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 /*

  * Copyright (c) 1998, 2012, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

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  */

 #include "precompiled.hpp"

 #include "gc_implementation/shared/markSweep.inline.hpp"

 #include "interpreter/interpreter.hpp"

 #include "interpreter/rewriter.hpp"

 #include "memory/universe.inline.hpp"

 #include "oops/cpCacheOop.hpp"

 #include "oops/objArrayOop.hpp"

 #include "oops/oop.inline.hpp"

 #include "prims/jvmtiRedefineClassesTrace.hpp"

 #include "prims/methodHandles.hpp"

 #include "runtime/handles.inline.hpp"

 // Implememtation of ConstantPoolCacheEntry

 void ConstantPoolCacheEntry::initialize_entry(int index) {

   assert(0 < index && index < 0x10000, "sanity check");

   _indices = index;

   assert(constant_pool_index() == index, "");

 }

 void ConstantPoolCacheEntry::initialize_secondary_entry(int main_index) {

   assert(0 <= main_index && main_index < 0x10000, "sanity check");

   _indices = (main_index << main_cp_index_bits);

   assert(main_entry_index() == main_index, "");

 }

 int ConstantPoolCacheEntry::make_flags(TosState state,

                                        int option_bits,

                                        int field_index_or_method_params) {

   assert(state < number_of_states, "Invalid state in make_flags");

   int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params;

   // Preserve existing flag bit values

   // The low bits are a field offset, or else the method parameter size.

 #ifdef ASSERT

   TosState old_state = flag_state();

   assert(old_state == (TosState)0 || old_state == state,

          "inconsistent cpCache flags state");

 #endif

   return (_flags | f) ;

 }

 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) {

   assert(!is_secondary_entry(), "must not overwrite main_entry_index");

 #ifdef ASSERT

   // Read once.

   volatile Bytecodes::Code c = bytecode_1();

   assert(c == 0 || c == code || code == 0, "update must be consistent");

 #endif

   // Need to flush pending stores here before bytecode is written.

   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_1_shift));

 }

 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {

   assert(!is_secondary_entry(), "must not overwrite main_entry_index");

 #ifdef ASSERT

   // Read once.

   volatile Bytecodes::Code c = bytecode_2();

   assert(c == 0 || c == code || code == 0, "update must be consistent");

 #endif

   // Need to flush pending stores here before bytecode is written.

   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_2_shift));

 }

 // Sets f1, ordering with previous writes.

 void ConstantPoolCacheEntry::release_set_f1(oop f1) {

   // Use barriers as in oop_store

   assert(f1 != NULL, "");

   oop* f1_addr = (oop*) &_f1;

   update_barrier_set_pre(f1_addr, f1);

   OrderAccess::release_store_ptr((intptr_t*)f1_addr, f1);

   update_barrier_set((void*) f1_addr, f1);

 }

 // Sets flags, but only if the value was previously zero.

 bool ConstantPoolCacheEntry::init_flags_atomic(intptr_t flags) {

   intptr_t result = Atomic::cmpxchg_ptr(flags, &_flags, 0);

   return (result == 0);

 }

 #ifdef ASSERT

 // It is possible to have two different dummy methodOops created

 // when the resolve code for invoke interface executes concurrently

 // Hence the assertion below is weakened a bit for the invokeinterface

 // case.

 bool ConstantPoolCacheEntry::same_methodOop(oop cur_f1, oop f1) {

   return (cur_f1 == f1 || ((methodOop)cur_f1)->name() ==

          ((methodOop)f1)->name() || ((methodOop)cur_f1)->signature() ==

          ((methodOop)f1)->signature());

 }

 #endif

 // Note that concurrent update of both bytecodes can leave one of them

 // reset to zero.  This is harmless; the interpreter will simply re-resolve

 // the damaged entry.  More seriously, the memory synchronization is needed

 // to flush other fields (f1, f2) completely to memory before the bytecodes

 // are updated, lest other processors see a non-zero bytecode but zero f1/f2.

 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code,

                                        Bytecodes::Code put_code,

                                        KlassHandle field_holder,

                                        int field_index,

                                        int field_offset,

                                        TosState field_type,

                                        bool is_final,

                                        bool is_volatile) {

   set_f1(field_holder()->java_mirror());

   set_f2(field_offset);

   assert((field_index & field_index_mask) == field_index,

          "field index does not fit in low flag bits");

   set_field_flags(field_type,

                   ((is_volatile ? 1 : 0) << is_volatile_shift) |

                   ((is_final    ? 1 : 0) << is_final_shift),

                   field_index);

   set_bytecode_1(get_code);

   set_bytecode_2(put_code);

   NOT_PRODUCT(verify(tty));

 }

 void ConstantPoolCacheEntry::set_parameter_size(int value) {

   // This routine is called only in corner cases where the CPCE is not yet initialized.

   // See AbstractInterpreter::deopt_continue_after_entry.

   assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value,

          err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value));

   // Setting the parameter size by itself is only safe if the

   // current value of _flags is 0, otherwise another thread may have

   // updated it and we don't want to overwrite that value.  Don't

   // bother trying to update it once it's nonzero but always make

   // sure that the final parameter size agrees with what was passed.

   if (_flags == 0) {

     Atomic::cmpxchg_ptr((value & parameter_size_mask), &_flags, 0);

   }

   guarantee(parameter_size() == value,

             err_msg("size must not change: parameter_size=%d, value=%d", parameter_size(), value));

 }

 void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,

                                         methodHandle method,

                                         int vtable_index) {

   assert(!is_secondary_entry(), "");

   assert(method->interpreter_entry() != NULL, "should have been set at this point");

   assert(!method->is_obsolete(),  "attempt to write obsolete method to cpCache");

   int byte_no = -1;

   bool change_to_virtual = false;

   switch (invoke_code) {

     case Bytecodes::_invokeinterface:

       // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface

       // instruction somehow links to a non-interface method (in Object).

       // In that case, the method has no itable index and must be invoked as a virtual.

       // Set a flag to keep track of this corner case.

       change_to_virtual = true;

       // ...and fall through as if we were handling invokevirtual:

     case Bytecodes::_invokevirtual:

       {

         if (method->can_be_statically_bound()) {

           // set_f2_as_vfinal_method checks if is_vfinal flag is true.

           set_method_flags(as_TosState(method->result_type()),

                            (                             1      << is_vfinal_shift) |

                            ((method->is_final_method() ? 1 : 0) << is_final_shift)  |

                            ((change_to_virtual         ? 1 : 0) << is_forced_virtual_shift),

                            method()->size_of_parameters());

           set_f2_as_vfinal_method(method());

         } else {

           assert(vtable_index >= 0, "valid index");

           assert(!method->is_final_method(), "sanity");

           set_method_flags(as_TosState(method->result_type()),

                            ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),

                            method()->size_of_parameters());

           set_f2(vtable_index);

         }

         byte_no = 2;

         break;

       }

     case Bytecodes::_invokespecial:

     case Bytecodes::_invokestatic:

       // Note:  Read and preserve the value of the is_vfinal flag on any

       // invokevirtual bytecode shared with this constant pool cache entry.

       // It is cheap and safe to consult is_vfinal() at all times.

       // Once is_vfinal is set, it must stay that way, lest we get a dangling oop.

       set_method_flags(as_TosState(method->result_type()),

                        ((is_vfinal()               ? 1 : 0) << is_vfinal_shift) |

                        ((method->is_final_method() ? 1 : 0) << is_final_shift),

                        method()->size_of_parameters());

       set_f1(method());

       byte_no = 1;

       break;

     default:

       ShouldNotReachHere();

       break;

   }

   // Note:  byte_no also appears in TemplateTable::resolve.

   if (byte_no == 1) {

     assert(invoke_code != Bytecodes::_invokevirtual &&

            invoke_code != Bytecodes::_invokeinterface, "");

     set_bytecode_1(invoke_code);

   } else if (byte_no == 2)  {

     if (change_to_virtual) {

       assert(invoke_code == Bytecodes::_invokeinterface, "");

       // NOTE: THIS IS A HACK - BE VERY CAREFUL!!!

       //

       // Workaround for the case where we encounter an invokeinterface, but we

       // should really have an _invokevirtual since the resolved method is a

       // virtual method in java.lang.Object. This is a corner case in the spec

       // but is presumably legal. javac does not generate this code.

       //

       // We set bytecode_1() to _invokeinterface, because that is the

       // bytecode # used by the interpreter to see if it is resolved.

       // We set bytecode_2() to _invokevirtual.

       // See also interpreterRuntime.cpp. (8/25/2000)

       // Only set resolved for the invokeinterface case if method is public.

       // Otherwise, the method needs to be reresolved with caller for each

       // interface call.

       if (method->is_public()) set_bytecode_1(invoke_code);

     } else {

       assert(invoke_code == Bytecodes::_invokevirtual, "");

     }

     // set up for invokevirtual, even if linking for invokeinterface also:

     set_bytecode_2(Bytecodes::_invokevirtual);

   } else {

     ShouldNotReachHere();

   }

   NOT_PRODUCT(verify(tty));

 }

 void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) {

   assert(!is_secondary_entry(), "");

   klassOop interf = method->method_holder();

   assert(instanceKlass::cast(interf)->is_interface(), "must be an interface");

   assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");

   set_f1(interf);

   set_f2(index);

   set_method_flags(as_TosState(method->result_type()),

                    0,  // no option bits

                    method()->size_of_parameters());

   set_bytecode_1(Bytecodes::_invokeinterface);

 }

 void ConstantPoolCacheEntry::set_method_handle(methodHandle adapter, Handle appendix) {

   assert(!is_secondary_entry(), "");

   set_method_handle_common(Bytecodes::_invokehandle, adapter, appendix);

 }

 void ConstantPoolCacheEntry::set_dynamic_call(methodHandle adapter, Handle appendix) {

   assert(is_secondary_entry(), "");

   set_method_handle_common(Bytecodes::_invokedynamic, adapter, appendix);

 }

 void ConstantPoolCacheEntry::set_method_handle_common(Bytecodes::Code invoke_code, methodHandle adapter, Handle appendix) {

   // NOTE: This CPCE can be the subject of data races.

   // There are three words to update: flags, f2, f1 (in that order).

   // Writers must store all other values before f1.

   // Readers must test f1 first for non-null before reading other fields.

   // Competing writers must acquire exclusive access on the first

   // write, to flags, using a compare/exchange.

   // A losing writer must spin until the winner writes f1,

   // so that when he returns, he can use the linked cache entry.

   bool has_appendix = appendix.not_null();

   if (!has_appendix) {

     // The extra argument is not used, but we need a non-null value to signify linkage state.

     // Set it to something benign that will never leak memory.

     appendix = Universe::void_mirror();

   }

   bool owner =

     init_method_flags_atomic(as_TosState(adapter->result_type()),

                    ((has_appendix ?  1 : 0) << has_appendix_shift) |

                    (                 1      << is_vfinal_shift)    |

                    (                 1      << is_final_shift),

                    adapter->size_of_parameters());

   if (!owner) {

     while (is_f1_null()) {

       // Pause momentarily on a low-level lock, to allow racing thread to win.

       MutexLockerEx mu(Patching_lock, Mutex::_no_safepoint_check_flag);

       os::yield();

     }

     return;

   }

   if (TraceInvokeDynamic) {

     tty->print_cr("set_method_handle bc=%d appendix="PTR_FORMAT"%s method="PTR_FORMAT" ",

                   invoke_code,

                   (intptr_t)appendix(), (has_appendix ? "" : " (unused)"),

                   (intptr_t)adapter());

     adapter->print();

     if (has_appendix)  appendix()->print();

   }

   // Method handle invokes and invokedynamic sites use both cp cache words.

   // f1, if not null, contains a value passed as a trailing argument to the adapter.

   // In the general case, this could be the call site's MethodType,

   // for use with java.lang.Invokers.checkExactType, or else a CallSite object.

   // f2 contains the adapter method which manages the actual call.

   // In the general case, this is a compiled LambdaForm.

   // (The Java code is free to optimize these calls by binding other

   // sorts of methods and appendices to call sites.)

   // JVM-level linking is via f2, as if for invokevfinal, and signatures are erased.

   // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.

   // In principle this means that the method (with appendix) could take up to 256 parameter slots.

   //

   // This means that given a call site like (List)mh.invoke("foo"),

   // the f2 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;',

   // not '(Ljava/lang/String;)Ljava/util/List;'.

   // The fact that String and List are involved is encoded in the MethodType in f1.

   // This allows us to create fewer method oops, while keeping type safety.

   //

   set_f2_as_vfinal_method(adapter());

   assert(appendix.not_null(), "needed for linkage state");

   release_set_f1(appendix());  // This must be the last one to set (see NOTE above)!

   if (!is_secondary_entry()) {

     // The interpreter assembly code does not check byte_2,

     // but it is used by is_resolved, method_if_resolved, etc.

     set_bytecode_2(invoke_code);

   }

   NOT_PRODUCT(verify(tty));

   if (TraceInvokeDynamic) {

     this->print(tty, 0);

   }

 }

 methodOop ConstantPoolCacheEntry::method_if_resolved(constantPoolHandle cpool) {

   if (is_secondary_entry()) {

     if (!is_f1_null())

       return f2_as_vfinal_method();

     return NULL;

   }

   // Decode the action of set_method and set_interface_call

   Bytecodes::Code invoke_code = bytecode_1();

   if (invoke_code != (Bytecodes::Code)0) {

     oop f1 = _f1;

     if (f1 != NULL) {

       switch (invoke_code) {

       case Bytecodes::_invokeinterface:

         assert(f1->is_klass(), "");

         return klassItable::method_for_itable_index(klassOop(f1), f2_as_index());

       case Bytecodes::_invokestatic:

       case Bytecodes::_invokespecial:

         assert(!has_appendix(), "");

         assert(f1->is_method(), "");

         return methodOop(f1);

       }

     }

   }

   invoke_code = bytecode_2();

   if (invoke_code != (Bytecodes::Code)0) {

     switch (invoke_code) {

     case Bytecodes::_invokevirtual:

       if (is_vfinal()) {

         // invokevirtual

         methodOop m = f2_as_vfinal_method();

         assert(m->is_method(), "");

         return m;

       } else {

         int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index());

         if (cpool->tag_at(holder_index).is_klass()) {

           klassOop klass = cpool->resolved_klass_at(holder_index);

           if (!Klass::cast(klass)->oop_is_instance())

             klass = SystemDictionary::Object_klass();

           return instanceKlass::cast(klass)->method_at_vtable(f2_as_index());

         }

       }

       break;

     case Bytecodes::_invokehandle:

     case Bytecodes::_invokedynamic:

       return f2_as_vfinal_method();

     }

   }

   return NULL;

 }

 class LocalOopClosure: public OopClosure {

  private:

   void (*_f)(oop*);

  public:

   LocalOopClosure(void f(oop*))        { _f = f; }

   virtual void do_oop(oop* o)          { _f(o); }

   virtual void do_oop(narrowOop *o)    { ShouldNotReachHere(); }

 };

 void ConstantPoolCacheEntry::oops_do(void f(oop*)) {

   LocalOopClosure blk(f);

   oop_iterate(&blk);

 }

 void ConstantPoolCacheEntry::oop_iterate(OopClosure* blk) {

   assert(in_words(size()) == 4, "check code below - may need adjustment");

   // field[1] is always oop or NULL

   blk->do_oop((oop*)&_f1);

   if (is_vfinal()) {

     blk->do_oop((oop*)&_f2);

   }

 }

 void ConstantPoolCacheEntry::oop_iterate_m(OopClosure* blk, MemRegion mr) {

   assert(in_words(size()) == 4, "check code below - may need adjustment");

   // field[1] is always oop or NULL

   if (mr.contains((oop *)&_f1)) blk->do_oop((oop*)&_f1);

   if (is_vfinal()) {

     if (mr.contains((oop *)&_f2)) blk->do_oop((oop*)&_f2);

   }

 }

 void ConstantPoolCacheEntry::follow_contents() {

   assert(in_words(size()) == 4, "check code below - may need adjustment");

   // field[1] is always oop or NULL

   MarkSweep::mark_and_push((oop*)&_f1);

   if (is_vfinal()) {

     MarkSweep::mark_and_push((oop*)&_f2);

   }

 }

 #ifndef SERIALGC

 void ConstantPoolCacheEntry::follow_contents(ParCompactionManager* cm) {

   assert(in_words(size()) == 4, "check code below - may need adjustment");

   // field[1] is always oop or NULL

   PSParallelCompact::mark_and_push(cm, (oop*)&_f1);

   if (is_vfinal()) {

     PSParallelCompact::mark_and_push(cm, (oop*)&_f2);

   }

 }

 #endif // SERIALGC

 void ConstantPoolCacheEntry::adjust_pointers() {

   assert(in_words(size()) == 4, "check code below - may need adjustment");

   // field[1] is always oop or NULL

   MarkSweep::adjust_pointer((oop*)&_f1);

   if (is_vfinal()) {

     MarkSweep::adjust_pointer((oop*)&_f2);

   }

 }

 #ifndef SERIALGC

 void ConstantPoolCacheEntry::update_pointers() {

   assert(in_words(size()) == 4, "check code below - may need adjustment");

   // field[1] is always oop or NULL

   PSParallelCompact::adjust_pointer((oop*)&_f1);

   if (is_vfinal()) {

     PSParallelCompact::adjust_pointer((oop*)&_f2);

   }

 }

 #endif // SERIALGC

 // RedefineClasses() API support:

 // If this constantPoolCacheEntry refers to old_method then update it

 // to refer to new_method.

 bool ConstantPoolCacheEntry::adjust_method_entry(methodOop old_method,

        methodOop new_method, bool * trace_name_printed) {

   if (is_vfinal()) {

     // virtual and final so _f2 contains method ptr instead of vtable index

     if (f2_as_vfinal_method() == old_method) {

       // match old_method so need an update

       // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values

       _f2 = (intptr_t)new_method;

       if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {

         if (!(*trace_name_printed)) {

           // RC_TRACE_MESG macro has an embedded ResourceMark

           RC_TRACE_MESG(("adjust: name=%s",

             Klass::cast(old_method->method_holder())->external_name()));

           *trace_name_printed = true;

         }

         // RC_TRACE macro has an embedded ResourceMark

         RC_TRACE(0x00400000, ("cpc vf-entry update: %s(%s)",

           new_method->name()->as_C_string(),

           new_method->signature()->as_C_string()));

       }

       return true;

     }

     // f1() is not used with virtual entries so bail out

     return false;

   }

   if ((oop)_f1 == NULL) {

     // NULL f1() means this is a virtual entry so bail out

     // We are assuming that the vtable index does not need change.

     return false;

   }

   if ((oop)_f1 == old_method) {

     _f1 = new_method;

     if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {

       if (!(*trace_name_printed)) {

         // RC_TRACE_MESG macro has an embedded ResourceMark

         RC_TRACE_MESG(("adjust: name=%s",

           Klass::cast(old_method->method_holder())->external_name()));

         *trace_name_printed = true;

       }

       // RC_TRACE macro has an embedded ResourceMark

       RC_TRACE(0x00400000, ("cpc entry update: %s(%s)",

         new_method->name()->as_C_string(),

         new_method->signature()->as_C_string()));

     }

     return true;

   }

   return false;

 }

 bool ConstantPoolCacheEntry::is_interesting_method_entry(klassOop k) {

   if (!is_method_entry()) {

     // not a method entry so not interesting by default

     return false;

   }

   methodOop m = NULL;

   if (is_vfinal()) {

     // virtual and final so _f2 contains method ptr instead of vtable index

     m = f2_as_vfinal_method();

   } else if (is_f1_null()) {

     // NULL _f1 means this is a virtual entry so also not interesting

     return false;

   } else {

     oop f1 = _f1;  // _f1 is volatile

     if (!f1->is_method()) {

       // _f1 can also contain a klassOop for an interface

       return false;

     }

     m = f1_as_method();

   }

   assert(m != NULL && m->is_method(), "sanity check");

   if (m == NULL || !m->is_method() || m->method_holder() != k) {

     // robustness for above sanity checks or method is not in

     // the interesting class

     return false;

   }

   // the method is in the interesting class so the entry is interesting

   return true;

 }

 void ConstantPoolCacheEntry::print(outputStream* st, int index) const {

   // print separator

   if (index == 0) st->print_cr("                 -------------");

   // print entry

   st->print("%3d  ("PTR_FORMAT")  ", index, (intptr_t)this);

   if (is_secondary_entry())

     st->print_cr("[%5d|secondary]", main_entry_index());

   else

     st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(), constant_pool_index());

   st->print_cr("                 [   "PTR_FORMAT"]", (intptr_t)(oop)_f1);

   st->print_cr("                 [   "PTR_FORMAT"]", (intptr_t)_f2);

   st->print_cr("                 [   "PTR_FORMAT"]", (intptr_t)_flags);

   st->print_cr("                 -------------");

 }

 void ConstantPoolCacheEntry::verify(outputStream* st) const {

   // not implemented yet

 }

 // Implementation of ConstantPoolCache

 void constantPoolCacheOopDesc::initialize(intArray& inverse_index_map) {

   assert(inverse_index_map.length() == length(), "inverse index map must have same length as cache");

   for (int i = 0; i < length(); i++) {

     ConstantPoolCacheEntry* e = entry_at(i);

     int original_index = inverse_index_map[i];

     if ((original_index & Rewriter::_secondary_entry_tag) != 0) {

       int main_index = (original_index - Rewriter::_secondary_entry_tag);

       assert(!entry_at(main_index)->is_secondary_entry(), "valid main index");

       e->initialize_secondary_entry(main_index);

     } else {

       e->initialize_entry(original_index);

     }

     assert(entry_at(i) == e, "sanity");

   }

 }

 // RedefineClasses() API support:

 // If any entry of this constantPoolCache points to any of

 // old_methods, replace it with the corresponding new_method.

 void constantPoolCacheOopDesc::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,

                                                      int methods_length, bool * trace_name_printed) {

   if (methods_length == 0) {

     // nothing to do if there are no methods

     return;

   }

   // get shorthand for the interesting class

   klassOop old_holder = old_methods[0]->method_holder();

   for (int i = 0; i < length(); i++) {

     if (!entry_at(i)->is_interesting_method_entry(old_holder)) {

       // skip uninteresting methods

       continue;

     }

     // The constantPoolCache contains entries for several different

     // things, but we only care about methods. In fact, we only care

     // about methods in the same class as the one that contains the

     // old_methods. At this point, we have an interesting entry.

     for (int j = 0; j < methods_length; j++) {

       methodOop old_method = old_methods[j];

       methodOop new_method = new_methods[j];

       if (entry_at(i)->adjust_method_entry(old_method, new_method,

           trace_name_printed)) {

         // current old_method matched this entry and we updated it so

         // break out and get to the next interesting entry if there one

         break;

       }

     }

   }

 }