src/share/vm/oops/instanceKlass.cpp

Sat, 17 Mar 2012 17:31:59 -0400

author
dlong
date
Sat, 17 Mar 2012 17:31:59 -0400
changeset 3672
6522ad563f99
parent 3638
a735aec54ea4
parent 3670
f7c4174b33ba
child 3701
49036505ab5f
permissions
-rw-r--r--

Merge

     1 /*
     2  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "classfile/javaClasses.hpp"
    27 #include "classfile/systemDictionary.hpp"
    28 #include "classfile/verifier.hpp"
    29 #include "classfile/vmSymbols.hpp"
    30 #include "compiler/compileBroker.hpp"
    31 #include "gc_implementation/shared/markSweep.inline.hpp"
    32 #include "gc_interface/collectedHeap.inline.hpp"
    33 #include "interpreter/oopMapCache.hpp"
    34 #include "interpreter/rewriter.hpp"
    35 #include "jvmtifiles/jvmti.h"
    36 #include "memory/genOopClosures.inline.hpp"
    37 #include "memory/oopFactory.hpp"
    38 #include "memory/permGen.hpp"
    39 #include "oops/fieldStreams.hpp"
    40 #include "oops/instanceKlass.hpp"
    41 #include "oops/instanceMirrorKlass.hpp"
    42 #include "oops/instanceOop.hpp"
    43 #include "oops/methodOop.hpp"
    44 #include "oops/objArrayKlassKlass.hpp"
    45 #include "oops/oop.inline.hpp"
    46 #include "oops/symbol.hpp"
    47 #include "prims/jvmtiExport.hpp"
    48 #include "prims/jvmtiRedefineClassesTrace.hpp"
    49 #include "runtime/fieldDescriptor.hpp"
    50 #include "runtime/handles.inline.hpp"
    51 #include "runtime/javaCalls.hpp"
    52 #include "runtime/mutexLocker.hpp"
    53 #include "services/threadService.hpp"
    54 #include "utilities/dtrace.hpp"
    55 #ifdef TARGET_OS_FAMILY_linux
    56 # include "thread_linux.inline.hpp"
    57 #endif
    58 #ifdef TARGET_OS_FAMILY_solaris
    59 # include "thread_solaris.inline.hpp"
    60 #endif
    61 #ifdef TARGET_OS_FAMILY_windows
    62 # include "thread_windows.inline.hpp"
    63 #endif
    64 #ifdef TARGET_OS_FAMILY_bsd
    65 # include "thread_bsd.inline.hpp"
    66 #endif
    67 #ifndef SERIALGC
    68 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
    69 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
    70 #include "gc_implementation/g1/g1RemSet.inline.hpp"
    71 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
    72 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
    73 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
    74 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
    75 #include "oops/oop.pcgc.inline.hpp"
    76 #endif
    77 #ifdef COMPILER1
    78 #include "c1/c1_Compiler.hpp"
    79 #endif
    81 #ifdef DTRACE_ENABLED
    83 #ifndef USDT2
    85 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
    86   char*, intptr_t, oop, intptr_t);
    87 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
    88   char*, intptr_t, oop, intptr_t, int);
    89 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
    90   char*, intptr_t, oop, intptr_t, int);
    91 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
    92   char*, intptr_t, oop, intptr_t, int);
    93 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
    94   char*, intptr_t, oop, intptr_t, int);
    95 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
    96   char*, intptr_t, oop, intptr_t, int);
    97 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
    98   char*, intptr_t, oop, intptr_t, int);
    99 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
   100   char*, intptr_t, oop, intptr_t, int);
   102 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
   103   {                                                              \
   104     char* data = NULL;                                           \
   105     int len = 0;                                                 \
   106     Symbol* name = (clss)->name();                               \
   107     if (name != NULL) {                                          \
   108       data = (char*)name->bytes();                               \
   109       len = name->utf8_length();                                 \
   110     }                                                            \
   111     HS_DTRACE_PROBE4(hotspot, class__initialization__##type,     \
   112       data, len, (clss)->class_loader(), thread_type);           \
   113   }
   115 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
   116   {                                                              \
   117     char* data = NULL;                                           \
   118     int len = 0;                                                 \
   119     Symbol* name = (clss)->name();                               \
   120     if (name != NULL) {                                          \
   121       data = (char*)name->bytes();                               \
   122       len = name->utf8_length();                                 \
   123     }                                                            \
   124     HS_DTRACE_PROBE5(hotspot, class__initialization__##type,     \
   125       data, len, (clss)->class_loader(), thread_type, wait);     \
   126   }
   127 #else /* USDT2 */
   129 #define HOTSPOT_CLASS_INITIALIZATION_required HOTSPOT_CLASS_INITIALIZATION_REQUIRED
   130 #define HOTSPOT_CLASS_INITIALIZATION_recursive HOTSPOT_CLASS_INITIALIZATION_RECURSIVE
   131 #define HOTSPOT_CLASS_INITIALIZATION_concurrent HOTSPOT_CLASS_INITIALIZATION_CONCURRENT
   132 #define HOTSPOT_CLASS_INITIALIZATION_erroneous HOTSPOT_CLASS_INITIALIZATION_ERRONEOUS
   133 #define HOTSPOT_CLASS_INITIALIZATION_super__failed HOTSPOT_CLASS_INITIALIZATION_SUPER_FAILED
   134 #define HOTSPOT_CLASS_INITIALIZATION_clinit HOTSPOT_CLASS_INITIALIZATION_CLINIT
   135 #define HOTSPOT_CLASS_INITIALIZATION_error HOTSPOT_CLASS_INITIALIZATION_ERROR
   136 #define HOTSPOT_CLASS_INITIALIZATION_end HOTSPOT_CLASS_INITIALIZATION_END
   137 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
   138   {                                                              \
   139     char* data = NULL;                                           \
   140     int len = 0;                                                 \
   141     Symbol* name = (clss)->name();                               \
   142     if (name != NULL) {                                          \
   143       data = (char*)name->bytes();                               \
   144       len = name->utf8_length();                                 \
   145     }                                                            \
   146     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
   147       data, len, (clss)->class_loader(), thread_type);           \
   148   }
   150 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
   151   {                                                              \
   152     char* data = NULL;                                           \
   153     int len = 0;                                                 \
   154     Symbol* name = (clss)->name();                               \
   155     if (name != NULL) {                                          \
   156       data = (char*)name->bytes();                               \
   157       len = name->utf8_length();                                 \
   158     }                                                            \
   159     HOTSPOT_CLASS_INITIALIZATION_##type(                         \
   160       data, len, (clss)->class_loader(), thread_type, wait);     \
   161   }
   162 #endif /* USDT2 */
   164 #else //  ndef DTRACE_ENABLED
   166 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
   167 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
   169 #endif //  ndef DTRACE_ENABLED
   171 bool instanceKlass::should_be_initialized() const {
   172   return !is_initialized();
   173 }
   175 klassVtable* instanceKlass::vtable() const {
   176   return new klassVtable(as_klassOop(), start_of_vtable(), vtable_length() / vtableEntry::size());
   177 }
   179 klassItable* instanceKlass::itable() const {
   180   return new klassItable(as_klassOop());
   181 }
   183 void instanceKlass::eager_initialize(Thread *thread) {
   184   if (!EagerInitialization) return;
   186   if (this->is_not_initialized()) {
   187     // abort if the the class has a class initializer
   188     if (this->class_initializer() != NULL) return;
   190     // abort if it is java.lang.Object (initialization is handled in genesis)
   191     klassOop super = this->super();
   192     if (super == NULL) return;
   194     // abort if the super class should be initialized
   195     if (!instanceKlass::cast(super)->is_initialized()) return;
   197     // call body to expose the this pointer
   198     instanceKlassHandle this_oop(thread, this->as_klassOop());
   199     eager_initialize_impl(this_oop);
   200   }
   201 }
   204 void instanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
   205   EXCEPTION_MARK;
   206   ObjectLocker ol(this_oop, THREAD);
   208   // abort if someone beat us to the initialization
   209   if (!this_oop->is_not_initialized()) return;  // note: not equivalent to is_initialized()
   211   ClassState old_state = this_oop->init_state();
   212   link_class_impl(this_oop, true, THREAD);
   213   if (HAS_PENDING_EXCEPTION) {
   214     CLEAR_PENDING_EXCEPTION;
   215     // Abort if linking the class throws an exception.
   217     // Use a test to avoid redundantly resetting the state if there's
   218     // no change.  Set_init_state() asserts that state changes make
   219     // progress, whereas here we might just be spinning in place.
   220     if( old_state != this_oop->_init_state )
   221       this_oop->set_init_state (old_state);
   222   } else {
   223     // linking successfull, mark class as initialized
   224     this_oop->set_init_state (fully_initialized);
   225     // trace
   226     if (TraceClassInitialization) {
   227       ResourceMark rm(THREAD);
   228       tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
   229     }
   230   }
   231 }
   234 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
   235 // process. The step comments refers to the procedure described in that section.
   236 // Note: implementation moved to static method to expose the this pointer.
   237 void instanceKlass::initialize(TRAPS) {
   238   if (this->should_be_initialized()) {
   239     HandleMark hm(THREAD);
   240     instanceKlassHandle this_oop(THREAD, this->as_klassOop());
   241     initialize_impl(this_oop, CHECK);
   242     // Note: at this point the class may be initialized
   243     //       OR it may be in the state of being initialized
   244     //       in case of recursive initialization!
   245   } else {
   246     assert(is_initialized(), "sanity check");
   247   }
   248 }
   251 bool instanceKlass::verify_code(
   252     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
   253   // 1) Verify the bytecodes
   254   Verifier::Mode mode =
   255     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
   256   return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
   257 }
   260 // Used exclusively by the shared spaces dump mechanism to prevent
   261 // classes mapped into the shared regions in new VMs from appearing linked.
   263 void instanceKlass::unlink_class() {
   264   assert(is_linked(), "must be linked");
   265   _init_state = loaded;
   266 }
   268 void instanceKlass::link_class(TRAPS) {
   269   assert(is_loaded(), "must be loaded");
   270   if (!is_linked()) {
   271     instanceKlassHandle this_oop(THREAD, this->as_klassOop());
   272     link_class_impl(this_oop, true, CHECK);
   273   }
   274 }
   276 // Called to verify that a class can link during initialization, without
   277 // throwing a VerifyError.
   278 bool instanceKlass::link_class_or_fail(TRAPS) {
   279   assert(is_loaded(), "must be loaded");
   280   if (!is_linked()) {
   281     instanceKlassHandle this_oop(THREAD, this->as_klassOop());
   282     link_class_impl(this_oop, false, CHECK_false);
   283   }
   284   return is_linked();
   285 }
   287 bool instanceKlass::link_class_impl(
   288     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
   289   // check for error state
   290   if (this_oop->is_in_error_state()) {
   291     ResourceMark rm(THREAD);
   292     THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
   293                this_oop->external_name(), false);
   294   }
   295   // return if already verified
   296   if (this_oop->is_linked()) {
   297     return true;
   298   }
   300   // Timing
   301   // timer handles recursion
   302   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
   303   JavaThread* jt = (JavaThread*)THREAD;
   305   // link super class before linking this class
   306   instanceKlassHandle super(THREAD, this_oop->super());
   307   if (super.not_null()) {
   308     if (super->is_interface()) {  // check if super class is an interface
   309       ResourceMark rm(THREAD);
   310       Exceptions::fthrow(
   311         THREAD_AND_LOCATION,
   312         vmSymbols::java_lang_IncompatibleClassChangeError(),
   313         "class %s has interface %s as super class",
   314         this_oop->external_name(),
   315         super->external_name()
   316       );
   317       return false;
   318     }
   320     link_class_impl(super, throw_verifyerror, CHECK_false);
   321   }
   323   // link all interfaces implemented by this class before linking this class
   324   objArrayHandle interfaces (THREAD, this_oop->local_interfaces());
   325   int num_interfaces = interfaces->length();
   326   for (int index = 0; index < num_interfaces; index++) {
   327     HandleMark hm(THREAD);
   328     instanceKlassHandle ih(THREAD, klassOop(interfaces->obj_at(index)));
   329     link_class_impl(ih, throw_verifyerror, CHECK_false);
   330   }
   332   // in case the class is linked in the process of linking its superclasses
   333   if (this_oop->is_linked()) {
   334     return true;
   335   }
   337   // trace only the link time for this klass that includes
   338   // the verification time
   339   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
   340                              ClassLoader::perf_class_link_selftime(),
   341                              ClassLoader::perf_classes_linked(),
   342                              jt->get_thread_stat()->perf_recursion_counts_addr(),
   343                              jt->get_thread_stat()->perf_timers_addr(),
   344                              PerfClassTraceTime::CLASS_LINK);
   346   // verification & rewriting
   347   {
   348     ObjectLocker ol(this_oop, THREAD);
   349     // rewritten will have been set if loader constraint error found
   350     // on an earlier link attempt
   351     // don't verify or rewrite if already rewritten
   352     if (!this_oop->is_linked()) {
   353       if (!this_oop->is_rewritten()) {
   354         {
   355           // Timer includes any side effects of class verification (resolution,
   356           // etc), but not recursive entry into verify_code().
   357           PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
   358                                    ClassLoader::perf_class_verify_selftime(),
   359                                    ClassLoader::perf_classes_verified(),
   360                                    jt->get_thread_stat()->perf_recursion_counts_addr(),
   361                                    jt->get_thread_stat()->perf_timers_addr(),
   362                                    PerfClassTraceTime::CLASS_VERIFY);
   363           bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
   364           if (!verify_ok) {
   365             return false;
   366           }
   367         }
   369         // Just in case a side-effect of verify linked this class already
   370         // (which can sometimes happen since the verifier loads classes
   371         // using custom class loaders, which are free to initialize things)
   372         if (this_oop->is_linked()) {
   373           return true;
   374         }
   376         // also sets rewritten
   377         this_oop->rewrite_class(CHECK_false);
   378       }
   380       // relocate jsrs and link methods after they are all rewritten
   381       this_oop->relocate_and_link_methods(CHECK_false);
   383       // Initialize the vtable and interface table after
   384       // methods have been rewritten since rewrite may
   385       // fabricate new methodOops.
   386       // also does loader constraint checking
   387       if (!this_oop()->is_shared()) {
   388         ResourceMark rm(THREAD);
   389         this_oop->vtable()->initialize_vtable(true, CHECK_false);
   390         this_oop->itable()->initialize_itable(true, CHECK_false);
   391       }
   392 #ifdef ASSERT
   393       else {
   394         ResourceMark rm(THREAD);
   395         this_oop->vtable()->verify(tty, true);
   396         // In case itable verification is ever added.
   397         // this_oop->itable()->verify(tty, true);
   398       }
   399 #endif
   400       this_oop->set_init_state(linked);
   401       if (JvmtiExport::should_post_class_prepare()) {
   402         Thread *thread = THREAD;
   403         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
   404         JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
   405       }
   406     }
   407   }
   408   return true;
   409 }
   412 // Rewrite the byte codes of all of the methods of a class.
   413 // The rewriter must be called exactly once. Rewriting must happen after
   414 // verification but before the first method of the class is executed.
   415 void instanceKlass::rewrite_class(TRAPS) {
   416   assert(is_loaded(), "must be loaded");
   417   instanceKlassHandle this_oop(THREAD, this->as_klassOop());
   418   if (this_oop->is_rewritten()) {
   419     assert(this_oop()->is_shared(), "rewriting an unshared class?");
   420     return;
   421   }
   422   Rewriter::rewrite(this_oop, CHECK);
   423   this_oop->set_rewritten();
   424 }
   426 // Now relocate and link method entry points after class is rewritten.
   427 // This is outside is_rewritten flag. In case of an exception, it can be
   428 // executed more than once.
   429 void instanceKlass::relocate_and_link_methods(TRAPS) {
   430   assert(is_loaded(), "must be loaded");
   431   instanceKlassHandle this_oop(THREAD, this->as_klassOop());
   432   Rewriter::relocate_and_link(this_oop, CHECK);
   433 }
   436 void instanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
   437   // Make sure klass is linked (verified) before initialization
   438   // A class could already be verified, since it has been reflected upon.
   439   this_oop->link_class(CHECK);
   441   DTRACE_CLASSINIT_PROBE(required, instanceKlass::cast(this_oop()), -1);
   443   bool wait = false;
   445   // refer to the JVM book page 47 for description of steps
   446   // Step 1
   447   { ObjectLocker ol(this_oop, THREAD);
   449     Thread *self = THREAD; // it's passed the current thread
   451     // Step 2
   452     // If we were to use wait() instead of waitInterruptibly() then
   453     // we might end up throwing IE from link/symbol resolution sites
   454     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
   455     while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
   456         wait = true;
   457       ol.waitUninterruptibly(CHECK);
   458     }
   460     // Step 3
   461     if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
   462       DTRACE_CLASSINIT_PROBE_WAIT(recursive, instanceKlass::cast(this_oop()), -1,wait);
   463       return;
   464     }
   466     // Step 4
   467     if (this_oop->is_initialized()) {
   468       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, instanceKlass::cast(this_oop()), -1,wait);
   469       return;
   470     }
   472     // Step 5
   473     if (this_oop->is_in_error_state()) {
   474       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, instanceKlass::cast(this_oop()), -1,wait);
   475       ResourceMark rm(THREAD);
   476       const char* desc = "Could not initialize class ";
   477       const char* className = this_oop->external_name();
   478       size_t msglen = strlen(desc) + strlen(className) + 1;
   479       char* message = NEW_RESOURCE_ARRAY(char, msglen);
   480       if (NULL == message) {
   481         // Out of memory: can't create detailed error message
   482         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
   483       } else {
   484         jio_snprintf(message, msglen, "%s%s", desc, className);
   485         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
   486       }
   487     }
   489     // Step 6
   490     this_oop->set_init_state(being_initialized);
   491     this_oop->set_init_thread(self);
   492   }
   494   // Step 7
   495   klassOop super_klass = this_oop->super();
   496   if (super_klass != NULL && !this_oop->is_interface() && Klass::cast(super_klass)->should_be_initialized()) {
   497     Klass::cast(super_klass)->initialize(THREAD);
   499     if (HAS_PENDING_EXCEPTION) {
   500       Handle e(THREAD, PENDING_EXCEPTION);
   501       CLEAR_PENDING_EXCEPTION;
   502       {
   503         EXCEPTION_MARK;
   504         this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
   505         CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, superclass initialization error is thrown below
   506       }
   507       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, instanceKlass::cast(this_oop()), -1,wait);
   508       THROW_OOP(e());
   509     }
   510   }
   512   // Step 8
   513   {
   514     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
   515     JavaThread* jt = (JavaThread*)THREAD;
   516     DTRACE_CLASSINIT_PROBE_WAIT(clinit, instanceKlass::cast(this_oop()), -1,wait);
   517     // Timer includes any side effects of class initialization (resolution,
   518     // etc), but not recursive entry into call_class_initializer().
   519     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
   520                              ClassLoader::perf_class_init_selftime(),
   521                              ClassLoader::perf_classes_inited(),
   522                              jt->get_thread_stat()->perf_recursion_counts_addr(),
   523                              jt->get_thread_stat()->perf_timers_addr(),
   524                              PerfClassTraceTime::CLASS_CLINIT);
   525     this_oop->call_class_initializer(THREAD);
   526   }
   528   // Step 9
   529   if (!HAS_PENDING_EXCEPTION) {
   530     this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
   531     { ResourceMark rm(THREAD);
   532       debug_only(this_oop->vtable()->verify(tty, true);)
   533     }
   534   }
   535   else {
   536     // Step 10 and 11
   537     Handle e(THREAD, PENDING_EXCEPTION);
   538     CLEAR_PENDING_EXCEPTION;
   539     {
   540       EXCEPTION_MARK;
   541       this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
   542       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
   543     }
   544     DTRACE_CLASSINIT_PROBE_WAIT(error, instanceKlass::cast(this_oop()), -1,wait);
   545     if (e->is_a(SystemDictionary::Error_klass())) {
   546       THROW_OOP(e());
   547     } else {
   548       JavaCallArguments args(e);
   549       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
   550                 vmSymbols::throwable_void_signature(),
   551                 &args);
   552     }
   553   }
   554   DTRACE_CLASSINIT_PROBE_WAIT(end, instanceKlass::cast(this_oop()), -1,wait);
   555 }
   558 // Note: implementation moved to static method to expose the this pointer.
   559 void instanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
   560   instanceKlassHandle kh(THREAD, this->as_klassOop());
   561   set_initialization_state_and_notify_impl(kh, state, CHECK);
   562 }
   564 void instanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
   565   ObjectLocker ol(this_oop, THREAD);
   566   this_oop->set_init_state(state);
   567   ol.notify_all(CHECK);
   568 }
   570 void instanceKlass::add_implementor(klassOop k) {
   571   assert(Compile_lock->owned_by_self(), "");
   572   // Filter out my subinterfaces.
   573   // (Note: Interfaces are never on the subklass list.)
   574   if (instanceKlass::cast(k)->is_interface()) return;
   576   // Filter out subclasses whose supers already implement me.
   577   // (Note: CHA must walk subclasses of direct implementors
   578   // in order to locate indirect implementors.)
   579   klassOop sk = instanceKlass::cast(k)->super();
   580   if (sk != NULL && instanceKlass::cast(sk)->implements_interface(as_klassOop()))
   581     // We only need to check one immediate superclass, since the
   582     // implements_interface query looks at transitive_interfaces.
   583     // Any supers of the super have the same (or fewer) transitive_interfaces.
   584     return;
   586   // Update number of implementors
   587   int i = _nof_implementors++;
   589   // Record this implementor, if there are not too many already
   590   if (i < implementors_limit) {
   591     assert(_implementors[i] == NULL, "should be exactly one implementor");
   592     oop_store_without_check((oop*)&_implementors[i], k);
   593   } else if (i == implementors_limit) {
   594     // clear out the list on first overflow
   595     for (int i2 = 0; i2 < implementors_limit; i2++)
   596       oop_store_without_check((oop*)&_implementors[i2], NULL);
   597   }
   599   // The implementor also implements the transitive_interfaces
   600   for (int index = 0; index < local_interfaces()->length(); index++) {
   601     instanceKlass::cast(klassOop(local_interfaces()->obj_at(index)))->add_implementor(k);
   602   }
   603 }
   605 void instanceKlass::init_implementor() {
   606   for (int i = 0; i < implementors_limit; i++)
   607     oop_store_without_check((oop*)&_implementors[i], NULL);
   608   _nof_implementors = 0;
   609 }
   612 void instanceKlass::process_interfaces(Thread *thread) {
   613   // link this class into the implementors list of every interface it implements
   614   KlassHandle this_as_oop (thread, this->as_klassOop());
   615   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
   616     assert(local_interfaces()->obj_at(i)->is_klass(), "must be a klass");
   617     instanceKlass* interf = instanceKlass::cast(klassOop(local_interfaces()->obj_at(i)));
   618     assert(interf->is_interface(), "expected interface");
   619     interf->add_implementor(this_as_oop());
   620   }
   621 }
   623 bool instanceKlass::can_be_primary_super_slow() const {
   624   if (is_interface())
   625     return false;
   626   else
   627     return Klass::can_be_primary_super_slow();
   628 }
   630 objArrayOop instanceKlass::compute_secondary_supers(int num_extra_slots, TRAPS) {
   631   // The secondaries are the implemented interfaces.
   632   instanceKlass* ik = instanceKlass::cast(as_klassOop());
   633   objArrayHandle interfaces (THREAD, ik->transitive_interfaces());
   634   int num_secondaries = num_extra_slots + interfaces->length();
   635   if (num_secondaries == 0) {
   636     return Universe::the_empty_system_obj_array();
   637   } else if (num_extra_slots == 0) {
   638     return interfaces();
   639   } else {
   640     // a mix of both
   641     objArrayOop secondaries = oopFactory::new_system_objArray(num_secondaries, CHECK_NULL);
   642     for (int i = 0; i < interfaces->length(); i++) {
   643       secondaries->obj_at_put(num_extra_slots+i, interfaces->obj_at(i));
   644     }
   645     return secondaries;
   646   }
   647 }
   649 bool instanceKlass::compute_is_subtype_of(klassOop k) {
   650   if (Klass::cast(k)->is_interface()) {
   651     return implements_interface(k);
   652   } else {
   653     return Klass::compute_is_subtype_of(k);
   654   }
   655 }
   657 bool instanceKlass::implements_interface(klassOop k) const {
   658   if (as_klassOop() == k) return true;
   659   assert(Klass::cast(k)->is_interface(), "should be an interface class");
   660   for (int i = 0; i < transitive_interfaces()->length(); i++) {
   661     if (transitive_interfaces()->obj_at(i) == k) {
   662       return true;
   663     }
   664   }
   665   return false;
   666 }
   668 objArrayOop instanceKlass::allocate_objArray(int n, int length, TRAPS) {
   669   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
   670   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
   671     report_java_out_of_memory("Requested array size exceeds VM limit");
   672     JvmtiExport::post_array_size_exhausted();
   673     THROW_OOP_0(Universe::out_of_memory_error_array_size());
   674   }
   675   int size = objArrayOopDesc::object_size(length);
   676   klassOop ak = array_klass(n, CHECK_NULL);
   677   KlassHandle h_ak (THREAD, ak);
   678   objArrayOop o =
   679     (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
   680   return o;
   681 }
   683 instanceOop instanceKlass::register_finalizer(instanceOop i, TRAPS) {
   684   if (TraceFinalizerRegistration) {
   685     tty->print("Registered ");
   686     i->print_value_on(tty);
   687     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
   688   }
   689   instanceHandle h_i(THREAD, i);
   690   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
   691   JavaValue result(T_VOID);
   692   JavaCallArguments args(h_i);
   693   methodHandle mh (THREAD, Universe::finalizer_register_method());
   694   JavaCalls::call(&result, mh, &args, CHECK_NULL);
   695   return h_i();
   696 }
   698 instanceOop instanceKlass::allocate_instance(TRAPS) {
   699   assert(!oop_is_instanceMirror(), "wrong allocation path");
   700   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
   701   int size = size_helper();  // Query before forming handle.
   703   KlassHandle h_k(THREAD, as_klassOop());
   705   instanceOop i;
   707   i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
   708   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
   709     i = register_finalizer(i, CHECK_NULL);
   710   }
   711   return i;
   712 }
   714 instanceOop instanceKlass::allocate_permanent_instance(TRAPS) {
   715   // Finalizer registration occurs in the Object.<init> constructor
   716   // and constructors normally aren't run when allocating perm
   717   // instances so simply disallow finalizable perm objects.  This can
   718   // be relaxed if a need for it is found.
   719   assert(!has_finalizer(), "perm objects not allowed to have finalizers");
   720   assert(!oop_is_instanceMirror(), "wrong allocation path");
   721   int size = size_helper();  // Query before forming handle.
   722   KlassHandle h_k(THREAD, as_klassOop());
   723   instanceOop i = (instanceOop)
   724     CollectedHeap::permanent_obj_allocate(h_k, size, CHECK_NULL);
   725   return i;
   726 }
   728 void instanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
   729   if (is_interface() || is_abstract()) {
   730     ResourceMark rm(THREAD);
   731     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
   732               : vmSymbols::java_lang_InstantiationException(), external_name());
   733   }
   734   if (as_klassOop() == SystemDictionary::Class_klass()) {
   735     ResourceMark rm(THREAD);
   736     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
   737               : vmSymbols::java_lang_IllegalAccessException(), external_name());
   738   }
   739 }
   741 klassOop instanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
   742   instanceKlassHandle this_oop(THREAD, as_klassOop());
   743   return array_klass_impl(this_oop, or_null, n, THREAD);
   744 }
   746 klassOop instanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
   747   if (this_oop->array_klasses() == NULL) {
   748     if (or_null) return NULL;
   750     ResourceMark rm;
   751     JavaThread *jt = (JavaThread *)THREAD;
   752     {
   753       // Atomic creation of array_klasses
   754       MutexLocker mc(Compile_lock, THREAD);   // for vtables
   755       MutexLocker ma(MultiArray_lock, THREAD);
   757       // Check if update has already taken place
   758       if (this_oop->array_klasses() == NULL) {
   759         objArrayKlassKlass* oakk =
   760           (objArrayKlassKlass*)Universe::objArrayKlassKlassObj()->klass_part();
   762         klassOop  k = oakk->allocate_objArray_klass(1, this_oop, CHECK_NULL);
   763         this_oop->set_array_klasses(k);
   764       }
   765     }
   766   }
   767   // _this will always be set at this point
   768   objArrayKlass* oak = (objArrayKlass*)this_oop->array_klasses()->klass_part();
   769   if (or_null) {
   770     return oak->array_klass_or_null(n);
   771   }
   772   return oak->array_klass(n, CHECK_NULL);
   773 }
   775 klassOop instanceKlass::array_klass_impl(bool or_null, TRAPS) {
   776   return array_klass_impl(or_null, 1, THREAD);
   777 }
   779 void instanceKlass::call_class_initializer(TRAPS) {
   780   instanceKlassHandle ik (THREAD, as_klassOop());
   781   call_class_initializer_impl(ik, THREAD);
   782 }
   784 static int call_class_initializer_impl_counter = 0;   // for debugging
   786 methodOop instanceKlass::class_initializer() {
   787   methodOop clinit = find_method(
   788       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
   789   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
   790     return clinit;
   791   }
   792   return NULL;
   793 }
   795 void instanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
   796   methodHandle h_method(THREAD, this_oop->class_initializer());
   797   assert(!this_oop->is_initialized(), "we cannot initialize twice");
   798   if (TraceClassInitialization) {
   799     tty->print("%d Initializing ", call_class_initializer_impl_counter++);
   800     this_oop->name()->print_value();
   801     tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
   802   }
   803   if (h_method() != NULL) {
   804     JavaCallArguments args; // No arguments
   805     JavaValue result(T_VOID);
   806     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
   807   }
   808 }
   811 void instanceKlass::mask_for(methodHandle method, int bci,
   812   InterpreterOopMap* entry_for) {
   813   // Dirty read, then double-check under a lock.
   814   if (_oop_map_cache == NULL) {
   815     // Otherwise, allocate a new one.
   816     MutexLocker x(OopMapCacheAlloc_lock);
   817     // First time use. Allocate a cache in C heap
   818     if (_oop_map_cache == NULL) {
   819       _oop_map_cache = new OopMapCache();
   820     }
   821   }
   822   // _oop_map_cache is constant after init; lookup below does is own locking.
   823   _oop_map_cache->lookup(method, bci, entry_for);
   824 }
   827 bool instanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
   828   for (JavaFieldStream fs(as_klassOop()); !fs.done(); fs.next()) {
   829     Symbol* f_name = fs.name();
   830     Symbol* f_sig  = fs.signature();
   831     if (f_name == name && f_sig == sig) {
   832       fd->initialize(as_klassOop(), fs.index());
   833       return true;
   834     }
   835   }
   836   return false;
   837 }
   840 void instanceKlass::shared_symbols_iterate(SymbolClosure* closure) {
   841   Klass::shared_symbols_iterate(closure);
   842   closure->do_symbol(&_generic_signature);
   843   closure->do_symbol(&_source_file_name);
   844   closure->do_symbol(&_source_debug_extension);
   846   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
   847     int name_index = fs.name_index();
   848     closure->do_symbol(constants()->symbol_at_addr(name_index));
   849     int sig_index  = fs.signature_index();
   850     closure->do_symbol(constants()->symbol_at_addr(sig_index));
   851   }
   852 }
   855 klassOop instanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
   856   const int n = local_interfaces()->length();
   857   for (int i = 0; i < n; i++) {
   858     klassOop intf1 = klassOop(local_interfaces()->obj_at(i));
   859     assert(Klass::cast(intf1)->is_interface(), "just checking type");
   860     // search for field in current interface
   861     if (instanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
   862       assert(fd->is_static(), "interface field must be static");
   863       return intf1;
   864     }
   865     // search for field in direct superinterfaces
   866     klassOop intf2 = instanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
   867     if (intf2 != NULL) return intf2;
   868   }
   869   // otherwise field lookup fails
   870   return NULL;
   871 }
   874 klassOop instanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
   875   // search order according to newest JVM spec (5.4.3.2, p.167).
   876   // 1) search for field in current klass
   877   if (find_local_field(name, sig, fd)) {
   878     return as_klassOop();
   879   }
   880   // 2) search for field recursively in direct superinterfaces
   881   { klassOop intf = find_interface_field(name, sig, fd);
   882     if (intf != NULL) return intf;
   883   }
   884   // 3) apply field lookup recursively if superclass exists
   885   { klassOop supr = super();
   886     if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, fd);
   887   }
   888   // 4) otherwise field lookup fails
   889   return NULL;
   890 }
   893 klassOop instanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
   894   // search order according to newest JVM spec (5.4.3.2, p.167).
   895   // 1) search for field in current klass
   896   if (find_local_field(name, sig, fd)) {
   897     if (fd->is_static() == is_static) return as_klassOop();
   898   }
   899   // 2) search for field recursively in direct superinterfaces
   900   if (is_static) {
   901     klassOop intf = find_interface_field(name, sig, fd);
   902     if (intf != NULL) return intf;
   903   }
   904   // 3) apply field lookup recursively if superclass exists
   905   { klassOop supr = super();
   906     if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
   907   }
   908   // 4) otherwise field lookup fails
   909   return NULL;
   910 }
   913 bool instanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
   914   for (JavaFieldStream fs(as_klassOop()); !fs.done(); fs.next()) {
   915     if (fs.offset() == offset) {
   916       fd->initialize(as_klassOop(), fs.index());
   917       if (fd->is_static() == is_static) return true;
   918     }
   919   }
   920   return false;
   921 }
   924 bool instanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
   925   klassOop klass = as_klassOop();
   926   while (klass != NULL) {
   927     if (instanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
   928       return true;
   929     }
   930     klass = Klass::cast(klass)->super();
   931   }
   932   return false;
   933 }
   936 void instanceKlass::methods_do(void f(methodOop method)) {
   937   int len = methods()->length();
   938   for (int index = 0; index < len; index++) {
   939     methodOop m = methodOop(methods()->obj_at(index));
   940     assert(m->is_method(), "must be method");
   941     f(m);
   942   }
   943 }
   946 void instanceKlass::do_local_static_fields(FieldClosure* cl) {
   947   for (JavaFieldStream fs(this); !fs.done(); fs.next()) {
   948     if (fs.access_flags().is_static()) {
   949       fieldDescriptor fd;
   950       fd.initialize(as_klassOop(), fs.index());
   951       cl->do_field(&fd);
   952     }
   953   }
   954 }
   957 void instanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
   958   instanceKlassHandle h_this(THREAD, as_klassOop());
   959   do_local_static_fields_impl(h_this, f, CHECK);
   960 }
   963 void instanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
   964   for (JavaFieldStream fs(this_oop()); !fs.done(); fs.next()) {
   965     if (fs.access_flags().is_static()) {
   966       fieldDescriptor fd;
   967       fd.initialize(this_oop(), fs.index());
   968       f(&fd, CHECK);
   969     }
   970   }
   971 }
   974 static int compare_fields_by_offset(int* a, int* b) {
   975   return a[0] - b[0];
   976 }
   978 void instanceKlass::do_nonstatic_fields(FieldClosure* cl) {
   979   instanceKlass* super = superklass();
   980   if (super != NULL) {
   981     super->do_nonstatic_fields(cl);
   982   }
   983   fieldDescriptor fd;
   984   int length = java_fields_count();
   985   // In DebugInfo nonstatic fields are sorted by offset.
   986   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1));
   987   int j = 0;
   988   for (int i = 0; i < length; i += 1) {
   989     fd.initialize(as_klassOop(), i);
   990     if (!fd.is_static()) {
   991       fields_sorted[j + 0] = fd.offset();
   992       fields_sorted[j + 1] = i;
   993       j += 2;
   994     }
   995   }
   996   if (j > 0) {
   997     length = j;
   998     // _sort_Fn is defined in growableArray.hpp.
   999     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
  1000     for (int i = 0; i < length; i += 2) {
  1001       fd.initialize(as_klassOop(), fields_sorted[i + 1]);
  1002       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
  1003       cl->do_field(&fd);
  1006   FREE_C_HEAP_ARRAY(int, fields_sorted);
  1010 void instanceKlass::array_klasses_do(void f(klassOop k)) {
  1011   if (array_klasses() != NULL)
  1012     arrayKlass::cast(array_klasses())->array_klasses_do(f);
  1016 void instanceKlass::with_array_klasses_do(void f(klassOop k)) {
  1017   f(as_klassOop());
  1018   array_klasses_do(f);
  1021 #ifdef ASSERT
  1022 static int linear_search(objArrayOop methods, Symbol* name, Symbol* signature) {
  1023   int len = methods->length();
  1024   for (int index = 0; index < len; index++) {
  1025     methodOop m = (methodOop)(methods->obj_at(index));
  1026     assert(m->is_method(), "must be method");
  1027     if (m->signature() == signature && m->name() == name) {
  1028        return index;
  1031   return -1;
  1033 #endif
  1035 methodOop instanceKlass::find_method(Symbol* name, Symbol* signature) const {
  1036   return instanceKlass::find_method(methods(), name, signature);
  1039 methodOop instanceKlass::find_method(objArrayOop methods, Symbol* name, Symbol* signature) {
  1040   int len = methods->length();
  1041   // methods are sorted, so do binary search
  1042   int l = 0;
  1043   int h = len - 1;
  1044   while (l <= h) {
  1045     int mid = (l + h) >> 1;
  1046     methodOop m = (methodOop)methods->obj_at(mid);
  1047     assert(m->is_method(), "must be method");
  1048     int res = m->name()->fast_compare(name);
  1049     if (res == 0) {
  1050       // found matching name; do linear search to find matching signature
  1051       // first, quick check for common case
  1052       if (m->signature() == signature) return m;
  1053       // search downwards through overloaded methods
  1054       int i;
  1055       for (i = mid - 1; i >= l; i--) {
  1056         methodOop m = (methodOop)methods->obj_at(i);
  1057         assert(m->is_method(), "must be method");
  1058         if (m->name() != name) break;
  1059         if (m->signature() == signature) return m;
  1061       // search upwards
  1062       for (i = mid + 1; i <= h; i++) {
  1063         methodOop m = (methodOop)methods->obj_at(i);
  1064         assert(m->is_method(), "must be method");
  1065         if (m->name() != name) break;
  1066         if (m->signature() == signature) return m;
  1068       // not found
  1069 #ifdef ASSERT
  1070       int index = linear_search(methods, name, signature);
  1071       assert(index == -1, err_msg("binary search should have found entry %d", index));
  1072 #endif
  1073       return NULL;
  1074     } else if (res < 0) {
  1075       l = mid + 1;
  1076     } else {
  1077       h = mid - 1;
  1080 #ifdef ASSERT
  1081   int index = linear_search(methods, name, signature);
  1082   assert(index == -1, err_msg("binary search should have found entry %d", index));
  1083 #endif
  1084   return NULL;
  1087 methodOop instanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
  1088   klassOop klass = as_klassOop();
  1089   while (klass != NULL) {
  1090     methodOop method = instanceKlass::cast(klass)->find_method(name, signature);
  1091     if (method != NULL) return method;
  1092     klass = instanceKlass::cast(klass)->super();
  1094   return NULL;
  1097 // lookup a method in all the interfaces that this class implements
  1098 methodOop instanceKlass::lookup_method_in_all_interfaces(Symbol* name,
  1099                                                          Symbol* signature) const {
  1100   objArrayOop all_ifs = instanceKlass::cast(as_klassOop())->transitive_interfaces();
  1101   int num_ifs = all_ifs->length();
  1102   instanceKlass *ik = NULL;
  1103   for (int i = 0; i < num_ifs; i++) {
  1104     ik = instanceKlass::cast(klassOop(all_ifs->obj_at(i)));
  1105     methodOop m = ik->lookup_method(name, signature);
  1106     if (m != NULL) {
  1107       return m;
  1110   return NULL;
  1113 /* jni_id_for_impl for jfieldIds only */
  1114 JNIid* instanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
  1115   MutexLocker ml(JfieldIdCreation_lock);
  1116   // Retry lookup after we got the lock
  1117   JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
  1118   if (probe == NULL) {
  1119     // Slow case, allocate new static field identifier
  1120     probe = new JNIid(this_oop->as_klassOop(), offset, this_oop->jni_ids());
  1121     this_oop->set_jni_ids(probe);
  1123   return probe;
  1127 /* jni_id_for for jfieldIds only */
  1128 JNIid* instanceKlass::jni_id_for(int offset) {
  1129   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
  1130   if (probe == NULL) {
  1131     probe = jni_id_for_impl(this->as_klassOop(), offset);
  1133   return probe;
  1136 u2 instanceKlass::enclosing_method_data(int offset) {
  1137   typeArrayOop inner_class_list = inner_classes();
  1138   if (inner_class_list == NULL) {
  1139     return 0;
  1141   int length = inner_class_list->length();
  1142   if (length % inner_class_next_offset == 0) {
  1143     return 0;
  1144   } else {
  1145     int index = length - enclosing_method_attribute_size;
  1146     typeArrayHandle inner_class_list_h(inner_class_list);
  1147     assert(offset < enclosing_method_attribute_size, "invalid offset");
  1148     return inner_class_list_h->ushort_at(index + offset);
  1152 void instanceKlass::set_enclosing_method_indices(u2 class_index,
  1153                                                  u2 method_index) {
  1154   typeArrayOop inner_class_list = inner_classes();
  1155   assert (inner_class_list != NULL, "_inner_classes list is not set up");
  1156   int length = inner_class_list->length();
  1157   if (length % inner_class_next_offset == enclosing_method_attribute_size) {
  1158     int index = length - enclosing_method_attribute_size;
  1159     typeArrayHandle inner_class_list_h(inner_class_list);
  1160     inner_class_list_h->ushort_at_put(
  1161       index + enclosing_method_class_index_offset, class_index);
  1162     inner_class_list_h->ushort_at_put(
  1163       index + enclosing_method_method_index_offset, method_index);
  1167 // Lookup or create a jmethodID.
  1168 // This code is called by the VMThread and JavaThreads so the
  1169 // locking has to be done very carefully to avoid deadlocks
  1170 // and/or other cache consistency problems.
  1171 //
  1172 jmethodID instanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
  1173   size_t idnum = (size_t)method_h->method_idnum();
  1174   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
  1175   size_t length = 0;
  1176   jmethodID id = NULL;
  1178   // We use a double-check locking idiom here because this cache is
  1179   // performance sensitive. In the normal system, this cache only
  1180   // transitions from NULL to non-NULL which is safe because we use
  1181   // release_set_methods_jmethod_ids() to advertise the new cache.
  1182   // A partially constructed cache should never be seen by a racing
  1183   // thread. We also use release_store_ptr() to save a new jmethodID
  1184   // in the cache so a partially constructed jmethodID should never be
  1185   // seen either. Cache reads of existing jmethodIDs proceed without a
  1186   // lock, but cache writes of a new jmethodID requires uniqueness and
  1187   // creation of the cache itself requires no leaks so a lock is
  1188   // generally acquired in those two cases.
  1189   //
  1190   // If the RedefineClasses() API has been used, then this cache can
  1191   // grow and we'll have transitions from non-NULL to bigger non-NULL.
  1192   // Cache creation requires no leaks and we require safety between all
  1193   // cache accesses and freeing of the old cache so a lock is generally
  1194   // acquired when the RedefineClasses() API has been used.
  1196   if (jmeths != NULL) {
  1197     // the cache already exists
  1198     if (!ik_h->idnum_can_increment()) {
  1199       // the cache can't grow so we can just get the current values
  1200       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1201     } else {
  1202       // cache can grow so we have to be more careful
  1203       if (Threads::number_of_threads() == 0 ||
  1204           SafepointSynchronize::is_at_safepoint()) {
  1205         // we're single threaded or at a safepoint - no locking needed
  1206         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1207       } else {
  1208         MutexLocker ml(JmethodIdCreation_lock);
  1209         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
  1213   // implied else:
  1214   // we need to allocate a cache so default length and id values are good
  1216   if (jmeths == NULL ||   // no cache yet
  1217       length <= idnum ||  // cache is too short
  1218       id == NULL) {       // cache doesn't contain entry
  1220     // This function can be called by the VMThread so we have to do all
  1221     // things that might block on a safepoint before grabbing the lock.
  1222     // Otherwise, we can deadlock with the VMThread or have a cache
  1223     // consistency issue. These vars keep track of what we might have
  1224     // to free after the lock is dropped.
  1225     jmethodID  to_dealloc_id     = NULL;
  1226     jmethodID* to_dealloc_jmeths = NULL;
  1228     // may not allocate new_jmeths or use it if we allocate it
  1229     jmethodID* new_jmeths = NULL;
  1230     if (length <= idnum) {
  1231       // allocate a new cache that might be used
  1232       size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
  1233       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1);
  1234       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
  1235       // cache size is stored in element[0], other elements offset by one
  1236       new_jmeths[0] = (jmethodID)size;
  1239     // allocate a new jmethodID that might be used
  1240     jmethodID new_id = NULL;
  1241     if (method_h->is_old() && !method_h->is_obsolete()) {
  1242       // The method passed in is old (but not obsolete), we need to use the current version
  1243       methodOop current_method = ik_h->method_with_idnum((int)idnum);
  1244       assert(current_method != NULL, "old and but not obsolete, so should exist");
  1245       methodHandle current_method_h(current_method == NULL? method_h() : current_method);
  1246       new_id = JNIHandles::make_jmethod_id(current_method_h);
  1247     } else {
  1248       // It is the current version of the method or an obsolete method,
  1249       // use the version passed in
  1250       new_id = JNIHandles::make_jmethod_id(method_h);
  1253     if (Threads::number_of_threads() == 0 ||
  1254         SafepointSynchronize::is_at_safepoint()) {
  1255       // we're single threaded or at a safepoint - no locking needed
  1256       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
  1257                                           &to_dealloc_id, &to_dealloc_jmeths);
  1258     } else {
  1259       MutexLocker ml(JmethodIdCreation_lock);
  1260       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
  1261                                           &to_dealloc_id, &to_dealloc_jmeths);
  1264     // The lock has been dropped so we can free resources.
  1265     // Free up either the old cache or the new cache if we allocated one.
  1266     if (to_dealloc_jmeths != NULL) {
  1267       FreeHeap(to_dealloc_jmeths);
  1269     // free up the new ID since it wasn't needed
  1270     if (to_dealloc_id != NULL) {
  1271       JNIHandles::destroy_jmethod_id(to_dealloc_id);
  1274   return id;
  1278 // Common code to fetch the jmethodID from the cache or update the
  1279 // cache with the new jmethodID. This function should never do anything
  1280 // that causes the caller to go to a safepoint or we can deadlock with
  1281 // the VMThread or have cache consistency issues.
  1282 //
  1283 jmethodID instanceKlass::get_jmethod_id_fetch_or_update(
  1284             instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
  1285             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
  1286             jmethodID** to_dealloc_jmeths_p) {
  1287   assert(new_id != NULL, "sanity check");
  1288   assert(to_dealloc_id_p != NULL, "sanity check");
  1289   assert(to_dealloc_jmeths_p != NULL, "sanity check");
  1290   assert(Threads::number_of_threads() == 0 ||
  1291          SafepointSynchronize::is_at_safepoint() ||
  1292          JmethodIdCreation_lock->owned_by_self(), "sanity check");
  1294   // reacquire the cache - we are locked, single threaded or at a safepoint
  1295   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
  1296   jmethodID  id     = NULL;
  1297   size_t     length = 0;
  1299   if (jmeths == NULL ||                         // no cache yet
  1300       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
  1301     if (jmeths != NULL) {
  1302       // copy any existing entries from the old cache
  1303       for (size_t index = 0; index < length; index++) {
  1304         new_jmeths[index+1] = jmeths[index+1];
  1306       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
  1308     ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
  1309   } else {
  1310     // fetch jmethodID (if any) from the existing cache
  1311     id = jmeths[idnum+1];
  1312     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
  1314   if (id == NULL) {
  1315     // No matching jmethodID in the existing cache or we have a new
  1316     // cache or we just grew the cache. This cache write is done here
  1317     // by the first thread to win the foot race because a jmethodID
  1318     // needs to be unique once it is generally available.
  1319     id = new_id;
  1321     // The jmethodID cache can be read while unlocked so we have to
  1322     // make sure the new jmethodID is complete before installing it
  1323     // in the cache.
  1324     OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
  1325   } else {
  1326     *to_dealloc_id_p = new_id; // save new id for later delete
  1328   return id;
  1332 // Common code to get the jmethodID cache length and the jmethodID
  1333 // value at index idnum if there is one.
  1334 //
  1335 void instanceKlass::get_jmethod_id_length_value(jmethodID* cache,
  1336        size_t idnum, size_t *length_p, jmethodID* id_p) {
  1337   assert(cache != NULL, "sanity check");
  1338   assert(length_p != NULL, "sanity check");
  1339   assert(id_p != NULL, "sanity check");
  1341   // cache size is stored in element[0], other elements offset by one
  1342   *length_p = (size_t)cache[0];
  1343   if (*length_p <= idnum) {  // cache is too short
  1344     *id_p = NULL;
  1345   } else {
  1346     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
  1351 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
  1352 jmethodID instanceKlass::jmethod_id_or_null(methodOop method) {
  1353   size_t idnum = (size_t)method->method_idnum();
  1354   jmethodID* jmeths = methods_jmethod_ids_acquire();
  1355   size_t length;                                // length assigned as debugging crumb
  1356   jmethodID id = NULL;
  1357   if (jmeths != NULL &&                         // If there is a cache
  1358       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
  1359     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
  1361   return id;
  1365 // Cache an itable index
  1366 void instanceKlass::set_cached_itable_index(size_t idnum, int index) {
  1367   int* indices = methods_cached_itable_indices_acquire();
  1368   int* to_dealloc_indices = NULL;
  1370   // We use a double-check locking idiom here because this cache is
  1371   // performance sensitive. In the normal system, this cache only
  1372   // transitions from NULL to non-NULL which is safe because we use
  1373   // release_set_methods_cached_itable_indices() to advertise the
  1374   // new cache. A partially constructed cache should never be seen
  1375   // by a racing thread. Cache reads and writes proceed without a
  1376   // lock, but creation of the cache itself requires no leaks so a
  1377   // lock is generally acquired in that case.
  1378   //
  1379   // If the RedefineClasses() API has been used, then this cache can
  1380   // grow and we'll have transitions from non-NULL to bigger non-NULL.
  1381   // Cache creation requires no leaks and we require safety between all
  1382   // cache accesses and freeing of the old cache so a lock is generally
  1383   // acquired when the RedefineClasses() API has been used.
  1385   if (indices == NULL || idnum_can_increment()) {
  1386     // we need a cache or the cache can grow
  1387     MutexLocker ml(JNICachedItableIndex_lock);
  1388     // reacquire the cache to see if another thread already did the work
  1389     indices = methods_cached_itable_indices_acquire();
  1390     size_t length = 0;
  1391     // cache size is stored in element[0], other elements offset by one
  1392     if (indices == NULL || (length = (size_t)indices[0]) <= idnum) {
  1393       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
  1394       int* new_indices = NEW_C_HEAP_ARRAY(int, size+1);
  1395       new_indices[0] = (int)size;
  1396       // copy any existing entries
  1397       size_t i;
  1398       for (i = 0; i < length; i++) {
  1399         new_indices[i+1] = indices[i+1];
  1401       // Set all the rest to -1
  1402       for (i = length; i < size; i++) {
  1403         new_indices[i+1] = -1;
  1405       if (indices != NULL) {
  1406         // We have an old cache to delete so save it for after we
  1407         // drop the lock.
  1408         to_dealloc_indices = indices;
  1410       release_set_methods_cached_itable_indices(indices = new_indices);
  1413     if (idnum_can_increment()) {
  1414       // this cache can grow so we have to write to it safely
  1415       indices[idnum+1] = index;
  1417   } else {
  1418     CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
  1421   if (!idnum_can_increment()) {
  1422     // The cache cannot grow and this JNI itable index value does not
  1423     // have to be unique like a jmethodID. If there is a race to set it,
  1424     // it doesn't matter.
  1425     indices[idnum+1] = index;
  1428   if (to_dealloc_indices != NULL) {
  1429     // we allocated a new cache so free the old one
  1430     FreeHeap(to_dealloc_indices);
  1435 // Retrieve a cached itable index
  1436 int instanceKlass::cached_itable_index(size_t idnum) {
  1437   int* indices = methods_cached_itable_indices_acquire();
  1438   if (indices != NULL && ((size_t)indices[0]) > idnum) {
  1439      // indices exist and are long enough, retrieve possible cached
  1440     return indices[idnum+1];
  1442   return -1;
  1446 //
  1447 // Walk the list of dependent nmethods searching for nmethods which
  1448 // are dependent on the changes that were passed in and mark them for
  1449 // deoptimization.  Returns the number of nmethods found.
  1450 //
  1451 int instanceKlass::mark_dependent_nmethods(DepChange& changes) {
  1452   assert_locked_or_safepoint(CodeCache_lock);
  1453   int found = 0;
  1454   nmethodBucket* b = _dependencies;
  1455   while (b != NULL) {
  1456     nmethod* nm = b->get_nmethod();
  1457     // since dependencies aren't removed until an nmethod becomes a zombie,
  1458     // the dependency list may contain nmethods which aren't alive.
  1459     if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
  1460       if (TraceDependencies) {
  1461         ResourceMark rm;
  1462         tty->print_cr("Marked for deoptimization");
  1463         tty->print_cr("  context = %s", this->external_name());
  1464         changes.print();
  1465         nm->print();
  1466         nm->print_dependencies();
  1468       nm->mark_for_deoptimization();
  1469       found++;
  1471     b = b->next();
  1473   return found;
  1477 //
  1478 // Add an nmethodBucket to the list of dependencies for this nmethod.
  1479 // It's possible that an nmethod has multiple dependencies on this klass
  1480 // so a count is kept for each bucket to guarantee that creation and
  1481 // deletion of dependencies is consistent.
  1482 //
  1483 void instanceKlass::add_dependent_nmethod(nmethod* nm) {
  1484   assert_locked_or_safepoint(CodeCache_lock);
  1485   nmethodBucket* b = _dependencies;
  1486   nmethodBucket* last = NULL;
  1487   while (b != NULL) {
  1488     if (nm == b->get_nmethod()) {
  1489       b->increment();
  1490       return;
  1492     b = b->next();
  1494   _dependencies = new nmethodBucket(nm, _dependencies);
  1498 //
  1499 // Decrement count of the nmethod in the dependency list and remove
  1500 // the bucket competely when the count goes to 0.  This method must
  1501 // find a corresponding bucket otherwise there's a bug in the
  1502 // recording of dependecies.
  1503 //
  1504 void instanceKlass::remove_dependent_nmethod(nmethod* nm) {
  1505   assert_locked_or_safepoint(CodeCache_lock);
  1506   nmethodBucket* b = _dependencies;
  1507   nmethodBucket* last = NULL;
  1508   while (b != NULL) {
  1509     if (nm == b->get_nmethod()) {
  1510       if (b->decrement() == 0) {
  1511         if (last == NULL) {
  1512           _dependencies = b->next();
  1513         } else {
  1514           last->set_next(b->next());
  1516         delete b;
  1518       return;
  1520     last = b;
  1521     b = b->next();
  1523 #ifdef ASSERT
  1524   tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
  1525   nm->print();
  1526 #endif // ASSERT
  1527   ShouldNotReachHere();
  1531 #ifndef PRODUCT
  1532 void instanceKlass::print_dependent_nmethods(bool verbose) {
  1533   nmethodBucket* b = _dependencies;
  1534   int idx = 0;
  1535   while (b != NULL) {
  1536     nmethod* nm = b->get_nmethod();
  1537     tty->print("[%d] count=%d { ", idx++, b->count());
  1538     if (!verbose) {
  1539       nm->print_on(tty, "nmethod");
  1540       tty->print_cr(" } ");
  1541     } else {
  1542       nm->print();
  1543       nm->print_dependencies();
  1544       tty->print_cr("--- } ");
  1546     b = b->next();
  1551 bool instanceKlass::is_dependent_nmethod(nmethod* nm) {
  1552   nmethodBucket* b = _dependencies;
  1553   while (b != NULL) {
  1554     if (nm == b->get_nmethod()) {
  1555       return true;
  1557     b = b->next();
  1559   return false;
  1561 #endif //PRODUCT
  1564 #ifdef ASSERT
  1565 template <class T> void assert_is_in(T *p) {
  1566   T heap_oop = oopDesc::load_heap_oop(p);
  1567   if (!oopDesc::is_null(heap_oop)) {
  1568     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1569     assert(Universe::heap()->is_in(o), "should be in heap");
  1572 template <class T> void assert_is_in_closed_subset(T *p) {
  1573   T heap_oop = oopDesc::load_heap_oop(p);
  1574   if (!oopDesc::is_null(heap_oop)) {
  1575     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1576     assert(Universe::heap()->is_in_closed_subset(o), "should be in closed");
  1579 template <class T> void assert_is_in_reserved(T *p) {
  1580   T heap_oop = oopDesc::load_heap_oop(p);
  1581   if (!oopDesc::is_null(heap_oop)) {
  1582     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1583     assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
  1586 template <class T> void assert_nothing(T *p) {}
  1588 #else
  1589 template <class T> void assert_is_in(T *p) {}
  1590 template <class T> void assert_is_in_closed_subset(T *p) {}
  1591 template <class T> void assert_is_in_reserved(T *p) {}
  1592 template <class T> void assert_nothing(T *p) {}
  1593 #endif // ASSERT
  1595 //
  1596 // Macros that iterate over areas of oops which are specialized on type of
  1597 // oop pointer either narrow or wide, depending on UseCompressedOops
  1598 //
  1599 // Parameters are:
  1600 //   T         - type of oop to point to (either oop or narrowOop)
  1601 //   start_p   - starting pointer for region to iterate over
  1602 //   count     - number of oops or narrowOops to iterate over
  1603 //   do_oop    - action to perform on each oop (it's arbitrary C code which
  1604 //               makes it more efficient to put in a macro rather than making
  1605 //               it a template function)
  1606 //   assert_fn - assert function which is template function because performance
  1607 //               doesn't matter when enabled.
  1608 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
  1609   T, start_p, count, do_oop,                \
  1610   assert_fn)                                \
  1611 {                                           \
  1612   T* p         = (T*)(start_p);             \
  1613   T* const end = p + (count);               \
  1614   while (p < end) {                         \
  1615     (assert_fn)(p);                         \
  1616     do_oop;                                 \
  1617     ++p;                                    \
  1618   }                                         \
  1621 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
  1622   T, start_p, count, do_oop,                \
  1623   assert_fn)                                \
  1624 {                                           \
  1625   T* const start = (T*)(start_p);           \
  1626   T*       p     = start + (count);         \
  1627   while (start < p) {                       \
  1628     --p;                                    \
  1629     (assert_fn)(p);                         \
  1630     do_oop;                                 \
  1631   }                                         \
  1634 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
  1635   T, start_p, count, low, high,             \
  1636   do_oop, assert_fn)                        \
  1637 {                                           \
  1638   T* const l = (T*)(low);                   \
  1639   T* const h = (T*)(high);                  \
  1640   assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
  1641          mask_bits((intptr_t)h, sizeof(T)-1) == 0,   \
  1642          "bounded region must be properly aligned"); \
  1643   T* p       = (T*)(start_p);               \
  1644   T* end     = p + (count);                 \
  1645   if (p < l) p = l;                         \
  1646   if (end > h) end = h;                     \
  1647   while (p < end) {                         \
  1648     (assert_fn)(p);                         \
  1649     do_oop;                                 \
  1650     ++p;                                    \
  1651   }                                         \
  1655 // The following macros call specialized macros, passing either oop or
  1656 // narrowOop as the specialization type.  These test the UseCompressedOops
  1657 // flag.
  1658 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn)            \
  1659 {                                                                        \
  1660   /* Compute oopmap block range. The common case                         \
  1661      is nonstatic_oop_map_size == 1. */                                  \
  1662   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  1663   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
  1664   if (UseCompressedOops) {                                               \
  1665     while (map < end_map) {                                              \
  1666       InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop,                   \
  1667         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  1668         do_oop, assert_fn)                                               \
  1669       ++map;                                                             \
  1670     }                                                                    \
  1671   } else {                                                               \
  1672     while (map < end_map) {                                              \
  1673       InstanceKlass_SPECIALIZED_OOP_ITERATE(oop,                         \
  1674         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  1675         do_oop, assert_fn)                                               \
  1676       ++map;                                                             \
  1677     }                                                                    \
  1678   }                                                                      \
  1681 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn)    \
  1682 {                                                                        \
  1683   OopMapBlock* const start_map = start_of_nonstatic_oop_maps();          \
  1684   OopMapBlock* map             = start_map + nonstatic_oop_map_count();  \
  1685   if (UseCompressedOops) {                                               \
  1686     while (start_map < map) {                                            \
  1687       --map;                                                             \
  1688       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop,           \
  1689         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  1690         do_oop, assert_fn)                                               \
  1691     }                                                                    \
  1692   } else {                                                               \
  1693     while (start_map < map) {                                            \
  1694       --map;                                                             \
  1695       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop,                 \
  1696         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  1697         do_oop, assert_fn)                                               \
  1698     }                                                                    \
  1699   }                                                                      \
  1702 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop,    \
  1703                                               assert_fn)                 \
  1704 {                                                                        \
  1705   /* Compute oopmap block range. The common case is                      \
  1706      nonstatic_oop_map_size == 1, so we accept the                       \
  1707      usually non-existent extra overhead of examining                    \
  1708      all the maps. */                                                    \
  1709   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  1710   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
  1711   if (UseCompressedOops) {                                               \
  1712     while (map < end_map) {                                              \
  1713       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop,           \
  1714         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
  1715         low, high,                                                       \
  1716         do_oop, assert_fn)                                               \
  1717       ++map;                                                             \
  1718     }                                                                    \
  1719   } else {                                                               \
  1720     while (map < end_map) {                                              \
  1721       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop,                 \
  1722         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
  1723         low, high,                                                       \
  1724         do_oop, assert_fn)                                               \
  1725       ++map;                                                             \
  1726     }                                                                    \
  1727   }                                                                      \
  1730 void instanceKlass::oop_follow_contents(oop obj) {
  1731   assert(obj != NULL, "can't follow the content of NULL object");
  1732   obj->follow_header();
  1733   InstanceKlass_OOP_MAP_ITERATE( \
  1734     obj, \
  1735     MarkSweep::mark_and_push(p), \
  1736     assert_is_in_closed_subset)
  1739 #ifndef SERIALGC
  1740 void instanceKlass::oop_follow_contents(ParCompactionManager* cm,
  1741                                         oop obj) {
  1742   assert(obj != NULL, "can't follow the content of NULL object");
  1743   obj->follow_header(cm);
  1744   InstanceKlass_OOP_MAP_ITERATE( \
  1745     obj, \
  1746     PSParallelCompact::mark_and_push(cm, p), \
  1747     assert_is_in)
  1749 #endif // SERIALGC
  1751 // closure's do_header() method dicates whether the given closure should be
  1752 // applied to the klass ptr in the object header.
  1754 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)        \
  1756 int instanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
  1757   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  1758   /* header */                                                          \
  1759   if (closure->do_header()) {                                           \
  1760     obj->oop_iterate_header(closure);                                   \
  1761   }                                                                     \
  1762   InstanceKlass_OOP_MAP_ITERATE(                                        \
  1763     obj,                                                                \
  1764     SpecializationStats::                                               \
  1765       record_do_oop_call##nv_suffix(SpecializationStats::ik);           \
  1766     (closure)->do_oop##nv_suffix(p),                                    \
  1767     assert_is_in_closed_subset)                                         \
  1768   return size_helper();                                                 \
  1771 #ifndef SERIALGC
  1772 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
  1774 int instanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj,                \
  1775                                               OopClosureType* closure) {        \
  1776   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
  1777   /* header */                                                                  \
  1778   if (closure->do_header()) {                                                   \
  1779     obj->oop_iterate_header(closure);                                           \
  1780   }                                                                             \
  1781   /* instance variables */                                                      \
  1782   InstanceKlass_OOP_MAP_REVERSE_ITERATE(                                        \
  1783     obj,                                                                        \
  1784     SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
  1785     (closure)->do_oop##nv_suffix(p),                                            \
  1786     assert_is_in_closed_subset)                                                 \
  1787    return size_helper();                                                        \
  1789 #endif // !SERIALGC
  1791 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
  1793 int instanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj,              \
  1794                                                   OopClosureType* closure, \
  1795                                                   MemRegion mr) {          \
  1796   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  1797   if (closure->do_header()) {                                            \
  1798     obj->oop_iterate_header(closure, mr);                                \
  1799   }                                                                      \
  1800   InstanceKlass_BOUNDED_OOP_MAP_ITERATE(                                 \
  1801     obj, mr.start(), mr.end(),                                           \
  1802     (closure)->do_oop##nv_suffix(p),                                     \
  1803     assert_is_in_closed_subset)                                          \
  1804   return size_helper();                                                  \
  1807 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
  1808 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
  1809 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
  1810 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
  1811 #ifndef SERIALGC
  1812 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
  1813 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
  1814 #endif // !SERIALGC
  1816 int instanceKlass::oop_adjust_pointers(oop obj) {
  1817   int size = size_helper();
  1818   InstanceKlass_OOP_MAP_ITERATE( \
  1819     obj, \
  1820     MarkSweep::adjust_pointer(p), \
  1821     assert_is_in)
  1822   obj->adjust_header();
  1823   return size;
  1826 #ifndef SERIALGC
  1827 void instanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
  1828   InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
  1829     obj, \
  1830     if (PSScavenge::should_scavenge(p)) { \
  1831       pm->claim_or_forward_depth(p); \
  1832     }, \
  1833     assert_nothing )
  1836 int instanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
  1837   InstanceKlass_OOP_MAP_ITERATE( \
  1838     obj, \
  1839     PSParallelCompact::adjust_pointer(p), \
  1840     assert_nothing)
  1841   return size_helper();
  1844 #endif // SERIALGC
  1846 // This klass is alive but the implementor link is not followed/updated.
  1847 // Subklass and sibling links are handled by Klass::follow_weak_klass_links
  1849 void instanceKlass::follow_weak_klass_links(
  1850   BoolObjectClosure* is_alive, OopClosure* keep_alive) {
  1851   assert(is_alive->do_object_b(as_klassOop()), "this oop should be live");
  1852   if (ClassUnloading) {
  1853     for (int i = 0; i < implementors_limit; i++) {
  1854       klassOop impl = _implementors[i];
  1855       if (impl == NULL)  break;  // no more in the list
  1856       if (!is_alive->do_object_b(impl)) {
  1857         // remove this guy from the list by overwriting him with the tail
  1858         int lasti = --_nof_implementors;
  1859         assert(lasti >= i && lasti < implementors_limit, "just checking");
  1860         _implementors[i] = _implementors[lasti];
  1861         _implementors[lasti] = NULL;
  1862         --i; // rerun the loop at this index
  1865   } else {
  1866     for (int i = 0; i < implementors_limit; i++) {
  1867       keep_alive->do_oop(&adr_implementors()[i]);
  1870   Klass::follow_weak_klass_links(is_alive, keep_alive);
  1873 void instanceKlass::remove_unshareable_info() {
  1874   Klass::remove_unshareable_info();
  1875   init_implementor();
  1878 static void clear_all_breakpoints(methodOop m) {
  1879   m->clear_all_breakpoints();
  1882 void instanceKlass::release_C_heap_structures() {
  1883   // Deallocate oop map cache
  1884   if (_oop_map_cache != NULL) {
  1885     delete _oop_map_cache;
  1886     _oop_map_cache = NULL;
  1889   // Deallocate JNI identifiers for jfieldIDs
  1890   JNIid::deallocate(jni_ids());
  1891   set_jni_ids(NULL);
  1893   jmethodID* jmeths = methods_jmethod_ids_acquire();
  1894   if (jmeths != (jmethodID*)NULL) {
  1895     release_set_methods_jmethod_ids(NULL);
  1896     FreeHeap(jmeths);
  1899   int* indices = methods_cached_itable_indices_acquire();
  1900   if (indices != (int*)NULL) {
  1901     release_set_methods_cached_itable_indices(NULL);
  1902     FreeHeap(indices);
  1905   // release dependencies
  1906   nmethodBucket* b = _dependencies;
  1907   _dependencies = NULL;
  1908   while (b != NULL) {
  1909     nmethodBucket* next = b->next();
  1910     delete b;
  1911     b = next;
  1914   // Deallocate breakpoint records
  1915   if (breakpoints() != 0x0) {
  1916     methods_do(clear_all_breakpoints);
  1917     assert(breakpoints() == 0x0, "should have cleared breakpoints");
  1920   // deallocate information about previous versions
  1921   if (_previous_versions != NULL) {
  1922     for (int i = _previous_versions->length() - 1; i >= 0; i--) {
  1923       PreviousVersionNode * pv_node = _previous_versions->at(i);
  1924       delete pv_node;
  1926     delete _previous_versions;
  1927     _previous_versions = NULL;
  1930   // deallocate the cached class file
  1931   if (_cached_class_file_bytes != NULL) {
  1932     os::free(_cached_class_file_bytes);
  1933     _cached_class_file_bytes = NULL;
  1934     _cached_class_file_len = 0;
  1937   // Decrement symbol reference counts associated with the unloaded class.
  1938   if (_name != NULL) _name->decrement_refcount();
  1939   // unreference array name derived from this class name (arrays of an unloaded
  1940   // class can't be referenced anymore).
  1941   if (_array_name != NULL)  _array_name->decrement_refcount();
  1942   if (_source_file_name != NULL) _source_file_name->decrement_refcount();
  1943   if (_source_debug_extension != NULL) _source_debug_extension->decrement_refcount();
  1944   // walk constant pool and decrement symbol reference counts
  1945   _constants->unreference_symbols();
  1948 void instanceKlass::set_source_file_name(Symbol* n) {
  1949   _source_file_name = n;
  1950   if (_source_file_name != NULL) _source_file_name->increment_refcount();
  1953 void instanceKlass::set_source_debug_extension(Symbol* n) {
  1954   _source_debug_extension = n;
  1955   if (_source_debug_extension != NULL) _source_debug_extension->increment_refcount();
  1958 address instanceKlass::static_field_addr(int offset) {
  1959   return (address)(offset + instanceMirrorKlass::offset_of_static_fields() + (intptr_t)java_mirror());
  1963 const char* instanceKlass::signature_name() const {
  1964   const char* src = (const char*) (name()->as_C_string());
  1965   const int src_length = (int)strlen(src);
  1966   char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
  1967   int src_index = 0;
  1968   int dest_index = 0;
  1969   dest[dest_index++] = 'L';
  1970   while (src_index < src_length) {
  1971     dest[dest_index++] = src[src_index++];
  1973   dest[dest_index++] = ';';
  1974   dest[dest_index] = '\0';
  1975   return dest;
  1978 // different verisons of is_same_class_package
  1979 bool instanceKlass::is_same_class_package(klassOop class2) {
  1980   klassOop class1 = as_klassOop();
  1981   oop classloader1 = instanceKlass::cast(class1)->class_loader();
  1982   Symbol* classname1 = Klass::cast(class1)->name();
  1984   if (Klass::cast(class2)->oop_is_objArray()) {
  1985     class2 = objArrayKlass::cast(class2)->bottom_klass();
  1987   oop classloader2;
  1988   if (Klass::cast(class2)->oop_is_instance()) {
  1989     classloader2 = instanceKlass::cast(class2)->class_loader();
  1990   } else {
  1991     assert(Klass::cast(class2)->oop_is_typeArray(), "should be type array");
  1992     classloader2 = NULL;
  1994   Symbol* classname2 = Klass::cast(class2)->name();
  1996   return instanceKlass::is_same_class_package(classloader1, classname1,
  1997                                               classloader2, classname2);
  2000 bool instanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
  2001   klassOop class1 = as_klassOop();
  2002   oop classloader1 = instanceKlass::cast(class1)->class_loader();
  2003   Symbol* classname1 = Klass::cast(class1)->name();
  2005   return instanceKlass::is_same_class_package(classloader1, classname1,
  2006                                               classloader2, classname2);
  2009 // return true if two classes are in the same package, classloader
  2010 // and classname information is enough to determine a class's package
  2011 bool instanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
  2012                                           oop class_loader2, Symbol* class_name2) {
  2013   if (class_loader1 != class_loader2) {
  2014     return false;
  2015   } else if (class_name1 == class_name2) {
  2016     return true;                // skip painful bytewise comparison
  2017   } else {
  2018     ResourceMark rm;
  2020     // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
  2021     // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
  2022     // Otherwise, we just compare jbyte values between the strings.
  2023     const jbyte *name1 = class_name1->base();
  2024     const jbyte *name2 = class_name2->base();
  2026     const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
  2027     const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
  2029     if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
  2030       // One of the two doesn't have a package.  Only return true
  2031       // if the other one also doesn't have a package.
  2032       return last_slash1 == last_slash2;
  2033     } else {
  2034       // Skip over '['s
  2035       if (*name1 == '[') {
  2036         do {
  2037           name1++;
  2038         } while (*name1 == '[');
  2039         if (*name1 != 'L') {
  2040           // Something is terribly wrong.  Shouldn't be here.
  2041           return false;
  2044       if (*name2 == '[') {
  2045         do {
  2046           name2++;
  2047         } while (*name2 == '[');
  2048         if (*name2 != 'L') {
  2049           // Something is terribly wrong.  Shouldn't be here.
  2050           return false;
  2054       // Check that package part is identical
  2055       int length1 = last_slash1 - name1;
  2056       int length2 = last_slash2 - name2;
  2058       return UTF8::equal(name1, length1, name2, length2);
  2063 // Returns true iff super_method can be overridden by a method in targetclassname
  2064 // See JSL 3rd edition 8.4.6.1
  2065 // Assumes name-signature match
  2066 // "this" is instanceKlass of super_method which must exist
  2067 // note that the instanceKlass of the method in the targetclassname has not always been created yet
  2068 bool instanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
  2069    // Private methods can not be overridden
  2070    if (super_method->is_private()) {
  2071      return false;
  2073    // If super method is accessible, then override
  2074    if ((super_method->is_protected()) ||
  2075        (super_method->is_public())) {
  2076      return true;
  2078    // Package-private methods are not inherited outside of package
  2079    assert(super_method->is_package_private(), "must be package private");
  2080    return(is_same_class_package(targetclassloader(), targetclassname));
  2083 /* defined for now in jvm.cpp, for historical reasons *--
  2084 klassOop instanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
  2085                                                      Symbol*& simple_name_result, TRAPS) {
  2086   ...
  2088 */
  2090 // tell if two classes have the same enclosing class (at package level)
  2091 bool instanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
  2092                                                 klassOop class2_oop, TRAPS) {
  2093   if (class2_oop == class1->as_klassOop())          return true;
  2094   if (!Klass::cast(class2_oop)->oop_is_instance())  return false;
  2095   instanceKlassHandle class2(THREAD, class2_oop);
  2097   // must be in same package before we try anything else
  2098   if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
  2099     return false;
  2101   // As long as there is an outer1.getEnclosingClass,
  2102   // shift the search outward.
  2103   instanceKlassHandle outer1 = class1;
  2104   for (;;) {
  2105     // As we walk along, look for equalities between outer1 and class2.
  2106     // Eventually, the walks will terminate as outer1 stops
  2107     // at the top-level class around the original class.
  2108     bool ignore_inner_is_member;
  2109     klassOop next = outer1->compute_enclosing_class(&ignore_inner_is_member,
  2110                                                     CHECK_false);
  2111     if (next == NULL)  break;
  2112     if (next == class2())  return true;
  2113     outer1 = instanceKlassHandle(THREAD, next);
  2116   // Now do the same for class2.
  2117   instanceKlassHandle outer2 = class2;
  2118   for (;;) {
  2119     bool ignore_inner_is_member;
  2120     klassOop next = outer2->compute_enclosing_class(&ignore_inner_is_member,
  2121                                                     CHECK_false);
  2122     if (next == NULL)  break;
  2123     // Might as well check the new outer against all available values.
  2124     if (next == class1())  return true;
  2125     if (next == outer1())  return true;
  2126     outer2 = instanceKlassHandle(THREAD, next);
  2129   // If by this point we have not found an equality between the
  2130   // two classes, we know they are in separate package members.
  2131   return false;
  2135 jint instanceKlass::compute_modifier_flags(TRAPS) const {
  2136   klassOop k = as_klassOop();
  2137   jint access = access_flags().as_int();
  2139   // But check if it happens to be member class.
  2140   instanceKlassHandle ik(THREAD, k);
  2141   InnerClassesIterator iter(ik);
  2142   for (; !iter.done(); iter.next()) {
  2143     int ioff = iter.inner_class_info_index();
  2144     // Inner class attribute can be zero, skip it.
  2145     // Strange but true:  JVM spec. allows null inner class refs.
  2146     if (ioff == 0) continue;
  2148     // only look at classes that are already loaded
  2149     // since we are looking for the flags for our self.
  2150     Symbol* inner_name = ik->constants()->klass_name_at(ioff);
  2151     if ((ik->name() == inner_name)) {
  2152       // This is really a member class.
  2153       access = iter.inner_access_flags();
  2154       break;
  2157   // Remember to strip ACC_SUPER bit
  2158   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
  2161 jint instanceKlass::jvmti_class_status() const {
  2162   jint result = 0;
  2164   if (is_linked()) {
  2165     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
  2168   if (is_initialized()) {
  2169     assert(is_linked(), "Class status is not consistent");
  2170     result |= JVMTI_CLASS_STATUS_INITIALIZED;
  2172   if (is_in_error_state()) {
  2173     result |= JVMTI_CLASS_STATUS_ERROR;
  2175   return result;
  2178 methodOop instanceKlass::method_at_itable(klassOop holder, int index, TRAPS) {
  2179   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
  2180   int method_table_offset_in_words = ioe->offset()/wordSize;
  2181   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
  2182                        / itableOffsetEntry::size();
  2184   for (int cnt = 0 ; ; cnt ++, ioe ++) {
  2185     // If the interface isn't implemented by the receiver class,
  2186     // the VM should throw IncompatibleClassChangeError.
  2187     if (cnt >= nof_interfaces) {
  2188       THROW_0(vmSymbols::java_lang_IncompatibleClassChangeError());
  2191     klassOop ik = ioe->interface_klass();
  2192     if (ik == holder) break;
  2195   itableMethodEntry* ime = ioe->first_method_entry(as_klassOop());
  2196   methodOop m = ime[index].method();
  2197   if (m == NULL) {
  2198     THROW_0(vmSymbols::java_lang_AbstractMethodError());
  2200   return m;
  2203 // On-stack replacement stuff
  2204 void instanceKlass::add_osr_nmethod(nmethod* n) {
  2205   // only one compilation can be active
  2206   NEEDS_CLEANUP
  2207   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2208   OsrList_lock->lock_without_safepoint_check();
  2209   assert(n->is_osr_method(), "wrong kind of nmethod");
  2210   n->set_osr_link(osr_nmethods_head());
  2211   set_osr_nmethods_head(n);
  2212   // Raise the highest osr level if necessary
  2213   if (TieredCompilation) {
  2214     methodOop m = n->method();
  2215     m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
  2217   // Remember to unlock again
  2218   OsrList_lock->unlock();
  2220   // Get rid of the osr methods for the same bci that have lower levels.
  2221   if (TieredCompilation) {
  2222     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
  2223       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
  2224       if (inv != NULL && inv->is_in_use()) {
  2225         inv->make_not_entrant();
  2232 void instanceKlass::remove_osr_nmethod(nmethod* n) {
  2233   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2234   OsrList_lock->lock_without_safepoint_check();
  2235   assert(n->is_osr_method(), "wrong kind of nmethod");
  2236   nmethod* last = NULL;
  2237   nmethod* cur  = osr_nmethods_head();
  2238   int max_level = CompLevel_none;  // Find the max comp level excluding n
  2239   methodOop m = n->method();
  2240   // Search for match
  2241   while(cur != NULL && cur != n) {
  2242     if (TieredCompilation) {
  2243       // Find max level before n
  2244       max_level = MAX2(max_level, cur->comp_level());
  2246     last = cur;
  2247     cur = cur->osr_link();
  2249   nmethod* next = NULL;
  2250   if (cur == n) {
  2251     next = cur->osr_link();
  2252     if (last == NULL) {
  2253       // Remove first element
  2254       set_osr_nmethods_head(next);
  2255     } else {
  2256       last->set_osr_link(next);
  2259   n->set_osr_link(NULL);
  2260   if (TieredCompilation) {
  2261     cur = next;
  2262     while (cur != NULL) {
  2263       // Find max level after n
  2264       max_level = MAX2(max_level, cur->comp_level());
  2265       cur = cur->osr_link();
  2267     m->set_highest_osr_comp_level(max_level);
  2269   // Remember to unlock again
  2270   OsrList_lock->unlock();
  2273 nmethod* instanceKlass::lookup_osr_nmethod(const methodOop m, int bci, int comp_level, bool match_level) const {
  2274   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2275   OsrList_lock->lock_without_safepoint_check();
  2276   nmethod* osr = osr_nmethods_head();
  2277   nmethod* best = NULL;
  2278   while (osr != NULL) {
  2279     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
  2280     // There can be a time when a c1 osr method exists but we are waiting
  2281     // for a c2 version. When c2 completes its osr nmethod we will trash
  2282     // the c1 version and only be able to find the c2 version. However
  2283     // while we overflow in the c1 code at back branches we don't want to
  2284     // try and switch to the same code as we are already running
  2286     if (osr->method() == m &&
  2287         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
  2288       if (match_level) {
  2289         if (osr->comp_level() == comp_level) {
  2290           // Found a match - return it.
  2291           OsrList_lock->unlock();
  2292           return osr;
  2294       } else {
  2295         if (best == NULL || (osr->comp_level() > best->comp_level())) {
  2296           if (osr->comp_level() == CompLevel_highest_tier) {
  2297             // Found the best possible - return it.
  2298             OsrList_lock->unlock();
  2299             return osr;
  2301           best = osr;
  2305     osr = osr->osr_link();
  2307   OsrList_lock->unlock();
  2308   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
  2309     return best;
  2311   return NULL;
  2314 // -----------------------------------------------------------------------------------------------------
  2315 #ifndef PRODUCT
  2317 // Printing
  2319 #define BULLET  " - "
  2321 void FieldPrinter::do_field(fieldDescriptor* fd) {
  2322   _st->print(BULLET);
  2323    if (_obj == NULL) {
  2324      fd->print_on(_st);
  2325      _st->cr();
  2326    } else {
  2327      fd->print_on_for(_st, _obj);
  2328      _st->cr();
  2333 void instanceKlass::oop_print_on(oop obj, outputStream* st) {
  2334   Klass::oop_print_on(obj, st);
  2336   if (as_klassOop() == SystemDictionary::String_klass()) {
  2337     typeArrayOop value  = java_lang_String::value(obj);
  2338     juint        offset = java_lang_String::offset(obj);
  2339     juint        length = java_lang_String::length(obj);
  2340     if (value != NULL &&
  2341         value->is_typeArray() &&
  2342         offset          <= (juint) value->length() &&
  2343         offset + length <= (juint) value->length()) {
  2344       st->print(BULLET"string: ");
  2345       Handle h_obj(obj);
  2346       java_lang_String::print(h_obj, st);
  2347       st->cr();
  2348       if (!WizardMode)  return;  // that is enough
  2352   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
  2353   FieldPrinter print_field(st, obj);
  2354   do_nonstatic_fields(&print_field);
  2356   if (as_klassOop() == SystemDictionary::Class_klass()) {
  2357     st->print(BULLET"signature: ");
  2358     java_lang_Class::print_signature(obj, st);
  2359     st->cr();
  2360     klassOop mirrored_klass = java_lang_Class::as_klassOop(obj);
  2361     st->print(BULLET"fake entry for mirror: ");
  2362     mirrored_klass->print_value_on(st);
  2363     st->cr();
  2364     st->print(BULLET"fake entry resolved_constructor: ");
  2365     methodOop ctor = java_lang_Class::resolved_constructor(obj);
  2366     ctor->print_value_on(st);
  2367     klassOop array_klass = java_lang_Class::array_klass(obj);
  2368     st->cr();
  2369     st->print(BULLET"fake entry for array: ");
  2370     array_klass->print_value_on(st);
  2371     st->cr();
  2372     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
  2373     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
  2374     klassOop real_klass = java_lang_Class::as_klassOop(obj);
  2375     if (real_klass != NULL && real_klass->klass_part()->oop_is_instance()) {
  2376       instanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
  2378   } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
  2379     st->print(BULLET"signature: ");
  2380     java_lang_invoke_MethodType::print_signature(obj, st);
  2381     st->cr();
  2385 #endif //PRODUCT
  2387 void instanceKlass::oop_print_value_on(oop obj, outputStream* st) {
  2388   st->print("a ");
  2389   name()->print_value_on(st);
  2390   obj->print_address_on(st);
  2391   if (as_klassOop() == SystemDictionary::String_klass()
  2392       && java_lang_String::value(obj) != NULL) {
  2393     ResourceMark rm;
  2394     int len = java_lang_String::length(obj);
  2395     int plen = (len < 24 ? len : 12);
  2396     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
  2397     st->print(" = \"%s\"", str);
  2398     if (len > plen)
  2399       st->print("...[%d]", len);
  2400   } else if (as_klassOop() == SystemDictionary::Class_klass()) {
  2401     klassOop k = java_lang_Class::as_klassOop(obj);
  2402     st->print(" = ");
  2403     if (k != NULL) {
  2404       k->print_value_on(st);
  2405     } else {
  2406       const char* tname = type2name(java_lang_Class::primitive_type(obj));
  2407       st->print("%s", tname ? tname : "type?");
  2409   } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
  2410     st->print(" = ");
  2411     java_lang_invoke_MethodType::print_signature(obj, st);
  2412   } else if (java_lang_boxing_object::is_instance(obj)) {
  2413     st->print(" = ");
  2414     java_lang_boxing_object::print(obj, st);
  2418 const char* instanceKlass::internal_name() const {
  2419   return external_name();
  2422 // Verification
  2424 class VerifyFieldClosure: public OopClosure {
  2425  protected:
  2426   template <class T> void do_oop_work(T* p) {
  2427     guarantee(Universe::heap()->is_in_closed_subset(p), "should be in heap");
  2428     oop obj = oopDesc::load_decode_heap_oop(p);
  2429     if (!obj->is_oop_or_null()) {
  2430       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
  2431       Universe::print();
  2432       guarantee(false, "boom");
  2435  public:
  2436   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
  2437   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
  2438 };
  2440 void instanceKlass::oop_verify_on(oop obj, outputStream* st) {
  2441   Klass::oop_verify_on(obj, st);
  2442   VerifyFieldClosure blk;
  2443   oop_oop_iterate(obj, &blk);
  2446 // JNIid class for jfieldIDs only
  2447 // Note to reviewers:
  2448 // These JNI functions are just moved over to column 1 and not changed
  2449 // in the compressed oops workspace.
  2450 JNIid::JNIid(klassOop holder, int offset, JNIid* next) {
  2451   _holder = holder;
  2452   _offset = offset;
  2453   _next = next;
  2454   debug_only(_is_static_field_id = false;)
  2458 JNIid* JNIid::find(int offset) {
  2459   JNIid* current = this;
  2460   while (current != NULL) {
  2461     if (current->offset() == offset) return current;
  2462     current = current->next();
  2464   return NULL;
  2467 void JNIid::oops_do(OopClosure* f) {
  2468   for (JNIid* cur = this; cur != NULL; cur = cur->next()) {
  2469     f->do_oop(cur->holder_addr());
  2473 void JNIid::deallocate(JNIid* current) {
  2474   while (current != NULL) {
  2475     JNIid* next = current->next();
  2476     delete current;
  2477     current = next;
  2482 void JNIid::verify(klassOop holder) {
  2483   int first_field_offset  = instanceMirrorKlass::offset_of_static_fields();
  2484   int end_field_offset;
  2485   end_field_offset = first_field_offset + (instanceKlass::cast(holder)->static_field_size() * wordSize);
  2487   JNIid* current = this;
  2488   while (current != NULL) {
  2489     guarantee(current->holder() == holder, "Invalid klass in JNIid");
  2490 #ifdef ASSERT
  2491     int o = current->offset();
  2492     if (current->is_static_field_id()) {
  2493       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
  2495 #endif
  2496     current = current->next();
  2501 #ifdef ASSERT
  2502 void instanceKlass::set_init_state(ClassState state) {
  2503   bool good_state = as_klassOop()->is_shared() ? (_init_state <= state)
  2504                                                : (_init_state < state);
  2505   assert(good_state || state == allocated, "illegal state transition");
  2506   _init_state = (u1)state;
  2508 #endif
  2511 // RedefineClasses() support for previous versions:
  2513 // Add an information node that contains weak references to the
  2514 // interesting parts of the previous version of the_class.
  2515 // This is also where we clean out any unused weak references.
  2516 // Note that while we delete nodes from the _previous_versions
  2517 // array, we never delete the array itself until the klass is
  2518 // unloaded. The has_been_redefined() query depends on that fact.
  2519 //
  2520 void instanceKlass::add_previous_version(instanceKlassHandle ikh,
  2521        BitMap* emcp_methods, int emcp_method_count) {
  2522   assert(Thread::current()->is_VM_thread(),
  2523          "only VMThread can add previous versions");
  2525   if (_previous_versions == NULL) {
  2526     // This is the first previous version so make some space.
  2527     // Start with 2 elements under the assumption that the class
  2528     // won't be redefined much.
  2529     _previous_versions =  new (ResourceObj::C_HEAP)
  2530                             GrowableArray<PreviousVersionNode *>(2, true);
  2533   // RC_TRACE macro has an embedded ResourceMark
  2534   RC_TRACE(0x00000100, ("adding previous version ref for %s @%d, EMCP_cnt=%d",
  2535     ikh->external_name(), _previous_versions->length(), emcp_method_count));
  2536   constantPoolHandle cp_h(ikh->constants());
  2537   jobject cp_ref;
  2538   if (cp_h->is_shared()) {
  2539     // a shared ConstantPool requires a regular reference; a weak
  2540     // reference would be collectible
  2541     cp_ref = JNIHandles::make_global(cp_h);
  2542   } else {
  2543     cp_ref = JNIHandles::make_weak_global(cp_h);
  2545   PreviousVersionNode * pv_node = NULL;
  2546   objArrayOop old_methods = ikh->methods();
  2548   if (emcp_method_count == 0) {
  2549     // non-shared ConstantPool gets a weak reference
  2550     pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), NULL);
  2551     RC_TRACE(0x00000400,
  2552       ("add: all methods are obsolete; flushing any EMCP weak refs"));
  2553   } else {
  2554     int local_count = 0;
  2555     GrowableArray<jweak>* method_refs = new (ResourceObj::C_HEAP)
  2556       GrowableArray<jweak>(emcp_method_count, true);
  2557     for (int i = 0; i < old_methods->length(); i++) {
  2558       if (emcp_methods->at(i)) {
  2559         // this old method is EMCP so save a weak ref
  2560         methodOop old_method = (methodOop) old_methods->obj_at(i);
  2561         methodHandle old_method_h(old_method);
  2562         jweak method_ref = JNIHandles::make_weak_global(old_method_h);
  2563         method_refs->append(method_ref);
  2564         if (++local_count >= emcp_method_count) {
  2565           // no more EMCP methods so bail out now
  2566           break;
  2570     // non-shared ConstantPool gets a weak reference
  2571     pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), method_refs);
  2574   _previous_versions->append(pv_node);
  2576   // Using weak references allows the interesting parts of previous
  2577   // classes to be GC'ed when they are no longer needed. Since the
  2578   // caller is the VMThread and we are at a safepoint, this is a good
  2579   // time to clear out unused weak references.
  2581   RC_TRACE(0x00000400, ("add: previous version length=%d",
  2582     _previous_versions->length()));
  2584   // skip the last entry since we just added it
  2585   for (int i = _previous_versions->length() - 2; i >= 0; i--) {
  2586     // check the previous versions array for a GC'ed weak refs
  2587     pv_node = _previous_versions->at(i);
  2588     cp_ref = pv_node->prev_constant_pool();
  2589     assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
  2590     if (cp_ref == NULL) {
  2591       delete pv_node;
  2592       _previous_versions->remove_at(i);
  2593       // Since we are traversing the array backwards, we don't have to
  2594       // do anything special with the index.
  2595       continue;  // robustness
  2598     constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
  2599     if (cp == NULL) {
  2600       // this entry has been GC'ed so remove it
  2601       delete pv_node;
  2602       _previous_versions->remove_at(i);
  2603       // Since we are traversing the array backwards, we don't have to
  2604       // do anything special with the index.
  2605       continue;
  2606     } else {
  2607       RC_TRACE(0x00000400, ("add: previous version @%d is alive", i));
  2610     GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
  2611     if (method_refs != NULL) {
  2612       RC_TRACE(0x00000400, ("add: previous methods length=%d",
  2613         method_refs->length()));
  2614       for (int j = method_refs->length() - 1; j >= 0; j--) {
  2615         jweak method_ref = method_refs->at(j);
  2616         assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
  2617         if (method_ref == NULL) {
  2618           method_refs->remove_at(j);
  2619           // Since we are traversing the array backwards, we don't have to
  2620           // do anything special with the index.
  2621           continue;  // robustness
  2624         methodOop method = (methodOop)JNIHandles::resolve(method_ref);
  2625         if (method == NULL || emcp_method_count == 0) {
  2626           // This method entry has been GC'ed or the current
  2627           // RedefineClasses() call has made all methods obsolete
  2628           // so remove it.
  2629           JNIHandles::destroy_weak_global(method_ref);
  2630           method_refs->remove_at(j);
  2631         } else {
  2632           // RC_TRACE macro has an embedded ResourceMark
  2633           RC_TRACE(0x00000400,
  2634             ("add: %s(%s): previous method @%d in version @%d is alive",
  2635             method->name()->as_C_string(), method->signature()->as_C_string(),
  2636             j, i));
  2642   int obsolete_method_count = old_methods->length() - emcp_method_count;
  2644   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
  2645       _previous_versions->length() > 1) {
  2646     // We have a mix of obsolete and EMCP methods. If there is more
  2647     // than the previous version that we just added, then we have to
  2648     // clear out any matching EMCP method entries the hard way.
  2649     int local_count = 0;
  2650     for (int i = 0; i < old_methods->length(); i++) {
  2651       if (!emcp_methods->at(i)) {
  2652         // only obsolete methods are interesting
  2653         methodOop old_method = (methodOop) old_methods->obj_at(i);
  2654         Symbol* m_name = old_method->name();
  2655         Symbol* m_signature = old_method->signature();
  2657         // skip the last entry since we just added it
  2658         for (int j = _previous_versions->length() - 2; j >= 0; j--) {
  2659           // check the previous versions array for a GC'ed weak refs
  2660           pv_node = _previous_versions->at(j);
  2661           cp_ref = pv_node->prev_constant_pool();
  2662           assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
  2663           if (cp_ref == NULL) {
  2664             delete pv_node;
  2665             _previous_versions->remove_at(j);
  2666             // Since we are traversing the array backwards, we don't have to
  2667             // do anything special with the index.
  2668             continue;  // robustness
  2671           constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
  2672           if (cp == NULL) {
  2673             // this entry has been GC'ed so remove it
  2674             delete pv_node;
  2675             _previous_versions->remove_at(j);
  2676             // Since we are traversing the array backwards, we don't have to
  2677             // do anything special with the index.
  2678             continue;
  2681           GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
  2682           if (method_refs == NULL) {
  2683             // We have run into a PreviousVersion generation where
  2684             // all methods were made obsolete during that generation's
  2685             // RedefineClasses() operation. At the time of that
  2686             // operation, all EMCP methods were flushed so we don't
  2687             // have to go back any further.
  2688             //
  2689             // A NULL method_refs is different than an empty method_refs.
  2690             // We cannot infer any optimizations about older generations
  2691             // from an empty method_refs for the current generation.
  2692             break;
  2695           for (int k = method_refs->length() - 1; k >= 0; k--) {
  2696             jweak method_ref = method_refs->at(k);
  2697             assert(method_ref != NULL,
  2698               "weak method ref was unexpectedly cleared");
  2699             if (method_ref == NULL) {
  2700               method_refs->remove_at(k);
  2701               // Since we are traversing the array backwards, we don't
  2702               // have to do anything special with the index.
  2703               continue;  // robustness
  2706             methodOop method = (methodOop)JNIHandles::resolve(method_ref);
  2707             if (method == NULL) {
  2708               // this method entry has been GC'ed so skip it
  2709               JNIHandles::destroy_weak_global(method_ref);
  2710               method_refs->remove_at(k);
  2711               continue;
  2714             if (method->name() == m_name &&
  2715                 method->signature() == m_signature) {
  2716               // The current RedefineClasses() call has made all EMCP
  2717               // versions of this method obsolete so mark it as obsolete
  2718               // and remove the weak ref.
  2719               RC_TRACE(0x00000400,
  2720                 ("add: %s(%s): flush obsolete method @%d in version @%d",
  2721                 m_name->as_C_string(), m_signature->as_C_string(), k, j));
  2723               method->set_is_obsolete();
  2724               JNIHandles::destroy_weak_global(method_ref);
  2725               method_refs->remove_at(k);
  2726               break;
  2730           // The previous loop may not find a matching EMCP method, but
  2731           // that doesn't mean that we can optimize and not go any
  2732           // further back in the PreviousVersion generations. The EMCP
  2733           // method for this generation could have already been GC'ed,
  2734           // but there still may be an older EMCP method that has not
  2735           // been GC'ed.
  2738         if (++local_count >= obsolete_method_count) {
  2739           // no more obsolete methods so bail out now
  2740           break;
  2745 } // end add_previous_version()
  2748 // Determine if instanceKlass has a previous version.
  2749 bool instanceKlass::has_previous_version() const {
  2750   if (_previous_versions == NULL) {
  2751     // no previous versions array so answer is easy
  2752     return false;
  2755   for (int i = _previous_versions->length() - 1; i >= 0; i--) {
  2756     // Check the previous versions array for an info node that hasn't
  2757     // been GC'ed
  2758     PreviousVersionNode * pv_node = _previous_versions->at(i);
  2760     jobject cp_ref = pv_node->prev_constant_pool();
  2761     assert(cp_ref != NULL, "cp reference was unexpectedly cleared");
  2762     if (cp_ref == NULL) {
  2763       continue;  // robustness
  2766     constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
  2767     if (cp != NULL) {
  2768       // we have at least one previous version
  2769       return true;
  2772     // We don't have to check the method refs. If the constant pool has
  2773     // been GC'ed then so have the methods.
  2776   // all of the underlying nodes' info has been GC'ed
  2777   return false;
  2778 } // end has_previous_version()
  2780 methodOop instanceKlass::method_with_idnum(int idnum) {
  2781   methodOop m = NULL;
  2782   if (idnum < methods()->length()) {
  2783     m = (methodOop) methods()->obj_at(idnum);
  2785   if (m == NULL || m->method_idnum() != idnum) {
  2786     for (int index = 0; index < methods()->length(); ++index) {
  2787       m = (methodOop) methods()->obj_at(index);
  2788       if (m->method_idnum() == idnum) {
  2789         return m;
  2793   return m;
  2797 // Set the annotation at 'idnum' to 'anno'.
  2798 // We don't want to create or extend the array if 'anno' is NULL, since that is the
  2799 // default value.  However, if the array exists and is long enough, we must set NULL values.
  2800 void instanceKlass::set_methods_annotations_of(int idnum, typeArrayOop anno, objArrayOop* md_p) {
  2801   objArrayOop md = *md_p;
  2802   if (md != NULL && md->length() > idnum) {
  2803     md->obj_at_put(idnum, anno);
  2804   } else if (anno != NULL) {
  2805     // create the array
  2806     int length = MAX2(idnum+1, (int)_idnum_allocated_count);
  2807     md = oopFactory::new_system_objArray(length, Thread::current());
  2808     if (*md_p != NULL) {
  2809       // copy the existing entries
  2810       for (int index = 0; index < (*md_p)->length(); index++) {
  2811         md->obj_at_put(index, (*md_p)->obj_at(index));
  2814     set_annotations(md, md_p);
  2815     md->obj_at_put(idnum, anno);
  2816   } // if no array and idnum isn't included there is nothing to do
  2819 // Construct a PreviousVersionNode entry for the array hung off
  2820 // the instanceKlass.
  2821 PreviousVersionNode::PreviousVersionNode(jobject prev_constant_pool,
  2822   bool prev_cp_is_weak, GrowableArray<jweak>* prev_EMCP_methods) {
  2824   _prev_constant_pool = prev_constant_pool;
  2825   _prev_cp_is_weak = prev_cp_is_weak;
  2826   _prev_EMCP_methods = prev_EMCP_methods;
  2830 // Destroy a PreviousVersionNode
  2831 PreviousVersionNode::~PreviousVersionNode() {
  2832   if (_prev_constant_pool != NULL) {
  2833     if (_prev_cp_is_weak) {
  2834       JNIHandles::destroy_weak_global(_prev_constant_pool);
  2835     } else {
  2836       JNIHandles::destroy_global(_prev_constant_pool);
  2840   if (_prev_EMCP_methods != NULL) {
  2841     for (int i = _prev_EMCP_methods->length() - 1; i >= 0; i--) {
  2842       jweak method_ref = _prev_EMCP_methods->at(i);
  2843       if (method_ref != NULL) {
  2844         JNIHandles::destroy_weak_global(method_ref);
  2847     delete _prev_EMCP_methods;
  2852 // Construct a PreviousVersionInfo entry
  2853 PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
  2854   _prev_constant_pool_handle = constantPoolHandle();  // NULL handle
  2855   _prev_EMCP_method_handles = NULL;
  2857   jobject cp_ref = pv_node->prev_constant_pool();
  2858   assert(cp_ref != NULL, "constant pool ref was unexpectedly cleared");
  2859   if (cp_ref == NULL) {
  2860     return;  // robustness
  2863   constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
  2864   if (cp == NULL) {
  2865     // Weak reference has been GC'ed. Since the constant pool has been
  2866     // GC'ed, the methods have also been GC'ed.
  2867     return;
  2870   // make the constantPoolOop safe to return
  2871   _prev_constant_pool_handle = constantPoolHandle(cp);
  2873   GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
  2874   if (method_refs == NULL) {
  2875     // the instanceKlass did not have any EMCP methods
  2876     return;
  2879   _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
  2881   int n_methods = method_refs->length();
  2882   for (int i = 0; i < n_methods; i++) {
  2883     jweak method_ref = method_refs->at(i);
  2884     assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
  2885     if (method_ref == NULL) {
  2886       continue;  // robustness
  2889     methodOop method = (methodOop)JNIHandles::resolve(method_ref);
  2890     if (method == NULL) {
  2891       // this entry has been GC'ed so skip it
  2892       continue;
  2895     // make the methodOop safe to return
  2896     _prev_EMCP_method_handles->append(methodHandle(method));
  2901 // Destroy a PreviousVersionInfo
  2902 PreviousVersionInfo::~PreviousVersionInfo() {
  2903   // Since _prev_EMCP_method_handles is not C-heap allocated, we
  2904   // don't have to delete it.
  2908 // Construct a helper for walking the previous versions array
  2909 PreviousVersionWalker::PreviousVersionWalker(instanceKlass *ik) {
  2910   _previous_versions = ik->previous_versions();
  2911   _current_index = 0;
  2912   // _hm needs no initialization
  2913   _current_p = NULL;
  2917 // Destroy a PreviousVersionWalker
  2918 PreviousVersionWalker::~PreviousVersionWalker() {
  2919   // Delete the current info just in case the caller didn't walk to
  2920   // the end of the previous versions list. No harm if _current_p is
  2921   // already NULL.
  2922   delete _current_p;
  2924   // When _hm is destroyed, all the Handles returned in
  2925   // PreviousVersionInfo objects will be destroyed.
  2926   // Also, after this destructor is finished it will be
  2927   // safe to delete the GrowableArray allocated in the
  2928   // PreviousVersionInfo objects.
  2932 // Return the interesting information for the next previous version
  2933 // of the klass. Returns NULL if there are no more previous versions.
  2934 PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
  2935   if (_previous_versions == NULL) {
  2936     // no previous versions so nothing to return
  2937     return NULL;
  2940   delete _current_p;  // cleanup the previous info for the caller
  2941   _current_p = NULL;  // reset to NULL so we don't delete same object twice
  2943   int length = _previous_versions->length();
  2945   while (_current_index < length) {
  2946     PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
  2947     PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP)
  2948                                           PreviousVersionInfo(pv_node);
  2950     constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
  2951     if (cp_h.is_null()) {
  2952       delete pv_info;
  2954       // The underlying node's info has been GC'ed so try the next one.
  2955       // We don't have to check the methods. If the constant pool has
  2956       // GC'ed then so have the methods.
  2957       continue;
  2960     // Found a node with non GC'ed info so return it. The caller will
  2961     // need to delete pv_info when they are done with it.
  2962     _current_p = pv_info;
  2963     return pv_info;
  2966   // all of the underlying nodes' info has been GC'ed
  2967   return NULL;
  2968 } // end next_previous_version()

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