src/share/vm/oops/instanceKlass.cpp

Tue, 02 Sep 2014 21:27:08 -0400

author
dholmes
date
Tue, 02 Sep 2014 21:27:08 -0400
changeset 7191
7dca5ed0e13d
parent 7097
14b8221771dc
child 7290
90257dfad6e3
permissions
-rw-r--r--

8046210: Missing memory barrier when reading init_lock
Reviewed-by: fparain, dcubed, mdoerr
Contributed-by: Bill Pittore <bill.pittore@oracle.com>

     1 /*
     2  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    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/heapInspection.hpp"
    38 #include "memory/iterator.inline.hpp"
    39 #include "memory/metadataFactory.hpp"
    40 #include "memory/oopFactory.hpp"
    41 #include "oops/fieldStreams.hpp"
    42 #include "oops/instanceClassLoaderKlass.hpp"
    43 #include "oops/instanceKlass.hpp"
    44 #include "oops/instanceMirrorKlass.hpp"
    45 #include "oops/instanceOop.hpp"
    46 #include "oops/klass.inline.hpp"
    47 #include "oops/method.hpp"
    48 #include "oops/oop.inline.hpp"
    49 #include "oops/symbol.hpp"
    50 #include "prims/jvmtiExport.hpp"
    51 #include "prims/jvmtiRedefineClassesTrace.hpp"
    52 #include "prims/jvmtiRedefineClasses.hpp"
    53 #include "prims/methodComparator.hpp"
    54 #include "runtime/fieldDescriptor.hpp"
    55 #include "runtime/handles.inline.hpp"
    56 #include "runtime/javaCalls.hpp"
    57 #include "runtime/mutexLocker.hpp"
    58 #include "runtime/orderAccess.inline.hpp"
    59 #include "runtime/thread.inline.hpp"
    60 #include "services/classLoadingService.hpp"
    61 #include "services/threadService.hpp"
    62 #include "utilities/dtrace.hpp"
    63 #include "utilities/macros.hpp"
    64 #if INCLUDE_ALL_GCS
    65 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp"
    66 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
    67 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
    68 #include "gc_implementation/g1/g1RemSet.inline.hpp"
    69 #include "gc_implementation/g1/heapRegionManager.inline.hpp"
    70 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
    71 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp"
    72 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
    73 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
    74 #include "oops/oop.pcgc.inline.hpp"
    75 #endif // INCLUDE_ALL_GCS
    76 #ifdef COMPILER1
    77 #include "c1/c1_Compiler.hpp"
    78 #endif
    80 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
    82 #ifdef DTRACE_ENABLED
    84 #ifndef USDT2
    86 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
    87   char*, intptr_t, oop, intptr_t);
    88 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
    89   char*, intptr_t, oop, intptr_t, int);
    90 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
    91   char*, intptr_t, oop, intptr_t, int);
    92 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
    93   char*, intptr_t, oop, intptr_t, int);
    94 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
    95   char*, intptr_t, oop, intptr_t, int);
    96 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
    97   char*, intptr_t, oop, intptr_t, int);
    98 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
    99   char*, intptr_t, oop, intptr_t, int);
   100 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
   101   char*, intptr_t, oop, intptr_t, int);
   103 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
   104   {                                                              \
   105     char* data = NULL;                                           \
   106     int len = 0;                                                 \
   107     Symbol* name = (clss)->name();                               \
   108     if (name != NULL) {                                          \
   109       data = (char*)name->bytes();                               \
   110       len = name->utf8_length();                                 \
   111     }                                                            \
   112     HS_DTRACE_PROBE4(hotspot, class__initialization__##type,     \
   113       data, len, SOLARIS_ONLY((void *))(clss)->class_loader(), thread_type);           \
   114   }
   116 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
   117   {                                                              \
   118     char* data = NULL;                                           \
   119     int len = 0;                                                 \
   120     Symbol* name = (clss)->name();                               \
   121     if (name != NULL) {                                          \
   122       data = (char*)name->bytes();                               \
   123       len = name->utf8_length();                                 \
   124     }                                                            \
   125     HS_DTRACE_PROBE5(hotspot, class__initialization__##type,     \
   126       data, len, SOLARIS_ONLY((void *))(clss)->class_loader(), thread_type, wait);     \
   127   }
   128 #else /* USDT2 */
   130 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
   131 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
   132 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
   133 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
   134 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
   135 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
   136 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
   137 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
   138 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
   139   {                                                              \
   140     char* data = NULL;                                           \
   141     int len = 0;                                                 \
   142     Symbol* name = (clss)->name();                               \
   143     if (name != NULL) {                                          \
   144       data = (char*)name->bytes();                               \
   145       len = name->utf8_length();                                 \
   146     }                                                            \
   147     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
   148       data, len, (clss)->class_loader(), thread_type);           \
   149   }
   151 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
   152   {                                                              \
   153     char* data = NULL;                                           \
   154     int len = 0;                                                 \
   155     Symbol* name = (clss)->name();                               \
   156     if (name != NULL) {                                          \
   157       data = (char*)name->bytes();                               \
   158       len = name->utf8_length();                                 \
   159     }                                                            \
   160     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
   161       data, len, (clss)->class_loader(), thread_type, wait);     \
   162   }
   163 #endif /* USDT2 */
   165 #else //  ndef DTRACE_ENABLED
   167 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
   168 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
   170 #endif //  ndef DTRACE_ENABLED
   172 volatile int InstanceKlass::_total_instanceKlass_count = 0;
   174 InstanceKlass* InstanceKlass::allocate_instance_klass(
   175                                               ClassLoaderData* loader_data,
   176                                               int vtable_len,
   177                                               int itable_len,
   178                                               int static_field_size,
   179                                               int nonstatic_oop_map_size,
   180                                               ReferenceType rt,
   181                                               AccessFlags access_flags,
   182                                               Symbol* name,
   183                                               Klass* super_klass,
   184                                               bool is_anonymous,
   185                                               TRAPS) {
   187   int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
   188                                  access_flags.is_interface(), is_anonymous);
   190   // Allocation
   191   InstanceKlass* ik;
   192   if (rt == REF_NONE) {
   193     if (name == vmSymbols::java_lang_Class()) {
   194       ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
   195         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   196         access_flags, is_anonymous);
   197     } else if (name == vmSymbols::java_lang_ClassLoader() ||
   198           (SystemDictionary::ClassLoader_klass_loaded() &&
   199           super_klass != NULL &&
   200           super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
   201       ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
   202         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   203         access_flags, is_anonymous);
   204     } else {
   205       // normal class
   206       ik = new (loader_data, size, THREAD) InstanceKlass(
   207         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   208         access_flags, is_anonymous);
   209     }
   210   } else {
   211     // reference klass
   212     ik = new (loader_data, size, THREAD) InstanceRefKlass(
   213         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   214         access_flags, is_anonymous);
   215   }
   217   // Check for pending exception before adding to the loader data and incrementing
   218   // class count.  Can get OOM here.
   219   if (HAS_PENDING_EXCEPTION) {
   220     return NULL;
   221   }
   223   // Add all classes to our internal class loader list here,
   224   // including classes in the bootstrap (NULL) class loader.
   225   loader_data->add_class(ik);
   227   Atomic::inc(&_total_instanceKlass_count);
   228   return ik;
   229 }
   232 // copy method ordering from resource area to Metaspace
   233 void InstanceKlass::copy_method_ordering(intArray* m, TRAPS) {
   234   if (m != NULL) {
   235     // allocate a new array and copy contents (memcpy?)
   236     _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
   237     for (int i = 0; i < m->length(); i++) {
   238       _method_ordering->at_put(i, m->at(i));
   239     }
   240   } else {
   241     _method_ordering = Universe::the_empty_int_array();
   242   }
   243 }
   245 // create a new array of vtable_indices for default methods
   246 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
   247   Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
   248   assert(default_vtable_indices() == NULL, "only create once");
   249   set_default_vtable_indices(vtable_indices);
   250   return vtable_indices;
   251 }
   253 InstanceKlass::InstanceKlass(int vtable_len,
   254                              int itable_len,
   255                              int static_field_size,
   256                              int nonstatic_oop_map_size,
   257                              ReferenceType rt,
   258                              AccessFlags access_flags,
   259                              bool is_anonymous) {
   260   No_Safepoint_Verifier no_safepoint; // until k becomes parsable
   262   int iksize = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
   263                                    access_flags.is_interface(), is_anonymous);
   265   set_vtable_length(vtable_len);
   266   set_itable_length(itable_len);
   267   set_static_field_size(static_field_size);
   268   set_nonstatic_oop_map_size(nonstatic_oop_map_size);
   269   set_access_flags(access_flags);
   270   _misc_flags = 0;  // initialize to zero
   271   set_is_anonymous(is_anonymous);
   272   assert(size() == iksize, "wrong size for object");
   274   set_array_klasses(NULL);
   275   set_methods(NULL);
   276   set_method_ordering(NULL);
   277   set_default_methods(NULL);
   278   set_default_vtable_indices(NULL);
   279   set_local_interfaces(NULL);
   280   set_transitive_interfaces(NULL);
   281   init_implementor();
   282   set_fields(NULL, 0);
   283   set_constants(NULL);
   284   set_class_loader_data(NULL);
   285   set_source_file_name_index(0);
   286   set_source_debug_extension(NULL, 0);
   287   set_array_name(NULL);
   288   set_inner_classes(NULL);
   289   set_static_oop_field_count(0);
   290   set_nonstatic_field_size(0);
   291   set_is_marked_dependent(false);
   292   set_has_unloaded_dependent(false);
   293   set_init_state(InstanceKlass::allocated);
   294   set_init_thread(NULL);
   295   set_reference_type(rt);
   296   set_oop_map_cache(NULL);
   297   set_jni_ids(NULL);
   298   set_osr_nmethods_head(NULL);
   299   set_breakpoints(NULL);
   300   init_previous_versions();
   301   set_generic_signature_index(0);
   302   release_set_methods_jmethod_ids(NULL);
   303   set_annotations(NULL);
   304   set_jvmti_cached_class_field_map(NULL);
   305   set_initial_method_idnum(0);
   306   _dependencies = NULL;
   307   set_jvmti_cached_class_field_map(NULL);
   308   set_cached_class_file(NULL);
   309   set_initial_method_idnum(0);
   310   set_minor_version(0);
   311   set_major_version(0);
   312   NOT_PRODUCT(_verify_count = 0;)
   314   // initialize the non-header words to zero
   315   intptr_t* p = (intptr_t*)this;
   316   for (int index = InstanceKlass::header_size(); index < iksize; index++) {
   317     p[index] = NULL_WORD;
   318   }
   320   // Set temporary value until parseClassFile updates it with the real instance
   321   // size.
   322   set_layout_helper(Klass::instance_layout_helper(0, true));
   323 }
   326 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
   327                                        Array<Method*>* methods) {
   328   if (methods != NULL && methods != Universe::the_empty_method_array() &&
   329       !methods->is_shared()) {
   330     for (int i = 0; i < methods->length(); i++) {
   331       Method* method = methods->at(i);
   332       if (method == NULL) continue;  // maybe null if error processing
   333       // Only want to delete methods that are not executing for RedefineClasses.
   334       // The previous version will point to them so they're not totally dangling
   335       assert (!method->on_stack(), "shouldn't be called with methods on stack");
   336       MetadataFactory::free_metadata(loader_data, method);
   337     }
   338     MetadataFactory::free_array<Method*>(loader_data, methods);
   339   }
   340 }
   342 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
   343                                           Klass* super_klass,
   344                                           Array<Klass*>* local_interfaces,
   345                                           Array<Klass*>* transitive_interfaces) {
   346   // Only deallocate transitive interfaces if not empty, same as super class
   347   // or same as local interfaces.  See code in parseClassFile.
   348   Array<Klass*>* ti = transitive_interfaces;
   349   if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
   350     // check that the interfaces don't come from super class
   351     Array<Klass*>* sti = (super_klass == NULL) ? NULL :
   352                     InstanceKlass::cast(super_klass)->transitive_interfaces();
   353     if (ti != sti && ti != NULL && !ti->is_shared()) {
   354       MetadataFactory::free_array<Klass*>(loader_data, ti);
   355     }
   356   }
   358   // local interfaces can be empty
   359   if (local_interfaces != Universe::the_empty_klass_array() &&
   360       local_interfaces != NULL && !local_interfaces->is_shared()) {
   361     MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
   362   }
   363 }
   365 // This function deallocates the metadata and C heap pointers that the
   366 // InstanceKlass points to.
   367 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
   369   // Orphan the mirror first, CMS thinks it's still live.
   370   if (java_mirror() != NULL) {
   371     java_lang_Class::set_klass(java_mirror(), NULL);
   372   }
   374   // Need to take this class off the class loader data list.
   375   loader_data->remove_class(this);
   377   // The array_klass for this class is created later, after error handling.
   378   // For class redefinition, we keep the original class so this scratch class
   379   // doesn't have an array class.  Either way, assert that there is nothing
   380   // to deallocate.
   381   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
   383   // Release C heap allocated data that this might point to, which includes
   384   // reference counting symbol names.
   385   release_C_heap_structures();
   387   deallocate_methods(loader_data, methods());
   388   set_methods(NULL);
   390   if (method_ordering() != NULL &&
   391       method_ordering() != Universe::the_empty_int_array() &&
   392       !method_ordering()->is_shared()) {
   393     MetadataFactory::free_array<int>(loader_data, method_ordering());
   394   }
   395   set_method_ordering(NULL);
   397   // default methods can be empty
   398   if (default_methods() != NULL &&
   399       default_methods() != Universe::the_empty_method_array() &&
   400       !default_methods()->is_shared()) {
   401     MetadataFactory::free_array<Method*>(loader_data, default_methods());
   402   }
   403   // Do NOT deallocate the default methods, they are owned by superinterfaces.
   404   set_default_methods(NULL);
   406   // default methods vtable indices can be empty
   407   if (default_vtable_indices() != NULL &&
   408       !default_vtable_indices()->is_shared()) {
   409     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
   410   }
   411   set_default_vtable_indices(NULL);
   414   // This array is in Klass, but remove it with the InstanceKlass since
   415   // this place would be the only caller and it can share memory with transitive
   416   // interfaces.
   417   if (secondary_supers() != NULL &&
   418       secondary_supers() != Universe::the_empty_klass_array() &&
   419       secondary_supers() != transitive_interfaces() &&
   420       !secondary_supers()->is_shared()) {
   421     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
   422   }
   423   set_secondary_supers(NULL);
   425   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
   426   set_transitive_interfaces(NULL);
   427   set_local_interfaces(NULL);
   429   if (fields() != NULL && !fields()->is_shared()) {
   430     MetadataFactory::free_array<jushort>(loader_data, fields());
   431   }
   432   set_fields(NULL, 0);
   434   // If a method from a redefined class is using this constant pool, don't
   435   // delete it, yet.  The new class's previous version will point to this.
   436   if (constants() != NULL) {
   437     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
   438     if (!constants()->is_shared()) {
   439       MetadataFactory::free_metadata(loader_data, constants());
   440     }
   441     set_constants(NULL);
   442   }
   444   if (inner_classes() != NULL &&
   445       inner_classes() != Universe::the_empty_short_array() &&
   446       !inner_classes()->is_shared()) {
   447     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
   448   }
   449   set_inner_classes(NULL);
   451   // We should deallocate the Annotations instance if it's not in shared spaces.
   452   if (annotations() != NULL && !annotations()->is_shared()) {
   453     MetadataFactory::free_metadata(loader_data, annotations());
   454   }
   455   set_annotations(NULL);
   456 }
   458 bool InstanceKlass::should_be_initialized() const {
   459   return !is_initialized();
   460 }
   462 klassVtable* InstanceKlass::vtable() const {
   463   return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
   464 }
   466 klassItable* InstanceKlass::itable() const {
   467   return new klassItable(instanceKlassHandle(this));
   468 }
   470 void InstanceKlass::eager_initialize(Thread *thread) {
   471   if (!EagerInitialization) return;
   473   if (this->is_not_initialized()) {
   474     // abort if the the class has a class initializer
   475     if (this->class_initializer() != NULL) return;
   477     // abort if it is java.lang.Object (initialization is handled in genesis)
   478     Klass* super = this->super();
   479     if (super == NULL) return;
   481     // abort if the super class should be initialized
   482     if (!InstanceKlass::cast(super)->is_initialized()) return;
   484     // call body to expose the this pointer
   485     instanceKlassHandle this_oop(thread, this);
   486     eager_initialize_impl(this_oop);
   487   }
   488 }
   490 // JVMTI spec thinks there are signers and protection domain in the
   491 // instanceKlass.  These accessors pretend these fields are there.
   492 // The hprof specification also thinks these fields are in InstanceKlass.
   493 oop InstanceKlass::protection_domain() const {
   494   // return the protection_domain from the mirror
   495   return java_lang_Class::protection_domain(java_mirror());
   496 }
   498 // To remove these from requires an incompatible change and CCC request.
   499 objArrayOop InstanceKlass::signers() const {
   500   // return the signers from the mirror
   501   return java_lang_Class::signers(java_mirror());
   502 }
   504 oop InstanceKlass::init_lock() const {
   505   // return the init lock from the mirror
   506   oop lock = java_lang_Class::init_lock(java_mirror());
   507   // Prevent reordering with any access of initialization state
   508   OrderAccess::loadload();
   509   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
   510          "only fully initialized state can have a null lock");
   511   return lock;
   512 }
   514 // Set the initialization lock to null so the object can be GC'ed.  Any racing
   515 // threads to get this lock will see a null lock and will not lock.
   516 // That's okay because they all check for initialized state after getting
   517 // the lock and return.
   518 void InstanceKlass::fence_and_clear_init_lock() {
   519   // make sure previous stores are all done, notably the init_state.
   520   OrderAccess::storestore();
   521   java_lang_Class::set_init_lock(java_mirror(), NULL);
   522   assert(!is_not_initialized(), "class must be initialized now");
   523 }
   525 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
   526   EXCEPTION_MARK;
   527   oop init_lock = this_oop->init_lock();
   528   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   530   // abort if someone beat us to the initialization
   531   if (!this_oop->is_not_initialized()) return;  // note: not equivalent to is_initialized()
   533   ClassState old_state = this_oop->init_state();
   534   link_class_impl(this_oop, true, THREAD);
   535   if (HAS_PENDING_EXCEPTION) {
   536     CLEAR_PENDING_EXCEPTION;
   537     // Abort if linking the class throws an exception.
   539     // Use a test to avoid redundantly resetting the state if there's
   540     // no change.  Set_init_state() asserts that state changes make
   541     // progress, whereas here we might just be spinning in place.
   542     if( old_state != this_oop->_init_state )
   543       this_oop->set_init_state (old_state);
   544   } else {
   545     // linking successfull, mark class as initialized
   546     this_oop->set_init_state (fully_initialized);
   547     this_oop->fence_and_clear_init_lock();
   548     // trace
   549     if (TraceClassInitialization) {
   550       ResourceMark rm(THREAD);
   551       tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
   552     }
   553   }
   554 }
   557 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
   558 // process. The step comments refers to the procedure described in that section.
   559 // Note: implementation moved to static method to expose the this pointer.
   560 void InstanceKlass::initialize(TRAPS) {
   561   if (this->should_be_initialized()) {
   562     HandleMark hm(THREAD);
   563     instanceKlassHandle this_oop(THREAD, this);
   564     initialize_impl(this_oop, CHECK);
   565     // Note: at this point the class may be initialized
   566     //       OR it may be in the state of being initialized
   567     //       in case of recursive initialization!
   568   } else {
   569     assert(is_initialized(), "sanity check");
   570   }
   571 }
   574 bool InstanceKlass::verify_code(
   575     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
   576   // 1) Verify the bytecodes
   577   Verifier::Mode mode =
   578     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
   579   return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
   580 }
   583 // Used exclusively by the shared spaces dump mechanism to prevent
   584 // classes mapped into the shared regions in new VMs from appearing linked.
   586 void InstanceKlass::unlink_class() {
   587   assert(is_linked(), "must be linked");
   588   _init_state = loaded;
   589 }
   591 void InstanceKlass::link_class(TRAPS) {
   592   assert(is_loaded(), "must be loaded");
   593   if (!is_linked()) {
   594     HandleMark hm(THREAD);
   595     instanceKlassHandle this_oop(THREAD, this);
   596     link_class_impl(this_oop, true, CHECK);
   597   }
   598 }
   600 // Called to verify that a class can link during initialization, without
   601 // throwing a VerifyError.
   602 bool InstanceKlass::link_class_or_fail(TRAPS) {
   603   assert(is_loaded(), "must be loaded");
   604   if (!is_linked()) {
   605     HandleMark hm(THREAD);
   606     instanceKlassHandle this_oop(THREAD, this);
   607     link_class_impl(this_oop, false, CHECK_false);
   608   }
   609   return is_linked();
   610 }
   612 bool InstanceKlass::link_class_impl(
   613     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
   614   // check for error state
   615   if (this_oop->is_in_error_state()) {
   616     ResourceMark rm(THREAD);
   617     THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
   618                this_oop->external_name(), false);
   619   }
   620   // return if already verified
   621   if (this_oop->is_linked()) {
   622     return true;
   623   }
   625   // Timing
   626   // timer handles recursion
   627   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
   628   JavaThread* jt = (JavaThread*)THREAD;
   630   // link super class before linking this class
   631   instanceKlassHandle super(THREAD, this_oop->super());
   632   if (super.not_null()) {
   633     if (super->is_interface()) {  // check if super class is an interface
   634       ResourceMark rm(THREAD);
   635       Exceptions::fthrow(
   636         THREAD_AND_LOCATION,
   637         vmSymbols::java_lang_IncompatibleClassChangeError(),
   638         "class %s has interface %s as super class",
   639         this_oop->external_name(),
   640         super->external_name()
   641       );
   642       return false;
   643     }
   645     link_class_impl(super, throw_verifyerror, CHECK_false);
   646   }
   648   // link all interfaces implemented by this class before linking this class
   649   Array<Klass*>* interfaces = this_oop->local_interfaces();
   650   int num_interfaces = interfaces->length();
   651   for (int index = 0; index < num_interfaces; index++) {
   652     HandleMark hm(THREAD);
   653     instanceKlassHandle ih(THREAD, interfaces->at(index));
   654     link_class_impl(ih, throw_verifyerror, CHECK_false);
   655   }
   657   // in case the class is linked in the process of linking its superclasses
   658   if (this_oop->is_linked()) {
   659     return true;
   660   }
   662   // trace only the link time for this klass that includes
   663   // the verification time
   664   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
   665                              ClassLoader::perf_class_link_selftime(),
   666                              ClassLoader::perf_classes_linked(),
   667                              jt->get_thread_stat()->perf_recursion_counts_addr(),
   668                              jt->get_thread_stat()->perf_timers_addr(),
   669                              PerfClassTraceTime::CLASS_LINK);
   671   // verification & rewriting
   672   {
   673     oop init_lock = this_oop->init_lock();
   674     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   675     // rewritten will have been set if loader constraint error found
   676     // on an earlier link attempt
   677     // don't verify or rewrite if already rewritten
   679     if (!this_oop->is_linked()) {
   680       if (!this_oop->is_rewritten()) {
   681         {
   682           // Timer includes any side effects of class verification (resolution,
   683           // etc), but not recursive entry into verify_code().
   684           PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
   685                                    ClassLoader::perf_class_verify_selftime(),
   686                                    ClassLoader::perf_classes_verified(),
   687                                    jt->get_thread_stat()->perf_recursion_counts_addr(),
   688                                    jt->get_thread_stat()->perf_timers_addr(),
   689                                    PerfClassTraceTime::CLASS_VERIFY);
   690           bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
   691           if (!verify_ok) {
   692             return false;
   693           }
   694         }
   696         // Just in case a side-effect of verify linked this class already
   697         // (which can sometimes happen since the verifier loads classes
   698         // using custom class loaders, which are free to initialize things)
   699         if (this_oop->is_linked()) {
   700           return true;
   701         }
   703         // also sets rewritten
   704         this_oop->rewrite_class(CHECK_false);
   705       }
   707       // relocate jsrs and link methods after they are all rewritten
   708       this_oop->link_methods(CHECK_false);
   710       // Initialize the vtable and interface table after
   711       // methods have been rewritten since rewrite may
   712       // fabricate new Method*s.
   713       // also does loader constraint checking
   714       if (!this_oop()->is_shared()) {
   715         ResourceMark rm(THREAD);
   716         this_oop->vtable()->initialize_vtable(true, CHECK_false);
   717         this_oop->itable()->initialize_itable(true, CHECK_false);
   718       }
   719 #ifdef ASSERT
   720       else {
   721         ResourceMark rm(THREAD);
   722         this_oop->vtable()->verify(tty, true);
   723         // In case itable verification is ever added.
   724         // this_oop->itable()->verify(tty, true);
   725       }
   726 #endif
   727       this_oop->set_init_state(linked);
   728       if (JvmtiExport::should_post_class_prepare()) {
   729         Thread *thread = THREAD;
   730         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
   731         JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
   732       }
   733     }
   734   }
   735   return true;
   736 }
   739 // Rewrite the byte codes of all of the methods of a class.
   740 // The rewriter must be called exactly once. Rewriting must happen after
   741 // verification but before the first method of the class is executed.
   742 void InstanceKlass::rewrite_class(TRAPS) {
   743   assert(is_loaded(), "must be loaded");
   744   instanceKlassHandle this_oop(THREAD, this);
   745   if (this_oop->is_rewritten()) {
   746     assert(this_oop()->is_shared(), "rewriting an unshared class?");
   747     return;
   748   }
   749   Rewriter::rewrite(this_oop, CHECK);
   750   this_oop->set_rewritten();
   751 }
   753 // Now relocate and link method entry points after class is rewritten.
   754 // This is outside is_rewritten flag. In case of an exception, it can be
   755 // executed more than once.
   756 void InstanceKlass::link_methods(TRAPS) {
   757   int len = methods()->length();
   758   for (int i = len-1; i >= 0; i--) {
   759     methodHandle m(THREAD, methods()->at(i));
   761     // Set up method entry points for compiler and interpreter    .
   762     m->link_method(m, CHECK);
   764     // This is for JVMTI and unrelated to relocator but the last thing we do
   765 #ifdef ASSERT
   766     if (StressMethodComparator) {
   767       ResourceMark rm(THREAD);
   768       static int nmc = 0;
   769       for (int j = i; j >= 0 && j >= i-4; j--) {
   770         if ((++nmc % 1000) == 0)  tty->print_cr("Have run MethodComparator %d times...", nmc);
   771         bool z = MethodComparator::methods_EMCP(m(),
   772                    methods()->at(j));
   773         if (j == i && !z) {
   774           tty->print("MethodComparator FAIL: "); m->print(); m->print_codes();
   775           assert(z, "method must compare equal to itself");
   776         }
   777       }
   778     }
   779 #endif //ASSERT
   780   }
   781 }
   784 void InstanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
   785   // Make sure klass is linked (verified) before initialization
   786   // A class could already be verified, since it has been reflected upon.
   787   this_oop->link_class(CHECK);
   789   DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_oop()), -1);
   791   bool wait = false;
   793   // refer to the JVM book page 47 for description of steps
   794   // Step 1
   795   {
   796     oop init_lock = this_oop->init_lock();
   797     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   799     Thread *self = THREAD; // it's passed the current thread
   801     // Step 2
   802     // If we were to use wait() instead of waitInterruptibly() then
   803     // we might end up throwing IE from link/symbol resolution sites
   804     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
   805     while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
   806         wait = true;
   807       ol.waitUninterruptibly(CHECK);
   808     }
   810     // Step 3
   811     if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
   812       DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_oop()), -1,wait);
   813       return;
   814     }
   816     // Step 4
   817     if (this_oop->is_initialized()) {
   818       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_oop()), -1,wait);
   819       return;
   820     }
   822     // Step 5
   823     if (this_oop->is_in_error_state()) {
   824       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_oop()), -1,wait);
   825       ResourceMark rm(THREAD);
   826       const char* desc = "Could not initialize class ";
   827       const char* className = this_oop->external_name();
   828       size_t msglen = strlen(desc) + strlen(className) + 1;
   829       char* message = NEW_RESOURCE_ARRAY(char, msglen);
   830       if (NULL == message) {
   831         // Out of memory: can't create detailed error message
   832         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
   833       } else {
   834         jio_snprintf(message, msglen, "%s%s", desc, className);
   835         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
   836       }
   837     }
   839     // Step 6
   840     this_oop->set_init_state(being_initialized);
   841     this_oop->set_init_thread(self);
   842   }
   844   // Step 7
   845   Klass* super_klass = this_oop->super();
   846   if (super_klass != NULL && !this_oop->is_interface() && super_klass->should_be_initialized()) {
   847     super_klass->initialize(THREAD);
   849     if (HAS_PENDING_EXCEPTION) {
   850       Handle e(THREAD, PENDING_EXCEPTION);
   851       CLEAR_PENDING_EXCEPTION;
   852       {
   853         EXCEPTION_MARK;
   854         this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
   855         CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, superclass initialization error is thrown below
   856       }
   857       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_oop()), -1,wait);
   858       THROW_OOP(e());
   859     }
   860   }
   862   if (this_oop->has_default_methods()) {
   863     // Step 7.5: initialize any interfaces which have default methods
   864     for (int i = 0; i < this_oop->local_interfaces()->length(); ++i) {
   865       Klass* iface = this_oop->local_interfaces()->at(i);
   866       InstanceKlass* ik = InstanceKlass::cast(iface);
   867       if (ik->has_default_methods() && ik->should_be_initialized()) {
   868         ik->initialize(THREAD);
   870         if (HAS_PENDING_EXCEPTION) {
   871           Handle e(THREAD, PENDING_EXCEPTION);
   872           CLEAR_PENDING_EXCEPTION;
   873           {
   874             EXCEPTION_MARK;
   875             // Locks object, set state, and notify all waiting threads
   876             this_oop->set_initialization_state_and_notify(
   877                 initialization_error, THREAD);
   879             // ignore any exception thrown, superclass initialization error is
   880             // thrown below
   881             CLEAR_PENDING_EXCEPTION;
   882           }
   883           DTRACE_CLASSINIT_PROBE_WAIT(
   884               super__failed, InstanceKlass::cast(this_oop()), -1, wait);
   885           THROW_OOP(e());
   886         }
   887       }
   888     }
   889   }
   891   // Step 8
   892   {
   893     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
   894     JavaThread* jt = (JavaThread*)THREAD;
   895     DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_oop()), -1,wait);
   896     // Timer includes any side effects of class initialization (resolution,
   897     // etc), but not recursive entry into call_class_initializer().
   898     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
   899                              ClassLoader::perf_class_init_selftime(),
   900                              ClassLoader::perf_classes_inited(),
   901                              jt->get_thread_stat()->perf_recursion_counts_addr(),
   902                              jt->get_thread_stat()->perf_timers_addr(),
   903                              PerfClassTraceTime::CLASS_CLINIT);
   904     this_oop->call_class_initializer(THREAD);
   905   }
   907   // Step 9
   908   if (!HAS_PENDING_EXCEPTION) {
   909     this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
   910     { ResourceMark rm(THREAD);
   911       debug_only(this_oop->vtable()->verify(tty, true);)
   912     }
   913   }
   914   else {
   915     // Step 10 and 11
   916     Handle e(THREAD, PENDING_EXCEPTION);
   917     CLEAR_PENDING_EXCEPTION;
   918     {
   919       EXCEPTION_MARK;
   920       this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
   921       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
   922     }
   923     DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_oop()), -1,wait);
   924     if (e->is_a(SystemDictionary::Error_klass())) {
   925       THROW_OOP(e());
   926     } else {
   927       JavaCallArguments args(e);
   928       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
   929                 vmSymbols::throwable_void_signature(),
   930                 &args);
   931     }
   932   }
   933   DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_oop()), -1,wait);
   934 }
   937 // Note: implementation moved to static method to expose the this pointer.
   938 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
   939   instanceKlassHandle kh(THREAD, this);
   940   set_initialization_state_and_notify_impl(kh, state, CHECK);
   941 }
   943 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
   944   oop init_lock = this_oop->init_lock();
   945   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   946   this_oop->set_init_state(state);
   947   this_oop->fence_and_clear_init_lock();
   948   ol.notify_all(CHECK);
   949 }
   951 // The embedded _implementor field can only record one implementor.
   952 // When there are more than one implementors, the _implementor field
   953 // is set to the interface Klass* itself. Following are the possible
   954 // values for the _implementor field:
   955 //   NULL                  - no implementor
   956 //   implementor Klass*    - one implementor
   957 //   self                  - more than one implementor
   958 //
   959 // The _implementor field only exists for interfaces.
   960 void InstanceKlass::add_implementor(Klass* k) {
   961   assert(Compile_lock->owned_by_self(), "");
   962   assert(is_interface(), "not interface");
   963   // Filter out my subinterfaces.
   964   // (Note: Interfaces are never on the subklass list.)
   965   if (InstanceKlass::cast(k)->is_interface()) return;
   967   // Filter out subclasses whose supers already implement me.
   968   // (Note: CHA must walk subclasses of direct implementors
   969   // in order to locate indirect implementors.)
   970   Klass* sk = InstanceKlass::cast(k)->super();
   971   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
   972     // We only need to check one immediate superclass, since the
   973     // implements_interface query looks at transitive_interfaces.
   974     // Any supers of the super have the same (or fewer) transitive_interfaces.
   975     return;
   977   Klass* ik = implementor();
   978   if (ik == NULL) {
   979     set_implementor(k);
   980   } else if (ik != this) {
   981     // There is already an implementor. Use itself as an indicator of
   982     // more than one implementors.
   983     set_implementor(this);
   984   }
   986   // The implementor also implements the transitive_interfaces
   987   for (int index = 0; index < local_interfaces()->length(); index++) {
   988     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
   989   }
   990 }
   992 void InstanceKlass::init_implementor() {
   993   if (is_interface()) {
   994     set_implementor(NULL);
   995   }
   996 }
   999 void InstanceKlass::process_interfaces(Thread *thread) {
  1000   // link this class into the implementors list of every interface it implements
  1001   Klass* this_as_klass_oop = this;
  1002   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
  1003     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
  1004     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
  1005     assert(interf->is_interface(), "expected interface");
  1006     interf->add_implementor(this_as_klass_oop);
  1010 bool InstanceKlass::can_be_primary_super_slow() const {
  1011   if (is_interface())
  1012     return false;
  1013   else
  1014     return Klass::can_be_primary_super_slow();
  1017 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
  1018   // The secondaries are the implemented interfaces.
  1019   InstanceKlass* ik = InstanceKlass::cast(this);
  1020   Array<Klass*>* interfaces = ik->transitive_interfaces();
  1021   int num_secondaries = num_extra_slots + interfaces->length();
  1022   if (num_secondaries == 0) {
  1023     // Must share this for correct bootstrapping!
  1024     set_secondary_supers(Universe::the_empty_klass_array());
  1025     return NULL;
  1026   } else if (num_extra_slots == 0) {
  1027     // The secondary super list is exactly the same as the transitive interfaces.
  1028     // Redefine classes has to be careful not to delete this!
  1029     set_secondary_supers(interfaces);
  1030     return NULL;
  1031   } else {
  1032     // Copy transitive interfaces to a temporary growable array to be constructed
  1033     // into the secondary super list with extra slots.
  1034     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
  1035     for (int i = 0; i < interfaces->length(); i++) {
  1036       secondaries->push(interfaces->at(i));
  1038     return secondaries;
  1042 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
  1043   if (k->is_interface()) {
  1044     return implements_interface(k);
  1045   } else {
  1046     return Klass::compute_is_subtype_of(k);
  1050 bool InstanceKlass::implements_interface(Klass* k) const {
  1051   if (this == k) return true;
  1052   assert(k->is_interface(), "should be an interface class");
  1053   for (int i = 0; i < transitive_interfaces()->length(); i++) {
  1054     if (transitive_interfaces()->at(i) == k) {
  1055       return true;
  1058   return false;
  1061 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
  1062   // Verify direct super interface
  1063   if (this == k) return true;
  1064   assert(k->is_interface(), "should be an interface class");
  1065   for (int i = 0; i < local_interfaces()->length(); i++) {
  1066     if (local_interfaces()->at(i) == k) {
  1067       return true;
  1070   return false;
  1073 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
  1074   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
  1075   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
  1076     report_java_out_of_memory("Requested array size exceeds VM limit");
  1077     JvmtiExport::post_array_size_exhausted();
  1078     THROW_OOP_0(Universe::out_of_memory_error_array_size());
  1080   int size = objArrayOopDesc::object_size(length);
  1081   Klass* ak = array_klass(n, CHECK_NULL);
  1082   KlassHandle h_ak (THREAD, ak);
  1083   objArrayOop o =
  1084     (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
  1085   return o;
  1088 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
  1089   if (TraceFinalizerRegistration) {
  1090     tty->print("Registered ");
  1091     i->print_value_on(tty);
  1092     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
  1094   instanceHandle h_i(THREAD, i);
  1095   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
  1096   JavaValue result(T_VOID);
  1097   JavaCallArguments args(h_i);
  1098   methodHandle mh (THREAD, Universe::finalizer_register_method());
  1099   JavaCalls::call(&result, mh, &args, CHECK_NULL);
  1100   return h_i();
  1103 instanceOop InstanceKlass::allocate_instance(TRAPS) {
  1104   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
  1105   int size = size_helper();  // Query before forming handle.
  1107   KlassHandle h_k(THREAD, this);
  1109   instanceOop i;
  1111   i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
  1112   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
  1113     i = register_finalizer(i, CHECK_NULL);
  1115   return i;
  1118 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
  1119   if (is_interface() || is_abstract()) {
  1120     ResourceMark rm(THREAD);
  1121     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
  1122               : vmSymbols::java_lang_InstantiationException(), external_name());
  1124   if (this == SystemDictionary::Class_klass()) {
  1125     ResourceMark rm(THREAD);
  1126     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
  1127               : vmSymbols::java_lang_IllegalAccessException(), external_name());
  1131 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
  1132   instanceKlassHandle this_oop(THREAD, this);
  1133   return array_klass_impl(this_oop, or_null, n, THREAD);
  1136 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
  1137   if (this_oop->array_klasses() == NULL) {
  1138     if (or_null) return NULL;
  1140     ResourceMark rm;
  1141     JavaThread *jt = (JavaThread *)THREAD;
  1143       // Atomic creation of array_klasses
  1144       MutexLocker mc(Compile_lock, THREAD);   // for vtables
  1145       MutexLocker ma(MultiArray_lock, THREAD);
  1147       // Check if update has already taken place
  1148       if (this_oop->array_klasses() == NULL) {
  1149         Klass*    k = ObjArrayKlass::allocate_objArray_klass(this_oop->class_loader_data(), 1, this_oop, CHECK_NULL);
  1150         this_oop->set_array_klasses(k);
  1154   // _this will always be set at this point
  1155   ObjArrayKlass* oak = (ObjArrayKlass*)this_oop->array_klasses();
  1156   if (or_null) {
  1157     return oak->array_klass_or_null(n);
  1159   return oak->array_klass(n, CHECK_NULL);
  1162 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
  1163   return array_klass_impl(or_null, 1, THREAD);
  1166 void InstanceKlass::call_class_initializer(TRAPS) {
  1167   instanceKlassHandle ik (THREAD, this);
  1168   call_class_initializer_impl(ik, THREAD);
  1171 static int call_class_initializer_impl_counter = 0;   // for debugging
  1173 Method* InstanceKlass::class_initializer() {
  1174   Method* clinit = find_method(
  1175       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
  1176   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
  1177     return clinit;
  1179   return NULL;
  1182 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
  1183   if (ReplayCompiles &&
  1184       (ReplaySuppressInitializers == 1 ||
  1185        ReplaySuppressInitializers >= 2 && this_oop->class_loader() != NULL)) {
  1186     // Hide the existence of the initializer for the purpose of replaying the compile
  1187     return;
  1190   methodHandle h_method(THREAD, this_oop->class_initializer());
  1191   assert(!this_oop->is_initialized(), "we cannot initialize twice");
  1192   if (TraceClassInitialization) {
  1193     tty->print("%d Initializing ", call_class_initializer_impl_counter++);
  1194     this_oop->name()->print_value();
  1195     tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
  1197   if (h_method() != NULL) {
  1198     JavaCallArguments args; // No arguments
  1199     JavaValue result(T_VOID);
  1200     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
  1205 void InstanceKlass::mask_for(methodHandle method, int bci,
  1206   InterpreterOopMap* entry_for) {
  1207   // Dirty read, then double-check under a lock.
  1208   if (_oop_map_cache == NULL) {
  1209     // Otherwise, allocate a new one.
  1210     MutexLocker x(OopMapCacheAlloc_lock);
  1211     // First time use. Allocate a cache in C heap
  1212     if (_oop_map_cache == NULL) {
  1213       // Release stores from OopMapCache constructor before assignment
  1214       // to _oop_map_cache. C++ compilers on ppc do not emit the
  1215       // required memory barrier only because of the volatile
  1216       // qualifier of _oop_map_cache.
  1217       OrderAccess::release_store_ptr(&_oop_map_cache, new OopMapCache());
  1220   // _oop_map_cache is constant after init; lookup below does is own locking.
  1221   _oop_map_cache->lookup(method, bci, entry_for);
  1225 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  1226   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
  1227     Symbol* f_name = fs.name();
  1228     Symbol* f_sig  = fs.signature();
  1229     if (f_name == name && f_sig == sig) {
  1230       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
  1231       return true;
  1234   return false;
  1238 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  1239   const int n = local_interfaces()->length();
  1240   for (int i = 0; i < n; i++) {
  1241     Klass* intf1 = local_interfaces()->at(i);
  1242     assert(intf1->is_interface(), "just checking type");
  1243     // search for field in current interface
  1244     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
  1245       assert(fd->is_static(), "interface field must be static");
  1246       return intf1;
  1248     // search for field in direct superinterfaces
  1249     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
  1250     if (intf2 != NULL) return intf2;
  1252   // otherwise field lookup fails
  1253   return NULL;
  1257 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  1258   // search order according to newest JVM spec (5.4.3.2, p.167).
  1259   // 1) search for field in current klass
  1260   if (find_local_field(name, sig, fd)) {
  1261     return const_cast<InstanceKlass*>(this);
  1263   // 2) search for field recursively in direct superinterfaces
  1264   { Klass* intf = find_interface_field(name, sig, fd);
  1265     if (intf != NULL) return intf;
  1267   // 3) apply field lookup recursively if superclass exists
  1268   { Klass* supr = super();
  1269     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
  1271   // 4) otherwise field lookup fails
  1272   return NULL;
  1276 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
  1277   // search order according to newest JVM spec (5.4.3.2, p.167).
  1278   // 1) search for field in current klass
  1279   if (find_local_field(name, sig, fd)) {
  1280     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
  1282   // 2) search for field recursively in direct superinterfaces
  1283   if (is_static) {
  1284     Klass* intf = find_interface_field(name, sig, fd);
  1285     if (intf != NULL) return intf;
  1287   // 3) apply field lookup recursively if superclass exists
  1288   { Klass* supr = super();
  1289     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
  1291   // 4) otherwise field lookup fails
  1292   return NULL;
  1296 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
  1297   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
  1298     if (fs.offset() == offset) {
  1299       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
  1300       if (fd->is_static() == is_static) return true;
  1303   return false;
  1307 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
  1308   Klass* klass = const_cast<InstanceKlass*>(this);
  1309   while (klass != NULL) {
  1310     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
  1311       return true;
  1313     klass = klass->super();
  1315   return false;
  1319 void InstanceKlass::methods_do(void f(Method* method)) {
  1320   int len = methods()->length();
  1321   for (int index = 0; index < len; index++) {
  1322     Method* m = methods()->at(index);
  1323     assert(m->is_method(), "must be method");
  1324     f(m);
  1329 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
  1330   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
  1331     if (fs.access_flags().is_static()) {
  1332       fieldDescriptor& fd = fs.field_descriptor();
  1333       cl->do_field(&fd);
  1339 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
  1340   instanceKlassHandle h_this(THREAD, this);
  1341   do_local_static_fields_impl(h_this, f, mirror, CHECK);
  1345 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_k,
  1346                              void f(fieldDescriptor* fd, Handle mirror, TRAPS), Handle mirror, TRAPS) {
  1347   for (JavaFieldStream fs(this_k()); !fs.done(); fs.next()) {
  1348     if (fs.access_flags().is_static()) {
  1349       fieldDescriptor& fd = fs.field_descriptor();
  1350       f(&fd, mirror, CHECK);
  1356 static int compare_fields_by_offset(int* a, int* b) {
  1357   return a[0] - b[0];
  1360 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
  1361   InstanceKlass* super = superklass();
  1362   if (super != NULL) {
  1363     super->do_nonstatic_fields(cl);
  1365   fieldDescriptor fd;
  1366   int length = java_fields_count();
  1367   // In DebugInfo nonstatic fields are sorted by offset.
  1368   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
  1369   int j = 0;
  1370   for (int i = 0; i < length; i += 1) {
  1371     fd.reinitialize(this, i);
  1372     if (!fd.is_static()) {
  1373       fields_sorted[j + 0] = fd.offset();
  1374       fields_sorted[j + 1] = i;
  1375       j += 2;
  1378   if (j > 0) {
  1379     length = j;
  1380     // _sort_Fn is defined in growableArray.hpp.
  1381     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
  1382     for (int i = 0; i < length; i += 2) {
  1383       fd.reinitialize(this, fields_sorted[i + 1]);
  1384       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
  1385       cl->do_field(&fd);
  1388   FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
  1392 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
  1393   if (array_klasses() != NULL)
  1394     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
  1397 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
  1398   if (array_klasses() != NULL)
  1399     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
  1402 #ifdef ASSERT
  1403 static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
  1404   int len = methods->length();
  1405   for (int index = 0; index < len; index++) {
  1406     Method* m = methods->at(index);
  1407     assert(m->is_method(), "must be method");
  1408     if (m->signature() == signature && m->name() == name) {
  1409        return index;
  1412   return -1;
  1414 #endif
  1416 static int binary_search(Array<Method*>* methods, Symbol* name) {
  1417   int len = methods->length();
  1418   // methods are sorted, so do binary search
  1419   int l = 0;
  1420   int h = len - 1;
  1421   while (l <= h) {
  1422     int mid = (l + h) >> 1;
  1423     Method* m = methods->at(mid);
  1424     assert(m->is_method(), "must be method");
  1425     int res = m->name()->fast_compare(name);
  1426     if (res == 0) {
  1427       return mid;
  1428     } else if (res < 0) {
  1429       l = mid + 1;
  1430     } else {
  1431       h = mid - 1;
  1434   return -1;
  1437 // find_method looks up the name/signature in the local methods array
  1438 Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
  1439   return find_method_impl(name, signature, false);
  1442 Method* InstanceKlass::find_method_impl(Symbol* name, Symbol* signature, bool skipping_overpass) const {
  1443   return InstanceKlass::find_method_impl(methods(), name, signature, skipping_overpass);
  1446 // find_instance_method looks up the name/signature in the local methods array
  1447 // and skips over static methods
  1448 Method* InstanceKlass::find_instance_method(
  1449     Array<Method*>* methods, Symbol* name, Symbol* signature) {
  1450   Method* meth = InstanceKlass::find_method(methods, name, signature);
  1451   if (meth != NULL && meth->is_static()) {
  1452       meth = NULL;
  1454   return meth;
  1457 // find_method looks up the name/signature in the local methods array
  1458 Method* InstanceKlass::find_method(
  1459     Array<Method*>* methods, Symbol* name, Symbol* signature) {
  1460   return InstanceKlass::find_method_impl(methods, name, signature, false);
  1463 Method* InstanceKlass::find_method_impl(
  1464     Array<Method*>* methods, Symbol* name, Symbol* signature, bool skipping_overpass) {
  1465   int hit = find_method_index(methods, name, signature, skipping_overpass);
  1466   return hit >= 0 ? methods->at(hit): NULL;
  1469 // Used directly for default_methods to find the index into the
  1470 // default_vtable_indices, and indirectly by find_method
  1471 // find_method_index looks in the local methods array to return the index
  1472 // of the matching name/signature. If, overpass methods are being ignored,
  1473 // the search continues to find a potential non-overpass match.  This capability
  1474 // is important during method resolution to prefer a static method, for example,
  1475 // over an overpass method.
  1476 int InstanceKlass::find_method_index(
  1477     Array<Method*>* methods, Symbol* name, Symbol* signature, bool skipping_overpass) {
  1478   int hit = binary_search(methods, name);
  1479   if (hit != -1) {
  1480     Method* m = methods->at(hit);
  1481     // Do linear search to find matching signature.  First, quick check
  1482     // for common case, ignoring overpasses if requested.
  1483     if ((m->signature() == signature) && (!skipping_overpass || !m->is_overpass())) return hit;
  1485     // search downwards through overloaded methods
  1486     int i;
  1487     for (i = hit - 1; i >= 0; --i) {
  1488         Method* m = methods->at(i);
  1489         assert(m->is_method(), "must be method");
  1490         if (m->name() != name) break;
  1491         if ((m->signature() == signature) && (!skipping_overpass || !m->is_overpass())) return i;
  1493     // search upwards
  1494     for (i = hit + 1; i < methods->length(); ++i) {
  1495         Method* m = methods->at(i);
  1496         assert(m->is_method(), "must be method");
  1497         if (m->name() != name) break;
  1498         if ((m->signature() == signature) && (!skipping_overpass || !m->is_overpass())) return i;
  1500     // not found
  1501 #ifdef ASSERT
  1502     int index = skipping_overpass ? -1 : linear_search(methods, name, signature);
  1503     assert(index == -1, err_msg("binary search should have found entry %d", index));
  1504 #endif
  1506   return -1;
  1508 int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
  1509   return find_method_by_name(methods(), name, end);
  1512 int InstanceKlass::find_method_by_name(
  1513     Array<Method*>* methods, Symbol* name, int* end_ptr) {
  1514   assert(end_ptr != NULL, "just checking");
  1515   int start = binary_search(methods, name);
  1516   int end = start + 1;
  1517   if (start != -1) {
  1518     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
  1519     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
  1520     *end_ptr = end;
  1521     return start;
  1523   return -1;
  1526 // uncached_lookup_method searches both the local class methods array and all
  1527 // superclasses methods arrays, skipping any overpass methods in superclasses.
  1528 Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature, MethodLookupMode mode) const {
  1529   MethodLookupMode lookup_mode = mode;
  1530   Klass* klass = const_cast<InstanceKlass*>(this);
  1531   while (klass != NULL) {
  1532     Method* method = InstanceKlass::cast(klass)->find_method_impl(name, signature, (lookup_mode == skip_overpass));
  1533     if (method != NULL) {
  1534       return method;
  1536     klass = InstanceKlass::cast(klass)->super();
  1537     lookup_mode = skip_overpass;   // Always ignore overpass methods in superclasses
  1539   return NULL;
  1542 // lookup a method in the default methods list then in all transitive interfaces
  1543 // Do NOT return private or static methods
  1544 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
  1545                                                          Symbol* signature) const {
  1546   Method* m = NULL;
  1547   if (default_methods() != NULL) {
  1548     m = find_method(default_methods(), name, signature);
  1550   // Look up interfaces
  1551   if (m == NULL) {
  1552     m = lookup_method_in_all_interfaces(name, signature, normal);
  1554   return m;
  1557 // lookup a method in all the interfaces that this class implements
  1558 // Do NOT return private or static methods, new in JDK8 which are not externally visible
  1559 // They should only be found in the initial InterfaceMethodRef
  1560 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
  1561                                                        Symbol* signature,
  1562                                                        MethodLookupMode mode) const {
  1563   Array<Klass*>* all_ifs = transitive_interfaces();
  1564   int num_ifs = all_ifs->length();
  1565   InstanceKlass *ik = NULL;
  1566   for (int i = 0; i < num_ifs; i++) {
  1567     ik = InstanceKlass::cast(all_ifs->at(i));
  1568     Method* m = ik->lookup_method(name, signature);
  1569     if (m != NULL && m->is_public() && !m->is_static() &&
  1570         ((mode != skip_defaults) || !m->is_default_method())) {
  1571       return m;
  1574   return NULL;
  1577 /* jni_id_for_impl for jfieldIds only */
  1578 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
  1579   MutexLocker ml(JfieldIdCreation_lock);
  1580   // Retry lookup after we got the lock
  1581   JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
  1582   if (probe == NULL) {
  1583     // Slow case, allocate new static field identifier
  1584     probe = new JNIid(this_oop(), offset, this_oop->jni_ids());
  1585     this_oop->set_jni_ids(probe);
  1587   return probe;
  1591 /* jni_id_for for jfieldIds only */
  1592 JNIid* InstanceKlass::jni_id_for(int offset) {
  1593   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
  1594   if (probe == NULL) {
  1595     probe = jni_id_for_impl(this, offset);
  1597   return probe;
  1600 u2 InstanceKlass::enclosing_method_data(int offset) {
  1601   Array<jushort>* inner_class_list = inner_classes();
  1602   if (inner_class_list == NULL) {
  1603     return 0;
  1605   int length = inner_class_list->length();
  1606   if (length % inner_class_next_offset == 0) {
  1607     return 0;
  1608   } else {
  1609     int index = length - enclosing_method_attribute_size;
  1610     assert(offset < enclosing_method_attribute_size, "invalid offset");
  1611     return inner_class_list->at(index + offset);
  1615 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
  1616                                                  u2 method_index) {
  1617   Array<jushort>* inner_class_list = inner_classes();
  1618   assert (inner_class_list != NULL, "_inner_classes list is not set up");
  1619   int length = inner_class_list->length();
  1620   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
  1621     int index = length - enclosing_method_attribute_size;
  1622     inner_class_list->at_put(
  1623       index + enclosing_method_class_index_offset, class_index);
  1624     inner_class_list->at_put(
  1625       index + enclosing_method_method_index_offset, method_index);
  1629 // Lookup or create a jmethodID.
  1630 // This code is called by the VMThread and JavaThreads so the
  1631 // locking has to be done very carefully to avoid deadlocks
  1632 // and/or other cache consistency problems.
  1633 //
  1634 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
  1635   size_t idnum = (size_t)method_h->method_idnum();
  1636   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
  1637   size_t length = 0;
  1638   jmethodID id = NULL;
  1640   // We use a double-check locking idiom here because this cache is
  1641   // performance sensitive. In the normal system, this cache only
  1642   // transitions from NULL to non-NULL which is safe because we use
  1643   // release_set_methods_jmethod_ids() to advertise the new cache.
  1644   // A partially constructed cache should never be seen by a racing
  1645   // thread. We also use release_store_ptr() to save a new jmethodID
  1646   // in the cache so a partially constructed jmethodID should never be
  1647   // seen either. Cache reads of existing jmethodIDs proceed without a
  1648   // lock, but cache writes of a new jmethodID requires uniqueness and
  1649   // creation of the cache itself requires no leaks so a lock is
  1650   // generally acquired in those two cases.
  1651   //
  1652   // If the RedefineClasses() API has been used, then this cache can
  1653   // grow and we'll have transitions from non-NULL to bigger non-NULL.
  1654   // Cache creation requires no leaks and we require safety between all
  1655   // cache accesses and freeing of the old cache so a lock is generally
  1656   // acquired when the RedefineClasses() API has been used.
  1658   if (jmeths != NULL) {
  1659     // the cache already exists
  1660     if (!ik_h->idnum_can_increment()) {
  1661       // the cache can't grow so we can just get the current values
  1662       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1663     } else {
  1664       // cache can grow so we have to be more careful
  1665       if (Threads::number_of_threads() == 0 ||
  1666           SafepointSynchronize::is_at_safepoint()) {
  1667         // we're single threaded or at a safepoint - no locking needed
  1668         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1669       } else {
  1670         MutexLocker ml(JmethodIdCreation_lock);
  1671         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1675   // implied else:
  1676   // we need to allocate a cache so default length and id values are good
  1678   if (jmeths == NULL ||   // no cache yet
  1679       length <= idnum ||  // cache is too short
  1680       id == NULL) {       // cache doesn't contain entry
  1682     // This function can be called by the VMThread so we have to do all
  1683     // things that might block on a safepoint before grabbing the lock.
  1684     // Otherwise, we can deadlock with the VMThread or have a cache
  1685     // consistency issue. These vars keep track of what we might have
  1686     // to free after the lock is dropped.
  1687     jmethodID  to_dealloc_id     = NULL;
  1688     jmethodID* to_dealloc_jmeths = NULL;
  1690     // may not allocate new_jmeths or use it if we allocate it
  1691     jmethodID* new_jmeths = NULL;
  1692     if (length <= idnum) {
  1693       // allocate a new cache that might be used
  1694       size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
  1695       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
  1696       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
  1697       // cache size is stored in element[0], other elements offset by one
  1698       new_jmeths[0] = (jmethodID)size;
  1701     // allocate a new jmethodID that might be used
  1702     jmethodID new_id = NULL;
  1703     if (method_h->is_old() && !method_h->is_obsolete()) {
  1704       // The method passed in is old (but not obsolete), we need to use the current version
  1705       Method* current_method = ik_h->method_with_idnum((int)idnum);
  1706       assert(current_method != NULL, "old and but not obsolete, so should exist");
  1707       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
  1708     } else {
  1709       // It is the current version of the method or an obsolete method,
  1710       // use the version passed in
  1711       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
  1714     if (Threads::number_of_threads() == 0 ||
  1715         SafepointSynchronize::is_at_safepoint()) {
  1716       // we're single threaded or at a safepoint - no locking needed
  1717       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
  1718                                           &to_dealloc_id, &to_dealloc_jmeths);
  1719     } else {
  1720       MutexLocker ml(JmethodIdCreation_lock);
  1721       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
  1722                                           &to_dealloc_id, &to_dealloc_jmeths);
  1725     // The lock has been dropped so we can free resources.
  1726     // Free up either the old cache or the new cache if we allocated one.
  1727     if (to_dealloc_jmeths != NULL) {
  1728       FreeHeap(to_dealloc_jmeths);
  1730     // free up the new ID since it wasn't needed
  1731     if (to_dealloc_id != NULL) {
  1732       Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
  1735   return id;
  1739 // Common code to fetch the jmethodID from the cache or update the
  1740 // cache with the new jmethodID. This function should never do anything
  1741 // that causes the caller to go to a safepoint or we can deadlock with
  1742 // the VMThread or have cache consistency issues.
  1743 //
  1744 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
  1745             instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
  1746             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
  1747             jmethodID** to_dealloc_jmeths_p) {
  1748   assert(new_id != NULL, "sanity check");
  1749   assert(to_dealloc_id_p != NULL, "sanity check");
  1750   assert(to_dealloc_jmeths_p != NULL, "sanity check");
  1751   assert(Threads::number_of_threads() == 0 ||
  1752          SafepointSynchronize::is_at_safepoint() ||
  1753          JmethodIdCreation_lock->owned_by_self(), "sanity check");
  1755   // reacquire the cache - we are locked, single threaded or at a safepoint
  1756   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
  1757   jmethodID  id     = NULL;
  1758   size_t     length = 0;
  1760   if (jmeths == NULL ||                         // no cache yet
  1761       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
  1762     if (jmeths != NULL) {
  1763       // copy any existing entries from the old cache
  1764       for (size_t index = 0; index < length; index++) {
  1765         new_jmeths[index+1] = jmeths[index+1];
  1767       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
  1769     ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
  1770   } else {
  1771     // fetch jmethodID (if any) from the existing cache
  1772     id = jmeths[idnum+1];
  1773     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
  1775   if (id == NULL) {
  1776     // No matching jmethodID in the existing cache or we have a new
  1777     // cache or we just grew the cache. This cache write is done here
  1778     // by the first thread to win the foot race because a jmethodID
  1779     // needs to be unique once it is generally available.
  1780     id = new_id;
  1782     // The jmethodID cache can be read while unlocked so we have to
  1783     // make sure the new jmethodID is complete before installing it
  1784     // in the cache.
  1785     OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
  1786   } else {
  1787     *to_dealloc_id_p = new_id; // save new id for later delete
  1789   return id;
  1793 // Common code to get the jmethodID cache length and the jmethodID
  1794 // value at index idnum if there is one.
  1795 //
  1796 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
  1797        size_t idnum, size_t *length_p, jmethodID* id_p) {
  1798   assert(cache != NULL, "sanity check");
  1799   assert(length_p != NULL, "sanity check");
  1800   assert(id_p != NULL, "sanity check");
  1802   // cache size is stored in element[0], other elements offset by one
  1803   *length_p = (size_t)cache[0];
  1804   if (*length_p <= idnum) {  // cache is too short
  1805     *id_p = NULL;
  1806   } else {
  1807     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
  1812 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
  1813 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
  1814   size_t idnum = (size_t)method->method_idnum();
  1815   jmethodID* jmeths = methods_jmethod_ids_acquire();
  1816   size_t length;                                // length assigned as debugging crumb
  1817   jmethodID id = NULL;
  1818   if (jmeths != NULL &&                         // If there is a cache
  1819       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
  1820     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
  1822   return id;
  1825 int nmethodBucket::decrement() {
  1826   return Atomic::add(-1, (volatile int *)&_count);
  1829 //
  1830 // Walk the list of dependent nmethods searching for nmethods which
  1831 // are dependent on the changes that were passed in and mark them for
  1832 // deoptimization.  Returns the number of nmethods found.
  1833 //
  1834 int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
  1835   assert_locked_or_safepoint(CodeCache_lock);
  1836   int found = 0;
  1837   nmethodBucket* b = _dependencies;
  1838   while (b != NULL) {
  1839     nmethod* nm = b->get_nmethod();
  1840     // since dependencies aren't removed until an nmethod becomes a zombie,
  1841     // the dependency list may contain nmethods which aren't alive.
  1842     if (b->count() > 0 && nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
  1843       if (TraceDependencies) {
  1844         ResourceMark rm;
  1845         tty->print_cr("Marked for deoptimization");
  1846         tty->print_cr("  context = %s", this->external_name());
  1847         changes.print();
  1848         nm->print();
  1849         nm->print_dependencies();
  1851       nm->mark_for_deoptimization();
  1852       found++;
  1854     b = b->next();
  1856   return found;
  1859 void InstanceKlass::clean_dependent_nmethods() {
  1860   assert_locked_or_safepoint(CodeCache_lock);
  1862   if (has_unloaded_dependent()) {
  1863     nmethodBucket* b = _dependencies;
  1864     nmethodBucket* last = NULL;
  1865     while (b != NULL) {
  1866       assert(b->count() >= 0, err_msg("bucket count: %d", b->count()));
  1868       nmethodBucket* next = b->next();
  1870       if (b->count() == 0) {
  1871         if (last == NULL) {
  1872           _dependencies = next;
  1873         } else {
  1874           last->set_next(next);
  1876         delete b;
  1877         // last stays the same.
  1878       } else {
  1879         last = b;
  1882       b = next;
  1884     set_has_unloaded_dependent(false);
  1886 #ifdef ASSERT
  1887   else {
  1888     // Verification
  1889     for (nmethodBucket* b = _dependencies; b != NULL; b = b->next()) {
  1890       assert(b->count() >= 0, err_msg("bucket count: %d", b->count()));
  1891       assert(b->count() != 0, "empty buckets need to be cleaned");
  1894 #endif
  1897 //
  1898 // Add an nmethodBucket to the list of dependencies for this nmethod.
  1899 // It's possible that an nmethod has multiple dependencies on this klass
  1900 // so a count is kept for each bucket to guarantee that creation and
  1901 // deletion of dependencies is consistent.
  1902 //
  1903 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
  1904   assert_locked_or_safepoint(CodeCache_lock);
  1905   nmethodBucket* b = _dependencies;
  1906   nmethodBucket* last = NULL;
  1907   while (b != NULL) {
  1908     if (nm == b->get_nmethod()) {
  1909       b->increment();
  1910       return;
  1912     b = b->next();
  1914   _dependencies = new nmethodBucket(nm, _dependencies);
  1918 //
  1919 // Decrement count of the nmethod in the dependency list and remove
  1920 // the bucket competely when the count goes to 0.  This method must
  1921 // find a corresponding bucket otherwise there's a bug in the
  1922 // recording of dependecies.
  1923 //
  1924 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
  1925   assert_locked_or_safepoint(CodeCache_lock);
  1926   nmethodBucket* b = _dependencies;
  1927   nmethodBucket* last = NULL;
  1928   while (b != NULL) {
  1929     if (nm == b->get_nmethod()) {
  1930       int val = b->decrement();
  1931       guarantee(val >= 0, err_msg("Underflow: %d", val));
  1932       if (val == 0) {
  1933         set_has_unloaded_dependent(true);
  1935       return;
  1937     last = b;
  1938     b = b->next();
  1940 #ifdef ASSERT
  1941   tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
  1942   nm->print();
  1943 #endif // ASSERT
  1944   ShouldNotReachHere();
  1948 #ifndef PRODUCT
  1949 void InstanceKlass::print_dependent_nmethods(bool verbose) {
  1950   nmethodBucket* b = _dependencies;
  1951   int idx = 0;
  1952   while (b != NULL) {
  1953     nmethod* nm = b->get_nmethod();
  1954     tty->print("[%d] count=%d { ", idx++, b->count());
  1955     if (!verbose) {
  1956       nm->print_on(tty, "nmethod");
  1957       tty->print_cr(" } ");
  1958     } else {
  1959       nm->print();
  1960       nm->print_dependencies();
  1961       tty->print_cr("--- } ");
  1963     b = b->next();
  1968 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
  1969   nmethodBucket* b = _dependencies;
  1970   while (b != NULL) {
  1971     if (nm == b->get_nmethod()) {
  1972 #ifdef ASSERT
  1973       int count = b->count();
  1974       assert(count >= 0, err_msg("count shouldn't be negative: %d", count));
  1975 #endif
  1976       return true;
  1978     b = b->next();
  1980   return false;
  1982 #endif //PRODUCT
  1985 // Garbage collection
  1987 #ifdef ASSERT
  1988 template <class T> void assert_is_in(T *p) {
  1989   T heap_oop = oopDesc::load_heap_oop(p);
  1990   if (!oopDesc::is_null(heap_oop)) {
  1991     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1992     assert(Universe::heap()->is_in(o), "should be in heap");
  1995 template <class T> void assert_is_in_closed_subset(T *p) {
  1996   T heap_oop = oopDesc::load_heap_oop(p);
  1997   if (!oopDesc::is_null(heap_oop)) {
  1998     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1999     assert(Universe::heap()->is_in_closed_subset(o),
  2000            err_msg("should be in closed *p " INTPTR_FORMAT " " INTPTR_FORMAT, (address)p, (address)o));
  2003 template <class T> void assert_is_in_reserved(T *p) {
  2004   T heap_oop = oopDesc::load_heap_oop(p);
  2005   if (!oopDesc::is_null(heap_oop)) {
  2006     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  2007     assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
  2010 template <class T> void assert_nothing(T *p) {}
  2012 #else
  2013 template <class T> void assert_is_in(T *p) {}
  2014 template <class T> void assert_is_in_closed_subset(T *p) {}
  2015 template <class T> void assert_is_in_reserved(T *p) {}
  2016 template <class T> void assert_nothing(T *p) {}
  2017 #endif // ASSERT
  2019 //
  2020 // Macros that iterate over areas of oops which are specialized on type of
  2021 // oop pointer either narrow or wide, depending on UseCompressedOops
  2022 //
  2023 // Parameters are:
  2024 //   T         - type of oop to point to (either oop or narrowOop)
  2025 //   start_p   - starting pointer for region to iterate over
  2026 //   count     - number of oops or narrowOops to iterate over
  2027 //   do_oop    - action to perform on each oop (it's arbitrary C code which
  2028 //               makes it more efficient to put in a macro rather than making
  2029 //               it a template function)
  2030 //   assert_fn - assert function which is template function because performance
  2031 //               doesn't matter when enabled.
  2032 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
  2033   T, start_p, count, do_oop,                \
  2034   assert_fn)                                \
  2035 {                                           \
  2036   T* p         = (T*)(start_p);             \
  2037   T* const end = p + (count);               \
  2038   while (p < end) {                         \
  2039     (assert_fn)(p);                         \
  2040     do_oop;                                 \
  2041     ++p;                                    \
  2042   }                                         \
  2045 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
  2046   T, start_p, count, do_oop,                \
  2047   assert_fn)                                \
  2048 {                                           \
  2049   T* const start = (T*)(start_p);           \
  2050   T*       p     = start + (count);         \
  2051   while (start < p) {                       \
  2052     --p;                                    \
  2053     (assert_fn)(p);                         \
  2054     do_oop;                                 \
  2055   }                                         \
  2058 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
  2059   T, start_p, count, low, high,             \
  2060   do_oop, assert_fn)                        \
  2061 {                                           \
  2062   T* const l = (T*)(low);                   \
  2063   T* const h = (T*)(high);                  \
  2064   assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
  2065          mask_bits((intptr_t)h, sizeof(T)-1) == 0,   \
  2066          "bounded region must be properly aligned"); \
  2067   T* p       = (T*)(start_p);               \
  2068   T* end     = p + (count);                 \
  2069   if (p < l) p = l;                         \
  2070   if (end > h) end = h;                     \
  2071   while (p < end) {                         \
  2072     (assert_fn)(p);                         \
  2073     do_oop;                                 \
  2074     ++p;                                    \
  2075   }                                         \
  2079 // The following macros call specialized macros, passing either oop or
  2080 // narrowOop as the specialization type.  These test the UseCompressedOops
  2081 // flag.
  2082 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn)            \
  2083 {                                                                        \
  2084   /* Compute oopmap block range. The common case                         \
  2085      is nonstatic_oop_map_size == 1. */                                  \
  2086   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  2087   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
  2088   if (UseCompressedOops) {                                               \
  2089     while (map < end_map) {                                              \
  2090       InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop,                   \
  2091         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  2092         do_oop, assert_fn)                                               \
  2093       ++map;                                                             \
  2094     }                                                                    \
  2095   } else {                                                               \
  2096     while (map < end_map) {                                              \
  2097       InstanceKlass_SPECIALIZED_OOP_ITERATE(oop,                         \
  2098         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  2099         do_oop, assert_fn)                                               \
  2100       ++map;                                                             \
  2101     }                                                                    \
  2102   }                                                                      \
  2105 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn)    \
  2106 {                                                                        \
  2107   OopMapBlock* const start_map = start_of_nonstatic_oop_maps();          \
  2108   OopMapBlock* map             = start_map + nonstatic_oop_map_count();  \
  2109   if (UseCompressedOops) {                                               \
  2110     while (start_map < map) {                                            \
  2111       --map;                                                             \
  2112       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop,           \
  2113         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  2114         do_oop, assert_fn)                                               \
  2115     }                                                                    \
  2116   } else {                                                               \
  2117     while (start_map < map) {                                            \
  2118       --map;                                                             \
  2119       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop,                 \
  2120         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  2121         do_oop, assert_fn)                                               \
  2122     }                                                                    \
  2123   }                                                                      \
  2126 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop,    \
  2127                                               assert_fn)                 \
  2128 {                                                                        \
  2129   /* Compute oopmap block range. The common case is                      \
  2130      nonstatic_oop_map_size == 1, so we accept the                       \
  2131      usually non-existent extra overhead of examining                    \
  2132      all the maps. */                                                    \
  2133   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  2134   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
  2135   if (UseCompressedOops) {                                               \
  2136     while (map < end_map) {                                              \
  2137       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop,           \
  2138         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  2139         low, high,                                                       \
  2140         do_oop, assert_fn)                                               \
  2141       ++map;                                                             \
  2142     }                                                                    \
  2143   } else {                                                               \
  2144     while (map < end_map) {                                              \
  2145       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop,                 \
  2146         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  2147         low, high,                                                       \
  2148         do_oop, assert_fn)                                               \
  2149       ++map;                                                             \
  2150     }                                                                    \
  2151   }                                                                      \
  2154 void InstanceKlass::oop_follow_contents(oop obj) {
  2155   assert(obj != NULL, "can't follow the content of NULL object");
  2156   MarkSweep::follow_klass(obj->klass());
  2157   InstanceKlass_OOP_MAP_ITERATE( \
  2158     obj, \
  2159     MarkSweep::mark_and_push(p), \
  2160     assert_is_in_closed_subset)
  2163 #if INCLUDE_ALL_GCS
  2164 void InstanceKlass::oop_follow_contents(ParCompactionManager* cm,
  2165                                         oop obj) {
  2166   assert(obj != NULL, "can't follow the content of NULL object");
  2167   PSParallelCompact::follow_klass(cm, obj->klass());
  2168   // Only mark the header and let the scan of the meta-data mark
  2169   // everything else.
  2170   InstanceKlass_OOP_MAP_ITERATE( \
  2171     obj, \
  2172     PSParallelCompact::mark_and_push(cm, p), \
  2173     assert_is_in)
  2175 #endif // INCLUDE_ALL_GCS
  2177 // closure's do_metadata() method dictates whether the given closure should be
  2178 // applied to the klass ptr in the object header.
  2180 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)        \
  2182 int InstanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
  2183   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  2184   /* header */                                                          \
  2185   if_do_metadata_checked(closure, nv_suffix) {                          \
  2186     closure->do_klass##nv_suffix(obj->klass());                         \
  2187   }                                                                     \
  2188   InstanceKlass_OOP_MAP_ITERATE(                                        \
  2189     obj,                                                                \
  2190     SpecializationStats::                                               \
  2191       record_do_oop_call##nv_suffix(SpecializationStats::ik);           \
  2192     (closure)->do_oop##nv_suffix(p),                                    \
  2193     assert_is_in_closed_subset)                                         \
  2194   return size_helper();                                                 \
  2197 #if INCLUDE_ALL_GCS
  2198 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
  2200 int InstanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj,                \
  2201                                               OopClosureType* closure) {        \
  2202   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
  2204   assert_should_ignore_metadata(closure, nv_suffix);                            \
  2206   /* instance variables */                                                      \
  2207   InstanceKlass_OOP_MAP_REVERSE_ITERATE(                                        \
  2208     obj,                                                                        \
  2209     SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
  2210     (closure)->do_oop##nv_suffix(p),                                            \
  2211     assert_is_in_closed_subset)                                                 \
  2212    return size_helper();                                                        \
  2214 #endif // INCLUDE_ALL_GCS
  2216 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
  2218 int InstanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj,              \
  2219                                                   OopClosureType* closure, \
  2220                                                   MemRegion mr) {          \
  2221   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  2222   if_do_metadata_checked(closure, nv_suffix) {                           \
  2223     if (mr.contains(obj)) {                                              \
  2224       closure->do_klass##nv_suffix(obj->klass());                        \
  2225     }                                                                    \
  2226   }                                                                      \
  2227   InstanceKlass_BOUNDED_OOP_MAP_ITERATE(                                 \
  2228     obj, mr.start(), mr.end(),                                           \
  2229     (closure)->do_oop##nv_suffix(p),                                     \
  2230     assert_is_in_closed_subset)                                          \
  2231   return size_helper();                                                  \
  2234 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
  2235 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
  2236 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
  2237 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
  2238 #if INCLUDE_ALL_GCS
  2239 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
  2240 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
  2241 #endif // INCLUDE_ALL_GCS
  2243 int InstanceKlass::oop_adjust_pointers(oop obj) {
  2244   int size = size_helper();
  2245   InstanceKlass_OOP_MAP_ITERATE( \
  2246     obj, \
  2247     MarkSweep::adjust_pointer(p), \
  2248     assert_is_in)
  2249   return size;
  2252 #if INCLUDE_ALL_GCS
  2253 void InstanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
  2254   InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
  2255     obj, \
  2256     if (PSScavenge::should_scavenge(p)) { \
  2257       pm->claim_or_forward_depth(p); \
  2258     }, \
  2259     assert_nothing )
  2262 int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
  2263   int size = size_helper();
  2264   InstanceKlass_OOP_MAP_ITERATE( \
  2265     obj, \
  2266     PSParallelCompact::adjust_pointer(p), \
  2267     assert_is_in)
  2268   return size;
  2271 #endif // INCLUDE_ALL_GCS
  2273 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
  2274   assert(class_loader_data()->is_alive(is_alive), "this klass should be live");
  2275   if (is_interface()) {
  2276     if (ClassUnloading) {
  2277       Klass* impl = implementor();
  2278       if (impl != NULL) {
  2279         if (!impl->is_loader_alive(is_alive)) {
  2280           // remove this guy
  2281           Klass** klass = adr_implementor();
  2282           assert(klass != NULL, "null klass");
  2283           if (klass != NULL) {
  2284             *klass = NULL;
  2292 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
  2293   for (int m = 0; m < methods()->length(); m++) {
  2294     MethodData* mdo = methods()->at(m)->method_data();
  2295     if (mdo != NULL) {
  2296       mdo->clean_method_data(is_alive);
  2302 static void remove_unshareable_in_class(Klass* k) {
  2303   // remove klass's unshareable info
  2304   k->remove_unshareable_info();
  2307 void InstanceKlass::remove_unshareable_info() {
  2308   Klass::remove_unshareable_info();
  2309   // Unlink the class
  2310   if (is_linked()) {
  2311     unlink_class();
  2313   init_implementor();
  2315   constants()->remove_unshareable_info();
  2317   for (int i = 0; i < methods()->length(); i++) {
  2318     Method* m = methods()->at(i);
  2319     m->remove_unshareable_info();
  2322   // do array classes also.
  2323   array_klasses_do(remove_unshareable_in_class);
  2326 static void restore_unshareable_in_class(Klass* k, TRAPS) {
  2327   // Array classes have null protection domain.
  2328   // --> see ArrayKlass::complete_create_array_klass()
  2329   k->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
  2332 void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
  2333   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
  2334   instanceKlassHandle ik(THREAD, this);
  2336   Array<Method*>* methods = ik->methods();
  2337   int num_methods = methods->length();
  2338   for (int index2 = 0; index2 < num_methods; ++index2) {
  2339     methodHandle m(THREAD, methods->at(index2));
  2340     m->restore_unshareable_info(CHECK);
  2342   if (JvmtiExport::has_redefined_a_class()) {
  2343     // Reinitialize vtable because RedefineClasses may have changed some
  2344     // entries in this vtable for super classes so the CDS vtable might
  2345     // point to old or obsolete entries.  RedefineClasses doesn't fix up
  2346     // vtables in the shared system dictionary, only the main one.
  2347     // It also redefines the itable too so fix that too.
  2348     ResourceMark rm(THREAD);
  2349     ik->vtable()->initialize_vtable(false, CHECK);
  2350     ik->itable()->initialize_itable(false, CHECK);
  2353   // restore constant pool resolved references
  2354   ik->constants()->restore_unshareable_info(CHECK);
  2356   ik->array_klasses_do(restore_unshareable_in_class, CHECK);
  2359 // returns true IFF is_in_error_state() has been changed as a result of this call.
  2360 bool InstanceKlass::check_sharing_error_state() {
  2361   assert(DumpSharedSpaces, "should only be called during dumping");
  2362   bool old_state = is_in_error_state();
  2364   if (!is_in_error_state()) {
  2365     bool bad = false;
  2366     for (InstanceKlass* sup = java_super(); sup; sup = sup->java_super()) {
  2367       if (sup->is_in_error_state()) {
  2368         bad = true;
  2369         break;
  2372     if (!bad) {
  2373       Array<Klass*>* interfaces = transitive_interfaces();
  2374       for (int i = 0; i < interfaces->length(); i++) {
  2375         Klass* iface = interfaces->at(i);
  2376         if (InstanceKlass::cast(iface)->is_in_error_state()) {
  2377           bad = true;
  2378           break;
  2383     if (bad) {
  2384       set_in_error_state();
  2388   return (old_state != is_in_error_state());
  2391 static void clear_all_breakpoints(Method* m) {
  2392   m->clear_all_breakpoints();
  2396 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
  2397   // notify the debugger
  2398   if (JvmtiExport::should_post_class_unload()) {
  2399     JvmtiExport::post_class_unload(ik);
  2402   // notify ClassLoadingService of class unload
  2403   ClassLoadingService::notify_class_unloaded(ik);
  2406 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
  2407   // Clean up C heap
  2408   ik->release_C_heap_structures();
  2409   ik->constants()->release_C_heap_structures();
  2412 void InstanceKlass::release_C_heap_structures() {
  2414   // Can't release the constant pool here because the constant pool can be
  2415   // deallocated separately from the InstanceKlass for default methods and
  2416   // redefine classes.
  2418   // Deallocate oop map cache
  2419   if (_oop_map_cache != NULL) {
  2420     delete _oop_map_cache;
  2421     _oop_map_cache = NULL;
  2424   // Deallocate JNI identifiers for jfieldIDs
  2425   JNIid::deallocate(jni_ids());
  2426   set_jni_ids(NULL);
  2428   jmethodID* jmeths = methods_jmethod_ids_acquire();
  2429   if (jmeths != (jmethodID*)NULL) {
  2430     release_set_methods_jmethod_ids(NULL);
  2431     FreeHeap(jmeths);
  2434   // Deallocate MemberNameTable
  2436     Mutex* lock_or_null = SafepointSynchronize::is_at_safepoint() ? NULL : MemberNameTable_lock;
  2437     MutexLockerEx ml(lock_or_null, Mutex::_no_safepoint_check_flag);
  2438     MemberNameTable* mnt = member_names();
  2439     if (mnt != NULL) {
  2440       delete mnt;
  2441       set_member_names(NULL);
  2445   // release dependencies
  2446   nmethodBucket* b = _dependencies;
  2447   _dependencies = NULL;
  2448   while (b != NULL) {
  2449     nmethodBucket* next = b->next();
  2450     delete b;
  2451     b = next;
  2454   // Deallocate breakpoint records
  2455   if (breakpoints() != 0x0) {
  2456     methods_do(clear_all_breakpoints);
  2457     assert(breakpoints() == 0x0, "should have cleared breakpoints");
  2460   // deallocate information about previous versions
  2461   if (_previous_versions != NULL) {
  2462     for (int i = _previous_versions->length() - 1; i >= 0; i--) {
  2463       PreviousVersionNode * pv_node = _previous_versions->at(i);
  2464       delete pv_node;
  2466     delete _previous_versions;
  2467     _previous_versions = NULL;
  2470   // deallocate the cached class file
  2471   if (_cached_class_file != NULL) {
  2472     os::free(_cached_class_file, mtClass);
  2473     _cached_class_file = NULL;
  2476   // Decrement symbol reference counts associated with the unloaded class.
  2477   if (_name != NULL) _name->decrement_refcount();
  2478   // unreference array name derived from this class name (arrays of an unloaded
  2479   // class can't be referenced anymore).
  2480   if (_array_name != NULL)  _array_name->decrement_refcount();
  2481   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension, mtClass);
  2483   assert(_total_instanceKlass_count >= 1, "Sanity check");
  2484   Atomic::dec(&_total_instanceKlass_count);
  2487 void InstanceKlass::set_source_debug_extension(char* array, int length) {
  2488   if (array == NULL) {
  2489     _source_debug_extension = NULL;
  2490   } else {
  2491     // Adding one to the attribute length in order to store a null terminator
  2492     // character could cause an overflow because the attribute length is
  2493     // already coded with an u4 in the classfile, but in practice, it's
  2494     // unlikely to happen.
  2495     assert((length+1) > length, "Overflow checking");
  2496     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
  2497     for (int i = 0; i < length; i++) {
  2498       sde[i] = array[i];
  2500     sde[length] = '\0';
  2501     _source_debug_extension = sde;
  2505 address InstanceKlass::static_field_addr(int offset) {
  2506   return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
  2510 const char* InstanceKlass::signature_name() const {
  2511   int hash_len = 0;
  2512   char hash_buf[40];
  2514   // If this is an anonymous class, append a hash to make the name unique
  2515   if (is_anonymous()) {
  2516     assert(EnableInvokeDynamic, "EnableInvokeDynamic was not set.");
  2517     intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
  2518     sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash);
  2519     hash_len = (int)strlen(hash_buf);
  2522   // Get the internal name as a c string
  2523   const char* src = (const char*) (name()->as_C_string());
  2524   const int src_length = (int)strlen(src);
  2526   char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
  2528   // Add L as type indicator
  2529   int dest_index = 0;
  2530   dest[dest_index++] = 'L';
  2532   // Add the actual class name
  2533   for (int src_index = 0; src_index < src_length; ) {
  2534     dest[dest_index++] = src[src_index++];
  2537   // If we have a hash, append it
  2538   for (int hash_index = 0; hash_index < hash_len; ) {
  2539     dest[dest_index++] = hash_buf[hash_index++];
  2542   // Add the semicolon and the NULL
  2543   dest[dest_index++] = ';';
  2544   dest[dest_index] = '\0';
  2545   return dest;
  2548 // different verisons of is_same_class_package
  2549 bool InstanceKlass::is_same_class_package(Klass* class2) {
  2550   Klass* class1 = this;
  2551   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
  2552   Symbol* classname1 = class1->name();
  2554   if (class2->oop_is_objArray()) {
  2555     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
  2557   oop classloader2;
  2558   if (class2->oop_is_instance()) {
  2559     classloader2 = InstanceKlass::cast(class2)->class_loader();
  2560   } else {
  2561     assert(class2->oop_is_typeArray(), "should be type array");
  2562     classloader2 = NULL;
  2564   Symbol* classname2 = class2->name();
  2566   return InstanceKlass::is_same_class_package(classloader1, classname1,
  2567                                               classloader2, classname2);
  2570 bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
  2571   Klass* class1 = this;
  2572   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
  2573   Symbol* classname1 = class1->name();
  2575   return InstanceKlass::is_same_class_package(classloader1, classname1,
  2576                                               classloader2, classname2);
  2579 // return true if two classes are in the same package, classloader
  2580 // and classname information is enough to determine a class's package
  2581 bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
  2582                                           oop class_loader2, Symbol* class_name2) {
  2583   if (class_loader1 != class_loader2) {
  2584     return false;
  2585   } else if (class_name1 == class_name2) {
  2586     return true;                // skip painful bytewise comparison
  2587   } else {
  2588     ResourceMark rm;
  2590     // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
  2591     // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
  2592     // Otherwise, we just compare jbyte values between the strings.
  2593     const jbyte *name1 = class_name1->base();
  2594     const jbyte *name2 = class_name2->base();
  2596     const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
  2597     const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
  2599     if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
  2600       // One of the two doesn't have a package.  Only return true
  2601       // if the other one also doesn't have a package.
  2602       return last_slash1 == last_slash2;
  2603     } else {
  2604       // Skip over '['s
  2605       if (*name1 == '[') {
  2606         do {
  2607           name1++;
  2608         } while (*name1 == '[');
  2609         if (*name1 != 'L') {
  2610           // Something is terribly wrong.  Shouldn't be here.
  2611           return false;
  2614       if (*name2 == '[') {
  2615         do {
  2616           name2++;
  2617         } while (*name2 == '[');
  2618         if (*name2 != 'L') {
  2619           // Something is terribly wrong.  Shouldn't be here.
  2620           return false;
  2624       // Check that package part is identical
  2625       int length1 = last_slash1 - name1;
  2626       int length2 = last_slash2 - name2;
  2628       return UTF8::equal(name1, length1, name2, length2);
  2633 // Returns true iff super_method can be overridden by a method in targetclassname
  2634 // See JSL 3rd edition 8.4.6.1
  2635 // Assumes name-signature match
  2636 // "this" is InstanceKlass of super_method which must exist
  2637 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
  2638 bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
  2639    // Private methods can not be overridden
  2640    if (super_method->is_private()) {
  2641      return false;
  2643    // If super method is accessible, then override
  2644    if ((super_method->is_protected()) ||
  2645        (super_method->is_public())) {
  2646      return true;
  2648    // Package-private methods are not inherited outside of package
  2649    assert(super_method->is_package_private(), "must be package private");
  2650    return(is_same_class_package(targetclassloader(), targetclassname));
  2653 /* defined for now in jvm.cpp, for historical reasons *--
  2654 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
  2655                                                      Symbol*& simple_name_result, TRAPS) {
  2656   ...
  2658 */
  2660 // tell if two classes have the same enclosing class (at package level)
  2661 bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
  2662                                                 Klass* class2_oop, TRAPS) {
  2663   if (class2_oop == class1())                       return true;
  2664   if (!class2_oop->oop_is_instance())  return false;
  2665   instanceKlassHandle class2(THREAD, class2_oop);
  2667   // must be in same package before we try anything else
  2668   if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
  2669     return false;
  2671   // As long as there is an outer1.getEnclosingClass,
  2672   // shift the search outward.
  2673   instanceKlassHandle outer1 = class1;
  2674   for (;;) {
  2675     // As we walk along, look for equalities between outer1 and class2.
  2676     // Eventually, the walks will terminate as outer1 stops
  2677     // at the top-level class around the original class.
  2678     bool ignore_inner_is_member;
  2679     Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
  2680                                                     CHECK_false);
  2681     if (next == NULL)  break;
  2682     if (next == class2())  return true;
  2683     outer1 = instanceKlassHandle(THREAD, next);
  2686   // Now do the same for class2.
  2687   instanceKlassHandle outer2 = class2;
  2688   for (;;) {
  2689     bool ignore_inner_is_member;
  2690     Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
  2691                                                     CHECK_false);
  2692     if (next == NULL)  break;
  2693     // Might as well check the new outer against all available values.
  2694     if (next == class1())  return true;
  2695     if (next == outer1())  return true;
  2696     outer2 = instanceKlassHandle(THREAD, next);
  2699   // If by this point we have not found an equality between the
  2700   // two classes, we know they are in separate package members.
  2701   return false;
  2705 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
  2706   jint access = access_flags().as_int();
  2708   // But check if it happens to be member class.
  2709   instanceKlassHandle ik(THREAD, this);
  2710   InnerClassesIterator iter(ik);
  2711   for (; !iter.done(); iter.next()) {
  2712     int ioff = iter.inner_class_info_index();
  2713     // Inner class attribute can be zero, skip it.
  2714     // Strange but true:  JVM spec. allows null inner class refs.
  2715     if (ioff == 0) continue;
  2717     // only look at classes that are already loaded
  2718     // since we are looking for the flags for our self.
  2719     Symbol* inner_name = ik->constants()->klass_name_at(ioff);
  2720     if ((ik->name() == inner_name)) {
  2721       // This is really a member class.
  2722       access = iter.inner_access_flags();
  2723       break;
  2726   // Remember to strip ACC_SUPER bit
  2727   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
  2730 jint InstanceKlass::jvmti_class_status() const {
  2731   jint result = 0;
  2733   if (is_linked()) {
  2734     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
  2737   if (is_initialized()) {
  2738     assert(is_linked(), "Class status is not consistent");
  2739     result |= JVMTI_CLASS_STATUS_INITIALIZED;
  2741   if (is_in_error_state()) {
  2742     result |= JVMTI_CLASS_STATUS_ERROR;
  2744   return result;
  2747 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
  2748   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
  2749   int method_table_offset_in_words = ioe->offset()/wordSize;
  2750   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
  2751                        / itableOffsetEntry::size();
  2753   for (int cnt = 0 ; ; cnt ++, ioe ++) {
  2754     // If the interface isn't implemented by the receiver class,
  2755     // the VM should throw IncompatibleClassChangeError.
  2756     if (cnt >= nof_interfaces) {
  2757       THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
  2760     Klass* ik = ioe->interface_klass();
  2761     if (ik == holder) break;
  2764   itableMethodEntry* ime = ioe->first_method_entry(this);
  2765   Method* m = ime[index].method();
  2766   if (m == NULL) {
  2767     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
  2769   return m;
  2773 #if INCLUDE_JVMTI
  2774 // update default_methods for redefineclasses for methods that are
  2775 // not yet in the vtable due to concurrent subclass define and superinterface
  2776 // redefinition
  2777 // Note: those in the vtable, should have been updated via adjust_method_entries
  2778 void InstanceKlass::adjust_default_methods(Method** old_methods, Method** new_methods,
  2779                                            int methods_length, bool* trace_name_printed) {
  2780   // search the default_methods for uses of either obsolete or EMCP methods
  2781   if (default_methods() != NULL) {
  2782     for (int j = 0; j < methods_length; j++) {
  2783       Method* old_method = old_methods[j];
  2784       Method* new_method = new_methods[j];
  2786       for (int index = 0; index < default_methods()->length(); index ++) {
  2787         if (default_methods()->at(index) == old_method) {
  2788           default_methods()->at_put(index, new_method);
  2789           if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
  2790             if (!(*trace_name_printed)) {
  2791               // RC_TRACE_MESG macro has an embedded ResourceMark
  2792               RC_TRACE_MESG(("adjust: klassname=%s default methods from name=%s",
  2793                              external_name(),
  2794                              old_method->method_holder()->external_name()));
  2795               *trace_name_printed = true;
  2797             RC_TRACE(0x00100000, ("default method update: %s(%s) ",
  2798                                   new_method->name()->as_C_string(),
  2799                                   new_method->signature()->as_C_string()));
  2806 #endif // INCLUDE_JVMTI
  2808 // On-stack replacement stuff
  2809 void InstanceKlass::add_osr_nmethod(nmethod* n) {
  2810   // only one compilation can be active
  2811   NEEDS_CLEANUP
  2812   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2813   OsrList_lock->lock_without_safepoint_check();
  2814   assert(n->is_osr_method(), "wrong kind of nmethod");
  2815   n->set_osr_link(osr_nmethods_head());
  2816   set_osr_nmethods_head(n);
  2817   // Raise the highest osr level if necessary
  2818   if (TieredCompilation) {
  2819     Method* m = n->method();
  2820     m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
  2822   // Remember to unlock again
  2823   OsrList_lock->unlock();
  2825   // Get rid of the osr methods for the same bci that have lower levels.
  2826   if (TieredCompilation) {
  2827     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
  2828       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
  2829       if (inv != NULL && inv->is_in_use()) {
  2830         inv->make_not_entrant();
  2837 void InstanceKlass::remove_osr_nmethod(nmethod* n) {
  2838   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2839   OsrList_lock->lock_without_safepoint_check();
  2840   assert(n->is_osr_method(), "wrong kind of nmethod");
  2841   nmethod* last = NULL;
  2842   nmethod* cur  = osr_nmethods_head();
  2843   int max_level = CompLevel_none;  // Find the max comp level excluding n
  2844   Method* m = n->method();
  2845   // Search for match
  2846   while(cur != NULL && cur != n) {
  2847     if (TieredCompilation && m == cur->method()) {
  2848       // Find max level before n
  2849       max_level = MAX2(max_level, cur->comp_level());
  2851     last = cur;
  2852     cur = cur->osr_link();
  2854   nmethod* next = NULL;
  2855   if (cur == n) {
  2856     next = cur->osr_link();
  2857     if (last == NULL) {
  2858       // Remove first element
  2859       set_osr_nmethods_head(next);
  2860     } else {
  2861       last->set_osr_link(next);
  2864   n->set_osr_link(NULL);
  2865   if (TieredCompilation) {
  2866     cur = next;
  2867     while (cur != NULL) {
  2868       // Find max level after n
  2869       if (m == cur->method()) {
  2870         max_level = MAX2(max_level, cur->comp_level());
  2872       cur = cur->osr_link();
  2874     m->set_highest_osr_comp_level(max_level);
  2876   // Remember to unlock again
  2877   OsrList_lock->unlock();
  2880 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
  2881   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2882   OsrList_lock->lock_without_safepoint_check();
  2883   nmethod* osr = osr_nmethods_head();
  2884   nmethod* best = NULL;
  2885   while (osr != NULL) {
  2886     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
  2887     // There can be a time when a c1 osr method exists but we are waiting
  2888     // for a c2 version. When c2 completes its osr nmethod we will trash
  2889     // the c1 version and only be able to find the c2 version. However
  2890     // while we overflow in the c1 code at back branches we don't want to
  2891     // try and switch to the same code as we are already running
  2893     if (osr->method() == m &&
  2894         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
  2895       if (match_level) {
  2896         if (osr->comp_level() == comp_level) {
  2897           // Found a match - return it.
  2898           OsrList_lock->unlock();
  2899           return osr;
  2901       } else {
  2902         if (best == NULL || (osr->comp_level() > best->comp_level())) {
  2903           if (osr->comp_level() == CompLevel_highest_tier) {
  2904             // Found the best possible - return it.
  2905             OsrList_lock->unlock();
  2906             return osr;
  2908           best = osr;
  2912     osr = osr->osr_link();
  2914   OsrList_lock->unlock();
  2915   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
  2916     return best;
  2918   return NULL;
  2921 void InstanceKlass::add_member_name(int index, Handle mem_name) {
  2922   jweak mem_name_wref = JNIHandles::make_weak_global(mem_name);
  2923   MutexLocker ml(MemberNameTable_lock);
  2924   assert(0 <= index && index < idnum_allocated_count(), "index is out of bounds");
  2925   DEBUG_ONLY(No_Safepoint_Verifier nsv);
  2927   if (_member_names == NULL) {
  2928     _member_names = new (ResourceObj::C_HEAP, mtClass) MemberNameTable(idnum_allocated_count());
  2930   _member_names->add_member_name(index, mem_name_wref);
  2933 oop InstanceKlass::get_member_name(int index) {
  2934   MutexLocker ml(MemberNameTable_lock);
  2935   assert(0 <= index && index < idnum_allocated_count(), "index is out of bounds");
  2936   DEBUG_ONLY(No_Safepoint_Verifier nsv);
  2938   if (_member_names == NULL) {
  2939     return NULL;
  2941   oop mem_name =_member_names->get_member_name(index);
  2942   return mem_name;
  2945 // -----------------------------------------------------------------------------------------------------
  2946 // Printing
  2948 #ifndef PRODUCT
  2950 #define BULLET  " - "
  2952 static const char* state_names[] = {
  2953   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
  2954 };
  2956 static void print_vtable(intptr_t* start, int len, outputStream* st) {
  2957   for (int i = 0; i < len; i++) {
  2958     intptr_t e = start[i];
  2959     st->print("%d : " INTPTR_FORMAT, i, e);
  2960     if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
  2961       st->print(" ");
  2962       ((Metadata*)e)->print_value_on(st);
  2964     st->cr();
  2968 void InstanceKlass::print_on(outputStream* st) const {
  2969   assert(is_klass(), "must be klass");
  2970   Klass::print_on(st);
  2972   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
  2973   st->print(BULLET"klass size:        %d", size());                               st->cr();
  2974   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
  2975   st->print(BULLET"state:             "); st->print_cr("%s", state_names[_init_state]);
  2976   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
  2977   st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
  2978   st->print(BULLET"sub:               ");
  2979   Klass* sub = subklass();
  2980   int n;
  2981   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
  2982     if (n < MaxSubklassPrintSize) {
  2983       sub->print_value_on(st);
  2984       st->print("   ");
  2987   if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
  2988   st->cr();
  2990   if (is_interface()) {
  2991     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
  2992     if (nof_implementors() == 1) {
  2993       st->print_cr(BULLET"implementor:    ");
  2994       st->print("   ");
  2995       implementor()->print_value_on(st);
  2996       st->cr();
  3000   st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
  3001   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
  3002   if (Verbose || WizardMode) {
  3003     Array<Method*>* method_array = methods();
  3004     for (int i = 0; i < method_array->length(); i++) {
  3005       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
  3008   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
  3009   st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);      st->cr();
  3010   if (Verbose && default_methods() != NULL) {
  3011     Array<Method*>* method_array = default_methods();
  3012     for (int i = 0; i < method_array->length(); i++) {
  3013       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
  3016   if (default_vtable_indices() != NULL) {
  3017     st->print(BULLET"default vtable indices:   "); default_vtable_indices()->print_value_on(st);       st->cr();
  3019   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
  3020   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
  3021   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
  3022   if (class_loader_data() != NULL) {
  3023     st->print(BULLET"class loader data:  ");
  3024     class_loader_data()->print_value_on(st);
  3025     st->cr();
  3027   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
  3028   if (source_file_name() != NULL) {
  3029     st->print(BULLET"source file:       ");
  3030     source_file_name()->print_value_on(st);
  3031     st->cr();
  3033   if (source_debug_extension() != NULL) {
  3034     st->print(BULLET"source debug extension:       ");
  3035     st->print("%s", source_debug_extension());
  3036     st->cr();
  3038   st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
  3039   st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
  3040   st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
  3041   st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
  3043     bool have_pv = false;
  3044     PreviousVersionWalker pvw(Thread::current(), (InstanceKlass*)this);
  3045     for (PreviousVersionNode * pv_node = pvw.next_previous_version();
  3046          pv_node != NULL; pv_node = pvw.next_previous_version()) {
  3047       if (!have_pv)
  3048         st->print(BULLET"previous version:  ");
  3049       have_pv = true;
  3050       pv_node->prev_constant_pool()->print_value_on(st);
  3052     if (have_pv) st->cr();
  3053   } // pvw is cleaned up
  3055   if (generic_signature() != NULL) {
  3056     st->print(BULLET"generic signature: ");
  3057     generic_signature()->print_value_on(st);
  3058     st->cr();
  3060   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
  3061   st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
  3062   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable());  st->cr();
  3063   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
  3064   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
  3065   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
  3066   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
  3067   FieldPrinter print_static_field(st);
  3068   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
  3069   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
  3070   FieldPrinter print_nonstatic_field(st);
  3071   ((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);
  3073   st->print(BULLET"non-static oop maps: ");
  3074   OopMapBlock* map     = start_of_nonstatic_oop_maps();
  3075   OopMapBlock* end_map = map + nonstatic_oop_map_count();
  3076   while (map < end_map) {
  3077     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
  3078     map++;
  3080   st->cr();
  3083 #endif //PRODUCT
  3085 void InstanceKlass::print_value_on(outputStream* st) const {
  3086   assert(is_klass(), "must be klass");
  3087   if (Verbose || WizardMode)  access_flags().print_on(st);
  3088   name()->print_value_on(st);
  3091 #ifndef PRODUCT
  3093 void FieldPrinter::do_field(fieldDescriptor* fd) {
  3094   _st->print(BULLET);
  3095    if (_obj == NULL) {
  3096      fd->print_on(_st);
  3097      _st->cr();
  3098    } else {
  3099      fd->print_on_for(_st, _obj);
  3100      _st->cr();
  3105 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
  3106   Klass::oop_print_on(obj, st);
  3108   if (this == SystemDictionary::String_klass()) {
  3109     typeArrayOop value  = java_lang_String::value(obj);
  3110     juint        offset = java_lang_String::offset(obj);
  3111     juint        length = java_lang_String::length(obj);
  3112     if (value != NULL &&
  3113         value->is_typeArray() &&
  3114         offset          <= (juint) value->length() &&
  3115         offset + length <= (juint) value->length()) {
  3116       st->print(BULLET"string: ");
  3117       java_lang_String::print(obj, st);
  3118       st->cr();
  3119       if (!WizardMode)  return;  // that is enough
  3123   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
  3124   FieldPrinter print_field(st, obj);
  3125   do_nonstatic_fields(&print_field);
  3127   if (this == SystemDictionary::Class_klass()) {
  3128     st->print(BULLET"signature: ");
  3129     java_lang_Class::print_signature(obj, st);
  3130     st->cr();
  3131     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
  3132     st->print(BULLET"fake entry for mirror: ");
  3133     mirrored_klass->print_value_on_maybe_null(st);
  3134     st->cr();
  3135     Klass* array_klass = java_lang_Class::array_klass(obj);
  3136     st->print(BULLET"fake entry for array: ");
  3137     array_klass->print_value_on_maybe_null(st);
  3138     st->cr();
  3139     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
  3140     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
  3141     Klass* real_klass = java_lang_Class::as_Klass(obj);
  3142     if (real_klass != NULL && real_klass->oop_is_instance()) {
  3143       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
  3145   } else if (this == SystemDictionary::MethodType_klass()) {
  3146     st->print(BULLET"signature: ");
  3147     java_lang_invoke_MethodType::print_signature(obj, st);
  3148     st->cr();
  3152 #endif //PRODUCT
  3154 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
  3155   st->print("a ");
  3156   name()->print_value_on(st);
  3157   obj->print_address_on(st);
  3158   if (this == SystemDictionary::String_klass()
  3159       && java_lang_String::value(obj) != NULL) {
  3160     ResourceMark rm;
  3161     int len = java_lang_String::length(obj);
  3162     int plen = (len < 24 ? len : 12);
  3163     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
  3164     st->print(" = \"%s\"", str);
  3165     if (len > plen)
  3166       st->print("...[%d]", len);
  3167   } else if (this == SystemDictionary::Class_klass()) {
  3168     Klass* k = java_lang_Class::as_Klass(obj);
  3169     st->print(" = ");
  3170     if (k != NULL) {
  3171       k->print_value_on(st);
  3172     } else {
  3173       const char* tname = type2name(java_lang_Class::primitive_type(obj));
  3174       st->print("%s", tname ? tname : "type?");
  3176   } else if (this == SystemDictionary::MethodType_klass()) {
  3177     st->print(" = ");
  3178     java_lang_invoke_MethodType::print_signature(obj, st);
  3179   } else if (java_lang_boxing_object::is_instance(obj)) {
  3180     st->print(" = ");
  3181     java_lang_boxing_object::print(obj, st);
  3182   } else if (this == SystemDictionary::LambdaForm_klass()) {
  3183     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
  3184     if (vmentry != NULL) {
  3185       st->print(" => ");
  3186       vmentry->print_value_on(st);
  3188   } else if (this == SystemDictionary::MemberName_klass()) {
  3189     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
  3190     if (vmtarget != NULL) {
  3191       st->print(" = ");
  3192       vmtarget->print_value_on(st);
  3193     } else {
  3194       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
  3195       st->print(".");
  3196       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
  3201 const char* InstanceKlass::internal_name() const {
  3202   return external_name();
  3205 #if INCLUDE_SERVICES
  3206 // Size Statistics
  3207 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
  3208   Klass::collect_statistics(sz);
  3210   sz->_inst_size  = HeapWordSize * size_helper();
  3211   sz->_vtab_bytes = HeapWordSize * align_object_offset(vtable_length());
  3212   sz->_itab_bytes = HeapWordSize * align_object_offset(itable_length());
  3213   sz->_nonstatic_oopmap_bytes = HeapWordSize *
  3214         ((is_interface() || is_anonymous()) ?
  3215          align_object_offset(nonstatic_oop_map_size()) :
  3216          nonstatic_oop_map_size());
  3218   int n = 0;
  3219   n += (sz->_methods_array_bytes         = sz->count_array(methods()));
  3220   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
  3221   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
  3222   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
  3223   n += (sz->_fields_bytes                = sz->count_array(fields()));
  3224   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
  3225   sz->_ro_bytes += n;
  3227   const ConstantPool* cp = constants();
  3228   if (cp) {
  3229     cp->collect_statistics(sz);
  3232   const Annotations* anno = annotations();
  3233   if (anno) {
  3234     anno->collect_statistics(sz);
  3237   const Array<Method*>* methods_array = methods();
  3238   if (methods()) {
  3239     for (int i = 0; i < methods_array->length(); i++) {
  3240       Method* method = methods_array->at(i);
  3241       if (method) {
  3242         sz->_method_count ++;
  3243         method->collect_statistics(sz);
  3248 #endif // INCLUDE_SERVICES
  3250 // Verification
  3252 class VerifyFieldClosure: public OopClosure {
  3253  protected:
  3254   template <class T> void do_oop_work(T* p) {
  3255     oop obj = oopDesc::load_decode_heap_oop(p);
  3256     if (!obj->is_oop_or_null()) {
  3257       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
  3258       Universe::print();
  3259       guarantee(false, "boom");
  3262  public:
  3263   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
  3264   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
  3265 };
  3267 void InstanceKlass::verify_on(outputStream* st) {
  3268 #ifndef PRODUCT
  3269   // Avoid redundant verifies, this really should be in product.
  3270   if (_verify_count == Universe::verify_count()) return;
  3271   _verify_count = Universe::verify_count();
  3272 #endif
  3274   // Verify Klass
  3275   Klass::verify_on(st);
  3277   // Verify that klass is present in ClassLoaderData
  3278   guarantee(class_loader_data()->contains_klass(this),
  3279             "this class isn't found in class loader data");
  3281   // Verify vtables
  3282   if (is_linked()) {
  3283     ResourceMark rm;
  3284     // $$$ This used to be done only for m/s collections.  Doing it
  3285     // always seemed a valid generalization.  (DLD -- 6/00)
  3286     vtable()->verify(st);
  3289   // Verify first subklass
  3290   if (subklass_oop() != NULL) {
  3291     guarantee(subklass_oop()->is_klass(), "should be klass");
  3294   // Verify siblings
  3295   Klass* super = this->super();
  3296   Klass* sib = next_sibling();
  3297   if (sib != NULL) {
  3298     if (sib == this) {
  3299       fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
  3302     guarantee(sib->is_klass(), "should be klass");
  3303     guarantee(sib->super() == super, "siblings should have same superklass");
  3306   // Verify implementor fields
  3307   Klass* im = implementor();
  3308   if (im != NULL) {
  3309     guarantee(is_interface(), "only interfaces should have implementor set");
  3310     guarantee(im->is_klass(), "should be klass");
  3311     guarantee(!im->is_interface() || im == this,
  3312       "implementors cannot be interfaces");
  3315   // Verify local interfaces
  3316   if (local_interfaces()) {
  3317     Array<Klass*>* local_interfaces = this->local_interfaces();
  3318     for (int j = 0; j < local_interfaces->length(); j++) {
  3319       Klass* e = local_interfaces->at(j);
  3320       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
  3324   // Verify transitive interfaces
  3325   if (transitive_interfaces() != NULL) {
  3326     Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
  3327     for (int j = 0; j < transitive_interfaces->length(); j++) {
  3328       Klass* e = transitive_interfaces->at(j);
  3329       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
  3333   // Verify methods
  3334   if (methods() != NULL) {
  3335     Array<Method*>* methods = this->methods();
  3336     for (int j = 0; j < methods->length(); j++) {
  3337       guarantee(methods->at(j)->is_method(), "non-method in methods array");
  3339     for (int j = 0; j < methods->length() - 1; j++) {
  3340       Method* m1 = methods->at(j);
  3341       Method* m2 = methods->at(j + 1);
  3342       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
  3346   // Verify method ordering
  3347   if (method_ordering() != NULL) {
  3348     Array<int>* method_ordering = this->method_ordering();
  3349     int length = method_ordering->length();
  3350     if (JvmtiExport::can_maintain_original_method_order() ||
  3351         ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
  3352       guarantee(length == methods()->length(), "invalid method ordering length");
  3353       jlong sum = 0;
  3354       for (int j = 0; j < length; j++) {
  3355         int original_index = method_ordering->at(j);
  3356         guarantee(original_index >= 0, "invalid method ordering index");
  3357         guarantee(original_index < length, "invalid method ordering index");
  3358         sum += original_index;
  3360       // Verify sum of indices 0,1,...,length-1
  3361       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
  3362     } else {
  3363       guarantee(length == 0, "invalid method ordering length");
  3367   // Verify default methods
  3368   if (default_methods() != NULL) {
  3369     Array<Method*>* methods = this->default_methods();
  3370     for (int j = 0; j < methods->length(); j++) {
  3371       guarantee(methods->at(j)->is_method(), "non-method in methods array");
  3373     for (int j = 0; j < methods->length() - 1; j++) {
  3374       Method* m1 = methods->at(j);
  3375       Method* m2 = methods->at(j + 1);
  3376       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
  3380   // Verify JNI static field identifiers
  3381   if (jni_ids() != NULL) {
  3382     jni_ids()->verify(this);
  3385   // Verify other fields
  3386   if (array_klasses() != NULL) {
  3387     guarantee(array_klasses()->is_klass(), "should be klass");
  3389   if (constants() != NULL) {
  3390     guarantee(constants()->is_constantPool(), "should be constant pool");
  3392   const Klass* host = host_klass();
  3393   if (host != NULL) {
  3394     guarantee(host->is_klass(), "should be klass");
  3398 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
  3399   Klass::oop_verify_on(obj, st);
  3400   VerifyFieldClosure blk;
  3401   obj->oop_iterate_no_header(&blk);
  3405 // JNIid class for jfieldIDs only
  3406 // Note to reviewers:
  3407 // These JNI functions are just moved over to column 1 and not changed
  3408 // in the compressed oops workspace.
  3409 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
  3410   _holder = holder;
  3411   _offset = offset;
  3412   _next = next;
  3413   debug_only(_is_static_field_id = false;)
  3417 JNIid* JNIid::find(int offset) {
  3418   JNIid* current = this;
  3419   while (current != NULL) {
  3420     if (current->offset() == offset) return current;
  3421     current = current->next();
  3423   return NULL;
  3426 void JNIid::deallocate(JNIid* current) {
  3427   while (current != NULL) {
  3428     JNIid* next = current->next();
  3429     delete current;
  3430     current = next;
  3435 void JNIid::verify(Klass* holder) {
  3436   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
  3437   int end_field_offset;
  3438   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
  3440   JNIid* current = this;
  3441   while (current != NULL) {
  3442     guarantee(current->holder() == holder, "Invalid klass in JNIid");
  3443 #ifdef ASSERT
  3444     int o = current->offset();
  3445     if (current->is_static_field_id()) {
  3446       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
  3448 #endif
  3449     current = current->next();
  3454 #ifdef ASSERT
  3455 void InstanceKlass::set_init_state(ClassState state) {
  3456   bool good_state = is_shared() ? (_init_state <= state)
  3457                                                : (_init_state < state);
  3458   assert(good_state || state == allocated, "illegal state transition");
  3459   _init_state = (u1)state;
  3461 #endif
  3464 // RedefineClasses() support for previous versions:
  3466 // Purge previous versions
  3467 static void purge_previous_versions_internal(InstanceKlass* ik, int emcp_method_count) {
  3468   if (ik->previous_versions() != NULL) {
  3469     // This klass has previous versions so see what we can cleanup
  3470     // while it is safe to do so.
  3472     int deleted_count = 0;    // leave debugging breadcrumbs
  3473     int live_count = 0;
  3474     ClassLoaderData* loader_data = ik->class_loader_data() == NULL ?
  3475                        ClassLoaderData::the_null_class_loader_data() :
  3476                        ik->class_loader_data();
  3478     // RC_TRACE macro has an embedded ResourceMark
  3479     RC_TRACE(0x00000200, ("purge: %s: previous version length=%d",
  3480       ik->external_name(), ik->previous_versions()->length()));
  3482     for (int i = ik->previous_versions()->length() - 1; i >= 0; i--) {
  3483       // check the previous versions array
  3484       PreviousVersionNode * pv_node = ik->previous_versions()->at(i);
  3485       ConstantPool* cp_ref = pv_node->prev_constant_pool();
  3486       assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
  3488       ConstantPool* pvcp = cp_ref;
  3489       if (!pvcp->on_stack()) {
  3490         // If the constant pool isn't on stack, none of the methods
  3491         // are executing.  Delete all the methods, the constant pool and
  3492         // and this previous version node.
  3493         GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3494         if (method_refs != NULL) {
  3495           for (int j = method_refs->length() - 1; j >= 0; j--) {
  3496             Method* method = method_refs->at(j);
  3497             assert(method != NULL, "method ref was unexpectedly cleared");
  3498             method_refs->remove_at(j);
  3499             // method will be freed with associated class.
  3502         // Remove the constant pool
  3503         delete pv_node;
  3504         // Since we are traversing the array backwards, we don't have to
  3505         // do anything special with the index.
  3506         ik->previous_versions()->remove_at(i);
  3507         deleted_count++;
  3508         continue;
  3509       } else {
  3510         RC_TRACE(0x00000200, ("purge: previous version @%d is alive", i));
  3511         assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
  3512         guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
  3513         live_count++;
  3516       // At least one method is live in this previous version, clean out
  3517       // the others or mark them as obsolete.
  3518       GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3519       if (method_refs != NULL) {
  3520         RC_TRACE(0x00000200, ("purge: previous methods length=%d",
  3521           method_refs->length()));
  3522         for (int j = method_refs->length() - 1; j >= 0; j--) {
  3523           Method* method = method_refs->at(j);
  3524           assert(method != NULL, "method ref was unexpectedly cleared");
  3526           // Remove the emcp method if it's not executing
  3527           // If it's been made obsolete by a redefinition of a non-emcp
  3528           // method, mark it as obsolete but leave it to clean up later.
  3529           if (!method->on_stack()) {
  3530             method_refs->remove_at(j);
  3531           } else if (emcp_method_count == 0) {
  3532             method->set_is_obsolete();
  3533           } else {
  3534             // RC_TRACE macro has an embedded ResourceMark
  3535             RC_TRACE(0x00000200,
  3536               ("purge: %s(%s): prev method @%d in version @%d is alive",
  3537               method->name()->as_C_string(),
  3538               method->signature()->as_C_string(), j, i));
  3543     assert(ik->previous_versions()->length() == live_count, "sanity check");
  3544     RC_TRACE(0x00000200,
  3545       ("purge: previous version stats: live=%d, deleted=%d", live_count,
  3546       deleted_count));
  3550 // External interface for use during class unloading.
  3551 void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
  3552   // Call with >0 emcp methods since they are not currently being redefined.
  3553   purge_previous_versions_internal(ik, 1);
  3557 // Potentially add an information node that contains pointers to the
  3558 // interesting parts of the previous version of the_class.
  3559 // This is also where we clean out any unused references.
  3560 // Note that while we delete nodes from the _previous_versions
  3561 // array, we never delete the array itself until the klass is
  3562 // unloaded. The has_been_redefined() query depends on that fact.
  3563 //
  3564 void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
  3565        BitMap* emcp_methods, int emcp_method_count) {
  3566   assert(Thread::current()->is_VM_thread(),
  3567          "only VMThread can add previous versions");
  3569   if (_previous_versions == NULL) {
  3570     // This is the first previous version so make some space.
  3571     // Start with 2 elements under the assumption that the class
  3572     // won't be redefined much.
  3573     _previous_versions =  new (ResourceObj::C_HEAP, mtClass)
  3574                             GrowableArray<PreviousVersionNode *>(2, true);
  3577   ConstantPool* cp_ref = ikh->constants();
  3579   // RC_TRACE macro has an embedded ResourceMark
  3580   RC_TRACE(0x00000400, ("adding previous version ref for %s @%d, EMCP_cnt=%d "
  3581                         "on_stack=%d",
  3582     ikh->external_name(), _previous_versions->length(), emcp_method_count,
  3583     cp_ref->on_stack()));
  3585   // If the constant pool for this previous version of the class
  3586   // is not marked as being on the stack, then none of the methods
  3587   // in this previous version of the class are on the stack so
  3588   // we don't need to create a new PreviousVersionNode. However,
  3589   // we still need to examine older previous versions below.
  3590   Array<Method*>* old_methods = ikh->methods();
  3592   if (cp_ref->on_stack()) {
  3593     PreviousVersionNode * pv_node = NULL;
  3594     if (emcp_method_count == 0) {
  3595       // non-shared ConstantPool gets a reference
  3596       pv_node = new PreviousVersionNode(cp_ref, NULL);
  3597       RC_TRACE(0x00000400,
  3598           ("add: all methods are obsolete; flushing any EMCP refs"));
  3599     } else {
  3600       int local_count = 0;
  3601       GrowableArray<Method*>* method_refs = new (ResourceObj::C_HEAP, mtClass)
  3602           GrowableArray<Method*>(emcp_method_count, true);
  3603       for (int i = 0; i < old_methods->length(); i++) {
  3604         if (emcp_methods->at(i)) {
  3605             // this old method is EMCP. Save it only if it's on the stack
  3606             Method* old_method = old_methods->at(i);
  3607             if (old_method->on_stack()) {
  3608               method_refs->append(old_method);
  3610           if (++local_count >= emcp_method_count) {
  3611             // no more EMCP methods so bail out now
  3612             break;
  3616       // non-shared ConstantPool gets a reference
  3617       pv_node = new PreviousVersionNode(cp_ref, method_refs);
  3619     // append new previous version.
  3620     _previous_versions->append(pv_node);
  3623   // Since the caller is the VMThread and we are at a safepoint, this
  3624   // is a good time to clear out unused references.
  3626   RC_TRACE(0x00000400, ("add: previous version length=%d",
  3627     _previous_versions->length()));
  3629   // Purge previous versions not executing on the stack
  3630   purge_previous_versions_internal(this, emcp_method_count);
  3632   int obsolete_method_count = old_methods->length() - emcp_method_count;
  3634   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
  3635       _previous_versions->length() > 0) {
  3636     // We have a mix of obsolete and EMCP methods so we have to
  3637     // clear out any matching EMCP method entries the hard way.
  3638     int local_count = 0;
  3639     for (int i = 0; i < old_methods->length(); i++) {
  3640       if (!emcp_methods->at(i)) {
  3641         // only obsolete methods are interesting
  3642         Method* old_method = old_methods->at(i);
  3643         Symbol* m_name = old_method->name();
  3644         Symbol* m_signature = old_method->signature();
  3646         // we might not have added the last entry
  3647         for (int j = _previous_versions->length() - 1; j >= 0; j--) {
  3648           // check the previous versions array for non executing obsolete methods
  3649           PreviousVersionNode * pv_node = _previous_versions->at(j);
  3651           GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3652           if (method_refs == NULL) {
  3653             // We have run into a PreviousVersion generation where
  3654             // all methods were made obsolete during that generation's
  3655             // RedefineClasses() operation. At the time of that
  3656             // operation, all EMCP methods were flushed so we don't
  3657             // have to go back any further.
  3658             //
  3659             // A NULL method_refs is different than an empty method_refs.
  3660             // We cannot infer any optimizations about older generations
  3661             // from an empty method_refs for the current generation.
  3662             break;
  3665           for (int k = method_refs->length() - 1; k >= 0; k--) {
  3666             Method* method = method_refs->at(k);
  3668             if (!method->is_obsolete() &&
  3669                 method->name() == m_name &&
  3670                 method->signature() == m_signature) {
  3671               // The current RedefineClasses() call has made all EMCP
  3672               // versions of this method obsolete so mark it as obsolete
  3673               // and remove the reference.
  3674               RC_TRACE(0x00000400,
  3675                 ("add: %s(%s): flush obsolete method @%d in version @%d",
  3676                 m_name->as_C_string(), m_signature->as_C_string(), k, j));
  3678               method->set_is_obsolete();
  3679               // Leave obsolete methods on the previous version list to
  3680               // clean up later.
  3681               break;
  3685           // The previous loop may not find a matching EMCP method, but
  3686           // that doesn't mean that we can optimize and not go any
  3687           // further back in the PreviousVersion generations. The EMCP
  3688           // method for this generation could have already been deleted,
  3689           // but there still may be an older EMCP method that has not
  3690           // been deleted.
  3693         if (++local_count >= obsolete_method_count) {
  3694           // no more obsolete methods so bail out now
  3695           break;
  3700 } // end add_previous_version()
  3703 // Determine if InstanceKlass has a previous version.
  3704 bool InstanceKlass::has_previous_version() const {
  3705   return (_previous_versions != NULL && _previous_versions->length() > 0);
  3706 } // end has_previous_version()
  3709 Method* InstanceKlass::method_with_idnum(int idnum) {
  3710   Method* m = NULL;
  3711   if (idnum < methods()->length()) {
  3712     m = methods()->at(idnum);
  3714   if (m == NULL || m->method_idnum() != idnum) {
  3715     for (int index = 0; index < methods()->length(); ++index) {
  3716       m = methods()->at(index);
  3717       if (m->method_idnum() == idnum) {
  3718         return m;
  3721     // None found, return null for the caller to handle.
  3722     return NULL;
  3724   return m;
  3727 jint InstanceKlass::get_cached_class_file_len() {
  3728   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
  3731 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
  3732   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
  3736 // Construct a PreviousVersionNode entry for the array hung off
  3737 // the InstanceKlass.
  3738 PreviousVersionNode::PreviousVersionNode(ConstantPool* prev_constant_pool,
  3739   GrowableArray<Method*>* prev_EMCP_methods) {
  3741   _prev_constant_pool = prev_constant_pool;
  3742   _prev_EMCP_methods = prev_EMCP_methods;
  3746 // Destroy a PreviousVersionNode
  3747 PreviousVersionNode::~PreviousVersionNode() {
  3748   if (_prev_constant_pool != NULL) {
  3749     _prev_constant_pool = NULL;
  3752   if (_prev_EMCP_methods != NULL) {
  3753     delete _prev_EMCP_methods;
  3757 // Construct a helper for walking the previous versions array
  3758 PreviousVersionWalker::PreviousVersionWalker(Thread* thread, InstanceKlass *ik) {
  3759   _thread = thread;
  3760   _previous_versions = ik->previous_versions();
  3761   _current_index = 0;
  3762   _current_p = NULL;
  3763   _current_constant_pool_handle = constantPoolHandle(thread, ik->constants());
  3767 // Return the interesting information for the next previous version
  3768 // of the klass. Returns NULL if there are no more previous versions.
  3769 PreviousVersionNode* PreviousVersionWalker::next_previous_version() {
  3770   if (_previous_versions == NULL) {
  3771     // no previous versions so nothing to return
  3772     return NULL;
  3775   _current_p = NULL;  // reset to NULL
  3776   _current_constant_pool_handle = NULL;
  3778   int length = _previous_versions->length();
  3780   while (_current_index < length) {
  3781     PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
  3783     // Save a handle to the constant pool for this previous version,
  3784     // which keeps all the methods from being deallocated.
  3785     _current_constant_pool_handle = constantPoolHandle(_thread, pv_node->prev_constant_pool());
  3786     _current_p = pv_node;
  3787     return pv_node;
  3790   return NULL;
  3791 } // end next_previous_version()

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