src/share/vm/oops/instanceKlass.cpp

Thu, 11 Oct 2012 12:25:42 -0400

author
kamg
date
Thu, 11 Oct 2012 12:25:42 -0400
changeset 4245
4735d2c84362
parent 4142
d8ce2825b193
child 4267
bd7a7ce2e264
child 4278
070d523b96a7
permissions
-rw-r--r--

7200776: Implement default methods in interfaces
Summary: Add generic type analysis and default method selection algorithms
Reviewed-by: coleenp, acorn

     1 /*
     2  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "classfile/javaClasses.hpp"
    27 #include "classfile/systemDictionary.hpp"
    28 #include "classfile/verifier.hpp"
    29 #include "classfile/vmSymbols.hpp"
    30 #include "compiler/compileBroker.hpp"
    31 #include "gc_implementation/shared/markSweep.inline.hpp"
    32 #include "gc_interface/collectedHeap.inline.hpp"
    33 #include "interpreter/oopMapCache.hpp"
    34 #include "interpreter/rewriter.hpp"
    35 #include "jvmtifiles/jvmti.h"
    36 #include "memory/genOopClosures.inline.hpp"
    37 #include "memory/metadataFactory.hpp"
    38 #include "memory/oopFactory.hpp"
    39 #include "oops/fieldStreams.hpp"
    40 #include "oops/instanceClassLoaderKlass.hpp"
    41 #include "oops/instanceKlass.hpp"
    42 #include "oops/instanceMirrorKlass.hpp"
    43 #include "oops/instanceOop.hpp"
    44 #include "oops/klass.inline.hpp"
    45 #include "oops/method.hpp"
    46 #include "oops/oop.inline.hpp"
    47 #include "oops/symbol.hpp"
    48 #include "prims/jvmtiExport.hpp"
    49 #include "prims/jvmtiRedefineClassesTrace.hpp"
    50 #include "runtime/fieldDescriptor.hpp"
    51 #include "runtime/handles.inline.hpp"
    52 #include "runtime/javaCalls.hpp"
    53 #include "runtime/mutexLocker.hpp"
    54 #include "services/threadService.hpp"
    55 #include "utilities/dtrace.hpp"
    56 #ifdef TARGET_OS_FAMILY_linux
    57 # include "thread_linux.inline.hpp"
    58 #endif
    59 #ifdef TARGET_OS_FAMILY_solaris
    60 # include "thread_solaris.inline.hpp"
    61 #endif
    62 #ifdef TARGET_OS_FAMILY_windows
    63 # include "thread_windows.inline.hpp"
    64 #endif
    65 #ifdef TARGET_OS_FAMILY_bsd
    66 # include "thread_bsd.inline.hpp"
    67 #endif
    68 #ifndef SERIALGC
    69 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp"
    70 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
    71 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
    72 #include "gc_implementation/g1/g1RemSet.inline.hpp"
    73 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
    74 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
    75 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.inline.hpp"
    76 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
    77 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
    78 #include "oops/oop.pcgc.inline.hpp"
    79 #endif
    80 #ifdef COMPILER1
    81 #include "c1/c1_Compiler.hpp"
    82 #endif
    84 #ifdef DTRACE_ENABLED
    86 #ifndef USDT2
    88 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
    89   char*, intptr_t, oop, intptr_t);
    90 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
    91   char*, intptr_t, oop, intptr_t, int);
    92 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
    93   char*, intptr_t, oop, intptr_t, int);
    94 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
    95   char*, intptr_t, oop, intptr_t, int);
    96 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
    97   char*, intptr_t, oop, intptr_t, int);
    98 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
    99   char*, intptr_t, oop, intptr_t, int);
   100 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
   101   char*, intptr_t, oop, intptr_t, int);
   102 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
   103   char*, intptr_t, oop, intptr_t, int);
   105 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
   106   {                                                              \
   107     char* data = NULL;                                           \
   108     int len = 0;                                                 \
   109     Symbol* name = (clss)->name();                               \
   110     if (name != NULL) {                                          \
   111       data = (char*)name->bytes();                               \
   112       len = name->utf8_length();                                 \
   113     }                                                            \
   114     HS_DTRACE_PROBE4(hotspot, class__initialization__##type,     \
   115       data, len, (clss)->class_loader(), thread_type);           \
   116   }
   118 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
   119   {                                                              \
   120     char* data = NULL;                                           \
   121     int len = 0;                                                 \
   122     Symbol* name = (clss)->name();                               \
   123     if (name != NULL) {                                          \
   124       data = (char*)name->bytes();                               \
   125       len = name->utf8_length();                                 \
   126     }                                                            \
   127     HS_DTRACE_PROBE5(hotspot, class__initialization__##type,     \
   128       data, len, (clss)->class_loader(), thread_type, wait);     \
   129   }
   130 #else /* USDT2 */
   132 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
   133 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
   134 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
   135 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
   136 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
   137 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
   138 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
   139 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
   140 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
   141   {                                                              \
   142     char* data = NULL;                                           \
   143     int len = 0;                                                 \
   144     Symbol* name = (clss)->name();                               \
   145     if (name != NULL) {                                          \
   146       data = (char*)name->bytes();                               \
   147       len = name->utf8_length();                                 \
   148     }                                                            \
   149     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
   150       data, len, (clss)->class_loader(), thread_type);           \
   151   }
   153 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
   154   {                                                              \
   155     char* data = NULL;                                           \
   156     int len = 0;                                                 \
   157     Symbol* name = (clss)->name();                               \
   158     if (name != NULL) {                                          \
   159       data = (char*)name->bytes();                               \
   160       len = name->utf8_length();                                 \
   161     }                                                            \
   162     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
   163       data, len, (clss)->class_loader(), thread_type, wait);     \
   164   }
   165 #endif /* USDT2 */
   167 #else //  ndef DTRACE_ENABLED
   169 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
   170 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
   172 #endif //  ndef DTRACE_ENABLED
   174 Klass* InstanceKlass::allocate_instance_klass(ClassLoaderData* loader_data,
   175                                                 int vtable_len,
   176                                                 int itable_len,
   177                                                 int static_field_size,
   178                                                 int nonstatic_oop_map_size,
   179                                                 ReferenceType rt,
   180                                                 AccessFlags access_flags,
   181                                                 Symbol* name,
   182                                               Klass* super_klass,
   183                                                 KlassHandle host_klass,
   184                                                 TRAPS) {
   186   int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
   187                                  access_flags.is_interface(),
   188                                  !host_klass.is_null());
   190   // Allocation
   191   InstanceKlass* ik;
   192   if (rt == REF_NONE) {
   193     if (name == vmSymbols::java_lang_Class()) {
   194       ik = new (loader_data, size, THREAD) InstanceMirrorKlass(
   195         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   196         access_flags, !host_klass.is_null());
   197     } else if (name == vmSymbols::java_lang_ClassLoader() ||
   198           (SystemDictionary::ClassLoader_klass_loaded() &&
   199           super_klass != NULL &&
   200           super_klass->is_subtype_of(SystemDictionary::ClassLoader_klass()))) {
   201       ik = new (loader_data, size, THREAD) InstanceClassLoaderKlass(
   202         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   203         access_flags, !host_klass.is_null());
   204     } else {
   205       // normal class
   206       ik = new (loader_data, size, THREAD) InstanceKlass(
   207         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   208         access_flags, !host_klass.is_null());
   209     }
   210   } else {
   211     // reference klass
   212     ik = new (loader_data, size, THREAD) InstanceRefKlass(
   213         vtable_len, itable_len, static_field_size, nonstatic_oop_map_size, rt,
   214         access_flags, !host_klass.is_null());
   215   }
   217   return ik;
   218 }
   220 InstanceKlass::InstanceKlass(int vtable_len,
   221                              int itable_len,
   222                              int static_field_size,
   223                              int nonstatic_oop_map_size,
   224                              ReferenceType rt,
   225                              AccessFlags access_flags,
   226                              bool is_anonymous) {
   227   No_Safepoint_Verifier no_safepoint; // until k becomes parsable
   229   int size = InstanceKlass::size(vtable_len, itable_len, nonstatic_oop_map_size,
   230                                  access_flags.is_interface(), is_anonymous);
   232   // The sizes of these these three variables are used for determining the
   233   // size of the instanceKlassOop. It is critical that these are set to the right
   234   // sizes before the first GC, i.e., when we allocate the mirror.
   235   this->set_vtable_length(vtable_len);
   236   this->set_itable_length(itable_len);
   237   this->set_static_field_size(static_field_size);
   238   this->set_nonstatic_oop_map_size(nonstatic_oop_map_size);
   239   this->set_access_flags(access_flags);
   240   this->set_is_anonymous(is_anonymous);
   241   assert(this->size() == size, "wrong size for object");
   243   this->set_array_klasses(NULL);
   244   this->set_methods(NULL);
   245   this->set_method_ordering(NULL);
   246   this->set_local_interfaces(NULL);
   247   this->set_transitive_interfaces(NULL);
   248   this->init_implementor();
   249   this->set_fields(NULL, 0);
   250   this->set_constants(NULL);
   251   this->set_class_loader_data(NULL);
   252   this->set_protection_domain(NULL);
   253   this->set_signers(NULL);
   254   this->set_source_file_name(NULL);
   255   this->set_source_debug_extension(NULL, 0);
   256   this->set_array_name(NULL);
   257   this->set_inner_classes(NULL);
   258   this->set_static_oop_field_count(0);
   259   this->set_nonstatic_field_size(0);
   260   this->set_is_marked_dependent(false);
   261   this->set_init_state(InstanceKlass::allocated);
   262   this->set_init_thread(NULL);
   263   this->set_init_lock(NULL);
   264   this->set_reference_type(rt);
   265   this->set_oop_map_cache(NULL);
   266   this->set_jni_ids(NULL);
   267   this->set_osr_nmethods_head(NULL);
   268   this->set_breakpoints(NULL);
   269   this->init_previous_versions();
   270   this->set_generic_signature(NULL);
   271   this->release_set_methods_jmethod_ids(NULL);
   272   this->release_set_methods_cached_itable_indices(NULL);
   273   this->set_annotations(NULL);
   274   this->set_jvmti_cached_class_field_map(NULL);
   275   this->set_initial_method_idnum(0);
   277   // initialize the non-header words to zero
   278   intptr_t* p = (intptr_t*)this;
   279   for (int index = InstanceKlass::header_size(); index < size; index++) {
   280     p[index] = NULL_WORD;
   281   }
   283   // Set temporary value until parseClassFile updates it with the real instance
   284   // size.
   285   this->set_layout_helper(Klass::instance_layout_helper(0, true));
   286 }
   289 // This function deallocates the metadata and C heap pointers that the
   290 // InstanceKlass points to.
   291 void InstanceKlass::deallocate_contents(ClassLoaderData* loader_data) {
   293   // Orphan the mirror first, CMS thinks it's still live.
   294   java_lang_Class::set_klass(java_mirror(), NULL);
   296   // Need to take this class off the class loader data list.
   297   loader_data->remove_class(this);
   299   // The array_klass for this class is created later, after error handling.
   300   // For class redefinition, we keep the original class so this scratch class
   301   // doesn't have an array class.  Either way, assert that there is nothing
   302   // to deallocate.
   303   assert(array_klasses() == NULL, "array classes shouldn't be created for this class yet");
   305   // Release C heap allocated data that this might point to, which includes
   306   // reference counting symbol names.
   307   release_C_heap_structures();
   309   Array<Method*>* ms = methods();
   310   if (ms != Universe::the_empty_method_array()) {
   311     for (int i = 0; i <= methods()->length() -1 ; i++) {
   312       Method* method = methods()->at(i);
   313       // Only want to delete methods that are not executing for RedefineClasses.
   314       // The previous version will point to them so they're not totally dangling
   315       assert (!method->on_stack(), "shouldn't be called with methods on stack");
   316       MetadataFactory::free_metadata(loader_data, method);
   317     }
   318     MetadataFactory::free_array<Method*>(loader_data, methods());
   319   }
   320   set_methods(NULL);
   322   if (method_ordering() != Universe::the_empty_int_array()) {
   323     MetadataFactory::free_array<int>(loader_data, method_ordering());
   324   }
   325   set_method_ordering(NULL);
   327   // This array is in Klass, but remove it with the InstanceKlass since
   328   // this place would be the only caller and it can share memory with transitive
   329   // interfaces.
   330   if (secondary_supers() != Universe::the_empty_klass_array() &&
   331       secondary_supers() != transitive_interfaces()) {
   332     MetadataFactory::free_array<Klass*>(loader_data, secondary_supers());
   333   }
   334   set_secondary_supers(NULL);
   336   // Only deallocate transitive interfaces if not empty, same as super class
   337   // or same as local interfaces.   See code in parseClassFile.
   338   Array<Klass*>* ti = transitive_interfaces();
   339   if (ti != Universe::the_empty_klass_array() && ti != local_interfaces()) {
   340     // check that the interfaces don't come from super class
   341     Array<Klass*>* sti = (super() == NULL) ? NULL :
   342        InstanceKlass::cast(super())->transitive_interfaces();
   343     if (ti != sti) {
   344       MetadataFactory::free_array<Klass*>(loader_data, ti);
   345     }
   346   }
   347   set_transitive_interfaces(NULL);
   349   // local interfaces can be empty
   350   Array<Klass*>* li = local_interfaces();
   351   if (li != Universe::the_empty_klass_array()) {
   352     MetadataFactory::free_array<Klass*>(loader_data, li);
   353   }
   354   set_local_interfaces(NULL);
   356   MetadataFactory::free_array<jushort>(loader_data, fields());
   357   set_fields(NULL, 0);
   359   // If a method from a redefined class is using this constant pool, don't
   360   // delete it, yet.  The new class's previous version will point to this.
   361   assert (!constants()->on_stack(), "shouldn't be called if anything is onstack");
   362   MetadataFactory::free_metadata(loader_data, constants());
   363   set_constants(NULL);
   365   if (inner_classes() != Universe::the_empty_short_array()) {
   366     MetadataFactory::free_array<jushort>(loader_data, inner_classes());
   367   }
   368   set_inner_classes(NULL);
   370   // Null out Java heap objects, although these won't be walked to keep
   371   // alive once this InstanceKlass is deallocated.
   372   set_protection_domain(NULL);
   373   set_signers(NULL);
   374   set_init_lock(NULL);
   375   set_annotations(NULL);
   376 }
   378 volatile oop InstanceKlass::init_lock() const {
   379   volatile oop lock = _init_lock;  // read once
   380   assert((oop)lock != NULL || !is_not_initialized(), // initialized or in_error state
   381          "only fully initialized state can have a null lock");
   382   return lock;
   383 }
   385 // Set the initialization lock to null so the object can be GC'ed.  Any racing
   386 // threads to get this lock will see a null lock and will not lock.
   387 // That's okay because they all check for initialized state after getting
   388 // the lock and return.
   389 void InstanceKlass::fence_and_clear_init_lock() {
   390   // make sure previous stores are all done, notably the init_state.
   391   OrderAccess::storestore();
   392   klass_oop_store(&_init_lock, NULL);
   393   assert(!is_not_initialized(), "class must be initialized now");
   394 }
   397 bool InstanceKlass::should_be_initialized() const {
   398   return !is_initialized();
   399 }
   401 klassVtable* InstanceKlass::vtable() const {
   402   return new klassVtable(this, start_of_vtable(), vtable_length() / vtableEntry::size());
   403 }
   405 klassItable* InstanceKlass::itable() const {
   406   return new klassItable(instanceKlassHandle(this));
   407 }
   409 void InstanceKlass::eager_initialize(Thread *thread) {
   410   if (!EagerInitialization) return;
   412   if (this->is_not_initialized()) {
   413     // abort if the the class has a class initializer
   414     if (this->class_initializer() != NULL) return;
   416     // abort if it is java.lang.Object (initialization is handled in genesis)
   417     Klass* super = this->super();
   418     if (super == NULL) return;
   420     // abort if the super class should be initialized
   421     if (!InstanceKlass::cast(super)->is_initialized()) return;
   423     // call body to expose the this pointer
   424     instanceKlassHandle this_oop(thread, this);
   425     eager_initialize_impl(this_oop);
   426   }
   427 }
   430 void InstanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
   431   EXCEPTION_MARK;
   432   volatile oop init_lock = this_oop->init_lock();
   433   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   435   // abort if someone beat us to the initialization
   436   if (!this_oop->is_not_initialized()) return;  // note: not equivalent to is_initialized()
   438   ClassState old_state = this_oop->init_state();
   439   link_class_impl(this_oop, true, THREAD);
   440   if (HAS_PENDING_EXCEPTION) {
   441     CLEAR_PENDING_EXCEPTION;
   442     // Abort if linking the class throws an exception.
   444     // Use a test to avoid redundantly resetting the state if there's
   445     // no change.  Set_init_state() asserts that state changes make
   446     // progress, whereas here we might just be spinning in place.
   447     if( old_state != this_oop->_init_state )
   448       this_oop->set_init_state (old_state);
   449   } else {
   450     // linking successfull, mark class as initialized
   451     this_oop->set_init_state (fully_initialized);
   452     this_oop->fence_and_clear_init_lock();
   453     // trace
   454     if (TraceClassInitialization) {
   455       ResourceMark rm(THREAD);
   456       tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
   457     }
   458   }
   459 }
   462 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
   463 // process. The step comments refers to the procedure described in that section.
   464 // Note: implementation moved to static method to expose the this pointer.
   465 void InstanceKlass::initialize(TRAPS) {
   466   if (this->should_be_initialized()) {
   467     HandleMark hm(THREAD);
   468     instanceKlassHandle this_oop(THREAD, this);
   469     initialize_impl(this_oop, CHECK);
   470     // Note: at this point the class may be initialized
   471     //       OR it may be in the state of being initialized
   472     //       in case of recursive initialization!
   473   } else {
   474     assert(is_initialized(), "sanity check");
   475   }
   476 }
   479 bool InstanceKlass::verify_code(
   480     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
   481   // 1) Verify the bytecodes
   482   Verifier::Mode mode =
   483     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
   484   return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
   485 }
   488 // Used exclusively by the shared spaces dump mechanism to prevent
   489 // classes mapped into the shared regions in new VMs from appearing linked.
   491 void InstanceKlass::unlink_class() {
   492   assert(is_linked(), "must be linked");
   493   _init_state = loaded;
   494 }
   496 void InstanceKlass::link_class(TRAPS) {
   497   assert(is_loaded(), "must be loaded");
   498   if (!is_linked()) {
   499     HandleMark hm(THREAD);
   500     instanceKlassHandle this_oop(THREAD, this);
   501     link_class_impl(this_oop, true, CHECK);
   502   }
   503 }
   505 // Called to verify that a class can link during initialization, without
   506 // throwing a VerifyError.
   507 bool InstanceKlass::link_class_or_fail(TRAPS) {
   508   assert(is_loaded(), "must be loaded");
   509   if (!is_linked()) {
   510     HandleMark hm(THREAD);
   511     instanceKlassHandle this_oop(THREAD, this);
   512     link_class_impl(this_oop, false, CHECK_false);
   513   }
   514   return is_linked();
   515 }
   517 bool InstanceKlass::link_class_impl(
   518     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
   519   // check for error state
   520   if (this_oop->is_in_error_state()) {
   521     ResourceMark rm(THREAD);
   522     THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
   523                this_oop->external_name(), false);
   524   }
   525   // return if already verified
   526   if (this_oop->is_linked()) {
   527     return true;
   528   }
   530   // Timing
   531   // timer handles recursion
   532   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
   533   JavaThread* jt = (JavaThread*)THREAD;
   535   // link super class before linking this class
   536   instanceKlassHandle super(THREAD, this_oop->super());
   537   if (super.not_null()) {
   538     if (super->is_interface()) {  // check if super class is an interface
   539       ResourceMark rm(THREAD);
   540       Exceptions::fthrow(
   541         THREAD_AND_LOCATION,
   542         vmSymbols::java_lang_IncompatibleClassChangeError(),
   543         "class %s has interface %s as super class",
   544         this_oop->external_name(),
   545         super->external_name()
   546       );
   547       return false;
   548     }
   550     link_class_impl(super, throw_verifyerror, CHECK_false);
   551   }
   553   // link all interfaces implemented by this class before linking this class
   554   Array<Klass*>* interfaces = this_oop->local_interfaces();
   555   int num_interfaces = interfaces->length();
   556   for (int index = 0; index < num_interfaces; index++) {
   557     HandleMark hm(THREAD);
   558     instanceKlassHandle ih(THREAD, interfaces->at(index));
   559     link_class_impl(ih, throw_verifyerror, CHECK_false);
   560   }
   562   // in case the class is linked in the process of linking its superclasses
   563   if (this_oop->is_linked()) {
   564     return true;
   565   }
   567   // trace only the link time for this klass that includes
   568   // the verification time
   569   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
   570                              ClassLoader::perf_class_link_selftime(),
   571                              ClassLoader::perf_classes_linked(),
   572                              jt->get_thread_stat()->perf_recursion_counts_addr(),
   573                              jt->get_thread_stat()->perf_timers_addr(),
   574                              PerfClassTraceTime::CLASS_LINK);
   576   // verification & rewriting
   577   {
   578     volatile oop init_lock = this_oop->init_lock();
   579     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   580     // rewritten will have been set if loader constraint error found
   581     // on an earlier link attempt
   582     // don't verify or rewrite if already rewritten
   584     if (!this_oop->is_linked()) {
   585       if (!this_oop->is_rewritten()) {
   586         {
   587           // Timer includes any side effects of class verification (resolution,
   588           // etc), but not recursive entry into verify_code().
   589           PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
   590                                    ClassLoader::perf_class_verify_selftime(),
   591                                    ClassLoader::perf_classes_verified(),
   592                                    jt->get_thread_stat()->perf_recursion_counts_addr(),
   593                                    jt->get_thread_stat()->perf_timers_addr(),
   594                                    PerfClassTraceTime::CLASS_VERIFY);
   595           bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
   596           if (!verify_ok) {
   597             return false;
   598           }
   599         }
   601         // Just in case a side-effect of verify linked this class already
   602         // (which can sometimes happen since the verifier loads classes
   603         // using custom class loaders, which are free to initialize things)
   604         if (this_oop->is_linked()) {
   605           return true;
   606         }
   608         // also sets rewritten
   609         this_oop->rewrite_class(CHECK_false);
   610       }
   612       // relocate jsrs and link methods after they are all rewritten
   613       this_oop->relocate_and_link_methods(CHECK_false);
   615       // Initialize the vtable and interface table after
   616       // methods have been rewritten since rewrite may
   617       // fabricate new Method*s.
   618       // also does loader constraint checking
   619       if (!this_oop()->is_shared()) {
   620         ResourceMark rm(THREAD);
   621         this_oop->vtable()->initialize_vtable(true, CHECK_false);
   622         this_oop->itable()->initialize_itable(true, CHECK_false);
   623       }
   624 #ifdef ASSERT
   625       else {
   626         ResourceMark rm(THREAD);
   627         this_oop->vtable()->verify(tty, true);
   628         // In case itable verification is ever added.
   629         // this_oop->itable()->verify(tty, true);
   630       }
   631 #endif
   632       this_oop->set_init_state(linked);
   633       if (JvmtiExport::should_post_class_prepare()) {
   634         Thread *thread = THREAD;
   635         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
   636         JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
   637       }
   638     }
   639   }
   640   return true;
   641 }
   644 // Rewrite the byte codes of all of the methods of a class.
   645 // The rewriter must be called exactly once. Rewriting must happen after
   646 // verification but before the first method of the class is executed.
   647 void InstanceKlass::rewrite_class(TRAPS) {
   648   assert(is_loaded(), "must be loaded");
   649   instanceKlassHandle this_oop(THREAD, this);
   650   if (this_oop->is_rewritten()) {
   651     assert(this_oop()->is_shared(), "rewriting an unshared class?");
   652     return;
   653   }
   654   Rewriter::rewrite(this_oop, CHECK);
   655   this_oop->set_rewritten();
   656 }
   658 // Now relocate and link method entry points after class is rewritten.
   659 // This is outside is_rewritten flag. In case of an exception, it can be
   660 // executed more than once.
   661 void InstanceKlass::relocate_and_link_methods(TRAPS) {
   662   assert(is_loaded(), "must be loaded");
   663   instanceKlassHandle this_oop(THREAD, this);
   664   Rewriter::relocate_and_link(this_oop, CHECK);
   665 }
   668 void InstanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
   669   // Make sure klass is linked (verified) before initialization
   670   // A class could already be verified, since it has been reflected upon.
   671   this_oop->link_class(CHECK);
   673   DTRACE_CLASSINIT_PROBE(required, InstanceKlass::cast(this_oop()), -1);
   675   bool wait = false;
   677   // refer to the JVM book page 47 for description of steps
   678   // Step 1
   679   {
   680     volatile oop init_lock = this_oop->init_lock();
   681     ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   683     Thread *self = THREAD; // it's passed the current thread
   685     // Step 2
   686     // If we were to use wait() instead of waitInterruptibly() then
   687     // we might end up throwing IE from link/symbol resolution sites
   688     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
   689     while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
   690         wait = true;
   691       ol.waitUninterruptibly(CHECK);
   692     }
   694     // Step 3
   695     if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
   696       DTRACE_CLASSINIT_PROBE_WAIT(recursive, InstanceKlass::cast(this_oop()), -1,wait);
   697       return;
   698     }
   700     // Step 4
   701     if (this_oop->is_initialized()) {
   702       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, InstanceKlass::cast(this_oop()), -1,wait);
   703       return;
   704     }
   706     // Step 5
   707     if (this_oop->is_in_error_state()) {
   708       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, InstanceKlass::cast(this_oop()), -1,wait);
   709       ResourceMark rm(THREAD);
   710       const char* desc = "Could not initialize class ";
   711       const char* className = this_oop->external_name();
   712       size_t msglen = strlen(desc) + strlen(className) + 1;
   713       char* message = NEW_RESOURCE_ARRAY(char, msglen);
   714       if (NULL == message) {
   715         // Out of memory: can't create detailed error message
   716         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
   717       } else {
   718         jio_snprintf(message, msglen, "%s%s", desc, className);
   719         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
   720       }
   721     }
   723     // Step 6
   724     this_oop->set_init_state(being_initialized);
   725     this_oop->set_init_thread(self);
   726   }
   728   // Step 7
   729   Klass* super_klass = this_oop->super();
   730   if (super_klass != NULL && !this_oop->is_interface() && Klass::cast(super_klass)->should_be_initialized()) {
   731     Klass::cast(super_klass)->initialize(THREAD);
   733     if (HAS_PENDING_EXCEPTION) {
   734       Handle e(THREAD, PENDING_EXCEPTION);
   735       CLEAR_PENDING_EXCEPTION;
   736       {
   737         EXCEPTION_MARK;
   738         this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
   739         CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, superclass initialization error is thrown below
   740       }
   741       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, InstanceKlass::cast(this_oop()), -1,wait);
   742       THROW_OOP(e());
   743     }
   744   }
   746   if (this_oop->has_default_methods()) {
   747     // Step 7.5: initialize any interfaces which have default methods
   748     for (int i = 0; i < this_oop->local_interfaces()->length(); ++i) {
   749       Klass* iface = this_oop->local_interfaces()->at(i);
   750       InstanceKlass* ik = InstanceKlass::cast(iface);
   751       if (ik->has_default_methods() && ik->should_be_initialized()) {
   752         ik->initialize(THREAD);
   754         if (HAS_PENDING_EXCEPTION) {
   755           Handle e(THREAD, PENDING_EXCEPTION);
   756           CLEAR_PENDING_EXCEPTION;
   757           {
   758             EXCEPTION_MARK;
   759             // Locks object, set state, and notify all waiting threads
   760             this_oop->set_initialization_state_and_notify(
   761                 initialization_error, THREAD);
   763             // ignore any exception thrown, superclass initialization error is
   764             // thrown below
   765             CLEAR_PENDING_EXCEPTION;
   766           }
   767           DTRACE_CLASSINIT_PROBE_WAIT(
   768               super__failed, InstanceKlass::cast(this_oop()), -1, wait);
   769           THROW_OOP(e());
   770         }
   771       }
   772     }
   773   }
   775   // Step 8
   776   {
   777     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
   778     JavaThread* jt = (JavaThread*)THREAD;
   779     DTRACE_CLASSINIT_PROBE_WAIT(clinit, InstanceKlass::cast(this_oop()), -1,wait);
   780     // Timer includes any side effects of class initialization (resolution,
   781     // etc), but not recursive entry into call_class_initializer().
   782     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
   783                              ClassLoader::perf_class_init_selftime(),
   784                              ClassLoader::perf_classes_inited(),
   785                              jt->get_thread_stat()->perf_recursion_counts_addr(),
   786                              jt->get_thread_stat()->perf_timers_addr(),
   787                              PerfClassTraceTime::CLASS_CLINIT);
   788     this_oop->call_class_initializer(THREAD);
   789   }
   791   // Step 9
   792   if (!HAS_PENDING_EXCEPTION) {
   793     this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
   794     { ResourceMark rm(THREAD);
   795       debug_only(this_oop->vtable()->verify(tty, true);)
   796     }
   797   }
   798   else {
   799     // Step 10 and 11
   800     Handle e(THREAD, PENDING_EXCEPTION);
   801     CLEAR_PENDING_EXCEPTION;
   802     {
   803       EXCEPTION_MARK;
   804       this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
   805       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
   806     }
   807     DTRACE_CLASSINIT_PROBE_WAIT(error, InstanceKlass::cast(this_oop()), -1,wait);
   808     if (e->is_a(SystemDictionary::Error_klass())) {
   809       THROW_OOP(e());
   810     } else {
   811       JavaCallArguments args(e);
   812       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
   813                 vmSymbols::throwable_void_signature(),
   814                 &args);
   815     }
   816   }
   817   DTRACE_CLASSINIT_PROBE_WAIT(end, InstanceKlass::cast(this_oop()), -1,wait);
   818 }
   821 // Note: implementation moved to static method to expose the this pointer.
   822 void InstanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
   823   instanceKlassHandle kh(THREAD, this);
   824   set_initialization_state_and_notify_impl(kh, state, CHECK);
   825 }
   827 void InstanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
   828   volatile oop init_lock = this_oop->init_lock();
   829   ObjectLocker ol(init_lock, THREAD, init_lock != NULL);
   830   this_oop->set_init_state(state);
   831   this_oop->fence_and_clear_init_lock();
   832   ol.notify_all(CHECK);
   833 }
   835 // The embedded _implementor field can only record one implementor.
   836 // When there are more than one implementors, the _implementor field
   837 // is set to the interface Klass* itself. Following are the possible
   838 // values for the _implementor field:
   839 //   NULL                  - no implementor
   840 //   implementor Klass*    - one implementor
   841 //   self                  - more than one implementor
   842 //
   843 // The _implementor field only exists for interfaces.
   844 void InstanceKlass::add_implementor(Klass* k) {
   845   assert(Compile_lock->owned_by_self(), "");
   846   assert(is_interface(), "not interface");
   847   // Filter out my subinterfaces.
   848   // (Note: Interfaces are never on the subklass list.)
   849   if (InstanceKlass::cast(k)->is_interface()) return;
   851   // Filter out subclasses whose supers already implement me.
   852   // (Note: CHA must walk subclasses of direct implementors
   853   // in order to locate indirect implementors.)
   854   Klass* sk = InstanceKlass::cast(k)->super();
   855   if (sk != NULL && InstanceKlass::cast(sk)->implements_interface(this))
   856     // We only need to check one immediate superclass, since the
   857     // implements_interface query looks at transitive_interfaces.
   858     // Any supers of the super have the same (or fewer) transitive_interfaces.
   859     return;
   861   Klass* ik = implementor();
   862   if (ik == NULL) {
   863     set_implementor(k);
   864   } else if (ik != this) {
   865     // There is already an implementor. Use itself as an indicator of
   866     // more than one implementors.
   867     set_implementor(this);
   868   }
   870   // The implementor also implements the transitive_interfaces
   871   for (int index = 0; index < local_interfaces()->length(); index++) {
   872     InstanceKlass::cast(local_interfaces()->at(index))->add_implementor(k);
   873   }
   874 }
   876 void InstanceKlass::init_implementor() {
   877   if (is_interface()) {
   878     set_implementor(NULL);
   879   }
   880 }
   883 void InstanceKlass::process_interfaces(Thread *thread) {
   884   // link this class into the implementors list of every interface it implements
   885   Klass* this_as_klass_oop = this;
   886   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
   887     assert(local_interfaces()->at(i)->is_klass(), "must be a klass");
   888     InstanceKlass* interf = InstanceKlass::cast(local_interfaces()->at(i));
   889     assert(interf->is_interface(), "expected interface");
   890     interf->add_implementor(this_as_klass_oop);
   891   }
   892 }
   894 bool InstanceKlass::can_be_primary_super_slow() const {
   895   if (is_interface())
   896     return false;
   897   else
   898     return Klass::can_be_primary_super_slow();
   899 }
   901 GrowableArray<Klass*>* InstanceKlass::compute_secondary_supers(int num_extra_slots) {
   902   // The secondaries are the implemented interfaces.
   903   InstanceKlass* ik = InstanceKlass::cast(this);
   904   Array<Klass*>* interfaces = ik->transitive_interfaces();
   905   int num_secondaries = num_extra_slots + interfaces->length();
   906   if (num_secondaries == 0) {
   907     // Must share this for correct bootstrapping!
   908     set_secondary_supers(Universe::the_empty_klass_array());
   909     return NULL;
   910   } else if (num_extra_slots == 0) {
   911     // The secondary super list is exactly the same as the transitive interfaces.
   912     // Redefine classes has to be careful not to delete this!
   913     set_secondary_supers(interfaces);
   914     return NULL;
   915   } else {
   916     // Copy transitive interfaces to a temporary growable array to be constructed
   917     // into the secondary super list with extra slots.
   918     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(interfaces->length());
   919     for (int i = 0; i < interfaces->length(); i++) {
   920       secondaries->push(interfaces->at(i));
   921     }
   922     return secondaries;
   923   }
   924 }
   926 bool InstanceKlass::compute_is_subtype_of(Klass* k) {
   927   if (Klass::cast(k)->is_interface()) {
   928     return implements_interface(k);
   929   } else {
   930     return Klass::compute_is_subtype_of(k);
   931   }
   932 }
   934 bool InstanceKlass::implements_interface(Klass* k) const {
   935   if (this == k) return true;
   936   assert(Klass::cast(k)->is_interface(), "should be an interface class");
   937   for (int i = 0; i < transitive_interfaces()->length(); i++) {
   938     if (transitive_interfaces()->at(i) == k) {
   939       return true;
   940     }
   941   }
   942   return false;
   943 }
   945 objArrayOop InstanceKlass::allocate_objArray(int n, int length, TRAPS) {
   946   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
   947   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
   948     report_java_out_of_memory("Requested array size exceeds VM limit");
   949     JvmtiExport::post_array_size_exhausted();
   950     THROW_OOP_0(Universe::out_of_memory_error_array_size());
   951   }
   952   int size = objArrayOopDesc::object_size(length);
   953   Klass* ak = array_klass(n, CHECK_NULL);
   954   KlassHandle h_ak (THREAD, ak);
   955   objArrayOop o =
   956     (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
   957   return o;
   958 }
   960 instanceOop InstanceKlass::register_finalizer(instanceOop i, TRAPS) {
   961   if (TraceFinalizerRegistration) {
   962     tty->print("Registered ");
   963     i->print_value_on(tty);
   964     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
   965   }
   966   instanceHandle h_i(THREAD, i);
   967   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
   968   JavaValue result(T_VOID);
   969   JavaCallArguments args(h_i);
   970   methodHandle mh (THREAD, Universe::finalizer_register_method());
   971   JavaCalls::call(&result, mh, &args, CHECK_NULL);
   972   return h_i();
   973 }
   975 instanceOop InstanceKlass::allocate_instance(TRAPS) {
   976   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
   977   int size = size_helper();  // Query before forming handle.
   979   KlassHandle h_k(THREAD, this);
   981   instanceOop i;
   983   i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
   984   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
   985     i = register_finalizer(i, CHECK_NULL);
   986   }
   987   return i;
   988 }
   990 void InstanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
   991   if (is_interface() || is_abstract()) {
   992     ResourceMark rm(THREAD);
   993     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
   994               : vmSymbols::java_lang_InstantiationException(), external_name());
   995   }
   996   if (this == SystemDictionary::Class_klass()) {
   997     ResourceMark rm(THREAD);
   998     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
   999               : vmSymbols::java_lang_IllegalAccessException(), external_name());
  1003 Klass* InstanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
  1004   instanceKlassHandle this_oop(THREAD, this);
  1005   return array_klass_impl(this_oop, or_null, n, THREAD);
  1008 Klass* InstanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
  1009   if (this_oop->array_klasses() == NULL) {
  1010     if (or_null) return NULL;
  1012     ResourceMark rm;
  1013     JavaThread *jt = (JavaThread *)THREAD;
  1015       // Atomic creation of array_klasses
  1016       MutexLocker mc(Compile_lock, THREAD);   // for vtables
  1017       MutexLocker ma(MultiArray_lock, THREAD);
  1019       // Check if update has already taken place
  1020       if (this_oop->array_klasses() == NULL) {
  1021         Klass*    k = ObjArrayKlass::allocate_objArray_klass(this_oop->class_loader_data(), 1, this_oop, CHECK_NULL);
  1022         this_oop->set_array_klasses(k);
  1026   // _this will always be set at this point
  1027   ObjArrayKlass* oak = (ObjArrayKlass*)this_oop->array_klasses();
  1028   if (or_null) {
  1029     return oak->array_klass_or_null(n);
  1031   return oak->array_klass(n, CHECK_NULL);
  1034 Klass* InstanceKlass::array_klass_impl(bool or_null, TRAPS) {
  1035   return array_klass_impl(or_null, 1, THREAD);
  1038 void InstanceKlass::call_class_initializer(TRAPS) {
  1039   instanceKlassHandle ik (THREAD, this);
  1040   call_class_initializer_impl(ik, THREAD);
  1043 static int call_class_initializer_impl_counter = 0;   // for debugging
  1045 Method* InstanceKlass::class_initializer() {
  1046   Method* clinit = find_method(
  1047       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
  1048   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
  1049     return clinit;
  1051   return NULL;
  1054 void InstanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
  1055   methodHandle h_method(THREAD, this_oop->class_initializer());
  1056   assert(!this_oop->is_initialized(), "we cannot initialize twice");
  1057   if (TraceClassInitialization) {
  1058     tty->print("%d Initializing ", call_class_initializer_impl_counter++);
  1059     this_oop->name()->print_value();
  1060     tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
  1062   if (h_method() != NULL) {
  1063     JavaCallArguments args; // No arguments
  1064     JavaValue result(T_VOID);
  1065     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
  1070 void InstanceKlass::mask_for(methodHandle method, int bci,
  1071   InterpreterOopMap* entry_for) {
  1072   // Dirty read, then double-check under a lock.
  1073   if (_oop_map_cache == NULL) {
  1074     // Otherwise, allocate a new one.
  1075     MutexLocker x(OopMapCacheAlloc_lock);
  1076     // First time use. Allocate a cache in C heap
  1077     if (_oop_map_cache == NULL) {
  1078       _oop_map_cache = new OopMapCache();
  1081   // _oop_map_cache is constant after init; lookup below does is own locking.
  1082   _oop_map_cache->lookup(method, bci, entry_for);
  1086 bool InstanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  1087   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
  1088     Symbol* f_name = fs.name();
  1089     Symbol* f_sig  = fs.signature();
  1090     if (f_name == name && f_sig == sig) {
  1091       fd->initialize(const_cast<InstanceKlass*>(this), fs.index());
  1092       return true;
  1095   return false;
  1099 Klass* InstanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  1100   const int n = local_interfaces()->length();
  1101   for (int i = 0; i < n; i++) {
  1102     Klass* intf1 = local_interfaces()->at(i);
  1103     assert(Klass::cast(intf1)->is_interface(), "just checking type");
  1104     // search for field in current interface
  1105     if (InstanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
  1106       assert(fd->is_static(), "interface field must be static");
  1107       return intf1;
  1109     // search for field in direct superinterfaces
  1110     Klass* intf2 = InstanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
  1111     if (intf2 != NULL) return intf2;
  1113   // otherwise field lookup fails
  1114   return NULL;
  1118 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
  1119   // search order according to newest JVM spec (5.4.3.2, p.167).
  1120   // 1) search for field in current klass
  1121   if (find_local_field(name, sig, fd)) {
  1122     return const_cast<InstanceKlass*>(this);
  1124   // 2) search for field recursively in direct superinterfaces
  1125   { Klass* intf = find_interface_field(name, sig, fd);
  1126     if (intf != NULL) return intf;
  1128   // 3) apply field lookup recursively if superclass exists
  1129   { Klass* supr = super();
  1130     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, fd);
  1132   // 4) otherwise field lookup fails
  1133   return NULL;
  1137 Klass* InstanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
  1138   // search order according to newest JVM spec (5.4.3.2, p.167).
  1139   // 1) search for field in current klass
  1140   if (find_local_field(name, sig, fd)) {
  1141     if (fd->is_static() == is_static) return const_cast<InstanceKlass*>(this);
  1143   // 2) search for field recursively in direct superinterfaces
  1144   if (is_static) {
  1145     Klass* intf = find_interface_field(name, sig, fd);
  1146     if (intf != NULL) return intf;
  1148   // 3) apply field lookup recursively if superclass exists
  1149   { Klass* supr = super();
  1150     if (supr != NULL) return InstanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
  1152   // 4) otherwise field lookup fails
  1153   return NULL;
  1157 bool InstanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
  1158   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
  1159     if (fs.offset() == offset) {
  1160       fd->initialize(const_cast<InstanceKlass*>(this), fs.index());
  1161       if (fd->is_static() == is_static) return true;
  1164   return false;
  1168 bool InstanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
  1169   Klass* klass = const_cast<InstanceKlass*>(this);
  1170   while (klass != NULL) {
  1171     if (InstanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
  1172       return true;
  1174     klass = Klass::cast(klass)->super();
  1176   return false;
  1180 void InstanceKlass::methods_do(void f(Method* method)) {
  1181   int len = methods()->length();
  1182   for (int index = 0; index < len; index++) {
  1183     Method* m = methods()->at(index);
  1184     assert(m->is_method(), "must be method");
  1185     f(m);
  1190 void InstanceKlass::do_local_static_fields(FieldClosure* cl) {
  1191   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
  1192     if (fs.access_flags().is_static()) {
  1193       fieldDescriptor fd;
  1194       fd.initialize(this, fs.index());
  1195       cl->do_field(&fd);
  1201 void InstanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
  1202   instanceKlassHandle h_this(THREAD, this);
  1203   do_local_static_fields_impl(h_this, f, CHECK);
  1207 void InstanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
  1208   for (JavaFieldStream fs(this_oop()); !fs.done(); fs.next()) {
  1209     if (fs.access_flags().is_static()) {
  1210       fieldDescriptor fd;
  1211       fd.initialize(this_oop(), fs.index());
  1212       f(&fd, CHECK);
  1218 static int compare_fields_by_offset(int* a, int* b) {
  1219   return a[0] - b[0];
  1222 void InstanceKlass::do_nonstatic_fields(FieldClosure* cl) {
  1223   InstanceKlass* super = superklass();
  1224   if (super != NULL) {
  1225     super->do_nonstatic_fields(cl);
  1227   fieldDescriptor fd;
  1228   int length = java_fields_count();
  1229   // In DebugInfo nonstatic fields are sorted by offset.
  1230   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1), mtClass);
  1231   int j = 0;
  1232   for (int i = 0; i < length; i += 1) {
  1233     fd.initialize(this, i);
  1234     if (!fd.is_static()) {
  1235       fields_sorted[j + 0] = fd.offset();
  1236       fields_sorted[j + 1] = i;
  1237       j += 2;
  1240   if (j > 0) {
  1241     length = j;
  1242     // _sort_Fn is defined in growableArray.hpp.
  1243     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
  1244     for (int i = 0; i < length; i += 2) {
  1245       fd.initialize(this, fields_sorted[i + 1]);
  1246       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
  1247       cl->do_field(&fd);
  1250   FREE_C_HEAP_ARRAY(int, fields_sorted, mtClass);
  1254 void InstanceKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
  1255   if (array_klasses() != NULL)
  1256     ArrayKlass::cast(array_klasses())->array_klasses_do(f, THREAD);
  1259 void InstanceKlass::array_klasses_do(void f(Klass* k)) {
  1260   if (array_klasses() != NULL)
  1261     ArrayKlass::cast(array_klasses())->array_klasses_do(f);
  1265 void InstanceKlass::with_array_klasses_do(void f(Klass* k)) {
  1266   f(this);
  1267   array_klasses_do(f);
  1270 #ifdef ASSERT
  1271 static int linear_search(Array<Method*>* methods, Symbol* name, Symbol* signature) {
  1272   int len = methods->length();
  1273   for (int index = 0; index < len; index++) {
  1274     Method* m = methods->at(index);
  1275     assert(m->is_method(), "must be method");
  1276     if (m->signature() == signature && m->name() == name) {
  1277        return index;
  1280   return -1;
  1282 #endif
  1284 static int binary_search(Array<Method*>* methods, Symbol* name) {
  1285   int len = methods->length();
  1286   // methods are sorted, so do binary search
  1287   int l = 0;
  1288   int h = len - 1;
  1289   while (l <= h) {
  1290     int mid = (l + h) >> 1;
  1291     Method* m = methods->at(mid);
  1292     assert(m->is_method(), "must be method");
  1293     int res = m->name()->fast_compare(name);
  1294     if (res == 0) {
  1295       return mid;
  1296     } else if (res < 0) {
  1297       l = mid + 1;
  1298     } else {
  1299       h = mid - 1;
  1302   return -1;
  1305 Method* InstanceKlass::find_method(Symbol* name, Symbol* signature) const {
  1306   return InstanceKlass::find_method(methods(), name, signature);
  1309 Method* InstanceKlass::find_method(
  1310     Array<Method*>* methods, Symbol* name, Symbol* signature) {
  1311   int hit = binary_search(methods, name);
  1312   if (hit != -1) {
  1313     Method* m = methods->at(hit);
  1314     // Do linear search to find matching signature.  First, quick check
  1315     // for common case
  1316     if (m->signature() == signature) return m;
  1317     // search downwards through overloaded methods
  1318     int i;
  1319     for (i = hit - 1; i >= 0; --i) {
  1320         Method* m = methods->at(i);
  1321         assert(m->is_method(), "must be method");
  1322         if (m->name() != name) break;
  1323         if (m->signature() == signature) return m;
  1325     // search upwards
  1326     for (i = hit + 1; i < methods->length(); ++i) {
  1327         Method* m = methods->at(i);
  1328         assert(m->is_method(), "must be method");
  1329         if (m->name() != name) break;
  1330         if (m->signature() == signature) return m;
  1332     // not found
  1333 #ifdef ASSERT
  1334     int index = linear_search(methods, name, signature);
  1335     assert(index == -1, err_msg("binary search should have found entry %d", index));
  1336 #endif
  1338   return NULL;
  1341 int InstanceKlass::find_method_by_name(Symbol* name, int* end) {
  1342   return find_method_by_name(methods(), name, end);
  1345 int InstanceKlass::find_method_by_name(
  1346     Array<Method*>* methods, Symbol* name, int* end_ptr) {
  1347   assert(end_ptr != NULL, "just checking");
  1348   int start = binary_search(methods, name);
  1349   int end = start + 1;
  1350   if (start != -1) {
  1351     while (start - 1 >= 0 && (methods->at(start - 1))->name() == name) --start;
  1352     while (end < methods->length() && (methods->at(end))->name() == name) ++end;
  1353     *end_ptr = end;
  1354     return start;
  1356   return -1;
  1359 Method* InstanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
  1360   Klass* klass = const_cast<InstanceKlass*>(this);
  1361   while (klass != NULL) {
  1362     Method* method = InstanceKlass::cast(klass)->find_method(name, signature);
  1363     if (method != NULL) return method;
  1364     klass = InstanceKlass::cast(klass)->super();
  1366   return NULL;
  1369 // lookup a method in all the interfaces that this class implements
  1370 Method* InstanceKlass::lookup_method_in_all_interfaces(Symbol* name,
  1371                                                          Symbol* signature) const {
  1372   Array<Klass*>* all_ifs = transitive_interfaces();
  1373   int num_ifs = all_ifs->length();
  1374   InstanceKlass *ik = NULL;
  1375   for (int i = 0; i < num_ifs; i++) {
  1376     ik = InstanceKlass::cast(all_ifs->at(i));
  1377     Method* m = ik->lookup_method(name, signature);
  1378     if (m != NULL) {
  1379       return m;
  1382   return NULL;
  1385 /* jni_id_for_impl for jfieldIds only */
  1386 JNIid* InstanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
  1387   MutexLocker ml(JfieldIdCreation_lock);
  1388   // Retry lookup after we got the lock
  1389   JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
  1390   if (probe == NULL) {
  1391     // Slow case, allocate new static field identifier
  1392     probe = new JNIid(this_oop(), offset, this_oop->jni_ids());
  1393     this_oop->set_jni_ids(probe);
  1395   return probe;
  1399 /* jni_id_for for jfieldIds only */
  1400 JNIid* InstanceKlass::jni_id_for(int offset) {
  1401   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
  1402   if (probe == NULL) {
  1403     probe = jni_id_for_impl(this, offset);
  1405   return probe;
  1408 u2 InstanceKlass::enclosing_method_data(int offset) {
  1409   Array<jushort>* inner_class_list = inner_classes();
  1410   if (inner_class_list == NULL) {
  1411     return 0;
  1413   int length = inner_class_list->length();
  1414   if (length % inner_class_next_offset == 0) {
  1415     return 0;
  1416   } else {
  1417     int index = length - enclosing_method_attribute_size;
  1418     assert(offset < enclosing_method_attribute_size, "invalid offset");
  1419     return inner_class_list->at(index + offset);
  1423 void InstanceKlass::set_enclosing_method_indices(u2 class_index,
  1424                                                  u2 method_index) {
  1425   Array<jushort>* inner_class_list = inner_classes();
  1426   assert (inner_class_list != NULL, "_inner_classes list is not set up");
  1427   int length = inner_class_list->length();
  1428   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
  1429     int index = length - enclosing_method_attribute_size;
  1430     inner_class_list->at_put(
  1431       index + enclosing_method_class_index_offset, class_index);
  1432     inner_class_list->at_put(
  1433       index + enclosing_method_method_index_offset, method_index);
  1437 // Lookup or create a jmethodID.
  1438 // This code is called by the VMThread and JavaThreads so the
  1439 // locking has to be done very carefully to avoid deadlocks
  1440 // and/or other cache consistency problems.
  1441 //
  1442 jmethodID InstanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
  1443   size_t idnum = (size_t)method_h->method_idnum();
  1444   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
  1445   size_t length = 0;
  1446   jmethodID id = NULL;
  1448   // We use a double-check locking idiom here because this cache is
  1449   // performance sensitive. In the normal system, this cache only
  1450   // transitions from NULL to non-NULL which is safe because we use
  1451   // release_set_methods_jmethod_ids() to advertise the new cache.
  1452   // A partially constructed cache should never be seen by a racing
  1453   // thread. We also use release_store_ptr() to save a new jmethodID
  1454   // in the cache so a partially constructed jmethodID should never be
  1455   // seen either. Cache reads of existing jmethodIDs proceed without a
  1456   // lock, but cache writes of a new jmethodID requires uniqueness and
  1457   // creation of the cache itself requires no leaks so a lock is
  1458   // generally acquired in those two cases.
  1459   //
  1460   // If the RedefineClasses() API has been used, then this cache can
  1461   // grow and we'll have transitions from non-NULL to bigger non-NULL.
  1462   // Cache creation requires no leaks and we require safety between all
  1463   // cache accesses and freeing of the old cache so a lock is generally
  1464   // acquired when the RedefineClasses() API has been used.
  1466   if (jmeths != NULL) {
  1467     // the cache already exists
  1468     if (!ik_h->idnum_can_increment()) {
  1469       // the cache can't grow so we can just get the current values
  1470       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1471     } else {
  1472       // cache can grow so we have to be more careful
  1473       if (Threads::number_of_threads() == 0 ||
  1474           SafepointSynchronize::is_at_safepoint()) {
  1475         // we're single threaded or at a safepoint - no locking needed
  1476         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1477       } else {
  1478         MutexLocker ml(JmethodIdCreation_lock);
  1479         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1483   // implied else:
  1484   // we need to allocate a cache so default length and id values are good
  1486   if (jmeths == NULL ||   // no cache yet
  1487       length <= idnum ||  // cache is too short
  1488       id == NULL) {       // cache doesn't contain entry
  1490     // This function can be called by the VMThread so we have to do all
  1491     // things that might block on a safepoint before grabbing the lock.
  1492     // Otherwise, we can deadlock with the VMThread or have a cache
  1493     // consistency issue. These vars keep track of what we might have
  1494     // to free after the lock is dropped.
  1495     jmethodID  to_dealloc_id     = NULL;
  1496     jmethodID* to_dealloc_jmeths = NULL;
  1498     // may not allocate new_jmeths or use it if we allocate it
  1499     jmethodID* new_jmeths = NULL;
  1500     if (length <= idnum) {
  1501       // allocate a new cache that might be used
  1502       size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
  1503       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1, mtClass);
  1504       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
  1505       // cache size is stored in element[0], other elements offset by one
  1506       new_jmeths[0] = (jmethodID)size;
  1509     // allocate a new jmethodID that might be used
  1510     jmethodID new_id = NULL;
  1511     if (method_h->is_old() && !method_h->is_obsolete()) {
  1512       // The method passed in is old (but not obsolete), we need to use the current version
  1513       Method* current_method = ik_h->method_with_idnum((int)idnum);
  1514       assert(current_method != NULL, "old and but not obsolete, so should exist");
  1515       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), current_method);
  1516     } else {
  1517       // It is the current version of the method or an obsolete method,
  1518       // use the version passed in
  1519       new_id = Method::make_jmethod_id(ik_h->class_loader_data(), method_h());
  1522     if (Threads::number_of_threads() == 0 ||
  1523         SafepointSynchronize::is_at_safepoint()) {
  1524       // we're single threaded or at a safepoint - no locking needed
  1525       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
  1526                                           &to_dealloc_id, &to_dealloc_jmeths);
  1527     } else {
  1528       MutexLocker ml(JmethodIdCreation_lock);
  1529       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
  1530                                           &to_dealloc_id, &to_dealloc_jmeths);
  1533     // The lock has been dropped so we can free resources.
  1534     // Free up either the old cache or the new cache if we allocated one.
  1535     if (to_dealloc_jmeths != NULL) {
  1536       FreeHeap(to_dealloc_jmeths);
  1538     // free up the new ID since it wasn't needed
  1539     if (to_dealloc_id != NULL) {
  1540       Method::destroy_jmethod_id(ik_h->class_loader_data(), to_dealloc_id);
  1543   return id;
  1547 // Common code to fetch the jmethodID from the cache or update the
  1548 // cache with the new jmethodID. This function should never do anything
  1549 // that causes the caller to go to a safepoint or we can deadlock with
  1550 // the VMThread or have cache consistency issues.
  1551 //
  1552 jmethodID InstanceKlass::get_jmethod_id_fetch_or_update(
  1553             instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
  1554             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
  1555             jmethodID** to_dealloc_jmeths_p) {
  1556   assert(new_id != NULL, "sanity check");
  1557   assert(to_dealloc_id_p != NULL, "sanity check");
  1558   assert(to_dealloc_jmeths_p != NULL, "sanity check");
  1559   assert(Threads::number_of_threads() == 0 ||
  1560          SafepointSynchronize::is_at_safepoint() ||
  1561          JmethodIdCreation_lock->owned_by_self(), "sanity check");
  1563   // reacquire the cache - we are locked, single threaded or at a safepoint
  1564   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
  1565   jmethodID  id     = NULL;
  1566   size_t     length = 0;
  1568   if (jmeths == NULL ||                         // no cache yet
  1569       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
  1570     if (jmeths != NULL) {
  1571       // copy any existing entries from the old cache
  1572       for (size_t index = 0; index < length; index++) {
  1573         new_jmeths[index+1] = jmeths[index+1];
  1575       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
  1577     ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
  1578   } else {
  1579     // fetch jmethodID (if any) from the existing cache
  1580     id = jmeths[idnum+1];
  1581     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
  1583   if (id == NULL) {
  1584     // No matching jmethodID in the existing cache or we have a new
  1585     // cache or we just grew the cache. This cache write is done here
  1586     // by the first thread to win the foot race because a jmethodID
  1587     // needs to be unique once it is generally available.
  1588     id = new_id;
  1590     // The jmethodID cache can be read while unlocked so we have to
  1591     // make sure the new jmethodID is complete before installing it
  1592     // in the cache.
  1593     OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
  1594   } else {
  1595     *to_dealloc_id_p = new_id; // save new id for later delete
  1597   return id;
  1601 // Common code to get the jmethodID cache length and the jmethodID
  1602 // value at index idnum if there is one.
  1603 //
  1604 void InstanceKlass::get_jmethod_id_length_value(jmethodID* cache,
  1605        size_t idnum, size_t *length_p, jmethodID* id_p) {
  1606   assert(cache != NULL, "sanity check");
  1607   assert(length_p != NULL, "sanity check");
  1608   assert(id_p != NULL, "sanity check");
  1610   // cache size is stored in element[0], other elements offset by one
  1611   *length_p = (size_t)cache[0];
  1612   if (*length_p <= idnum) {  // cache is too short
  1613     *id_p = NULL;
  1614   } else {
  1615     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
  1620 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
  1621 jmethodID InstanceKlass::jmethod_id_or_null(Method* method) {
  1622   size_t idnum = (size_t)method->method_idnum();
  1623   jmethodID* jmeths = methods_jmethod_ids_acquire();
  1624   size_t length;                                // length assigned as debugging crumb
  1625   jmethodID id = NULL;
  1626   if (jmeths != NULL &&                         // If there is a cache
  1627       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
  1628     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
  1630   return id;
  1634 // Cache an itable index
  1635 void InstanceKlass::set_cached_itable_index(size_t idnum, int index) {
  1636   int* indices = methods_cached_itable_indices_acquire();
  1637   int* to_dealloc_indices = NULL;
  1639   // We use a double-check locking idiom here because this cache is
  1640   // performance sensitive. In the normal system, this cache only
  1641   // transitions from NULL to non-NULL which is safe because we use
  1642   // release_set_methods_cached_itable_indices() to advertise the
  1643   // new cache. A partially constructed cache should never be seen
  1644   // by a racing thread. Cache reads and writes proceed without a
  1645   // lock, but creation of the cache itself requires no leaks so a
  1646   // lock is generally acquired in that case.
  1647   //
  1648   // If the RedefineClasses() API has been used, then this cache can
  1649   // grow and we'll have transitions from non-NULL to bigger non-NULL.
  1650   // Cache creation requires no leaks and we require safety between all
  1651   // cache accesses and freeing of the old cache so a lock is generally
  1652   // acquired when the RedefineClasses() API has been used.
  1654   if (indices == NULL || idnum_can_increment()) {
  1655     // we need a cache or the cache can grow
  1656     MutexLocker ml(JNICachedItableIndex_lock);
  1657     // reacquire the cache to see if another thread already did the work
  1658     indices = methods_cached_itable_indices_acquire();
  1659     size_t length = 0;
  1660     // cache size is stored in element[0], other elements offset by one
  1661     if (indices == NULL || (length = (size_t)indices[0]) <= idnum) {
  1662       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
  1663       int* new_indices = NEW_C_HEAP_ARRAY(int, size+1, mtClass);
  1664       new_indices[0] = (int)size;
  1665       // copy any existing entries
  1666       size_t i;
  1667       for (i = 0; i < length; i++) {
  1668         new_indices[i+1] = indices[i+1];
  1670       // Set all the rest to -1
  1671       for (i = length; i < size; i++) {
  1672         new_indices[i+1] = -1;
  1674       if (indices != NULL) {
  1675         // We have an old cache to delete so save it for after we
  1676         // drop the lock.
  1677         to_dealloc_indices = indices;
  1679       release_set_methods_cached_itable_indices(indices = new_indices);
  1682     if (idnum_can_increment()) {
  1683       // this cache can grow so we have to write to it safely
  1684       indices[idnum+1] = index;
  1686   } else {
  1687     CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
  1690   if (!idnum_can_increment()) {
  1691     // The cache cannot grow and this JNI itable index value does not
  1692     // have to be unique like a jmethodID. If there is a race to set it,
  1693     // it doesn't matter.
  1694     indices[idnum+1] = index;
  1697   if (to_dealloc_indices != NULL) {
  1698     // we allocated a new cache so free the old one
  1699     FreeHeap(to_dealloc_indices);
  1704 // Retrieve a cached itable index
  1705 int InstanceKlass::cached_itable_index(size_t idnum) {
  1706   int* indices = methods_cached_itable_indices_acquire();
  1707   if (indices != NULL && ((size_t)indices[0]) > idnum) {
  1708      // indices exist and are long enough, retrieve possible cached
  1709     return indices[idnum+1];
  1711   return -1;
  1715 //
  1716 // Walk the list of dependent nmethods searching for nmethods which
  1717 // are dependent on the changes that were passed in and mark them for
  1718 // deoptimization.  Returns the number of nmethods found.
  1719 //
  1720 int InstanceKlass::mark_dependent_nmethods(DepChange& changes) {
  1721   assert_locked_or_safepoint(CodeCache_lock);
  1722   int found = 0;
  1723   nmethodBucket* b = _dependencies;
  1724   while (b != NULL) {
  1725     nmethod* nm = b->get_nmethod();
  1726     // since dependencies aren't removed until an nmethod becomes a zombie,
  1727     // the dependency list may contain nmethods which aren't alive.
  1728     if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
  1729       if (TraceDependencies) {
  1730         ResourceMark rm;
  1731         tty->print_cr("Marked for deoptimization");
  1732         tty->print_cr("  context = %s", this->external_name());
  1733         changes.print();
  1734         nm->print();
  1735         nm->print_dependencies();
  1737       nm->mark_for_deoptimization();
  1738       found++;
  1740     b = b->next();
  1742   return found;
  1746 //
  1747 // Add an nmethodBucket to the list of dependencies for this nmethod.
  1748 // It's possible that an nmethod has multiple dependencies on this klass
  1749 // so a count is kept for each bucket to guarantee that creation and
  1750 // deletion of dependencies is consistent.
  1751 //
  1752 void InstanceKlass::add_dependent_nmethod(nmethod* nm) {
  1753   assert_locked_or_safepoint(CodeCache_lock);
  1754   nmethodBucket* b = _dependencies;
  1755   nmethodBucket* last = NULL;
  1756   while (b != NULL) {
  1757     if (nm == b->get_nmethod()) {
  1758       b->increment();
  1759       return;
  1761     b = b->next();
  1763   _dependencies = new nmethodBucket(nm, _dependencies);
  1767 //
  1768 // Decrement count of the nmethod in the dependency list and remove
  1769 // the bucket competely when the count goes to 0.  This method must
  1770 // find a corresponding bucket otherwise there's a bug in the
  1771 // recording of dependecies.
  1772 //
  1773 void InstanceKlass::remove_dependent_nmethod(nmethod* nm) {
  1774   assert_locked_or_safepoint(CodeCache_lock);
  1775   nmethodBucket* b = _dependencies;
  1776   nmethodBucket* last = NULL;
  1777   while (b != NULL) {
  1778     if (nm == b->get_nmethod()) {
  1779       if (b->decrement() == 0) {
  1780         if (last == NULL) {
  1781           _dependencies = b->next();
  1782         } else {
  1783           last->set_next(b->next());
  1785         delete b;
  1787       return;
  1789     last = b;
  1790     b = b->next();
  1792 #ifdef ASSERT
  1793   tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
  1794   nm->print();
  1795 #endif // ASSERT
  1796   ShouldNotReachHere();
  1800 #ifndef PRODUCT
  1801 void InstanceKlass::print_dependent_nmethods(bool verbose) {
  1802   nmethodBucket* b = _dependencies;
  1803   int idx = 0;
  1804   while (b != NULL) {
  1805     nmethod* nm = b->get_nmethod();
  1806     tty->print("[%d] count=%d { ", idx++, b->count());
  1807     if (!verbose) {
  1808       nm->print_on(tty, "nmethod");
  1809       tty->print_cr(" } ");
  1810     } else {
  1811       nm->print();
  1812       nm->print_dependencies();
  1813       tty->print_cr("--- } ");
  1815     b = b->next();
  1820 bool InstanceKlass::is_dependent_nmethod(nmethod* nm) {
  1821   nmethodBucket* b = _dependencies;
  1822   while (b != NULL) {
  1823     if (nm == b->get_nmethod()) {
  1824       return true;
  1826     b = b->next();
  1828   return false;
  1830 #endif //PRODUCT
  1833 // Garbage collection
  1835 void InstanceKlass::oops_do(OopClosure* cl) {
  1836   Klass::oops_do(cl);
  1838   cl->do_oop(adr_protection_domain());
  1839   cl->do_oop(adr_signers());
  1840   cl->do_oop(adr_init_lock());
  1842   // Don't walk the arrays since they are walked from the ClassLoaderData objects.
  1845 #ifdef ASSERT
  1846 template <class T> void assert_is_in(T *p) {
  1847   T heap_oop = oopDesc::load_heap_oop(p);
  1848   if (!oopDesc::is_null(heap_oop)) {
  1849     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1850     assert(Universe::heap()->is_in(o), "should be in heap");
  1853 template <class T> void assert_is_in_closed_subset(T *p) {
  1854   T heap_oop = oopDesc::load_heap_oop(p);
  1855   if (!oopDesc::is_null(heap_oop)) {
  1856     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1857     assert(Universe::heap()->is_in_closed_subset(o),
  1858            err_msg("should be in closed *p " INTPTR_FORMAT " " INTPTR_FORMAT, (address)p, (address)o));
  1861 template <class T> void assert_is_in_reserved(T *p) {
  1862   T heap_oop = oopDesc::load_heap_oop(p);
  1863   if (!oopDesc::is_null(heap_oop)) {
  1864     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1865     assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
  1868 template <class T> void assert_nothing(T *p) {}
  1870 #else
  1871 template <class T> void assert_is_in(T *p) {}
  1872 template <class T> void assert_is_in_closed_subset(T *p) {}
  1873 template <class T> void assert_is_in_reserved(T *p) {}
  1874 template <class T> void assert_nothing(T *p) {}
  1875 #endif // ASSERT
  1877 //
  1878 // Macros that iterate over areas of oops which are specialized on type of
  1879 // oop pointer either narrow or wide, depending on UseCompressedOops
  1880 //
  1881 // Parameters are:
  1882 //   T         - type of oop to point to (either oop or narrowOop)
  1883 //   start_p   - starting pointer for region to iterate over
  1884 //   count     - number of oops or narrowOops to iterate over
  1885 //   do_oop    - action to perform on each oop (it's arbitrary C code which
  1886 //               makes it more efficient to put in a macro rather than making
  1887 //               it a template function)
  1888 //   assert_fn - assert function which is template function because performance
  1889 //               doesn't matter when enabled.
  1890 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
  1891   T, start_p, count, do_oop,                \
  1892   assert_fn)                                \
  1893 {                                           \
  1894   T* p         = (T*)(start_p);             \
  1895   T* const end = p + (count);               \
  1896   while (p < end) {                         \
  1897     (assert_fn)(p);                         \
  1898     do_oop;                                 \
  1899     ++p;                                    \
  1900   }                                         \
  1903 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
  1904   T, start_p, count, do_oop,                \
  1905   assert_fn)                                \
  1906 {                                           \
  1907   T* const start = (T*)(start_p);           \
  1908   T*       p     = start + (count);         \
  1909   while (start < p) {                       \
  1910     --p;                                    \
  1911     (assert_fn)(p);                         \
  1912     do_oop;                                 \
  1913   }                                         \
  1916 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
  1917   T, start_p, count, low, high,             \
  1918   do_oop, assert_fn)                        \
  1919 {                                           \
  1920   T* const l = (T*)(low);                   \
  1921   T* const h = (T*)(high);                  \
  1922   assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
  1923          mask_bits((intptr_t)h, sizeof(T)-1) == 0,   \
  1924          "bounded region must be properly aligned"); \
  1925   T* p       = (T*)(start_p);               \
  1926   T* end     = p + (count);                 \
  1927   if (p < l) p = l;                         \
  1928   if (end > h) end = h;                     \
  1929   while (p < end) {                         \
  1930     (assert_fn)(p);                         \
  1931     do_oop;                                 \
  1932     ++p;                                    \
  1933   }                                         \
  1937 // The following macros call specialized macros, passing either oop or
  1938 // narrowOop as the specialization type.  These test the UseCompressedOops
  1939 // flag.
  1940 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn)            \
  1941 {                                                                        \
  1942   /* Compute oopmap block range. The common case                         \
  1943      is nonstatic_oop_map_size == 1. */                                  \
  1944   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  1945   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
  1946   if (UseCompressedOops) {                                               \
  1947     while (map < end_map) {                                              \
  1948       InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop,                   \
  1949         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  1950         do_oop, assert_fn)                                               \
  1951       ++map;                                                             \
  1952     }                                                                    \
  1953   } else {                                                               \
  1954     while (map < end_map) {                                              \
  1955       InstanceKlass_SPECIALIZED_OOP_ITERATE(oop,                         \
  1956         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  1957         do_oop, assert_fn)                                               \
  1958       ++map;                                                             \
  1959     }                                                                    \
  1960   }                                                                      \
  1963 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn)    \
  1964 {                                                                        \
  1965   OopMapBlock* const start_map = start_of_nonstatic_oop_maps();          \
  1966   OopMapBlock* map             = start_map + nonstatic_oop_map_count();  \
  1967   if (UseCompressedOops) {                                               \
  1968     while (start_map < map) {                                            \
  1969       --map;                                                             \
  1970       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop,           \
  1971         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  1972         do_oop, assert_fn)                                               \
  1973     }                                                                    \
  1974   } else {                                                               \
  1975     while (start_map < map) {                                            \
  1976       --map;                                                             \
  1977       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop,                 \
  1978         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  1979         do_oop, assert_fn)                                               \
  1980     }                                                                    \
  1981   }                                                                      \
  1984 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop,    \
  1985                                               assert_fn)                 \
  1986 {                                                                        \
  1987   /* Compute oopmap block range. The common case is                      \
  1988      nonstatic_oop_map_size == 1, so we accept the                       \
  1989      usually non-existent extra overhead of examining                    \
  1990      all the maps. */                                                    \
  1991   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  1992   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
  1993   if (UseCompressedOops) {                                               \
  1994     while (map < end_map) {                                              \
  1995       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop,           \
  1996         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  1997         low, high,                                                       \
  1998         do_oop, assert_fn)                                               \
  1999       ++map;                                                             \
  2000     }                                                                    \
  2001   } else {                                                               \
  2002     while (map < end_map) {                                              \
  2003       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop,                 \
  2004         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  2005         low, high,                                                       \
  2006         do_oop, assert_fn)                                               \
  2007       ++map;                                                             \
  2008     }                                                                    \
  2009   }                                                                      \
  2012 void InstanceKlass::oop_follow_contents(oop obj) {
  2013   assert(obj != NULL, "can't follow the content of NULL object");
  2014   MarkSweep::follow_klass(obj->klass());
  2015   InstanceKlass_OOP_MAP_ITERATE( \
  2016     obj, \
  2017     MarkSweep::mark_and_push(p), \
  2018     assert_is_in_closed_subset)
  2021 #ifndef SERIALGC
  2022 void InstanceKlass::oop_follow_contents(ParCompactionManager* cm,
  2023                                         oop obj) {
  2024   assert(obj != NULL, "can't follow the content of NULL object");
  2025   PSParallelCompact::follow_klass(cm, obj->klass());
  2026   // Only mark the header and let the scan of the meta-data mark
  2027   // everything else.
  2028   InstanceKlass_OOP_MAP_ITERATE( \
  2029     obj, \
  2030     PSParallelCompact::mark_and_push(cm, p), \
  2031     assert_is_in)
  2033 #endif // SERIALGC
  2035 // closure's do_metadata() method dictates whether the given closure should be
  2036 // applied to the klass ptr in the object header.
  2038 #define if_do_metadata_checked(closure, nv_suffix)                    \
  2039   /* Make sure the non-virtual and the virtual versions match. */     \
  2040   assert(closure->do_metadata##nv_suffix() == closure->do_metadata(), \
  2041       "Inconsistency in do_metadata");                                \
  2042   if (closure->do_metadata##nv_suffix())
  2044 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)        \
  2046 int InstanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
  2047   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  2048   /* header */                                                          \
  2049   if_do_metadata_checked(closure, nv_suffix) {                          \
  2050     closure->do_klass##nv_suffix(obj->klass());                         \
  2051   }                                                                     \
  2052   InstanceKlass_OOP_MAP_ITERATE(                                        \
  2053     obj,                                                                \
  2054     SpecializationStats::                                               \
  2055       record_do_oop_call##nv_suffix(SpecializationStats::ik);           \
  2056     (closure)->do_oop##nv_suffix(p),                                    \
  2057     assert_is_in_closed_subset)                                         \
  2058   return size_helper();                                                 \
  2061 #ifndef SERIALGC
  2062 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
  2064 int InstanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj,                \
  2065                                               OopClosureType* closure) {        \
  2066   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
  2067   /* header */                                                                  \
  2068   if_do_metadata_checked(closure, nv_suffix) {                                  \
  2069     closure->do_klass##nv_suffix(obj->klass());                                 \
  2070   }                                                                             \
  2071   /* instance variables */                                                      \
  2072   InstanceKlass_OOP_MAP_REVERSE_ITERATE(                                        \
  2073     obj,                                                                        \
  2074     SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
  2075     (closure)->do_oop##nv_suffix(p),                                            \
  2076     assert_is_in_closed_subset)                                                 \
  2077    return size_helper();                                                        \
  2079 #endif // !SERIALGC
  2081 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
  2083 int InstanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj,              \
  2084                                                   OopClosureType* closure, \
  2085                                                   MemRegion mr) {          \
  2086   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  2087   if_do_metadata_checked(closure, nv_suffix) {                           \
  2088     if (mr.contains(obj)) {                                              \
  2089       closure->do_klass##nv_suffix(obj->klass());                        \
  2090     }                                                                    \
  2091   }                                                                      \
  2092   InstanceKlass_BOUNDED_OOP_MAP_ITERATE(                                 \
  2093     obj, mr.start(), mr.end(),                                           \
  2094     (closure)->do_oop##nv_suffix(p),                                     \
  2095     assert_is_in_closed_subset)                                          \
  2096   return size_helper();                                                  \
  2099 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
  2100 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
  2101 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
  2102 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
  2103 #ifndef SERIALGC
  2104 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
  2105 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
  2106 #endif // !SERIALGC
  2108 int InstanceKlass::oop_adjust_pointers(oop obj) {
  2109   int size = size_helper();
  2110   InstanceKlass_OOP_MAP_ITERATE( \
  2111     obj, \
  2112     MarkSweep::adjust_pointer(p), \
  2113     assert_is_in)
  2114   MarkSweep::adjust_klass(obj->klass());
  2115   return size;
  2118 #ifndef SERIALGC
  2119 void InstanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
  2120   InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
  2121     obj, \
  2122     if (PSScavenge::should_scavenge(p)) { \
  2123       pm->claim_or_forward_depth(p); \
  2124     }, \
  2125     assert_nothing )
  2128 int InstanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
  2129   int size = size_helper();
  2130   InstanceKlass_OOP_MAP_ITERATE( \
  2131     obj, \
  2132     PSParallelCompact::adjust_pointer(p), \
  2133     assert_is_in)
  2134   obj->update_header(cm);
  2135   return size;
  2138 #endif // SERIALGC
  2140 void InstanceKlass::clean_implementors_list(BoolObjectClosure* is_alive) {
  2141   assert(is_loader_alive(is_alive), "this klass should be live");
  2142   if (is_interface()) {
  2143     if (ClassUnloading) {
  2144       Klass* impl = implementor();
  2145       if (impl != NULL) {
  2146         if (!impl->is_loader_alive(is_alive)) {
  2147           // remove this guy
  2148           *adr_implementor() = NULL;
  2155 void InstanceKlass::clean_method_data(BoolObjectClosure* is_alive) {
  2156 #ifdef COMPILER2
  2157   // Currently only used by C2.
  2158   for (int m = 0; m < methods()->length(); m++) {
  2159     MethodData* mdo = methods()->at(m)->method_data();
  2160     if (mdo != NULL) {
  2161       for (ProfileData* data = mdo->first_data();
  2162            mdo->is_valid(data);
  2163            data = mdo->next_data(data)) {
  2164         data->clean_weak_klass_links(is_alive);
  2168 #else
  2169 #ifdef ASSERT
  2170   // Verify that we haven't started to use MDOs for C1.
  2171   for (int m = 0; m < methods()->length(); m++) {
  2172     MethodData* mdo = methods()->at(m)->method_data();
  2173     assert(mdo == NULL, "Didn't expect C1 to use MDOs");
  2175 #endif // ASSERT
  2176 #endif // !COMPILER2
  2180 static void remove_unshareable_in_class(Klass* k) {
  2181   // remove klass's unshareable info
  2182   k->remove_unshareable_info();
  2185 void InstanceKlass::remove_unshareable_info() {
  2186   Klass::remove_unshareable_info();
  2187   // Unlink the class
  2188   if (is_linked()) {
  2189     unlink_class();
  2191   init_implementor();
  2193   constants()->remove_unshareable_info();
  2195   for (int i = 0; i < methods()->length(); i++) {
  2196     Method* m = methods()->at(i);
  2197     m->remove_unshareable_info();
  2200   // Need to reinstate when reading back the class.
  2201   set_init_lock(NULL);
  2203   // do array classes also.
  2204   array_klasses_do(remove_unshareable_in_class);
  2207 void restore_unshareable_in_class(Klass* k, TRAPS) {
  2208   k->restore_unshareable_info(CHECK);
  2211 void InstanceKlass::restore_unshareable_info(TRAPS) {
  2212   Klass::restore_unshareable_info(CHECK);
  2213   instanceKlassHandle ik(THREAD, this);
  2215   Array<Method*>* methods = ik->methods();
  2216   int num_methods = methods->length();
  2217   for (int index2 = 0; index2 < num_methods; ++index2) {
  2218     methodHandle m(THREAD, methods->at(index2));
  2219     m()->link_method(m, CHECK);
  2220     // restore method's vtable by calling a virtual function
  2221     m->restore_vtable();
  2223   if (JvmtiExport::has_redefined_a_class()) {
  2224     // Reinitialize vtable because RedefineClasses may have changed some
  2225     // entries in this vtable for super classes so the CDS vtable might
  2226     // point to old or obsolete entries.  RedefineClasses doesn't fix up
  2227     // vtables in the shared system dictionary, only the main one.
  2228     // It also redefines the itable too so fix that too.
  2229     ResourceMark rm(THREAD);
  2230     ik->vtable()->initialize_vtable(false, CHECK);
  2231     ik->itable()->initialize_itable(false, CHECK);
  2234   // Allocate a simple java object for a lock.
  2235   // This needs to be a java object because during class initialization
  2236   // it can be held across a java call.
  2237   typeArrayOop r = oopFactory::new_typeArray(T_INT, 0, CHECK);
  2238   Handle h(THREAD, (oop)r);
  2239   ik->set_init_lock(h());
  2241   // restore constant pool resolved references
  2242   ik->constants()->restore_unshareable_info(CHECK);
  2244   ik->array_klasses_do(restore_unshareable_in_class, CHECK);
  2247 static void clear_all_breakpoints(Method* m) {
  2248   m->clear_all_breakpoints();
  2251 void InstanceKlass::release_C_heap_structures() {
  2252   // Deallocate oop map cache
  2253   if (_oop_map_cache != NULL) {
  2254     delete _oop_map_cache;
  2255     _oop_map_cache = NULL;
  2258   // Deallocate JNI identifiers for jfieldIDs
  2259   JNIid::deallocate(jni_ids());
  2260   set_jni_ids(NULL);
  2262   jmethodID* jmeths = methods_jmethod_ids_acquire();
  2263   if (jmeths != (jmethodID*)NULL) {
  2264     release_set_methods_jmethod_ids(NULL);
  2265     FreeHeap(jmeths);
  2268   int* indices = methods_cached_itable_indices_acquire();
  2269   if (indices != (int*)NULL) {
  2270     release_set_methods_cached_itable_indices(NULL);
  2271     FreeHeap(indices);
  2274   // release dependencies
  2275   nmethodBucket* b = _dependencies;
  2276   _dependencies = NULL;
  2277   while (b != NULL) {
  2278     nmethodBucket* next = b->next();
  2279     delete b;
  2280     b = next;
  2283   // Deallocate breakpoint records
  2284   if (breakpoints() != 0x0) {
  2285     methods_do(clear_all_breakpoints);
  2286     assert(breakpoints() == 0x0, "should have cleared breakpoints");
  2289   // deallocate information about previous versions
  2290   if (_previous_versions != NULL) {
  2291     for (int i = _previous_versions->length() - 1; i >= 0; i--) {
  2292       PreviousVersionNode * pv_node = _previous_versions->at(i);
  2293       delete pv_node;
  2295     delete _previous_versions;
  2296     _previous_versions = NULL;
  2299   // deallocate the cached class file
  2300   if (_cached_class_file_bytes != NULL) {
  2301     os::free(_cached_class_file_bytes, mtClass);
  2302     _cached_class_file_bytes = NULL;
  2303     _cached_class_file_len = 0;
  2306   // Decrement symbol reference counts associated with the unloaded class.
  2307   if (_name != NULL) _name->decrement_refcount();
  2308   // unreference array name derived from this class name (arrays of an unloaded
  2309   // class can't be referenced anymore).
  2310   if (_array_name != NULL)  _array_name->decrement_refcount();
  2311   if (_source_file_name != NULL) _source_file_name->decrement_refcount();
  2312   if (_source_debug_extension != NULL) FREE_C_HEAP_ARRAY(char, _source_debug_extension, mtClass);
  2315 void InstanceKlass::set_source_file_name(Symbol* n) {
  2316   _source_file_name = n;
  2317   if (_source_file_name != NULL) _source_file_name->increment_refcount();
  2320 void InstanceKlass::set_source_debug_extension(char* array, int length) {
  2321   if (array == NULL) {
  2322     _source_debug_extension = NULL;
  2323   } else {
  2324     // Adding one to the attribute length in order to store a null terminator
  2325     // character could cause an overflow because the attribute length is
  2326     // already coded with an u4 in the classfile, but in practice, it's
  2327     // unlikely to happen.
  2328     assert((length+1) > length, "Overflow checking");
  2329     char* sde = NEW_C_HEAP_ARRAY(char, (length + 1), mtClass);
  2330     for (int i = 0; i < length; i++) {
  2331       sde[i] = array[i];
  2333     sde[length] = '\0';
  2334     _source_debug_extension = sde;
  2338 address InstanceKlass::static_field_addr(int offset) {
  2339   return (address)(offset + InstanceMirrorKlass::offset_of_static_fields() + (intptr_t)java_mirror());
  2343 const char* InstanceKlass::signature_name() const {
  2344   const char* src = (const char*) (name()->as_C_string());
  2345   const int src_length = (int)strlen(src);
  2346   char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
  2347   int src_index = 0;
  2348   int dest_index = 0;
  2349   dest[dest_index++] = 'L';
  2350   while (src_index < src_length) {
  2351     dest[dest_index++] = src[src_index++];
  2353   dest[dest_index++] = ';';
  2354   dest[dest_index] = '\0';
  2355   return dest;
  2358 // different verisons of is_same_class_package
  2359 bool InstanceKlass::is_same_class_package(Klass* class2) {
  2360   Klass* class1 = this;
  2361   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
  2362   Symbol* classname1 = Klass::cast(class1)->name();
  2364   if (Klass::cast(class2)->oop_is_objArray()) {
  2365     class2 = ObjArrayKlass::cast(class2)->bottom_klass();
  2367   oop classloader2;
  2368   if (Klass::cast(class2)->oop_is_instance()) {
  2369     classloader2 = InstanceKlass::cast(class2)->class_loader();
  2370   } else {
  2371     assert(Klass::cast(class2)->oop_is_typeArray(), "should be type array");
  2372     classloader2 = NULL;
  2374   Symbol* classname2 = Klass::cast(class2)->name();
  2376   return InstanceKlass::is_same_class_package(classloader1, classname1,
  2377                                               classloader2, classname2);
  2380 bool InstanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
  2381   Klass* class1 = this;
  2382   oop classloader1 = InstanceKlass::cast(class1)->class_loader();
  2383   Symbol* classname1 = Klass::cast(class1)->name();
  2385   return InstanceKlass::is_same_class_package(classloader1, classname1,
  2386                                               classloader2, classname2);
  2389 // return true if two classes are in the same package, classloader
  2390 // and classname information is enough to determine a class's package
  2391 bool InstanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
  2392                                           oop class_loader2, Symbol* class_name2) {
  2393   if (class_loader1 != class_loader2) {
  2394     return false;
  2395   } else if (class_name1 == class_name2) {
  2396     return true;                // skip painful bytewise comparison
  2397   } else {
  2398     ResourceMark rm;
  2400     // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
  2401     // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
  2402     // Otherwise, we just compare jbyte values between the strings.
  2403     const jbyte *name1 = class_name1->base();
  2404     const jbyte *name2 = class_name2->base();
  2406     const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
  2407     const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
  2409     if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
  2410       // One of the two doesn't have a package.  Only return true
  2411       // if the other one also doesn't have a package.
  2412       return last_slash1 == last_slash2;
  2413     } else {
  2414       // Skip over '['s
  2415       if (*name1 == '[') {
  2416         do {
  2417           name1++;
  2418         } while (*name1 == '[');
  2419         if (*name1 != 'L') {
  2420           // Something is terribly wrong.  Shouldn't be here.
  2421           return false;
  2424       if (*name2 == '[') {
  2425         do {
  2426           name2++;
  2427         } while (*name2 == '[');
  2428         if (*name2 != 'L') {
  2429           // Something is terribly wrong.  Shouldn't be here.
  2430           return false;
  2434       // Check that package part is identical
  2435       int length1 = last_slash1 - name1;
  2436       int length2 = last_slash2 - name2;
  2438       return UTF8::equal(name1, length1, name2, length2);
  2443 // Returns true iff super_method can be overridden by a method in targetclassname
  2444 // See JSL 3rd edition 8.4.6.1
  2445 // Assumes name-signature match
  2446 // "this" is InstanceKlass of super_method which must exist
  2447 // note that the InstanceKlass of the method in the targetclassname has not always been created yet
  2448 bool InstanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
  2449    // Private methods can not be overridden
  2450    if (super_method->is_private()) {
  2451      return false;
  2453    // If super method is accessible, then override
  2454    if ((super_method->is_protected()) ||
  2455        (super_method->is_public())) {
  2456      return true;
  2458    // Package-private methods are not inherited outside of package
  2459    assert(super_method->is_package_private(), "must be package private");
  2460    return(is_same_class_package(targetclassloader(), targetclassname));
  2463 /* defined for now in jvm.cpp, for historical reasons *--
  2464 Klass* InstanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
  2465                                                      Symbol*& simple_name_result, TRAPS) {
  2466   ...
  2468 */
  2470 // tell if two classes have the same enclosing class (at package level)
  2471 bool InstanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
  2472                                                 Klass* class2_oop, TRAPS) {
  2473   if (class2_oop == class1())                       return true;
  2474   if (!Klass::cast(class2_oop)->oop_is_instance())  return false;
  2475   instanceKlassHandle class2(THREAD, class2_oop);
  2477   // must be in same package before we try anything else
  2478   if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
  2479     return false;
  2481   // As long as there is an outer1.getEnclosingClass,
  2482   // shift the search outward.
  2483   instanceKlassHandle outer1 = class1;
  2484   for (;;) {
  2485     // As we walk along, look for equalities between outer1 and class2.
  2486     // Eventually, the walks will terminate as outer1 stops
  2487     // at the top-level class around the original class.
  2488     bool ignore_inner_is_member;
  2489     Klass* next = outer1->compute_enclosing_class(&ignore_inner_is_member,
  2490                                                     CHECK_false);
  2491     if (next == NULL)  break;
  2492     if (next == class2())  return true;
  2493     outer1 = instanceKlassHandle(THREAD, next);
  2496   // Now do the same for class2.
  2497   instanceKlassHandle outer2 = class2;
  2498   for (;;) {
  2499     bool ignore_inner_is_member;
  2500     Klass* next = outer2->compute_enclosing_class(&ignore_inner_is_member,
  2501                                                     CHECK_false);
  2502     if (next == NULL)  break;
  2503     // Might as well check the new outer against all available values.
  2504     if (next == class1())  return true;
  2505     if (next == outer1())  return true;
  2506     outer2 = instanceKlassHandle(THREAD, next);
  2509   // If by this point we have not found an equality between the
  2510   // two classes, we know they are in separate package members.
  2511   return false;
  2515 jint InstanceKlass::compute_modifier_flags(TRAPS) const {
  2516   jint access = access_flags().as_int();
  2518   // But check if it happens to be member class.
  2519   instanceKlassHandle ik(THREAD, this);
  2520   InnerClassesIterator iter(ik);
  2521   for (; !iter.done(); iter.next()) {
  2522     int ioff = iter.inner_class_info_index();
  2523     // Inner class attribute can be zero, skip it.
  2524     // Strange but true:  JVM spec. allows null inner class refs.
  2525     if (ioff == 0) continue;
  2527     // only look at classes that are already loaded
  2528     // since we are looking for the flags for our self.
  2529     Symbol* inner_name = ik->constants()->klass_name_at(ioff);
  2530     if ((ik->name() == inner_name)) {
  2531       // This is really a member class.
  2532       access = iter.inner_access_flags();
  2533       break;
  2536   // Remember to strip ACC_SUPER bit
  2537   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
  2540 jint InstanceKlass::jvmti_class_status() const {
  2541   jint result = 0;
  2543   if (is_linked()) {
  2544     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
  2547   if (is_initialized()) {
  2548     assert(is_linked(), "Class status is not consistent");
  2549     result |= JVMTI_CLASS_STATUS_INITIALIZED;
  2551   if (is_in_error_state()) {
  2552     result |= JVMTI_CLASS_STATUS_ERROR;
  2554   return result;
  2557 Method* InstanceKlass::method_at_itable(Klass* holder, int index, TRAPS) {
  2558   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
  2559   int method_table_offset_in_words = ioe->offset()/wordSize;
  2560   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
  2561                        / itableOffsetEntry::size();
  2563   for (int cnt = 0 ; ; cnt ++, ioe ++) {
  2564     // If the interface isn't implemented by the receiver class,
  2565     // the VM should throw IncompatibleClassChangeError.
  2566     if (cnt >= nof_interfaces) {
  2567       THROW_NULL(vmSymbols::java_lang_IncompatibleClassChangeError());
  2570     Klass* ik = ioe->interface_klass();
  2571     if (ik == holder) break;
  2574   itableMethodEntry* ime = ioe->first_method_entry(this);
  2575   Method* m = ime[index].method();
  2576   if (m == NULL) {
  2577     THROW_NULL(vmSymbols::java_lang_AbstractMethodError());
  2579   return m;
  2582 // On-stack replacement stuff
  2583 void InstanceKlass::add_osr_nmethod(nmethod* n) {
  2584   // only one compilation can be active
  2585   NEEDS_CLEANUP
  2586   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2587   OsrList_lock->lock_without_safepoint_check();
  2588   assert(n->is_osr_method(), "wrong kind of nmethod");
  2589   n->set_osr_link(osr_nmethods_head());
  2590   set_osr_nmethods_head(n);
  2591   // Raise the highest osr level if necessary
  2592   if (TieredCompilation) {
  2593     Method* m = n->method();
  2594     m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
  2596   // Remember to unlock again
  2597   OsrList_lock->unlock();
  2599   // Get rid of the osr methods for the same bci that have lower levels.
  2600   if (TieredCompilation) {
  2601     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
  2602       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
  2603       if (inv != NULL && inv->is_in_use()) {
  2604         inv->make_not_entrant();
  2611 void InstanceKlass::remove_osr_nmethod(nmethod* n) {
  2612   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2613   OsrList_lock->lock_without_safepoint_check();
  2614   assert(n->is_osr_method(), "wrong kind of nmethod");
  2615   nmethod* last = NULL;
  2616   nmethod* cur  = osr_nmethods_head();
  2617   int max_level = CompLevel_none;  // Find the max comp level excluding n
  2618   Method* m = n->method();
  2619   // Search for match
  2620   while(cur != NULL && cur != n) {
  2621     if (TieredCompilation) {
  2622       // Find max level before n
  2623       max_level = MAX2(max_level, cur->comp_level());
  2625     last = cur;
  2626     cur = cur->osr_link();
  2628   nmethod* next = NULL;
  2629   if (cur == n) {
  2630     next = cur->osr_link();
  2631     if (last == NULL) {
  2632       // Remove first element
  2633       set_osr_nmethods_head(next);
  2634     } else {
  2635       last->set_osr_link(next);
  2638   n->set_osr_link(NULL);
  2639   if (TieredCompilation) {
  2640     cur = next;
  2641     while (cur != NULL) {
  2642       // Find max level after n
  2643       max_level = MAX2(max_level, cur->comp_level());
  2644       cur = cur->osr_link();
  2646     m->set_highest_osr_comp_level(max_level);
  2648   // Remember to unlock again
  2649   OsrList_lock->unlock();
  2652 nmethod* InstanceKlass::lookup_osr_nmethod(Method* const m, int bci, int comp_level, bool match_level) const {
  2653   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2654   OsrList_lock->lock_without_safepoint_check();
  2655   nmethod* osr = osr_nmethods_head();
  2656   nmethod* best = NULL;
  2657   while (osr != NULL) {
  2658     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
  2659     // There can be a time when a c1 osr method exists but we are waiting
  2660     // for a c2 version. When c2 completes its osr nmethod we will trash
  2661     // the c1 version and only be able to find the c2 version. However
  2662     // while we overflow in the c1 code at back branches we don't want to
  2663     // try and switch to the same code as we are already running
  2665     if (osr->method() == m &&
  2666         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
  2667       if (match_level) {
  2668         if (osr->comp_level() == comp_level) {
  2669           // Found a match - return it.
  2670           OsrList_lock->unlock();
  2671           return osr;
  2673       } else {
  2674         if (best == NULL || (osr->comp_level() > best->comp_level())) {
  2675           if (osr->comp_level() == CompLevel_highest_tier) {
  2676             // Found the best possible - return it.
  2677             OsrList_lock->unlock();
  2678             return osr;
  2680           best = osr;
  2684     osr = osr->osr_link();
  2686   OsrList_lock->unlock();
  2687   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
  2688     return best;
  2690   return NULL;
  2693 // -----------------------------------------------------------------------------------------------------
  2694 // Printing
  2696 #ifndef PRODUCT
  2698 #define BULLET  " - "
  2700 static const char* state_names[] = {
  2701   "allocated", "loaded", "linked", "being_initialized", "fully_initialized", "initialization_error"
  2702 };
  2704 void InstanceKlass::print_on(outputStream* st) const {
  2705   assert(is_klass(), "must be klass");
  2706   Klass::print_on(st);
  2708   st->print(BULLET"instance size:     %d", size_helper());                        st->cr();
  2709   st->print(BULLET"klass size:        %d", size());                               st->cr();
  2710   st->print(BULLET"access:            "); access_flags().print_on(st);            st->cr();
  2711   st->print(BULLET"state:             "); st->print_cr(state_names[_init_state]);
  2712   st->print(BULLET"name:              "); name()->print_value_on(st);             st->cr();
  2713   st->print(BULLET"super:             "); super()->print_value_on_maybe_null(st); st->cr();
  2714   st->print(BULLET"sub:               ");
  2715   Klass* sub = subklass();
  2716   int n;
  2717   for (n = 0; sub != NULL; n++, sub = sub->next_sibling()) {
  2718     if (n < MaxSubklassPrintSize) {
  2719       sub->print_value_on(st);
  2720       st->print("   ");
  2723   if (n >= MaxSubklassPrintSize) st->print("(%d more klasses...)", n - MaxSubklassPrintSize);
  2724   st->cr();
  2726   if (is_interface()) {
  2727     st->print_cr(BULLET"nof implementors:  %d", nof_implementors());
  2728     if (nof_implementors() == 1) {
  2729       st->print_cr(BULLET"implementor:    ");
  2730       st->print("   ");
  2731       implementor()->print_value_on(st);
  2732       st->cr();
  2736   st->print(BULLET"arrays:            "); array_klasses()->print_value_on_maybe_null(st); st->cr();
  2737   st->print(BULLET"methods:           "); methods()->print_value_on(st);                  st->cr();
  2738   if (Verbose) {
  2739     Array<Method*>* method_array = methods();
  2740     for(int i = 0; i < method_array->length(); i++) {
  2741       st->print("%d : ", i); method_array->at(i)->print_value(); st->cr();
  2744   st->print(BULLET"method ordering:   "); method_ordering()->print_value_on(st);       st->cr();
  2745   st->print(BULLET"local interfaces:  "); local_interfaces()->print_value_on(st);      st->cr();
  2746   st->print(BULLET"trans. interfaces: "); transitive_interfaces()->print_value_on(st); st->cr();
  2747   st->print(BULLET"constants:         "); constants()->print_value_on(st);         st->cr();
  2748   if (class_loader_data() != NULL) {
  2749     st->print(BULLET"class loader data:  ");
  2750     class_loader_data()->print_value_on(st);
  2751     st->cr();
  2753   st->print(BULLET"protection domain: "); ((InstanceKlass*)this)->protection_domain()->print_value_on(st); st->cr();
  2754   st->print(BULLET"host class:        "); host_klass()->print_value_on_maybe_null(st); st->cr();
  2755   st->print(BULLET"signers:           "); signers()->print_value_on(st);               st->cr();
  2756   st->print(BULLET"init_lock:         "); ((oop)init_lock())->print_value_on(st);             st->cr();
  2757   if (source_file_name() != NULL) {
  2758     st->print(BULLET"source file:       ");
  2759     source_file_name()->print_value_on(st);
  2760     st->cr();
  2762   if (source_debug_extension() != NULL) {
  2763     st->print(BULLET"source debug extension:       ");
  2764     st->print("%s", source_debug_extension());
  2765     st->cr();
  2767   st->print(BULLET"annotations:       "); annotations()->print_value_on(st); st->cr();
  2769     ResourceMark rm;
  2770     // PreviousVersionInfo objects returned via PreviousVersionWalker
  2771     // contain a GrowableArray of handles. We have to clean up the
  2772     // GrowableArray _after_ the PreviousVersionWalker destructor
  2773     // has destroyed the handles.
  2775       bool have_pv = false;
  2776       PreviousVersionWalker pvw((InstanceKlass*)this);
  2777       for (PreviousVersionInfo * pv_info = pvw.next_previous_version();
  2778            pv_info != NULL; pv_info = pvw.next_previous_version()) {
  2779         if (!have_pv)
  2780           st->print(BULLET"previous version:  ");
  2781         have_pv = true;
  2782         pv_info->prev_constant_pool_handle()()->print_value_on(st);
  2784       if (have_pv)  st->cr();
  2785     } // pvw is cleaned up
  2786   } // rm is cleaned up
  2788   if (generic_signature() != NULL) {
  2789     st->print(BULLET"generic signature: ");
  2790     generic_signature()->print_value_on(st);
  2791     st->cr();
  2793   st->print(BULLET"inner classes:     "); inner_classes()->print_value_on(st);     st->cr();
  2794   st->print(BULLET"java mirror:       "); java_mirror()->print_value_on(st);       st->cr();
  2795   st->print(BULLET"vtable length      %d  (start addr: " INTPTR_FORMAT ")", vtable_length(), start_of_vtable());  st->cr();
  2796   st->print(BULLET"itable length      %d (start addr: " INTPTR_FORMAT ")", itable_length(), start_of_itable()); st->cr();
  2797   st->print_cr(BULLET"---- static fields (%d words):", static_field_size());
  2798   FieldPrinter print_static_field(st);
  2799   ((InstanceKlass*)this)->do_local_static_fields(&print_static_field);
  2800   st->print_cr(BULLET"---- non-static fields (%d words):", nonstatic_field_size());
  2801   FieldPrinter print_nonstatic_field(st);
  2802   ((InstanceKlass*)this)->do_nonstatic_fields(&print_nonstatic_field);
  2804   st->print(BULLET"non-static oop maps: ");
  2805   OopMapBlock* map     = start_of_nonstatic_oop_maps();
  2806   OopMapBlock* end_map = map + nonstatic_oop_map_count();
  2807   while (map < end_map) {
  2808     st->print("%d-%d ", map->offset(), map->offset() + heapOopSize*(map->count() - 1));
  2809     map++;
  2811   st->cr();
  2814 #endif //PRODUCT
  2816 void InstanceKlass::print_value_on(outputStream* st) const {
  2817   assert(is_klass(), "must be klass");
  2818   name()->print_value_on(st);
  2821 #ifndef PRODUCT
  2823 void FieldPrinter::do_field(fieldDescriptor* fd) {
  2824   _st->print(BULLET);
  2825    if (_obj == NULL) {
  2826      fd->print_on(_st);
  2827      _st->cr();
  2828    } else {
  2829      fd->print_on_for(_st, _obj);
  2830      _st->cr();
  2835 void InstanceKlass::oop_print_on(oop obj, outputStream* st) {
  2836   Klass::oop_print_on(obj, st);
  2838   if (this == SystemDictionary::String_klass()) {
  2839     typeArrayOop value  = java_lang_String::value(obj);
  2840     juint        offset = java_lang_String::offset(obj);
  2841     juint        length = java_lang_String::length(obj);
  2842     if (value != NULL &&
  2843         value->is_typeArray() &&
  2844         offset          <= (juint) value->length() &&
  2845         offset + length <= (juint) value->length()) {
  2846       st->print(BULLET"string: ");
  2847       Handle h_obj(obj);
  2848       java_lang_String::print(h_obj, st);
  2849       st->cr();
  2850       if (!WizardMode)  return;  // that is enough
  2854   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
  2855   FieldPrinter print_field(st, obj);
  2856   do_nonstatic_fields(&print_field);
  2858   if (this == SystemDictionary::Class_klass()) {
  2859     st->print(BULLET"signature: ");
  2860     java_lang_Class::print_signature(obj, st);
  2861     st->cr();
  2862     Klass* mirrored_klass = java_lang_Class::as_Klass(obj);
  2863     st->print(BULLET"fake entry for mirror: ");
  2864     mirrored_klass->print_value_on_maybe_null(st);
  2865     st->cr();
  2866     st->print(BULLET"fake entry resolved_constructor: ");
  2867     Method* ctor = java_lang_Class::resolved_constructor(obj);
  2868     ctor->print_value_on_maybe_null(st);
  2869     Klass* array_klass = java_lang_Class::array_klass(obj);
  2870     st->cr();
  2871     st->print(BULLET"fake entry for array: ");
  2872     array_klass->print_value_on_maybe_null(st);
  2873     st->cr();
  2874     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
  2875     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
  2876     Klass* real_klass = java_lang_Class::as_Klass(obj);
  2877     if (real_klass != NULL && real_klass->oop_is_instance()) {
  2878       InstanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
  2880   } else if (this == SystemDictionary::MethodType_klass()) {
  2881     st->print(BULLET"signature: ");
  2882     java_lang_invoke_MethodType::print_signature(obj, st);
  2883     st->cr();
  2887 #endif //PRODUCT
  2889 void InstanceKlass::oop_print_value_on(oop obj, outputStream* st) {
  2890   st->print("a ");
  2891   name()->print_value_on(st);
  2892   obj->print_address_on(st);
  2893   if (this == SystemDictionary::String_klass()
  2894       && java_lang_String::value(obj) != NULL) {
  2895     ResourceMark rm;
  2896     int len = java_lang_String::length(obj);
  2897     int plen = (len < 24 ? len : 12);
  2898     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
  2899     st->print(" = \"%s\"", str);
  2900     if (len > plen)
  2901       st->print("...[%d]", len);
  2902   } else if (this == SystemDictionary::Class_klass()) {
  2903     Klass* k = java_lang_Class::as_Klass(obj);
  2904     st->print(" = ");
  2905     if (k != NULL) {
  2906       k->print_value_on(st);
  2907     } else {
  2908       const char* tname = type2name(java_lang_Class::primitive_type(obj));
  2909       st->print("%s", tname ? tname : "type?");
  2911   } else if (this == SystemDictionary::MethodType_klass()) {
  2912     st->print(" = ");
  2913     java_lang_invoke_MethodType::print_signature(obj, st);
  2914   } else if (java_lang_boxing_object::is_instance(obj)) {
  2915     st->print(" = ");
  2916     java_lang_boxing_object::print(obj, st);
  2917   } else if (this == SystemDictionary::LambdaForm_klass()) {
  2918     oop vmentry = java_lang_invoke_LambdaForm::vmentry(obj);
  2919     if (vmentry != NULL) {
  2920       st->print(" => ");
  2921       vmentry->print_value_on(st);
  2923   } else if (this == SystemDictionary::MemberName_klass()) {
  2924     Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(obj);
  2925     if (vmtarget != NULL) {
  2926       st->print(" = ");
  2927       vmtarget->print_value_on(st);
  2928     } else {
  2929       java_lang_invoke_MemberName::clazz(obj)->print_value_on(st);
  2930       st->print(".");
  2931       java_lang_invoke_MemberName::name(obj)->print_value_on(st);
  2936 const char* InstanceKlass::internal_name() const {
  2937   return external_name();
  2940 // Verification
  2942 class VerifyFieldClosure: public OopClosure {
  2943  protected:
  2944   template <class T> void do_oop_work(T* p) {
  2945     oop obj = oopDesc::load_decode_heap_oop(p);
  2946     if (!obj->is_oop_or_null()) {
  2947       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
  2948       Universe::print();
  2949       guarantee(false, "boom");
  2952  public:
  2953   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
  2954   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
  2955 };
  2957 void InstanceKlass::verify_on(outputStream* st) {
  2958   Klass::verify_on(st);
  2959   Thread *thread = Thread::current();
  2961 #ifndef PRODUCT
  2962   // Avoid redundant verifies
  2963   if (_verify_count == Universe::verify_count()) return;
  2964   _verify_count = Universe::verify_count();
  2965 #endif
  2966   // Verify that klass is present in SystemDictionary
  2967   if (is_loaded() && !is_anonymous()) {
  2968     Symbol* h_name = name();
  2969     SystemDictionary::verify_obj_klass_present(h_name, class_loader_data());
  2972   // Verify static fields
  2973   VerifyFieldClosure blk;
  2975   // Verify vtables
  2976   if (is_linked()) {
  2977     ResourceMark rm(thread);
  2978     // $$$ This used to be done only for m/s collections.  Doing it
  2979     // always seemed a valid generalization.  (DLD -- 6/00)
  2980     vtable()->verify(st);
  2983   // Verify first subklass
  2984   if (subklass_oop() != NULL) {
  2985     guarantee(subklass_oop()->is_metadata(), "should be in metaspace");
  2986     guarantee(subklass_oop()->is_klass(), "should be klass");
  2989   // Verify siblings
  2990   Klass* super = this->super();
  2991   Klass* sib = next_sibling();
  2992   if (sib != NULL) {
  2993     if (sib == this) {
  2994       fatal(err_msg("subclass points to itself " PTR_FORMAT, sib));
  2997     guarantee(sib->is_metadata(), "should be in metaspace");
  2998     guarantee(sib->is_klass(), "should be klass");
  2999     guarantee(sib->super() == super, "siblings should have same superklass");
  3002   // Verify implementor fields
  3003   Klass* im = implementor();
  3004   if (im != NULL) {
  3005     guarantee(is_interface(), "only interfaces should have implementor set");
  3006     guarantee(im->is_klass(), "should be klass");
  3007     guarantee(!Klass::cast(im)->is_interface() || im == this,
  3008       "implementors cannot be interfaces");
  3011   // Verify local interfaces
  3012   if (local_interfaces()) {
  3013     Array<Klass*>* local_interfaces = this->local_interfaces();
  3014     for (int j = 0; j < local_interfaces->length(); j++) {
  3015       Klass* e = local_interfaces->at(j);
  3016       guarantee(e->is_klass() && Klass::cast(e)->is_interface(), "invalid local interface");
  3020   // Verify transitive interfaces
  3021   if (transitive_interfaces() != NULL) {
  3022     Array<Klass*>* transitive_interfaces = this->transitive_interfaces();
  3023     for (int j = 0; j < transitive_interfaces->length(); j++) {
  3024       Klass* e = transitive_interfaces->at(j);
  3025       guarantee(e->is_klass() && Klass::cast(e)->is_interface(), "invalid transitive interface");
  3029   // Verify methods
  3030   if (methods() != NULL) {
  3031     Array<Method*>* methods = this->methods();
  3032     for (int j = 0; j < methods->length(); j++) {
  3033       guarantee(methods->at(j)->is_metadata(), "should be in metaspace");
  3034       guarantee(methods->at(j)->is_method(), "non-method in methods array");
  3036     for (int j = 0; j < methods->length() - 1; j++) {
  3037       Method* m1 = methods->at(j);
  3038       Method* m2 = methods->at(j + 1);
  3039       guarantee(m1->name()->fast_compare(m2->name()) <= 0, "methods not sorted correctly");
  3043   // Verify method ordering
  3044   if (method_ordering() != NULL) {
  3045     Array<int>* method_ordering = this->method_ordering();
  3046     int length = method_ordering->length();
  3047     if (JvmtiExport::can_maintain_original_method_order() ||
  3048         (UseSharedSpaces && length != 0)) {
  3049       guarantee(length == methods()->length(), "invalid method ordering length");
  3050       jlong sum = 0;
  3051       for (int j = 0; j < length; j++) {
  3052         int original_index = method_ordering->at(j);
  3053         guarantee(original_index >= 0, "invalid method ordering index");
  3054         guarantee(original_index < length, "invalid method ordering index");
  3055         sum += original_index;
  3057       // Verify sum of indices 0,1,...,length-1
  3058       guarantee(sum == ((jlong)length*(length-1))/2, "invalid method ordering sum");
  3059     } else {
  3060       guarantee(length == 0, "invalid method ordering length");
  3064   // Verify JNI static field identifiers
  3065   if (jni_ids() != NULL) {
  3066     jni_ids()->verify(this);
  3069   // Verify other fields
  3070   if (array_klasses() != NULL) {
  3071     guarantee(array_klasses()->is_metadata(), "should be in metaspace");
  3072     guarantee(array_klasses()->is_klass(), "should be klass");
  3074   if (constants() != NULL) {
  3075     guarantee(constants()->is_metadata(), "should be in metaspace");
  3076     guarantee(constants()->is_constantPool(), "should be constant pool");
  3078   if (protection_domain() != NULL) {
  3079     guarantee(protection_domain()->is_oop(), "should be oop");
  3081   if (host_klass() != NULL) {
  3082     guarantee(host_klass()->is_metadata(), "should be in metaspace");
  3083     guarantee(host_klass()->is_klass(), "should be klass");
  3085   if (signers() != NULL) {
  3086     guarantee(signers()->is_objArray(), "should be obj array");
  3090 void InstanceKlass::oop_verify_on(oop obj, outputStream* st) {
  3091   Klass::oop_verify_on(obj, st);
  3092   VerifyFieldClosure blk;
  3093   obj->oop_iterate_no_header(&blk);
  3097 // JNIid class for jfieldIDs only
  3098 // Note to reviewers:
  3099 // These JNI functions are just moved over to column 1 and not changed
  3100 // in the compressed oops workspace.
  3101 JNIid::JNIid(Klass* holder, int offset, JNIid* next) {
  3102   _holder = holder;
  3103   _offset = offset;
  3104   _next = next;
  3105   debug_only(_is_static_field_id = false;)
  3109 JNIid* JNIid::find(int offset) {
  3110   JNIid* current = this;
  3111   while (current != NULL) {
  3112     if (current->offset() == offset) return current;
  3113     current = current->next();
  3115   return NULL;
  3118 void JNIid::deallocate(JNIid* current) {
  3119   while (current != NULL) {
  3120     JNIid* next = current->next();
  3121     delete current;
  3122     current = next;
  3127 void JNIid::verify(Klass* holder) {
  3128   int first_field_offset  = InstanceMirrorKlass::offset_of_static_fields();
  3129   int end_field_offset;
  3130   end_field_offset = first_field_offset + (InstanceKlass::cast(holder)->static_field_size() * wordSize);
  3132   JNIid* current = this;
  3133   while (current != NULL) {
  3134     guarantee(current->holder() == holder, "Invalid klass in JNIid");
  3135 #ifdef ASSERT
  3136     int o = current->offset();
  3137     if (current->is_static_field_id()) {
  3138       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
  3140 #endif
  3141     current = current->next();
  3146 #ifdef ASSERT
  3147 void InstanceKlass::set_init_state(ClassState state) {
  3148   bool good_state = is_shared() ? (_init_state <= state)
  3149                                                : (_init_state < state);
  3150   assert(good_state || state == allocated, "illegal state transition");
  3151   _init_state = (u1)state;
  3153 #endif
  3156 // RedefineClasses() support for previous versions:
  3158 // Purge previous versions
  3159 static void purge_previous_versions_internal(InstanceKlass* ik, int emcp_method_count) {
  3160   if (ik->previous_versions() != NULL) {
  3161     // This klass has previous versions so see what we can cleanup
  3162     // while it is safe to do so.
  3164     int deleted_count = 0;    // leave debugging breadcrumbs
  3165     int live_count = 0;
  3166     ClassLoaderData* loader_data = ik->class_loader_data() == NULL ?
  3167                        ClassLoaderData::the_null_class_loader_data() :
  3168                        ik->class_loader_data();
  3170     // RC_TRACE macro has an embedded ResourceMark
  3171     RC_TRACE(0x00000200, ("purge: %s: previous version length=%d",
  3172       ik->external_name(), ik->previous_versions()->length()));
  3174     for (int i = ik->previous_versions()->length() - 1; i >= 0; i--) {
  3175       // check the previous versions array
  3176       PreviousVersionNode * pv_node = ik->previous_versions()->at(i);
  3177       ConstantPool* cp_ref = pv_node->prev_constant_pool();
  3178       assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
  3180       ConstantPool* pvcp = cp_ref;
  3181       if (!pvcp->on_stack()) {
  3182         // If the constant pool isn't on stack, none of the methods
  3183         // are executing.  Delete all the methods, the constant pool and
  3184         // and this previous version node.
  3185         GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3186         if (method_refs != NULL) {
  3187           for (int j = method_refs->length() - 1; j >= 0; j--) {
  3188             Method* method = method_refs->at(j);
  3189             assert(method != NULL, "method ref was unexpectedly cleared");
  3190             method_refs->remove_at(j);
  3191             // method will be freed with associated class.
  3194         // Remove the constant pool
  3195         delete pv_node;
  3196         // Since we are traversing the array backwards, we don't have to
  3197         // do anything special with the index.
  3198         ik->previous_versions()->remove_at(i);
  3199         deleted_count++;
  3200         continue;
  3201       } else {
  3202         RC_TRACE(0x00000200, ("purge: previous version @%d is alive", i));
  3203         assert(pvcp->pool_holder() != NULL, "Constant pool with no holder");
  3204         guarantee (!loader_data->is_unloading(), "unloaded classes can't be on the stack");
  3205         live_count++;
  3208       // At least one method is live in this previous version, clean out
  3209       // the others or mark them as obsolete.
  3210       GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3211       if (method_refs != NULL) {
  3212         RC_TRACE(0x00000200, ("purge: previous methods length=%d",
  3213           method_refs->length()));
  3214         for (int j = method_refs->length() - 1; j >= 0; j--) {
  3215           Method* method = method_refs->at(j);
  3216           assert(method != NULL, "method ref was unexpectedly cleared");
  3218           // Remove the emcp method if it's not executing
  3219           // If it's been made obsolete by a redefinition of a non-emcp
  3220           // method, mark it as obsolete but leave it to clean up later.
  3221           if (!method->on_stack()) {
  3222             method_refs->remove_at(j);
  3223           } else if (emcp_method_count == 0) {
  3224             method->set_is_obsolete();
  3225           } else {
  3226             // RC_TRACE macro has an embedded ResourceMark
  3227             RC_TRACE(0x00000200,
  3228               ("purge: %s(%s): prev method @%d in version @%d is alive",
  3229               method->name()->as_C_string(),
  3230               method->signature()->as_C_string(), j, i));
  3235     assert(ik->previous_versions()->length() == live_count, "sanity check");
  3236     RC_TRACE(0x00000200,
  3237       ("purge: previous version stats: live=%d, deleted=%d", live_count,
  3238       deleted_count));
  3242 // External interface for use during class unloading.
  3243 void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
  3244   // Call with >0 emcp methods since they are not currently being redefined.
  3245   purge_previous_versions_internal(ik, 1);
  3249 // Potentially add an information node that contains pointers to the
  3250 // interesting parts of the previous version of the_class.
  3251 // This is also where we clean out any unused references.
  3252 // Note that while we delete nodes from the _previous_versions
  3253 // array, we never delete the array itself until the klass is
  3254 // unloaded. The has_been_redefined() query depends on that fact.
  3255 //
  3256 void InstanceKlass::add_previous_version(instanceKlassHandle ikh,
  3257        BitMap* emcp_methods, int emcp_method_count) {
  3258   assert(Thread::current()->is_VM_thread(),
  3259          "only VMThread can add previous versions");
  3261   if (_previous_versions == NULL) {
  3262     // This is the first previous version so make some space.
  3263     // Start with 2 elements under the assumption that the class
  3264     // won't be redefined much.
  3265     _previous_versions =  new (ResourceObj::C_HEAP, mtClass)
  3266                             GrowableArray<PreviousVersionNode *>(2, true);
  3269   ConstantPool* cp_ref = ikh->constants();
  3271   // RC_TRACE macro has an embedded ResourceMark
  3272   RC_TRACE(0x00000400, ("adding previous version ref for %s @%d, EMCP_cnt=%d "
  3273                         "on_stack=%d",
  3274     ikh->external_name(), _previous_versions->length(), emcp_method_count,
  3275     cp_ref->on_stack()));
  3277   // If the constant pool for this previous version of the class
  3278   // is not marked as being on the stack, then none of the methods
  3279   // in this previous version of the class are on the stack so
  3280   // we don't need to create a new PreviousVersionNode. However,
  3281   // we still need to examine older previous versions below.
  3282   Array<Method*>* old_methods = ikh->methods();
  3284   if (cp_ref->on_stack()) {
  3285   PreviousVersionNode * pv_node = NULL;
  3286   if (emcp_method_count == 0) {
  3287       // non-shared ConstantPool gets a reference
  3288       pv_node = new PreviousVersionNode(cp_ref, !cp_ref->is_shared(), NULL);
  3289     RC_TRACE(0x00000400,
  3290         ("add: all methods are obsolete; flushing any EMCP refs"));
  3291   } else {
  3292     int local_count = 0;
  3293       GrowableArray<Method*>* method_refs = new (ResourceObj::C_HEAP, mtClass)
  3294         GrowableArray<Method*>(emcp_method_count, true);
  3295     for (int i = 0; i < old_methods->length(); i++) {
  3296       if (emcp_methods->at(i)) {
  3297           // this old method is EMCP. Save it only if it's on the stack
  3298           Method* old_method = old_methods->at(i);
  3299           if (old_method->on_stack()) {
  3300             method_refs->append(old_method);
  3302         if (++local_count >= emcp_method_count) {
  3303           // no more EMCP methods so bail out now
  3304           break;
  3308       // non-shared ConstantPool gets a reference
  3309       pv_node = new PreviousVersionNode(cp_ref, !cp_ref->is_shared(), method_refs);
  3311     // append new previous version.
  3312   _previous_versions->append(pv_node);
  3315   // Since the caller is the VMThread and we are at a safepoint, this
  3316   // is a good time to clear out unused references.
  3318   RC_TRACE(0x00000400, ("add: previous version length=%d",
  3319     _previous_versions->length()));
  3321   // Purge previous versions not executing on the stack
  3322   purge_previous_versions_internal(this, emcp_method_count);
  3324   int obsolete_method_count = old_methods->length() - emcp_method_count;
  3326   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
  3327       _previous_versions->length() > 0) {
  3328     // We have a mix of obsolete and EMCP methods so we have to
  3329     // clear out any matching EMCP method entries the hard way.
  3330     int local_count = 0;
  3331     for (int i = 0; i < old_methods->length(); i++) {
  3332       if (!emcp_methods->at(i)) {
  3333         // only obsolete methods are interesting
  3334         Method* old_method = old_methods->at(i);
  3335         Symbol* m_name = old_method->name();
  3336         Symbol* m_signature = old_method->signature();
  3338         // we might not have added the last entry
  3339         for (int j = _previous_versions->length() - 1; j >= 0; j--) {
  3340           // check the previous versions array for non executing obsolete methods
  3341           PreviousVersionNode * pv_node = _previous_versions->at(j);
  3343           GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3344           if (method_refs == NULL) {
  3345             // We have run into a PreviousVersion generation where
  3346             // all methods were made obsolete during that generation's
  3347             // RedefineClasses() operation. At the time of that
  3348             // operation, all EMCP methods were flushed so we don't
  3349             // have to go back any further.
  3350             //
  3351             // A NULL method_refs is different than an empty method_refs.
  3352             // We cannot infer any optimizations about older generations
  3353             // from an empty method_refs for the current generation.
  3354             break;
  3357           for (int k = method_refs->length() - 1; k >= 0; k--) {
  3358             Method* method = method_refs->at(k);
  3360             if (!method->is_obsolete() &&
  3361                 method->name() == m_name &&
  3362                 method->signature() == m_signature) {
  3363               // The current RedefineClasses() call has made all EMCP
  3364               // versions of this method obsolete so mark it as obsolete
  3365               // and remove the reference.
  3366               RC_TRACE(0x00000400,
  3367                 ("add: %s(%s): flush obsolete method @%d in version @%d",
  3368                 m_name->as_C_string(), m_signature->as_C_string(), k, j));
  3370               method->set_is_obsolete();
  3371               // Leave obsolete methods on the previous version list to
  3372               // clean up later.
  3373               break;
  3377           // The previous loop may not find a matching EMCP method, but
  3378           // that doesn't mean that we can optimize and not go any
  3379           // further back in the PreviousVersion generations. The EMCP
  3380           // method for this generation could have already been deleted,
  3381           // but there still may be an older EMCP method that has not
  3382           // been deleted.
  3385         if (++local_count >= obsolete_method_count) {
  3386           // no more obsolete methods so bail out now
  3387           break;
  3392 } // end add_previous_version()
  3395 // Determine if InstanceKlass has a previous version.
  3396 bool InstanceKlass::has_previous_version() const {
  3397   return (_previous_versions != NULL && _previous_versions->length() > 0);
  3398 } // end has_previous_version()
  3401 Method* InstanceKlass::method_with_idnum(int idnum) {
  3402   Method* m = NULL;
  3403   if (idnum < methods()->length()) {
  3404     m = methods()->at(idnum);
  3406   if (m == NULL || m->method_idnum() != idnum) {
  3407     for (int index = 0; index < methods()->length(); ++index) {
  3408       m = methods()->at(index);
  3409       if (m->method_idnum() == idnum) {
  3410         return m;
  3414   return m;
  3418 // Construct a PreviousVersionNode entry for the array hung off
  3419 // the InstanceKlass.
  3420 PreviousVersionNode::PreviousVersionNode(ConstantPool* prev_constant_pool,
  3421   bool prev_cp_is_weak, GrowableArray<Method*>* prev_EMCP_methods) {
  3423   _prev_constant_pool = prev_constant_pool;
  3424   _prev_cp_is_weak = prev_cp_is_weak;
  3425   _prev_EMCP_methods = prev_EMCP_methods;
  3429 // Destroy a PreviousVersionNode
  3430 PreviousVersionNode::~PreviousVersionNode() {
  3431   if (_prev_constant_pool != NULL) {
  3432     _prev_constant_pool = NULL;
  3435   if (_prev_EMCP_methods != NULL) {
  3436     delete _prev_EMCP_methods;
  3441 // Construct a PreviousVersionInfo entry
  3442 PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
  3443   _prev_constant_pool_handle = constantPoolHandle();  // NULL handle
  3444   _prev_EMCP_method_handles = NULL;
  3446   ConstantPool* cp = pv_node->prev_constant_pool();
  3447   assert(cp != NULL, "constant pool ref was unexpectedly cleared");
  3448   if (cp == NULL) {
  3449     return;  // robustness
  3452   // make the ConstantPool* safe to return
  3453   _prev_constant_pool_handle = constantPoolHandle(cp);
  3455   GrowableArray<Method*>* method_refs = pv_node->prev_EMCP_methods();
  3456   if (method_refs == NULL) {
  3457     // the InstanceKlass did not have any EMCP methods
  3458     return;
  3461   _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
  3463   int n_methods = method_refs->length();
  3464   for (int i = 0; i < n_methods; i++) {
  3465     Method* method = method_refs->at(i);
  3466     assert (method != NULL, "method has been cleared");
  3467     if (method == NULL) {
  3468       continue;  // robustness
  3470     // make the Method* safe to return
  3471     _prev_EMCP_method_handles->append(methodHandle(method));
  3476 // Destroy a PreviousVersionInfo
  3477 PreviousVersionInfo::~PreviousVersionInfo() {
  3478   // Since _prev_EMCP_method_handles is not C-heap allocated, we
  3479   // don't have to delete it.
  3483 // Construct a helper for walking the previous versions array
  3484 PreviousVersionWalker::PreviousVersionWalker(InstanceKlass *ik) {
  3485   _previous_versions = ik->previous_versions();
  3486   _current_index = 0;
  3487   // _hm needs no initialization
  3488   _current_p = NULL;
  3492 // Destroy a PreviousVersionWalker
  3493 PreviousVersionWalker::~PreviousVersionWalker() {
  3494   // Delete the current info just in case the caller didn't walk to
  3495   // the end of the previous versions list. No harm if _current_p is
  3496   // already NULL.
  3497   delete _current_p;
  3499   // When _hm is destroyed, all the Handles returned in
  3500   // PreviousVersionInfo objects will be destroyed.
  3501   // Also, after this destructor is finished it will be
  3502   // safe to delete the GrowableArray allocated in the
  3503   // PreviousVersionInfo objects.
  3507 // Return the interesting information for the next previous version
  3508 // of the klass. Returns NULL if there are no more previous versions.
  3509 PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
  3510   if (_previous_versions == NULL) {
  3511     // no previous versions so nothing to return
  3512     return NULL;
  3515   delete _current_p;  // cleanup the previous info for the caller
  3516   _current_p = NULL;  // reset to NULL so we don't delete same object twice
  3518   int length = _previous_versions->length();
  3520   while (_current_index < length) {
  3521     PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
  3522     PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP, mtClass)
  3523                                           PreviousVersionInfo(pv_node);
  3525     constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
  3526     assert (!cp_h.is_null(), "null cp found in previous version");
  3528     // The caller will need to delete pv_info when they are done with it.
  3529     _current_p = pv_info;
  3530     return pv_info;
  3533   // all of the underlying nodes' info has been deleted
  3534   return NULL;
  3535 } // end next_previous_version()

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