_StringIndex: {
  1617         printf("StringIndex: %s", WARN_MSG);
  1618         break;
  1621     printf(";\n");
  1622     bytes += ent_size;
  1623     size  += ent_size;
  1625   printf("Cpool size: %d\n", size);
  1626   fflush(0);
  1627   return;
  1628 } /* end print_cpool_bytes */
  1631 // Returns size of constant pool entry.
  1632 jint ConstantPool::cpool_entry_size(jint idx) {
  1633   switch(tag_at(idx).value()) {
  1634     case JVM_CONSTANT_Invalid:
  1635     case JVM_CONSTANT_Unicode:
  1636       return 1;
  1638     case JVM_CONSTANT_Utf8:
  1639       return 3 + symbol_at(idx)->utf8_length();
  1641     case JVM_CONSTANT_Class:
  1642     case JVM_CONSTANT_String:
  1643     case JVM_CONSTANT_ClassIndex:
  1644     case JVM_CONSTANT_UnresolvedClass:
  1645     case JVM_CONSTANT_UnresolvedClassInError:
  1646     case JVM_CONSTANT_StringIndex:
  1647     case JVM_CONSTANT_MethodType:
  1648       return 3;
  1650     case JVM_CONSTANT_MethodHandle:
  1651       return 4; //tag, ref_kind, ref_index
  1653     case JVM_CONSTANT_Integer:
  1654     case JVM_CONSTANT_Float:
  1655     case JVM_CONSTANT_Fieldref:
  1656     case JVM_CONSTANT_Methodref:
  1657     case JVM_CONSTANT_InterfaceMethodref:
  1658     case JVM_CONSTANT_NameAndType:
  1659       return 5;
  1661     case JVM_CONSTANT_InvokeDynamic:
  1662       // u1 tag, u2 bsm, u2 nt
  1663       return 5;
  1665     case JVM_CONSTANT_Long:
  1666     case JVM_CONSTANT_Double:
  1667       return 9;
  1669   assert(false, "cpool_entry_size: Invalid constant pool entry tag");
  1670   return 1;
  1671 } /* end cpool_entry_size */
  1674 // SymbolHashMap is used to find a constant pool index from a string.
  1675 // This function fills in SymbolHashMaps, one for utf8s and one for
  1676 // class names, returns size of the cpool raw bytes.
  1677 jint ConstantPool::hash_entries_to(SymbolHashMap *symmap,
  1678                                           SymbolHashMap *classmap) {
  1679   jint size = 0;
  1681   for (u2 idx = 1; idx < length(); idx++) {
  1682     u2 tag = tag_at(idx).value();
  1683     size += cpool_entry_size(idx);
  1685     switch(tag) {
  1686       case JVM_CONSTANT_Utf8: {
  1687         Symbol* sym = symbol_at(idx);
  1688         symmap->add_entry(sym, idx);
  1689         DBG(printf("adding symbol entry %s = %d\n", sym->as_utf8(), idx));
  1690         break;
  1692       case JVM_CONSTANT_Class:
  1693       case JVM_CONSTANT_UnresolvedClass:
  1694       case JVM_CONSTANT_UnresolvedClassInError: {
  1695         Symbol* sym = klass_name_at(idx);
  1696         classmap->add_entry(sym, idx);
  1697         DBG(printf("adding class entry %s = %d\n", sym->as_utf8(), idx));
  1698         break;
  1700       case JVM_CONSTANT_Long:
  1701       case JVM_CONSTANT_Double: {
  1702         idx++; // Both Long and Double take two cpool slots
  1703         break;
  1707   return size;
  1708 } /* end hash_utf8_entries_to */
  1711 // Copy cpool bytes.
  1712 // Returns:
  1713 //    0, in case of OutOfMemoryError
  1714 //   -1, in case of internal error
  1715 //  > 0, count of the raw cpool bytes that have been copied
  1716 int ConstantPool::copy_cpool_bytes(int cpool_size,
  1717                                           SymbolHashMap* tbl,
  1718                                           unsigned char *bytes) {
  1719   u2   idx1, idx2;
  1720   jint size  = 0;
  1721   jint cnt   = length();
  1722   unsigned char *start_bytes = bytes;
  1724   for (jint idx = 1; idx < cnt; idx++) {
  1725     u1   tag      = tag_at(idx).value();
  1726     jint ent_size = cpool_entry_size(idx);
  1728     assert(size + ent_size <= cpool_size, "Size mismatch");
  1730     *bytes = tag;
  1731     DBG(printf("#%03hd tag=%03hd, ", idx, tag));
  1732     switch(tag) {
  1733       case JVM_CONSTANT_Invalid: {
  1734         DBG(printf("JVM_CONSTANT_Invalid"));
  1735         break;
  1737       case JVM_CONSTANT_Unicode: {
  1738         assert(false, "Wrong constant pool tag: JVM_CONSTANT_Unicode");
  1739         DBG(printf("JVM_CONSTANT_Unicode"));
  1740         break;
  1742       case JVM_CONSTANT_Utf8: {
  1743         Symbol* sym = symbol_at(idx);
  1744         char*     str = sym->as_utf8();
  1745         // Warning! It's crashing on x86 with len = sym->utf8_length()
  1746         int       len = (int) strlen(str);
  1747         Bytes::put_Java_u2((address) (bytes+1), (u2) len);
  1748         for (int i = 0; i < len; i++) {
  1749             bytes[3+i] = (u1) str[i];
  1751         DBG(printf("JVM_CONSTANT_Utf8: %s ", str));
  1752         break;
  1754       case JVM_CONSTANT_Integer: {
  1755         jint val = int_at(idx);
  1756         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
  1757         break;
  1759       case JVM_CONSTANT_Float: {
  1760         jfloat val = float_at(idx);
  1761         Bytes::put_Java_u4((address) (bytes+1), *(u4*)&val);
  1762         break;
  1764       case JVM_CONSTANT_Long: {
  1765         jlong val = long_at(idx);
  1766         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
  1767         idx++;             // Long takes two cpool slots
  1768         break;
  1770       case JVM_CONSTANT_Double: {
  1771         jdouble val = double_at(idx);
  1772         Bytes::put_Java_u8((address) (bytes+1), *(u8*)&val);
  1773         idx++;             // Double takes two cpool slots
  1774         break;
  1776       case JVM_CONSTANT_Class:
  1777       case JVM_CONSTANT_UnresolvedClass:
  1778       case JVM_CONSTANT_UnresolvedClassInError: {
  1779         *bytes = JVM_CONSTANT_Class;
  1780         Symbol* sym = klass_name_at(idx);
  1781         idx1 = tbl->symbol_to_value(sym);
  1782         assert(idx1 != 0, "Have not found a hashtable entry");
  1783         Bytes::put_Java_u2((address) (bytes+1), idx1);
  1784         DBG(printf("JVM_CONSTANT_Class: idx=#%03hd, %s", idx1, sym->as_utf8()));
  1785         break;
  1787       case JVM_CONSTANT_String: {
  1788         *bytes = JVM_CONSTANT_String;
  1789         Symbol* sym = unresolved_string_at(idx);
  1790         idx1 = tbl->symbol_to_value(sym);
  1791         assert(idx1 != 0, "Have not found a hashtable entry");
  1792         Bytes::put_Java_u2((address) (bytes+1), idx1);
  1793         DBG(printf("JVM_CONSTANT_String: idx=#%03hd, %s", idx1, sym->as_utf8()));
  1794         break;
  1796       case JVM_CONSTANT_Fieldref:
  1797       case JVM_CONSTANT_Methodref:
  1798       case JVM_CONSTANT_InterfaceMethodref: {
  1799         idx1 = uncached_klass_ref_index_at(idx);
  1800         idx2 = uncached_name_and_type_ref_index_at(idx);
  1801         Bytes::put_Java_u2((address) (bytes+1), idx1);
  1802         Bytes::put_Java_u2((address) (bytes+3), idx2);
  1803         DBG(printf("JVM_CONSTANT_Methodref: %hd %hd", idx1, idx2));
  1804         break;
  1806       case JVM_CONSTANT_NameAndType: {
  1807         idx1 = name_ref_index_at(idx);
  1808         idx2 = signature_ref_index_at(idx);
  1809         Bytes::put_Java_u2((address) (bytes+1), idx1);
  1810         Bytes::put_Java_u2((address) (bytes+3), idx2);
  1811         DBG(printf("JVM_CONSTANT_NameAndType: %hd %hd", idx1, idx2));
  1812         break;
  1814       case JVM_CONSTANT_ClassIndex: {
  1815         *bytes = JVM_CONSTANT_Class;
  1816         idx1 = klass_index_at(idx);
  1817         Bytes::put_Java_u2((address) (bytes+1), idx1);
  1818         DBG(printf("JVM_CONSTANT_ClassIndex: %hd", idx1));
  1819         break;
  1821       case JVM_CONSTANT_StringIndex: {
  1822         *bytes = JVM_CONSTANT_String;
  1823         idx1 = string_index_at(idx);
  1824         Bytes::put_Java_u2((address) (bytes+1), idx1);
  1825         DBG(printf("JVM_CONSTANT_StringIndex: %hd", idx1));
  1826         break;
  1828       case JVM_CONSTANT_MethodHandle:
  1829       case JVM_CONSTANT_MethodHandleInError: {
  1830         *bytes = JVM_CONSTANT_MethodHandle;
  1831         int kind = method_handle_ref_kind_at(idx);
  1832         idx1 = method_handle_index_at(idx);
  1833         *(bytes+1) = (unsigned char) kind;
  1834         Bytes::put_Java_u2((address) (bytes+2), idx1);
  1835         DBG(printf("JVM_CONSTANT_MethodHandle: %d %hd", kind, idx1));
  1836         break;
  1838       case JVM_CONSTANT_MethodType:
  1839       case JVM_CONSTANT_MethodTypeInError: {
  1840         *bytes = JVM_CONSTANT_MethodType;
  1841         idx1 = method_type_index_at(idx);
  1842         Bytes::put_Java_u2((address) (bytes+1), idx1);
  1843         DBG(printf("JVM_CONSTANT_MethodType: %hd", idx1));
  1844         break;
  1846       case JVM_CONSTANT_InvokeDynamic: {
  1847         *bytes = tag;
  1848         idx1 = extract_low_short_from_int(*int_at_addr(idx));
  1849         idx2 = extract_high_short_from_int(*int_at_addr(idx));
  1850         assert(idx2 == invoke_dynamic_name_and_type_ref_index_at(idx), "correct half of u4");
  1851         Bytes::put_Java_u2((address) (bytes+1), idx1);
  1852         Bytes::put_Java_u2((address) (bytes+3), idx2);
  1853         DBG(printf("JVM_CONSTANT_InvokeDynamic: %hd %hd", idx1, idx2));
  1854         break;
  1857     DBG(printf("\n"));
  1858     bytes += ent_size;
  1859     size  += ent_size;
  1861   assert(size == cpool_size, "Size mismatch");
  1863   // Keep temorarily for debugging until it's stable.
  1864   DBG(print_cpool_bytes(cnt, start_bytes));
  1865   return (int)(bytes - start_bytes);
  1866 } /* end copy_cpool_bytes */
  1868 #undef DBG
  1871 void ConstantPool::set_on_stack(const bool value) {
  1872   if (value) {
  1873     _flags |= _on_stack;
  1874   } else {
  1875     _flags &= ~_on_stack;
  1877   if (value) MetadataOnStackMark::record(this);
  1880 // JSR 292 support for patching constant pool oops after the class is linked and
  1881 // the oop array for resolved references are created.
  1882 // We can't do this during classfile parsing, which is how the other indexes are
  1883 // patched.  The other patches are applied early for some error checking
  1884 // so only defer the pseudo_strings.
  1885 void ConstantPool::patch_resolved_references(
  1886                                             GrowableArray<Handle>* cp_patches) {
  1887   assert(EnableInvokeDynamic, "");
  1888   for (int index = 1; index < cp_patches->length(); index++) { // Index 0 is unused
  1889     Handle patch = cp_patches->at(index);
  1890     if (patch.not_null()) {
  1891       assert (tag_at(index).is_string(), "should only be string left");
  1892       // Patching a string means pre-resolving it.
  1893       // The spelling in the constant pool is ignored.
  1894       // The constant reference may be any object whatever.
  1895       // If it is not a real interned string, the constant is referred
  1896       // to as a "pseudo-string", and must be presented to the CP
  1897       // explicitly, because it may require scavenging.
  1898       int obj_index = cp_to_object_index(index);
  1899       pseudo_string_at_put(index, obj_index, patch());
  1900       DEBUG_ONLY(cp_patches->at_put(index, Handle());)
  1903 #ifdef ASSERT
  1904   // Ensure that all the patches have been used.
  1905   for (int index = 0; index < cp_patches->length(); index++) {
  1906     assert(cp_patches->at(index).is_null(),
  1907            err_msg("Unused constant pool patch at %d in class file %s",
  1908                    index,
  1909                    pool_holder()->external_name()));
  1911 #endif // ASSERT
  1914 #ifndef PRODUCT
  1916 // CompileTheWorld support. Preload all classes loaded references in the passed in constantpool
  1917 void ConstantPool::preload_and_initialize_all_classes(ConstantPool* obj, TRAPS) {
  1918   guarantee(obj->is_constantPool(), "object must be constant pool");
  1919   constantPoolHandle cp(THREAD, (ConstantPool*)obj);
  1920   guarantee(cp->pool_holder() != NULL, "must be fully loaded");
  1922   for (int i = 0; i< cp->length();  i++) {
  1923     if (cp->tag_at(i).is_unresolved_klass()) {
  1924       // This will force loading of the class
  1925       Klass* klass = cp->klass_at(i, CHECK);
  1926       if (klass->oop_is_instance()) {
  1927         // Force initialization of class
  1928         InstanceKlass::cast(klass)->initialize(CHECK);
  1934 #endif
  1937 // Printing
  1939 void ConstantPool::print_on(outputStream* st) const {
  1940   EXCEPTION_MARK;
  1941   assert(is_constantPool(), "must be constantPool");
  1942   st->print_cr(internal_name());
  1943   if (flags() != 0) {
  1944     st->print(" - flags: 0x%x", flags());
  1945     if (has_preresolution()) st->print(" has_preresolution");
  1946     if (on_stack()) st->print(" on_stack");
  1947     st->cr();
  1949   if (pool_holder() != NULL) {
  1950     st->print_cr(" - holder: " INTPTR_FORMAT, pool_holder());
  1952   st->print_cr(" - cache: " INTPTR_FORMAT, cache());
  1953   st->print_cr(" - resolved_references: " INTPTR_FORMAT, resolved_references());
  1954   st->print_cr(" - reference_map: " INTPTR_FORMAT, reference_map());
  1956   for (int index = 1; index < length(); index++) {      // Index 0 is unused
  1957     ((ConstantPool*)this)->print_entry_on(index, st);
  1958     switch (tag_at(index).value()) {
  1959       case JVM_CONSTANT_Long :
  1960       case JVM_CONSTANT_Double :
  1961         index++;   // Skip entry following eigth-byte constant
  1965   st->cr();
  1968 // Print one constant pool entry
  1969 void ConstantPool::print_entry_on(const int index, outputStream* st) {
  1970   EXCEPTION_MARK;
  1971   st->print(" - %3d : ", index);
  1972   tag_at(index).print_on(st);
  1973   st->print(" : ");
  1974   switch (tag_at(index).value()) {
  1975     case JVM_CONSTANT_Class :
  1976       { Klass* k = klass_at(index, CATCH);
  1977         guarantee(k != NULL, "need klass");
  1978         k->print_value_on(st);
  1979         st->print(" {0x%lx}", (address)k);
  1981       break;
  1982     case JVM_CONSTANT_Fieldref :
  1983     case JVM_CONSTANT_Methodref :
  1984     case JVM_CONSTANT_InterfaceMethodref :
  1985       st->print("klass_index=%d", uncached_klass_ref_index_at(index));
  1986       st->print(" name_and_type_index=%d", uncached_name_and_type_ref_index_at(index));
  1987       break;
  1988     case JVM_CONSTANT_String :
  1989       if (is_pseudo_string_at(index)) {
  1990         oop anObj = pseudo_string_at(index);
  1991         anObj->print_value_on(st);
  1992         st->print(" {0x%lx}", (address)anObj);
  1993       } else {
  1994         unresolved_string_at(index)->print_value_on(st);
  1996       break;
  1997     case JVM_CONSTANT_Integer :
  1998       st->print("%d", int_at(index));
  1999       break;
  2000     case JVM_CONSTANT_Float :
  2001       st->print("%f", float_at(index));
  2002       break;
  2003     case JVM_CONSTANT_Long :
  2004       st->print_jlong(long_at(index));
  2005       break;
  2006     case JVM_CONSTANT_Double :
  2007       st->print("%lf", double_at(index));
  2008       break;
  2009     case JVM_CONSTANT_NameAndType :
  2010       st->print("name_index=%d", name_ref_index_at(index));
  2011       st->print(" signature_index=%d", signature_ref_index_at(index));
  2012       break;
  2013     case JVM_CONSTANT_Utf8 :
  2014       symbol_at(index)->print_value_on(st);
  2015       break;
  2016     case JVM_CONSTANT_UnresolvedClass :               // fall-through
  2017     case JVM_CONSTANT_UnresolvedClassInError: {
  2018       // unresolved_klass_at requires lock or safe world.
  2019       CPSlot entry = slot_at(index);
  2020       if (entry.is_resolved()) {
  2021         entry.get_klass()->print_value_on(st);
  2022       } else {
  2023         entry.get_symbol()->print_value_on(st);
  2026       break;
  2027     case JVM_CONSTANT_MethodHandle :
  2028     case JVM_CONSTANT_MethodHandleInError :
  2029       st->print("ref_kind=%d", method_handle_ref_kind_at(index));
  2030       st->print(" ref_index=%d", method_handle_index_at(index));
  2031       break;
  2032     case JVM_CONSTANT_MethodType :
  2033     case JVM_CONSTANT_MethodTypeInError :
  2034       st->print("signature_index=%d", method_type_index_at(index));
  2035       break;
  2036     case JVM_CONSTANT_InvokeDynamic :
  2038         st->print("bootstrap_method_index=%d", invoke_dynamic_bootstrap_method_ref_index_at(index));
  2039         st->print(" name_and_type_index=%d", invoke_dynamic_name_and_type_ref_index_at(index));
  2040         int argc = invoke_dynamic_argument_count_at(index);
  2041         if (argc > 0) {
  2042           for (int arg_i = 0; arg_i < argc; arg_i++) {
  2043             int arg = invoke_dynamic_argument_index_at(index, arg_i);
  2044             st->print((arg_i == 0 ? " arguments={%d" : ", %d"), arg);
  2046           st->print("}");
  2049       break;
  2050     default:
  2051       ShouldNotReachHere();
  2052       break;
  2054   st->cr();
  2057 void ConstantPool::print_value_on(outputStream* st) const {
  2058   assert(is_constantPool(), "must be constantPool");
  2059   st->print("constant pool [%d]", length());
  2060   if (has_preresolution()) st->print("/preresolution");
  2061   if (operands() != NULL)  st->print("/operands[%d]", operands()->length());
  2062   print_address_on(st);
  2063   st->print(" for ");
  2064   pool_holder()->print_value_on(st);
  2065   if (pool_holder() != NULL) {
  2066     bool extra = (pool_holder()->constants() != this);
  2067     if (extra)  st->print(" (extra)");
  2069   if (cache() != NULL) {
  2070     st->print(" cache=" PTR_FORMAT, cache());
  2074 #if INCLUDE_SERVICES
  2075 // Size Statistics
  2076 void ConstantPool::collect_statistics(KlassSizeStats *sz) const {
  2077   sz->_cp_all_bytes += (sz->_cp_bytes          = sz->count(this));
  2078   sz->_cp_all_bytes += (sz->_cp_tags_bytes     = sz->count_array(tags()));
  2079   sz->_cp_all_bytes += (sz->_cp_cache_bytes    = sz->count(cache()));
  2080   sz->_cp_all_bytes += (sz->_cp_operands_bytes = sz->count_array(operands()));
  2081   sz->_cp_all_bytes += (sz->_cp_refmap_bytes   = sz->count_array(reference_map()));
  2083   sz->_ro_bytes += sz->_cp_operands_bytes + sz->_cp_tags_bytes +
  2084                    sz->_cp_refmap_bytes;
  2085   sz->_rw_bytes += sz->_cp_bytes + sz->_cp_cache_bytes;
  2087 #endif // INCLUDE_SERVICES
  2089 // Verification
  2091 void ConstantPool::verify_on(outputStream* st) {
  2092   guarantee(is_constantPool(), "object must be constant pool");
  2093   for (int i = 0; i< length();  i++) {
  2094     constantTag tag = tag_at(i);
  2095     CPSlot entry = slot_at(i);
  2096     if (tag.is_klass()) {
  2097       if (entry.is_resolved()) {
  2098         guarantee(entry.get_klass()->is_klass(),    "should be klass");
  2100     } else if (tag.is_unresolved_klass()) {
  2101       if (entry.is_resolved()) {
  2102         guarantee(entry.get_klass()->is_klass(),    "should be klass");
  2104     } else if (tag.is_symbol()) {
  2105       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
  2106     } else if (tag.is_string()) {
  2107       guarantee(entry.get_symbol()->refcount() != 0, "should have nonzero reference count");
  2110   if (cache() != NULL) {
  2111     // Note: cache() can be NULL before a class is completely setup or
  2112     // in temporary constant pools used during constant pool merging
  2113     guarantee(cache()->is_constantPoolCache(), "should be constant pool cache");
  2115   if (pool_holder() != NULL) {
  2116     // Note: pool_holder() can be NULL in temporary constant pools
  2117     // used during constant pool merging
  2118     guarantee(pool_holder()->is_klass(),    "should be klass");
  2123 void SymbolHashMap::add_entry(Symbol* sym, u2 value) {
  2124   char *str = sym->as_utf8();
  2125   unsigned int hash = compute_hash(str, sym->utf8_length());
  2126   unsigned int index = hash % table_size();
  2128   // check if already in map
  2129   // we prefer the first entry since it is more likely to be what was used in
  2130   // the class file
  2131   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
  2132     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
  2133     if (en->hash() == hash && en->symbol() == sym) {
  2134         return;  // already there
  2138   SymbolHashMapEntry* entry = new SymbolHashMapEntry(hash, sym, value);
  2139   entry->set_next(bucket(index));
  2140   _buckets[index].set_entry(entry);
  2141   assert(entry->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
  2144 SymbolHashMapEntry* SymbolHashMap::find_entry(Symbol* sym) {
  2145   assert(sym != NULL, "SymbolHashMap::find_entry - symbol is NULL");
  2146   char *str = sym->as_utf8();
  2147   int   len = sym->utf8_length();
  2148   unsigned int hash = SymbolHashMap::compute_hash(str, len);
  2149   unsigned int index = hash % table_size();
  2150   for (SymbolHashMapEntry *en = bucket(index); en != NULL; en = en->next()) {
  2151     assert(en->symbol() != NULL, "SymbolHashMapEntry symbol is NULL");
  2152     if (en->hash() == hash && en->symbol() == sym) {
  2153       return en;
  2156   return NULL;

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