8365501: Remove special AdapterHandlerEntry for abstract methods

Reviewed-by: kvn, adinn

src/hotspot/share/cds/archiveBuilder.cpp

@@ -563,12 +563,7 @@ ArchiveBuilder::FollowMode ArchiveBuilder::get_follow_mode(MetaspaceClosure::Ref
              ref->msotype() == MetaspaceObj::CompileTrainingDataType) {
     return (TrainingData::need_data() || TrainingData::assembling_data()) ? make_a_copy : set_to_null;
   } else if (ref->msotype() == MetaspaceObj::AdapterHandlerEntryType) {
-    if (CDSConfig::is_dumping_adapters()) {
-      AdapterHandlerEntry* entry = (AdapterHandlerEntry*)ref->obj();
-      return AdapterHandlerLibrary::is_abstract_method_adapter(entry) ? set_to_null : make_a_copy;
-    } else {
-      return set_to_null;
-    }
+    return CDSConfig::is_dumping_adapters() ? make_a_copy : set_to_null;
   } else {
     if (ref->msotype() == MetaspaceObj::ClassType) {
       Klass* klass = (Klass*)ref->obj();

src/hotspot/share/oops/method.cpp

@@ -152,11 +152,17 @@ void Method::release_C_heap_structures() {
 }
 
 address Method::get_i2c_entry() {
+  if (is_abstract()) {
+    return SharedRuntime::throw_AbstractMethodError_entry();
+  }
   assert(adapter() != nullptr, "must have");
   return adapter()->get_i2c_entry();
 }
 
 address Method::get_c2i_entry() {
+  if (is_abstract()) {
+    return SharedRuntime::get_handle_wrong_method_abstract_stub();
+  }
   assert(adapter() != nullptr, "must have");
   return adapter()->get_c2i_entry();
 }
@@ -1165,9 +1171,9 @@ void Method::clear_code() {
   // this may be null if c2i adapters have not been made yet
   // Only should happen at allocate time.
   if (adapter() == nullptr) {
-    _from_compiled_entry    = nullptr;
+    _from_compiled_entry = nullptr;
   } else {
-    _from_compiled_entry    = adapter()->get_c2i_entry();
+    _from_compiled_entry = adapter()->get_c2i_entry();
   }
   OrderAccess::storestore();
   _from_interpreted_entry = _i2i_entry;
@@ -1196,7 +1202,7 @@ void Method::unlink_code() {
 void Method::unlink_method() {
   assert(CDSConfig::is_dumping_archive(), "sanity");
   _code = nullptr;
-  if (!CDSConfig::is_dumping_adapters() || AdapterHandlerLibrary::is_abstract_method_adapter(_adapter)) {
+  if (!CDSConfig::is_dumping_adapters()) {
     _adapter = nullptr;
   }
   _i2i_entry = nullptr;
@@ -1277,9 +1283,12 @@ void Method::link_method(const methodHandle& h_method, TRAPS) {
   // called from the vtable.  We need adapters on such methods that get loaded
   // later.  Ditto for mega-morphic itable calls.  If this proves to be a
   // problem we'll make these lazily later.
-  if (_adapter == nullptr) {
+  if (is_abstract()) {
+    h_method->_from_compiled_entry = SharedRuntime::get_handle_wrong_method_abstract_stub();
+  } else if (_adapter == nullptr) {
     (void) make_adapters(h_method, CHECK);
     assert(adapter()->is_linked(), "Adapter must have been linked");
+    h_method->_from_compiled_entry = adapter()->get_c2i_entry();
   }
 
   // ONLY USE the h_method now as make_adapter may have blocked
@@ -1300,6 +1309,7 @@ void Method::link_method(const methodHandle& h_method, TRAPS) {
 }
 
 address Method::make_adapters(const methodHandle& mh, TRAPS) {
+  assert(!mh->is_abstract(), "abstract methods do not have adapters");
   PerfTraceTime timer(ClassLoader::perf_method_adapters_time());
 
   // Adapters for compiled code are made eagerly here.  They are fairly
@@ -1318,7 +1328,6 @@ address Method::make_adapters(const methodHandle& mh, TRAPS) {
   }
 
   mh->set_adapter_entry(adapter);
-  mh->_from_compiled_entry = adapter->get_c2i_entry();
   return adapter->get_c2i_entry();
 }
 

src/hotspot/share/runtime/javaCalls.cpp

@@ -406,7 +406,7 @@ void JavaCalls::call_helper(JavaValue* result, const methodHandle& method, JavaC
             address verified_entry_point = (address) HotSpotJVMCI::InstalledCode::entryPoint(nullptr, alternative_target());
             if (verified_entry_point != nullptr) {
               thread->set_jvmci_alternate_call_target(verified_entry_point);
-              entry_point = method->adapter()->get_i2c_entry();
+              entry_point = method->get_i2c_entry();
             }
           }
 #endif

src/hotspot/share/runtime/sharedRuntime.cpp

@@ -2510,7 +2510,6 @@ static void print_table_statistics() {
 
 // ---------------------------------------------------------------------------
 // Implementation of AdapterHandlerLibrary
-AdapterHandlerEntry* AdapterHandlerLibrary::_abstract_method_handler = nullptr;
 AdapterHandlerEntry* AdapterHandlerLibrary::_no_arg_handler = nullptr;
 AdapterHandlerEntry* AdapterHandlerLibrary::_int_arg_handler = nullptr;
 AdapterHandlerEntry* AdapterHandlerLibrary::_obj_arg_handler = nullptr;
@@ -2546,28 +2545,11 @@ static void post_adapter_creation(const AdapterBlob* new_adapter,
   }
 }
 
-void AdapterHandlerLibrary::create_abstract_method_handler() {
-  assert_lock_strong(AdapterHandlerLibrary_lock);
-  // Create a special handler for abstract methods.  Abstract methods
-  // are never compiled so an i2c entry is somewhat meaningless, but
-  // throw AbstractMethodError just in case.
-  // Pass wrong_method_abstract for the c2i transitions to return
-  // AbstractMethodError for invalid invocations.
-  address wrong_method_abstract = SharedRuntime::get_handle_wrong_method_abstract_stub();
-  _abstract_method_handler = AdapterHandlerLibrary::new_entry(AdapterFingerPrint::allocate(0, nullptr));
-  _abstract_method_handler->set_entry_points(SharedRuntime::throw_AbstractMethodError_entry(),
-                                             wrong_method_abstract,
-                                             wrong_method_abstract,
-                                             nullptr);
-}
-
 void AdapterHandlerLibrary::initialize() {
   {
     ResourceMark rm;
-    MutexLocker mu(AdapterHandlerLibrary_lock);
     _adapter_handler_table = new (mtCode) AdapterHandlerTable();
     _buffer = BufferBlob::create("adapters", AdapterHandlerLibrary_size);
-    create_abstract_method_handler();
   }
 
 #if INCLUDE_CDS
@@ -2627,9 +2609,6 @@ AdapterHandlerEntry* AdapterHandlerLibrary::new_entry(AdapterFingerPrint* finger
 }
 
 AdapterHandlerEntry* AdapterHandlerLibrary::get_simple_adapter(const methodHandle& method) {
-  if (method->is_abstract()) {
-    return _abstract_method_handler;
-  }
   int total_args_passed = method->size_of_parameters(); // All args on stack
   if (total_args_passed == 0) {
     return _no_arg_handler;
@@ -2727,6 +2706,7 @@ void AdapterHandlerLibrary::verify_adapter_sharing(int total_args_passed, BasicT
 #endif /* ASSERT*/
 
 AdapterHandlerEntry* AdapterHandlerLibrary::get_adapter(const methodHandle& method) {
+  assert(!method->is_abstract(), "abstract methods do not have adapters");
   // Use customized signature handler.  Need to lock around updates to
   // the _adapter_handler_table (it is not safe for concurrent readers
   // and a single writer: this could be fixed if it becomes a
@@ -3497,13 +3477,6 @@ void AdapterHandlerLibrary::print_statistics() {
 
 #endif /* PRODUCT */
 
-bool AdapterHandlerLibrary::is_abstract_method_adapter(AdapterHandlerEntry* entry) {
-  if (entry == _abstract_method_handler) {
-    return true;
-  }
-  return false;
-}
-
 JRT_LEAF(void, SharedRuntime::enable_stack_reserved_zone(JavaThread* current))
   assert(current == JavaThread::current(), "pre-condition");
   StackOverflow* overflow_state = current->stack_overflow_state();

src/hotspot/share/runtime/sharedRuntime.hpp

@@ -783,7 +783,6 @@ class AdapterHandlerLibrary: public AllStatic {
   friend class SharedRuntime;
  private:
   static BufferBlob* _buffer; // the temporary code buffer in CodeCache
-  static AdapterHandlerEntry* _abstract_method_handler;
   static AdapterHandlerEntry* _no_arg_handler;
   static AdapterHandlerEntry* _int_arg_handler;
   static AdapterHandlerEntry* _obj_arg_handler;
@@ -801,7 +800,6 @@ class AdapterHandlerLibrary: public AllStatic {
                                              int total_args_passed,
                                              BasicType* sig_bt,
                                              bool is_transient = false);
-  static void create_abstract_method_handler();
   static void lookup_simple_adapters() NOT_CDS_RETURN;
 #ifndef PRODUCT
   static void print_adapter_handler_info(outputStream* st, AdapterHandlerEntry* handler, AdapterBlob* adapter_blob);
@@ -831,8 +829,6 @@ class AdapterHandlerLibrary: public AllStatic {
   static void print_statistics();
 #endif // PRODUCT
 
-  static bool is_abstract_method_adapter(AdapterHandlerEntry* adapter);
-
   static AdapterBlob* link_aot_adapter_handler(AdapterHandlerEntry* handler) NOT_CDS_RETURN_(nullptr);
   static void dump_aot_adapter_table() NOT_CDS_RETURN;
   static void serialize_shared_table_header(SerializeClosure* soc) NOT_CDS_RETURN;