src/share/vm/oops/instanceKlass.cpp

Fri, 04 Sep 2009 12:53:02 -0400

author
acorn
date
Fri, 04 Sep 2009 12:53:02 -0400
changeset 1408
ad6585fd4087
parent 1399
75e30968ebe1
child 1409
26b774d693aa
permissions
-rw-r--r--

6830542: Performance: JVM_DefineClass already verified.
Reviewed-by: kamg, phh

     1 /*
     2  * Copyright 1997-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 # include "incls/_precompiled.incl"
    26 # include "incls/_instanceKlass.cpp.incl"
    28 bool instanceKlass::should_be_initialized() const {
    29   return !is_initialized();
    30 }
    32 klassVtable* instanceKlass::vtable() const {
    33   return new klassVtable(as_klassOop(), start_of_vtable(), vtable_length() / vtableEntry::size());
    34 }
    36 klassItable* instanceKlass::itable() const {
    37   return new klassItable(as_klassOop());
    38 }
    40 void instanceKlass::eager_initialize(Thread *thread) {
    41   if (!EagerInitialization) return;
    43   if (this->is_not_initialized()) {
    44     // abort if the the class has a class initializer
    45     if (this->class_initializer() != NULL) return;
    47     // abort if it is java.lang.Object (initialization is handled in genesis)
    48     klassOop super = this->super();
    49     if (super == NULL) return;
    51     // abort if the super class should be initialized
    52     if (!instanceKlass::cast(super)->is_initialized()) return;
    54     // call body to expose the this pointer
    55     instanceKlassHandle this_oop(thread, this->as_klassOop());
    56     eager_initialize_impl(this_oop);
    57   }
    58 }
    61 void instanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
    62   EXCEPTION_MARK;
    63   ObjectLocker ol(this_oop, THREAD);
    65   // abort if someone beat us to the initialization
    66   if (!this_oop->is_not_initialized()) return;  // note: not equivalent to is_initialized()
    68   ClassState old_state = this_oop->_init_state;
    69   link_class_impl(this_oop, true, THREAD);
    70   if (HAS_PENDING_EXCEPTION) {
    71     CLEAR_PENDING_EXCEPTION;
    72     // Abort if linking the class throws an exception.
    74     // Use a test to avoid redundantly resetting the state if there's
    75     // no change.  Set_init_state() asserts that state changes make
    76     // progress, whereas here we might just be spinning in place.
    77     if( old_state != this_oop->_init_state )
    78       this_oop->set_init_state (old_state);
    79   } else {
    80     // linking successfull, mark class as initialized
    81     this_oop->set_init_state (fully_initialized);
    82     // trace
    83     if (TraceClassInitialization) {
    84       ResourceMark rm(THREAD);
    85       tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
    86     }
    87   }
    88 }
    91 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
    92 // process. The step comments refers to the procedure described in that section.
    93 // Note: implementation moved to static method to expose the this pointer.
    94 void instanceKlass::initialize(TRAPS) {
    95   if (this->should_be_initialized()) {
    96     HandleMark hm(THREAD);
    97     instanceKlassHandle this_oop(THREAD, this->as_klassOop());
    98     initialize_impl(this_oop, CHECK);
    99     // Note: at this point the class may be initialized
   100     //       OR it may be in the state of being initialized
   101     //       in case of recursive initialization!
   102   } else {
   103     assert(is_initialized(), "sanity check");
   104   }
   105 }
   108 bool instanceKlass::verify_code(
   109     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
   110   // 1) Verify the bytecodes
   111   Verifier::Mode mode =
   112     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
   113   return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
   114 }
   117 // Used exclusively by the shared spaces dump mechanism to prevent
   118 // classes mapped into the shared regions in new VMs from appearing linked.
   120 void instanceKlass::unlink_class() {
   121   assert(is_linked(), "must be linked");
   122   _init_state = loaded;
   123 }
   125 void instanceKlass::link_class(TRAPS) {
   126   assert(is_loaded(), "must be loaded");
   127   if (!is_linked()) {
   128     instanceKlassHandle this_oop(THREAD, this->as_klassOop());
   129     link_class_impl(this_oop, true, CHECK);
   130   }
   131 }
   133 // Called to verify that a class can link during initialization, without
   134 // throwing a VerifyError.
   135 bool instanceKlass::link_class_or_fail(TRAPS) {
   136   assert(is_loaded(), "must be loaded");
   137   if (!is_linked()) {
   138     instanceKlassHandle this_oop(THREAD, this->as_klassOop());
   139     link_class_impl(this_oop, false, CHECK_false);
   140   }
   141   return is_linked();
   142 }
   144 bool instanceKlass::link_class_impl(
   145     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
   146   // check for error state
   147   if (this_oop->is_in_error_state()) {
   148     ResourceMark rm(THREAD);
   149     THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
   150                this_oop->external_name(), false);
   151   }
   152   // return if already verified
   153   if (this_oop->is_linked()) {
   154     return true;
   155   }
   157   // Timing
   158   // timer handles recursion
   159   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
   160   JavaThread* jt = (JavaThread*)THREAD;
   162   // link super class before linking this class
   163   instanceKlassHandle super(THREAD, this_oop->super());
   164   if (super.not_null()) {
   165     if (super->is_interface()) {  // check if super class is an interface
   166       ResourceMark rm(THREAD);
   167       Exceptions::fthrow(
   168         THREAD_AND_LOCATION,
   169         vmSymbolHandles::java_lang_IncompatibleClassChangeError(),
   170         "class %s has interface %s as super class",
   171         this_oop->external_name(),
   172         super->external_name()
   173       );
   174       return false;
   175     }
   177     link_class_impl(super, throw_verifyerror, CHECK_false);
   178   }
   180   // link all interfaces implemented by this class before linking this class
   181   objArrayHandle interfaces (THREAD, this_oop->local_interfaces());
   182   int num_interfaces = interfaces->length();
   183   for (int index = 0; index < num_interfaces; index++) {
   184     HandleMark hm(THREAD);
   185     instanceKlassHandle ih(THREAD, klassOop(interfaces->obj_at(index)));
   186     link_class_impl(ih, throw_verifyerror, CHECK_false);
   187   }
   189   // in case the class is linked in the process of linking its superclasses
   190   if (this_oop->is_linked()) {
   191     return true;
   192   }
   194   // trace only the link time for this klass that includes
   195   // the verification time
   196   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
   197                              ClassLoader::perf_class_link_selftime(),
   198                              ClassLoader::perf_classes_linked(),
   199                              jt->get_thread_stat()->perf_recursion_counts_addr(),
   200                              jt->get_thread_stat()->perf_timers_addr(),
   201                              PerfClassTraceTime::CLASS_LINK);
   203   // verification & rewriting
   204   {
   205     ObjectLocker ol(this_oop, THREAD);
   206     // rewritten will have been set if loader constraint error found
   207     // on an earlier link attempt
   208     // don't verify or rewrite if already rewritten
   209     if (!this_oop->is_linked()) {
   210       if (!this_oop->is_rewritten()) {
   211         {
   212           // Timer includes any side effects of class verification (resolution,
   213           // etc), but not recursive entry into verify_code().
   214           PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
   215                                    ClassLoader::perf_class_verify_selftime(),
   216                                    ClassLoader::perf_classes_verified(),
   217                                    jt->get_thread_stat()->perf_recursion_counts_addr(),
   218                                    jt->get_thread_stat()->perf_timers_addr(),
   219                                    PerfClassTraceTime::CLASS_VERIFY);
   220           bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
   221           if (!verify_ok) {
   222             return false;
   223           }
   224         }
   226         // Just in case a side-effect of verify linked this class already
   227         // (which can sometimes happen since the verifier loads classes
   228         // using custom class loaders, which are free to initialize things)
   229         if (this_oop->is_linked()) {
   230           return true;
   231         }
   233         // also sets rewritten
   234         this_oop->rewrite_class(CHECK_false);
   235       }
   237       // Initialize the vtable and interface table after
   238       // methods have been rewritten since rewrite may
   239       // fabricate new methodOops.
   240       // also does loader constraint checking
   241       if (!this_oop()->is_shared()) {
   242         ResourceMark rm(THREAD);
   243         this_oop->vtable()->initialize_vtable(true, CHECK_false);
   244         this_oop->itable()->initialize_itable(true, CHECK_false);
   245       }
   246 #ifdef ASSERT
   247       else {
   248         ResourceMark rm(THREAD);
   249         this_oop->vtable()->verify(tty, true);
   250         // In case itable verification is ever added.
   251         // this_oop->itable()->verify(tty, true);
   252       }
   253 #endif
   254       this_oop->set_init_state(linked);
   255       if (JvmtiExport::should_post_class_prepare()) {
   256         Thread *thread = THREAD;
   257         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
   258         JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
   259       }
   260     }
   261   }
   262   return true;
   263 }
   266 // Rewrite the byte codes of all of the methods of a class.
   267 // Three cases:
   268 //    During the link of a newly loaded class.
   269 //    During the preloading of classes to be written to the shared spaces.
   270 //      - Rewrite the methods and update the method entry points.
   271 //
   272 //    During the link of a class in the shared spaces.
   273 //      - The methods were already rewritten, update the metho entry points.
   274 //
   275 // The rewriter must be called exactly once. Rewriting must happen after
   276 // verification but before the first method of the class is executed.
   278 void instanceKlass::rewrite_class(TRAPS) {
   279   assert(is_loaded(), "must be loaded");
   280   instanceKlassHandle this_oop(THREAD, this->as_klassOop());
   281   if (this_oop->is_rewritten()) {
   282     assert(this_oop()->is_shared(), "rewriting an unshared class?");
   283     return;
   284   }
   285   Rewriter::rewrite(this_oop, CHECK); // No exception can happen here
   286   this_oop->set_rewritten();
   287 }
   290 void instanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
   291   // Make sure klass is linked (verified) before initialization
   292   // A class could already be verified, since it has been reflected upon.
   293   this_oop->link_class(CHECK);
   295   // refer to the JVM book page 47 for description of steps
   296   // Step 1
   297   { ObjectLocker ol(this_oop, THREAD);
   299     Thread *self = THREAD; // it's passed the current thread
   301     // Step 2
   302     // If we were to use wait() instead of waitInterruptibly() then
   303     // we might end up throwing IE from link/symbol resolution sites
   304     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
   305     while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
   306       ol.waitUninterruptibly(CHECK);
   307     }
   309     // Step 3
   310     if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self))
   311       return;
   313     // Step 4
   314     if (this_oop->is_initialized())
   315       return;
   317     // Step 5
   318     if (this_oop->is_in_error_state()) {
   319       ResourceMark rm(THREAD);
   320       const char* desc = "Could not initialize class ";
   321       const char* className = this_oop->external_name();
   322       size_t msglen = strlen(desc) + strlen(className) + 1;
   323       char* message = NEW_C_HEAP_ARRAY(char, msglen);
   324       if (NULL == message) {
   325         // Out of memory: can't create detailed error message
   326         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
   327       } else {
   328         jio_snprintf(message, msglen, "%s%s", desc, className);
   329         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
   330       }
   331     }
   333     // Step 6
   334     this_oop->set_init_state(being_initialized);
   335     this_oop->set_init_thread(self);
   336   }
   338   // Step 7
   339   klassOop super_klass = this_oop->super();
   340   if (super_klass != NULL && !this_oop->is_interface() && Klass::cast(super_klass)->should_be_initialized()) {
   341     Klass::cast(super_klass)->initialize(THREAD);
   343     if (HAS_PENDING_EXCEPTION) {
   344       Handle e(THREAD, PENDING_EXCEPTION);
   345       CLEAR_PENDING_EXCEPTION;
   346       {
   347         EXCEPTION_MARK;
   348         this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
   349         CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, superclass initialization error is thrown below
   350       }
   351       THROW_OOP(e());
   352     }
   353   }
   355   // Step 8
   356   {
   357     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
   358     JavaThread* jt = (JavaThread*)THREAD;
   359     // Timer includes any side effects of class initialization (resolution,
   360     // etc), but not recursive entry into call_class_initializer().
   361     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
   362                              ClassLoader::perf_class_init_selftime(),
   363                              ClassLoader::perf_classes_inited(),
   364                              jt->get_thread_stat()->perf_recursion_counts_addr(),
   365                              jt->get_thread_stat()->perf_timers_addr(),
   366                              PerfClassTraceTime::CLASS_CLINIT);
   367     this_oop->call_class_initializer(THREAD);
   368   }
   370   // Step 9
   371   if (!HAS_PENDING_EXCEPTION) {
   372     this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
   373     { ResourceMark rm(THREAD);
   374       debug_only(this_oop->vtable()->verify(tty, true);)
   375     }
   376   }
   377   else {
   378     // Step 10 and 11
   379     Handle e(THREAD, PENDING_EXCEPTION);
   380     CLEAR_PENDING_EXCEPTION;
   381     {
   382       EXCEPTION_MARK;
   383       this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
   384       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
   385     }
   386     if (e->is_a(SystemDictionary::error_klass())) {
   387       THROW_OOP(e());
   388     } else {
   389       JavaCallArguments args(e);
   390       THROW_ARG(vmSymbolHandles::java_lang_ExceptionInInitializerError(),
   391                 vmSymbolHandles::throwable_void_signature(),
   392                 &args);
   393     }
   394   }
   395 }
   398 // Note: implementation moved to static method to expose the this pointer.
   399 void instanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
   400   instanceKlassHandle kh(THREAD, this->as_klassOop());
   401   set_initialization_state_and_notify_impl(kh, state, CHECK);
   402 }
   404 void instanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
   405   ObjectLocker ol(this_oop, THREAD);
   406   this_oop->set_init_state(state);
   407   ol.notify_all(CHECK);
   408 }
   410 void instanceKlass::add_implementor(klassOop k) {
   411   assert(Compile_lock->owned_by_self(), "");
   412   // Filter out my subinterfaces.
   413   // (Note: Interfaces are never on the subklass list.)
   414   if (instanceKlass::cast(k)->is_interface()) return;
   416   // Filter out subclasses whose supers already implement me.
   417   // (Note: CHA must walk subclasses of direct implementors
   418   // in order to locate indirect implementors.)
   419   klassOop sk = instanceKlass::cast(k)->super();
   420   if (sk != NULL && instanceKlass::cast(sk)->implements_interface(as_klassOop()))
   421     // We only need to check one immediate superclass, since the
   422     // implements_interface query looks at transitive_interfaces.
   423     // Any supers of the super have the same (or fewer) transitive_interfaces.
   424     return;
   426   // Update number of implementors
   427   int i = _nof_implementors++;
   429   // Record this implementor, if there are not too many already
   430   if (i < implementors_limit) {
   431     assert(_implementors[i] == NULL, "should be exactly one implementor");
   432     oop_store_without_check((oop*)&_implementors[i], k);
   433   } else if (i == implementors_limit) {
   434     // clear out the list on first overflow
   435     for (int i2 = 0; i2 < implementors_limit; i2++)
   436       oop_store_without_check((oop*)&_implementors[i2], NULL);
   437   }
   439   // The implementor also implements the transitive_interfaces
   440   for (int index = 0; index < local_interfaces()->length(); index++) {
   441     instanceKlass::cast(klassOop(local_interfaces()->obj_at(index)))->add_implementor(k);
   442   }
   443 }
   445 void instanceKlass::init_implementor() {
   446   for (int i = 0; i < implementors_limit; i++)
   447     oop_store_without_check((oop*)&_implementors[i], NULL);
   448   _nof_implementors = 0;
   449 }
   452 void instanceKlass::process_interfaces(Thread *thread) {
   453   // link this class into the implementors list of every interface it implements
   454   KlassHandle this_as_oop (thread, this->as_klassOop());
   455   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
   456     assert(local_interfaces()->obj_at(i)->is_klass(), "must be a klass");
   457     instanceKlass* interf = instanceKlass::cast(klassOop(local_interfaces()->obj_at(i)));
   458     assert(interf->is_interface(), "expected interface");
   459     interf->add_implementor(this_as_oop());
   460   }
   461 }
   463 bool instanceKlass::can_be_primary_super_slow() const {
   464   if (is_interface())
   465     return false;
   466   else
   467     return Klass::can_be_primary_super_slow();
   468 }
   470 objArrayOop instanceKlass::compute_secondary_supers(int num_extra_slots, TRAPS) {
   471   // The secondaries are the implemented interfaces.
   472   instanceKlass* ik = instanceKlass::cast(as_klassOop());
   473   objArrayHandle interfaces (THREAD, ik->transitive_interfaces());
   474   int num_secondaries = num_extra_slots + interfaces->length();
   475   if (num_secondaries == 0) {
   476     return Universe::the_empty_system_obj_array();
   477   } else if (num_extra_slots == 0) {
   478     return interfaces();
   479   } else {
   480     // a mix of both
   481     objArrayOop secondaries = oopFactory::new_system_objArray(num_secondaries, CHECK_NULL);
   482     for (int i = 0; i < interfaces->length(); i++) {
   483       secondaries->obj_at_put(num_extra_slots+i, interfaces->obj_at(i));
   484     }
   485     return secondaries;
   486   }
   487 }
   489 bool instanceKlass::compute_is_subtype_of(klassOop k) {
   490   if (Klass::cast(k)->is_interface()) {
   491     return implements_interface(k);
   492   } else {
   493     return Klass::compute_is_subtype_of(k);
   494   }
   495 }
   497 bool instanceKlass::implements_interface(klassOop k) const {
   498   if (as_klassOop() == k) return true;
   499   assert(Klass::cast(k)->is_interface(), "should be an interface class");
   500   for (int i = 0; i < transitive_interfaces()->length(); i++) {
   501     if (transitive_interfaces()->obj_at(i) == k) {
   502       return true;
   503     }
   504   }
   505   return false;
   506 }
   508 objArrayOop instanceKlass::allocate_objArray(int n, int length, TRAPS) {
   509   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
   510   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
   511     report_java_out_of_memory("Requested array size exceeds VM limit");
   512     THROW_OOP_0(Universe::out_of_memory_error_array_size());
   513   }
   514   int size = objArrayOopDesc::object_size(length);
   515   klassOop ak = array_klass(n, CHECK_NULL);
   516   KlassHandle h_ak (THREAD, ak);
   517   objArrayOop o =
   518     (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
   519   return o;
   520 }
   522 instanceOop instanceKlass::register_finalizer(instanceOop i, TRAPS) {
   523   if (TraceFinalizerRegistration) {
   524     tty->print("Registered ");
   525     i->print_value_on(tty);
   526     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
   527   }
   528   instanceHandle h_i(THREAD, i);
   529   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
   530   JavaValue result(T_VOID);
   531   JavaCallArguments args(h_i);
   532   methodHandle mh (THREAD, Universe::finalizer_register_method());
   533   JavaCalls::call(&result, mh, &args, CHECK_NULL);
   534   return h_i();
   535 }
   537 instanceOop instanceKlass::allocate_instance(TRAPS) {
   538   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
   539   int size = size_helper();  // Query before forming handle.
   541   KlassHandle h_k(THREAD, as_klassOop());
   543   instanceOop i;
   545   i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
   546   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
   547     i = register_finalizer(i, CHECK_NULL);
   548   }
   549   return i;
   550 }
   552 instanceOop instanceKlass::allocate_permanent_instance(TRAPS) {
   553   // Finalizer registration occurs in the Object.<init> constructor
   554   // and constructors normally aren't run when allocating perm
   555   // instances so simply disallow finalizable perm objects.  This can
   556   // be relaxed if a need for it is found.
   557   assert(!has_finalizer(), "perm objects not allowed to have finalizers");
   558   int size = size_helper();  // Query before forming handle.
   559   KlassHandle h_k(THREAD, as_klassOop());
   560   instanceOop i = (instanceOop)
   561     CollectedHeap::permanent_obj_allocate(h_k, size, CHECK_NULL);
   562   return i;
   563 }
   565 void instanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
   566   if (is_interface() || is_abstract()) {
   567     ResourceMark rm(THREAD);
   568     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
   569               : vmSymbols::java_lang_InstantiationException(), external_name());
   570   }
   571   if (as_klassOop() == SystemDictionary::class_klass()) {
   572     ResourceMark rm(THREAD);
   573     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
   574               : vmSymbols::java_lang_IllegalAccessException(), external_name());
   575   }
   576 }
   578 klassOop instanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
   579   instanceKlassHandle this_oop(THREAD, as_klassOop());
   580   return array_klass_impl(this_oop, or_null, n, THREAD);
   581 }
   583 klassOop instanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
   584   if (this_oop->array_klasses() == NULL) {
   585     if (or_null) return NULL;
   587     ResourceMark rm;
   588     JavaThread *jt = (JavaThread *)THREAD;
   589     {
   590       // Atomic creation of array_klasses
   591       MutexLocker mc(Compile_lock, THREAD);   // for vtables
   592       MutexLocker ma(MultiArray_lock, THREAD);
   594       // Check if update has already taken place
   595       if (this_oop->array_klasses() == NULL) {
   596         objArrayKlassKlass* oakk =
   597           (objArrayKlassKlass*)Universe::objArrayKlassKlassObj()->klass_part();
   599         klassOop  k = oakk->allocate_objArray_klass(1, this_oop, CHECK_NULL);
   600         this_oop->set_array_klasses(k);
   601       }
   602     }
   603   }
   604   // _this will always be set at this point
   605   objArrayKlass* oak = (objArrayKlass*)this_oop->array_klasses()->klass_part();
   606   if (or_null) {
   607     return oak->array_klass_or_null(n);
   608   }
   609   return oak->array_klass(n, CHECK_NULL);
   610 }
   612 klassOop instanceKlass::array_klass_impl(bool or_null, TRAPS) {
   613   return array_klass_impl(or_null, 1, THREAD);
   614 }
   616 void instanceKlass::call_class_initializer(TRAPS) {
   617   instanceKlassHandle ik (THREAD, as_klassOop());
   618   call_class_initializer_impl(ik, THREAD);
   619 }
   621 static int call_class_initializer_impl_counter = 0;   // for debugging
   623 methodOop instanceKlass::class_initializer() {
   624   return find_method(vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
   625 }
   627 void instanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
   628   methodHandle h_method(THREAD, this_oop->class_initializer());
   629   assert(!this_oop->is_initialized(), "we cannot initialize twice");
   630   if (TraceClassInitialization) {
   631     tty->print("%d Initializing ", call_class_initializer_impl_counter++);
   632     this_oop->name()->print_value();
   633     tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
   634   }
   635   if (h_method() != NULL) {
   636     JavaCallArguments args; // No arguments
   637     JavaValue result(T_VOID);
   638     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
   639   }
   640 }
   643 void instanceKlass::mask_for(methodHandle method, int bci,
   644   InterpreterOopMap* entry_for) {
   645   // Dirty read, then double-check under a lock.
   646   if (_oop_map_cache == NULL) {
   647     // Otherwise, allocate a new one.
   648     MutexLocker x(OopMapCacheAlloc_lock);
   649     // First time use. Allocate a cache in C heap
   650     if (_oop_map_cache == NULL) {
   651       _oop_map_cache = new OopMapCache();
   652     }
   653   }
   654   // _oop_map_cache is constant after init; lookup below does is own locking.
   655   _oop_map_cache->lookup(method, bci, entry_for);
   656 }
   659 bool instanceKlass::find_local_field(symbolOop name, symbolOop sig, fieldDescriptor* fd) const {
   660   const int n = fields()->length();
   661   for (int i = 0; i < n; i += next_offset ) {
   662     int name_index = fields()->ushort_at(i + name_index_offset);
   663     int sig_index  = fields()->ushort_at(i + signature_index_offset);
   664     symbolOop f_name = constants()->symbol_at(name_index);
   665     symbolOop f_sig  = constants()->symbol_at(sig_index);
   666     if (f_name == name && f_sig == sig) {
   667       fd->initialize(as_klassOop(), i);
   668       return true;
   669     }
   670   }
   671   return false;
   672 }
   675 void instanceKlass::field_names_and_sigs_iterate(OopClosure* closure) {
   676   const int n = fields()->length();
   677   for (int i = 0; i < n; i += next_offset ) {
   678     int name_index = fields()->ushort_at(i + name_index_offset);
   679     symbolOop name = constants()->symbol_at(name_index);
   680     closure->do_oop((oop*)&name);
   682     int sig_index  = fields()->ushort_at(i + signature_index_offset);
   683     symbolOop sig = constants()->symbol_at(sig_index);
   684     closure->do_oop((oop*)&sig);
   685   }
   686 }
   689 klassOop instanceKlass::find_interface_field(symbolOop name, symbolOop sig, fieldDescriptor* fd) const {
   690   const int n = local_interfaces()->length();
   691   for (int i = 0; i < n; i++) {
   692     klassOop intf1 = klassOop(local_interfaces()->obj_at(i));
   693     assert(Klass::cast(intf1)->is_interface(), "just checking type");
   694     // search for field in current interface
   695     if (instanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
   696       assert(fd->is_static(), "interface field must be static");
   697       return intf1;
   698     }
   699     // search for field in direct superinterfaces
   700     klassOop intf2 = instanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
   701     if (intf2 != NULL) return intf2;
   702   }
   703   // otherwise field lookup fails
   704   return NULL;
   705 }
   708 klassOop instanceKlass::find_field(symbolOop name, symbolOop sig, fieldDescriptor* fd) const {
   709   // search order according to newest JVM spec (5.4.3.2, p.167).
   710   // 1) search for field in current klass
   711   if (find_local_field(name, sig, fd)) {
   712     return as_klassOop();
   713   }
   714   // 2) search for field recursively in direct superinterfaces
   715   { klassOop intf = find_interface_field(name, sig, fd);
   716     if (intf != NULL) return intf;
   717   }
   718   // 3) apply field lookup recursively if superclass exists
   719   { klassOop supr = super();
   720     if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, fd);
   721   }
   722   // 4) otherwise field lookup fails
   723   return NULL;
   724 }
   727 klassOop instanceKlass::find_field(symbolOop name, symbolOop sig, bool is_static, fieldDescriptor* fd) const {
   728   // search order according to newest JVM spec (5.4.3.2, p.167).
   729   // 1) search for field in current klass
   730   if (find_local_field(name, sig, fd)) {
   731     if (fd->is_static() == is_static) return as_klassOop();
   732   }
   733   // 2) search for field recursively in direct superinterfaces
   734   if (is_static) {
   735     klassOop intf = find_interface_field(name, sig, fd);
   736     if (intf != NULL) return intf;
   737   }
   738   // 3) apply field lookup recursively if superclass exists
   739   { klassOop supr = super();
   740     if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
   741   }
   742   // 4) otherwise field lookup fails
   743   return NULL;
   744 }
   747 bool instanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
   748   int length = fields()->length();
   749   for (int i = 0; i < length; i += next_offset) {
   750     if (offset_from_fields( i ) == offset) {
   751       fd->initialize(as_klassOop(), i);
   752       if (fd->is_static() == is_static) return true;
   753     }
   754   }
   755   return false;
   756 }
   759 bool instanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
   760   klassOop klass = as_klassOop();
   761   while (klass != NULL) {
   762     if (instanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
   763       return true;
   764     }
   765     klass = Klass::cast(klass)->super();
   766   }
   767   return false;
   768 }
   771 void instanceKlass::methods_do(void f(methodOop method)) {
   772   int len = methods()->length();
   773   for (int index = 0; index < len; index++) {
   774     methodOop m = methodOop(methods()->obj_at(index));
   775     assert(m->is_method(), "must be method");
   776     f(m);
   777   }
   778 }
   780 void instanceKlass::do_local_static_fields(FieldClosure* cl) {
   781   fieldDescriptor fd;
   782   int length = fields()->length();
   783   for (int i = 0; i < length; i += next_offset) {
   784     fd.initialize(as_klassOop(), i);
   785     if (fd.is_static()) cl->do_field(&fd);
   786   }
   787 }
   790 void instanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
   791   instanceKlassHandle h_this(THREAD, as_klassOop());
   792   do_local_static_fields_impl(h_this, f, CHECK);
   793 }
   796 void instanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
   797   fieldDescriptor fd;
   798   int length = this_oop->fields()->length();
   799   for (int i = 0; i < length; i += next_offset) {
   800     fd.initialize(this_oop(), i);
   801     if (fd.is_static()) { f(&fd, CHECK); } // Do NOT remove {}! (CHECK macro expands into several statements)
   802   }
   803 }
   806 static int compare_fields_by_offset(int* a, int* b) {
   807   return a[0] - b[0];
   808 }
   810 void instanceKlass::do_nonstatic_fields(FieldClosure* cl) {
   811   instanceKlass* super = superklass();
   812   if (super != NULL) {
   813     super->do_nonstatic_fields(cl);
   814   }
   815   fieldDescriptor fd;
   816   int length = fields()->length();
   817   // In DebugInfo nonstatic fields are sorted by offset.
   818   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1));
   819   int j = 0;
   820   for (int i = 0; i < length; i += next_offset) {
   821     fd.initialize(as_klassOop(), i);
   822     if (!fd.is_static()) {
   823       fields_sorted[j + 0] = fd.offset();
   824       fields_sorted[j + 1] = i;
   825       j += 2;
   826     }
   827   }
   828   if (j > 0) {
   829     length = j;
   830     // _sort_Fn is defined in growableArray.hpp.
   831     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
   832     for (int i = 0; i < length; i += 2) {
   833       fd.initialize(as_klassOop(), fields_sorted[i + 1]);
   834       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
   835       cl->do_field(&fd);
   836     }
   837   }
   838   FREE_C_HEAP_ARRAY(int, fields_sorted);
   839 }
   842 void instanceKlass::array_klasses_do(void f(klassOop k)) {
   843   if (array_klasses() != NULL)
   844     arrayKlass::cast(array_klasses())->array_klasses_do(f);
   845 }
   848 void instanceKlass::with_array_klasses_do(void f(klassOop k)) {
   849   f(as_klassOop());
   850   array_klasses_do(f);
   851 }
   853 #ifdef ASSERT
   854 static int linear_search(objArrayOop methods, symbolOop name, symbolOop signature) {
   855   int len = methods->length();
   856   for (int index = 0; index < len; index++) {
   857     methodOop m = (methodOop)(methods->obj_at(index));
   858     assert(m->is_method(), "must be method");
   859     if (m->signature() == signature && m->name() == name) {
   860        return index;
   861     }
   862   }
   863   return -1;
   864 }
   865 #endif
   867 methodOop instanceKlass::find_method(symbolOop name, symbolOop signature) const {
   868   return instanceKlass::find_method(methods(), name, signature);
   869 }
   871 methodOop instanceKlass::find_method(objArrayOop methods, symbolOop name, symbolOop signature) {
   872   int len = methods->length();
   873   // methods are sorted, so do binary search
   874   int l = 0;
   875   int h = len - 1;
   876   while (l <= h) {
   877     int mid = (l + h) >> 1;
   878     methodOop m = (methodOop)methods->obj_at(mid);
   879     assert(m->is_method(), "must be method");
   880     int res = m->name()->fast_compare(name);
   881     if (res == 0) {
   882       // found matching name; do linear search to find matching signature
   883       // first, quick check for common case
   884       if (m->signature() == signature) return m;
   885       // search downwards through overloaded methods
   886       int i;
   887       for (i = mid - 1; i >= l; i--) {
   888         methodOop m = (methodOop)methods->obj_at(i);
   889         assert(m->is_method(), "must be method");
   890         if (m->name() != name) break;
   891         if (m->signature() == signature) return m;
   892       }
   893       // search upwards
   894       for (i = mid + 1; i <= h; i++) {
   895         methodOop m = (methodOop)methods->obj_at(i);
   896         assert(m->is_method(), "must be method");
   897         if (m->name() != name) break;
   898         if (m->signature() == signature) return m;
   899       }
   900       // not found
   901 #ifdef ASSERT
   902       int index = linear_search(methods, name, signature);
   903       if (index != -1) fatal1("binary search bug: should have found entry %d", index);
   904 #endif
   905       return NULL;
   906     } else if (res < 0) {
   907       l = mid + 1;
   908     } else {
   909       h = mid - 1;
   910     }
   911   }
   912 #ifdef ASSERT
   913   int index = linear_search(methods, name, signature);
   914   if (index != -1) fatal1("binary search bug: should have found entry %d", index);
   915 #endif
   916   return NULL;
   917 }
   919 methodOop instanceKlass::uncached_lookup_method(symbolOop name, symbolOop signature) const {
   920   klassOop klass = as_klassOop();
   921   while (klass != NULL) {
   922     methodOop method = instanceKlass::cast(klass)->find_method(name, signature);
   923     if (method != NULL) return method;
   924     klass = instanceKlass::cast(klass)->super();
   925   }
   926   return NULL;
   927 }
   929 // lookup a method in all the interfaces that this class implements
   930 methodOop instanceKlass::lookup_method_in_all_interfaces(symbolOop name,
   931                                                          symbolOop signature) const {
   932   objArrayOop all_ifs = instanceKlass::cast(as_klassOop())->transitive_interfaces();
   933   int num_ifs = all_ifs->length();
   934   instanceKlass *ik = NULL;
   935   for (int i = 0; i < num_ifs; i++) {
   936     ik = instanceKlass::cast(klassOop(all_ifs->obj_at(i)));
   937     methodOop m = ik->lookup_method(name, signature);
   938     if (m != NULL) {
   939       return m;
   940     }
   941   }
   942   return NULL;
   943 }
   945 /* jni_id_for_impl for jfieldIds only */
   946 JNIid* instanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
   947   MutexLocker ml(JfieldIdCreation_lock);
   948   // Retry lookup after we got the lock
   949   JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
   950   if (probe == NULL) {
   951     // Slow case, allocate new static field identifier
   952     probe = new JNIid(this_oop->as_klassOop(), offset, this_oop->jni_ids());
   953     this_oop->set_jni_ids(probe);
   954   }
   955   return probe;
   956 }
   959 /* jni_id_for for jfieldIds only */
   960 JNIid* instanceKlass::jni_id_for(int offset) {
   961   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
   962   if (probe == NULL) {
   963     probe = jni_id_for_impl(this->as_klassOop(), offset);
   964   }
   965   return probe;
   966 }
   969 // Lookup or create a jmethodID.
   970 // This code can be called by the VM thread.  For this reason it is critical that
   971 // there are no blocking operations (safepoints) while the lock is held -- or a
   972 // deadlock can occur.
   973 jmethodID instanceKlass::jmethod_id_for_impl(instanceKlassHandle ik_h, methodHandle method_h) {
   974   size_t idnum = (size_t)method_h->method_idnum();
   975   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
   976   size_t length = 0;
   977   jmethodID id = NULL;
   978   // array length stored in first element, other elements offset by one
   979   if (jmeths == NULL ||                         // If there is no jmethodID array,
   980       (length = (size_t)jmeths[0]) <= idnum ||  // or if it is too short,
   981       (id = jmeths[idnum+1]) == NULL) {         // or if this jmethodID isn't allocated
   983     // Do all the safepointing things (allocations) before grabbing the lock.
   984     // These allocations will have to be freed if they are unused.
   986     // Allocate a new array of methods.
   987     jmethodID* new_jmeths = NULL;
   988     if (length <= idnum) {
   989       // A new array will be needed (unless some other thread beats us to it)
   990       size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
   991       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1);
   992       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
   993       new_jmeths[0] =(jmethodID)size;  // array size held in the first element
   994     }
   996     // Allocate a new method ID.
   997     jmethodID new_id = NULL;
   998     if (method_h->is_old() && !method_h->is_obsolete()) {
   999       // The method passed in is old (but not obsolete), we need to use the current version
  1000       methodOop current_method = ik_h->method_with_idnum((int)idnum);
  1001       assert(current_method != NULL, "old and but not obsolete, so should exist");
  1002       methodHandle current_method_h(current_method == NULL? method_h() : current_method);
  1003       new_id = JNIHandles::make_jmethod_id(current_method_h);
  1004     } else {
  1005       // It is the current version of the method or an obsolete method,
  1006       // use the version passed in
  1007       new_id = JNIHandles::make_jmethod_id(method_h);
  1010     if (Threads::number_of_threads() == 0 || SafepointSynchronize::is_at_safepoint()) {
  1011       // No need and unsafe to lock the JmethodIdCreation_lock at safepoint.
  1012       id = get_jmethod_id(ik_h, idnum, new_id, new_jmeths);
  1013     } else {
  1014       MutexLocker ml(JmethodIdCreation_lock);
  1015       id = get_jmethod_id(ik_h, idnum, new_id, new_jmeths);
  1018   return id;
  1022 jmethodID instanceKlass::get_jmethod_id(instanceKlassHandle ik_h, size_t idnum,
  1023                                         jmethodID new_id, jmethodID* new_jmeths) {
  1024   // Retry lookup after we got the lock or ensured we are at safepoint
  1025   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
  1026   jmethodID  id                = NULL;
  1027   jmethodID  to_dealloc_id     = NULL;
  1028   jmethodID* to_dealloc_jmeths = NULL;
  1029   size_t     length;
  1031   if (jmeths == NULL || (length = (size_t)jmeths[0]) <= idnum) {
  1032     if (jmeths != NULL) {
  1033       // We have grown the array: copy the existing entries, and delete the old array
  1034       for (size_t index = 0; index < length; index++) {
  1035         new_jmeths[index+1] = jmeths[index+1];
  1037       to_dealloc_jmeths = jmeths; // using the new jmeths, deallocate the old one
  1039     ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
  1040   } else {
  1041     id = jmeths[idnum+1];
  1042     to_dealloc_jmeths = new_jmeths; // using the old jmeths, deallocate the new one
  1044   if (id == NULL) {
  1045     id = new_id;
  1046     jmeths[idnum+1] = id;  // install the new method ID
  1047   } else {
  1048     to_dealloc_id = new_id; // the new id wasn't used, mark it for deallocation
  1051   // Free up unneeded or no longer needed resources
  1052   FreeHeap(to_dealloc_jmeths);
  1053   if (to_dealloc_id != NULL) {
  1054     JNIHandles::destroy_jmethod_id(to_dealloc_id);
  1056   return id;
  1060 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
  1061 jmethodID instanceKlass::jmethod_id_or_null(methodOop method) {
  1062   size_t idnum = (size_t)method->method_idnum();
  1063   jmethodID* jmeths = methods_jmethod_ids_acquire();
  1064   size_t length;                                // length assigned as debugging crumb
  1065   jmethodID id = NULL;
  1066   if (jmeths != NULL &&                         // If there is a jmethodID array,
  1067       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
  1068     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
  1070   return id;
  1074 // Cache an itable index
  1075 void instanceKlass::set_cached_itable_index(size_t idnum, int index) {
  1076   int* indices = methods_cached_itable_indices_acquire();
  1077   if (indices == NULL ||                         // If there is no index array,
  1078       ((size_t)indices[0]) <= idnum) {           // or if it is too short
  1079     // Lock before we allocate the array so we don't leak
  1080     MutexLocker ml(JNICachedItableIndex_lock);
  1081     // Retry lookup after we got the lock
  1082     indices = methods_cached_itable_indices_acquire();
  1083     size_t length = 0;
  1084     // array length stored in first element, other elements offset by one
  1085     if (indices == NULL || (length = (size_t)indices[0]) <= idnum) {
  1086       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
  1087       int* new_indices = NEW_C_HEAP_ARRAY(int, size+1);
  1088       new_indices[0] =(int)size;  // array size held in the first element
  1089       // Copy the existing entries, if any
  1090       size_t i;
  1091       for (i = 0; i < length; i++) {
  1092         new_indices[i+1] = indices[i+1];
  1094       // Set all the rest to -1
  1095       for (i = length; i < size; i++) {
  1096         new_indices[i+1] = -1;
  1098       if (indices != NULL) {
  1099         FreeHeap(indices);  // delete any old indices
  1101       release_set_methods_cached_itable_indices(indices = new_indices);
  1103   } else {
  1104     CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
  1106   // This is a cache, if there is a race to set it, it doesn't matter
  1107   indices[idnum+1] = index;
  1111 // Retrieve a cached itable index
  1112 int instanceKlass::cached_itable_index(size_t idnum) {
  1113   int* indices = methods_cached_itable_indices_acquire();
  1114   if (indices != NULL && ((size_t)indices[0]) > idnum) {
  1115      // indices exist and are long enough, retrieve possible cached
  1116     return indices[idnum+1];
  1118   return -1;
  1122 //
  1123 // nmethodBucket is used to record dependent nmethods for
  1124 // deoptimization.  nmethod dependencies are actually <klass, method>
  1125 // pairs but we really only care about the klass part for purposes of
  1126 // finding nmethods which might need to be deoptimized.  Instead of
  1127 // recording the method, a count of how many times a particular nmethod
  1128 // was recorded is kept.  This ensures that any recording errors are
  1129 // noticed since an nmethod should be removed as many times are it's
  1130 // added.
  1131 //
  1132 class nmethodBucket {
  1133  private:
  1134   nmethod*       _nmethod;
  1135   int            _count;
  1136   nmethodBucket* _next;
  1138  public:
  1139   nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
  1140     _nmethod = nmethod;
  1141     _next = next;
  1142     _count = 1;
  1144   int count()                             { return _count; }
  1145   int increment()                         { _count += 1; return _count; }
  1146   int decrement()                         { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
  1147   nmethodBucket* next()                   { return _next; }
  1148   void set_next(nmethodBucket* b)         { _next = b; }
  1149   nmethod* get_nmethod()                  { return _nmethod; }
  1150 };
  1153 //
  1154 // Walk the list of dependent nmethods searching for nmethods which
  1155 // are dependent on the klassOop that was passed in and mark them for
  1156 // deoptimization.  Returns the number of nmethods found.
  1157 //
  1158 int instanceKlass::mark_dependent_nmethods(DepChange& changes) {
  1159   assert_locked_or_safepoint(CodeCache_lock);
  1160   int found = 0;
  1161   nmethodBucket* b = _dependencies;
  1162   while (b != NULL) {
  1163     nmethod* nm = b->get_nmethod();
  1164     // since dependencies aren't removed until an nmethod becomes a zombie,
  1165     // the dependency list may contain nmethods which aren't alive.
  1166     if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
  1167       if (TraceDependencies) {
  1168         ResourceMark rm;
  1169         tty->print_cr("Marked for deoptimization");
  1170         tty->print_cr("  context = %s", this->external_name());
  1171         changes.print();
  1172         nm->print();
  1173         nm->print_dependencies();
  1175       nm->mark_for_deoptimization();
  1176       found++;
  1178     b = b->next();
  1180   return found;
  1184 //
  1185 // Add an nmethodBucket to the list of dependencies for this nmethod.
  1186 // It's possible that an nmethod has multiple dependencies on this klass
  1187 // so a count is kept for each bucket to guarantee that creation and
  1188 // deletion of dependencies is consistent.
  1189 //
  1190 void instanceKlass::add_dependent_nmethod(nmethod* nm) {
  1191   assert_locked_or_safepoint(CodeCache_lock);
  1192   nmethodBucket* b = _dependencies;
  1193   nmethodBucket* last = NULL;
  1194   while (b != NULL) {
  1195     if (nm == b->get_nmethod()) {
  1196       b->increment();
  1197       return;
  1199     b = b->next();
  1201   _dependencies = new nmethodBucket(nm, _dependencies);
  1205 //
  1206 // Decrement count of the nmethod in the dependency list and remove
  1207 // the bucket competely when the count goes to 0.  This method must
  1208 // find a corresponding bucket otherwise there's a bug in the
  1209 // recording of dependecies.
  1210 //
  1211 void instanceKlass::remove_dependent_nmethod(nmethod* nm) {
  1212   assert_locked_or_safepoint(CodeCache_lock);
  1213   nmethodBucket* b = _dependencies;
  1214   nmethodBucket* last = NULL;
  1215   while (b != NULL) {
  1216     if (nm == b->get_nmethod()) {
  1217       if (b->decrement() == 0) {
  1218         if (last == NULL) {
  1219           _dependencies = b->next();
  1220         } else {
  1221           last->set_next(b->next());
  1223         delete b;
  1225       return;
  1227     last = b;
  1228     b = b->next();
  1230 #ifdef ASSERT
  1231   tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
  1232   nm->print();
  1233 #endif // ASSERT
  1234   ShouldNotReachHere();
  1238 #ifndef PRODUCT
  1239 void instanceKlass::print_dependent_nmethods(bool verbose) {
  1240   nmethodBucket* b = _dependencies;
  1241   int idx = 0;
  1242   while (b != NULL) {
  1243     nmethod* nm = b->get_nmethod();
  1244     tty->print("[%d] count=%d { ", idx++, b->count());
  1245     if (!verbose) {
  1246       nm->print_on(tty, "nmethod");
  1247       tty->print_cr(" } ");
  1248     } else {
  1249       nm->print();
  1250       nm->print_dependencies();
  1251       tty->print_cr("--- } ");
  1253     b = b->next();
  1258 bool instanceKlass::is_dependent_nmethod(nmethod* nm) {
  1259   nmethodBucket* b = _dependencies;
  1260   while (b != NULL) {
  1261     if (nm == b->get_nmethod()) {
  1262       return true;
  1264     b = b->next();
  1266   return false;
  1268 #endif //PRODUCT
  1271 #ifdef ASSERT
  1272 template <class T> void assert_is_in(T *p) {
  1273   T heap_oop = oopDesc::load_heap_oop(p);
  1274   if (!oopDesc::is_null(heap_oop)) {
  1275     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1276     assert(Universe::heap()->is_in(o), "should be in heap");
  1279 template <class T> void assert_is_in_closed_subset(T *p) {
  1280   T heap_oop = oopDesc::load_heap_oop(p);
  1281   if (!oopDesc::is_null(heap_oop)) {
  1282     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1283     assert(Universe::heap()->is_in_closed_subset(o), "should be in closed");
  1286 template <class T> void assert_is_in_reserved(T *p) {
  1287   T heap_oop = oopDesc::load_heap_oop(p);
  1288   if (!oopDesc::is_null(heap_oop)) {
  1289     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
  1290     assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
  1293 template <class T> void assert_nothing(T *p) {}
  1295 #else
  1296 template <class T> void assert_is_in(T *p) {}
  1297 template <class T> void assert_is_in_closed_subset(T *p) {}
  1298 template <class T> void assert_is_in_reserved(T *p) {}
  1299 template <class T> void assert_nothing(T *p) {}
  1300 #endif // ASSERT
  1302 //
  1303 // Macros that iterate over areas of oops which are specialized on type of
  1304 // oop pointer either narrow or wide, depending on UseCompressedOops
  1305 //
  1306 // Parameters are:
  1307 //   T         - type of oop to point to (either oop or narrowOop)
  1308 //   start_p   - starting pointer for region to iterate over
  1309 //   count     - number of oops or narrowOops to iterate over
  1310 //   do_oop    - action to perform on each oop (it's arbitrary C code which
  1311 //               makes it more efficient to put in a macro rather than making
  1312 //               it a template function)
  1313 //   assert_fn - assert function which is template function because performance
  1314 //               doesn't matter when enabled.
  1315 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
  1316   T, start_p, count, do_oop,                \
  1317   assert_fn)                                \
  1318 {                                           \
  1319   T* p         = (T*)(start_p);             \
  1320   T* const end = p + (count);               \
  1321   while (p < end) {                         \
  1322     (assert_fn)(p);                         \
  1323     do_oop;                                 \
  1324     ++p;                                    \
  1325   }                                         \
  1328 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
  1329   T, start_p, count, do_oop,                \
  1330   assert_fn)                                \
  1331 {                                           \
  1332   T* const start = (T*)(start_p);           \
  1333   T*       p     = start + (count);         \
  1334   while (start < p) {                       \
  1335     --p;                                    \
  1336     (assert_fn)(p);                         \
  1337     do_oop;                                 \
  1338   }                                         \
  1341 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
  1342   T, start_p, count, low, high,             \
  1343   do_oop, assert_fn)                        \
  1344 {                                           \
  1345   T* const l = (T*)(low);                   \
  1346   T* const h = (T*)(high);                  \
  1347   assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
  1348          mask_bits((intptr_t)h, sizeof(T)-1) == 0,   \
  1349          "bounded region must be properly aligned"); \
  1350   T* p       = (T*)(start_p);               \
  1351   T* end     = p + (count);                 \
  1352   if (p < l) p = l;                         \
  1353   if (end > h) end = h;                     \
  1354   while (p < end) {                         \
  1355     (assert_fn)(p);                         \
  1356     do_oop;                                 \
  1357     ++p;                                    \
  1358   }                                         \
  1362 // The following macros call specialized macros, passing either oop or
  1363 // narrowOop as the specialization type.  These test the UseCompressedOops
  1364 // flag.
  1365 #define InstanceKlass_OOP_ITERATE(start_p, count,    \
  1366                                   do_oop, assert_fn) \
  1367 {                                                    \
  1368   if (UseCompressedOops) {                           \
  1369     InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop, \
  1370       start_p, count,                                \
  1371       do_oop, assert_fn)                             \
  1372   } else {                                           \
  1373     InstanceKlass_SPECIALIZED_OOP_ITERATE(oop,       \
  1374       start_p, count,                                \
  1375       do_oop, assert_fn)                             \
  1376   }                                                  \
  1379 #define InstanceKlass_BOUNDED_OOP_ITERATE(start_p, count, low, high,    \
  1380                                           do_oop, assert_fn) \
  1381 {                                                            \
  1382   if (UseCompressedOops) {                                   \
  1383     InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop, \
  1384       start_p, count,                                        \
  1385       low, high,                                             \
  1386       do_oop, assert_fn)                                     \
  1387   } else {                                                   \
  1388     InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop,       \
  1389       start_p, count,                                        \
  1390       low, high,                                             \
  1391       do_oop, assert_fn)                                     \
  1392   }                                                          \
  1395 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn)            \
  1396 {                                                                        \
  1397   /* Compute oopmap block range. The common case                         \
  1398      is nonstatic_oop_map_size == 1. */                                  \
  1399   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  1400   OopMapBlock* const end_map = map + nonstatic_oop_map_size();           \
  1401   if (UseCompressedOops) {                                               \
  1402     while (map < end_map) {                                              \
  1403       InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop,                   \
  1404         obj->obj_field_addr<narrowOop>(map->offset()), map->length(),    \
  1405         do_oop, assert_fn)                                               \
  1406       ++map;                                                             \
  1407     }                                                                    \
  1408   } else {                                                               \
  1409     while (map < end_map) {                                              \
  1410       InstanceKlass_SPECIALIZED_OOP_ITERATE(oop,                         \
  1411         obj->obj_field_addr<oop>(map->offset()), map->length(),          \
  1412         do_oop, assert_fn)                                               \
  1413       ++map;                                                             \
  1414     }                                                                    \
  1415   }                                                                      \
  1418 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn)    \
  1419 {                                                                        \
  1420   OopMapBlock* const start_map = start_of_nonstatic_oop_maps();          \
  1421   OopMapBlock* map             = start_map + nonstatic_oop_map_size();   \
  1422   if (UseCompressedOops) {                                               \
  1423     while (start_map < map) {                                            \
  1424       --map;                                                             \
  1425       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop,           \
  1426         obj->obj_field_addr<narrowOop>(map->offset()), map->length(),    \
  1427         do_oop, assert_fn)                                               \
  1428     }                                                                    \
  1429   } else {                                                               \
  1430     while (start_map < map) {                                            \
  1431       --map;                                                             \
  1432       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop,                 \
  1433         obj->obj_field_addr<oop>(map->offset()), map->length(),          \
  1434         do_oop, assert_fn)                                               \
  1435     }                                                                    \
  1436   }                                                                      \
  1439 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop,    \
  1440                                               assert_fn)                 \
  1441 {                                                                        \
  1442   /* Compute oopmap block range. The common case is                      \
  1443      nonstatic_oop_map_size == 1, so we accept the                       \
  1444      usually non-existent extra overhead of examining                    \
  1445      all the maps. */                                                    \
  1446   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
  1447   OopMapBlock* const end_map = map + nonstatic_oop_map_size();           \
  1448   if (UseCompressedOops) {                                               \
  1449     while (map < end_map) {                                              \
  1450       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop,           \
  1451         obj->obj_field_addr<narrowOop>(map->offset()), map->length(),    \
  1452         low, high,                                                       \
  1453         do_oop, assert_fn)                                               \
  1454       ++map;                                                             \
  1455     }                                                                    \
  1456   } else {                                                               \
  1457     while (map < end_map) {                                              \
  1458       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop,                 \
  1459         obj->obj_field_addr<oop>(map->offset()), map->length(),          \
  1460         low, high,                                                       \
  1461         do_oop, assert_fn)                                               \
  1462       ++map;                                                             \
  1463     }                                                                    \
  1464   }                                                                      \
  1467 void instanceKlass::follow_static_fields() {
  1468   InstanceKlass_OOP_ITERATE( \
  1469     start_of_static_fields(), static_oop_field_size(), \
  1470     MarkSweep::mark_and_push(p), \
  1471     assert_is_in_closed_subset)
  1474 #ifndef SERIALGC
  1475 void instanceKlass::follow_static_fields(ParCompactionManager* cm) {
  1476   InstanceKlass_OOP_ITERATE( \
  1477     start_of_static_fields(), static_oop_field_size(), \
  1478     PSParallelCompact::mark_and_push(cm, p), \
  1479     assert_is_in)
  1481 #endif // SERIALGC
  1483 void instanceKlass::adjust_static_fields() {
  1484   InstanceKlass_OOP_ITERATE( \
  1485     start_of_static_fields(), static_oop_field_size(), \
  1486     MarkSweep::adjust_pointer(p), \
  1487     assert_nothing)
  1490 #ifndef SERIALGC
  1491 void instanceKlass::update_static_fields() {
  1492   InstanceKlass_OOP_ITERATE( \
  1493     start_of_static_fields(), static_oop_field_size(), \
  1494     PSParallelCompact::adjust_pointer(p), \
  1495     assert_nothing)
  1498 void instanceKlass::update_static_fields(HeapWord* beg_addr, HeapWord* end_addr) {
  1499   InstanceKlass_BOUNDED_OOP_ITERATE( \
  1500     start_of_static_fields(), static_oop_field_size(), \
  1501     beg_addr, end_addr, \
  1502     PSParallelCompact::adjust_pointer(p), \
  1503     assert_nothing )
  1505 #endif // SERIALGC
  1507 void instanceKlass::oop_follow_contents(oop obj) {
  1508   assert(obj != NULL, "can't follow the content of NULL object");
  1509   obj->follow_header();
  1510   InstanceKlass_OOP_MAP_ITERATE( \
  1511     obj, \
  1512     MarkSweep::mark_and_push(p), \
  1513     assert_is_in_closed_subset)
  1516 #ifndef SERIALGC
  1517 void instanceKlass::oop_follow_contents(ParCompactionManager* cm,
  1518                                         oop obj) {
  1519   assert(obj != NULL, "can't follow the content of NULL object");
  1520   obj->follow_header(cm);
  1521   InstanceKlass_OOP_MAP_ITERATE( \
  1522     obj, \
  1523     PSParallelCompact::mark_and_push(cm, p), \
  1524     assert_is_in)
  1526 #endif // SERIALGC
  1528 // closure's do_header() method dicates whether the given closure should be
  1529 // applied to the klass ptr in the object header.
  1531 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)        \
  1533 int instanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
  1534   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  1535   /* header */                                                          \
  1536   if (closure->do_header()) {                                           \
  1537     obj->oop_iterate_header(closure);                                   \
  1538   }                                                                     \
  1539   InstanceKlass_OOP_MAP_ITERATE(                                        \
  1540     obj,                                                                \
  1541     SpecializationStats::                                               \
  1542       record_do_oop_call##nv_suffix(SpecializationStats::ik);           \
  1543     (closure)->do_oop##nv_suffix(p),                                    \
  1544     assert_is_in_closed_subset)                                         \
  1545   return size_helper();                                                 \
  1548 #ifndef SERIALGC
  1549 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
  1551 int instanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj,                \
  1552                                               OopClosureType* closure) {        \
  1553   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
  1554   /* header */                                                                  \
  1555   if (closure->do_header()) {                                                   \
  1556     obj->oop_iterate_header(closure);                                           \
  1557   }                                                                             \
  1558   /* instance variables */                                                      \
  1559   InstanceKlass_OOP_MAP_REVERSE_ITERATE(                                        \
  1560     obj,                                                                        \
  1561     SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
  1562     (closure)->do_oop##nv_suffix(p),                                            \
  1563     assert_is_in_closed_subset)                                                 \
  1564    return size_helper();                                                        \
  1566 #endif // !SERIALGC
  1568 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
  1570 int instanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj,              \
  1571                                                   OopClosureType* closure, \
  1572                                                   MemRegion mr) {          \
  1573   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
  1574   if (closure->do_header()) {                                            \
  1575     obj->oop_iterate_header(closure, mr);                                \
  1576   }                                                                      \
  1577   InstanceKlass_BOUNDED_OOP_MAP_ITERATE(                                 \
  1578     obj, mr.start(), mr.end(),                                           \
  1579     (closure)->do_oop##nv_suffix(p),                                     \
  1580     assert_is_in_closed_subset)                                          \
  1581   return size_helper();                                                  \
  1584 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
  1585 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
  1586 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
  1587 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
  1588 #ifndef SERIALGC
  1589 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
  1590 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
  1591 #endif // !SERIALGC
  1593 void instanceKlass::iterate_static_fields(OopClosure* closure) {
  1594     InstanceKlass_OOP_ITERATE( \
  1595       start_of_static_fields(), static_oop_field_size(), \
  1596       closure->do_oop(p), \
  1597       assert_is_in_reserved)
  1600 void instanceKlass::iterate_static_fields(OopClosure* closure,
  1601                                           MemRegion mr) {
  1602   InstanceKlass_BOUNDED_OOP_ITERATE( \
  1603     start_of_static_fields(), static_oop_field_size(), \
  1604     mr.start(), mr.end(), \
  1605     (closure)->do_oop_v(p), \
  1606     assert_is_in_closed_subset)
  1609 int instanceKlass::oop_adjust_pointers(oop obj) {
  1610   int size = size_helper();
  1611   InstanceKlass_OOP_MAP_ITERATE( \
  1612     obj, \
  1613     MarkSweep::adjust_pointer(p), \
  1614     assert_is_in)
  1615   obj->adjust_header();
  1616   return size;
  1619 #ifndef SERIALGC
  1620 void instanceKlass::oop_copy_contents(PSPromotionManager* pm, oop obj) {
  1621   assert(!pm->depth_first(), "invariant");
  1622   InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
  1623     obj, \
  1624     if (PSScavenge::should_scavenge(p)) { \
  1625       pm->claim_or_forward_breadth(p); \
  1626     }, \
  1627     assert_nothing )
  1630 void instanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
  1631   assert(pm->depth_first(), "invariant");
  1632   InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
  1633     obj, \
  1634     if (PSScavenge::should_scavenge(p)) { \
  1635       pm->claim_or_forward_depth(p); \
  1636     }, \
  1637     assert_nothing )
  1640 int instanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
  1641   InstanceKlass_OOP_MAP_ITERATE( \
  1642     obj, \
  1643     PSParallelCompact::adjust_pointer(p), \
  1644     assert_nothing)
  1645   return size_helper();
  1648 int instanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj,
  1649                                        HeapWord* beg_addr, HeapWord* end_addr) {
  1650   InstanceKlass_BOUNDED_OOP_MAP_ITERATE( \
  1651     obj, beg_addr, end_addr, \
  1652     PSParallelCompact::adjust_pointer(p), \
  1653     assert_nothing)
  1654   return size_helper();
  1657 void instanceKlass::copy_static_fields(PSPromotionManager* pm) {
  1658   assert(!pm->depth_first(), "invariant");
  1659   InstanceKlass_OOP_ITERATE( \
  1660     start_of_static_fields(), static_oop_field_size(), \
  1661     if (PSScavenge::should_scavenge(p)) { \
  1662       pm->claim_or_forward_breadth(p); \
  1663     }, \
  1664     assert_nothing )
  1667 void instanceKlass::push_static_fields(PSPromotionManager* pm) {
  1668   assert(pm->depth_first(), "invariant");
  1669   InstanceKlass_OOP_ITERATE( \
  1670     start_of_static_fields(), static_oop_field_size(), \
  1671     if (PSScavenge::should_scavenge(p)) { \
  1672       pm->claim_or_forward_depth(p); \
  1673     }, \
  1674     assert_nothing )
  1677 void instanceKlass::copy_static_fields(ParCompactionManager* cm) {
  1678   InstanceKlass_OOP_ITERATE( \
  1679     start_of_static_fields(), static_oop_field_size(), \
  1680     PSParallelCompact::adjust_pointer(p), \
  1681     assert_is_in)
  1683 #endif // SERIALGC
  1685 // This klass is alive but the implementor link is not followed/updated.
  1686 // Subklass and sibling links are handled by Klass::follow_weak_klass_links
  1688 void instanceKlass::follow_weak_klass_links(
  1689   BoolObjectClosure* is_alive, OopClosure* keep_alive) {
  1690   assert(is_alive->do_object_b(as_klassOop()), "this oop should be live");
  1691   if (ClassUnloading) {
  1692     for (int i = 0; i < implementors_limit; i++) {
  1693       klassOop impl = _implementors[i];
  1694       if (impl == NULL)  break;  // no more in the list
  1695       if (!is_alive->do_object_b(impl)) {
  1696         // remove this guy from the list by overwriting him with the tail
  1697         int lasti = --_nof_implementors;
  1698         assert(lasti >= i && lasti < implementors_limit, "just checking");
  1699         _implementors[i] = _implementors[lasti];
  1700         _implementors[lasti] = NULL;
  1701         --i; // rerun the loop at this index
  1704   } else {
  1705     for (int i = 0; i < implementors_limit; i++) {
  1706       keep_alive->do_oop(&adr_implementors()[i]);
  1709   Klass::follow_weak_klass_links(is_alive, keep_alive);
  1712 void instanceKlass::remove_unshareable_info() {
  1713   Klass::remove_unshareable_info();
  1714   init_implementor();
  1717 static void clear_all_breakpoints(methodOop m) {
  1718   m->clear_all_breakpoints();
  1721 void instanceKlass::release_C_heap_structures() {
  1722   // Deallocate oop map cache
  1723   if (_oop_map_cache != NULL) {
  1724     delete _oop_map_cache;
  1725     _oop_map_cache = NULL;
  1728   // Deallocate JNI identifiers for jfieldIDs
  1729   JNIid::deallocate(jni_ids());
  1730   set_jni_ids(NULL);
  1732   jmethodID* jmeths = methods_jmethod_ids_acquire();
  1733   if (jmeths != (jmethodID*)NULL) {
  1734     release_set_methods_jmethod_ids(NULL);
  1735     FreeHeap(jmeths);
  1738   int* indices = methods_cached_itable_indices_acquire();
  1739   if (indices != (int*)NULL) {
  1740     release_set_methods_cached_itable_indices(NULL);
  1741     FreeHeap(indices);
  1744   // release dependencies
  1745   nmethodBucket* b = _dependencies;
  1746   _dependencies = NULL;
  1747   while (b != NULL) {
  1748     nmethodBucket* next = b->next();
  1749     delete b;
  1750     b = next;
  1753   // Deallocate breakpoint records
  1754   if (breakpoints() != 0x0) {
  1755     methods_do(clear_all_breakpoints);
  1756     assert(breakpoints() == 0x0, "should have cleared breakpoints");
  1759   // deallocate information about previous versions
  1760   if (_previous_versions != NULL) {
  1761     for (int i = _previous_versions->length() - 1; i >= 0; i--) {
  1762       PreviousVersionNode * pv_node = _previous_versions->at(i);
  1763       delete pv_node;
  1765     delete _previous_versions;
  1766     _previous_versions = NULL;
  1769   // deallocate the cached class file
  1770   if (_cached_class_file_bytes != NULL) {
  1771     os::free(_cached_class_file_bytes);
  1772     _cached_class_file_bytes = NULL;
  1773     _cached_class_file_len = 0;
  1777 char* instanceKlass::signature_name() const {
  1778   const char* src = (const char*) (name()->as_C_string());
  1779   const int src_length = (int)strlen(src);
  1780   char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
  1781   int src_index = 0;
  1782   int dest_index = 0;
  1783   dest[dest_index++] = 'L';
  1784   while (src_index < src_length) {
  1785     dest[dest_index++] = src[src_index++];
  1787   dest[dest_index++] = ';';
  1788   dest[dest_index] = '\0';
  1789   return dest;
  1792 // different verisons of is_same_class_package
  1793 bool instanceKlass::is_same_class_package(klassOop class2) {
  1794   klassOop class1 = as_klassOop();
  1795   oop classloader1 = instanceKlass::cast(class1)->class_loader();
  1796   symbolOop classname1 = Klass::cast(class1)->name();
  1798   if (Klass::cast(class2)->oop_is_objArray()) {
  1799     class2 = objArrayKlass::cast(class2)->bottom_klass();
  1801   oop classloader2;
  1802   if (Klass::cast(class2)->oop_is_instance()) {
  1803     classloader2 = instanceKlass::cast(class2)->class_loader();
  1804   } else {
  1805     assert(Klass::cast(class2)->oop_is_typeArray(), "should be type array");
  1806     classloader2 = NULL;
  1808   symbolOop classname2 = Klass::cast(class2)->name();
  1810   return instanceKlass::is_same_class_package(classloader1, classname1,
  1811                                               classloader2, classname2);
  1814 bool instanceKlass::is_same_class_package(oop classloader2, symbolOop classname2) {
  1815   klassOop class1 = as_klassOop();
  1816   oop classloader1 = instanceKlass::cast(class1)->class_loader();
  1817   symbolOop classname1 = Klass::cast(class1)->name();
  1819   return instanceKlass::is_same_class_package(classloader1, classname1,
  1820                                               classloader2, classname2);
  1823 // return true if two classes are in the same package, classloader
  1824 // and classname information is enough to determine a class's package
  1825 bool instanceKlass::is_same_class_package(oop class_loader1, symbolOop class_name1,
  1826                                           oop class_loader2, symbolOop class_name2) {
  1827   if (class_loader1 != class_loader2) {
  1828     return false;
  1829   } else if (class_name1 == class_name2) {
  1830     return true;                // skip painful bytewise comparison
  1831   } else {
  1832     ResourceMark rm;
  1834     // The symbolOop's are in UTF8 encoding. Since we only need to check explicitly
  1835     // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
  1836     // Otherwise, we just compare jbyte values between the strings.
  1837     jbyte *name1 = class_name1->base();
  1838     jbyte *name2 = class_name2->base();
  1840     jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
  1841     jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
  1843     if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
  1844       // One of the two doesn't have a package.  Only return true
  1845       // if the other one also doesn't have a package.
  1846       return last_slash1 == last_slash2;
  1847     } else {
  1848       // Skip over '['s
  1849       if (*name1 == '[') {
  1850         do {
  1851           name1++;
  1852         } while (*name1 == '[');
  1853         if (*name1 != 'L') {
  1854           // Something is terribly wrong.  Shouldn't be here.
  1855           return false;
  1858       if (*name2 == '[') {
  1859         do {
  1860           name2++;
  1861         } while (*name2 == '[');
  1862         if (*name2 != 'L') {
  1863           // Something is terribly wrong.  Shouldn't be here.
  1864           return false;
  1868       // Check that package part is identical
  1869       int length1 = last_slash1 - name1;
  1870       int length2 = last_slash2 - name2;
  1872       return UTF8::equal(name1, length1, name2, length2);
  1877 // Returns true iff super_method can be overridden by a method in targetclassname
  1878 // See JSL 3rd edition 8.4.6.1
  1879 // Assumes name-signature match
  1880 // "this" is instanceKlass of super_method which must exist
  1881 // note that the instanceKlass of the method in the targetclassname has not always been created yet
  1882 bool instanceKlass::is_override(methodHandle super_method, Handle targetclassloader, symbolHandle targetclassname, TRAPS) {
  1883    // Private methods can not be overridden
  1884    if (super_method->is_private()) {
  1885      return false;
  1887    // If super method is accessible, then override
  1888    if ((super_method->is_protected()) ||
  1889        (super_method->is_public())) {
  1890      return true;
  1892    // Package-private methods are not inherited outside of package
  1893    assert(super_method->is_package_private(), "must be package private");
  1894    return(is_same_class_package(targetclassloader(), targetclassname()));
  1897 /* defined for now in jvm.cpp, for historical reasons *--
  1898 klassOop instanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
  1899                                                      symbolOop& simple_name_result, TRAPS) {
  1900   ...
  1902 */
  1904 // tell if two classes have the same enclosing class (at package level)
  1905 bool instanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
  1906                                                 klassOop class2_oop, TRAPS) {
  1907   if (class2_oop == class1->as_klassOop())          return true;
  1908   if (!Klass::cast(class2_oop)->oop_is_instance())  return false;
  1909   instanceKlassHandle class2(THREAD, class2_oop);
  1911   // must be in same package before we try anything else
  1912   if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
  1913     return false;
  1915   // As long as there is an outer1.getEnclosingClass,
  1916   // shift the search outward.
  1917   instanceKlassHandle outer1 = class1;
  1918   for (;;) {
  1919     // As we walk along, look for equalities between outer1 and class2.
  1920     // Eventually, the walks will terminate as outer1 stops
  1921     // at the top-level class around the original class.
  1922     symbolOop ignore_name;
  1923     klassOop next = outer1->compute_enclosing_class(ignore_name, CHECK_false);
  1924     if (next == NULL)  break;
  1925     if (next == class2())  return true;
  1926     outer1 = instanceKlassHandle(THREAD, next);
  1929   // Now do the same for class2.
  1930   instanceKlassHandle outer2 = class2;
  1931   for (;;) {
  1932     symbolOop ignore_name;
  1933     klassOop next = outer2->compute_enclosing_class(ignore_name, CHECK_false);
  1934     if (next == NULL)  break;
  1935     // Might as well check the new outer against all available values.
  1936     if (next == class1())  return true;
  1937     if (next == outer1())  return true;
  1938     outer2 = instanceKlassHandle(THREAD, next);
  1941   // If by this point we have not found an equality between the
  1942   // two classes, we know they are in separate package members.
  1943   return false;
  1947 jint instanceKlass::compute_modifier_flags(TRAPS) const {
  1948   klassOop k = as_klassOop();
  1949   jint access = access_flags().as_int();
  1951   // But check if it happens to be member class.
  1952   typeArrayOop inner_class_list = inner_classes();
  1953   int length = (inner_class_list == NULL) ? 0 : inner_class_list->length();
  1954   assert (length % instanceKlass::inner_class_next_offset == 0, "just checking");
  1955   if (length > 0) {
  1956     typeArrayHandle inner_class_list_h(THREAD, inner_class_list);
  1957     instanceKlassHandle ik(THREAD, k);
  1958     for (int i = 0; i < length; i += instanceKlass::inner_class_next_offset) {
  1959       int ioff = inner_class_list_h->ushort_at(
  1960                       i + instanceKlass::inner_class_inner_class_info_offset);
  1962       // Inner class attribute can be zero, skip it.
  1963       // Strange but true:  JVM spec. allows null inner class refs.
  1964       if (ioff == 0) continue;
  1966       // only look at classes that are already loaded
  1967       // since we are looking for the flags for our self.
  1968       symbolOop inner_name = ik->constants()->klass_name_at(ioff);
  1969       if ((ik->name() == inner_name)) {
  1970         // This is really a member class.
  1971         access = inner_class_list_h->ushort_at(i + instanceKlass::inner_class_access_flags_offset);
  1972         break;
  1976   // Remember to strip ACC_SUPER bit
  1977   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
  1980 jint instanceKlass::jvmti_class_status() const {
  1981   jint result = 0;
  1983   if (is_linked()) {
  1984     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
  1987   if (is_initialized()) {
  1988     assert(is_linked(), "Class status is not consistent");
  1989     result |= JVMTI_CLASS_STATUS_INITIALIZED;
  1991   if (is_in_error_state()) {
  1992     result |= JVMTI_CLASS_STATUS_ERROR;
  1994   return result;
  1997 methodOop instanceKlass::method_at_itable(klassOop holder, int index, TRAPS) {
  1998   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
  1999   int method_table_offset_in_words = ioe->offset()/wordSize;
  2000   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
  2001                        / itableOffsetEntry::size();
  2003   for (int cnt = 0 ; ; cnt ++, ioe ++) {
  2004     // If the interface isn't implemented by the receiver class,
  2005     // the VM should throw IncompatibleClassChangeError.
  2006     if (cnt >= nof_interfaces) {
  2007       THROW_OOP_0(vmSymbols::java_lang_IncompatibleClassChangeError());
  2010     klassOop ik = ioe->interface_klass();
  2011     if (ik == holder) break;
  2014   itableMethodEntry* ime = ioe->first_method_entry(as_klassOop());
  2015   methodOop m = ime[index].method();
  2016   if (m == NULL) {
  2017     THROW_OOP_0(vmSymbols::java_lang_AbstractMethodError());
  2019   return m;
  2022 // On-stack replacement stuff
  2023 void instanceKlass::add_osr_nmethod(nmethod* n) {
  2024   // only one compilation can be active
  2025   NEEDS_CLEANUP
  2026   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2027   OsrList_lock->lock_without_safepoint_check();
  2028   assert(n->is_osr_method(), "wrong kind of nmethod");
  2029   n->set_link(osr_nmethods_head());
  2030   set_osr_nmethods_head(n);
  2031   // Remember to unlock again
  2032   OsrList_lock->unlock();
  2036 void instanceKlass::remove_osr_nmethod(nmethod* n) {
  2037   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2038   OsrList_lock->lock_without_safepoint_check();
  2039   assert(n->is_osr_method(), "wrong kind of nmethod");
  2040   nmethod* last = NULL;
  2041   nmethod* cur  = osr_nmethods_head();
  2042   // Search for match
  2043   while(cur != NULL && cur != n) {
  2044     last = cur;
  2045     cur = cur->link();
  2047   if (cur == n) {
  2048     if (last == NULL) {
  2049       // Remove first element
  2050       set_osr_nmethods_head(osr_nmethods_head()->link());
  2051     } else {
  2052       last->set_link(cur->link());
  2055   n->set_link(NULL);
  2056   // Remember to unlock again
  2057   OsrList_lock->unlock();
  2060 nmethod* instanceKlass::lookup_osr_nmethod(const methodOop m, int bci) const {
  2061   // This is a short non-blocking critical region, so the no safepoint check is ok.
  2062   OsrList_lock->lock_without_safepoint_check();
  2063   nmethod* osr = osr_nmethods_head();
  2064   while (osr != NULL) {
  2065     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
  2066     if (osr->method() == m &&
  2067         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
  2068       // Found a match - return it.
  2069       OsrList_lock->unlock();
  2070       return osr;
  2072     osr = osr->link();
  2074   OsrList_lock->unlock();
  2075   return NULL;
  2078 // -----------------------------------------------------------------------------------------------------
  2079 #ifndef PRODUCT
  2081 // Printing
  2083 #define BULLET  " - "
  2085 void FieldPrinter::do_field(fieldDescriptor* fd) {
  2086   _st->print(BULLET);
  2087    if (fd->is_static() || (_obj == NULL)) {
  2088      fd->print_on(_st);
  2089      _st->cr();
  2090    } else {
  2091      fd->print_on_for(_st, _obj);
  2092      _st->cr();
  2097 void instanceKlass::oop_print_on(oop obj, outputStream* st) {
  2098   Klass::oop_print_on(obj, st);
  2100   if (as_klassOop() == SystemDictionary::string_klass()) {
  2101     typeArrayOop value  = java_lang_String::value(obj);
  2102     juint        offset = java_lang_String::offset(obj);
  2103     juint        length = java_lang_String::length(obj);
  2104     if (value != NULL &&
  2105         value->is_typeArray() &&
  2106         offset          <= (juint) value->length() &&
  2107         offset + length <= (juint) value->length()) {
  2108       st->print(BULLET"string: ");
  2109       Handle h_obj(obj);
  2110       java_lang_String::print(h_obj, st);
  2111       st->cr();
  2112       if (!WizardMode)  return;  // that is enough
  2116   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
  2117   FieldPrinter print_nonstatic_field(st, obj);
  2118   do_nonstatic_fields(&print_nonstatic_field);
  2120   if (as_klassOop() == SystemDictionary::class_klass()) {
  2121     st->print(BULLET"signature: ");
  2122     java_lang_Class::print_signature(obj, st);
  2123     st->cr();
  2124     klassOop mirrored_klass = java_lang_Class::as_klassOop(obj);
  2125     st->print(BULLET"fake entry for mirror: ");
  2126     mirrored_klass->print_value_on(st);
  2127     st->cr();
  2128     st->print(BULLET"fake entry resolved_constructor: ");
  2129     methodOop ctor = java_lang_Class::resolved_constructor(obj);
  2130     ctor->print_value_on(st);
  2131     klassOop array_klass = java_lang_Class::array_klass(obj);
  2132     st->cr();
  2133     st->print(BULLET"fake entry for array: ");
  2134     array_klass->print_value_on(st);
  2135     st->cr();
  2139 void instanceKlass::oop_print_value_on(oop obj, outputStream* st) {
  2140   st->print("a ");
  2141   name()->print_value_on(st);
  2142   obj->print_address_on(st);
  2143   if (as_klassOop() == SystemDictionary::string_klass()
  2144       && java_lang_String::value(obj) != NULL) {
  2145     ResourceMark rm;
  2146     int len = java_lang_String::length(obj);
  2147     int plen = (len < 24 ? len : 12);
  2148     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
  2149     st->print(" = \"%s\"", str);
  2150     if (len > plen)
  2151       st->print("...[%d]", len);
  2152   } else if (as_klassOop() == SystemDictionary::class_klass()) {
  2153     klassOop k = java_lang_Class::as_klassOop(obj);
  2154     st->print(" = ");
  2155     if (k != NULL) {
  2156       k->print_value_on(st);
  2157     } else {
  2158       const char* tname = type2name(java_lang_Class::primitive_type(obj));
  2159       st->print("%s", tname ? tname : "type?");
  2161   } else if (java_lang_boxing_object::is_instance(obj)) {
  2162     st->print(" = ");
  2163     java_lang_boxing_object::print(obj, st);
  2167 #endif // ndef PRODUCT
  2169 const char* instanceKlass::internal_name() const {
  2170   return external_name();
  2173 // Verification
  2175 class VerifyFieldClosure: public OopClosure {
  2176  protected:
  2177   template <class T> void do_oop_work(T* p) {
  2178     guarantee(Universe::heap()->is_in_closed_subset(p), "should be in heap");
  2179     oop obj = oopDesc::load_decode_heap_oop(p);
  2180     if (!obj->is_oop_or_null()) {
  2181       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
  2182       Universe::print();
  2183       guarantee(false, "boom");
  2186  public:
  2187   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
  2188   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
  2189 };
  2191 void instanceKlass::oop_verify_on(oop obj, outputStream* st) {
  2192   Klass::oop_verify_on(obj, st);
  2193   VerifyFieldClosure blk;
  2194   oop_oop_iterate(obj, &blk);
  2197 #ifndef PRODUCT
  2199 void instanceKlass::verify_class_klass_nonstatic_oop_maps(klassOop k) {
  2200   // This verification code is disabled.  JDK_Version::is_gte_jdk14x_version()
  2201   // cannot be called since this function is called before the VM is
  2202   // able to determine what JDK version is running with.
  2203   // The check below always is false since 1.4.
  2204   return;
  2206   // This verification code temporarily disabled for the 1.4
  2207   // reflection implementation since java.lang.Class now has
  2208   // Java-level instance fields. Should rewrite this to handle this
  2209   // case.
  2210   if (!(JDK_Version::is_gte_jdk14x_version() && UseNewReflection)) {
  2211     // Verify that java.lang.Class instances have a fake oop field added.
  2212     instanceKlass* ik = instanceKlass::cast(k);
  2214     // Check that we have the right class
  2215     static bool first_time = true;
  2216     guarantee(k == SystemDictionary::class_klass() && first_time, "Invalid verify of maps");
  2217     first_time = false;
  2218     const int extra = java_lang_Class::number_of_fake_oop_fields;
  2219     guarantee(ik->nonstatic_field_size() == extra, "just checking");
  2220     guarantee(ik->nonstatic_oop_map_size() == 1, "just checking");
  2221     guarantee(ik->size_helper() == align_object_size(instanceOopDesc::header_size() + extra), "just checking");
  2223     // Check that the map is (2,extra)
  2224     int offset = java_lang_Class::klass_offset;
  2226     OopMapBlock* map = ik->start_of_nonstatic_oop_maps();
  2227     guarantee(map->offset() == offset && map->length() == extra, "just checking");
  2231 #endif // ndef PRODUCT
  2233 // JNIid class for jfieldIDs only
  2234 // Note to reviewers:
  2235 // These JNI functions are just moved over to column 1 and not changed
  2236 // in the compressed oops workspace.
  2237 JNIid::JNIid(klassOop holder, int offset, JNIid* next) {
  2238   _holder = holder;
  2239   _offset = offset;
  2240   _next = next;
  2241   debug_only(_is_static_field_id = false;)
  2245 JNIid* JNIid::find(int offset) {
  2246   JNIid* current = this;
  2247   while (current != NULL) {
  2248     if (current->offset() == offset) return current;
  2249     current = current->next();
  2251   return NULL;
  2254 void JNIid::oops_do(OopClosure* f) {
  2255   for (JNIid* cur = this; cur != NULL; cur = cur->next()) {
  2256     f->do_oop(cur->holder_addr());
  2260 void JNIid::deallocate(JNIid* current) {
  2261   while (current != NULL) {
  2262     JNIid* next = current->next();
  2263     delete current;
  2264     current = next;
  2269 void JNIid::verify(klassOop holder) {
  2270   int first_field_offset  = instanceKlass::cast(holder)->offset_of_static_fields();
  2271   int end_field_offset;
  2272   end_field_offset = first_field_offset + (instanceKlass::cast(holder)->static_field_size() * wordSize);
  2274   JNIid* current = this;
  2275   while (current != NULL) {
  2276     guarantee(current->holder() == holder, "Invalid klass in JNIid");
  2277 #ifdef ASSERT
  2278     int o = current->offset();
  2279     if (current->is_static_field_id()) {
  2280       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
  2282 #endif
  2283     current = current->next();
  2288 #ifdef ASSERT
  2289 void instanceKlass::set_init_state(ClassState state) {
  2290   bool good_state = as_klassOop()->is_shared() ? (_init_state <= state)
  2291                                                : (_init_state < state);
  2292   assert(good_state || state == allocated, "illegal state transition");
  2293   _init_state = state;
  2295 #endif
  2298 // RedefineClasses() support for previous versions:
  2300 // Add an information node that contains weak references to the
  2301 // interesting parts of the previous version of the_class.
  2302 void instanceKlass::add_previous_version(instanceKlassHandle ikh,
  2303        BitMap* emcp_methods, int emcp_method_count) {
  2304   assert(Thread::current()->is_VM_thread(),
  2305          "only VMThread can add previous versions");
  2307   if (_previous_versions == NULL) {
  2308     // This is the first previous version so make some space.
  2309     // Start with 2 elements under the assumption that the class
  2310     // won't be redefined much.
  2311     _previous_versions =  new (ResourceObj::C_HEAP)
  2312                             GrowableArray<PreviousVersionNode *>(2, true);
  2315   // RC_TRACE macro has an embedded ResourceMark
  2316   RC_TRACE(0x00000100, ("adding previous version ref for %s @%d, EMCP_cnt=%d",
  2317     ikh->external_name(), _previous_versions->length(), emcp_method_count));
  2318   constantPoolHandle cp_h(ikh->constants());
  2319   jobject cp_ref;
  2320   if (cp_h->is_shared()) {
  2321     // a shared ConstantPool requires a regular reference; a weak
  2322     // reference would be collectible
  2323     cp_ref = JNIHandles::make_global(cp_h);
  2324   } else {
  2325     cp_ref = JNIHandles::make_weak_global(cp_h);
  2327   PreviousVersionNode * pv_node = NULL;
  2328   objArrayOop old_methods = ikh->methods();
  2330   if (emcp_method_count == 0) {
  2331     // non-shared ConstantPool gets a weak reference
  2332     pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), NULL);
  2333     RC_TRACE(0x00000400,
  2334       ("add: all methods are obsolete; flushing any EMCP weak refs"));
  2335   } else {
  2336     int local_count = 0;
  2337     GrowableArray<jweak>* method_refs = new (ResourceObj::C_HEAP)
  2338       GrowableArray<jweak>(emcp_method_count, true);
  2339     for (int i = 0; i < old_methods->length(); i++) {
  2340       if (emcp_methods->at(i)) {
  2341         // this old method is EMCP so save a weak ref
  2342         methodOop old_method = (methodOop) old_methods->obj_at(i);
  2343         methodHandle old_method_h(old_method);
  2344         jweak method_ref = JNIHandles::make_weak_global(old_method_h);
  2345         method_refs->append(method_ref);
  2346         if (++local_count >= emcp_method_count) {
  2347           // no more EMCP methods so bail out now
  2348           break;
  2352     // non-shared ConstantPool gets a weak reference
  2353     pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), method_refs);
  2356   _previous_versions->append(pv_node);
  2358   // Using weak references allows the interesting parts of previous
  2359   // classes to be GC'ed when they are no longer needed. Since the
  2360   // caller is the VMThread and we are at a safepoint, this is a good
  2361   // time to clear out unused weak references.
  2363   RC_TRACE(0x00000400, ("add: previous version length=%d",
  2364     _previous_versions->length()));
  2366   // skip the last entry since we just added it
  2367   for (int i = _previous_versions->length() - 2; i >= 0; i--) {
  2368     // check the previous versions array for a GC'ed weak refs
  2369     pv_node = _previous_versions->at(i);
  2370     cp_ref = pv_node->prev_constant_pool();
  2371     assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
  2372     if (cp_ref == NULL) {
  2373       delete pv_node;
  2374       _previous_versions->remove_at(i);
  2375       // Since we are traversing the array backwards, we don't have to
  2376       // do anything special with the index.
  2377       continue;  // robustness
  2380     constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
  2381     if (cp == NULL) {
  2382       // this entry has been GC'ed so remove it
  2383       delete pv_node;
  2384       _previous_versions->remove_at(i);
  2385       // Since we are traversing the array backwards, we don't have to
  2386       // do anything special with the index.
  2387       continue;
  2388     } else {
  2389       RC_TRACE(0x00000400, ("add: previous version @%d is alive", i));
  2392     GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
  2393     if (method_refs != NULL) {
  2394       RC_TRACE(0x00000400, ("add: previous methods length=%d",
  2395         method_refs->length()));
  2396       for (int j = method_refs->length() - 1; j >= 0; j--) {
  2397         jweak method_ref = method_refs->at(j);
  2398         assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
  2399         if (method_ref == NULL) {
  2400           method_refs->remove_at(j);
  2401           // Since we are traversing the array backwards, we don't have to
  2402           // do anything special with the index.
  2403           continue;  // robustness
  2406         methodOop method = (methodOop)JNIHandles::resolve(method_ref);
  2407         if (method == NULL || emcp_method_count == 0) {
  2408           // This method entry has been GC'ed or the current
  2409           // RedefineClasses() call has made all methods obsolete
  2410           // so remove it.
  2411           JNIHandles::destroy_weak_global(method_ref);
  2412           method_refs->remove_at(j);
  2413         } else {
  2414           // RC_TRACE macro has an embedded ResourceMark
  2415           RC_TRACE(0x00000400,
  2416             ("add: %s(%s): previous method @%d in version @%d is alive",
  2417             method->name()->as_C_string(), method->signature()->as_C_string(),
  2418             j, i));
  2424   int obsolete_method_count = old_methods->length() - emcp_method_count;
  2426   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
  2427       _previous_versions->length() > 1) {
  2428     // We have a mix of obsolete and EMCP methods. If there is more
  2429     // than the previous version that we just added, then we have to
  2430     // clear out any matching EMCP method entries the hard way.
  2431     int local_count = 0;
  2432     for (int i = 0; i < old_methods->length(); i++) {
  2433       if (!emcp_methods->at(i)) {
  2434         // only obsolete methods are interesting
  2435         methodOop old_method = (methodOop) old_methods->obj_at(i);
  2436         symbolOop m_name = old_method->name();
  2437         symbolOop m_signature = old_method->signature();
  2439         // skip the last entry since we just added it
  2440         for (int j = _previous_versions->length() - 2; j >= 0; j--) {
  2441           // check the previous versions array for a GC'ed weak refs
  2442           pv_node = _previous_versions->at(j);
  2443           cp_ref = pv_node->prev_constant_pool();
  2444           assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
  2445           if (cp_ref == NULL) {
  2446             delete pv_node;
  2447             _previous_versions->remove_at(j);
  2448             // Since we are traversing the array backwards, we don't have to
  2449             // do anything special with the index.
  2450             continue;  // robustness
  2453           constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
  2454           if (cp == NULL) {
  2455             // this entry has been GC'ed so remove it
  2456             delete pv_node;
  2457             _previous_versions->remove_at(j);
  2458             // Since we are traversing the array backwards, we don't have to
  2459             // do anything special with the index.
  2460             continue;
  2463           GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
  2464           if (method_refs == NULL) {
  2465             // We have run into a PreviousVersion generation where
  2466             // all methods were made obsolete during that generation's
  2467             // RedefineClasses() operation. At the time of that
  2468             // operation, all EMCP methods were flushed so we don't
  2469             // have to go back any further.
  2470             //
  2471             // A NULL method_refs is different than an empty method_refs.
  2472             // We cannot infer any optimizations about older generations
  2473             // from an empty method_refs for the current generation.
  2474             break;
  2477           for (int k = method_refs->length() - 1; k >= 0; k--) {
  2478             jweak method_ref = method_refs->at(k);
  2479             assert(method_ref != NULL,
  2480               "weak method ref was unexpectedly cleared");
  2481             if (method_ref == NULL) {
  2482               method_refs->remove_at(k);
  2483               // Since we are traversing the array backwards, we don't
  2484               // have to do anything special with the index.
  2485               continue;  // robustness
  2488             methodOop method = (methodOop)JNIHandles::resolve(method_ref);
  2489             if (method == NULL) {
  2490               // this method entry has been GC'ed so skip it
  2491               JNIHandles::destroy_weak_global(method_ref);
  2492               method_refs->remove_at(k);
  2493               continue;
  2496             if (method->name() == m_name &&
  2497                 method->signature() == m_signature) {
  2498               // The current RedefineClasses() call has made all EMCP
  2499               // versions of this method obsolete so mark it as obsolete
  2500               // and remove the weak ref.
  2501               RC_TRACE(0x00000400,
  2502                 ("add: %s(%s): flush obsolete method @%d in version @%d",
  2503                 m_name->as_C_string(), m_signature->as_C_string(), k, j));
  2505               method->set_is_obsolete();
  2506               JNIHandles::destroy_weak_global(method_ref);
  2507               method_refs->remove_at(k);
  2508               break;
  2512           // The previous loop may not find a matching EMCP method, but
  2513           // that doesn't mean that we can optimize and not go any
  2514           // further back in the PreviousVersion generations. The EMCP
  2515           // method for this generation could have already been GC'ed,
  2516           // but there still may be an older EMCP method that has not
  2517           // been GC'ed.
  2520         if (++local_count >= obsolete_method_count) {
  2521           // no more obsolete methods so bail out now
  2522           break;
  2527 } // end add_previous_version()
  2530 // Determine if instanceKlass has a previous version.
  2531 bool instanceKlass::has_previous_version() const {
  2532   if (_previous_versions == NULL) {
  2533     // no previous versions array so answer is easy
  2534     return false;
  2537   for (int i = _previous_versions->length() - 1; i >= 0; i--) {
  2538     // Check the previous versions array for an info node that hasn't
  2539     // been GC'ed
  2540     PreviousVersionNode * pv_node = _previous_versions->at(i);
  2542     jobject cp_ref = pv_node->prev_constant_pool();
  2543     assert(cp_ref != NULL, "cp reference was unexpectedly cleared");
  2544     if (cp_ref == NULL) {
  2545       continue;  // robustness
  2548     constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
  2549     if (cp != NULL) {
  2550       // we have at least one previous version
  2551       return true;
  2554     // We don't have to check the method refs. If the constant pool has
  2555     // been GC'ed then so have the methods.
  2558   // all of the underlying nodes' info has been GC'ed
  2559   return false;
  2560 } // end has_previous_version()
  2562 methodOop instanceKlass::method_with_idnum(int idnum) {
  2563   methodOop m = NULL;
  2564   if (idnum < methods()->length()) {
  2565     m = (methodOop) methods()->obj_at(idnum);
  2567   if (m == NULL || m->method_idnum() != idnum) {
  2568     for (int index = 0; index < methods()->length(); ++index) {
  2569       m = (methodOop) methods()->obj_at(index);
  2570       if (m->method_idnum() == idnum) {
  2571         return m;
  2575   return m;
  2579 // Set the annotation at 'idnum' to 'anno'.
  2580 // We don't want to create or extend the array if 'anno' is NULL, since that is the
  2581 // default value.  However, if the array exists and is long enough, we must set NULL values.
  2582 void instanceKlass::set_methods_annotations_of(int idnum, typeArrayOop anno, objArrayOop* md_p) {
  2583   objArrayOop md = *md_p;
  2584   if (md != NULL && md->length() > idnum) {
  2585     md->obj_at_put(idnum, anno);
  2586   } else if (anno != NULL) {
  2587     // create the array
  2588     int length = MAX2(idnum+1, (int)_idnum_allocated_count);
  2589     md = oopFactory::new_system_objArray(length, Thread::current());
  2590     if (*md_p != NULL) {
  2591       // copy the existing entries
  2592       for (int index = 0; index < (*md_p)->length(); index++) {
  2593         md->obj_at_put(index, (*md_p)->obj_at(index));
  2596     set_annotations(md, md_p);
  2597     md->obj_at_put(idnum, anno);
  2598   } // if no array and idnum isn't included there is nothing to do
  2601 // Construct a PreviousVersionNode entry for the array hung off
  2602 // the instanceKlass.
  2603 PreviousVersionNode::PreviousVersionNode(jobject prev_constant_pool,
  2604   bool prev_cp_is_weak, GrowableArray<jweak>* prev_EMCP_methods) {
  2606   _prev_constant_pool = prev_constant_pool;
  2607   _prev_cp_is_weak = prev_cp_is_weak;
  2608   _prev_EMCP_methods = prev_EMCP_methods;
  2612 // Destroy a PreviousVersionNode
  2613 PreviousVersionNode::~PreviousVersionNode() {
  2614   if (_prev_constant_pool != NULL) {
  2615     if (_prev_cp_is_weak) {
  2616       JNIHandles::destroy_weak_global(_prev_constant_pool);
  2617     } else {
  2618       JNIHandles::destroy_global(_prev_constant_pool);
  2622   if (_prev_EMCP_methods != NULL) {
  2623     for (int i = _prev_EMCP_methods->length() - 1; i >= 0; i--) {
  2624       jweak method_ref = _prev_EMCP_methods->at(i);
  2625       if (method_ref != NULL) {
  2626         JNIHandles::destroy_weak_global(method_ref);
  2629     delete _prev_EMCP_methods;
  2634 // Construct a PreviousVersionInfo entry
  2635 PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
  2636   _prev_constant_pool_handle = constantPoolHandle();  // NULL handle
  2637   _prev_EMCP_method_handles = NULL;
  2639   jobject cp_ref = pv_node->prev_constant_pool();
  2640   assert(cp_ref != NULL, "constant pool ref was unexpectedly cleared");
  2641   if (cp_ref == NULL) {
  2642     return;  // robustness
  2645   constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
  2646   if (cp == NULL) {
  2647     // Weak reference has been GC'ed. Since the constant pool has been
  2648     // GC'ed, the methods have also been GC'ed.
  2649     return;
  2652   // make the constantPoolOop safe to return
  2653   _prev_constant_pool_handle = constantPoolHandle(cp);
  2655   GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
  2656   if (method_refs == NULL) {
  2657     // the instanceKlass did not have any EMCP methods
  2658     return;
  2661   _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
  2663   int n_methods = method_refs->length();
  2664   for (int i = 0; i < n_methods; i++) {
  2665     jweak method_ref = method_refs->at(i);
  2666     assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
  2667     if (method_ref == NULL) {
  2668       continue;  // robustness
  2671     methodOop method = (methodOop)JNIHandles::resolve(method_ref);
  2672     if (method == NULL) {
  2673       // this entry has been GC'ed so skip it
  2674       continue;
  2677     // make the methodOop safe to return
  2678     _prev_EMCP_method_handles->append(methodHandle(method));
  2683 // Destroy a PreviousVersionInfo
  2684 PreviousVersionInfo::~PreviousVersionInfo() {
  2685   // Since _prev_EMCP_method_handles is not C-heap allocated, we
  2686   // don't have to delete it.
  2690 // Construct a helper for walking the previous versions array
  2691 PreviousVersionWalker::PreviousVersionWalker(instanceKlass *ik) {
  2692   _previous_versions = ik->previous_versions();
  2693   _current_index = 0;
  2694   // _hm needs no initialization
  2695   _current_p = NULL;
  2699 // Destroy a PreviousVersionWalker
  2700 PreviousVersionWalker::~PreviousVersionWalker() {
  2701   // Delete the current info just in case the caller didn't walk to
  2702   // the end of the previous versions list. No harm if _current_p is
  2703   // already NULL.
  2704   delete _current_p;
  2706   // When _hm is destroyed, all the Handles returned in
  2707   // PreviousVersionInfo objects will be destroyed.
  2708   // Also, after this destructor is finished it will be
  2709   // safe to delete the GrowableArray allocated in the
  2710   // PreviousVersionInfo objects.
  2714 // Return the interesting information for the next previous version
  2715 // of the klass. Returns NULL if there are no more previous versions.
  2716 PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
  2717   if (_previous_versions == NULL) {
  2718     // no previous versions so nothing to return
  2719     return NULL;
  2722   delete _current_p;  // cleanup the previous info for the caller
  2723   _current_p = NULL;  // reset to NULL so we don't delete same object twice
  2725   int length = _previous_versions->length();
  2727   while (_current_index < length) {
  2728     PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
  2729     PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP)
  2730                                           PreviousVersionInfo(pv_node);
  2732     constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
  2733     if (cp_h.is_null()) {
  2734       delete pv_info;
  2736       // The underlying node's info has been GC'ed so try the next one.
  2737       // We don't have to check the methods. If the constant pool has
  2738       // GC'ed then so have the methods.
  2739       continue;
  2742     // Found a node with non GC'ed info so return it. The caller will
  2743     // need to delete pv_info when they are done with it.
  2744     _current_p = pv_info;
  2745     return pv_info;
  2748   // all of the underlying nodes' info has been GC'ed
  2749   return NULL;
  2750 } // end next_previous_version()

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