src/share/vm/oops/instanceKlass.cpp

Tue, 08 Jan 2013 11:39:53 -0800

author
zgu
date
Tue, 08 Jan 2013 11:39:53 -0800
changeset 4401
37a3e8b7a1e9
parent 4400
ecd24264898b
parent 4395
cc6a617fffd2
child 4453
ed6154d7d259
permissions
-rw-r--r--

Merge

     1 /*
     2  * Copyright (c) 1997, 2012, 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/javaClasses.hpp"
    27 #include "classfile/systemDictionary.hpp"
    28 #include "classfile/verifier.hpp"
    29 #include "classfile/vmSymbols.hpp"
    30 #include "compiler/compileBroker.hpp"
    31 #include "gc_implementation/shared/markSweep.inline.hpp"
    32 #include "gc_interface/collectedHeap.inline.hpp"
    33 #include "interpreter/oopMapCache.hpp"
    34 #include "interpreter/rewriter.hpp"
    35 #include "jvmtifiles/jvmti.h"
    36 #include "memory/genOopClosures.inline.hpp"
    37 #include "memory/metadataFactory.hpp"
    38 #include "memory/oopFactory.hpp"
    39 #include "oops/fieldStreams.hpp"
    40 #include "oops/instanceClassLoaderKlass.hpp"
    41 #include "oops/instanceKlass.hpp"
    42 #include "oops/instanceMirrorKlass.hpp"
    43 #include "oops/instanceOop.hpp"
    44 #include "oops/klass.inline.hpp"
    45 #include "oops/method.hpp"
    46 #include "oops/oop.inline.hpp"
    47 #include "oops/symbol.hpp"
    48 #include "prims/jvmtiExport.hpp"
    49 #include "prims/jvmtiRedefineClassesTrace.hpp"
    50 #include "prims/methodComparator.hpp"
    51 #include "runtime/fieldDescriptor.hpp"
    52 #include "runtime/handles.inline.hpp"
    53 #include "runtime/javaCalls.hpp"
    54 #include "runtime/mutexLocker.hpp"
    55 #include "runtime/thread.inline.hpp"
    56 #include "services/threadService.hpp"
    57 #include "utilities/dtrace.hpp"
    58 #ifndef SERIALGC
    59 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp"
    60 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
    61 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
    62 #include "gc_implementation/g1/g1RemSet.inline.hpp"
    63 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
    64 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
    65 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp"
    66 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
    67 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
    68 #include "oops/oop.pcgc.inline.hpp"
    69 #endif
    70 #ifdef COMPILER1
    71 #include "c1/c1_Compiler.hpp"
    72 #endif
    74 #ifdef DTRACE_ENABLED
    76 #ifndef USDT2
    78 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
    79   char*, intptr_t, oop, intptr_t);
    80 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
    81   char*, intptr_t, oop, intptr_t, int);
    82 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
    83   char*, intptr_t, oop, intptr_t, int);
    84 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
    85   char*, intptr_t, oop, intptr_t, int);
    86 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
    87   char*, intptr_t, oop, intptr_t, int);
    88 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
    89   char*, intptr_t, oop, intptr_t, int);
    90 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
    91   char*, intptr_t, oop, intptr_t, int);
    92 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
    93   char*, intptr_t, oop, intptr_t, int);
    95 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
    96   {                                                              \
    97     char* data = NULL;                                           \
    98     int len = 0;                                                 \
    99     Symbol* name = (clss)->name();                               \
   100     if (name != NULL) {                                          \
   101       data = (char*)name->bytes();                               \
   102       len = name->utf8_length();                                 \
   103     }                                                            \
   104     HS_DTRACE_PROBE4(hotspot, class__initialization__##type,     \
   105       data, len, (clss)->class_loader(), thread_type);           \
   106   }
   108 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
   109   {                                                              \
   110     char* data = NULL;                                           \
   111     int len = 0;                                                 \
   112     Symbol* name = (clss)->name();                               \
   113     if (name != NULL) {                                          \
   114       data = (char*)name->bytes();                               \
   115       len = name->utf8_length();                                 \
   116     }                                                            \
   117     HS_DTRACE_PROBE5(hotspot, class__initialization__##type,     \
   118       data, len, (clss)->class_loader(), thread_type, wait);     \
   119   }
   120 #else /* USDT2 */
   122 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
   123 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
   124 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
   125 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
   126 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
   127 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
   128 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
   129 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
   130 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
   131   {                                                              \
   132     char* data = NULL;                                           \
   133     int len = 0;                                                 \
   134     Symbol* name = (clss)->name();                               \
   135     if (name != NULL) {                                          \
   136       data = (char*)name->bytes();                               \
   137       len = name->utf8_length();                                 \
   138     }                                                            \
   139     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
   140       data, len, (clss)->class_loader(), thread_type);           \
   141   }
   143 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
   144   {                                                              \
   145     char* data = NULL;                                           \
   146     int len = 0;                                                 \
   147     Symbol* name = (clss)->name();                               \
   148     if (name != NULL) {                                          \
   149       data = (char*)name->bytes();                               \
   150       len = name->utf8_length();                                 \
   151     }                                                            \
   152     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
   153       data, len, (clss)->class_loader(), thread_type, wait);     \
   154   }
   155 #endif /* USDT2 */
   157 #else //  ndef DTRACE_ENABLED
   159 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
   160 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
   162 #endif //  ndef DTRACE_ENABLED
   164 volatile int InstanceKlass::_total_instanceKlass_count = 0;
   166 Klass* InstanceKlass::allocate_instance_klass(ClassLoaderData* loader_data,
   167                                                 int vtable_len,
   168                                                 int itable_len,
   169                                                 int static_field_size,
   170                                                 int nonstatic_oop_map_size,
   171                                                 ReferenceType rt,
   172                                                 AccessFlags access_flags,
   173                                                 Symbol* name,
   174                                               Klass* super_klass,
   175                                                 KlassHandle host_klass,
   176                                                 TRAPS) {
   178   int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
   179                                  access_flags.is_interface(),
   180                                  !host_klass.is_null());
   182   // Allocation
   183   InstanceKlass* ik;
   184   if (rt == REF_NONE) {
   185     if (name == vmSymbols::java_lang_Class()) {
   186       ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
   187         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   188         access_flags, !host_klass.is_null());
   189     } else if (name == vmSymbols::java_lang_ClassLoader() ||
   190           (SystemDictionary::ClassLoader_klass_loaded() &&
   191           super_klass != NULL &&
   192           super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
   193       ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
   194         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   195         access_flags, !host_klass.is_null());
   196     } else {
   197       // normal class
   198       ik = new (loader_data, size, THREAD) InstanceKlass(
   199         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   200         access_flags, !host_klass.is_null());
   201     }
   202   } else {
   203     // reference klass
   204     ik = new (loader_data, size, THREAD) InstanceRefKlass(
   205         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   206         access_flags, !host_klass.is_null());
   207   }
   209   Atomic::inc(&_total_instanceKlass_count);
   210   return ik;
   211 }
   213 InstanceKlass::InstanceKlass(int vtable_len,
   214                              int itable_len,
   215                              int static_field_size,
   216                              int nonstatic_oop_map_size,
   217                              ReferenceType rt,
   218                              AccessFlags access_flags,
   219                              bool is_anonymous) {
   220   No_Safepoint_Verifier no_safepoint; // until k becomes parsable
   222   int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
   223                                  access_flags.is_interface(), is_anonymous);
   225   // The sizes of these these three variables are used for determining the
   226   // size of the instanceKlassOop. It is critical that these are set to the right
   227   // sizes before the first GC, i.e., when we allocate the mirror.
   228   this->set_vtable_length(vtable_len);
   229   this->set_itable_length(itable_len);
   230   this->set_static_field_size(static_field_size);
   231   this->set_nonstatic_oop_map_size(nonstatic_oop_map_size);
   232   this->set_access_flags(access_flags);
   233   this->set_is_anonymous(is_anonymous);
   234   assert(this->size() == size, "wrong size for object");
   236   this->set_array_klasses(NULL);
   237   this->set_methods(NULL);
   238   this->set_method_ordering(NULL);
   239   this->set_local_interfaces(NULL);
   240   this->set_transitive_interfaces(NULL);
   241   this->init_implementor();
   242   this->set_fields(NULL, 0);
   243   this->set_constants(NULL);
   244   this->set_class_loader_data(NULL);
   245   this->set_protection_domain(NULL);
   246   this->set_signers(NULL);
   247   this->set_source_file_name(NULL);
   248   this->set_source_debug_extension(NULL, 0);
   249   this->set_array_name(NULL);
   250   this->set_inner_classes(NULL);
   251   this->set_static_oop_field_count(0);
   252   this->set_nonstatic_field_size(0);
   253   this->set_is_marked_dependent(false);
   254   this->set_init_state(InstanceKlass::allocated);
   255   this->set_init_thread(NULL);
   256   this->set_init_lock(NULL);
   257   this->set_reference_type(rt);
   258   this->set_oop_map_cache(NULL);
   259   this->set_jni_ids(NULL);
   260   this->set_osr_nmethods_head(NULL);
   261   this->set_breakpoints(NULL);
   262   this->init_previous_versions();
   263   this->set_generic_signature(NULL);
   264   this->release_set_methods_jmethod_ids(NULL);
   265   this->release_set_methods_cached_itable_indices(NULL);
   266   this->set_annotations(NULL);
   267   this->set_jvmti_cached_class_field_map(NULL);
   268   this->set_initial_method_idnum(0);
   270   // initialize the non-header words to zero
   271   intptr_t* p = (intptr_t*)this;
   272   for (int index = InstanceKlass::header_size(); index < size; index++) {
   273     p[index] = NULL_WORD;
   274   }
   276   // Set temporary value until parseClassFile updates it with the real instance
   277   // size.
   278   this->set_layout_helper(Klass::instance_layout_helper(0, true));
   279 }
   282 // This function deallocates the metadata and C heap pointers that the
   283 // InstanceKlass points to.
   284 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
   286   // Orphan the mirror first, CMS thinks it's still live.
   287   java_lang_Class::set_klass(java_mirror(), NULL);
   289   // Need to take this class off the class loader data list.
   290   loader_data->remove_class(this);
   292   // The array_klass for this class is created later, after error handling.
   293   // For class redefinition, we keep the original class so this scratch class
   294   // doesn't have an array class.  Either way, assert that there is nothing
   295   // to deallocate.
   296   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
   298   // Release C heap allocated data that this might point to, which includes
   299   // reference counting symbol names.
   300   release_C_heap_structures();
   302   Array<Method*>* ms = methods();
   303   if (ms != Universe::the_empty_method_array()) {
   304     for (int i = 0; i <= methods()->length() -1 ; i++) {
   305       Method* method = methods()->at(i);
   306       // Only want to delete methods that are not executing for RedefineClasses.
   307       // The previous version will point to them so they're not totally dangling
   308       assert (!method->on_stack(), "shouldn't be called with methods on stack");
   309       MetadataFactory::free_metadata(loader_data, method);
   310     }
   311     MetadataFactory::free_array<Method*>(loader_data, methods());
   312   }
   313   set_methods(NULL);
   315   if (method_ordering() != Universe::the_empty_int_array()) {
   316     MetadataFactory::free_array<int>(loader_data, method_ordering());
   317   }
   318   set_method_ordering(NULL);
   320   // This array is in Klass, but remove it with the InstanceKlass since
   321   // this place would be the only caller and it can share memory with transitive
   322   // interfaces.
   323   if (secondary_supers() != Universe::the_empty_klass_array() &&
   324       secondary_supers() != transitive_interfaces()) {
   325     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
   326   }
   327   set_secondary_supers(NULL);
   329   // Only deallocate transitive interfaces if not empty, same as super class
   330   // or same as local interfaces.   See code in parseClassFile.
   331   Array<Klass*>* ti = transitive_interfaces();
   332   if (ti != Universe::the_empty_klass_array() && ti != local_interfaces()) {
   333     // check that the interfaces don't come from super class
   334     Array<Klass*>* sti = (super() == NULL) ? NULL :
   335        InstanceKlass::cast(super())->transitive_interfaces();
   336     if (ti != sti) {
   337       MetadataFactory::free_array<Klass*>(loader_data, ti);
   338     }
   339   }
   340   set_transitive_interfaces(NULL);
   342   // local interfaces can be empty
   343   Array<Klass*>* li = local_interfaces();
   344   if (li != Universe::the_empty_klass_array()) {
   345     MetadataFactory::free_array<Klass*>(loader_data, li);
   346   }
   347   set_local_interfaces(NULL);
   349   MetadataFactory::free_array<jushort>(loader_data, fields());
   350   set_fields(NULL, 0);
   352   // If a method from a redefined class is using this constant pool, don't
   353   // delete it, yet.  The new class's previous version will point to this.
   354   assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
   355   MetadataFactory::free_metadata(loader_data, constants());
   356   set_constants(NULL);
   358   if (inner_classes() != Universe::the_empty_short_array()) {
   359     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
   360   }
   361   set_inner_classes(NULL);
   363   // Null out Java heap objects, although these won't be walked to keep
   364   // alive once this InstanceKlass is deallocated.
   365   set_protection_domain(NULL);
   366   set_signers(NULL);
   367   set_init_lock(NULL);
   369   // We should deallocate the Annotations instance
   370   MetadataFactory::free_metadata(loader_data, annotations());
   371   set_annotations(NULL);
   372 }
   374 volatile oop InstanceKlass::init_lock() const {
   375   volatile oop lock = _init_lock;  // read once
   376   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
   377          "only fully initialized state can have a null lock");
   378   return lock;
   379 }
   381 // Set the initialization lock to null so the object can be GC'ed.  Any racing
   382 // threads to get this lock will see a null lock and will not lock.
   383 // That's okay because they all check for initialized state after getting
   384 // the lock and return.
   385 void InstanceKlass::fence_and_clear_init_lock() {
   386   // make sure previous stores are all done, notably the init_state.
   387   OrderAccess::storestore();
   388   klass_oop_store(&_init_lock, NULL);
   389   assert(!is_not_initialized(), "class must be initialized now");
   390 }
   393 bool InstanceKlass::should_be_initialized() const {
   394   return !is_initialized();
   395 }
   397 klassVtable* InstanceKlass::vtable() const {
   398   return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
   399 }
   401 klassItable* InstanceKlass::itable() const {
   402   return new klassItable(instanceKlassHandle(this));
   403 }
   405 void InstanceKlass::eager_initialize(Thread *thread) {
   406   if (!EagerInitialization) return;
   408   if (this->is_not_initialized()) {
   409     // abort if the the class has a class initializer
   410     if (this->class_initializer() != NULL) return;
   412     // abort if it is java.lang.Object (initialization is handled in genesis)
   413     Klass* super = this->super();
   414     if (super == NULL) return;
   416     // abort if the super class should be initialized
   417     if (!InstanceKlass::cast(super)->is_initialized()) return;
   419     // call body to expose the this pointer
   420     instanceKlassHandle this_oop(thread, this);
   421     eager_initialize_impl(this_oop);
   422   }
   423 }
   426 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
   427   EXCEPTION_MARK;
   428   volatile oop init_lock = this_oop->init_lock();
   429   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   431   // abort if someone beat us to the initialization
   432   if (!this_oop->is_not_initialized()) return;  // note: not equivalent to is_initialized()
   434   ClassState old_state = this_oop->init_state();
   435   link_class_impl(this_oop, true, THREAD);
   436   if (HAS_PENDING_EXCEPTION) {
   437     CLEAR_PENDING_EXCEPTION;
   438     // Abort if linking the class throws an exception.
   440     // Use a test to avoid redundantly resetting the state if there's
   441     // no change.  Set_init_state() asserts that state changes make
   442     // progress, whereas here we might just be spinning in place.
   443     if( old_state != this_oop->_init_state )
   444       this_oop->set_init_state (old_state);
   445   } else {
   446     // linking successfull, mark class as initialized
   447     this_oop->set_init_state (fully_initialized);
   448     this_oop->fence_and_clear_init_lock();
   449     // trace
   450     if (TraceClassInitialization) {
   451       ResourceMark rm(THREAD);
   452       tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
   453     }
   454   }
   455 }
   458 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
   459 // process. The step comments refers to the procedure described in that section.
   460 // Note: implementation moved to static method to expose the this pointer.
   461 void InstanceKlass::initialize(TRAPS) {
   462   if (this->should_be_initialized()) {
   463     HandleMark hm(THREAD);
   464     instanceKlassHandle this_oop(THREAD, this);
   465     initialize_impl(this_oop, CHECK);
   466     // Note: at this point the class may be initialized
   467     //       OR it may be in the state of being initialized
   468     //       in case of recursive initialization!
   469   } else {
   470     assert(is_initialized(), "sanity check");
   471   }
   472 }
   475 bool InstanceKlass::verify_code(
   476     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
   477   // 1) Verify the bytecodes
   478   Verifier::Mode mode =
   479     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
   480   return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
   481 }
   484 // Used exclusively by the shared spaces dump mechanism to prevent
   485 // classes mapped into the shared regions in new VMs from appearing linked.
   487 void InstanceKlass::unlink_class() {
   488   assert(is_linked(), "must be linked");
   489   _init_state = loaded;
   490 }
   492 void InstanceKlass::link_class(TRAPS) {
   493   assert(is_loaded(), "must be loaded");
   494   if (!is_linked()) {
   495     HandleMark hm(THREAD);
   496     instanceKlassHandle this_oop(THREAD, this);
   497     link_class_impl(this_oop, true, CHECK);
   498   }
   499 }
   501 // Called to verify that a class can link during initialization, without
   502 // throwing a VerifyError.
   503 bool InstanceKlass::link_class_or_fail(TRAPS) {
   504   assert(is_loaded(), "must be loaded");
   505   if (!is_linked()) {
   506     HandleMark hm(THREAD);
   507     instanceKlassHandle this_oop(THREAD, this);
   508     link_class_impl(this_oop, false, CHECK_false);
   509   }
   510   return is_linked();
   511 }
   513 bool InstanceKlass::link_class_impl(
   514     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
   515   // check for error state
   516   if (this_oop->is_in_error_state()) {
   517     ResourceMark rm(THREAD);
   518     THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
   519                this_oop->external_name(), false);
   520   }
   521   // return if already verified
   522   if (this_oop->is_linked()) {
   523     return true;
   524   }
   526   // Timing
   527   // timer handles recursion
   528   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
   529   JavaThread* jt = (JavaThread*)THREAD;
   531   // link super class before linking this class
   532   instanceKlassHandle super(THREAD, this_oop->super());
   533   if (super.not_null()) {
   534     if (super->is_interface()) {  // check if super class is an interface
   535       ResourceMark rm(THREAD);
   536       Exceptions::fthrow(
   537         THREAD_AND_LOCATION,
   538         vmSymbols::java_lang_IncompatibleClassChangeError(),
   539         "class %s has interface %s as super class",
   540         this_oop->external_name(),
   541         super->external_name()
   542       );
   543       return false;
   544     }
   546     link_class_impl(super, throw_verifyerror, CHECK_false);
   547   }
   549   // link all interfaces implemented by this class before linking this class
   550   Array<Klass*>* interfaces = this_oop->local_interfaces();
   551   int num_interfaces = interfaces->length();
   552   for (int index = 0; index < num_interfaces; index++) {
   553     HandleMark hm(THREAD);
   554     instanceKlassHandle ih(THREAD, interfaces->at(index));
   555     link_class_impl(ih, throw_verifyerror, CHECK_false);
   556   }
   558   // in case the class is linked in the process of linking its superclasses
   559   if (this_oop->is_linked()) {
   560     return true;
   561   }
   563   // trace only the link time for this klass that includes
   564   // the verification time
   565   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
   566                              ClassLoader::perf_class_link_selftime(),
   567                              ClassLoader::perf_classes_linked(),
   568                              jt->get_thread_stat()->perf_recursion_counts_addr(),
   569                              jt->get_thread_stat()->perf_timers_addr(),
   570                              PerfClassTraceTime::CLASS_LINK);
   572   // verification & rewriting
   573   {
   574     volatile oop init_lock = this_oop->init_lock();
   575     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   576     // rewritten will have been set if loader constraint error found
   577     // on an earlier link attempt
   578     // don't verify or rewrite if already rewritten
   580     if (!this_oop->is_linked()) {
   581       if (!this_oop->is_rewritten()) {
   582         {
   583           // Timer includes any side effects of class verification (resolution,
   584           // etc), but not recursive entry into verify_code().
   585           PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
   586                                    ClassLoader::perf_class_verify_selftime(),
   587                                    ClassLoader::perf_classes_verified(),
   588                                    jt->get_thread_stat()->perf_recursion_counts_addr(),
   589                                    jt->get_thread_stat()->perf_timers_addr(),
   590                                    PerfClassTraceTime::CLASS_VERIFY);
   591           bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
   592           if (!verify_ok) {
   593             return false;
   594           }
   595         }
   597         // Just in case a side-effect of verify linked this class already
   598         // (which can sometimes happen since the verifier loads classes
   599         // using custom class loaders, which are free to initialize things)
   600         if (this_oop->is_linked()) {
   601           return true;
   602         }
   604         // also sets rewritten
   605         this_oop->rewrite_class(CHECK_false);
   606       }
   608       // relocate jsrs and link methods after they are all rewritten
   609       this_oop->link_methods(CHECK_false);
   611       // Initialize the vtable and interface table after
   612       // methods have been rewritten since rewrite may
   613       // fabricate new Method*s.
   614       // also does loader constraint checking
   615       if (!this_oop()->is_shared()) {
   616         ResourceMark rm(THREAD);
   617         this_oop->vtable()->initialize_vtable(true, CHECK_false);
   618         this_oop->itable()->initialize_itable(true, CHECK_false);
   619       }
   620 #ifdef ASSERT
   621       else {
   622         ResourceMark rm(THREAD);
   623         this_oop->vtable()->verify(tty, true);
   624         // In case itable verification is ever added.
   625         // this_oop->itable()->verify(tty, true);
   626       }
   627 #endif
   628       this_oop->set_init_state(linked);
   629       if (JvmtiExport::should_post_class_prepare()) {
   630         Thread *thread = THREAD;
   631         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
   632         JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
   633       }
   634     }
   635   }
   636   return true;
   637 }
   640 // Rewrite the byte codes of all of the methods of a class.
   641 // The rewriter must be called exactly once. Rewriting must happen after
   642 // verification but before the first method of the class is executed.
   643 void InstanceKlass::rewrite_class(TRAPS) {
   644   assert(is_loaded(), "must be loaded");
   645   instanceKlassHandle this_oop(THREAD, this);
   646   if (this_oop->is_rewritten()) {
   647     assert(this_oop()->is_shared(), "rewriting an unshared class?");
   648     return;
   649   }
   650   Rewriter::rewrite(this_oop, CHECK);
   651   this_oop->set_rewritten();
   652 }
   654 // Now relocate and link method entry points after class is rewritten.
   655 // This is outside is_rewritten flag. In case of an exception, it can be
   656 // executed more than once.
   657 void InstanceKlass::link_methods(TRAPS) {
   658   int len = methods()->length();
   659   for (int i = len-1; i >= 0; i--) {
   660     methodHandle m(THREAD, methods()->at(i));
   662     // Set up method entry points for compiler and interpreter    .
   663     m->link_method(m, CHECK);
   665     // This is for JVMTI and unrelated to relocator but the last thing we do
   666 #ifdef ASSERT
   667     if (StressMethodComparator) {
   668       ResourceMark rm(THREAD);
   669       static int nmc = 0;
   670       for (int j = i; j >= 0 && j >= i-4; j--) {
   671         if ((++nmc % 1000) == 0)  tty->print_cr("Have run MethodComparator %d times...", nmc);
   672         bool z = MethodComparator::methods_EMCP(m(),
   673                    methods()->at(j));
   674         if (j == i && !z) {
   675           tty->print("MethodComparator FAIL: "); m->print(); m->print_codes();
   676           assert(z, "method must compare equal to itself");
   677         }
   678       }
   679     }
   680 #endif //ASSERT
   681   }
   682 }
   685 void InstanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
   686   // Make sure klass is linked (verified) before initialization
   687   // A class could already be verified, since it has been reflected upon.
   688   this_oop->link_class(CHECK);
   690   DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_oop()), -1);
   692   bool wait = false;
   694   // refer to the JVM book page 47 for description of steps
   695   // Step 1
   696   {
   697     volatile oop init_lock = this_oop->init_lock();
   698     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   700     Thread *self = THREAD; // it's passed the current thread
   702     // Step 2
   703     // If we were to use wait() instead of waitInterruptibly() then
   704     // we might end up throwing IE from link/symbol resolution sites
   705     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
   706     while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
   707         wait = true;
   708       ol.waitUninterruptibly(CHECK);
   709     }
   711     // Step 3
   712     if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
   713       DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_oop()), -1,wait);
   714       return;
   715     }
   717     // Step 4
   718     if (this_oop->is_initialized()) {
   719       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_oop()), -1,wait);
   720       return;
   721     }
   723     // Step 5
   724     if (this_oop->is_in_error_state()) {
   725       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_oop()), -1,wait);
   726       ResourceMark rm(THREAD);
   727       const char* desc = "Could not initialize class ";
   728       const char* className = this_oop->external_name();
   729       size_t msglen = strlen(desc) + strlen(className) + 1;
   730       char* message = NEW_RESOURCE_ARRAY(char, msglen);
   731       if (NULL == message) {
   732         // Out of memory: can't create detailed error message
   733         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
   734       } else {
   735         jio_snprintf(message, msglen, "%s%s", desc, className);
   736         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
   737       }
   738     }
   740     // Step 6
   741     this_oop->set_init_state(being_initialized);
   742     this_oop->set_init_thread(self);
   743   }
   745   // Step 7
   746   Klass* super_klass = this_oop->super();
   747   if (super_klass != NULL && !this_oop->is_interface() && super_klass->should_be_initialized()) {
   748     super_klass->initialize(THREAD);
   750     if (HAS_PENDING_EXCEPTION) {
   751       Handle e(THREAD, PENDING_EXCEPTION);
   752       CLEAR_PENDING_EXCEPTION;
   753       {
   754         EXCEPTION_MARK;
   755         this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
   756         CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, superclass initialization error is thrown below
   757       }
   758       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_oop()), -1,wait);
   759       THROW_OOP(e());
   760     }
   761   }
   763   if (this_oop->has_default_methods()) {
   764     // Step 7.5: initialize any interfaces which have default methods
   765     for (int i = 0; i < this_oop->local_interfaces()->length(); ++i) {
   766       Klass* iface = this_oop->local_interfaces()->at(i);
   767       InstanceKlass* ik = InstanceKlass::cast(iface);
   768       if (ik->has_default_methods() && ik->should_be_initialized()) {
   769         ik->initialize(THREAD);
   771         if (HAS_PENDING_EXCEPTION) {
   772           Handle e(THREAD, PENDING_EXCEPTION);
   773           CLEAR_PENDING_EXCEPTION;
   774           {
   775             EXCEPTION_MARK;
   776             // Locks object, set state, and notify all waiting threads
   777             this_oop->set_initialization_state_and_notify(
   778                 initialization_error, THREAD);
   780             // ignore any exception thrown, superclass initialization error is
   781             // thrown below
   782             CLEAR_PENDING_EXCEPTION;
   783           }
   784           DTRACE_CLASSINIT_PROBE_WAIT(
   785               super__failed, InstanceKlass::cast(this_oop()), -1, wait);
   786           THROW_OOP(e());
   787         }
   788       }
   789     }
   790   }
   792   // Step 8
   793   {
   794     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
   795     JavaThread* jt = (JavaThread*)THREAD;
   796     DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_oop()), -1,wait);
   797     // Timer includes any side effects of class initialization (resolution,
   798     // etc), but not recursive entry into call_class_initializer().
   799     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
   800                              ClassLoader::perf_class_init_selftime(),
   801                              ClassLoader::perf_classes_inited(),
   802                              jt->get_thread_stat()->perf_recursion_counts_addr(),
   803                              jt->get_thread_stat()->perf_timers_addr(),
   804                              PerfClassTraceTime::CLASS_CLINIT);
   805     this_oop->call_class_initializer(THREAD);
   806   }
   808   // Step 9
   809   if (!HAS_PENDING_EXCEPTION) {
   810     this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
   811     { ResourceMark rm(THREAD);
   812       debug_only(this_oop->vtable()->verify(tty, true);)
   813     }
   814   }
   815   else {
   816     // Step 10 and 11
   817     Handle e(THREAD, PENDING_EXCEPTION);
   818     CLEAR_PENDING_EXCEPTION;
   819     {
   820       EXCEPTION_MARK;
   821       this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
   822       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
   823     }
   824     DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_oop()), -1,wait);
   825     if (e->is_a(SystemDictionary::Error_klass())) {
   826       THROW_OOP(e());
   827     } else {
   828       JavaCallArguments args(e);
   829       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
   830                 vmSymbols::throwable_void_signature(),
   831                 &args);
   832     }
   833   }
   834   DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_oop()), -1,wait);
   835 }
   838 // Note: implementation moved to static method to expose the this pointer.
   839 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
   840   instanceKlassHandle kh(THREAD, this);
   841   set_initialization_state_and_notify_impl(kh, state, CHECK);
   842 }
   844 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
   845   volatile oop init_lock = this_oop->init_lock();
   846   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   847   this_oop->set_init_state(state);
   848   this_oop->fence_and_clear_init_lock();
   849   ol.notify_all(CHECK);
   850 }
   852 // The embedded _implementor field can only record one implementor.
   853 // When there are more than one implementors, the _implementor field
   854 // is set to the interface Klass* itself. Following are the possible
   855 // values for the _implementor field:
   856 //   NULL                  - no implementor
   857 //   implementor Klass*    - one implementor
   858 //   self                  - more than one implementor
   859 //
   860 // The _implementor field only exists for interfaces.
   861 void InstanceKlass::add_implementor(Klass* k) {
   862   assert(Compile_lock->owned_by_self(), "");
   863   assert(is_interface(), "not interface");
   864   // Filter out my subinterfaces.
   865   // (Note: Interfaces are never on the subklass list.)
   866   if (InstanceKlass::cast(k)->is_interface()) return;
   868   // Filter out subclasses whose supers already implement me.
   869   // (Note: CHA must walk subclasses of direct implementors
   870   // in order to locate indirect implementors.)
   871   Klass* sk = InstanceKlass::cast(k)->super();
   872   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
   873     // We only need to check one immediate superclass, since the
   874     // implements_interface query looks at transitive_interfaces.
   875     // Any supers of the super have the same (or fewer) transitive_interfaces.
   876     return;
   878   Klass* ik = implementor();
   879   if (ik == NULL) {
   880     set_implementor(k);
   881   } else if (ik != this) {
   882     // There is already an implementor. Use itself as an indicator of
   883     // more than one implementors.
   884     set_implementor(this);
   885   }
   887   // The implementor also implements the transitive_interfaces
   888   for (int index = 0; index < local_interfaces()->length(); index++) {
   889     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
   890   }
   891 }
   893 void InstanceKlass::init_implementor() {
   894   if (is_interface()) {
   895     set_implementor(NULL);
   896   }
   897 }
   900 void InstanceKlass::process_interfaces(Thread *thread) {
   901   // link this class into the implementors list of every interface it implements
   902   Klass* this_as_klass_oop = this;
   903   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
   904     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
   905     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
   906     assert(interf->is_interface(), "expected interface");
   907     interf->add_implementor(this_as_klass_oop);
   908   }
   909 }
   911 bool InstanceKlass::can_be_primary_super_slow() const {
   912   if (is_interface())
   913     return false;
   914   else
   915     return Klass::can_be_primary_super_slow();
   916 }
   918 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
   919   // The secondaries are the implemented interfaces.
   920   InstanceKlass* ik = InstanceKlass::cast(this);
   921   Array<Klass*>* interfaces = ik->transitive_interfaces();
   922   int num_secondaries = num_extra_slots + interfaces->length();
   923   if (num_secondaries == 0) {
   924     // Must share this for correct bootstrapping!
   925     set_secondary_supers(Universe::the_empty_klass_array());
   926     return NULL;
   927   } else if (num_extra_slots == 0) {
   928     // The secondary super list is exactly the same as the transitive interfaces.
   929     // Redefine classes has to be careful not to delete this!
   930     set_secondary_supers(interfaces);
   931     return NULL;
   932   } else {
   933     // Copy transitive interfaces to a temporary growable array to be constructed
   934     // into the secondary super list with extra slots.
   935     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
   936     for (int i = 0; i < interfaces->length(); i++) {
   937       secondaries->push(interfaces->at(i));
   938     }
   939     return secondaries;
   940   }
   941 }
   943 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
   944   if (k->is_interface()) {
   945     return implements_interface(k);
   946   } else {
   947     return Klass::compute_is_subtype_of(k);
   948   }
   949 }
   951 bool InstanceKlass::implements_interface(Klass* k) const {
   952   if (this == k) return true;
   953   assert(k->is_interface(), "should be an interface class");
   954   for (int i = 0; i < transitive_interfaces()->length(); i++) {
   955     if (transitive_interfaces()->at(i) == k) {
   956       return true;
   957     }
   958   }
   959   return false;
   960 }
   962 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
   963   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
   964   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
   965     report_java_out_of_memory("Requested array size exceeds VM limit");
   966     JvmtiExport::post_array_size_exhausted();
   967     THROW_OOP_0(Universe::out_of_memory_error_array_size());
   968   }
   969   int size = objArrayOopDesc::object_size(length);
   970   Klass* ak = array_klass(n, CHECK_NULL);
   971   KlassHandle h_ak (THREAD, ak);
   972   objArrayOop o =
   973     (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
   974   return o;
   975 }
   977 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
   978   if (TraceFinalizerRegistration) {
   979     tty->print("Registered ");
   980     i->print_value_on(tty);
   981     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
   982   }
   983   instanceHandle h_i(THREAD, i);
   984   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
   985   JavaValue result(T_VOID);
   986   JavaCallArguments args(h_i);
   987   methodHandle mh (THREAD, Universe::finalizer_register_method());
   988   JavaCalls::call(&result, mh, &args, CHECK_NULL);
   989   return h_i();
   990 }
   992 instanceOop InstanceKlass::allocate_instance(TRAPS) {
   993   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
   994   int size = size_helper();  // Query before forming handle.
   996   KlassHandle h_k(THREAD, this);
   998   instanceOop i;
  1000   i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
  1001   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
  1002     i = register_finalizer(i, CHECK_NULL);
  1004   return i;
  1007 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
  1008   if (is_interface() || is_abstract()) {
  1009     ResourceMark rm(THREAD);
  1010     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
  1011               : vmSymbols::java_lang_InstantiationException(), external_name());
  1013   if (this == SystemDictionary::Class_klass()) {
  1014     ResourceMark rm(THREAD);
  1015     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
  1016               : vmSymbols::java_lang_IllegalAccessException(), external_name());
  1020 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
  1021   instanceKlassHandle this_oop(THREAD, this);
  1022   return array_klass_impl(this_oop, or_null, n, THREAD);
  1025 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
  1026   if (this_oop->array_klasses() == NULL) {
  1027     if (or_null) return NULL;
  1029     ResourceMark rm;
  1030     JavaThread *jt = (JavaThread *)THREAD;
  1032       // Atomic creation of array_klasses
  1033       MutexLocker mc(Compile_lock, THREAD);   // for vtables
  1034       MutexLocker ma(MultiArray_lock, THREAD);
  1036       // Check if update has already taken place
  1037       if (this_oop->array_klasses() == NULL) {
  1038         Klass*    k = ObjArrayKlass::allocate_objArray_klass(this_oop->class_loader_data(), 1, this_oop, CHECK_NULL);
  1039         this_oop->set_array_klasses(k);
  1043   // _this will always be set at this point
  1044   ObjArrayKlass* oak = (ObjArrayKlass*)this_oop->array_klasses();
  1045   if (or_null) {
  1046     return oak->array_klass_or_null(n);
  1048   return oak->array_klass(n, CHECK_NULL);
  1051 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
  1052   return array_klass_impl(or_null, 1, THREAD);
  1055 void InstanceKlass::call_class_initializer(TRAPS) {
  1056   instanceKlassHandle ik (THREAD, this);
  1057   call_class_initializer_impl(ik, THREAD);
  1060 static int call_class_initializer_impl_counter = 0;   // for debugging
  1062 Method* InstanceKlass::class_initializer() {
  1063   Method* clinit = find_method(
  1064       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
  1065   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
  1066     return clinit;
  1068   return NULL;
  1071 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
  1072   if (ReplayCompiles &&
  1073       (ReplaySuppressInitializers == 1 ||
  1074        ReplaySuppressInitializers >= 2 && this_oop->class_loader() != NULL)) {
  1075     // Hide the existence of the initializer for the purpose of replaying the compile
  1076     return;
  1079   methodHandle h_method(THREAD, this_oop->class_initializer());
  1080   assert(!this_oop->is_initialized(), "we cannot initialize twice");
  1081   if (TraceClassInitialization) {
  1082     tty->print("%d Initializing ", call_class_initializer_impl_counter++);
  1083     this_oop->name()->print_value();
  1084     tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
  1086   if (h_method() != NULL) {
  1087     JavaCallArguments args; // No arguments
  1088     JavaValue result(T_VOID);
  1089     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
  1094 void InstanceKlass::mask_for(methodHandle method, int bci,
  1095   InterpreterOopMap* entry_for) {
  1096   // Dirty read, then double-check under a lock.
  1097   if (_oop_map_cache == NULL) {
  1098     // Otherwise, allocate a new one.
  1099     MutexLocker x(OopMapCacheAlloc_lock);
  1100     // First time use. Allocate a cache in C heap
  1101     if (_oop_map_cache == NULL) {
  1102       _oop_map_cache = new OopMapCache();
  1105   // _oop_map_cache is constant after init; lookup below does is own locking.
  1106   _oop_map_cache->lookup(method, bci, entry_for);
  1110 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  1111   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
  1112     Symbol* f_name = fs.name();
  1113     Symbol* f_sig  = fs.signature();
  1114     if (f_name == name && f_sig == sig) {
  1115       fd->initialize(const_cast<InstanceKlass*>(this), fs.index());
  1116       return true;
  1119   return false;
  1123 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  1124   const int n = local_interfaces()->length();
  1125   for (int i = 0; i < n; i++) {
  1126     Klass* intf1 = local_interfaces()->at(i);
  1127     assert(intf1->is_interface(), "just checking type");
  1128     // search for field in current interface
  1129     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
  1130       assert(fd->is_static(), "interface field must be static");
  1131       return intf1;
  1133     // search for field in direct superinterfaces
  1134     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
  1135     if (intf2 != NULL) return intf2;
  1137   // otherwise field lookup fails
  1138   return NULL;
  1142 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  1143   // search order according to newest JVM spec (5.4.3.2, p.167).
  1144   // 1) search for field in current klass
  1145   if (find_local_field(name, sig, fd)) {
  1146     return const_cast<InstanceKlass*>(this);
  1148   // 2) search for field recursively in direct superinterfaces
  1149   { Klass* intf = find_interface_field(name, sig, fd);
  1150     if (intf != NULL) return intf;
  1152   // 3) apply field lookup recursively if superclass exists
  1153   { Klass* supr = super();
  1154     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
  1156   // 4) otherwise field lookup fails
  1157   return NULL;
  1161 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
  1162   // search order according to newest JVM spec (5.4.3.2, p.167).
  1163   // 1) search for field in current klass
  1164   if (find_local_field(name, sig, fd)) {
  1165     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
  1167   // 2) search for field recursively in direct superinterfaces
  1168   if (is_static) {
  1169     Klass* intf = find_interface_field(name, sig, fd);
  1170     if (intf != NULL) return intf;
  1172   // 3) apply field lookup recursively if superclass exists
  1173   { Klass* supr = super();
  1174     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
  1176   // 4) otherwise field lookup fails
  1177   return NULL;
  1181 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
  1182   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
  1183     if (fs.offset() == offset) {
  1184       fd->initialize(const_cast<InstanceKlass*>(this), fs.index());
  1185       if (fd->is_static() == is_static) return true;
  1188   return false;
  1192 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
  1193   Klass* klass = const_cast<InstanceKlass*>(this);
  1194   while (klass != NULL) {
  1195     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
  1196       return true;
  1198     klass = klass->super();
  1200   return false;
  1204 void InstanceKlass::methods_do(void f(Method* method)) {
  1205   int len = methods()->length();
  1206   for (int index = 0; index < len; index++) {
  1207     Method* m = methods()->at(index);
  1208     assert(m->is_method(), "must be method");
  1209     f(m);
  1214 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
  1215   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
  1216     if (fs.access_flags().is_static()) {
  1217       fieldDescriptor fd;
  1218       fd.initialize(this, fs.index());
  1219       cl->do_field(&fd);
  1225 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
  1226   instanceKlassHandle h_this(THREAD, this);
  1227   do_local_static_fields_impl(h_this, f, CHECK);
  1231 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
  1232   for (JavaFieldStream fs(this_oop()); !fs.done(); fs.next()) {
  1233     if (fs.access_flags().is_static()) {
  1234       fieldDescriptor fd;
  1235       fd.initialize(this_oop(), fs.index());
  1236       f(&fd, CHECK);
  1242 static int compare_fields_by_offset(int* a, int* b) {
  1243   return a[0] - b[0];
  1246 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
  1247   InstanceKlass* super = superklass();
  1248   if (super != NULL) {
  1249     super->do_nonstatic_fields(cl);
  1251   fieldDescriptor fd;
  1252   int length = java_fields_count();
  1253   // In DebugInfo nonstatic fields are sorted by offset.
  1254   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
  1255   int j = 0;
  1256   for (int i = 0; i < length; i += 1) {
  1257     fd.initialize(this, i);
  1258     if (!fd.is_static()) {
  1259       fields_sorted[j + 0] = fd.offset();
  1260       fields_sorted[j + 1] = i;
  1261       j += 2;
  1264   if (j > 0) {
  1265     length = j;
  1266     // _sort_Fn is defined in growableArray.hpp.
  1267     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
  1268     for (int i = 0; i < length; i += 2) {
  1269       fd.initialize(this, fields_sorted[i + 1]);
  1270       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
  1271       cl->do_field(&fd);
  1274   FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
  1278 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
  1279   if (array_klasses() != NULL)
  1280     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
  1283 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
  1284   if (array_klasses() != NULL)
  1285     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
  1289 void InstanceKlass::with_array_klasses_do(void f(Klass* k)) {
  1290   f(this);
  1291   array_klasses_do(f);
  1294 #ifdef ASSERT
  1295 static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
  1296   int len = methods->length();
  1297   for (int index = 0; index < len; index++) {
  1298     Method* m = methods->at(index);
  1299     assert(m->is_method(), "must be method");
  1300     if (m->signature() == signature && m->name() == name) {
  1301        return index;
  1304   return -1;
  1306 #endif
  1308 static int binary_search(Array<Method*>* methods, Symbol* name) {
  1309   int len = methods->length();
  1310   // methods are sorted, so do binary search
  1311   int l = 0;
  1312   int h = len - 1;
  1313   while (l <= h) {
  1314     int mid = (l + h) >> 1;
  1315     Method* m = methods->at(mid);
  1316     assert(m->is_method(), "must be method");
  1317     int res = m->name()->fast_compare(name);
  1318     if (res == 0) {
  1319       return mid;
  1320     } else if (res < 0) {
  1321       l = mid + 1;
  1322     } else {
  1323       h = mid - 1;
  1326   return -1;
  1329 Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
  1330   return InstanceKlass::find_method(methods(), name, signature);
  1333 Method* InstanceKlass::find_method(
  1334     Array<Method*>* methods, Symbol* name, Symbol* signature) {
  1335   int hit = binary_search(methods, name);
  1336   if (hit != -1) {
  1337     Method* m = methods->at(hit);
  1338     // Do linear search to find matching signature.  First, quick check
  1339     // for common case
  1340     if (m->signature() == signature) return m;
  1341     // search downwards through overloaded methods
  1342     int i;
  1343     for (i = hit - 1; i >= 0; --i) {
  1344         Method* m = methods->at(i);
  1345         assert(m->is_method(), "must be method");
  1346         if (m->name() != name) break;
  1347         if (m->signature() == signature) return m;
  1349     // search upwards
  1350     for (i = hit + 1; i < methods->length(); ++i) {
  1351         Method* m = methods->at(i);
  1352         assert(m->is_method(), "must be method");
  1353         if (m->name() != name) break;
  1354         if (m->signature() == signature) return m;
  1356     // not found
  1357 #ifdef ASSERT
  1358     int index = linear_search(methods, name, signature);
  1359     assert(index == -1, err_msg("binary search should have found entry %d", index));
  1360 #endif
  1362   return NULL;
  1365 int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
  1366   return find_method_by_name(methods(), name, end);
  1369 int InstanceKlass::find_method_by_name(
  1370     Array<Method*>* methods, Symbol* name, int* end_ptr) {
  1371   assert(end_ptr != NULL, "just checking");
  1372   int start = binary_search(methods, name);
  1373   int end = start + 1;
  1374   if (start != -1) {
  1375     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
  1376     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
  1377     *end_ptr = end;
  1378     return start;
  1380   return -1;
  1383 Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
  1384   Klass* klass = const_cast<InstanceKlass*>(this);
  1385   while (klass != NULL) {
  1386     Method* method = InstanceKlass::cast(klass)->find_method(name, signature);
  1387     if (method != NULL) return method;
  1388     klass = InstanceKlass::cast(klass)->super();
  1390   return NULL;
  1393 // lookup a method in all the interfaces that this class implements
  1394 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
  1395                                                          Symbol* signature) const {
  1396   Array<Klass*>* all_ifs = transitive_interfaces();
  1397   int num_ifs = all_ifs->length();
  1398   InstanceKlass *ik = NULL;
  1399   for (int i = 0; i < num_ifs; i++) {
  1400     ik = InstanceKlass::cast(all_ifs->at(i));
  1401     Method* m = ik->lookup_method(name, signature);
  1402     if (m != NULL) {
  1403       return m;
  1406   return NULL;
  1409 /* jni_id_for_impl for jfieldIds only */
  1410 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
  1411   MutexLocker ml(JfieldIdCreation_lock);
  1412   // Retry lookup after we got the lock
  1413   JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
  1414   if (probe == NULL) {
  1415     // Slow case, allocate new static field identifier
  1416     probe = new JNIid(this_oop(), offset, this_oop->jni_ids());
  1417     this_oop->set_jni_ids(probe);
  1419   return probe;
  1423 /* jni_id_for for jfieldIds only */
  1424 JNIid* InstanceKlass::jni_id_for(int offset) {
  1425   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
  1426   if (probe == NULL) {
  1427     probe = jni_id_for_impl(this, offset);
  1429   return probe;
  1432 u2 InstanceKlass::enclosing_method_data(int offset) {
  1433   Array<jushort>* inner_class_list = inner_classes();
  1434   if (inner_class_list == NULL) {
  1435     return 0;
  1437   int length = inner_class_list->length();
  1438   if (length % inner_class_next_offset == 0) {
  1439     return 0;
  1440   } else {
  1441     int index = length - enclosing_method_attribute_size;
  1442     assert(offset < enclosing_method_attribute_size, "invalid offset");
  1443     return inner_class_list->at(index + offset);
  1447 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
  1448                                                  u2 method_index) {
  1449   Array<jushort>* inner_class_list = inner_classes();
  1450   assert (inner_class_list != NULL, "_inner_classes list is not set up");
  1451   int length = inner_class_list->length();
  1452   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
  1453     int index = length - enclosing_method_attribute_size;
  1454     inner_class_list->at_put(
  1455       index + enclosing_method_class_index_offset, class_index);
  1456     inner_class_list->at_put(
  1457       index + enclosing_method_method_index_offset, method_index);
  1461 // Lookup or create a jmethodID.
  1462 // This code is called by the VMThread and JavaThreads so the
  1463 // locking has to be done very carefully to avoid deadlocks
  1464 // and/or other cache consistency problems.
  1465 //
  1466 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
  1467   size_t idnum = (size_t)method_h->method_idnum();
  1468   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
  1469   size_t length = 0;
  1470   jmethodID id = NULL;
  1472   // We use a double-check locking idiom here because this cache is
  1473   // performance sensitive. In the normal system, this cache only
  1474   // transitions from NULL to non-NULL which is safe because we use
  1475   // release_set_methods_jmethod_ids() to advertise the new cache.
  1476   // A partially constructed cache should never be seen by a racing
  1477   // thread. We also use release_store_ptr() to save a new jmethodID
  1478   // in the cache so a partially constructed jmethodID should never be
  1479   // seen either. Cache reads of existing jmethodIDs proceed without a
  1480   // lock, but cache writes of a new jmethodID requires uniqueness and
  1481   // creation of the cache itself requires no leaks so a lock is
  1482   // generally acquired in those two cases.
  1483   //
  1484   // If the RedefineClasses() API has been used, then this cache can
  1485   // grow and we'll have transitions from non-NULL to bigger non-NULL.
  1486   // Cache creation requires no leaks and we require safety between all
  1487   // cache accesses and freeing of the old cache so a lock is generally
  1488   // acquired when the RedefineClasses() API has been used.
  1490   if (jmeths != NULL) {
  1491     // the cache already exists
  1492     if (!ik_h->idnum_can_increment()) {
  1493       // the cache can't grow so we can just get the current values
  1494       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1495     } else {
  1496       // cache can grow so we have to be more careful
  1497       if (Threads::number_of_threads() == 0 ||
  1498           SafepointSynchronize::is_at_safepoint()) {
  1499         // we're single threaded or at a safepoint - no locking needed
  1500         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1501       } else {
  1502         MutexLocker ml(JmethodIdCreation_lock);
  1503         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1507   // implied else:
  1508   // we need to allocate a cache so default length and id values are good
  1510   if (jmeths == NULL ||   // no cache yet
  1511       length <= idnum ||  // cache is too short
  1512       id == NULL) {       // cache doesn't contain entry
  1514     // This function can be called by the VMThread so we have to do all
  1515     // things that might block on a safepoint before grabbing the lock.
  1516     // Otherwise, we can deadlock with the VMThread or have a cache
  1517     // consistency issue. These vars keep track of what we might have
  1518     // to free after the lock is dropped.
  1519     jmethodID  to_dealloc_id     = NULL;
  1520     jmethodID* to_dealloc_jmeths = NULL;
  1522     // may not allocate new_jmeths or use it if we allocate it
  1523     jmethodID* new_jmeths = NULL;
  1524     if (length <= idnum) {
  1525       // allocate a new cache that might be used
  1526       size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
  1527       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
  1528       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
  1529       // cache size is stored in element[0], other elements offset by one
  1530       new_jmeths[0] = (jmethodID)size;
  1533     // allocate a new jmethodID that might be used
  1534     jmethodID new_id = NULL;
  1535     if (method_h->is_old() && !method_h->is_obsolete()) {
  1536       // The method passed in is old (but not obsolete), we need to use the current version
  1537       Method* current_method = ik_h->method_with_idnum((int)idnum);
  1538       assert(current_method != NULL, "old and but not obsolete, so should exist");
  1539       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
  1540     } else {
  1541       // It is the current version of the method or an obsolete method,
  1542       // use the version passed in
  1543       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
  1546     if (Threads::number_of_threads() == 0 ||
  1547         SafepointSynchronize::is_at_safepoint()) {
  1548       // we're single threaded or at a safepoint - no locking needed
  1549       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
  1550                                           &to_dealloc_id, &to_dealloc_jmeths);
  1551     } else {
  1552       MutexLocker ml(JmethodIdCreation_lock);
  1553       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
  1554                                           &to_dealloc_id, &to_dealloc_jmeths);
  1557     // The lock has been dropped so we can free resources.
  1558     // Free up either the old cache or the new cache if we allocated one.
  1559     if (to_dealloc_jmeths != NULL) {
  1560       FreeHeap(to_dealloc_jmeths);
  1562     // free up the new ID since it wasn't needed
  1563     if (to_dealloc_id != NULL) {
  1564       Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
  1567   return id;
  1571 // Common code to fetch the jmethodID from the cache or update the
  1572 // cache with the new jmethodID. This function should never do anything
  1573 // that causes the caller to go to a safepoint or we can deadlock with
  1574 // the VMThread or have cache consistency issues.
  1575 //
  1576 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
  1577             instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
  1578             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
  1579             jmethodID** to_dealloc_jmeths_p) {
  1580   assert(new_id != NULL, "sanity check");
  1581   assert(to_dealloc_id_p != NULL, "sanity check");
  1582   assert(to_dealloc_jmeths_p != NULL, "sanity check");
  1583   assert(Threads::number_of_threads() == 0 ||
  1584          SafepointSynchronize::is_at_safepoint() ||
  1585          JmethodIdCreation_lock->owned_by_self(), "sanity check");
  1587   // reacquire the cache - we are locked, single threaded or at a safepoint
  1588   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
  1589   jmethodID  id     = NULL;
  1590   size_t     length = 0;
  1592   if (jmeths == NULL ||                         // no cache yet
  1593       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
  1594     if (jmeths != NULL) {
  1595       // copy any existing entries from the old cache
  1596       for (size_t index = 0; index < length; index++) {
  1597         new_jmeths[index+1] = jmeths[index+1];
  1599       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
  1601     ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
  1602   } else {
  1603     // fetch jmethodID (if any) from the existing cache
  1604     id = jmeths[idnum+1];
  1605     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
  1607   if (id == NULL) {
  1608     // No matching jmethodID in the existing cache or we have a new
  1609     // cache or we just grew the cache. This cache write is done here
  1610     // by the first thread to win the foot race because a jmethodID
  1611     // needs to be unique once it is generally available.
  1612     id = new_id;
  1614     // The jmethodID cache can be read while unlocked so we have to
  1615     // make sure the new jmethodID is complete before installing it
  1616     // in the cache.
  1617     OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
  1618   } else {
  1619     *to_dealloc_id_p = new_id; // save new id for later delete
  1621   return id;
  1625 // Common code to get the jmethodID cache length and the jmethodID
  1626 // value at index idnum if there is one.
  1627 //
  1628 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
  1629        size_t idnum, size_t *length_p, jmethodID* id_p) {
  1630   assert(cache != NULL, "sanity check");
  1631   assert(length_p != NULL, "sanity check");
  1632   assert(id_p != NULL, "sanity check");
  1634   // cache size is stored in element[0], other elements offset by one
  1635   *length_p = (size_t)cache[0];
  1636   if (*length_p <= idnum) {  // cache is too short
  1637     *id_p = NULL;
  1638   } else {
  1639     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
  1644 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
  1645 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
  1646   size_t idnum = (size_t)method->method_idnum();
  1647   jmethodID* jmeths = methods_jmethod_ids_acquire();
  1648   size_t length;                                // length assigned as debugging crumb
  1649   jmethodID id = NULL;
  1650   if (jmeths != NULL &&                         // If there is a cache
  1651       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
  1652     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
  1654   return id;
  1658 // Cache an itable index
  1659 void InstanceKlass::set_cached_itable_index(size_t idnum, int index) {
  1660   int* indices = methods_cached_itable_indices_acquire();
  1661   int* to_dealloc_indices = NULL;
  1663   // We use a double-check locking idiom here because this cache is
  1664   // performance sensitive. In the normal system, this cache only
  1665   // transitions from NULL to non-NULL which is safe because we use
  1666   // release_set_methods_cached_itable_indices() to advertise the
  1667   // new cache. A partially constructed cache should never be seen
  1668   // by a racing thread. Cache reads and writes proceed without a
  1669   // lock, but creation of the cache itself requires no leaks so a
  1670   // lock is generally acquired in that case.
  1671   //
  1672   // If the RedefineClasses() API has been used, then this cache can
  1673   // grow and we'll have transitions from non-NULL to bigger non-NULL.
  1674   // Cache creation requires no leaks and we require safety between all
  1675   // cache accesses and freeing of the old cache so a lock is generally
  1676   // acquired when the RedefineClasses() API has been used.
  1678   if (indices == NULL || idnum_can_increment()) {
  1679     // we need a cache or the cache can grow
  1680     MutexLocker ml(JNICachedItableIndex_lock);
  1681     // reacquire the cache to see if another thread already did the work
  1682     indices = methods_cached_itable_indices_acquire();
  1683     size_t length = 0;
  1684     // cache size is stored in element[0], other elements offset by one
  1685     if (indices == NULL || (length = (size_t)indices[0]) <= idnum) {
  1686       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
  1687       int* new_indices = NEW_C_HEAP_ARRAY(int, size+1, mtClass);
  1688       new_indices[0] = (int)size;
  1689       // copy any existing entries
  1690       size_t i;
  1691       for (i = 0; i < length; i++) {
  1692         new_indices[i+1] = indices[i+1];
  1694       // Set all the rest to -1
  1695       for (i = length; i < size; i++) {
  1696         new_indices[i+1] = -1;
  1698       if (indices != NULL) {
  1699         // We have an old cache to delete so save it for after we
  1700         // drop the lock.
  1701         to_dealloc_indices = indices;
  1703       release_set_methods_cached_itable_indices(indices = new_indices);
  1706     if (idnum_can_increment()) {
  1707       // this cache can grow so we have to write to it safely
  1708       indices[idnum+1] = index;
  1710   } else {
  1711     CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
  1714   if (!idnum_can_increment()) {
  1715     // The cache cannot grow and this JNI itable index value does not
  1716     // have to be unique like a jmethodID. If there is a race to set it,
  1717     // it doesn't matter.
  1718     indices[idnum+1] = index;
  1721   if (to_dealloc_indices != NULL) {
  1722     // we allocated a new cache so free the old one
  1723     FreeHeap(to_dealloc_indices);
  1728 // Retrieve a cached itable index
  1729 int InstanceKlass::cached_itable_index(size_t idnum) {
  1730   int* indices = methods_cached_itable_indices_acquire();
  1731   if (indices != NULL && ((size_t)indices[0]) > idnum) {
  1732      // indices exist and are long enough, retrieve possible cached
  1733     return indices[idnum+1];
  1735   return -1;
  1739 //
  1740 // Walk the list of dependent nmethods searching for nmethods which
  1741 // are dependent on the changes that were passed in and mark them for
  1742 // deoptimization.  Returns the number of nmethods found.
  1743 //
  1744 int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
  1745   assert_locked_or_safepoint(CodeCache_lock);
  1746   int found = 0;
  1747   nmethodBucket* b = _dependencies;
  1748   while (b != NULL) {
  1749     nmethod* nm = b->get_nmethod();
  1750     // since dependencies aren't removed until an nmethod becomes a zombie,
  1751     // the dependency list may contain nmethods which aren't alive.
  1752     if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
  1753       if (TraceDependencies) {
  1754         ResourceMark rm;
  1755         tty->print_cr("Marked for deoptimization");
  1756         tty->print_cr("  context = %s", this->external_name());
  1757         changes.print();
  1758         nm->print();
  1759         nm->print_dependencies();
  1761       nm->mark_for_deoptimization();
  1762       found++;
  1764     b = b->next();
  1766   return found;
  1770 //
  1771 // Add an nmethodBucket to the list of dependencies for this nmethod.
  1772 // It's possible that an nmethod has multiple dependencies on this klass
  1773 // so a count is kept for each bucket to guarantee that creation and
  1774 // deletion of dependencies is consistent.
  1775 //
  1776 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
  1777   assert_locked_or_safepoint(CodeCache_lock);
  1778   nmethodBucket* b = _dependencies;
  1779   nmethodBucket* last = NULL;
  1780   while (b != NULL) {
  1781     if (nm == b->get_nmethod()) {
  1782       b->increment();
  1783       return;
  1785     b = b->next();
  1787   _dependencies = new nmethodBucket(nm, _dependencies);
  1791 //
  1792 // Decrement count of the nmethod in the dependency list and remove
  1793 // the bucket competely when the count goes to 0.  This method must
  1794 // find a corresponding bucket otherwise there's a bug in the
  1795 // recording of dependecies.
  1796 //
  1797 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
  1798   assert_locked_or_safepoint(CodeCache_lock);
  1799   nmethodBucket* b = _dependencies;
  1800   nmethodBucket* last = NULL;
  1801   while (b != NULL) {
  1802     if (nm == b->get_nmethod()) {
  1803       if (b->decrement() == 0) {
  1804         if (last == NULL) {
  1805           _dependencies = b->next();
  1806         } else {
  1807           last->set_next(b->next());
  1809         delete b;
  1811       return;
  1813     last = b;
  1814     b = b->next();
  1816 #ifdef ASSERT
  1817   tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
  1818   nm->print();
  1819 #endif // ASSERT
  1820   ShouldNotReachHere();
  1824 #ifndef PRODUCT
  1825 void InstanceKlass::print_dependent_nmethods(bool verbose) {
  1826   nmethodBucket* b = _dependencies;
  1827   int idx = 0;
  1828   while (b != NULL) {
  1829     nmethod* nm = b->get_nmethod();
  1830     tty->print("[%d] count=%d { ", idx++, b->count());
  1831     if (!verbose) {
  1832       nm->print_on(tty, "nmethod");
  1833       tty->print_cr(" } ");
  1834     } else {
  1835       nm->print();
  1836       nm->print_dependencies();
  1837       tty->print_cr("--- } ");
  1839     b = b->next();
  1844 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
  1845   nmethodBucket* b = _dependencies;
  1846   while (b != NULL) {
  1847     if (nm == b->get_nmethod()) {
  1848       return true;
  1850     b = b->next();
  1852   return false;
  1854 #endif //PRODUCT
  1857 // Garbage collection
  1859 void InstanceKlass::oops_do(OopClosure* cl) {
  1860   Klass::oops_do(cl);
  1862   cl->do_oop(adr_protection_domain());
  1863   cl->do_oop(adr_signers());
  1864   cl->do_oop(adr_init_lock());
  1866   // Don't walk the arrays since they are walked from the ClassLoaderData objects.
  1869 #ifdef ASSERT
  1870 template <class T> void assert_is_in(T *p) {
  1871   T heap_oop = oopDesc::load_heap_oop(p);
  1872   if (!oopDesc::is_null(heap_oop)) {
  1873     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1874     assert(Universe::heap()->is_in(o), "should be in heap");
  1877 template <class T> void assert_is_in_closed_subset(T *p) {
  1878   T heap_oop = oopDesc::load_heap_oop(p);
  1879   if (!oopDesc::is_null(heap_oop)) {
  1880     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1881     assert(Universe::heap()->is_in_closed_subset(o),
  1882            err_msg("should be in closed *p " INTPTR_FORMAT " " INTPTR_FORMAT, (address)p, (address)o));
  1885 template <class T> void assert_is_in_reserved(T *p) {
  1886   T heap_oop = oopDesc::load_heap_oop(p);
  1887   if (!oopDesc::is_null(heap_oop)) {
  1888     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1889     assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
  1892 template <class T> void assert_nothing(T *p) {}
  1894 #else
  1895 template <class T> void assert_is_in(T *p) {}
  1896 template <class T> void assert_is_in_closed_subset(T *p) {}
  1897 template <class T> void assert_is_in_reserved(T *p) {}
  1898 template <class T> void assert_nothing(T *p) {}
  1899 #endif // ASSERT
  1901 //
  1902 // Macros that iterate over areas of oops which are specialized on type of
  1903 // oop pointer either narrow or wide, depending on UseCompressedOops
  1904 //
  1905 // Parameters are:
  1906 //   T         - type of oop to point to (either oop or narrowOop)
  1907 //   start_p   - starting pointer for region to iterate over
  1908 //   count     - number of oops or narrowOops to iterate over
  1909 //   do_oop    - action to perform on each oop (it's arbitrary C code which
  1910 //               makes it more efficient to put in a macro rather than making
  1911 //               it a template function)
  1912 //   assert_fn - assert function which is template function because performance
  1913 //               doesn't matter when enabled.
  1914 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
  1915   T, start_p, count, do_oop,                \
  1916   assert_fn)                                \
  1917 {                                           \
  1918   T* p         = (T*)(start_p);             \
  1919   T* const end = p + (count);               \
  1920   while (p < end) {                         \
  1921     (assert_fn)(p);                         \
  1922     do_oop;                                 \
  1923     ++p;                                    \
  1924   }                                         \
  1927 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
  1928   T, start_p, count, do_oop,                \
  1929   assert_fn)                                \
  1930 {                                           \
  1931   T* const start = (T*)(start_p);           \
  1932   T*       p     = start + (count);         \
  1933   while (start < p) {                       \
  1934     --p;                                    \
  1935     (assert_fn)(p);                         \
  1936     do_oop;                                 \
  1937   }                                         \
  1940 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
  1941   T, start_p, count, low, high,             \
  1942   do_oop, assert_fn)                        \
  1943 {                                           \
  1944   T* const l = (T*)(low);                   \
  1945   T* const h = (T*)(high);                  \
  1946   assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
  1947          mask_bits((intptr_t)h, sizeof(T)-1) == 0,   \
  1948          "bounded region must be properly aligned"); \
  1949   T* p       = (T*)(start_p);               \
  1950   T* end     = p + (count);                 \
  1951   if (p < l) p = l;                         \
  1952   if (end > h) end = h;                     \
  1953   while (p < end) {                         \
  1954     (assert_fn)(p);                         \
  1955     do_oop;                                 \
  1956     ++p;                                    \
  1957   }                                         \
  1961 // The following macros call specialized macros, passing either oop or
  1962 // narrowOop as the specialization type.  These test the UseCompressedOops
  1963 // flag.
  1964 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn)            \
  1965 {                                                                        \
  1966   /* Compute oopmap block range. The common case                         \
  1967      is nonstatic_oop_map_size == 1. */                                  \
  1968   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  1969   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
  1970   if (UseCompressedOops) {                                               \
  1971     while (map < end_map) {                                              \
  1972       InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop,                   \
  1973         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  1974         do_oop, assert_fn)                                               \
  1975       ++map;                                                             \
  1976     }                                                                    \
  1977   } else {                                                               \
  1978     while (map < end_map) {                                              \
  1979       InstanceKlass_SPECIALIZED_OOP_ITERATE(oop,                         \
  1980         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  1981         do_oop, assert_fn)                                               \
  1982       ++map;                                                             \
  1983     }                                                                    \
  1984   }                                                                      \
  1987 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn)    \
  1988 {                                                                        \
  1989   OopMapBlock* const start_map = start_of_nonstatic_oop_maps();          \
  1990   OopMapBlock* map             = start_map + nonstatic_oop_map_count();  \
  1991   if (UseCompressedOops) {                                               \
  1992     while (start_map < map) {                                            \
  1993       --map;                                                             \
  1994       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop,           \
  1995         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  1996         do_oop, assert_fn)                                               \
  1997     }                                                                    \
  1998   } else {                                                               \
  1999     while (start_map < map) {                                            \
  2000       --map;                                                             \
  2001       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop,                 \
  2002         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  2003         do_oop, assert_fn)                                               \
  2004     }                                                                    \
  2005   }                                                                      \
  2008 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop,    \
  2009                                               assert_fn)                 \
  2010 {                                                                        \
  2011   /* Compute oopmap block range. The common case is                      \
  2012      nonstatic_oop_map_size == 1, so we accept the                       \
  2013      usually non-existent extra overhead of examining                    \
  2014      all the maps. */                                                    \
  2015   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  2016   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
  2017   if (UseCompressedOops) {                                               \
  2018     while (map < end_map) {                                              \
  2019       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop,           \
  2020         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  2021         low, high,                                                       \
  2022         do_oop, assert_fn)                                               \
  2023       ++map;                                                             \
  2024     }                                                                    \
  2025   } else {                                                               \
  2026     while (map < end_map) {                                              \
  2027       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop,                 \
  2028         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  2029         low, high,                                                       \
  2030         do_oop, assert_fn)                                               \
  2031       ++map;                                                             \
  2032     }                                                                    \
  2033   }                                                                      \
  2036 void InstanceKlass::oop_follow_contents(oop obj) {
  2037   assert(obj != NULL, "can't follow the content of NULL object");
  2038   MarkSweep::follow_klass(obj->klass());
  2039   InstanceKlass_OOP_MAP_ITERATE( \
  2040     obj, \
  2041     MarkSweep::mark_and_push(p), \
  2042     assert_is_in_closed_subset)
  2045 #ifndef SERIALGC
  2046 void InstanceKlass::oop_follow_contents(ParCompactionManager* cm,
  2047                                         oop obj) {
  2048   assert(obj != NULL, "can't follow the content of NULL object");
  2049   PSParallelCompact::follow_klass(cm, obj->klass());
  2050   // Only mark the header and let the scan of the meta-data mark
  2051   // everything else.
  2052   InstanceKlass_OOP_MAP_ITERATE( \
  2053     obj, \
  2054     PSParallelCompact::mark_and_push(cm, p), \
  2055     assert_is_in)
  2057 #endif // SERIALGC
  2059 // closure's do_metadata() method dictates whether the given closure should be
  2060 // applied to the klass ptr in the object header.
  2062 #define if_do_metadata_checked(closure, nv_suffix)                    \
  2063   /* Make sure the non-virtual and the virtual versions match. */     \
  2064   assert(closure->do_metadata##nv_suffix() == closure->do_metadata(), \
  2065       "Inconsistency in do_metadata");                                \
  2066   if (closure->do_metadata##nv_suffix())
  2068 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)        \
  2070 int InstanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
  2071   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  2072   /* header */                                                          \
  2073   if_do_metadata_checked(closure, nv_suffix) {                          \
  2074     closure->do_klass##nv_suffix(obj->klass());                         \
  2075   }                                                                     \
  2076   InstanceKlass_OOP_MAP_ITERATE(                                        \
  2077     obj,                                                                \
  2078     SpecializationStats::                                               \
  2079       record_do_oop_call##nv_suffix(SpecializationStats::ik);           \
  2080     (closure)->do_oop##nv_suffix(p),                                    \
  2081     assert_is_in_closed_subset)                                         \
  2082   return size_helper();                                                 \
  2085 #ifndef SERIALGC
  2086 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
  2088 int InstanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj,                \
  2089                                               OopClosureType* closure) {        \
  2090   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
  2091   /* header */                                                                  \
  2092   if_do_metadata_checked(closure, nv_suffix) {                                  \
  2093     closure->do_klass##nv_suffix(obj->klass());                                 \
  2094   }                                                                             \
  2095   /* instance variables */                                                      \
  2096   InstanceKlass_OOP_MAP_REVERSE_ITERATE(                                        \
  2097     obj,                                                                        \
  2098     SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
  2099     (closure)->do_oop##nv_suffix(p),                                            \
  2100     assert_is_in_closed_subset)                                                 \
  2101    return size_helper();                                                        \
  2103 #endif // !SERIALGC
  2105 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
  2107 int InstanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj,              \
  2108                                                   OopClosureType* closure, \
  2109                                                   MemRegion mr) {          \
  2110   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  2111   if_do_metadata_checked(closure, nv_suffix) {                           \
  2112     if (mr.contains(obj)) {                                              \
  2113       closure->do_klass##nv_suffix(obj->klass());                        \
  2114     }                                                                    \
  2115   }                                                                      \
  2116   InstanceKlass_BOUNDED_OOP_MAP_ITERATE(                                 \
  2117     obj, mr.start(), mr.end(),                                           \
  2118     (closure)->do_oop##nv_suffix(p),                                     \
  2119     assert_is_in_closed_subset)                                          \
  2120   return size_helper();                                                  \
  2123 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
  2124 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
  2125 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
  2126 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
  2127 #ifndef SERIALGC
  2128 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
  2129 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
  2130 #endif // !SERIALGC
  2132 int InstanceKlass::oop_adjust_pointers(oop obj) {
  2133   int size = size_helper();
  2134   InstanceKlass_OOP_MAP_ITERATE( \
  2135     obj, \
  2136     MarkSweep::adjust_pointer(p), \
  2137     assert_is_in)
  2138   MarkSweep::adjust_klass(obj->klass());
  2139   return size;
  2142 #ifndef SERIALGC
  2143 void InstanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
  2144   InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
  2145     obj, \
  2146     if (PSScavenge::should_scavenge(p)) { \
  2147       pm->claim_or_forward_depth(p); \
  2148     }, \
  2149     assert_nothing )
  2152 int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
  2153   int size = size_helper();
  2154   InstanceKlass_OOP_MAP_ITERATE( \
  2155     obj, \
  2156     PSParallelCompact::adjust_pointer(p), \
  2157     assert_is_in)
  2158   obj->update_header(cm);
  2159   return size;
  2162 #endif // SERIALGC
  2164 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
  2165   assert(is_loader_alive(is_alive), "this klass should be live");
  2166   if (is_interface()) {
  2167     if (ClassUnloading) {
  2168       Klass* impl = implementor();
  2169       if (impl != NULL) {
  2170         if (!impl->is_loader_alive(is_alive)) {
  2171           // remove this guy
  2172           *adr_implementor() = NULL;
  2179 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
  2180 #ifdef COMPILER2
  2181   // Currently only used by C2.
  2182   for (int m = 0; m < methods()->length(); m++) {
  2183     MethodData* mdo = methods()->at(m)->method_data();
  2184     if (mdo != NULL) {
  2185       for (ProfileData* data = mdo->first_data();
  2186            mdo->is_valid(data);
  2187            data = mdo->next_data(data)) {
  2188         data->clean_weak_klass_links(is_alive);
  2192 #else
  2193 #ifdef ASSERT
  2194   // Verify that we haven't started to use MDOs for C1.
  2195   for (int m = 0; m < methods()->length(); m++) {
  2196     MethodData* mdo = methods()->at(m)->method_data();
  2197     assert(mdo == NULL, "Didn't expect C1 to use MDOs");
  2199 #endif // ASSERT
  2200 #endif // !COMPILER2
  2204 static void remove_unshareable_in_class(Klass* k) {
  2205   // remove klass's unshareable info
  2206   k->remove_unshareable_info();
  2209 void InstanceKlass::remove_unshareable_info() {
  2210   Klass::remove_unshareable_info();
  2211   // Unlink the class
  2212   if (is_linked()) {
  2213     unlink_class();
  2215   init_implementor();
  2217   constants()->remove_unshareable_info();
  2219   for (int i = 0; i < methods()->length(); i++) {
  2220     Method* m = methods()->at(i);
  2221     m->remove_unshareable_info();
  2224   // Need to reinstate when reading back the class.
  2225   set_init_lock(NULL);
  2227   // do array classes also.
  2228   array_klasses_do(remove_unshareable_in_class);
  2231 void restore_unshareable_in_class(Klass* k, TRAPS) {
  2232   k->restore_unshareable_info(CHECK);
  2235 void InstanceKlass::restore_unshareable_info(TRAPS) {
  2236   Klass::restore_unshareable_info(CHECK);
  2237   instanceKlassHandle ik(THREAD, this);
  2239   Array<Method*>* methods = ik->methods();
  2240   int num_methods = methods->length();
  2241   for (int index2 = 0; index2 < num_methods; ++index2) {
  2242     methodHandle m(THREAD, methods->at(index2));
  2243     m()->link_method(m, CHECK);
  2244     // restore method's vtable by calling a virtual function
  2245     m->restore_vtable();
  2247   if (JvmtiExport::has_redefined_a_class()) {
  2248     // Reinitialize vtable because RedefineClasses may have changed some
  2249     // entries in this vtable for super classes so the CDS vtable might
  2250     // point to old or obsolete entries.  RedefineClasses doesn't fix up
  2251     // vtables in the shared system dictionary, only the main one.
  2252     // It also redefines the itable too so fix that too.
  2253     ResourceMark rm(THREAD);
  2254     ik->vtable()->initialize_vtable(false, CHECK);
  2255     ik->itable()->initialize_itable(false, CHECK);
  2258   // Allocate a simple java object for a lock.
  2259   // This needs to be a java object because during class initialization
  2260   // it can be held across a java call.
  2261   typeArrayOop r = oopFactory::new_typeArray(T_INT, 0, CHECK);
  2262   Handle h(THREAD, (oop)r);
  2263   ik->set_init_lock(h());
  2265   // restore constant pool resolved references
  2266   ik->constants()->restore_unshareable_info(CHECK);
  2268   ik->array_klasses_do(restore_unshareable_in_class, CHECK);
  2271 static void clear_all_breakpoints(Method* m) {
  2272   m->clear_all_breakpoints();
  2275 void InstanceKlass::release_C_heap_structures() {
  2276   // Deallocate oop map cache
  2277   if (_oop_map_cache != NULL) {
  2278     delete _oop_map_cache;
  2279     _oop_map_cache = NULL;
  2282   // Deallocate JNI identifiers for jfieldIDs
  2283   JNIid::deallocate(jni_ids());
  2284   set_jni_ids(NULL);
  2286   jmethodID* jmeths = methods_jmethod_ids_acquire();
  2287   if (jmeths != (jmethodID*)NULL) {
  2288     release_set_methods_jmethod_ids(NULL);
  2289     FreeHeap(jmeths);
  2292   int* indices = methods_cached_itable_indices_acquire();
  2293   if (indices != (int*)NULL) {
  2294     release_set_methods_cached_itable_indices(NULL);
  2295     FreeHeap(indices);
  2298   // release dependencies
  2299   nmethodBucket* b = _dependencies;
  2300   _dependencies = NULL;
  2301   while (b != NULL) {
  2302     nmethodBucket* next = b->next();
  2303     delete b;
  2304     b = next;
  2307   // Deallocate breakpoint records
  2308   if (breakpoints() != 0x0) {
  2309     methods_do(clear_all_breakpoints);
  2310     assert(breakpoints() == 0x0, "should have cleared breakpoints");
  2313   // deallocate information about previous versions
  2314   if (_previous_versions != NULL) {
  2315     for (int i = _previous_versions->length() - 1; i >= 0; i--) {
  2316       PreviousVersionNode * pv_node = _previous_versions->at(i);
  2317       delete pv_node;
  2319     delete _previous_versions;
  2320     _previous_versions = NULL;
  2323   // deallocate the cached class file
  2324   if (_cached_class_file_bytes != NULL) {
  2325     os::free(_cached_class_file_bytes, mtClass);
  2326     _cached_class_file_bytes = NULL;
  2327     _cached_class_file_len = 0;
  2330   // Decrement symbol reference counts associated with the unloaded class.
  2331   if (_name != NULL) _name->decrement_refcount();
  2332   // unreference array name derived from this class name (arrays of an unloaded
  2333   // class can't be referenced anymore).
  2334   if (_array_name != NULL)  _array_name->decrement_refcount();
  2335   if (_source_file_name != NULL) _source_file_name->decrement_refcount();
  2336   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension, mtClass);
  2338   assert(_total_instanceKlass_count >= 1, "Sanity check");
  2339   Atomic::dec(&_total_instanceKlass_count);
  2342 void InstanceKlass::set_source_file_name(Symbol* n) {
  2343   _source_file_name = n;
  2344   if (_source_file_name != NULL) _source_file_name->increment_refcount();
  2347 void InstanceKlass::set_source_debug_extension(char* array, int length) {
  2348   if (array == NULL) {
  2349     _source_debug_extension = NULL;
  2350   } else {
  2351     // Adding one to the attribute length in order to store a null terminator
  2352     // character could cause an overflow because the attribute length is
  2353     // already coded with an u4 in the classfile, but in practice, it's
  2354     // unlikely to happen.
  2355     assert((length+1) > length, "Overflow checking");
  2356     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
  2357     for (int i = 0; i < length; i++) {
  2358       sde[i] = array[i];
  2360     sde[length] = '\0';
  2361     _source_debug_extension = sde;
  2365 address InstanceKlass::static_field_addr(int offset) {
  2366   return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + (intptr_t)java_mirror());
  2370 const char* InstanceKlass::signature_name() const {
  2371   const char* src = (const char*) (name()->as_C_string());
  2372   const int src_length = (int)strlen(src);
  2373   char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
  2374   int src_index = 0;
  2375   int dest_index = 0;
  2376   dest[dest_index++] = 'L';
  2377   while (src_index < src_length) {
  2378     dest[dest_index++] = src[src_index++];
  2380   dest[dest_index++] = ';';
  2381   dest[dest_index] = '\0';
  2382   return dest;
  2385 // different verisons of is_same_class_package
  2386 bool InstanceKlass::is_same_class_package(Klass* class2) {
  2387   Klass* class1 = this;
  2388   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
  2389   Symbol* classname1 = class1->name();
  2391   if (class2->oop_is_objArray()) {
  2392     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
  2394   oop classloader2;
  2395   if (class2->oop_is_instance()) {
  2396     classloader2 = InstanceKlass::cast(class2)->class_loader();
  2397   } else {
  2398     assert(class2->oop_is_typeArray(), "should be type array");
  2399     classloader2 = NULL;
  2401   Symbol* classname2 = class2->name();
  2403   return InstanceKlass::is_same_class_package(classloader1, classname1,
  2404                                               classloader2, classname2);
  2407 bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
  2408   Klass* class1 = this;
  2409   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
  2410   Symbol* classname1 = class1->name();
  2412   return InstanceKlass::is_same_class_package(classloader1, classname1,
  2413                                               classloader2, classname2);
  2416 // return true if two classes are in the same package, classloader
  2417 // and classname information is enough to determine a class's package
  2418 bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
  2419                                           oop class_loader2, Symbol* class_name2) {
  2420   if (class_loader1 != class_loader2) {
  2421     return false;
  2422   } else if (class_name1 == class_name2) {
  2423     return true;                // skip painful bytewise comparison
  2424   } else {
  2425     ResourceMark rm;
  2427     // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
  2428     // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
  2429     // Otherwise, we just compare jbyte values between the strings.
  2430     const jbyte *name1 = class_name1->base();
  2431     const jbyte *name2 = class_name2->base();
  2433     const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
  2434     const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
  2436     if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
  2437       // One of the two doesn't have a package.  Only return true
  2438       // if the other one also doesn't have a package.
  2439       return last_slash1 == last_slash2;
  2440     } else {
  2441       // Skip over '['s
  2442       if (*name1 == '[') {
  2443         do {
  2444           name1++;
  2445         } while (*name1 == '[');
  2446         if (*name1 != 'L') {
  2447           // Something is terribly wrong.  Shouldn't be here.
  2448           return false;
  2451       if (*name2 == '[') {
  2452         do {
  2453           name2++;
  2454         } while (*name2 == '[');
  2455         if (*name2 != 'L') {
  2456           // Something is terribly wrong.  Shouldn't be here.
  2457           return false;
  2461       // Check that package part is identical
  2462       int length1 = last_slash1 - name1;
  2463       int length2 = last_slash2 - name2;
  2465       return UTF8::equal(name1, length1, name2, length2);
  2470 // Returns true iff super_method can be overridden by a method in targetclassname
  2471 // See JSL 3rd edition 8.4.6.1
  2472 // Assumes name-signature match
  2473 // "this" is InstanceKlass of super_method which must exist
  2474 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
  2475 bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
  2476    // Private methods can not be overridden
  2477    if (super_method->is_private()) {
  2478      return false;
  2480    // If super method is accessible, then override
  2481    if ((super_method->is_protected()) ||
  2482        (super_method->is_public())) {
  2483      return true;
  2485    // Package-private methods are not inherited outside of package
  2486    assert(super_method->is_package_private(), "must be package private");
  2487    return(is_same_class_package(targetclassloader(), targetclassname));
  2490 /* defined for now in jvm.cpp, for historical reasons *--
  2491 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
  2492                                                      Symbol*& simple_name_result, TRAPS) {
  2493   ...
  2495 */
  2497 // tell if two classes have the same enclosing class (at package level)
  2498 bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
  2499                                                 Klass* class2_oop, TRAPS) {
  2500   if (class2_oop == class1())                       return true;
  2501   if (!class2_oop->oop_is_instance())  return false;
  2502   instanceKlassHandle class2(THREAD, class2_oop);
  2504   // must be in same package before we try anything else
  2505   if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
  2506     return false;
  2508   // As long as there is an outer1.getEnclosingClass,
  2509   // shift the search outward.
  2510   instanceKlassHandle outer1 = class1;
  2511   for (;;) {
  2512     // As we walk along, look for equalities between outer1 and class2.
  2513     // Eventually, the walks will terminate as outer1 stops
  2514     // at the top-level class around the original class.
  2515     bool ignore_inner_is_member;
  2516     Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
  2517                                                     CHECK_false);
  2518     if (next == NULL)  break;
  2519     if (next == class2())  return true;
  2520     outer1 = instanceKlassHandle(THREAD, next);
  2523   // Now do the same for class2.
  2524   instanceKlassHandle outer2 = class2;
  2525   for (;;) {
  2526     bool ignore_inner_is_member;
  2527     Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
  2528                                                     CHECK_false);
  2529     if (next == NULL)  break;
  2530     // Might as well check the new outer against all available values.
  2531     if (next == class1())  return true;
  2532     if (next == outer1())  return true;
  2533     outer2 = instanceKlassHandle(THREAD, next);
  2536   // If by this point we have not found an equality between the
  2537   // two classes, we know they are in separate package members.
  2538   return false;
  2542 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
  2543   jint access = access_flags().as_int();
  2545   // But check if it happens to be member class.
  2546   instanceKlassHandle ik(THREAD, this);
  2547   InnerClassesIterator iter(ik);
  2548   for (; !iter.done(); iter.next()) {
  2549     int ioff = iter.inner_class_info_index();
  2550     // Inner class attribute can be zero, skip it.
  2551     // Strange but true:  JVM spec. allows null inner class refs.
  2552     if (ioff == 0) continue;
  2554     // only look at classes that are already loaded
  2555     // since we are looking for the flags for our self.
  2556     Symbol* inner_name = ik->constants()->klass_name_at(ioff);
  2557     if ((ik->name() == inner_name)) {
  2558       // This is really a member class.
  2559       access = iter.inner_access_flags();
  2560       break;
  2563   // Remember to strip ACC_SUPER bit
  2564   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
  2567 jint InstanceKlass::jvmti_class_status() const {
  2568   jint result = 0;
  2570   if (is_linked()) {
  2571     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
  2574   if (is_initialized()) {
  2575     assert(is_linked(), "Class status is not consistent");
  2576     result |= JVMTI_CLASS_STATUS_INITIALIZED;
  2578   if (is_in_error_state()) {
  2579     result |= JVMTI_CLASS_STATUS_ERROR;
  2581   return result;
  2584 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
  2585   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
  2586   int method_table_offset_in_words = ioe->offset()/wordSize;
  2587   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
  2588                        / itableOffsetEntry::size();
  2590   for (int cnt = 0 ; ; cnt ++, ioe ++) {
  2591     // If the interface isn't implemented by the receiver class,
  2592     // the VM should throw IncompatibleClassChangeError.
  2593     if (cnt >= nof_interfaces) {
  2594       THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
  2597     Klass* ik = ioe->interface_klass();
  2598     if (ik == holder) break;
  2601   itableMethodEntry* ime = ioe->first_method_entry(this);
  2602   Method* m = ime[index].method();
  2603   if (m == NULL) {
  2604     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
  2606   return m;
  2609 // On-stack replacement stuff
  2610 void InstanceKlass::add_osr_nmethod(nmethod* n) {
  2611   // only one compilation can be active
  2612   NEEDS_CLEANUP
  2613   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2614   OsrList_lock->lock_without_safepoint_check();
  2615   assert(n->is_osr_method(), "wrong kind of nmethod");
  2616   n->set_osr_link(osr_nmethods_head());
  2617   set_osr_nmethods_head(n);
  2618   // Raise the highest osr level if necessary
  2619   if (TieredCompilation) {
  2620     Method* m = n->method();
  2621     m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
  2623   // Remember to unlock again
  2624   OsrList_lock->unlock();
  2626   // Get rid of the osr methods for the same bci that have lower levels.
  2627   if (TieredCompilation) {
  2628     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
  2629       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
  2630       if (inv != NULL && inv->is_in_use()) {
  2631         inv->make_not_entrant();
  2638 void InstanceKlass::remove_osr_nmethod(nmethod* n) {
  2639   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2640   OsrList_lock->lock_without_safepoint_check();
  2641   assert(n->is_osr_method(), "wrong kind of nmethod");
  2642   nmethod* last = NULL;
  2643   nmethod* cur  = osr_nmethods_head();
  2644   int max_level = CompLevel_none;  // Find the max comp level excluding n
  2645   Method* m = n->method();
  2646   // Search for match
  2647   while(cur != NULL && cur != n) {
  2648     if (TieredCompilation) {
  2649       // Find max level before n
  2650       max_level = MAX2(max_level, cur->comp_level());
  2652     last = cur;
  2653     cur = cur->osr_link();
  2655   nmethod* next = NULL;
  2656   if (cur == n) {
  2657     next = cur->osr_link();
  2658     if (last == NULL) {
  2659       // Remove first element
  2660       set_osr_nmethods_head(next);
  2661     } else {
  2662       last->set_osr_link(next);
  2665   n->set_osr_link(NULL);
  2666   if (TieredCompilation) {
  2667     cur = next;
  2668     while (cur != NULL) {
  2669       // Find max level after n
  2670       max_level = MAX2(max_level, cur->comp_level());
  2671       cur = cur->osr_link();
  2673     m->set_highest_osr_comp_level(max_level);
  2675   // Remember to unlock again
  2676   OsrList_lock->unlock();
  2679 nmethod* InstanceKlass::lookup_osr_nmethod(Method* const m, int bci, int comp_level, bool match_level) const {
  2680   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2681   OsrList_lock->lock_without_safepoint_check();
  2682   nmethod* osr = osr_nmethods_head();
  2683   nmethod* best = NULL;
  2684   while (osr != NULL) {
  2685     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
  2686     // There can be a time when a c1 osr method exists but we are waiting
  2687     // for a c2 version. When c2 completes its osr nmethod we will trash
  2688     // the c1 version and only be able to find the c2 version. However
  2689     // while we overflow in the c1 code at back branches we don't want to
  2690     // try and switch to the same code as we are already running
  2692     if (osr->method() == m &&
  2693         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
  2694       if (match_level) {
  2695         if (osr->comp_level() == comp_level) {
  2696           // Found a match - return it.
  2697           OsrList_lock->unlock();
  2698           return osr;
  2700       } else {
  2701         if (best == NULL || (osr->comp_level() > best->comp_level())) {
  2702           if (osr->comp_level() == CompLevel_highest_tier) {
  2703             // Found the best possible - return it.
  2704             OsrList_lock->unlock();
  2705             return osr;
  2707           best = osr;
  2711     osr = osr->osr_link();
  2713   OsrList_lock->unlock();
  2714   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
  2715     return best;
  2717   return NULL;
  2720 // -----------------------------------------------------------------------------------------------------
  2721 // Printing
  2723 #ifndef PRODUCT
  2725 #define BULLET  " - "
  2727 static const char* state_names[] = {
  2728   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
  2729 };
  2731 void InstanceKlass::print_on(outputStream* st) const {
  2732   assert(is_klass(), "must be klass");
  2733   Klass::print_on(st);
  2735   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
  2736   st->print(BULLET"klass size:        %d", size());                               st->cr();
  2737   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
  2738   st->print(BULLET"state:             "); st->print_cr(state_names[_init_state]);
  2739   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
  2740   st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
  2741   st->print(BULLET"sub:               ");
  2742   Klass* sub = subklass();
  2743   int n;
  2744   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
  2745     if (n < MaxSubklassPrintSize) {
  2746       sub->print_value_on(st);
  2747       st->print("   ");
  2750   if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
  2751   st->cr();
  2753   if (is_interface()) {
  2754     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
  2755     if (nof_implementors() == 1) {
  2756       st->print_cr(BULLET"implementor:    ");
  2757       st->print("   ");
  2758       implementor()->print_value_on(st);
  2759       st->cr();
  2763   st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
  2764   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
  2765   if (Verbose) {
  2766     Array<Method*>* method_array = methods();
  2767     for(int i = 0; i < method_array->length(); i++) {
  2768       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
  2771   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);       st->cr();
  2772   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
  2773   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
  2774   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
  2775   if (class_loader_data() != NULL) {
  2776     st->print(BULLET"class loader data:  ");
  2777     class_loader_data()->print_value_on(st);
  2778     st->cr();
  2780   st->print(BULLET"protection domain: "); ((InstanceKlass*)this)->protection_domain()->print_value_on(st); st->cr();
  2781   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
  2782   st->print(BULLET"signers:           "); signers()->print_value_on(st);               st->cr();
  2783   st->print(BULLET"init_lock:         "); ((oop)init_lock())->print_value_on(st);             st->cr();
  2784   if (source_file_name() != NULL) {
  2785     st->print(BULLET"source file:       ");
  2786     source_file_name()->print_value_on(st);
  2787     st->cr();
  2789   if (source_debug_extension() != NULL) {
  2790     st->print(BULLET"source debug extension:       ");
  2791     st->print("%s", source_debug_extension());
  2792     st->cr();
  2794   st->print(BULLET"annotations:       "); annotations()->print_value_on(st); st->cr();
  2796     ResourceMark rm;
  2797     // PreviousVersionInfo objects returned via PreviousVersionWalker
  2798     // contain a GrowableArray of handles. We have to clean up the
  2799     // GrowableArray _after_ the PreviousVersionWalker destructor
  2800     // has destroyed the handles.
  2802       bool have_pv = false;
  2803       PreviousVersionWalker pvw((InstanceKlass*)this);
  2804       for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
  2805            pv_info != NULL; pv_info = pvw.next_previous_version()) {
  2806         if (!have_pv)
  2807           st->print(BULLET"previous version:  ");
  2808         have_pv = true;
  2809         pv_info->prev_constant_pool_handle()()->print_value_on(st);
  2811       if (have_pv)  st->cr();
  2812     } // pvw is cleaned up
  2813   } // rm is cleaned up
  2815   if (generic_signature() != NULL) {
  2816     st->print(BULLET"generic signature: ");
  2817     generic_signature()->print_value_on(st);
  2818     st->cr();
  2820   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
  2821   st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
  2822   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable());  st->cr();
  2823   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
  2824   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
  2825   FieldPrinter print_static_field(st);
  2826   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
  2827   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
  2828   FieldPrinter print_nonstatic_field(st);
  2829   ((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);
  2831   st->print(BULLET"non-static oop maps: ");
  2832   OopMapBlock* map     = start_of_nonstatic_oop_maps();
  2833   OopMapBlock* end_map = map + nonstatic_oop_map_count();
  2834   while (map < end_map) {
  2835     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
  2836     map++;
  2838   st->cr();
  2841 #endif //PRODUCT
  2843 void InstanceKlass::print_value_on(outputStream* st) const {
  2844   assert(is_klass(), "must be klass");
  2845   name()->print_value_on(st);
  2848 #ifndef PRODUCT
  2850 void FieldPrinter::do_field(fieldDescriptor* fd) {
  2851   _st->print(BULLET);
  2852    if (_obj == NULL) {
  2853      fd->print_on(_st);
  2854      _st->cr();
  2855    } else {
  2856      fd->print_on_for(_st, _obj);
  2857      _st->cr();
  2862 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
  2863   Klass::oop_print_on(obj, st);
  2865   if (this == SystemDictionary::String_klass()) {
  2866     typeArrayOop value  = java_lang_String::value(obj);
  2867     juint        offset = java_lang_String::offset(obj);
  2868     juint        length = java_lang_String::length(obj);
  2869     if (value != NULL &&
  2870         value->is_typeArray() &&
  2871         offset          <= (juint) value->length() &&
  2872         offset + length <= (juint) value->length()) {
  2873       st->print(BULLET"string: ");
  2874       Handle h_obj(obj);
  2875       java_lang_String::print(h_obj, st);
  2876       st->cr();
  2877       if (!WizardMode)  return;  // that is enough
  2881   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
  2882   FieldPrinter print_field(st, obj);
  2883   do_nonstatic_fields(&print_field);
  2885   if (this == SystemDictionary::Class_klass()) {
  2886     st->print(BULLET"signature: ");
  2887     java_lang_Class::print_signature(obj, st);
  2888     st->cr();
  2889     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
  2890     st->print(BULLET"fake entry for mirror: ");
  2891     mirrored_klass->print_value_on_maybe_null(st);
  2892     st->cr();
  2893     st->print(BULLET"fake entry resolved_constructor: ");
  2894     Method* ctor = java_lang_Class::resolved_constructor(obj);
  2895     ctor->print_value_on_maybe_null(st);
  2896     Klass* array_klass = java_lang_Class::array_klass(obj);
  2897     st->cr();
  2898     st->print(BULLET"fake entry for array: ");
  2899     array_klass->print_value_on_maybe_null(st);
  2900     st->cr();
  2901     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
  2902     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
  2903     Klass* real_klass = java_lang_Class::as_Klass(obj);
  2904     if (real_klass != NULL && real_klass->oop_is_instance()) {
  2905       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
  2907   } else if (this == SystemDictionary::MethodType_klass()) {
  2908     st->print(BULLET"signature: ");
  2909     java_lang_invoke_MethodType::print_signature(obj, st);
  2910     st->cr();
  2914 #endif //PRODUCT
  2916 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
  2917   st->print("a ");
  2918   name()->print_value_on(st);
  2919   obj->print_address_on(st);
  2920   if (this == SystemDictionary::String_klass()
  2921       && java_lang_String::value(obj) != NULL) {
  2922     ResourceMark rm;
  2923     int len = java_lang_String::length(obj);
  2924     int plen = (len < 24 ? len : 12);
  2925     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
  2926     st->print(" = \"%s\"", str);
  2927     if (len > plen)
  2928       st->print("...[%d]", len);
  2929   } else if (this == SystemDictionary::Class_klass()) {
  2930     Klass* k = java_lang_Class::as_Klass(obj);
  2931     st->print(" = ");
  2932     if (k != NULL) {
  2933       k->print_value_on(st);
  2934     } else {
  2935       const char* tname = type2name(java_lang_Class::primitive_type(obj));
  2936       st->print("%s", tname ? tname : "type?");
  2938   } else if (this == SystemDictionary::MethodType_klass()) {
  2939     st->print(" = ");
  2940     java_lang_invoke_MethodType::print_signature(obj, st);
  2941   } else if (java_lang_boxing_object::is_instance(obj)) {
  2942     st->print(" = ");
  2943     java_lang_boxing_object::print(obj, st);
  2944   } else if (this == SystemDictionary::LambdaForm_klass()) {
  2945     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
  2946     if (vmentry != NULL) {
  2947       st->print(" => ");
  2948       vmentry->print_value_on(st);
  2950   } else if (this == SystemDictionary::MemberName_klass()) {
  2951     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
  2952     if (vmtarget != NULL) {
  2953       st->print(" = ");
  2954       vmtarget->print_value_on(st);
  2955     } else {
  2956       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
  2957       st->print(".");
  2958       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
  2963 const char* InstanceKlass::internal_name() const {
  2964   return external_name();
  2967 // Verification
  2969 class VerifyFieldClosure: public OopClosure {
  2970  protected:
  2971   template <class T> void do_oop_work(T* p) {
  2972     oop obj = oopDesc::load_decode_heap_oop(p);
  2973     if (!obj->is_oop_or_null()) {
  2974       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
  2975       Universe::print();
  2976       guarantee(false, "boom");
  2979  public:
  2980   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
  2981   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
  2982 };
  2984 void InstanceKlass::verify_on(outputStream* st) {
  2985   Klass::verify_on(st);
  2986   Thread *thread = Thread::current();
  2988 #ifndef PRODUCT
  2989   // Avoid redundant verifies
  2990   if (_verify_count == Universe::verify_count()) return;
  2991   _verify_count = Universe::verify_count();
  2992 #endif
  2993   // Verify that klass is present in SystemDictionary
  2994   if (is_loaded() && !is_anonymous()) {
  2995     Symbol* h_name = name();
  2996     SystemDictionary::verify_obj_klass_present(h_name, class_loader_data());
  2999   // Verify static fields
  3000   VerifyFieldClosure blk;
  3002   // Verify vtables
  3003   if (is_linked()) {
  3004     ResourceMark rm(thread);
  3005     // $$$ This used to be done only for m/s collections.  Doing it
  3006     // always seemed a valid generalization.  (DLD -- 6/00)
  3007     vtable()->verify(st);
  3010   // Verify first subklass
  3011   if (subklass_oop() != NULL) {
  3012     guarantee(subklass_oop()->is_metadata(), "should be in metaspace");
  3013     guarantee(subklass_oop()->is_klass(), "should be klass");
  3016   // Verify siblings
  3017   Klass* super = this->super();
  3018   Klass* sib = next_sibling();
  3019   if (sib != NULL) {
  3020     if (sib == this) {
  3021       fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
  3024     guarantee(sib->is_metadata(), "should be in metaspace");
  3025     guarantee(sib->is_klass(), "should be klass");
  3026     guarantee(sib->super() == super, "siblings should have same superklass");
  3029   // Verify implementor fields
  3030   Klass* im = implementor();
  3031   if (im != NULL) {
  3032     guarantee(is_interface(), "only interfaces should have implementor set");
  3033     guarantee(im->is_klass(), "should be klass");
  3034     guarantee(!im->is_interface() || im == this,
  3035       "implementors cannot be interfaces");
  3038   // Verify local interfaces
  3039   if (local_interfaces()) {
  3040     Array<Klass*>* local_interfaces = this->local_interfaces();
  3041     for (int j = 0; j < local_interfaces->length(); j++) {
  3042       Klass* e = local_interfaces->at(j);
  3043       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
  3047   // Verify transitive interfaces
  3048   if (transitive_interfaces() != NULL) {
  3049     Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
  3050     for (int j = 0; j < transitive_interfaces->length(); j++) {
  3051       Klass* e = transitive_interfaces->at(j);
  3052       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
  3056   // Verify methods
  3057   if (methods() != NULL) {
  3058     Array<Method*>* methods = this->methods();
  3059     for (int j = 0; j < methods->length(); j++) {
  3060       guarantee(methods->at(j)->is_metadata(), "should be in metaspace");
  3061       guarantee(methods->at(j)->is_method(), "non-method in methods array");
  3063     for (int j = 0; j < methods->length() - 1; j++) {
  3064       Method* m1 = methods->at(j);
  3065       Method* m2 = methods->at(j + 1);
  3066       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
  3070   // Verify method ordering
  3071   if (method_ordering() != NULL) {
  3072     Array<int>* method_ordering = this->method_ordering();
  3073     int length = method_ordering->length();
  3074     if (JvmtiExport::can_maintain_original_method_order() ||
  3075         (UseSharedSpaces && length != 0)) {
  3076       guarantee(length == methods()->length(), "invalid method ordering length");
  3077       jlong sum = 0;
  3078       for (int j = 0; j < length; j++) {
  3079         int original_index = method_ordering->at(j);
  3080         guarantee(original_index >= 0, "invalid method ordering index");
  3081         guarantee(original_index < length, "invalid method ordering index");
  3082         sum += original_index;
  3084       // Verify sum of indices 0,1,...,length-1
  3085       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
  3086     } else {
  3087       guarantee(length == 0, "invalid method ordering length");
  3091   // Verify JNI static field identifiers
  3092   if (jni_ids() != NULL) {
  3093     jni_ids()->verify(this);
  3096   // Verify other fields
  3097   if (array_klasses() != NULL) {
  3098     guarantee(array_klasses()->is_metadata(), "should be in metaspace");
  3099     guarantee(array_klasses()->is_klass(), "should be klass");
  3101   if (constants() != NULL) {
  3102     guarantee(constants()->is_metadata(), "should be in metaspace");
  3103     guarantee(constants()->is_constantPool(), "should be constant pool");
  3105   if (protection_domain() != NULL) {
  3106     guarantee(protection_domain()->is_oop(), "should be oop");
  3108   if (host_klass() != NULL) {
  3109     guarantee(host_klass()->is_metadata(), "should be in metaspace");
  3110     guarantee(host_klass()->is_klass(), "should be klass");
  3112   if (signers() != NULL) {
  3113     guarantee(signers()->is_objArray(), "should be obj array");
  3117 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
  3118   Klass::oop_verify_on(obj, st);
  3119   VerifyFieldClosure blk;
  3120   obj->oop_iterate_no_header(&blk);
  3124 // JNIid class for jfieldIDs only
  3125 // Note to reviewers:
  3126 // These JNI functions are just moved over to column 1 and not changed
  3127 // in the compressed oops workspace.
  3128 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
  3129   _holder = holder;
  3130   _offset = offset;
  3131   _next = next;
  3132   debug_only(_is_static_field_id = false;)
  3136 JNIid* JNIid::find(int offset) {
  3137   JNIid* current = this;
  3138   while (current != NULL) {
  3139     if (current->offset() == offset) return current;
  3140     current = current->next();
  3142   return NULL;
  3145 void JNIid::deallocate(JNIid* current) {
  3146   while (current != NULL) {
  3147     JNIid* next = current->next();
  3148     delete current;
  3149     current = next;
  3154 void JNIid::verify(Klass* holder) {
  3155   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
  3156   int end_field_offset;
  3157   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
  3159   JNIid* current = this;
  3160   while (current != NULL) {
  3161     guarantee(current->holder() == holder, "Invalid klass in JNIid");
  3162 #ifdef ASSERT
  3163     int o = current->offset();
  3164     if (current->is_static_field_id()) {
  3165       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
  3167 #endif
  3168     current = current->next();
  3173 #ifdef ASSERT
  3174 void InstanceKlass::set_init_state(ClassState state) {
  3175   bool good_state = is_shared() ? (_init_state <= state)
  3176                                                : (_init_state < state);
  3177   assert(good_state || state == allocated, "illegal state transition");
  3178   _init_state = (u1)state;
  3180 #endif
  3183 // RedefineClasses() support for previous versions:
  3185 // Purge previous versions
  3186 static void purge_previous_versions_internal(InstanceKlass* ik, int emcp_method_count) {
  3187   if (ik->previous_versions() != NULL) {
  3188     // This klass has previous versions so see what we can cleanup
  3189     // while it is safe to do so.
  3191     int deleted_count = 0;    // leave debugging breadcrumbs
  3192     int live_count = 0;
  3193     ClassLoaderData* loader_data = ik->class_loader_data() == NULL ?
  3194                        ClassLoaderData::the_null_class_loader_data() :
  3195                        ik->class_loader_data();
  3197     // RC_TRACE macro has an embedded ResourceMark
  3198     RC_TRACE(0x00000200, ("purge: %s: previous version length=%d",
  3199       ik->external_name(), ik->previous_versions()->length()));
  3201     for (int i = ik->previous_versions()->length() - 1; i >= 0; i--) {
  3202       // check the previous versions array
  3203       PreviousVersionNode * pv_node = ik->previous_versions()->at(i);
  3204       ConstantPool* cp_ref = pv_node->prev_constant_pool();
  3205       assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
  3207       ConstantPool* pvcp = cp_ref;
  3208       if (!pvcp->on_stack()) {
  3209         // If the constant pool isn't on stack, none of the methods
  3210         // are executing.  Delete all the methods, the constant pool and
  3211         // and this previous version node.
  3212         GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3213         if (method_refs != NULL) {
  3214           for (int j = method_refs->length() - 1; j >= 0; j--) {
  3215             Method* method = method_refs->at(j);
  3216             assert(method != NULL, "method ref was unexpectedly cleared");
  3217             method_refs->remove_at(j);
  3218             // method will be freed with associated class.
  3221         // Remove the constant pool
  3222         delete pv_node;
  3223         // Since we are traversing the array backwards, we don't have to
  3224         // do anything special with the index.
  3225         ik->previous_versions()->remove_at(i);
  3226         deleted_count++;
  3227         continue;
  3228       } else {
  3229         RC_TRACE(0x00000200, ("purge: previous version @%d is alive", i));
  3230         assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
  3231         guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
  3232         live_count++;
  3235       // At least one method is live in this previous version, clean out
  3236       // the others or mark them as obsolete.
  3237       GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3238       if (method_refs != NULL) {
  3239         RC_TRACE(0x00000200, ("purge: previous methods length=%d",
  3240           method_refs->length()));
  3241         for (int j = method_refs->length() - 1; j >= 0; j--) {
  3242           Method* method = method_refs->at(j);
  3243           assert(method != NULL, "method ref was unexpectedly cleared");
  3245           // Remove the emcp method if it's not executing
  3246           // If it's been made obsolete by a redefinition of a non-emcp
  3247           // method, mark it as obsolete but leave it to clean up later.
  3248           if (!method->on_stack()) {
  3249             method_refs->remove_at(j);
  3250           } else if (emcp_method_count == 0) {
  3251             method->set_is_obsolete();
  3252           } else {
  3253             // RC_TRACE macro has an embedded ResourceMark
  3254             RC_TRACE(0x00000200,
  3255               ("purge: %s(%s): prev method @%d in version @%d is alive",
  3256               method->name()->as_C_string(),
  3257               method->signature()->as_C_string(), j, i));
  3262     assert(ik->previous_versions()->length() == live_count, "sanity check");
  3263     RC_TRACE(0x00000200,
  3264       ("purge: previous version stats: live=%d, deleted=%d", live_count,
  3265       deleted_count));
  3269 // External interface for use during class unloading.
  3270 void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
  3271   // Call with >0 emcp methods since they are not currently being redefined.
  3272   purge_previous_versions_internal(ik, 1);
  3276 // Potentially add an information node that contains pointers to the
  3277 // interesting parts of the previous version of the_class.
  3278 // This is also where we clean out any unused references.
  3279 // Note that while we delete nodes from the _previous_versions
  3280 // array, we never delete the array itself until the klass is
  3281 // unloaded. The has_been_redefined() query depends on that fact.
  3282 //
  3283 void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
  3284        BitMap* emcp_methods, int emcp_method_count) {
  3285   assert(Thread::current()->is_VM_thread(),
  3286          "only VMThread can add previous versions");
  3288   if (_previous_versions == NULL) {
  3289     // This is the first previous version so make some space.
  3290     // Start with 2 elements under the assumption that the class
  3291     // won't be redefined much.
  3292     _previous_versions =  new (ResourceObj::C_HEAP, mtClass)
  3293                             GrowableArray<PreviousVersionNode *>(2, true);
  3296   ConstantPool* cp_ref = ikh->constants();
  3298   // RC_TRACE macro has an embedded ResourceMark
  3299   RC_TRACE(0x00000400, ("adding previous version ref for %s @%d, EMCP_cnt=%d "
  3300                         "on_stack=%d",
  3301     ikh->external_name(), _previous_versions->length(), emcp_method_count,
  3302     cp_ref->on_stack()));
  3304   // If the constant pool for this previous version of the class
  3305   // is not marked as being on the stack, then none of the methods
  3306   // in this previous version of the class are on the stack so
  3307   // we don't need to create a new PreviousVersionNode. However,
  3308   // we still need to examine older previous versions below.
  3309   Array<Method*>* old_methods = ikh->methods();
  3311   if (cp_ref->on_stack()) {
  3312   PreviousVersionNode * pv_node = NULL;
  3313   if (emcp_method_count == 0) {
  3314       // non-shared ConstantPool gets a reference
  3315       pv_node = new PreviousVersionNode(cp_ref, !cp_ref->is_shared(), NULL);
  3316     RC_TRACE(0x00000400,
  3317         ("add: all methods are obsolete; flushing any EMCP refs"));
  3318   } else {
  3319     int local_count = 0;
  3320       GrowableArray<Method*>* method_refs = new (ResourceObj::C_HEAP, mtClass)
  3321         GrowableArray<Method*>(emcp_method_count, true);
  3322     for (int i = 0; i < old_methods->length(); i++) {
  3323       if (emcp_methods->at(i)) {
  3324           // this old method is EMCP. Save it only if it's on the stack
  3325           Method* old_method = old_methods->at(i);
  3326           if (old_method->on_stack()) {
  3327             method_refs->append(old_method);
  3329         if (++local_count >= emcp_method_count) {
  3330           // no more EMCP methods so bail out now
  3331           break;
  3335       // non-shared ConstantPool gets a reference
  3336       pv_node = new PreviousVersionNode(cp_ref, !cp_ref->is_shared(), method_refs);
  3338     // append new previous version.
  3339   _previous_versions->append(pv_node);
  3342   // Since the caller is the VMThread and we are at a safepoint, this
  3343   // is a good time to clear out unused references.
  3345   RC_TRACE(0x00000400, ("add: previous version length=%d",
  3346     _previous_versions->length()));
  3348   // Purge previous versions not executing on the stack
  3349   purge_previous_versions_internal(this, emcp_method_count);
  3351   int obsolete_method_count = old_methods->length() - emcp_method_count;
  3353   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
  3354       _previous_versions->length() > 0) {
  3355     // We have a mix of obsolete and EMCP methods so we have to
  3356     // clear out any matching EMCP method entries the hard way.
  3357     int local_count = 0;
  3358     for (int i = 0; i < old_methods->length(); i++) {
  3359       if (!emcp_methods->at(i)) {
  3360         // only obsolete methods are interesting
  3361         Method* old_method = old_methods->at(i);
  3362         Symbol* m_name = old_method->name();
  3363         Symbol* m_signature = old_method->signature();
  3365         // we might not have added the last entry
  3366         for (int j = _previous_versions->length() - 1; j >= 0; j--) {
  3367           // check the previous versions array for non executing obsolete methods
  3368           PreviousVersionNode * pv_node = _previous_versions->at(j);
  3370           GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3371           if (method_refs == NULL) {
  3372             // We have run into a PreviousVersion generation where
  3373             // all methods were made obsolete during that generation's
  3374             // RedefineClasses() operation. At the time of that
  3375             // operation, all EMCP methods were flushed so we don't
  3376             // have to go back any further.
  3377             //
  3378             // A NULL method_refs is different than an empty method_refs.
  3379             // We cannot infer any optimizations about older generations
  3380             // from an empty method_refs for the current generation.
  3381             break;
  3384           for (int k = method_refs->length() - 1; k >= 0; k--) {
  3385             Method* method = method_refs->at(k);
  3387             if (!method->is_obsolete() &&
  3388                 method->name() == m_name &&
  3389                 method->signature() == m_signature) {
  3390               // The current RedefineClasses() call has made all EMCP
  3391               // versions of this method obsolete so mark it as obsolete
  3392               // and remove the reference.
  3393               RC_TRACE(0x00000400,
  3394                 ("add: %s(%s): flush obsolete method @%d in version @%d",
  3395                 m_name->as_C_string(), m_signature->as_C_string(), k, j));
  3397               method->set_is_obsolete();
  3398               // Leave obsolete methods on the previous version list to
  3399               // clean up later.
  3400               break;
  3404           // The previous loop may not find a matching EMCP method, but
  3405           // that doesn't mean that we can optimize and not go any
  3406           // further back in the PreviousVersion generations. The EMCP
  3407           // method for this generation could have already been deleted,
  3408           // but there still may be an older EMCP method that has not
  3409           // been deleted.
  3412         if (++local_count >= obsolete_method_count) {
  3413           // no more obsolete methods so bail out now
  3414           break;
  3419 } // end add_previous_version()
  3422 // Determine if InstanceKlass has a previous version.
  3423 bool InstanceKlass::has_previous_version() const {
  3424   return (_previous_versions != NULL && _previous_versions->length() > 0);
  3425 } // end has_previous_version()
  3428 Method* InstanceKlass::method_with_idnum(int idnum) {
  3429   Method* m = NULL;
  3430   if (idnum < methods()->length()) {
  3431     m = methods()->at(idnum);
  3433   if (m == NULL || m->method_idnum() != idnum) {
  3434     for (int index = 0; index < methods()->length(); ++index) {
  3435       m = methods()->at(index);
  3436       if (m->method_idnum() == idnum) {
  3437         return m;
  3441   return m;
  3445 // Construct a PreviousVersionNode entry for the array hung off
  3446 // the InstanceKlass.
  3447 PreviousVersionNode::PreviousVersionNode(ConstantPool* prev_constant_pool,
  3448   bool prev_cp_is_weak, GrowableArray<Method*>* prev_EMCP_methods) {
  3450   _prev_constant_pool = prev_constant_pool;
  3451   _prev_cp_is_weak = prev_cp_is_weak;
  3452   _prev_EMCP_methods = prev_EMCP_methods;
  3456 // Destroy a PreviousVersionNode
  3457 PreviousVersionNode::~PreviousVersionNode() {
  3458   if (_prev_constant_pool != NULL) {
  3459     _prev_constant_pool = NULL;
  3462   if (_prev_EMCP_methods != NULL) {
  3463     delete _prev_EMCP_methods;
  3468 // Construct a PreviousVersionInfo entry
  3469 PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
  3470   _prev_constant_pool_handle = constantPoolHandle();  // NULL handle
  3471   _prev_EMCP_method_handles = NULL;
  3473   ConstantPool* cp = pv_node->prev_constant_pool();
  3474   assert(cp != NULL, "constant pool ref was unexpectedly cleared");
  3475   if (cp == NULL) {
  3476     return;  // robustness
  3479   // make the ConstantPool* safe to return
  3480   _prev_constant_pool_handle = constantPoolHandle(cp);
  3482   GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3483   if (method_refs == NULL) {
  3484     // the InstanceKlass did not have any EMCP methods
  3485     return;
  3488   _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
  3490   int n_methods = method_refs->length();
  3491   for (int i = 0; i < n_methods; i++) {
  3492     Method* method = method_refs->at(i);
  3493     assert (method != NULL, "method has been cleared");
  3494     if (method == NULL) {
  3495       continue;  // robustness
  3497     // make the Method* safe to return
  3498     _prev_EMCP_method_handles->append(methodHandle(method));
  3503 // Destroy a PreviousVersionInfo
  3504 PreviousVersionInfo::~PreviousVersionInfo() {
  3505   // Since _prev_EMCP_method_handles is not C-heap allocated, we
  3506   // don't have to delete it.
  3510 // Construct a helper for walking the previous versions array
  3511 PreviousVersionWalker::PreviousVersionWalker(InstanceKlass *ik) {
  3512   _previous_versions = ik->previous_versions();
  3513   _current_index = 0;
  3514   // _hm needs no initialization
  3515   _current_p = NULL;
  3519 // Destroy a PreviousVersionWalker
  3520 PreviousVersionWalker::~PreviousVersionWalker() {
  3521   // Delete the current info just in case the caller didn't walk to
  3522   // the end of the previous versions list. No harm if _current_p is
  3523   // already NULL.
  3524   delete _current_p;
  3526   // When _hm is destroyed, all the Handles returned in
  3527   // PreviousVersionInfo objects will be destroyed.
  3528   // Also, after this destructor is finished it will be
  3529   // safe to delete the GrowableArray allocated in the
  3530   // PreviousVersionInfo objects.
  3534 // Return the interesting information for the next previous version
  3535 // of the klass. Returns NULL if there are no more previous versions.
  3536 PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
  3537   if (_previous_versions == NULL) {
  3538     // no previous versions so nothing to return
  3539     return NULL;
  3542   delete _current_p;  // cleanup the previous info for the caller
  3543   _current_p = NULL;  // reset to NULL so we don't delete same object twice
  3545   int length = _previous_versions->length();
  3547   while (_current_index < length) {
  3548     PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
  3549     PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP, mtClass)
  3550                                           PreviousVersionInfo(pv_node);
  3552     constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
  3553     assert (!cp_h.is_null(), "null cp found in previous version");
  3555     // The caller will need to delete pv_info when they are done with it.
  3556     _current_p = pv_info;
  3557     return pv_info;
  3560   // all of the underlying nodes' info has been deleted
  3561   return NULL;
  3562 } // end next_previous_version()

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