src/share/vm/oops/instanceKlass.cpp

Tue, 15 Apr 2014 17:02:20 -0400

author
coleenp
date
Tue, 15 Apr 2014 17:02:20 -0400
changeset 6626
9428a0b94204
parent 6518
62c54fcc0a35
child 6632
386dd1c71858
permissions
-rw-r--r--

8028497: SIGSEGV at ClassLoaderData::oops_do(OopClosure*, KlassClosure*, bool)
Summary: Keep class in CLD::_klasses list and mirror created for CDS classes if OOM during restore_shareable_info(). This keeps pointers consistent for CMS.
Reviewed-by: ehelin, stefank, jmasa, iklam

     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/metadataFactory.hpp"
    39 #include "memory/oopFactory.hpp"
    40 #include "oops/fieldStreams.hpp"
    41 #include "oops/instanceClassLoaderKlass.hpp"
    42 #include "oops/instanceKlass.hpp"
    43 #include "oops/instanceMirrorKlass.hpp"
    44 #include "oops/instanceOop.hpp"
    45 #include "oops/klass.inline.hpp"
    46 #include "oops/method.hpp"
    47 #include "oops/oop.inline.hpp"
    48 #include "oops/symbol.hpp"
    49 #include "prims/jvmtiExport.hpp"
    50 #include "prims/jvmtiRedefineClassesTrace.hpp"
    51 #include "prims/jvmtiRedefineClasses.hpp"
    52 #include "prims/methodComparator.hpp"
    53 #include "runtime/fieldDescriptor.hpp"
    54 #include "runtime/handles.inline.hpp"
    55 #include "runtime/javaCalls.hpp"
    56 #include "runtime/mutexLocker.hpp"
    57 #include "runtime/thread.inline.hpp"
    58 #include "services/classLoadingService.hpp"
    59 #include "services/threadService.hpp"
    60 #include "utilities/dtrace.hpp"
    61 #include "utilities/macros.hpp"
    62 #if INCLUDE_ALL_GCS
    63 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp"
    64 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
    65 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
    66 #include "gc_implementation/g1/g1RemSet.inline.hpp"
    67 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
    68 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
    69 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp"
    70 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
    71 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
    72 #include "oops/oop.pcgc.inline.hpp"
    73 #endif // INCLUDE_ALL_GCS
    74 #ifdef COMPILER1
    75 #include "c1/c1_Compiler.hpp"
    76 #endif
    78 #ifdef DTRACE_ENABLED
    80 #ifndef USDT2
    82 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
    83   char*, intptr_t, oop, intptr_t);
    84 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
    85   char*, intptr_t, oop, intptr_t, int);
    86 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
    87   char*, intptr_t, oop, intptr_t, int);
    88 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
    89   char*, intptr_t, oop, intptr_t, int);
    90 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
    91   char*, intptr_t, oop, intptr_t, int);
    92 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
    93   char*, intptr_t, oop, intptr_t, int);
    94 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
    95   char*, intptr_t, oop, intptr_t, int);
    96 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
    97   char*, intptr_t, oop, intptr_t, int);
    99 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
   100   {                                                              \
   101     char* data = NULL;                                           \
   102     int len = 0;                                                 \
   103     Symbol* name = (clss)->name();                               \
   104     if (name != NULL) {                                          \
   105       data = (char*)name->bytes();                               \
   106       len = name->utf8_length();                                 \
   107     }                                                            \
   108     HS_DTRACE_PROBE4(hotspot, class__initialization__##type,     \
   109       data, len, SOLARIS_ONLY((void *))(clss)->class_loader(), thread_type);           \
   110   }
   112 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
   113   {                                                              \
   114     char* data = NULL;                                           \
   115     int len = 0;                                                 \
   116     Symbol* name = (clss)->name();                               \
   117     if (name != NULL) {                                          \
   118       data = (char*)name->bytes();                               \
   119       len = name->utf8_length();                                 \
   120     }                                                            \
   121     HS_DTRACE_PROBE5(hotspot, class__initialization__##type,     \
   122       data, len, SOLARIS_ONLY((void *))(clss)->class_loader(), thread_type, wait);     \
   123   }
   124 #else /* USDT2 */
   126 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
   127 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
   128 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
   129 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
   130 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
   131 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
   132 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
   133 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
   134 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
   135   {                                                              \
   136     char* data = NULL;                                           \
   137     int len = 0;                                                 \
   138     Symbol* name = (clss)->name();                               \
   139     if (name != NULL) {                                          \
   140       data = (char*)name->bytes();                               \
   141       len = name->utf8_length();                                 \
   142     }                                                            \
   143     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
   144       data, len, (clss)->class_loader(), thread_type);           \
   145   }
   147 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
   148   {                                                              \
   149     char* data = NULL;                                           \
   150     int len = 0;                                                 \
   151     Symbol* name = (clss)->name();                               \
   152     if (name != NULL) {                                          \
   153       data = (char*)name->bytes();                               \
   154       len = name->utf8_length();                                 \
   155     }                                                            \
   156     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
   157       data, len, (clss)->class_loader(), thread_type, wait);     \
   158   }
   159 #endif /* USDT2 */
   161 #else //  ndef DTRACE_ENABLED
   163 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
   164 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
   166 #endif //  ndef DTRACE_ENABLED
   168 volatile int InstanceKlass::_total_instanceKlass_count = 0;
   170 InstanceKlass* InstanceKlass::allocate_instance_klass(
   171                                               ClassLoaderData* loader_data,
   172                                               int vtable_len,
   173                                               int itable_len,
   174                                               int static_field_size,
   175                                               int nonstatic_oop_map_size,
   176                                               ReferenceType rt,
   177                                               AccessFlags access_flags,
   178                                               Symbol* name,
   179                                               Klass* super_klass,
   180                                               bool is_anonymous,
   181                                               TRAPS) {
   183   int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
   184                                  access_flags.is_interface(), is_anonymous);
   186   // Allocation
   187   InstanceKlass* ik;
   188   if (rt == REF_NONE) {
   189     if (name == vmSymbols::java_lang_Class()) {
   190       ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
   191         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   192         access_flags, is_anonymous);
   193     } else if (name == vmSymbols::java_lang_ClassLoader() ||
   194           (SystemDictionary::ClassLoader_klass_loaded() &&
   195           super_klass != NULL &&
   196           super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
   197       ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
   198         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   199         access_flags, is_anonymous);
   200     } else {
   201       // normal class
   202       ik = new (loader_data, size, THREAD) InstanceKlass(
   203         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   204         access_flags, is_anonymous);
   205     }
   206   } else {
   207     // reference klass
   208     ik = new (loader_data, size, THREAD) InstanceRefKlass(
   209         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   210         access_flags, is_anonymous);
   211   }
   213   // Check for pending exception before adding to the loader data and incrementing
   214   // class count.  Can get OOM here.
   215   if (HAS_PENDING_EXCEPTION) {
   216     return NULL;
   217   }
   219   // Add all classes to our internal class loader list here,
   220   // including classes in the bootstrap (NULL) class loader.
   221   loader_data->add_class(ik);
   223   Atomic::inc(&_total_instanceKlass_count);
   224   return ik;
   225 }
   228 // copy method ordering from resource area to Metaspace
   229 void InstanceKlass::copy_method_ordering(intArray* m, TRAPS) {
   230   if (m != NULL) {
   231     // allocate a new array and copy contents (memcpy?)
   232     _method_ordering = MetadataFactory::new_array<int>(class_loader_data(), m->length(), CHECK);
   233     for (int i = 0; i < m->length(); i++) {
   234       _method_ordering->at_put(i, m->at(i));
   235     }
   236   } else {
   237     _method_ordering = Universe::the_empty_int_array();
   238   }
   239 }
   241 // create a new array of vtable_indices for default methods
   242 Array<int>* InstanceKlass::create_new_default_vtable_indices(int len, TRAPS) {
   243   Array<int>* vtable_indices = MetadataFactory::new_array<int>(class_loader_data(), len, CHECK_NULL);
   244   assert(default_vtable_indices() == NULL, "only create once");
   245   set_default_vtable_indices(vtable_indices);
   246   return vtable_indices;
   247 }
   249 InstanceKlass::InstanceKlass(int vtable_len,
   250                              int itable_len,
   251                              int static_field_size,
   252                              int nonstatic_oop_map_size,
   253                              ReferenceType rt,
   254                              AccessFlags access_flags,
   255                              bool is_anonymous) {
   256   No_Safepoint_Verifier no_safepoint; // until k becomes parsable
   258   int iksize = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
   259                                    access_flags.is_interface(), is_anonymous);
   261   set_vtable_length(vtable_len);
   262   set_itable_length(itable_len);
   263   set_static_field_size(static_field_size);
   264   set_nonstatic_oop_map_size(nonstatic_oop_map_size);
   265   set_access_flags(access_flags);
   266   _misc_flags = 0;  // initialize to zero
   267   set_is_anonymous(is_anonymous);
   268   assert(size() == iksize, "wrong size for object");
   270   set_array_klasses(NULL);
   271   set_methods(NULL);
   272   set_method_ordering(NULL);
   273   set_default_methods(NULL);
   274   set_default_vtable_indices(NULL);
   275   set_local_interfaces(NULL);
   276   set_transitive_interfaces(NULL);
   277   init_implementor();
   278   set_fields(NULL, 0);
   279   set_constants(NULL);
   280   set_class_loader_data(NULL);
   281   set_source_file_name_index(0);
   282   set_source_debug_extension(NULL, 0);
   283   set_array_name(NULL);
   284   set_inner_classes(NULL);
   285   set_static_oop_field_count(0);
   286   set_nonstatic_field_size(0);
   287   set_is_marked_dependent(false);
   288   set_init_state(InstanceKlass::allocated);
   289   set_init_thread(NULL);
   290   set_reference_type(rt);
   291   set_oop_map_cache(NULL);
   292   set_jni_ids(NULL);
   293   set_osr_nmethods_head(NULL);
   294   set_breakpoints(NULL);
   295   init_previous_versions();
   296   set_generic_signature_index(0);
   297   release_set_methods_jmethod_ids(NULL);
   298   set_annotations(NULL);
   299   set_jvmti_cached_class_field_map(NULL);
   300   set_initial_method_idnum(0);
   301   _dependencies = NULL;
   302   set_jvmti_cached_class_field_map(NULL);
   303   set_cached_class_file(NULL);
   304   set_initial_method_idnum(0);
   305   set_minor_version(0);
   306   set_major_version(0);
   307   NOT_PRODUCT(_verify_count = 0;)
   309   // initialize the non-header words to zero
   310   intptr_t* p = (intptr_t*)this;
   311   for (int index = InstanceKlass::header_size(); index < iksize; index++) {
   312     p[index] = NULL_WORD;
   313   }
   315   // Set temporary value until parseClassFile updates it with the real instance
   316   // size.
   317   set_layout_helper(Klass::instance_layout_helper(0, true));
   318 }
   321 void InstanceKlass::deallocate_methods(ClassLoaderData* loader_data,
   322                                        Array<Method*>* methods) {
   323   if (methods != NULL && methods != Universe::the_empty_method_array() &&
   324       !methods->is_shared()) {
   325     for (int i = 0; i < methods->length(); i++) {
   326       Method* method = methods->at(i);
   327       if (method == NULL) continue;  // maybe null if error processing
   328       // Only want to delete methods that are not executing for RedefineClasses.
   329       // The previous version will point to them so they're not totally dangling
   330       assert (!method->on_stack(), "shouldn't be called with methods on stack");
   331       MetadataFactory::free_metadata(loader_data, method);
   332     }
   333     MetadataFactory::free_array<Method*>(loader_data, methods);
   334   }
   335 }
   337 void InstanceKlass::deallocate_interfaces(ClassLoaderData* loader_data,
   338                                           Klass* super_klass,
   339                                           Array<Klass*>* local_interfaces,
   340                                           Array<Klass*>* transitive_interfaces) {
   341   // Only deallocate transitive interfaces if not empty, same as super class
   342   // or same as local interfaces.  See code in parseClassFile.
   343   Array<Klass*>* ti = transitive_interfaces;
   344   if (ti != Universe::the_empty_klass_array() && ti != local_interfaces) {
   345     // check that the interfaces don't come from super class
   346     Array<Klass*>* sti = (super_klass == NULL) ? NULL :
   347                     InstanceKlass::cast(super_klass)->transitive_interfaces();
   348     if (ti != sti && ti != NULL && !ti->is_shared()) {
   349       MetadataFactory::free_array<Klass*>(loader_data, ti);
   350     }
   351   }
   353   // local interfaces can be empty
   354   if (local_interfaces != Universe::the_empty_klass_array() &&
   355       local_interfaces != NULL && !local_interfaces->is_shared()) {
   356     MetadataFactory::free_array<Klass*>(loader_data, local_interfaces);
   357   }
   358 }
   360 // This function deallocates the metadata and C heap pointers that the
   361 // InstanceKlass points to.
   362 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
   364   // Orphan the mirror first, CMS thinks it's still live.
   365   if (java_mirror() != NULL) {
   366     java_lang_Class::set_klass(java_mirror(), NULL);
   367   }
   369   // Need to take this class off the class loader data list.
   370   loader_data->remove_class(this);
   372   // The array_klass for this class is created later, after error handling.
   373   // For class redefinition, we keep the original class so this scratch class
   374   // doesn't have an array class.  Either way, assert that there is nothing
   375   // to deallocate.
   376   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
   378   // Release C heap allocated data that this might point to, which includes
   379   // reference counting symbol names.
   380   release_C_heap_structures();
   382   deallocate_methods(loader_data, methods());
   383   set_methods(NULL);
   385   if (method_ordering() != NULL &&
   386       method_ordering() != Universe::the_empty_int_array() &&
   387       !method_ordering()->is_shared()) {
   388     MetadataFactory::free_array<int>(loader_data, method_ordering());
   389   }
   390   set_method_ordering(NULL);
   392   // default methods can be empty
   393   if (default_methods() != NULL &&
   394       default_methods() != Universe::the_empty_method_array() &&
   395       !default_methods()->is_shared()) {
   396     MetadataFactory::free_array<Method*>(loader_data, default_methods());
   397   }
   398   // Do NOT deallocate the default methods, they are owned by superinterfaces.
   399   set_default_methods(NULL);
   401   // default methods vtable indices can be empty
   402   if (default_vtable_indices() != NULL &&
   403       !default_vtable_indices()->is_shared()) {
   404     MetadataFactory::free_array<int>(loader_data, default_vtable_indices());
   405   }
   406   set_default_vtable_indices(NULL);
   409   // This array is in Klass, but remove it with the InstanceKlass since
   410   // this place would be the only caller and it can share memory with transitive
   411   // interfaces.
   412   if (secondary_supers() != NULL &&
   413       secondary_supers() != Universe::the_empty_klass_array() &&
   414       secondary_supers() != transitive_interfaces() &&
   415       !secondary_supers()->is_shared()) {
   416     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
   417   }
   418   set_secondary_supers(NULL);
   420   deallocate_interfaces(loader_data, super(), local_interfaces(), transitive_interfaces());
   421   set_transitive_interfaces(NULL);
   422   set_local_interfaces(NULL);
   424   if (fields() != NULL && !fields()->is_shared()) {
   425     MetadataFactory::free_array<jushort>(loader_data, fields());
   426   }
   427   set_fields(NULL, 0);
   429   // If a method from a redefined class is using this constant pool, don't
   430   // delete it, yet.  The new class's previous version will point to this.
   431   if (constants() != NULL) {
   432     assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
   433     if (!constants()->is_shared()) {
   434       MetadataFactory::free_metadata(loader_data, constants());
   435     }
   436     set_constants(NULL);
   437   }
   439   if (inner_classes() != NULL &&
   440       inner_classes() != Universe::the_empty_short_array() &&
   441       !inner_classes()->is_shared()) {
   442     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
   443   }
   444   set_inner_classes(NULL);
   446   // We should deallocate the Annotations instance if it's not in shared spaces.
   447   if (annotations() != NULL && !annotations()->is_shared()) {
   448     MetadataFactory::free_metadata(loader_data, annotations());
   449   }
   450   set_annotations(NULL);
   451 }
   453 bool InstanceKlass::should_be_initialized() const {
   454   return !is_initialized();
   455 }
   457 klassVtable* InstanceKlass::vtable() const {
   458   return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
   459 }
   461 klassItable* InstanceKlass::itable() const {
   462   return new klassItable(instanceKlassHandle(this));
   463 }
   465 void InstanceKlass::eager_initialize(Thread *thread) {
   466   if (!EagerInitialization) return;
   468   if (this->is_not_initialized()) {
   469     // abort if the the class has a class initializer
   470     if (this->class_initializer() != NULL) return;
   472     // abort if it is java.lang.Object (initialization is handled in genesis)
   473     Klass* super = this->super();
   474     if (super == NULL) return;
   476     // abort if the super class should be initialized
   477     if (!InstanceKlass::cast(super)->is_initialized()) return;
   479     // call body to expose the this pointer
   480     instanceKlassHandle this_oop(thread, this);
   481     eager_initialize_impl(this_oop);
   482   }
   483 }
   485 // JVMTI spec thinks there are signers and protection domain in the
   486 // instanceKlass.  These accessors pretend these fields are there.
   487 // The hprof specification also thinks these fields are in InstanceKlass.
   488 oop InstanceKlass::protection_domain() const {
   489   // return the protection_domain from the mirror
   490   return java_lang_Class::protection_domain(java_mirror());
   491 }
   493 // To remove these from requires an incompatible change and CCC request.
   494 objArrayOop InstanceKlass::signers() const {
   495   // return the signers from the mirror
   496   return java_lang_Class::signers(java_mirror());
   497 }
   499 oop InstanceKlass::init_lock() const {
   500   // return the init lock from the mirror
   501   oop lock = java_lang_Class::init_lock(java_mirror());
   502   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
   503          "only fully initialized state can have a null lock");
   504   return lock;
   505 }
   507 // Set the initialization lock to null so the object can be GC'ed.  Any racing
   508 // threads to get this lock will see a null lock and will not lock.
   509 // That's okay because they all check for initialized state after getting
   510 // the lock and return.
   511 void InstanceKlass::fence_and_clear_init_lock() {
   512   // make sure previous stores are all done, notably the init_state.
   513   OrderAccess::storestore();
   514   java_lang_Class::set_init_lock(java_mirror(), NULL);
   515   assert(!is_not_initialized(), "class must be initialized now");
   516 }
   518 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
   519   EXCEPTION_MARK;
   520   oop init_lock = this_oop->init_lock();
   521   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   523   // abort if someone beat us to the initialization
   524   if (!this_oop->is_not_initialized()) return;  // note: not equivalent to is_initialized()
   526   ClassState old_state = this_oop->init_state();
   527   link_class_impl(this_oop, true, THREAD);
   528   if (HAS_PENDING_EXCEPTION) {
   529     CLEAR_PENDING_EXCEPTION;
   530     // Abort if linking the class throws an exception.
   532     // Use a test to avoid redundantly resetting the state if there's
   533     // no change.  Set_init_state() asserts that state changes make
   534     // progress, whereas here we might just be spinning in place.
   535     if( old_state != this_oop->_init_state )
   536       this_oop->set_init_state (old_state);
   537   } else {
   538     // linking successfull, mark class as initialized
   539     this_oop->set_init_state (fully_initialized);
   540     this_oop->fence_and_clear_init_lock();
   541     // trace
   542     if (TraceClassInitialization) {
   543       ResourceMark rm(THREAD);
   544       tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
   545     }
   546   }
   547 }
   550 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
   551 // process. The step comments refers to the procedure described in that section.
   552 // Note: implementation moved to static method to expose the this pointer.
   553 void InstanceKlass::initialize(TRAPS) {
   554   if (this->should_be_initialized()) {
   555     HandleMark hm(THREAD);
   556     instanceKlassHandle this_oop(THREAD, this);
   557     initialize_impl(this_oop, CHECK);
   558     // Note: at this point the class may be initialized
   559     //       OR it may be in the state of being initialized
   560     //       in case of recursive initialization!
   561   } else {
   562     assert(is_initialized(), "sanity check");
   563   }
   564 }
   567 bool InstanceKlass::verify_code(
   568     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
   569   // 1) Verify the bytecodes
   570   Verifier::Mode mode =
   571     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
   572   return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
   573 }
   576 // Used exclusively by the shared spaces dump mechanism to prevent
   577 // classes mapped into the shared regions in new VMs from appearing linked.
   579 void InstanceKlass::unlink_class() {
   580   assert(is_linked(), "must be linked");
   581   _init_state = loaded;
   582 }
   584 void InstanceKlass::link_class(TRAPS) {
   585   assert(is_loaded(), "must be loaded");
   586   if (!is_linked()) {
   587     HandleMark hm(THREAD);
   588     instanceKlassHandle this_oop(THREAD, this);
   589     link_class_impl(this_oop, true, CHECK);
   590   }
   591 }
   593 // Called to verify that a class can link during initialization, without
   594 // throwing a VerifyError.
   595 bool InstanceKlass::link_class_or_fail(TRAPS) {
   596   assert(is_loaded(), "must be loaded");
   597   if (!is_linked()) {
   598     HandleMark hm(THREAD);
   599     instanceKlassHandle this_oop(THREAD, this);
   600     link_class_impl(this_oop, false, CHECK_false);
   601   }
   602   return is_linked();
   603 }
   605 bool InstanceKlass::link_class_impl(
   606     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
   607   // check for error state
   608   if (this_oop->is_in_error_state()) {
   609     ResourceMark rm(THREAD);
   610     THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
   611                this_oop->external_name(), false);
   612   }
   613   // return if already verified
   614   if (this_oop->is_linked()) {
   615     return true;
   616   }
   618   // Timing
   619   // timer handles recursion
   620   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
   621   JavaThread* jt = (JavaThread*)THREAD;
   623   // link super class before linking this class
   624   instanceKlassHandle super(THREAD, this_oop->super());
   625   if (super.not_null()) {
   626     if (super->is_interface()) {  // check if super class is an interface
   627       ResourceMark rm(THREAD);
   628       Exceptions::fthrow(
   629         THREAD_AND_LOCATION,
   630         vmSymbols::java_lang_IncompatibleClassChangeError(),
   631         "class %s has interface %s as super class",
   632         this_oop->external_name(),
   633         super->external_name()
   634       );
   635       return false;
   636     }
   638     link_class_impl(super, throw_verifyerror, CHECK_false);
   639   }
   641   // link all interfaces implemented by this class before linking this class
   642   Array<Klass*>* interfaces = this_oop->local_interfaces();
   643   int num_interfaces = interfaces->length();
   644   for (int index = 0; index < num_interfaces; index++) {
   645     HandleMark hm(THREAD);
   646     instanceKlassHandle ih(THREAD, interfaces->at(index));
   647     link_class_impl(ih, throw_verifyerror, CHECK_false);
   648   }
   650   // in case the class is linked in the process of linking its superclasses
   651   if (this_oop->is_linked()) {
   652     return true;
   653   }
   655   // trace only the link time for this klass that includes
   656   // the verification time
   657   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
   658                              ClassLoader::perf_class_link_selftime(),
   659                              ClassLoader::perf_classes_linked(),
   660                              jt->get_thread_stat()->perf_recursion_counts_addr(),
   661                              jt->get_thread_stat()->perf_timers_addr(),
   662                              PerfClassTraceTime::CLASS_LINK);
   664   // verification & rewriting
   665   {
   666     oop init_lock = this_oop->init_lock();
   667     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   668     // rewritten will have been set if loader constraint error found
   669     // on an earlier link attempt
   670     // don't verify or rewrite if already rewritten
   672     if (!this_oop->is_linked()) {
   673       if (!this_oop->is_rewritten()) {
   674         {
   675           // Timer includes any side effects of class verification (resolution,
   676           // etc), but not recursive entry into verify_code().
   677           PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
   678                                    ClassLoader::perf_class_verify_selftime(),
   679                                    ClassLoader::perf_classes_verified(),
   680                                    jt->get_thread_stat()->perf_recursion_counts_addr(),
   681                                    jt->get_thread_stat()->perf_timers_addr(),
   682                                    PerfClassTraceTime::CLASS_VERIFY);
   683           bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
   684           if (!verify_ok) {
   685             return false;
   686           }
   687         }
   689         // Just in case a side-effect of verify linked this class already
   690         // (which can sometimes happen since the verifier loads classes
   691         // using custom class loaders, which are free to initialize things)
   692         if (this_oop->is_linked()) {
   693           return true;
   694         }
   696         // also sets rewritten
   697         this_oop->rewrite_class(CHECK_false);
   698       }
   700       // relocate jsrs and link methods after they are all rewritten
   701       this_oop->link_methods(CHECK_false);
   703       // Initialize the vtable and interface table after
   704       // methods have been rewritten since rewrite may
   705       // fabricate new Method*s.
   706       // also does loader constraint checking
   707       if (!this_oop()->is_shared()) {
   708         ResourceMark rm(THREAD);
   709         this_oop->vtable()->initialize_vtable(true, CHECK_false);
   710         this_oop->itable()->initialize_itable(true, CHECK_false);
   711       }
   712 #ifdef ASSERT
   713       else {
   714         ResourceMark rm(THREAD);
   715         this_oop->vtable()->verify(tty, true);
   716         // In case itable verification is ever added.
   717         // this_oop->itable()->verify(tty, true);
   718       }
   719 #endif
   720       this_oop->set_init_state(linked);
   721       if (JvmtiExport::should_post_class_prepare()) {
   722         Thread *thread = THREAD;
   723         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
   724         JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
   725       }
   726     }
   727   }
   728   return true;
   729 }
   732 // Rewrite the byte codes of all of the methods of a class.
   733 // The rewriter must be called exactly once. Rewriting must happen after
   734 // verification but before the first method of the class is executed.
   735 void InstanceKlass::rewrite_class(TRAPS) {
   736   assert(is_loaded(), "must be loaded");
   737   instanceKlassHandle this_oop(THREAD, this);
   738   if (this_oop->is_rewritten()) {
   739     assert(this_oop()->is_shared(), "rewriting an unshared class?");
   740     return;
   741   }
   742   Rewriter::rewrite(this_oop, CHECK);
   743   this_oop->set_rewritten();
   744 }
   746 // Now relocate and link method entry points after class is rewritten.
   747 // This is outside is_rewritten flag. In case of an exception, it can be
   748 // executed more than once.
   749 void InstanceKlass::link_methods(TRAPS) {
   750   int len = methods()->length();
   751   for (int i = len-1; i >= 0; i--) {
   752     methodHandle m(THREAD, methods()->at(i));
   754     // Set up method entry points for compiler and interpreter    .
   755     m->link_method(m, CHECK);
   757     // This is for JVMTI and unrelated to relocator but the last thing we do
   758 #ifdef ASSERT
   759     if (StressMethodComparator) {
   760       ResourceMark rm(THREAD);
   761       static int nmc = 0;
   762       for (int j = i; j >= 0 && j >= i-4; j--) {
   763         if ((++nmc % 1000) == 0)  tty->print_cr("Have run MethodComparator %d times...", nmc);
   764         bool z = MethodComparator::methods_EMCP(m(),
   765                    methods()->at(j));
   766         if (j == i && !z) {
   767           tty->print("MethodComparator FAIL: "); m->print(); m->print_codes();
   768           assert(z, "method must compare equal to itself");
   769         }
   770       }
   771     }
   772 #endif //ASSERT
   773   }
   774 }
   777 void InstanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
   778   // Make sure klass is linked (verified) before initialization
   779   // A class could already be verified, since it has been reflected upon.
   780   this_oop->link_class(CHECK);
   782   DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_oop()), -1);
   784   bool wait = false;
   786   // refer to the JVM book page 47 for description of steps
   787   // Step 1
   788   {
   789     oop init_lock = this_oop->init_lock();
   790     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   792     Thread *self = THREAD; // it's passed the current thread
   794     // Step 2
   795     // If we were to use wait() instead of waitInterruptibly() then
   796     // we might end up throwing IE from link/symbol resolution sites
   797     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
   798     while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
   799         wait = true;
   800       ol.waitUninterruptibly(CHECK);
   801     }
   803     // Step 3
   804     if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
   805       DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_oop()), -1,wait);
   806       return;
   807     }
   809     // Step 4
   810     if (this_oop->is_initialized()) {
   811       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_oop()), -1,wait);
   812       return;
   813     }
   815     // Step 5
   816     if (this_oop->is_in_error_state()) {
   817       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_oop()), -1,wait);
   818       ResourceMark rm(THREAD);
   819       const char* desc = "Could not initialize class ";
   820       const char* className = this_oop->external_name();
   821       size_t msglen = strlen(desc) + strlen(className) + 1;
   822       char* message = NEW_RESOURCE_ARRAY(char, msglen);
   823       if (NULL == message) {
   824         // Out of memory: can't create detailed error message
   825         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
   826       } else {
   827         jio_snprintf(message, msglen, "%s%s", desc, className);
   828         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
   829       }
   830     }
   832     // Step 6
   833     this_oop->set_init_state(being_initialized);
   834     this_oop->set_init_thread(self);
   835   }
   837   // Step 7
   838   Klass* super_klass = this_oop->super();
   839   if (super_klass != NULL && !this_oop->is_interface() && super_klass->should_be_initialized()) {
   840     super_klass->initialize(THREAD);
   842     if (HAS_PENDING_EXCEPTION) {
   843       Handle e(THREAD, PENDING_EXCEPTION);
   844       CLEAR_PENDING_EXCEPTION;
   845       {
   846         EXCEPTION_MARK;
   847         this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
   848         CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, superclass initialization error is thrown below
   849       }
   850       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_oop()), -1,wait);
   851       THROW_OOP(e());
   852     }
   853   }
   855   if (this_oop->has_default_methods()) {
   856     // Step 7.5: initialize any interfaces which have default methods
   857     for (int i = 0; i < this_oop->local_interfaces()->length(); ++i) {
   858       Klass* iface = this_oop->local_interfaces()->at(i);
   859       InstanceKlass* ik = InstanceKlass::cast(iface);
   860       if (ik->has_default_methods() && ik->should_be_initialized()) {
   861         ik->initialize(THREAD);
   863         if (HAS_PENDING_EXCEPTION) {
   864           Handle e(THREAD, PENDING_EXCEPTION);
   865           CLEAR_PENDING_EXCEPTION;
   866           {
   867             EXCEPTION_MARK;
   868             // Locks object, set state, and notify all waiting threads
   869             this_oop->set_initialization_state_and_notify(
   870                 initialization_error, THREAD);
   872             // ignore any exception thrown, superclass initialization error is
   873             // thrown below
   874             CLEAR_PENDING_EXCEPTION;
   875           }
   876           DTRACE_CLASSINIT_PROBE_WAIT(
   877               super__failed, InstanceKlass::cast(this_oop()), -1, wait);
   878           THROW_OOP(e());
   879         }
   880       }
   881     }
   882   }
   884   // Step 8
   885   {
   886     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
   887     JavaThread* jt = (JavaThread*)THREAD;
   888     DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_oop()), -1,wait);
   889     // Timer includes any side effects of class initialization (resolution,
   890     // etc), but not recursive entry into call_class_initializer().
   891     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
   892                              ClassLoader::perf_class_init_selftime(),
   893                              ClassLoader::perf_classes_inited(),
   894                              jt->get_thread_stat()->perf_recursion_counts_addr(),
   895                              jt->get_thread_stat()->perf_timers_addr(),
   896                              PerfClassTraceTime::CLASS_CLINIT);
   897     this_oop->call_class_initializer(THREAD);
   898   }
   900   // Step 9
   901   if (!HAS_PENDING_EXCEPTION) {
   902     this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
   903     { ResourceMark rm(THREAD);
   904       debug_only(this_oop->vtable()->verify(tty, true);)
   905     }
   906   }
   907   else {
   908     // Step 10 and 11
   909     Handle e(THREAD, PENDING_EXCEPTION);
   910     CLEAR_PENDING_EXCEPTION;
   911     {
   912       EXCEPTION_MARK;
   913       this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
   914       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
   915     }
   916     DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_oop()), -1,wait);
   917     if (e->is_a(SystemDictionary::Error_klass())) {
   918       THROW_OOP(e());
   919     } else {
   920       JavaCallArguments args(e);
   921       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
   922                 vmSymbols::throwable_void_signature(),
   923                 &args);
   924     }
   925   }
   926   DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_oop()), -1,wait);
   927 }
   930 // Note: implementation moved to static method to expose the this pointer.
   931 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
   932   instanceKlassHandle kh(THREAD, this);
   933   set_initialization_state_and_notify_impl(kh, state, CHECK);
   934 }
   936 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
   937   oop init_lock = this_oop->init_lock();
   938   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   939   this_oop->set_init_state(state);
   940   this_oop->fence_and_clear_init_lock();
   941   ol.notify_all(CHECK);
   942 }
   944 // The embedded _implementor field can only record one implementor.
   945 // When there are more than one implementors, the _implementor field
   946 // is set to the interface Klass* itself. Following are the possible
   947 // values for the _implementor field:
   948 //   NULL                  - no implementor
   949 //   implementor Klass*    - one implementor
   950 //   self                  - more than one implementor
   951 //
   952 // The _implementor field only exists for interfaces.
   953 void InstanceKlass::add_implementor(Klass* k) {
   954   assert(Compile_lock->owned_by_self(), "");
   955   assert(is_interface(), "not interface");
   956   // Filter out my subinterfaces.
   957   // (Note: Interfaces are never on the subklass list.)
   958   if (InstanceKlass::cast(k)->is_interface()) return;
   960   // Filter out subclasses whose supers already implement me.
   961   // (Note: CHA must walk subclasses of direct implementors
   962   // in order to locate indirect implementors.)
   963   Klass* sk = InstanceKlass::cast(k)->super();
   964   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
   965     // We only need to check one immediate superclass, since the
   966     // implements_interface query looks at transitive_interfaces.
   967     // Any supers of the super have the same (or fewer) transitive_interfaces.
   968     return;
   970   Klass* ik = implementor();
   971   if (ik == NULL) {
   972     set_implementor(k);
   973   } else if (ik != this) {
   974     // There is already an implementor. Use itself as an indicator of
   975     // more than one implementors.
   976     set_implementor(this);
   977   }
   979   // The implementor also implements the transitive_interfaces
   980   for (int index = 0; index < local_interfaces()->length(); index++) {
   981     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
   982   }
   983 }
   985 void InstanceKlass::init_implementor() {
   986   if (is_interface()) {
   987     set_implementor(NULL);
   988   }
   989 }
   992 void InstanceKlass::process_interfaces(Thread *thread) {
   993   // link this class into the implementors list of every interface it implements
   994   Klass* this_as_klass_oop = this;
   995   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
   996     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
   997     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
   998     assert(interf->is_interface(), "expected interface");
   999     interf->add_implementor(this_as_klass_oop);
  1003 bool InstanceKlass::can_be_primary_super_slow() const {
  1004   if (is_interface())
  1005     return false;
  1006   else
  1007     return Klass::can_be_primary_super_slow();
  1010 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
  1011   // The secondaries are the implemented interfaces.
  1012   InstanceKlass* ik = InstanceKlass::cast(this);
  1013   Array<Klass*>* interfaces = ik->transitive_interfaces();
  1014   int num_secondaries = num_extra_slots + interfaces->length();
  1015   if (num_secondaries == 0) {
  1016     // Must share this for correct bootstrapping!
  1017     set_secondary_supers(Universe::the_empty_klass_array());
  1018     return NULL;
  1019   } else if (num_extra_slots == 0) {
  1020     // The secondary super list is exactly the same as the transitive interfaces.
  1021     // Redefine classes has to be careful not to delete this!
  1022     set_secondary_supers(interfaces);
  1023     return NULL;
  1024   } else {
  1025     // Copy transitive interfaces to a temporary growable array to be constructed
  1026     // into the secondary super list with extra slots.
  1027     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
  1028     for (int i = 0; i < interfaces->length(); i++) {
  1029       secondaries->push(interfaces->at(i));
  1031     return secondaries;
  1035 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
  1036   if (k->is_interface()) {
  1037     return implements_interface(k);
  1038   } else {
  1039     return Klass::compute_is_subtype_of(k);
  1043 bool InstanceKlass::implements_interface(Klass* k) const {
  1044   if (this == k) return true;
  1045   assert(k->is_interface(), "should be an interface class");
  1046   for (int i = 0; i < transitive_interfaces()->length(); i++) {
  1047     if (transitive_interfaces()->at(i) == k) {
  1048       return true;
  1051   return false;
  1054 bool InstanceKlass::is_same_or_direct_interface(Klass *k) const {
  1055   // Verify direct super interface
  1056   if (this == k) return true;
  1057   assert(k->is_interface(), "should be an interface class");
  1058   for (int i = 0; i < local_interfaces()->length(); i++) {
  1059     if (local_interfaces()->at(i) == k) {
  1060       return true;
  1063   return false;
  1066 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
  1067   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
  1068   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
  1069     report_java_out_of_memory("Requested array size exceeds VM limit");
  1070     JvmtiExport::post_array_size_exhausted();
  1071     THROW_OOP_0(Universe::out_of_memory_error_array_size());
  1073   int size = objArrayOopDesc::object_size(length);
  1074   Klass* ak = array_klass(n, CHECK_NULL);
  1075   KlassHandle h_ak (THREAD, ak);
  1076   objArrayOop o =
  1077     (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
  1078   return o;
  1081 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
  1082   if (TraceFinalizerRegistration) {
  1083     tty->print("Registered ");
  1084     i->print_value_on(tty);
  1085     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
  1087   instanceHandle h_i(THREAD, i);
  1088   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
  1089   JavaValue result(T_VOID);
  1090   JavaCallArguments args(h_i);
  1091   methodHandle mh (THREAD, Universe::finalizer_register_method());
  1092   JavaCalls::call(&result, mh, &args, CHECK_NULL);
  1093   return h_i();
  1096 instanceOop InstanceKlass::allocate_instance(TRAPS) {
  1097   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
  1098   int size = size_helper();  // Query before forming handle.
  1100   KlassHandle h_k(THREAD, this);
  1102   instanceOop i;
  1104   i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
  1105   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
  1106     i = register_finalizer(i, CHECK_NULL);
  1108   return i;
  1111 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
  1112   if (is_interface() || is_abstract()) {
  1113     ResourceMark rm(THREAD);
  1114     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
  1115               : vmSymbols::java_lang_InstantiationException(), external_name());
  1117   if (this == SystemDictionary::Class_klass()) {
  1118     ResourceMark rm(THREAD);
  1119     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
  1120               : vmSymbols::java_lang_IllegalAccessException(), external_name());
  1124 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
  1125   instanceKlassHandle this_oop(THREAD, this);
  1126   return array_klass_impl(this_oop, or_null, n, THREAD);
  1129 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
  1130   if (this_oop->array_klasses() == NULL) {
  1131     if (or_null) return NULL;
  1133     ResourceMark rm;
  1134     JavaThread *jt = (JavaThread *)THREAD;
  1136       // Atomic creation of array_klasses
  1137       MutexLocker mc(Compile_lock, THREAD);   // for vtables
  1138       MutexLocker ma(MultiArray_lock, THREAD);
  1140       // Check if update has already taken place
  1141       if (this_oop->array_klasses() == NULL) {
  1142         Klass*    k = ObjArrayKlass::allocate_objArray_klass(this_oop->class_loader_data(), 1, this_oop, CHECK_NULL);
  1143         this_oop->set_array_klasses(k);
  1147   // _this will always be set at this point
  1148   ObjArrayKlass* oak = (ObjArrayKlass*)this_oop->array_klasses();
  1149   if (or_null) {
  1150     return oak->array_klass_or_null(n);
  1152   return oak->array_klass(n, CHECK_NULL);
  1155 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
  1156   return array_klass_impl(or_null, 1, THREAD);
  1159 void InstanceKlass::call_class_initializer(TRAPS) {
  1160   instanceKlassHandle ik (THREAD, this);
  1161   call_class_initializer_impl(ik, THREAD);
  1164 static int call_class_initializer_impl_counter = 0;   // for debugging
  1166 Method* InstanceKlass::class_initializer() {
  1167   Method* clinit = find_method(
  1168       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
  1169   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
  1170     return clinit;
  1172   return NULL;
  1175 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
  1176   if (ReplayCompiles &&
  1177       (ReplaySuppressInitializers == 1 ||
  1178        ReplaySuppressInitializers >= 2 && this_oop->class_loader() != NULL)) {
  1179     // Hide the existence of the initializer for the purpose of replaying the compile
  1180     return;
  1183   methodHandle h_method(THREAD, this_oop->class_initializer());
  1184   assert(!this_oop->is_initialized(), "we cannot initialize twice");
  1185   if (TraceClassInitialization) {
  1186     tty->print("%d Initializing ", call_class_initializer_impl_counter++);
  1187     this_oop->name()->print_value();
  1188     tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
  1190   if (h_method() != NULL) {
  1191     JavaCallArguments args; // No arguments
  1192     JavaValue result(T_VOID);
  1193     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
  1198 void InstanceKlass::mask_for(methodHandle method, int bci,
  1199   InterpreterOopMap* entry_for) {
  1200   // Dirty read, then double-check under a lock.
  1201   if (_oop_map_cache == NULL) {
  1202     // Otherwise, allocate a new one.
  1203     MutexLocker x(OopMapCacheAlloc_lock);
  1204     // First time use. Allocate a cache in C heap
  1205     if (_oop_map_cache == NULL) {
  1206       // Release stores from OopMapCache constructor before assignment
  1207       // to _oop_map_cache. C++ compilers on ppc do not emit the
  1208       // required memory barrier only because of the volatile
  1209       // qualifier of _oop_map_cache.
  1210       OrderAccess::release_store_ptr(&_oop_map_cache, new OopMapCache());
  1213   // _oop_map_cache is constant after init; lookup below does is own locking.
  1214   _oop_map_cache->lookup(method, bci, entry_for);
  1218 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  1219   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
  1220     Symbol* f_name = fs.name();
  1221     Symbol* f_sig  = fs.signature();
  1222     if (f_name == name && f_sig == sig) {
  1223       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
  1224       return true;
  1227   return false;
  1231 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  1232   const int n = local_interfaces()->length();
  1233   for (int i = 0; i < n; i++) {
  1234     Klass* intf1 = local_interfaces()->at(i);
  1235     assert(intf1->is_interface(), "just checking type");
  1236     // search for field in current interface
  1237     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
  1238       assert(fd->is_static(), "interface field must be static");
  1239       return intf1;
  1241     // search for field in direct superinterfaces
  1242     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
  1243     if (intf2 != NULL) return intf2;
  1245   // otherwise field lookup fails
  1246   return NULL;
  1250 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  1251   // search order according to newest JVM spec (5.4.3.2, p.167).
  1252   // 1) search for field in current klass
  1253   if (find_local_field(name, sig, fd)) {
  1254     return const_cast<InstanceKlass*>(this);
  1256   // 2) search for field recursively in direct superinterfaces
  1257   { Klass* intf = find_interface_field(name, sig, fd);
  1258     if (intf != NULL) return intf;
  1260   // 3) apply field lookup recursively if superclass exists
  1261   { Klass* supr = super();
  1262     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
  1264   // 4) otherwise field lookup fails
  1265   return NULL;
  1269 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
  1270   // search order according to newest JVM spec (5.4.3.2, p.167).
  1271   // 1) search for field in current klass
  1272   if (find_local_field(name, sig, fd)) {
  1273     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
  1275   // 2) search for field recursively in direct superinterfaces
  1276   if (is_static) {
  1277     Klass* intf = find_interface_field(name, sig, fd);
  1278     if (intf != NULL) return intf;
  1280   // 3) apply field lookup recursively if superclass exists
  1281   { Klass* supr = super();
  1282     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
  1284   // 4) otherwise field lookup fails
  1285   return NULL;
  1289 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
  1290   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
  1291     if (fs.offset() == offset) {
  1292       fd->reinitialize(const_cast<InstanceKlass*>(this), fs.index());
  1293       if (fd->is_static() == is_static) return true;
  1296   return false;
  1300 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
  1301   Klass* klass = const_cast<InstanceKlass*>(this);
  1302   while (klass != NULL) {
  1303     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
  1304       return true;
  1306     klass = klass->super();
  1308   return false;
  1312 void InstanceKlass::methods_do(void f(Method* method)) {
  1313   int len = methods()->length();
  1314   for (int index = 0; index < len; index++) {
  1315     Method* m = methods()->at(index);
  1316     assert(m->is_method(), "must be method");
  1317     f(m);
  1322 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
  1323   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
  1324     if (fs.access_flags().is_static()) {
  1325       fieldDescriptor& fd = fs.field_descriptor();
  1326       cl->do_field(&fd);
  1332 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, Handle, TRAPS), Handle mirror, TRAPS) {
  1333   instanceKlassHandle h_this(THREAD, this);
  1334   do_local_static_fields_impl(h_this, f, mirror, CHECK);
  1338 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_k,
  1339                              void f(fieldDescriptor* fd, Handle mirror, TRAPS), Handle mirror, TRAPS) {
  1340   for (JavaFieldStream fs(this_k()); !fs.done(); fs.next()) {
  1341     if (fs.access_flags().is_static()) {
  1342       fieldDescriptor& fd = fs.field_descriptor();
  1343       f(&fd, mirror, CHECK);
  1349 static int compare_fields_by_offset(int* a, int* b) {
  1350   return a[0] - b[0];
  1353 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
  1354   InstanceKlass* super = superklass();
  1355   if (super != NULL) {
  1356     super->do_nonstatic_fields(cl);
  1358   fieldDescriptor fd;
  1359   int length = java_fields_count();
  1360   // In DebugInfo nonstatic fields are sorted by offset.
  1361   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
  1362   int j = 0;
  1363   for (int i = 0; i < length; i += 1) {
  1364     fd.reinitialize(this, i);
  1365     if (!fd.is_static()) {
  1366       fields_sorted[j + 0] = fd.offset();
  1367       fields_sorted[j + 1] = i;
  1368       j += 2;
  1371   if (j > 0) {
  1372     length = j;
  1373     // _sort_Fn is defined in growableArray.hpp.
  1374     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
  1375     for (int i = 0; i < length; i += 2) {
  1376       fd.reinitialize(this, fields_sorted[i + 1]);
  1377       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
  1378       cl->do_field(&fd);
  1381   FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
  1385 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
  1386   if (array_klasses() != NULL)
  1387     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
  1390 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
  1391   if (array_klasses() != NULL)
  1392     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
  1395 #ifdef ASSERT
  1396 static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
  1397   int len = methods->length();
  1398   for (int index = 0; index < len; index++) {
  1399     Method* m = methods->at(index);
  1400     assert(m->is_method(), "must be method");
  1401     if (m->signature() == signature && m->name() == name) {
  1402        return index;
  1405   return -1;
  1407 #endif
  1409 static int binary_search(Array<Method*>* methods, Symbol* name) {
  1410   int len = methods->length();
  1411   // methods are sorted, so do binary search
  1412   int l = 0;
  1413   int h = len - 1;
  1414   while (l <= h) {
  1415     int mid = (l + h) >> 1;
  1416     Method* m = methods->at(mid);
  1417     assert(m->is_method(), "must be method");
  1418     int res = m->name()->fast_compare(name);
  1419     if (res == 0) {
  1420       return mid;
  1421     } else if (res < 0) {
  1422       l = mid + 1;
  1423     } else {
  1424       h = mid - 1;
  1427   return -1;
  1430 // find_method looks up the name/signature in the local methods array
  1431 Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
  1432   return InstanceKlass::find_method(methods(), name, signature);
  1435 // find_instance_method looks up the name/signature in the local methods array
  1436 // and skips over static methods
  1437 Method* InstanceKlass::find_instance_method(
  1438     Array<Method*>* methods, Symbol* name, Symbol* signature) {
  1439   Method* meth = InstanceKlass::find_method(methods, name, signature);
  1440   if (meth != NULL && meth->is_static()) {
  1441       meth = NULL;
  1443   return meth;
  1446 // find_method looks up the name/signature in the local methods array
  1447 Method* InstanceKlass::find_method(
  1448     Array<Method*>* methods, Symbol* name, Symbol* signature) {
  1449   int hit = find_method_index(methods, name, signature);
  1450   return hit >= 0 ? methods->at(hit): NULL;
  1453 // Used directly for default_methods to find the index into the
  1454 // default_vtable_indices, and indirectly by find_method
  1455 // find_method_index looks in the local methods array to return the index
  1456 // of the matching name/signature
  1457 int InstanceKlass::find_method_index(
  1458     Array<Method*>* methods, Symbol* name, Symbol* signature) {
  1459   int hit = binary_search(methods, name);
  1460   if (hit != -1) {
  1461     Method* m = methods->at(hit);
  1462     // Do linear search to find matching signature.  First, quick check
  1463     // for common case
  1464     if (m->signature() == signature) return hit;
  1465     // search downwards through overloaded methods
  1466     int i;
  1467     for (i = hit - 1; i >= 0; --i) {
  1468         Method* m = methods->at(i);
  1469         assert(m->is_method(), "must be method");
  1470         if (m->name() != name) break;
  1471         if (m->signature() == signature) return i;
  1473     // search upwards
  1474     for (i = hit + 1; i < methods->length(); ++i) {
  1475         Method* m = methods->at(i);
  1476         assert(m->is_method(), "must be method");
  1477         if (m->name() != name) break;
  1478         if (m->signature() == signature) return i;
  1480     // not found
  1481 #ifdef ASSERT
  1482     int index = linear_search(methods, name, signature);
  1483     assert(index == -1, err_msg("binary search should have found entry %d", index));
  1484 #endif
  1486   return -1;
  1488 int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
  1489   return find_method_by_name(methods(), name, end);
  1492 int InstanceKlass::find_method_by_name(
  1493     Array<Method*>* methods, Symbol* name, int* end_ptr) {
  1494   assert(end_ptr != NULL, "just checking");
  1495   int start = binary_search(methods, name);
  1496   int end = start + 1;
  1497   if (start != -1) {
  1498     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
  1499     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
  1500     *end_ptr = end;
  1501     return start;
  1503   return -1;
  1506 // uncached_lookup_method searches both the local class methods array and all
  1507 // superclasses methods arrays, skipping any overpass methods in superclasses.
  1508 Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
  1509   Klass* klass = const_cast<InstanceKlass*>(this);
  1510   bool dont_ignore_overpasses = true;  // For the class being searched, find its overpasses.
  1511   while (klass != NULL) {
  1512     Method* method = InstanceKlass::cast(klass)->find_method(name, signature);
  1513     if ((method != NULL) && (dont_ignore_overpasses || !method->is_overpass())) {
  1514       return method;
  1516     klass = InstanceKlass::cast(klass)->super();
  1517     dont_ignore_overpasses = false;  // Ignore overpass methods in all superclasses.
  1519   return NULL;
  1522 // lookup a method in the default methods list then in all transitive interfaces
  1523 // Do NOT return private or static methods
  1524 Method* InstanceKlass::lookup_method_in_ordered_interfaces(Symbol* name,
  1525                                                          Symbol* signature) const {
  1526   Method* m = NULL;
  1527   if (default_methods() != NULL) {
  1528     m = find_method(default_methods(), name, signature);
  1530   // Look up interfaces
  1531   if (m == NULL) {
  1532     m = lookup_method_in_all_interfaces(name, signature, false);
  1534   return m;
  1537 // lookup a method in all the interfaces that this class implements
  1538 // Do NOT return private or static methods, new in JDK8 which are not externally visible
  1539 // They should only be found in the initial InterfaceMethodRef
  1540 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
  1541                                                        Symbol* signature,
  1542                                                        bool skip_default_methods) const {
  1543   Array<Klass*>* all_ifs = transitive_interfaces();
  1544   int num_ifs = all_ifs->length();
  1545   InstanceKlass *ik = NULL;
  1546   for (int i = 0; i < num_ifs; i++) {
  1547     ik = InstanceKlass::cast(all_ifs->at(i));
  1548     Method* m = ik->lookup_method(name, signature);
  1549     if (m != NULL && m->is_public() && !m->is_static() &&
  1550         (!skip_default_methods || !m->is_default_method())) {
  1551       return m;
  1554   return NULL;
  1557 /* jni_id_for_impl for jfieldIds only */
  1558 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
  1559   MutexLocker ml(JfieldIdCreation_lock);
  1560   // Retry lookup after we got the lock
  1561   JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
  1562   if (probe == NULL) {
  1563     // Slow case, allocate new static field identifier
  1564     probe = new JNIid(this_oop(), offset, this_oop->jni_ids());
  1565     this_oop->set_jni_ids(probe);
  1567   return probe;
  1571 /* jni_id_for for jfieldIds only */
  1572 JNIid* InstanceKlass::jni_id_for(int offset) {
  1573   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
  1574   if (probe == NULL) {
  1575     probe = jni_id_for_impl(this, offset);
  1577   return probe;
  1580 u2 InstanceKlass::enclosing_method_data(int offset) {
  1581   Array<jushort>* inner_class_list = inner_classes();
  1582   if (inner_class_list == NULL) {
  1583     return 0;
  1585   int length = inner_class_list->length();
  1586   if (length % inner_class_next_offset == 0) {
  1587     return 0;
  1588   } else {
  1589     int index = length - enclosing_method_attribute_size;
  1590     assert(offset < enclosing_method_attribute_size, "invalid offset");
  1591     return inner_class_list->at(index + offset);
  1595 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
  1596                                                  u2 method_index) {
  1597   Array<jushort>* inner_class_list = inner_classes();
  1598   assert (inner_class_list != NULL, "_inner_classes list is not set up");
  1599   int length = inner_class_list->length();
  1600   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
  1601     int index = length - enclosing_method_attribute_size;
  1602     inner_class_list->at_put(
  1603       index + enclosing_method_class_index_offset, class_index);
  1604     inner_class_list->at_put(
  1605       index + enclosing_method_method_index_offset, method_index);
  1609 // Lookup or create a jmethodID.
  1610 // This code is called by the VMThread and JavaThreads so the
  1611 // locking has to be done very carefully to avoid deadlocks
  1612 // and/or other cache consistency problems.
  1613 //
  1614 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
  1615   size_t idnum = (size_t)method_h->method_idnum();
  1616   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
  1617   size_t length = 0;
  1618   jmethodID id = NULL;
  1620   // We use a double-check locking idiom here because this cache is
  1621   // performance sensitive. In the normal system, this cache only
  1622   // transitions from NULL to non-NULL which is safe because we use
  1623   // release_set_methods_jmethod_ids() to advertise the new cache.
  1624   // A partially constructed cache should never be seen by a racing
  1625   // thread. We also use release_store_ptr() to save a new jmethodID
  1626   // in the cache so a partially constructed jmethodID should never be
  1627   // seen either. Cache reads of existing jmethodIDs proceed without a
  1628   // lock, but cache writes of a new jmethodID requires uniqueness and
  1629   // creation of the cache itself requires no leaks so a lock is
  1630   // generally acquired in those two cases.
  1631   //
  1632   // If the RedefineClasses() API has been used, then this cache can
  1633   // grow and we'll have transitions from non-NULL to bigger non-NULL.
  1634   // Cache creation requires no leaks and we require safety between all
  1635   // cache accesses and freeing of the old cache so a lock is generally
  1636   // acquired when the RedefineClasses() API has been used.
  1638   if (jmeths != NULL) {
  1639     // the cache already exists
  1640     if (!ik_h->idnum_can_increment()) {
  1641       // the cache can't grow so we can just get the current values
  1642       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1643     } else {
  1644       // cache can grow so we have to be more careful
  1645       if (Threads::number_of_threads() == 0 ||
  1646           SafepointSynchronize::is_at_safepoint()) {
  1647         // we're single threaded or at a safepoint - no locking needed
  1648         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1649       } else {
  1650         MutexLocker ml(JmethodIdCreation_lock);
  1651         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1655   // implied else:
  1656   // we need to allocate a cache so default length and id values are good
  1658   if (jmeths == NULL ||   // no cache yet
  1659       length <= idnum ||  // cache is too short
  1660       id == NULL) {       // cache doesn't contain entry
  1662     // This function can be called by the VMThread so we have to do all
  1663     // things that might block on a safepoint before grabbing the lock.
  1664     // Otherwise, we can deadlock with the VMThread or have a cache
  1665     // consistency issue. These vars keep track of what we might have
  1666     // to free after the lock is dropped.
  1667     jmethodID  to_dealloc_id     = NULL;
  1668     jmethodID* to_dealloc_jmeths = NULL;
  1670     // may not allocate new_jmeths or use it if we allocate it
  1671     jmethodID* new_jmeths = NULL;
  1672     if (length <= idnum) {
  1673       // allocate a new cache that might be used
  1674       size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
  1675       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
  1676       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
  1677       // cache size is stored in element[0], other elements offset by one
  1678       new_jmeths[0] = (jmethodID)size;
  1681     // allocate a new jmethodID that might be used
  1682     jmethodID new_id = NULL;
  1683     if (method_h->is_old() && !method_h->is_obsolete()) {
  1684       // The method passed in is old (but not obsolete), we need to use the current version
  1685       Method* current_method = ik_h->method_with_idnum((int)idnum);
  1686       assert(current_method != NULL, "old and but not obsolete, so should exist");
  1687       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
  1688     } else {
  1689       // It is the current version of the method or an obsolete method,
  1690       // use the version passed in
  1691       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
  1694     if (Threads::number_of_threads() == 0 ||
  1695         SafepointSynchronize::is_at_safepoint()) {
  1696       // we're single threaded or at a safepoint - no locking needed
  1697       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
  1698                                           &to_dealloc_id, &to_dealloc_jmeths);
  1699     } else {
  1700       MutexLocker ml(JmethodIdCreation_lock);
  1701       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
  1702                                           &to_dealloc_id, &to_dealloc_jmeths);
  1705     // The lock has been dropped so we can free resources.
  1706     // Free up either the old cache or the new cache if we allocated one.
  1707     if (to_dealloc_jmeths != NULL) {
  1708       FreeHeap(to_dealloc_jmeths);
  1710     // free up the new ID since it wasn't needed
  1711     if (to_dealloc_id != NULL) {
  1712       Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
  1715   return id;
  1719 // Common code to fetch the jmethodID from the cache or update the
  1720 // cache with the new jmethodID. This function should never do anything
  1721 // that causes the caller to go to a safepoint or we can deadlock with
  1722 // the VMThread or have cache consistency issues.
  1723 //
  1724 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
  1725             instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
  1726             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
  1727             jmethodID** to_dealloc_jmeths_p) {
  1728   assert(new_id != NULL, "sanity check");
  1729   assert(to_dealloc_id_p != NULL, "sanity check");
  1730   assert(to_dealloc_jmeths_p != NULL, "sanity check");
  1731   assert(Threads::number_of_threads() == 0 ||
  1732          SafepointSynchronize::is_at_safepoint() ||
  1733          JmethodIdCreation_lock->owned_by_self(), "sanity check");
  1735   // reacquire the cache - we are locked, single threaded or at a safepoint
  1736   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
  1737   jmethodID  id     = NULL;
  1738   size_t     length = 0;
  1740   if (jmeths == NULL ||                         // no cache yet
  1741       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
  1742     if (jmeths != NULL) {
  1743       // copy any existing entries from the old cache
  1744       for (size_t index = 0; index < length; index++) {
  1745         new_jmeths[index+1] = jmeths[index+1];
  1747       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
  1749     ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
  1750   } else {
  1751     // fetch jmethodID (if any) from the existing cache
  1752     id = jmeths[idnum+1];
  1753     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
  1755   if (id == NULL) {
  1756     // No matching jmethodID in the existing cache or we have a new
  1757     // cache or we just grew the cache. This cache write is done here
  1758     // by the first thread to win the foot race because a jmethodID
  1759     // needs to be unique once it is generally available.
  1760     id = new_id;
  1762     // The jmethodID cache can be read while unlocked so we have to
  1763     // make sure the new jmethodID is complete before installing it
  1764     // in the cache.
  1765     OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
  1766   } else {
  1767     *to_dealloc_id_p = new_id; // save new id for later delete
  1769   return id;
  1773 // Common code to get the jmethodID cache length and the jmethodID
  1774 // value at index idnum if there is one.
  1775 //
  1776 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
  1777        size_t idnum, size_t *length_p, jmethodID* id_p) {
  1778   assert(cache != NULL, "sanity check");
  1779   assert(length_p != NULL, "sanity check");
  1780   assert(id_p != NULL, "sanity check");
  1782   // cache size is stored in element[0], other elements offset by one
  1783   *length_p = (size_t)cache[0];
  1784   if (*length_p <= idnum) {  // cache is too short
  1785     *id_p = NULL;
  1786   } else {
  1787     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
  1792 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
  1793 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
  1794   size_t idnum = (size_t)method->method_idnum();
  1795   jmethodID* jmeths = methods_jmethod_ids_acquire();
  1796   size_t length;                                // length assigned as debugging crumb
  1797   jmethodID id = NULL;
  1798   if (jmeths != NULL &&                         // If there is a cache
  1799       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
  1800     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
  1802   return id;
  1806 //
  1807 // Walk the list of dependent nmethods searching for nmethods which
  1808 // are dependent on the changes that were passed in and mark them for
  1809 // deoptimization.  Returns the number of nmethods found.
  1810 //
  1811 int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
  1812   assert_locked_or_safepoint(CodeCache_lock);
  1813   int found = 0;
  1814   nmethodBucket* b = _dependencies;
  1815   while (b != NULL) {
  1816     nmethod* nm = b->get_nmethod();
  1817     // since dependencies aren't removed until an nmethod becomes a zombie,
  1818     // the dependency list may contain nmethods which aren't alive.
  1819     if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
  1820       if (TraceDependencies) {
  1821         ResourceMark rm;
  1822         tty->print_cr("Marked for deoptimization");
  1823         tty->print_cr("  context = %s", this->external_name());
  1824         changes.print();
  1825         nm->print();
  1826         nm->print_dependencies();
  1828       nm->mark_for_deoptimization();
  1829       found++;
  1831     b = b->next();
  1833   return found;
  1837 //
  1838 // Add an nmethodBucket to the list of dependencies for this nmethod.
  1839 // It's possible that an nmethod has multiple dependencies on this klass
  1840 // so a count is kept for each bucket to guarantee that creation and
  1841 // deletion of dependencies is consistent.
  1842 //
  1843 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
  1844   assert_locked_or_safepoint(CodeCache_lock);
  1845   nmethodBucket* b = _dependencies;
  1846   nmethodBucket* last = NULL;
  1847   while (b != NULL) {
  1848     if (nm == b->get_nmethod()) {
  1849       b->increment();
  1850       return;
  1852     b = b->next();
  1854   _dependencies = new nmethodBucket(nm, _dependencies);
  1858 //
  1859 // Decrement count of the nmethod in the dependency list and remove
  1860 // the bucket competely when the count goes to 0.  This method must
  1861 // find a corresponding bucket otherwise there's a bug in the
  1862 // recording of dependecies.
  1863 //
  1864 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
  1865   assert_locked_or_safepoint(CodeCache_lock);
  1866   nmethodBucket* b = _dependencies;
  1867   nmethodBucket* last = NULL;
  1868   while (b != NULL) {
  1869     if (nm == b->get_nmethod()) {
  1870       if (b->decrement() == 0) {
  1871         if (last == NULL) {
  1872           _dependencies = b->next();
  1873         } else {
  1874           last->set_next(b->next());
  1876         delete b;
  1878       return;
  1880     last = b;
  1881     b = b->next();
  1883 #ifdef ASSERT
  1884   tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
  1885   nm->print();
  1886 #endif // ASSERT
  1887   ShouldNotReachHere();
  1891 #ifndef PRODUCT
  1892 void InstanceKlass::print_dependent_nmethods(bool verbose) {
  1893   nmethodBucket* b = _dependencies;
  1894   int idx = 0;
  1895   while (b != NULL) {
  1896     nmethod* nm = b->get_nmethod();
  1897     tty->print("[%d] count=%d { ", idx++, b->count());
  1898     if (!verbose) {
  1899       nm->print_on(tty, "nmethod");
  1900       tty->print_cr(" } ");
  1901     } else {
  1902       nm->print();
  1903       nm->print_dependencies();
  1904       tty->print_cr("--- } ");
  1906     b = b->next();
  1911 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
  1912   nmethodBucket* b = _dependencies;
  1913   while (b != NULL) {
  1914     if (nm == b->get_nmethod()) {
  1915       return true;
  1917     b = b->next();
  1919   return false;
  1921 #endif //PRODUCT
  1924 // Garbage collection
  1926 #ifdef ASSERT
  1927 template <class T> void assert_is_in(T *p) {
  1928   T heap_oop = oopDesc::load_heap_oop(p);
  1929   if (!oopDesc::is_null(heap_oop)) {
  1930     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1931     assert(Universe::heap()->is_in(o), "should be in heap");
  1934 template <class T> void assert_is_in_closed_subset(T *p) {
  1935   T heap_oop = oopDesc::load_heap_oop(p);
  1936   if (!oopDesc::is_null(heap_oop)) {
  1937     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1938     assert(Universe::heap()->is_in_closed_subset(o),
  1939            err_msg("should be in closed *p " INTPTR_FORMAT " " INTPTR_FORMAT, (address)p, (address)o));
  1942 template <class T> void assert_is_in_reserved(T *p) {
  1943   T heap_oop = oopDesc::load_heap_oop(p);
  1944   if (!oopDesc::is_null(heap_oop)) {
  1945     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1946     assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
  1949 template <class T> void assert_nothing(T *p) {}
  1951 #else
  1952 template <class T> void assert_is_in(T *p) {}
  1953 template <class T> void assert_is_in_closed_subset(T *p) {}
  1954 template <class T> void assert_is_in_reserved(T *p) {}
  1955 template <class T> void assert_nothing(T *p) {}
  1956 #endif // ASSERT
  1958 //
  1959 // Macros that iterate over areas of oops which are specialized on type of
  1960 // oop pointer either narrow or wide, depending on UseCompressedOops
  1961 //
  1962 // Parameters are:
  1963 //   T         - type of oop to point to (either oop or narrowOop)
  1964 //   start_p   - starting pointer for region to iterate over
  1965 //   count     - number of oops or narrowOops to iterate over
  1966 //   do_oop    - action to perform on each oop (it's arbitrary C code which
  1967 //               makes it more efficient to put in a macro rather than making
  1968 //               it a template function)
  1969 //   assert_fn - assert function which is template function because performance
  1970 //               doesn't matter when enabled.
  1971 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
  1972   T, start_p, count, do_oop,                \
  1973   assert_fn)                                \
  1974 {                                           \
  1975   T* p         = (T*)(start_p);             \
  1976   T* const end = p + (count);               \
  1977   while (p < end) {                         \
  1978     (assert_fn)(p);                         \
  1979     do_oop;                                 \
  1980     ++p;                                    \
  1981   }                                         \
  1984 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
  1985   T, start_p, count, do_oop,                \
  1986   assert_fn)                                \
  1987 {                                           \
  1988   T* const start = (T*)(start_p);           \
  1989   T*       p     = start + (count);         \
  1990   while (start < p) {                       \
  1991     --p;                                    \
  1992     (assert_fn)(p);                         \
  1993     do_oop;                                 \
  1994   }                                         \
  1997 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
  1998   T, start_p, count, low, high,             \
  1999   do_oop, assert_fn)                        \
  2000 {                                           \
  2001   T* const l = (T*)(low);                   \
  2002   T* const h = (T*)(high);                  \
  2003   assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
  2004          mask_bits((intptr_t)h, sizeof(T)-1) == 0,   \
  2005          "bounded region must be properly aligned"); \
  2006   T* p       = (T*)(start_p);               \
  2007   T* end     = p + (count);                 \
  2008   if (p < l) p = l;                         \
  2009   if (end > h) end = h;                     \
  2010   while (p < end) {                         \
  2011     (assert_fn)(p);                         \
  2012     do_oop;                                 \
  2013     ++p;                                    \
  2014   }                                         \
  2018 // The following macros call specialized macros, passing either oop or
  2019 // narrowOop as the specialization type.  These test the UseCompressedOops
  2020 // flag.
  2021 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn)            \
  2022 {                                                                        \
  2023   /* Compute oopmap block range. The common case                         \
  2024      is nonstatic_oop_map_size == 1. */                                  \
  2025   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  2026   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
  2027   if (UseCompressedOops) {                                               \
  2028     while (map < end_map) {                                              \
  2029       InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop,                   \
  2030         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  2031         do_oop, assert_fn)                                               \
  2032       ++map;                                                             \
  2033     }                                                                    \
  2034   } else {                                                               \
  2035     while (map < end_map) {                                              \
  2036       InstanceKlass_SPECIALIZED_OOP_ITERATE(oop,                         \
  2037         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  2038         do_oop, assert_fn)                                               \
  2039       ++map;                                                             \
  2040     }                                                                    \
  2041   }                                                                      \
  2044 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn)    \
  2045 {                                                                        \
  2046   OopMapBlock* const start_map = start_of_nonstatic_oop_maps();          \
  2047   OopMapBlock* map             = start_map + nonstatic_oop_map_count();  \
  2048   if (UseCompressedOops) {                                               \
  2049     while (start_map < map) {                                            \
  2050       --map;                                                             \
  2051       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop,           \
  2052         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  2053         do_oop, assert_fn)                                               \
  2054     }                                                                    \
  2055   } else {                                                               \
  2056     while (start_map < map) {                                            \
  2057       --map;                                                             \
  2058       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop,                 \
  2059         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  2060         do_oop, assert_fn)                                               \
  2061     }                                                                    \
  2062   }                                                                      \
  2065 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop,    \
  2066                                               assert_fn)                 \
  2067 {                                                                        \
  2068   /* Compute oopmap block range. The common case is                      \
  2069      nonstatic_oop_map_size == 1, so we accept the                       \
  2070      usually non-existent extra overhead of examining                    \
  2071      all the maps. */                                                    \
  2072   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  2073   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
  2074   if (UseCompressedOops) {                                               \
  2075     while (map < end_map) {                                              \
  2076       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop,           \
  2077         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  2078         low, high,                                                       \
  2079         do_oop, assert_fn)                                               \
  2080       ++map;                                                             \
  2081     }                                                                    \
  2082   } else {                                                               \
  2083     while (map < end_map) {                                              \
  2084       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop,                 \
  2085         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  2086         low, high,                                                       \
  2087         do_oop, assert_fn)                                               \
  2088       ++map;                                                             \
  2089     }                                                                    \
  2090   }                                                                      \
  2093 void InstanceKlass::oop_follow_contents(oop obj) {
  2094   assert(obj != NULL, "can't follow the content of NULL object");
  2095   MarkSweep::follow_klass(obj->klass());
  2096   InstanceKlass_OOP_MAP_ITERATE( \
  2097     obj, \
  2098     MarkSweep::mark_and_push(p), \
  2099     assert_is_in_closed_subset)
  2102 #if INCLUDE_ALL_GCS
  2103 void InstanceKlass::oop_follow_contents(ParCompactionManager* cm,
  2104                                         oop obj) {
  2105   assert(obj != NULL, "can't follow the content of NULL object");
  2106   PSParallelCompact::follow_klass(cm, obj->klass());
  2107   // Only mark the header and let the scan of the meta-data mark
  2108   // everything else.
  2109   InstanceKlass_OOP_MAP_ITERATE( \
  2110     obj, \
  2111     PSParallelCompact::mark_and_push(cm, p), \
  2112     assert_is_in)
  2114 #endif // INCLUDE_ALL_GCS
  2116 // closure's do_metadata() method dictates whether the given closure should be
  2117 // applied to the klass ptr in the object header.
  2119 #define if_do_metadata_checked(closure, nv_suffix)                    \
  2120   /* Make sure the non-virtual and the virtual versions match. */     \
  2121   assert(closure->do_metadata##nv_suffix() == closure->do_metadata(), \
  2122       "Inconsistency in do_metadata");                                \
  2123   if (closure->do_metadata##nv_suffix())
  2125 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)        \
  2127 int InstanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
  2128   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  2129   /* header */                                                          \
  2130   if_do_metadata_checked(closure, nv_suffix) {                          \
  2131     closure->do_klass##nv_suffix(obj->klass());                         \
  2132   }                                                                     \
  2133   InstanceKlass_OOP_MAP_ITERATE(                                        \
  2134     obj,                                                                \
  2135     SpecializationStats::                                               \
  2136       record_do_oop_call##nv_suffix(SpecializationStats::ik);           \
  2137     (closure)->do_oop##nv_suffix(p),                                    \
  2138     assert_is_in_closed_subset)                                         \
  2139   return size_helper();                                                 \
  2142 #if INCLUDE_ALL_GCS
  2143 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
  2145 int InstanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj,                \
  2146                                               OopClosureType* closure) {        \
  2147   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
  2148   /* header */                                                                  \
  2149   if_do_metadata_checked(closure, nv_suffix) {                                  \
  2150     closure->do_klass##nv_suffix(obj->klass());                                 \
  2151   }                                                                             \
  2152   /* instance variables */                                                      \
  2153   InstanceKlass_OOP_MAP_REVERSE_ITERATE(                                        \
  2154     obj,                                                                        \
  2155     SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
  2156     (closure)->do_oop##nv_suffix(p),                                            \
  2157     assert_is_in_closed_subset)                                                 \
  2158    return size_helper();                                                        \
  2160 #endif // INCLUDE_ALL_GCS
  2162 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
  2164 int InstanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj,              \
  2165                                                   OopClosureType* closure, \
  2166                                                   MemRegion mr) {          \
  2167   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  2168   if_do_metadata_checked(closure, nv_suffix) {                           \
  2169     if (mr.contains(obj)) {                                              \
  2170       closure->do_klass##nv_suffix(obj->klass());                        \
  2171     }                                                                    \
  2172   }                                                                      \
  2173   InstanceKlass_BOUNDED_OOP_MAP_ITERATE(                                 \
  2174     obj, mr.start(), mr.end(),                                           \
  2175     (closure)->do_oop##nv_suffix(p),                                     \
  2176     assert_is_in_closed_subset)                                          \
  2177   return size_helper();                                                  \
  2180 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
  2181 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
  2182 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
  2183 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
  2184 #if INCLUDE_ALL_GCS
  2185 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
  2186 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
  2187 #endif // INCLUDE_ALL_GCS
  2189 int InstanceKlass::oop_adjust_pointers(oop obj) {
  2190   int size = size_helper();
  2191   InstanceKlass_OOP_MAP_ITERATE( \
  2192     obj, \
  2193     MarkSweep::adjust_pointer(p), \
  2194     assert_is_in)
  2195   return size;
  2198 #if INCLUDE_ALL_GCS
  2199 void InstanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
  2200   InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
  2201     obj, \
  2202     if (PSScavenge::should_scavenge(p)) { \
  2203       pm->claim_or_forward_depth(p); \
  2204     }, \
  2205     assert_nothing )
  2208 int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
  2209   int size = size_helper();
  2210   InstanceKlass_OOP_MAP_ITERATE( \
  2211     obj, \
  2212     PSParallelCompact::adjust_pointer(p), \
  2213     assert_is_in)
  2214   return size;
  2217 #endif // INCLUDE_ALL_GCS
  2219 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
  2220   assert(is_loader_alive(is_alive), "this klass should be live");
  2221   if (is_interface()) {
  2222     if (ClassUnloading) {
  2223       Klass* impl = implementor();
  2224       if (impl != NULL) {
  2225         if (!impl->is_loader_alive(is_alive)) {
  2226           // remove this guy
  2227           Klass** klass = adr_implementor();
  2228           assert(klass != NULL, "null klass");
  2229           if (klass != NULL) {
  2230             *klass = NULL;
  2238 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
  2239   for (int m = 0; m < methods()->length(); m++) {
  2240     MethodData* mdo = methods()->at(m)->method_data();
  2241     if (mdo != NULL) {
  2242       mdo->clean_method_data(is_alive);
  2248 static void remove_unshareable_in_class(Klass* k) {
  2249   // remove klass's unshareable info
  2250   k->remove_unshareable_info();
  2253 void InstanceKlass::remove_unshareable_info() {
  2254   Klass::remove_unshareable_info();
  2255   // Unlink the class
  2256   if (is_linked()) {
  2257     unlink_class();
  2259   init_implementor();
  2261   constants()->remove_unshareable_info();
  2263   for (int i = 0; i < methods()->length(); i++) {
  2264     Method* m = methods()->at(i);
  2265     m->remove_unshareable_info();
  2268   // do array classes also.
  2269   array_klasses_do(remove_unshareable_in_class);
  2272 void restore_unshareable_in_class(Klass* k, TRAPS) {
  2273   k->restore_unshareable_info(CHECK);
  2276 void InstanceKlass::restore_unshareable_info(TRAPS) {
  2277   Klass::restore_unshareable_info(CHECK);
  2278   instanceKlassHandle ik(THREAD, this);
  2280   Array<Method*>* methods = ik->methods();
  2281   int num_methods = methods->length();
  2282   for (int index2 = 0; index2 < num_methods; ++index2) {
  2283     methodHandle m(THREAD, methods->at(index2));
  2284     m->restore_unshareable_info(CHECK);
  2286   if (JvmtiExport::has_redefined_a_class()) {
  2287     // Reinitialize vtable because RedefineClasses may have changed some
  2288     // entries in this vtable for super classes so the CDS vtable might
  2289     // point to old or obsolete entries.  RedefineClasses doesn't fix up
  2290     // vtables in the shared system dictionary, only the main one.
  2291     // It also redefines the itable too so fix that too.
  2292     ResourceMark rm(THREAD);
  2293     ik->vtable()->initialize_vtable(false, CHECK);
  2294     ik->itable()->initialize_itable(false, CHECK);
  2297   // restore constant pool resolved references
  2298   ik->constants()->restore_unshareable_info(CHECK);
  2300   ik->array_klasses_do(restore_unshareable_in_class, CHECK);
  2303 static void clear_all_breakpoints(Method* m) {
  2304   m->clear_all_breakpoints();
  2308 void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
  2309   // notify the debugger
  2310   if (JvmtiExport::should_post_class_unload()) {
  2311     JvmtiExport::post_class_unload(ik);
  2314   // notify ClassLoadingService of class unload
  2315   ClassLoadingService::notify_class_unloaded(ik);
  2318 void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
  2319   // Clean up C heap
  2320   ik->release_C_heap_structures();
  2321   ik->constants()->release_C_heap_structures();
  2324 void InstanceKlass::release_C_heap_structures() {
  2326   // Can't release the constant pool here because the constant pool can be
  2327   // deallocated separately from the InstanceKlass for default methods and
  2328   // redefine classes.
  2330   // Deallocate oop map cache
  2331   if (_oop_map_cache != NULL) {
  2332     delete _oop_map_cache;
  2333     _oop_map_cache = NULL;
  2336   // Deallocate JNI identifiers for jfieldIDs
  2337   JNIid::deallocate(jni_ids());
  2338   set_jni_ids(NULL);
  2340   jmethodID* jmeths = methods_jmethod_ids_acquire();
  2341   if (jmeths != (jmethodID*)NULL) {
  2342     release_set_methods_jmethod_ids(NULL);
  2343     FreeHeap(jmeths);
  2346   // Deallocate MemberNameTable
  2348     Mutex* lock_or_null = SafepointSynchronize::is_at_safepoint() ? NULL : MemberNameTable_lock;
  2349     MutexLockerEx ml(lock_or_null, Mutex::_no_safepoint_check_flag);
  2350     MemberNameTable* mnt = member_names();
  2351     if (mnt != NULL) {
  2352       delete mnt;
  2353       set_member_names(NULL);
  2357   // release dependencies
  2358   nmethodBucket* b = _dependencies;
  2359   _dependencies = NULL;
  2360   while (b != NULL) {
  2361     nmethodBucket* next = b->next();
  2362     delete b;
  2363     b = next;
  2366   // Deallocate breakpoint records
  2367   if (breakpoints() != 0x0) {
  2368     methods_do(clear_all_breakpoints);
  2369     assert(breakpoints() == 0x0, "should have cleared breakpoints");
  2372   // deallocate information about previous versions
  2373   if (_previous_versions != NULL) {
  2374     for (int i = _previous_versions->length() - 1; i >= 0; i--) {
  2375       PreviousVersionNode * pv_node = _previous_versions->at(i);
  2376       delete pv_node;
  2378     delete _previous_versions;
  2379     _previous_versions = NULL;
  2382   // deallocate the cached class file
  2383   if (_cached_class_file != NULL) {
  2384     os::free(_cached_class_file, mtClass);
  2385     _cached_class_file = NULL;
  2388   // Decrement symbol reference counts associated with the unloaded class.
  2389   if (_name != NULL) _name->decrement_refcount();
  2390   // unreference array name derived from this class name (arrays of an unloaded
  2391   // class can't be referenced anymore).
  2392   if (_array_name != NULL)  _array_name->decrement_refcount();
  2393   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension, mtClass);
  2395   assert(_total_instanceKlass_count >= 1, "Sanity check");
  2396   Atomic::dec(&_total_instanceKlass_count);
  2399 void InstanceKlass::set_source_debug_extension(char* array, int length) {
  2400   if (array == NULL) {
  2401     _source_debug_extension = NULL;
  2402   } else {
  2403     // Adding one to the attribute length in order to store a null terminator
  2404     // character could cause an overflow because the attribute length is
  2405     // already coded with an u4 in the classfile, but in practice, it's
  2406     // unlikely to happen.
  2407     assert((length+1) > length, "Overflow checking");
  2408     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
  2409     for (int i = 0; i < length; i++) {
  2410       sde[i] = array[i];
  2412     sde[length] = '\0';
  2413     _source_debug_extension = sde;
  2417 address InstanceKlass::static_field_addr(int offset) {
  2418   return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + cast_from_oop<intptr_t>(java_mirror()));
  2422 const char* InstanceKlass::signature_name() const {
  2423   int hash_len = 0;
  2424   char hash_buf[40];
  2426   // If this is an anonymous class, append a hash to make the name unique
  2427   if (is_anonymous()) {
  2428     assert(EnableInvokeDynamic, "EnableInvokeDynamic was not set.");
  2429     intptr_t hash = (java_mirror() != NULL) ? java_mirror()->identity_hash() : 0;
  2430     sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash);
  2431     hash_len = (int)strlen(hash_buf);
  2434   // Get the internal name as a c string
  2435   const char* src = (const char*) (name()->as_C_string());
  2436   const int src_length = (int)strlen(src);
  2438   char* dest = NEW_RESOURCE_ARRAY(char, src_length + hash_len + 3);
  2440   // Add L as type indicator
  2441   int dest_index = 0;
  2442   dest[dest_index++] = 'L';
  2444   // Add the actual class name
  2445   for (int src_index = 0; src_index < src_length; ) {
  2446     dest[dest_index++] = src[src_index++];
  2449   // If we have a hash, append it
  2450   for (int hash_index = 0; hash_index < hash_len; ) {
  2451     dest[dest_index++] = hash_buf[hash_index++];
  2454   // Add the semicolon and the NULL
  2455   dest[dest_index++] = ';';
  2456   dest[dest_index] = '\0';
  2457   return dest;
  2460 // different verisons of is_same_class_package
  2461 bool InstanceKlass::is_same_class_package(Klass* class2) {
  2462   Klass* class1 = this;
  2463   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
  2464   Symbol* classname1 = class1->name();
  2466   if (class2->oop_is_objArray()) {
  2467     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
  2469   oop classloader2;
  2470   if (class2->oop_is_instance()) {
  2471     classloader2 = InstanceKlass::cast(class2)->class_loader();
  2472   } else {
  2473     assert(class2->oop_is_typeArray(), "should be type array");
  2474     classloader2 = NULL;
  2476   Symbol* classname2 = class2->name();
  2478   return InstanceKlass::is_same_class_package(classloader1, classname1,
  2479                                               classloader2, classname2);
  2482 bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
  2483   Klass* class1 = this;
  2484   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
  2485   Symbol* classname1 = class1->name();
  2487   return InstanceKlass::is_same_class_package(classloader1, classname1,
  2488                                               classloader2, classname2);
  2491 // return true if two classes are in the same package, classloader
  2492 // and classname information is enough to determine a class's package
  2493 bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
  2494                                           oop class_loader2, Symbol* class_name2) {
  2495   if (class_loader1 != class_loader2) {
  2496     return false;
  2497   } else if (class_name1 == class_name2) {
  2498     return true;                // skip painful bytewise comparison
  2499   } else {
  2500     ResourceMark rm;
  2502     // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
  2503     // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
  2504     // Otherwise, we just compare jbyte values between the strings.
  2505     const jbyte *name1 = class_name1->base();
  2506     const jbyte *name2 = class_name2->base();
  2508     const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
  2509     const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
  2511     if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
  2512       // One of the two doesn't have a package.  Only return true
  2513       // if the other one also doesn't have a package.
  2514       return last_slash1 == last_slash2;
  2515     } else {
  2516       // Skip over '['s
  2517       if (*name1 == '[') {
  2518         do {
  2519           name1++;
  2520         } while (*name1 == '[');
  2521         if (*name1 != 'L') {
  2522           // Something is terribly wrong.  Shouldn't be here.
  2523           return false;
  2526       if (*name2 == '[') {
  2527         do {
  2528           name2++;
  2529         } while (*name2 == '[');
  2530         if (*name2 != 'L') {
  2531           // Something is terribly wrong.  Shouldn't be here.
  2532           return false;
  2536       // Check that package part is identical
  2537       int length1 = last_slash1 - name1;
  2538       int length2 = last_slash2 - name2;
  2540       return UTF8::equal(name1, length1, name2, length2);
  2545 // Returns true iff super_method can be overridden by a method in targetclassname
  2546 // See JSL 3rd edition 8.4.6.1
  2547 // Assumes name-signature match
  2548 // "this" is InstanceKlass of super_method which must exist
  2549 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
  2550 bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
  2551    // Private methods can not be overridden
  2552    if (super_method->is_private()) {
  2553      return false;
  2555    // If super method is accessible, then override
  2556    if ((super_method->is_protected()) ||
  2557        (super_method->is_public())) {
  2558      return true;
  2560    // Package-private methods are not inherited outside of package
  2561    assert(super_method->is_package_private(), "must be package private");
  2562    return(is_same_class_package(targetclassloader(), targetclassname));
  2565 /* defined for now in jvm.cpp, for historical reasons *--
  2566 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
  2567                                                      Symbol*& simple_name_result, TRAPS) {
  2568   ...
  2570 */
  2572 // tell if two classes have the same enclosing class (at package level)
  2573 bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
  2574                                                 Klass* class2_oop, TRAPS) {
  2575   if (class2_oop == class1())                       return true;
  2576   if (!class2_oop->oop_is_instance())  return false;
  2577   instanceKlassHandle class2(THREAD, class2_oop);
  2579   // must be in same package before we try anything else
  2580   if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
  2581     return false;
  2583   // As long as there is an outer1.getEnclosingClass,
  2584   // shift the search outward.
  2585   instanceKlassHandle outer1 = class1;
  2586   for (;;) {
  2587     // As we walk along, look for equalities between outer1 and class2.
  2588     // Eventually, the walks will terminate as outer1 stops
  2589     // at the top-level class around the original class.
  2590     bool ignore_inner_is_member;
  2591     Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
  2592                                                     CHECK_false);
  2593     if (next == NULL)  break;
  2594     if (next == class2())  return true;
  2595     outer1 = instanceKlassHandle(THREAD, next);
  2598   // Now do the same for class2.
  2599   instanceKlassHandle outer2 = class2;
  2600   for (;;) {
  2601     bool ignore_inner_is_member;
  2602     Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
  2603                                                     CHECK_false);
  2604     if (next == NULL)  break;
  2605     // Might as well check the new outer against all available values.
  2606     if (next == class1())  return true;
  2607     if (next == outer1())  return true;
  2608     outer2 = instanceKlassHandle(THREAD, next);
  2611   // If by this point we have not found an equality between the
  2612   // two classes, we know they are in separate package members.
  2613   return false;
  2617 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
  2618   jint access = access_flags().as_int();
  2620   // But check if it happens to be member class.
  2621   instanceKlassHandle ik(THREAD, this);
  2622   InnerClassesIterator iter(ik);
  2623   for (; !iter.done(); iter.next()) {
  2624     int ioff = iter.inner_class_info_index();
  2625     // Inner class attribute can be zero, skip it.
  2626     // Strange but true:  JVM spec. allows null inner class refs.
  2627     if (ioff == 0) continue;
  2629     // only look at classes that are already loaded
  2630     // since we are looking for the flags for our self.
  2631     Symbol* inner_name = ik->constants()->klass_name_at(ioff);
  2632     if ((ik->name() == inner_name)) {
  2633       // This is really a member class.
  2634       access = iter.inner_access_flags();
  2635       break;
  2638   // Remember to strip ACC_SUPER bit
  2639   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
  2642 jint InstanceKlass::jvmti_class_status() const {
  2643   jint result = 0;
  2645   if (is_linked()) {
  2646     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
  2649   if (is_initialized()) {
  2650     assert(is_linked(), "Class status is not consistent");
  2651     result |= JVMTI_CLASS_STATUS_INITIALIZED;
  2653   if (is_in_error_state()) {
  2654     result |= JVMTI_CLASS_STATUS_ERROR;
  2656   return result;
  2659 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
  2660   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
  2661   int method_table_offset_in_words = ioe->offset()/wordSize;
  2662   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
  2663                        / itableOffsetEntry::size();
  2665   for (int cnt = 0 ; ; cnt ++, ioe ++) {
  2666     // If the interface isn't implemented by the receiver class,
  2667     // the VM should throw IncompatibleClassChangeError.
  2668     if (cnt >= nof_interfaces) {
  2669       THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
  2672     Klass* ik = ioe->interface_klass();
  2673     if (ik == holder) break;
  2676   itableMethodEntry* ime = ioe->first_method_entry(this);
  2677   Method* m = ime[index].method();
  2678   if (m == NULL) {
  2679     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
  2681   return m;
  2685 #if INCLUDE_JVMTI
  2686 // update default_methods for redefineclasses for methods that are
  2687 // not yet in the vtable due to concurrent subclass define and superinterface
  2688 // redefinition
  2689 // Note: those in the vtable, should have been updated via adjust_method_entries
  2690 void InstanceKlass::adjust_default_methods(Method** old_methods, Method** new_methods,
  2691                                            int methods_length, bool* trace_name_printed) {
  2692   // search the default_methods for uses of either obsolete or EMCP methods
  2693   if (default_methods() != NULL) {
  2694     for (int j = 0; j < methods_length; j++) {
  2695       Method* old_method = old_methods[j];
  2696       Method* new_method = new_methods[j];
  2698       for (int index = 0; index < default_methods()->length(); index ++) {
  2699         if (default_methods()->at(index) == old_method) {
  2700           default_methods()->at_put(index, new_method);
  2701           if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
  2702             if (!(*trace_name_printed)) {
  2703               // RC_TRACE_MESG macro has an embedded ResourceMark
  2704               RC_TRACE_MESG(("adjust: klassname=%s default methods from name=%s",
  2705                              external_name(),
  2706                              old_method->method_holder()->external_name()));
  2707               *trace_name_printed = true;
  2709             RC_TRACE(0x00100000, ("default method update: %s(%s) ",
  2710                                   new_method->name()->as_C_string(),
  2711                                   new_method->signature()->as_C_string()));
  2718 #endif // INCLUDE_JVMTI
  2720 // On-stack replacement stuff
  2721 void InstanceKlass::add_osr_nmethod(nmethod* n) {
  2722   // only one compilation can be active
  2723   NEEDS_CLEANUP
  2724   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2725   OsrList_lock->lock_without_safepoint_check();
  2726   assert(n->is_osr_method(), "wrong kind of nmethod");
  2727   n->set_osr_link(osr_nmethods_head());
  2728   set_osr_nmethods_head(n);
  2729   // Raise the highest osr level if necessary
  2730   if (TieredCompilation) {
  2731     Method* m = n->method();
  2732     m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
  2734   // Remember to unlock again
  2735   OsrList_lock->unlock();
  2737   // Get rid of the osr methods for the same bci that have lower levels.
  2738   if (TieredCompilation) {
  2739     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
  2740       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
  2741       if (inv != NULL && inv->is_in_use()) {
  2742         inv->make_not_entrant();
  2749 void InstanceKlass::remove_osr_nmethod(nmethod* n) {
  2750   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2751   OsrList_lock->lock_without_safepoint_check();
  2752   assert(n->is_osr_method(), "wrong kind of nmethod");
  2753   nmethod* last = NULL;
  2754   nmethod* cur  = osr_nmethods_head();
  2755   int max_level = CompLevel_none;  // Find the max comp level excluding n
  2756   Method* m = n->method();
  2757   // Search for match
  2758   while(cur != NULL && cur != n) {
  2759     if (TieredCompilation) {
  2760       // Find max level before n
  2761       max_level = MAX2(max_level, cur->comp_level());
  2763     last = cur;
  2764     cur = cur->osr_link();
  2766   nmethod* next = NULL;
  2767   if (cur == n) {
  2768     next = cur->osr_link();
  2769     if (last == NULL) {
  2770       // Remove first element
  2771       set_osr_nmethods_head(next);
  2772     } else {
  2773       last->set_osr_link(next);
  2776   n->set_osr_link(NULL);
  2777   if (TieredCompilation) {
  2778     cur = next;
  2779     while (cur != NULL) {
  2780       // Find max level after n
  2781       max_level = MAX2(max_level, cur->comp_level());
  2782       cur = cur->osr_link();
  2784     m->set_highest_osr_comp_level(max_level);
  2786   // Remember to unlock again
  2787   OsrList_lock->unlock();
  2790 nmethod* InstanceKlass::lookup_osr_nmethod(const Method* m, int bci, int comp_level, bool match_level) const {
  2791   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2792   OsrList_lock->lock_without_safepoint_check();
  2793   nmethod* osr = osr_nmethods_head();
  2794   nmethod* best = NULL;
  2795   while (osr != NULL) {
  2796     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
  2797     // There can be a time when a c1 osr method exists but we are waiting
  2798     // for a c2 version. When c2 completes its osr nmethod we will trash
  2799     // the c1 version and only be able to find the c2 version. However
  2800     // while we overflow in the c1 code at back branches we don't want to
  2801     // try and switch to the same code as we are already running
  2803     if (osr->method() == m &&
  2804         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
  2805       if (match_level) {
  2806         if (osr->comp_level() == comp_level) {
  2807           // Found a match - return it.
  2808           OsrList_lock->unlock();
  2809           return osr;
  2811       } else {
  2812         if (best == NULL || (osr->comp_level() > best->comp_level())) {
  2813           if (osr->comp_level() == CompLevel_highest_tier) {
  2814             // Found the best possible - return it.
  2815             OsrList_lock->unlock();
  2816             return osr;
  2818           best = osr;
  2822     osr = osr->osr_link();
  2824   OsrList_lock->unlock();
  2825   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
  2826     return best;
  2828   return NULL;
  2831 void InstanceKlass::add_member_name(int index, Handle mem_name) {
  2832   jweak mem_name_wref = JNIHandles::make_weak_global(mem_name);
  2833   MutexLocker ml(MemberNameTable_lock);
  2834   assert(0 <= index && index < idnum_allocated_count(), "index is out of bounds");
  2835   DEBUG_ONLY(No_Safepoint_Verifier nsv);
  2837   if (_member_names == NULL) {
  2838     _member_names = new (ResourceObj::C_HEAP, mtClass) MemberNameTable(idnum_allocated_count());
  2840   _member_names->add_member_name(index, mem_name_wref);
  2843 oop InstanceKlass::get_member_name(int index) {
  2844   MutexLocker ml(MemberNameTable_lock);
  2845   assert(0 <= index && index < idnum_allocated_count(), "index is out of bounds");
  2846   DEBUG_ONLY(No_Safepoint_Verifier nsv);
  2848   if (_member_names == NULL) {
  2849     return NULL;
  2851   oop mem_name =_member_names->get_member_name(index);
  2852   return mem_name;
  2855 // -----------------------------------------------------------------------------------------------------
  2856 // Printing
  2858 #ifndef PRODUCT
  2860 #define BULLET  " - "
  2862 static const char* state_names[] = {
  2863   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
  2864 };
  2866 static void print_vtable(intptr_t* start, int len, outputStream* st) {
  2867   for (int i = 0; i < len; i++) {
  2868     intptr_t e = start[i];
  2869     st->print("%d : " INTPTR_FORMAT, i, e);
  2870     if (e != 0 && ((Metadata*)e)->is_metaspace_object()) {
  2871       st->print(" ");
  2872       ((Metadata*)e)->print_value_on(st);
  2874     st->cr();
  2878 void InstanceKlass::print_on(outputStream* st) const {
  2879   assert(is_klass(), "must be klass");
  2880   Klass::print_on(st);
  2882   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
  2883   st->print(BULLET"klass size:        %d", size());                               st->cr();
  2884   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
  2885   st->print(BULLET"state:             "); st->print_cr(state_names[_init_state]);
  2886   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
  2887   st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
  2888   st->print(BULLET"sub:               ");
  2889   Klass* sub = subklass();
  2890   int n;
  2891   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
  2892     if (n < MaxSubklassPrintSize) {
  2893       sub->print_value_on(st);
  2894       st->print("   ");
  2897   if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
  2898   st->cr();
  2900   if (is_interface()) {
  2901     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
  2902     if (nof_implementors() == 1) {
  2903       st->print_cr(BULLET"implementor:    ");
  2904       st->print("   ");
  2905       implementor()->print_value_on(st);
  2906       st->cr();
  2910   st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
  2911   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
  2912   if (Verbose || WizardMode) {
  2913     Array<Method*>* method_array = methods();
  2914     for (int i = 0; i < method_array->length(); i++) {
  2915       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
  2918   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);      st->cr();
  2919   st->print(BULLET"default_methods:   "); default_methods()->print_value_on(st);      st->cr();
  2920   if (Verbose && default_methods() != NULL) {
  2921     Array<Method*>* method_array = default_methods();
  2922     for (int i = 0; i < method_array->length(); i++) {
  2923       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
  2926   if (default_vtable_indices() != NULL) {
  2927     st->print(BULLET"default vtable indices:   "); default_vtable_indices()->print_value_on(st);       st->cr();
  2929   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
  2930   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
  2931   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
  2932   if (class_loader_data() != NULL) {
  2933     st->print(BULLET"class loader data:  ");
  2934     class_loader_data()->print_value_on(st);
  2935     st->cr();
  2937   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
  2938   if (source_file_name() != NULL) {
  2939     st->print(BULLET"source file:       ");
  2940     source_file_name()->print_value_on(st);
  2941     st->cr();
  2943   if (source_debug_extension() != NULL) {
  2944     st->print(BULLET"source debug extension:       ");
  2945     st->print("%s", source_debug_extension());
  2946     st->cr();
  2948   st->print(BULLET"class annotations:       "); class_annotations()->print_value_on(st); st->cr();
  2949   st->print(BULLET"class type annotations:  "); class_type_annotations()->print_value_on(st); st->cr();
  2950   st->print(BULLET"field annotations:       "); fields_annotations()->print_value_on(st); st->cr();
  2951   st->print(BULLET"field type annotations:  "); fields_type_annotations()->print_value_on(st); st->cr();
  2953     bool have_pv = false;
  2954     PreviousVersionWalker pvw(Thread::current(), (InstanceKlass*)this);
  2955     for (PreviousVersionNode * pv_node = pvw.next_previous_version();
  2956          pv_node != NULL; pv_node = pvw.next_previous_version()) {
  2957       if (!have_pv)
  2958         st->print(BULLET"previous version:  ");
  2959       have_pv = true;
  2960       pv_node->prev_constant_pool()->print_value_on(st);
  2962     if (have_pv) st->cr();
  2963   } // pvw is cleaned up
  2965   if (generic_signature() != NULL) {
  2966     st->print(BULLET"generic signature: ");
  2967     generic_signature()->print_value_on(st);
  2968     st->cr();
  2970   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
  2971   st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
  2972   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable());  st->cr();
  2973   if (vtable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_vtable(), vtable_length(), st);
  2974   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
  2975   if (itable_length() > 0 && (Verbose || WizardMode))  print_vtable(start_of_itable(), itable_length(), st);
  2976   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
  2977   FieldPrinter print_static_field(st);
  2978   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
  2979   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
  2980   FieldPrinter print_nonstatic_field(st);
  2981   ((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);
  2983   st->print(BULLET"non-static oop maps: ");
  2984   OopMapBlock* map     = start_of_nonstatic_oop_maps();
  2985   OopMapBlock* end_map = map + nonstatic_oop_map_count();
  2986   while (map < end_map) {
  2987     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
  2988     map++;
  2990   st->cr();
  2993 #endif //PRODUCT
  2995 void InstanceKlass::print_value_on(outputStream* st) const {
  2996   assert(is_klass(), "must be klass");
  2997   if (Verbose || WizardMode)  access_flags().print_on(st);
  2998   name()->print_value_on(st);
  3001 #ifndef PRODUCT
  3003 void FieldPrinter::do_field(fieldDescriptor* fd) {
  3004   _st->print(BULLET);
  3005    if (_obj == NULL) {
  3006      fd->print_on(_st);
  3007      _st->cr();
  3008    } else {
  3009      fd->print_on_for(_st, _obj);
  3010      _st->cr();
  3015 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
  3016   Klass::oop_print_on(obj, st);
  3018   if (this == SystemDictionary::String_klass()) {
  3019     typeArrayOop value  = java_lang_String::value(obj);
  3020     juint        offset = java_lang_String::offset(obj);
  3021     juint        length = java_lang_String::length(obj);
  3022     if (value != NULL &&
  3023         value->is_typeArray() &&
  3024         offset          <= (juint) value->length() &&
  3025         offset + length <= (juint) value->length()) {
  3026       st->print(BULLET"string: ");
  3027       Handle h_obj(obj);
  3028       java_lang_String::print(h_obj, st);
  3029       st->cr();
  3030       if (!WizardMode)  return;  // that is enough
  3034   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
  3035   FieldPrinter print_field(st, obj);
  3036   do_nonstatic_fields(&print_field);
  3038   if (this == SystemDictionary::Class_klass()) {
  3039     st->print(BULLET"signature: ");
  3040     java_lang_Class::print_signature(obj, st);
  3041     st->cr();
  3042     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
  3043     st->print(BULLET"fake entry for mirror: ");
  3044     mirrored_klass->print_value_on_maybe_null(st);
  3045     st->cr();
  3046     Klass* array_klass = java_lang_Class::array_klass(obj);
  3047     st->print(BULLET"fake entry for array: ");
  3048     array_klass->print_value_on_maybe_null(st);
  3049     st->cr();
  3050     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
  3051     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
  3052     Klass* real_klass = java_lang_Class::as_Klass(obj);
  3053     if (real_klass != NULL && real_klass->oop_is_instance()) {
  3054       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
  3056   } else if (this == SystemDictionary::MethodType_klass()) {
  3057     st->print(BULLET"signature: ");
  3058     java_lang_invoke_MethodType::print_signature(obj, st);
  3059     st->cr();
  3063 #endif //PRODUCT
  3065 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
  3066   st->print("a ");
  3067   name()->print_value_on(st);
  3068   obj->print_address_on(st);
  3069   if (this == SystemDictionary::String_klass()
  3070       && java_lang_String::value(obj) != NULL) {
  3071     ResourceMark rm;
  3072     int len = java_lang_String::length(obj);
  3073     int plen = (len < 24 ? len : 12);
  3074     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
  3075     st->print(" = \"%s\"", str);
  3076     if (len > plen)
  3077       st->print("...[%d]", len);
  3078   } else if (this == SystemDictionary::Class_klass()) {
  3079     Klass* k = java_lang_Class::as_Klass(obj);
  3080     st->print(" = ");
  3081     if (k != NULL) {
  3082       k->print_value_on(st);
  3083     } else {
  3084       const char* tname = type2name(java_lang_Class::primitive_type(obj));
  3085       st->print("%s", tname ? tname : "type?");
  3087   } else if (this == SystemDictionary::MethodType_klass()) {
  3088     st->print(" = ");
  3089     java_lang_invoke_MethodType::print_signature(obj, st);
  3090   } else if (java_lang_boxing_object::is_instance(obj)) {
  3091     st->print(" = ");
  3092     java_lang_boxing_object::print(obj, st);
  3093   } else if (this == SystemDictionary::LambdaForm_klass()) {
  3094     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
  3095     if (vmentry != NULL) {
  3096       st->print(" => ");
  3097       vmentry->print_value_on(st);
  3099   } else if (this == SystemDictionary::MemberName_klass()) {
  3100     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
  3101     if (vmtarget != NULL) {
  3102       st->print(" = ");
  3103       vmtarget->print_value_on(st);
  3104     } else {
  3105       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
  3106       st->print(".");
  3107       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
  3112 const char* InstanceKlass::internal_name() const {
  3113   return external_name();
  3116 #if INCLUDE_SERVICES
  3117 // Size Statistics
  3118 void InstanceKlass::collect_statistics(KlassSizeStats *sz) const {
  3119   Klass::collect_statistics(sz);
  3121   sz->_inst_size  = HeapWordSize * size_helper();
  3122   sz->_vtab_bytes = HeapWordSize * align_object_offset(vtable_length());
  3123   sz->_itab_bytes = HeapWordSize * align_object_offset(itable_length());
  3124   sz->_nonstatic_oopmap_bytes = HeapWordSize *
  3125         ((is_interface() || is_anonymous()) ?
  3126          align_object_offset(nonstatic_oop_map_size()) :
  3127          nonstatic_oop_map_size());
  3129   int n = 0;
  3130   n += (sz->_methods_array_bytes         = sz->count_array(methods()));
  3131   n += (sz->_method_ordering_bytes       = sz->count_array(method_ordering()));
  3132   n += (sz->_local_interfaces_bytes      = sz->count_array(local_interfaces()));
  3133   n += (sz->_transitive_interfaces_bytes = sz->count_array(transitive_interfaces()));
  3134   n += (sz->_fields_bytes                = sz->count_array(fields()));
  3135   n += (sz->_inner_classes_bytes         = sz->count_array(inner_classes()));
  3136   sz->_ro_bytes += n;
  3138   const ConstantPool* cp = constants();
  3139   if (cp) {
  3140     cp->collect_statistics(sz);
  3143   const Annotations* anno = annotations();
  3144   if (anno) {
  3145     anno->collect_statistics(sz);
  3148   const Array<Method*>* methods_array = methods();
  3149   if (methods()) {
  3150     for (int i = 0; i < methods_array->length(); i++) {
  3151       Method* method = methods_array->at(i);
  3152       if (method) {
  3153         sz->_method_count ++;
  3154         method->collect_statistics(sz);
  3159 #endif // INCLUDE_SERVICES
  3161 // Verification
  3163 class VerifyFieldClosure: public OopClosure {
  3164  protected:
  3165   template <class T> void do_oop_work(T* p) {
  3166     oop obj = oopDesc::load_decode_heap_oop(p);
  3167     if (!obj->is_oop_or_null()) {
  3168       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
  3169       Universe::print();
  3170       guarantee(false, "boom");
  3173  public:
  3174   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
  3175   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
  3176 };
  3178 void InstanceKlass::verify_on(outputStream* st) {
  3179 #ifndef PRODUCT
  3180   // Avoid redundant verifies, this really should be in product.
  3181   if (_verify_count == Universe::verify_count()) return;
  3182   _verify_count = Universe::verify_count();
  3183 #endif
  3185   // Verify Klass
  3186   Klass::verify_on(st);
  3188   // Verify that klass is present in ClassLoaderData
  3189   guarantee(class_loader_data()->contains_klass(this),
  3190             "this class isn't found in class loader data");
  3192   // Verify vtables
  3193   if (is_linked()) {
  3194     ResourceMark rm;
  3195     // $$$ This used to be done only for m/s collections.  Doing it
  3196     // always seemed a valid generalization.  (DLD -- 6/00)
  3197     vtable()->verify(st);
  3200   // Verify first subklass
  3201   if (subklass_oop() != NULL) {
  3202     guarantee(subklass_oop()->is_klass(), "should be klass");
  3205   // Verify siblings
  3206   Klass* super = this->super();
  3207   Klass* sib = next_sibling();
  3208   if (sib != NULL) {
  3209     if (sib == this) {
  3210       fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
  3213     guarantee(sib->is_klass(), "should be klass");
  3214     guarantee(sib->super() == super, "siblings should have same superklass");
  3217   // Verify implementor fields
  3218   Klass* im = implementor();
  3219   if (im != NULL) {
  3220     guarantee(is_interface(), "only interfaces should have implementor set");
  3221     guarantee(im->is_klass(), "should be klass");
  3222     guarantee(!im->is_interface() || im == this,
  3223       "implementors cannot be interfaces");
  3226   // Verify local interfaces
  3227   if (local_interfaces()) {
  3228     Array<Klass*>* local_interfaces = this->local_interfaces();
  3229     for (int j = 0; j < local_interfaces->length(); j++) {
  3230       Klass* e = local_interfaces->at(j);
  3231       guarantee(e->is_klass() && e->is_interface(), "invalid local interface");
  3235   // Verify transitive interfaces
  3236   if (transitive_interfaces() != NULL) {
  3237     Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
  3238     for (int j = 0; j < transitive_interfaces->length(); j++) {
  3239       Klass* e = transitive_interfaces->at(j);
  3240       guarantee(e->is_klass() && e->is_interface(), "invalid transitive interface");
  3244   // Verify methods
  3245   if (methods() != NULL) {
  3246     Array<Method*>* methods = this->methods();
  3247     for (int j = 0; j < methods->length(); j++) {
  3248       guarantee(methods->at(j)->is_method(), "non-method in methods array");
  3250     for (int j = 0; j < methods->length() - 1; j++) {
  3251       Method* m1 = methods->at(j);
  3252       Method* m2 = methods->at(j + 1);
  3253       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
  3257   // Verify method ordering
  3258   if (method_ordering() != NULL) {
  3259     Array<int>* method_ordering = this->method_ordering();
  3260     int length = method_ordering->length();
  3261     if (JvmtiExport::can_maintain_original_method_order() ||
  3262         ((UseSharedSpaces || DumpSharedSpaces) && length != 0)) {
  3263       guarantee(length == methods()->length(), "invalid method ordering length");
  3264       jlong sum = 0;
  3265       for (int j = 0; j < length; j++) {
  3266         int original_index = method_ordering->at(j);
  3267         guarantee(original_index >= 0, "invalid method ordering index");
  3268         guarantee(original_index < length, "invalid method ordering index");
  3269         sum += original_index;
  3271       // Verify sum of indices 0,1,...,length-1
  3272       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
  3273     } else {
  3274       guarantee(length == 0, "invalid method ordering length");
  3278   // Verify default methods
  3279   if (default_methods() != NULL) {
  3280     Array<Method*>* methods = this->default_methods();
  3281     for (int j = 0; j < methods->length(); j++) {
  3282       guarantee(methods->at(j)->is_method(), "non-method in methods array");
  3284     for (int j = 0; j < methods->length() - 1; j++) {
  3285       Method* m1 = methods->at(j);
  3286       Method* m2 = methods->at(j + 1);
  3287       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
  3291   // Verify JNI static field identifiers
  3292   if (jni_ids() != NULL) {
  3293     jni_ids()->verify(this);
  3296   // Verify other fields
  3297   if (array_klasses() != NULL) {
  3298     guarantee(array_klasses()->is_klass(), "should be klass");
  3300   if (constants() != NULL) {
  3301     guarantee(constants()->is_constantPool(), "should be constant pool");
  3303   const Klass* host = host_klass();
  3304   if (host != NULL) {
  3305     guarantee(host->is_klass(), "should be klass");
  3309 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
  3310   Klass::oop_verify_on(obj, st);
  3311   VerifyFieldClosure blk;
  3312   obj->oop_iterate_no_header(&blk);
  3316 // JNIid class for jfieldIDs only
  3317 // Note to reviewers:
  3318 // These JNI functions are just moved over to column 1 and not changed
  3319 // in the compressed oops workspace.
  3320 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
  3321   _holder = holder;
  3322   _offset = offset;
  3323   _next = next;
  3324   debug_only(_is_static_field_id = false;)
  3328 JNIid* JNIid::find(int offset) {
  3329   JNIid* current = this;
  3330   while (current != NULL) {
  3331     if (current->offset() == offset) return current;
  3332     current = current->next();
  3334   return NULL;
  3337 void JNIid::deallocate(JNIid* current) {
  3338   while (current != NULL) {
  3339     JNIid* next = current->next();
  3340     delete current;
  3341     current = next;
  3346 void JNIid::verify(Klass* holder) {
  3347   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
  3348   int end_field_offset;
  3349   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
  3351   JNIid* current = this;
  3352   while (current != NULL) {
  3353     guarantee(current->holder() == holder, "Invalid klass in JNIid");
  3354 #ifdef ASSERT
  3355     int o = current->offset();
  3356     if (current->is_static_field_id()) {
  3357       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
  3359 #endif
  3360     current = current->next();
  3365 #ifdef ASSERT
  3366 void InstanceKlass::set_init_state(ClassState state) {
  3367   bool good_state = is_shared() ? (_init_state <= state)
  3368                                                : (_init_state < state);
  3369   assert(good_state || state == allocated, "illegal state transition");
  3370   _init_state = (u1)state;
  3372 #endif
  3375 // RedefineClasses() support for previous versions:
  3377 // Purge previous versions
  3378 static void purge_previous_versions_internal(InstanceKlass* ik, int emcp_method_count) {
  3379   if (ik->previous_versions() != NULL) {
  3380     // This klass has previous versions so see what we can cleanup
  3381     // while it is safe to do so.
  3383     int deleted_count = 0;    // leave debugging breadcrumbs
  3384     int live_count = 0;
  3385     ClassLoaderData* loader_data = ik->class_loader_data() == NULL ?
  3386                        ClassLoaderData::the_null_class_loader_data() :
  3387                        ik->class_loader_data();
  3389     // RC_TRACE macro has an embedded ResourceMark
  3390     RC_TRACE(0x00000200, ("purge: %s: previous version length=%d",
  3391       ik->external_name(), ik->previous_versions()->length()));
  3393     for (int i = ik->previous_versions()->length() - 1; i >= 0; i--) {
  3394       // check the previous versions array
  3395       PreviousVersionNode * pv_node = ik->previous_versions()->at(i);
  3396       ConstantPool* cp_ref = pv_node->prev_constant_pool();
  3397       assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
  3399       ConstantPool* pvcp = cp_ref;
  3400       if (!pvcp->on_stack()) {
  3401         // If the constant pool isn't on stack, none of the methods
  3402         // are executing.  Delete all the methods, the constant pool and
  3403         // and this previous version node.
  3404         GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3405         if (method_refs != NULL) {
  3406           for (int j = method_refs->length() - 1; j >= 0; j--) {
  3407             Method* method = method_refs->at(j);
  3408             assert(method != NULL, "method ref was unexpectedly cleared");
  3409             method_refs->remove_at(j);
  3410             // method will be freed with associated class.
  3413         // Remove the constant pool
  3414         delete pv_node;
  3415         // Since we are traversing the array backwards, we don't have to
  3416         // do anything special with the index.
  3417         ik->previous_versions()->remove_at(i);
  3418         deleted_count++;
  3419         continue;
  3420       } else {
  3421         RC_TRACE(0x00000200, ("purge: previous version @%d is alive", i));
  3422         assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
  3423         guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
  3424         live_count++;
  3427       // At least one method is live in this previous version, clean out
  3428       // the others or mark them as obsolete.
  3429       GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3430       if (method_refs != NULL) {
  3431         RC_TRACE(0x00000200, ("purge: previous methods length=%d",
  3432           method_refs->length()));
  3433         for (int j = method_refs->length() - 1; j >= 0; j--) {
  3434           Method* method = method_refs->at(j);
  3435           assert(method != NULL, "method ref was unexpectedly cleared");
  3437           // Remove the emcp method if it's not executing
  3438           // If it's been made obsolete by a redefinition of a non-emcp
  3439           // method, mark it as obsolete but leave it to clean up later.
  3440           if (!method->on_stack()) {
  3441             method_refs->remove_at(j);
  3442           } else if (emcp_method_count == 0) {
  3443             method->set_is_obsolete();
  3444           } else {
  3445             // RC_TRACE macro has an embedded ResourceMark
  3446             RC_TRACE(0x00000200,
  3447               ("purge: %s(%s): prev method @%d in version @%d is alive",
  3448               method->name()->as_C_string(),
  3449               method->signature()->as_C_string(), j, i));
  3454     assert(ik->previous_versions()->length() == live_count, "sanity check");
  3455     RC_TRACE(0x00000200,
  3456       ("purge: previous version stats: live=%d, deleted=%d", live_count,
  3457       deleted_count));
  3461 // External interface for use during class unloading.
  3462 void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
  3463   // Call with >0 emcp methods since they are not currently being redefined.
  3464   purge_previous_versions_internal(ik, 1);
  3468 // Potentially add an information node that contains pointers to the
  3469 // interesting parts of the previous version of the_class.
  3470 // This is also where we clean out any unused references.
  3471 // Note that while we delete nodes from the _previous_versions
  3472 // array, we never delete the array itself until the klass is
  3473 // unloaded. The has_been_redefined() query depends on that fact.
  3474 //
  3475 void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
  3476        BitMap* emcp_methods, int emcp_method_count) {
  3477   assert(Thread::current()->is_VM_thread(),
  3478          "only VMThread can add previous versions");
  3480   if (_previous_versions == NULL) {
  3481     // This is the first previous version so make some space.
  3482     // Start with 2 elements under the assumption that the class
  3483     // won't be redefined much.
  3484     _previous_versions =  new (ResourceObj::C_HEAP, mtClass)
  3485                             GrowableArray<PreviousVersionNode *>(2, true);
  3488   ConstantPool* cp_ref = ikh->constants();
  3490   // RC_TRACE macro has an embedded ResourceMark
  3491   RC_TRACE(0x00000400, ("adding previous version ref for %s @%d, EMCP_cnt=%d "
  3492                         "on_stack=%d",
  3493     ikh->external_name(), _previous_versions->length(), emcp_method_count,
  3494     cp_ref->on_stack()));
  3496   // If the constant pool for this previous version of the class
  3497   // is not marked as being on the stack, then none of the methods
  3498   // in this previous version of the class are on the stack so
  3499   // we don't need to create a new PreviousVersionNode. However,
  3500   // we still need to examine older previous versions below.
  3501   Array<Method*>* old_methods = ikh->methods();
  3503   if (cp_ref->on_stack()) {
  3504     PreviousVersionNode * pv_node = NULL;
  3505     if (emcp_method_count == 0) {
  3506       // non-shared ConstantPool gets a reference
  3507       pv_node = new PreviousVersionNode(cp_ref, NULL);
  3508       RC_TRACE(0x00000400,
  3509           ("add: all methods are obsolete; flushing any EMCP refs"));
  3510     } else {
  3511       int local_count = 0;
  3512       GrowableArray<Method*>* method_refs = new (ResourceObj::C_HEAP, mtClass)
  3513           GrowableArray<Method*>(emcp_method_count, true);
  3514       for (int i = 0; i < old_methods->length(); i++) {
  3515         if (emcp_methods->at(i)) {
  3516             // this old method is EMCP. Save it only if it's on the stack
  3517             Method* old_method = old_methods->at(i);
  3518             if (old_method->on_stack()) {
  3519               method_refs->append(old_method);
  3521           if (++local_count >= emcp_method_count) {
  3522             // no more EMCP methods so bail out now
  3523             break;
  3527       // non-shared ConstantPool gets a reference
  3528       pv_node = new PreviousVersionNode(cp_ref, method_refs);
  3530     // append new previous version.
  3531     _previous_versions->append(pv_node);
  3534   // Since the caller is the VMThread and we are at a safepoint, this
  3535   // is a good time to clear out unused references.
  3537   RC_TRACE(0x00000400, ("add: previous version length=%d",
  3538     _previous_versions->length()));
  3540   // Purge previous versions not executing on the stack
  3541   purge_previous_versions_internal(this, emcp_method_count);
  3543   int obsolete_method_count = old_methods->length() - emcp_method_count;
  3545   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
  3546       _previous_versions->length() > 0) {
  3547     // We have a mix of obsolete and EMCP methods so we have to
  3548     // clear out any matching EMCP method entries the hard way.
  3549     int local_count = 0;
  3550     for (int i = 0; i < old_methods->length(); i++) {
  3551       if (!emcp_methods->at(i)) {
  3552         // only obsolete methods are interesting
  3553         Method* old_method = old_methods->at(i);
  3554         Symbol* m_name = old_method->name();
  3555         Symbol* m_signature = old_method->signature();
  3557         // we might not have added the last entry
  3558         for (int j = _previous_versions->length() - 1; j >= 0; j--) {
  3559           // check the previous versions array for non executing obsolete methods
  3560           PreviousVersionNode * pv_node = _previous_versions->at(j);
  3562           GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3563           if (method_refs == NULL) {
  3564             // We have run into a PreviousVersion generation where
  3565             // all methods were made obsolete during that generation's
  3566             // RedefineClasses() operation. At the time of that
  3567             // operation, all EMCP methods were flushed so we don't
  3568             // have to go back any further.
  3569             //
  3570             // A NULL method_refs is different than an empty method_refs.
  3571             // We cannot infer any optimizations about older generations
  3572             // from an empty method_refs for the current generation.
  3573             break;
  3576           for (int k = method_refs->length() - 1; k >= 0; k--) {
  3577             Method* method = method_refs->at(k);
  3579             if (!method->is_obsolete() &&
  3580                 method->name() == m_name &&
  3581                 method->signature() == m_signature) {
  3582               // The current RedefineClasses() call has made all EMCP
  3583               // versions of this method obsolete so mark it as obsolete
  3584               // and remove the reference.
  3585               RC_TRACE(0x00000400,
  3586                 ("add: %s(%s): flush obsolete method @%d in version @%d",
  3587                 m_name->as_C_string(), m_signature->as_C_string(), k, j));
  3589               method->set_is_obsolete();
  3590               // Leave obsolete methods on the previous version list to
  3591               // clean up later.
  3592               break;
  3596           // The previous loop may not find a matching EMCP method, but
  3597           // that doesn't mean that we can optimize and not go any
  3598           // further back in the PreviousVersion generations. The EMCP
  3599           // method for this generation could have already been deleted,
  3600           // but there still may be an older EMCP method that has not
  3601           // been deleted.
  3604         if (++local_count >= obsolete_method_count) {
  3605           // no more obsolete methods so bail out now
  3606           break;
  3611 } // end add_previous_version()
  3614 // Determine if InstanceKlass has a previous version.
  3615 bool InstanceKlass::has_previous_version() const {
  3616   return (_previous_versions != NULL && _previous_versions->length() > 0);
  3617 } // end has_previous_version()
  3620 Method* InstanceKlass::method_with_idnum(int idnum) {
  3621   Method* m = NULL;
  3622   if (idnum < methods()->length()) {
  3623     m = methods()->at(idnum);
  3625   if (m == NULL || m->method_idnum() != idnum) {
  3626     for (int index = 0; index < methods()->length(); ++index) {
  3627       m = methods()->at(index);
  3628       if (m->method_idnum() == idnum) {
  3629         return m;
  3632     // None found, return null for the caller to handle.
  3633     return NULL;
  3635   return m;
  3638 jint InstanceKlass::get_cached_class_file_len() {
  3639   return VM_RedefineClasses::get_cached_class_file_len(_cached_class_file);
  3642 unsigned char * InstanceKlass::get_cached_class_file_bytes() {
  3643   return VM_RedefineClasses::get_cached_class_file_bytes(_cached_class_file);
  3647 // Construct a PreviousVersionNode entry for the array hung off
  3648 // the InstanceKlass.
  3649 PreviousVersionNode::PreviousVersionNode(ConstantPool* prev_constant_pool,
  3650   GrowableArray<Method*>* prev_EMCP_methods) {
  3652   _prev_constant_pool = prev_constant_pool;
  3653   _prev_EMCP_methods = prev_EMCP_methods;
  3657 // Destroy a PreviousVersionNode
  3658 PreviousVersionNode::~PreviousVersionNode() {
  3659   if (_prev_constant_pool != NULL) {
  3660     _prev_constant_pool = NULL;
  3663   if (_prev_EMCP_methods != NULL) {
  3664     delete _prev_EMCP_methods;
  3668 // Construct a helper for walking the previous versions array
  3669 PreviousVersionWalker::PreviousVersionWalker(Thread* thread, InstanceKlass *ik) {
  3670   _thread = thread;
  3671   _previous_versions = ik->previous_versions();
  3672   _current_index = 0;
  3673   _current_p = NULL;
  3674   _current_constant_pool_handle = constantPoolHandle(thread, ik->constants());
  3678 // Return the interesting information for the next previous version
  3679 // of the klass. Returns NULL if there are no more previous versions.
  3680 PreviousVersionNode* PreviousVersionWalker::next_previous_version() {
  3681   if (_previous_versions == NULL) {
  3682     // no previous versions so nothing to return
  3683     return NULL;
  3686   _current_p = NULL;  // reset to NULL
  3687   _current_constant_pool_handle = NULL;
  3689   int length = _previous_versions->length();
  3691   while (_current_index < length) {
  3692     PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
  3694     // Save a handle to the constant pool for this previous version,
  3695     // which keeps all the methods from being deallocated.
  3696     _current_constant_pool_handle = constantPoolHandle(_thread, pv_node->prev_constant_pool());
  3697     _current_p = pv_node;
  3698     return pv_node;
  3701   return NULL;
  3702 } // end next_previous_version()

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