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https://github.com/openjdk/jdk.git
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92eb334c91
Fixed an issue in class unloading to delay walk until class loader's aliveness is determined of modularity lists to remove dead modules Reviewed-by: coleenp, dholmes, sspitsyn, zgu
2929 lines
121 KiB
C++
2929 lines
121 KiB
C++
/*
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* Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*
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*/
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#include "precompiled.hpp"
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#include "classfile/classFileParser.hpp"
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#include "classfile/classFileStream.hpp"
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#include "classfile/classLoader.hpp"
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#include "classfile/classLoaderData.inline.hpp"
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#include "classfile/classLoaderExt.hpp"
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#include "classfile/dictionary.hpp"
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#include "classfile/javaClasses.inline.hpp"
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#include "classfile/klassFactory.hpp"
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#include "classfile/loaderConstraints.hpp"
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#include "classfile/packageEntry.hpp"
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#include "classfile/placeholders.hpp"
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#include "classfile/resolutionErrors.hpp"
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#include "classfile/stringTable.hpp"
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#include "classfile/systemDictionary.hpp"
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#include "classfile/vmSymbols.hpp"
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#include "code/codeCache.hpp"
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#include "compiler/compileBroker.hpp"
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#include "gc/shared/gcLocker.hpp"
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#include "interpreter/bytecodeStream.hpp"
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#include "interpreter/interpreter.hpp"
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#include "memory/filemap.hpp"
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#include "memory/oopFactory.hpp"
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#include "memory/resourceArea.hpp"
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#include "oops/instanceKlass.hpp"
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#include "oops/instanceRefKlass.hpp"
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#include "oops/klass.inline.hpp"
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#include "oops/methodData.hpp"
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#include "oops/objArrayKlass.hpp"
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#include "oops/objArrayOop.inline.hpp"
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#include "oops/oop.inline.hpp"
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#include "oops/symbol.hpp"
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#include "oops/typeArrayKlass.hpp"
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#include "prims/jvmtiEnvBase.hpp"
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#include "prims/methodHandles.hpp"
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#include "runtime/arguments.hpp"
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#include "runtime/biasedLocking.hpp"
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#include "runtime/fieldType.hpp"
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#include "runtime/handles.inline.hpp"
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#include "runtime/java.hpp"
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#include "runtime/javaCalls.hpp"
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#include "runtime/mutexLocker.hpp"
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#include "runtime/orderAccess.inline.hpp"
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#include "runtime/signature.hpp"
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#include "services/classLoadingService.hpp"
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#include "services/threadService.hpp"
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#include "trace/traceMacros.hpp"
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#include "utilities/macros.hpp"
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#include "utilities/stringUtils.hpp"
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#include "utilities/ticks.hpp"
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#if INCLUDE_CDS
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#include "classfile/sharedClassUtil.hpp"
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#include "classfile/systemDictionaryShared.hpp"
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#endif
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#if INCLUDE_JVMCI
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#include "jvmci/jvmciRuntime.hpp"
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#endif
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#if INCLUDE_TRACE
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#include "trace/tracing.hpp"
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#endif
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Dictionary* SystemDictionary::_dictionary = NULL;
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PlaceholderTable* SystemDictionary::_placeholders = NULL;
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Dictionary* SystemDictionary::_shared_dictionary = NULL;
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LoaderConstraintTable* SystemDictionary::_loader_constraints = NULL;
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ResolutionErrorTable* SystemDictionary::_resolution_errors = NULL;
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SymbolPropertyTable* SystemDictionary::_invoke_method_table = NULL;
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int SystemDictionary::_number_of_modifications = 0;
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int SystemDictionary::_sdgeneration = 0;
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const int SystemDictionary::_primelist[_prime_array_size] = {1009,2017,4049,5051,10103,
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20201,40423,99991};
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oop SystemDictionary::_system_loader_lock_obj = NULL;
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InstanceKlass* SystemDictionary::_well_known_klasses[SystemDictionary::WKID_LIMIT]
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= { NULL /*, NULL...*/ };
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InstanceKlass* SystemDictionary::_box_klasses[T_VOID+1] = { NULL /*, NULL...*/ };
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oop SystemDictionary::_java_system_loader = NULL;
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bool SystemDictionary::_has_loadClassInternal = false;
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bool SystemDictionary::_has_checkPackageAccess = false;
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// lazily initialized klass variables
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InstanceKlass* volatile SystemDictionary::_abstract_ownable_synchronizer_klass = NULL;
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// ----------------------------------------------------------------------------
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// Java-level SystemLoader
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oop SystemDictionary::java_system_loader() {
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return _java_system_loader;
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}
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void SystemDictionary::compute_java_system_loader(TRAPS) {
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KlassHandle system_klass(THREAD, WK_KLASS(ClassLoader_klass));
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JavaValue result(T_OBJECT);
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JavaCalls::call_static(&result,
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KlassHandle(THREAD, WK_KLASS(ClassLoader_klass)),
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vmSymbols::getSystemClassLoader_name(),
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vmSymbols::void_classloader_signature(),
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CHECK);
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_java_system_loader = (oop)result.get_jobject();
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CDS_ONLY(SystemDictionaryShared::initialize(CHECK);)
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}
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ClassLoaderData* SystemDictionary::register_loader(Handle class_loader, TRAPS) {
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if (class_loader() == NULL) return ClassLoaderData::the_null_class_loader_data();
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return ClassLoaderDataGraph::find_or_create(class_loader, THREAD);
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}
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// ----------------------------------------------------------------------------
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// debugging
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#ifdef ASSERT
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// return true if class_name contains no '.' (internal format is '/')
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bool SystemDictionary::is_internal_format(Symbol* class_name) {
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if (class_name != NULL) {
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ResourceMark rm;
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char* name = class_name->as_C_string();
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return strchr(name, '.') == NULL;
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} else {
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return true;
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}
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}
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#endif
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// ----------------------------------------------------------------------------
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// Parallel class loading check
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bool SystemDictionary::is_parallelCapable(Handle class_loader) {
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if (UnsyncloadClass || class_loader.is_null()) return true;
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if (AlwaysLockClassLoader) return false;
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return java_lang_ClassLoader::parallelCapable(class_loader());
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}
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// ----------------------------------------------------------------------------
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// ParallelDefineClass flag does not apply to bootclass loader
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bool SystemDictionary::is_parallelDefine(Handle class_loader) {
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if (class_loader.is_null()) return false;
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if (AllowParallelDefineClass && java_lang_ClassLoader::parallelCapable(class_loader())) {
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return true;
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}
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return false;
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}
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// Returns true if the passed class loader is the builtin application class loader
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// or a custom system class loader. A customer system class loader can be
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// specified via -Djava.system.class.loader.
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bool SystemDictionary::is_system_class_loader(Handle class_loader) {
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if (class_loader.is_null()) {
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return false;
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}
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return (class_loader->klass() == SystemDictionary::jdk_internal_loader_ClassLoaders_AppClassLoader_klass() ||
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class_loader() == _java_system_loader);
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}
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// Returns true if the passed class loader is the platform class loader.
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bool SystemDictionary::is_platform_class_loader(Handle class_loader) {
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if (class_loader.is_null()) {
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return false;
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}
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return (class_loader->klass() == SystemDictionary::jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass());
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}
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// ----------------------------------------------------------------------------
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// Resolving of classes
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// Forwards to resolve_or_null
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Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS) {
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Klass* klass = resolve_or_null(class_name, class_loader, protection_domain, THREAD);
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if (HAS_PENDING_EXCEPTION || klass == NULL) {
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KlassHandle k_h(THREAD, klass);
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// can return a null klass
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klass = handle_resolution_exception(class_name, throw_error, k_h, THREAD);
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}
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return klass;
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}
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Klass* SystemDictionary::handle_resolution_exception(Symbol* class_name,
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bool throw_error,
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KlassHandle klass_h, TRAPS) {
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if (HAS_PENDING_EXCEPTION) {
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// If we have a pending exception we forward it to the caller, unless throw_error is true,
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// in which case we have to check whether the pending exception is a ClassNotFoundException,
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// and if so convert it to a NoClassDefFoundError
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// And chain the original ClassNotFoundException
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if (throw_error && PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass())) {
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ResourceMark rm(THREAD);
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assert(klass_h() == NULL, "Should not have result with exception pending");
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Handle e(THREAD, PENDING_EXCEPTION);
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CLEAR_PENDING_EXCEPTION;
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THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string(), e);
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} else {
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return NULL;
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}
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}
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// Class not found, throw appropriate error or exception depending on value of throw_error
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if (klass_h() == NULL) {
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ResourceMark rm(THREAD);
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if (throw_error) {
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THROW_MSG_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string());
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} else {
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THROW_MSG_NULL(vmSymbols::java_lang_ClassNotFoundException(), class_name->as_C_string());
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}
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}
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return (Klass*)klass_h();
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}
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Klass* SystemDictionary::resolve_or_fail(Symbol* class_name,
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bool throw_error, TRAPS)
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{
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return resolve_or_fail(class_name, Handle(), Handle(), throw_error, THREAD);
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}
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// Forwards to resolve_instance_class_or_null
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Klass* SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS) {
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assert(THREAD->can_call_java(),
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"can not load classes with compiler thread: class=%s, classloader=%s",
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class_name->as_C_string(),
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class_loader.is_null() ? "null" : class_loader->klass()->name()->as_C_string());
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if (FieldType::is_array(class_name)) {
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return resolve_array_class_or_null(class_name, class_loader, protection_domain, THREAD);
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} else if (FieldType::is_obj(class_name)) {
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ResourceMark rm(THREAD);
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// Ignore wrapping L and ;.
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TempNewSymbol name = SymbolTable::new_symbol(class_name->as_C_string() + 1,
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class_name->utf8_length() - 2, CHECK_NULL);
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return resolve_instance_class_or_null(name, class_loader, protection_domain, THREAD);
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} else {
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return resolve_instance_class_or_null(class_name, class_loader, protection_domain, THREAD);
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}
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}
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Klass* SystemDictionary::resolve_or_null(Symbol* class_name, TRAPS) {
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return resolve_or_null(class_name, Handle(), Handle(), THREAD);
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}
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// Forwards to resolve_instance_class_or_null
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Klass* SystemDictionary::resolve_array_class_or_null(Symbol* class_name,
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Handle class_loader,
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Handle protection_domain,
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TRAPS) {
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assert(FieldType::is_array(class_name), "must be array");
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Klass* k = NULL;
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FieldArrayInfo fd;
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// dimension and object_key in FieldArrayInfo are assigned as a side-effect
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// of this call
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BasicType t = FieldType::get_array_info(class_name, fd, CHECK_NULL);
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if (t == T_OBJECT) {
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// naked oop "k" is OK here -- we assign back into it
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k = SystemDictionary::resolve_instance_class_or_null(fd.object_key(),
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class_loader,
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protection_domain,
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CHECK_NULL);
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if (k != NULL) {
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k = k->array_klass(fd.dimension(), CHECK_NULL);
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}
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} else {
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k = Universe::typeArrayKlassObj(t);
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k = TypeArrayKlass::cast(k)->array_klass(fd.dimension(), CHECK_NULL);
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}
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return k;
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}
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// Must be called for any super-class or super-interface resolution
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// during class definition to allow class circularity checking
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// super-interface callers:
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// parse_interfaces - for defineClass & jvmtiRedefineClasses
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// super-class callers:
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// ClassFileParser - for defineClass & jvmtiRedefineClasses
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// load_shared_class - while loading a class from shared archive
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// resolve_instance_class_or_null:
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// via: handle_parallel_super_load
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// when resolving a class that has an existing placeholder with
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// a saved superclass [i.e. a defineClass is currently in progress]
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// if another thread is trying to resolve the class, it must do
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// super-class checks on its own thread to catch class circularity
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// This last call is critical in class circularity checking for cases
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// where classloading is delegated to different threads and the
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// classloader lock is released.
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// Take the case: Base->Super->Base
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// 1. If thread T1 tries to do a defineClass of class Base
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// resolve_super_or_fail creates placeholder: T1, Base (super Super)
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// 2. resolve_instance_class_or_null does not find SD or placeholder for Super
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// so it tries to load Super
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// 3. If we load the class internally, or user classloader uses same thread
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// loadClassFromxxx or defineClass via parseClassFile Super ...
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// 3.1 resolve_super_or_fail creates placeholder: T1, Super (super Base)
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// 3.3 resolve_instance_class_or_null Base, finds placeholder for Base
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// 3.4 calls resolve_super_or_fail Base
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// 3.5 finds T1,Base -> throws class circularity
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//OR 4. If T2 tries to resolve Super via defineClass Super ...
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// 4.1 resolve_super_or_fail creates placeholder: T2, Super (super Base)
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// 4.2 resolve_instance_class_or_null Base, finds placeholder for Base (super Super)
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// 4.3 calls resolve_super_or_fail Super in parallel on own thread T2
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// 4.4 finds T2, Super -> throws class circularity
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// Must be called, even if superclass is null, since this is
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// where the placeholder entry is created which claims this
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// thread is loading this class/classloader.
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Klass* SystemDictionary::resolve_super_or_fail(Symbol* child_name,
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Symbol* class_name,
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Handle class_loader,
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Handle protection_domain,
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bool is_superclass,
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TRAPS) {
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#if INCLUDE_CDS
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if (DumpSharedSpaces) {
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// Special processing for CDS dump time.
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Klass* k = SystemDictionaryShared::dump_time_resolve_super_or_fail(child_name,
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class_name, class_loader, protection_domain, is_superclass, CHECK_NULL);
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if (k) {
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return k;
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}
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}
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#endif // INCLUDE_CDS
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// Double-check, if child class is already loaded, just return super-class,interface
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// Don't add a placedholder if already loaded, i.e. already in system dictionary
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// Make sure there's a placeholder for the *child* before resolving.
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// Used as a claim that this thread is currently loading superclass/classloader
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// Used here for ClassCircularity checks and also for heap verification
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// (every InstanceKlass in the heap needs to be in the system dictionary
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// or have a placeholder).
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// Must check ClassCircularity before checking if super class is already loaded
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//
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// We might not already have a placeholder if this child_name was
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// first seen via resolve_from_stream (jni_DefineClass or JVM_DefineClass);
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// the name of the class might not be known until the stream is actually
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// parsed.
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// Bugs 4643874, 4715493
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// compute_hash can have a safepoint
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ClassLoaderData* loader_data = class_loader_data(class_loader);
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unsigned int d_hash = dictionary()->compute_hash(child_name, loader_data);
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int d_index = dictionary()->hash_to_index(d_hash);
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unsigned int p_hash = placeholders()->compute_hash(child_name, loader_data);
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int p_index = placeholders()->hash_to_index(p_hash);
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// can't throw error holding a lock
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bool child_already_loaded = false;
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bool throw_circularity_error = false;
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{
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MutexLocker mu(SystemDictionary_lock, THREAD);
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Klass* childk = find_class(d_index, d_hash, child_name, loader_data);
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Klass* quicksuperk;
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// to support // loading: if child done loading, just return superclass
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// if class_name, & class_loader don't match:
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// if initial define, SD update will give LinkageError
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// if redefine: compare_class_versions will give HIERARCHY_CHANGED
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// so we don't throw an exception here.
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// see: nsk redefclass014 & java.lang.instrument Instrument032
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if ((childk != NULL ) && (is_superclass) &&
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((quicksuperk = childk->super()) != NULL) &&
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((quicksuperk->name() == class_name) &&
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(quicksuperk->class_loader() == class_loader()))) {
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return quicksuperk;
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} else {
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PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, loader_data);
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if (probe && probe->check_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER)) {
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throw_circularity_error = true;
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}
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}
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if (!throw_circularity_error) {
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PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, class_name, THREAD);
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}
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}
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if (throw_circularity_error) {
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ResourceMark rm(THREAD);
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THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), child_name->as_C_string());
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}
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// java.lang.Object should have been found above
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assert(class_name != NULL, "null super class for resolving");
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// Resolve the super class or interface, check results on return
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Klass* superk = SystemDictionary::resolve_or_null(class_name,
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class_loader,
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protection_domain,
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THREAD);
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KlassHandle superk_h(THREAD, superk);
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// Clean up of placeholders moved so that each classloadAction registrar self-cleans up
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// It is no longer necessary to keep the placeholder table alive until update_dictionary
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// or error. GC used to walk the placeholder table as strong roots.
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// The instanceKlass is kept alive because the class loader is on the stack,
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// which keeps the loader_data alive, as well as all instanceKlasses in
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// the loader_data. parseClassFile adds the instanceKlass to loader_data.
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{
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MutexLocker mu(SystemDictionary_lock, THREAD);
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placeholders()->find_and_remove(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, THREAD);
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SystemDictionary_lock->notify_all();
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}
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if (HAS_PENDING_EXCEPTION || superk_h() == NULL) {
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// can null superk
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superk_h = KlassHandle(THREAD, handle_resolution_exception(class_name, true, superk_h, THREAD));
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}
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return superk_h();
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}
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void SystemDictionary::validate_protection_domain(instanceKlassHandle klass,
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Handle class_loader,
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Handle protection_domain,
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TRAPS) {
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if(!has_checkPackageAccess()) return;
|
|
|
|
// Now we have to call back to java to check if the initating class has access
|
|
JavaValue result(T_VOID);
|
|
if (log_is_enabled(Debug, protectiondomain)) {
|
|
ResourceMark rm;
|
|
// Print out trace information
|
|
outputStream* log = Log(protectiondomain)::debug_stream();
|
|
log->print_cr("Checking package access");
|
|
log->print("class loader: "); class_loader()->print_value_on(log);
|
|
log->print(" protection domain: "); protection_domain()->print_value_on(log);
|
|
log->print(" loading: "); klass()->print_value_on(log);
|
|
log->cr();
|
|
}
|
|
|
|
KlassHandle system_loader(THREAD, SystemDictionary::ClassLoader_klass());
|
|
JavaCalls::call_special(&result,
|
|
class_loader,
|
|
system_loader,
|
|
vmSymbols::checkPackageAccess_name(),
|
|
vmSymbols::class_protectiondomain_signature(),
|
|
Handle(THREAD, klass->java_mirror()),
|
|
protection_domain,
|
|
THREAD);
|
|
|
|
if (HAS_PENDING_EXCEPTION) {
|
|
log_debug(protectiondomain)("DENIED !!!!!!!!!!!!!!!!!!!!!");
|
|
} else {
|
|
log_debug(protectiondomain)("granted");
|
|
}
|
|
|
|
if (HAS_PENDING_EXCEPTION) return;
|
|
|
|
// If no exception has been thrown, we have validated the protection domain
|
|
// Insert the protection domain of the initiating class into the set.
|
|
{
|
|
// We recalculate the entry here -- we've called out to java since
|
|
// the last time it was calculated.
|
|
ClassLoaderData* loader_data = class_loader_data(class_loader);
|
|
|
|
Symbol* kn = klass->name();
|
|
unsigned int d_hash = dictionary()->compute_hash(kn, loader_data);
|
|
int d_index = dictionary()->hash_to_index(d_hash);
|
|
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
{
|
|
// Note that we have an entry, and entries can be deleted only during GC,
|
|
// so we cannot allow GC to occur while we're holding this entry.
|
|
|
|
// We're using a NoSafepointVerifier to catch any place where we
|
|
// might potentially do a GC at all.
|
|
// Dictionary::do_unloading() asserts that classes in SD are only
|
|
// unloaded at a safepoint. Anonymous classes are not in SD.
|
|
NoSafepointVerifier nosafepoint;
|
|
dictionary()->add_protection_domain(d_index, d_hash, klass, loader_data,
|
|
protection_domain, THREAD);
|
|
}
|
|
}
|
|
}
|
|
|
|
// We only get here if this thread finds that another thread
|
|
// has already claimed the placeholder token for the current operation,
|
|
// but that other thread either never owned or gave up the
|
|
// object lock
|
|
// Waits on SystemDictionary_lock to indicate placeholder table updated
|
|
// On return, caller must recheck placeholder table state
|
|
//
|
|
// We only get here if
|
|
// 1) custom classLoader, i.e. not bootstrap classloader
|
|
// 2) UnsyncloadClass not set
|
|
// 3) custom classLoader has broken the class loader objectLock
|
|
// so another thread got here in parallel
|
|
//
|
|
// lockObject must be held.
|
|
// Complicated dance due to lock ordering:
|
|
// Must first release the classloader object lock to
|
|
// allow initial definer to complete the class definition
|
|
// and to avoid deadlock
|
|
// Reclaim classloader lock object with same original recursion count
|
|
// Must release SystemDictionary_lock after notify, since
|
|
// class loader lock must be claimed before SystemDictionary_lock
|
|
// to prevent deadlocks
|
|
//
|
|
// The notify allows applications that did an untimed wait() on
|
|
// the classloader object lock to not hang.
|
|
void SystemDictionary::double_lock_wait(Handle lockObject, TRAPS) {
|
|
assert_lock_strong(SystemDictionary_lock);
|
|
|
|
bool calledholdinglock
|
|
= ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD, lockObject);
|
|
assert(calledholdinglock,"must hold lock for notify");
|
|
assert((!(lockObject() == _system_loader_lock_obj) && !is_parallelCapable(lockObject)), "unexpected double_lock_wait");
|
|
ObjectSynchronizer::notifyall(lockObject, THREAD);
|
|
intptr_t recursions = ObjectSynchronizer::complete_exit(lockObject, THREAD);
|
|
SystemDictionary_lock->wait();
|
|
SystemDictionary_lock->unlock();
|
|
ObjectSynchronizer::reenter(lockObject, recursions, THREAD);
|
|
SystemDictionary_lock->lock();
|
|
}
|
|
|
|
// If the class in is in the placeholder table, class loading is in progress
|
|
// For cases where the application changes threads to load classes, it
|
|
// is critical to ClassCircularity detection that we try loading
|
|
// the superclass on the same thread internally, so we do parallel
|
|
// super class loading here.
|
|
// This also is critical in cases where the original thread gets stalled
|
|
// even in non-circularity situations.
|
|
// Note: must call resolve_super_or_fail even if null super -
|
|
// to force placeholder entry creation for this class for circularity detection
|
|
// Caller must check for pending exception
|
|
// Returns non-null Klass* if other thread has completed load
|
|
// and we are done,
|
|
// If return null Klass* and no pending exception, the caller must load the class
|
|
instanceKlassHandle SystemDictionary::handle_parallel_super_load(
|
|
Symbol* name, Symbol* superclassname, Handle class_loader,
|
|
Handle protection_domain, Handle lockObject, TRAPS) {
|
|
|
|
instanceKlassHandle nh = instanceKlassHandle(); // null Handle
|
|
ClassLoaderData* loader_data = class_loader_data(class_loader);
|
|
unsigned int d_hash = dictionary()->compute_hash(name, loader_data);
|
|
int d_index = dictionary()->hash_to_index(d_hash);
|
|
unsigned int p_hash = placeholders()->compute_hash(name, loader_data);
|
|
int p_index = placeholders()->hash_to_index(p_hash);
|
|
|
|
// superk is not used, resolve_super called for circularity check only
|
|
// This code is reached in two situations. One if this thread
|
|
// is loading the same class twice (e.g. ClassCircularity, or
|
|
// java.lang.instrument).
|
|
// The second is if another thread started the resolve_super first
|
|
// and has not yet finished.
|
|
// In both cases the original caller will clean up the placeholder
|
|
// entry on error.
|
|
Klass* superk = SystemDictionary::resolve_super_or_fail(name,
|
|
superclassname,
|
|
class_loader,
|
|
protection_domain,
|
|
true,
|
|
CHECK_(nh));
|
|
|
|
// parallelCapable class loaders do NOT wait for parallel superclass loads to complete
|
|
// Serial class loaders and bootstrap classloader do wait for superclass loads
|
|
if (!class_loader.is_null() && is_parallelCapable(class_loader)) {
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
// Check if classloading completed while we were loading superclass or waiting
|
|
Klass* check = find_class(d_index, d_hash, name, loader_data);
|
|
if (check != NULL) {
|
|
// Klass is already loaded, so just return it
|
|
return(instanceKlassHandle(THREAD, check));
|
|
} else {
|
|
return nh;
|
|
}
|
|
}
|
|
|
|
// must loop to both handle other placeholder updates
|
|
// and spurious notifications
|
|
bool super_load_in_progress = true;
|
|
PlaceholderEntry* placeholder;
|
|
while (super_load_in_progress) {
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
// Check if classloading completed while we were loading superclass or waiting
|
|
Klass* check = find_class(d_index, d_hash, name, loader_data);
|
|
if (check != NULL) {
|
|
// Klass is already loaded, so just return it
|
|
return(instanceKlassHandle(THREAD, check));
|
|
} else {
|
|
placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
|
|
if (placeholder && placeholder->super_load_in_progress() ){
|
|
// Before UnsyncloadClass:
|
|
// We only get here if the application has released the
|
|
// classloader lock when another thread was in the middle of loading a
|
|
// superclass/superinterface for this class, and now
|
|
// this thread is also trying to load this class.
|
|
// To minimize surprises, the first thread that started to
|
|
// load a class should be the one to complete the loading
|
|
// with the classfile it initially expected.
|
|
// This logic has the current thread wait once it has done
|
|
// all the superclass/superinterface loading it can, until
|
|
// the original thread completes the class loading or fails
|
|
// If it completes we will use the resulting InstanceKlass
|
|
// which we will find below in the systemDictionary.
|
|
// We also get here for parallel bootstrap classloader
|
|
if (class_loader.is_null()) {
|
|
SystemDictionary_lock->wait();
|
|
} else {
|
|
double_lock_wait(lockObject, THREAD);
|
|
}
|
|
} else {
|
|
// If not in SD and not in PH, other thread's load must have failed
|
|
super_load_in_progress = false;
|
|
}
|
|
}
|
|
}
|
|
return (nh);
|
|
}
|
|
|
|
// utility function for class load event
|
|
static void post_class_load_event(const Ticks& start_time,
|
|
instanceKlassHandle k,
|
|
Handle initiating_loader) {
|
|
#if INCLUDE_TRACE
|
|
EventClassLoad event(UNTIMED);
|
|
if (event.should_commit()) {
|
|
event.set_starttime(start_time);
|
|
event.set_loadedClass(k());
|
|
oop defining_class_loader = k->class_loader();
|
|
event.set_definingClassLoader(defining_class_loader != NULL ?
|
|
defining_class_loader->klass() : (Klass*)NULL);
|
|
oop class_loader = initiating_loader.is_null() ? (oop)NULL : initiating_loader();
|
|
event.set_initiatingClassLoader(class_loader != NULL ?
|
|
class_loader->klass() : (Klass*)NULL);
|
|
event.commit();
|
|
}
|
|
#endif // INCLUDE_TRACE
|
|
}
|
|
|
|
Klass* SystemDictionary::resolve_instance_class_or_null(Symbol* name,
|
|
Handle class_loader,
|
|
Handle protection_domain,
|
|
TRAPS) {
|
|
assert(name != NULL && !FieldType::is_array(name) &&
|
|
!FieldType::is_obj(name), "invalid class name");
|
|
|
|
Ticks class_load_start_time = Ticks::now();
|
|
|
|
// Fix for 4474172; see evaluation for more details
|
|
class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
|
|
ClassLoaderData *loader_data = register_loader(class_loader, CHECK_NULL);
|
|
|
|
// Do lookup to see if class already exist and the protection domain
|
|
// has the right access
|
|
// This call uses find which checks protection domain already matches
|
|
// All subsequent calls use find_class, and set has_loaded_class so that
|
|
// before we return a result we call out to java to check for valid protection domain
|
|
// to allow returning the Klass* and add it to the pd_set if it is valid
|
|
unsigned int d_hash = dictionary()->compute_hash(name, loader_data);
|
|
int d_index = dictionary()->hash_to_index(d_hash);
|
|
Klass* probe = dictionary()->find(d_index, d_hash, name, loader_data,
|
|
protection_domain, THREAD);
|
|
if (probe != NULL) return probe;
|
|
|
|
|
|
// Non-bootstrap class loaders will call out to class loader and
|
|
// define via jvm/jni_DefineClass which will acquire the
|
|
// class loader object lock to protect against multiple threads
|
|
// defining the class in parallel by accident.
|
|
// This lock must be acquired here so the waiter will find
|
|
// any successful result in the SystemDictionary and not attempt
|
|
// the define
|
|
// ParallelCapable Classloaders and the bootstrap classloader,
|
|
// or all classloaders with UnsyncloadClass do not acquire lock here
|
|
bool DoObjectLock = true;
|
|
if (is_parallelCapable(class_loader)) {
|
|
DoObjectLock = false;
|
|
}
|
|
|
|
unsigned int p_hash = placeholders()->compute_hash(name, loader_data);
|
|
int p_index = placeholders()->hash_to_index(p_hash);
|
|
|
|
// Class is not in SystemDictionary so we have to do loading.
|
|
// Make sure we are synchronized on the class loader before we proceed
|
|
Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
|
|
check_loader_lock_contention(lockObject, THREAD);
|
|
ObjectLocker ol(lockObject, THREAD, DoObjectLock);
|
|
|
|
// Check again (after locking) if class already exist in SystemDictionary
|
|
bool class_has_been_loaded = false;
|
|
bool super_load_in_progress = false;
|
|
bool havesupername = false;
|
|
instanceKlassHandle k;
|
|
PlaceholderEntry* placeholder;
|
|
Symbol* superclassname = NULL;
|
|
|
|
{
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
Klass* check = find_class(d_index, d_hash, name, loader_data);
|
|
if (check != NULL) {
|
|
// Klass is already loaded, so just return it
|
|
class_has_been_loaded = true;
|
|
k = instanceKlassHandle(THREAD, check);
|
|
} else {
|
|
placeholder = placeholders()->get_entry(p_index, p_hash, name, loader_data);
|
|
if (placeholder && placeholder->super_load_in_progress()) {
|
|
super_load_in_progress = true;
|
|
if (placeholder->havesupername() == true) {
|
|
superclassname = placeholder->supername();
|
|
havesupername = true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// If the class is in the placeholder table, class loading is in progress
|
|
if (super_load_in_progress && havesupername==true) {
|
|
k = SystemDictionary::handle_parallel_super_load(name, superclassname,
|
|
class_loader, protection_domain, lockObject, THREAD);
|
|
if (HAS_PENDING_EXCEPTION) {
|
|
return NULL;
|
|
}
|
|
if (!k.is_null()) {
|
|
class_has_been_loaded = true;
|
|
}
|
|
}
|
|
|
|
bool throw_circularity_error = false;
|
|
if (!class_has_been_loaded) {
|
|
bool load_instance_added = false;
|
|
|
|
// add placeholder entry to record loading instance class
|
|
// Five cases:
|
|
// All cases need to prevent modifying bootclasssearchpath
|
|
// in parallel with a classload of same classname
|
|
// Redefineclasses uses existence of the placeholder for the duration
|
|
// of the class load to prevent concurrent redefinition of not completely
|
|
// defined classes.
|
|
// case 1. traditional classloaders that rely on the classloader object lock
|
|
// - no other need for LOAD_INSTANCE
|
|
// case 2. traditional classloaders that break the classloader object lock
|
|
// as a deadlock workaround. Detection of this case requires that
|
|
// this check is done while holding the classloader object lock,
|
|
// and that lock is still held when calling classloader's loadClass.
|
|
// For these classloaders, we ensure that the first requestor
|
|
// completes the load and other requestors wait for completion.
|
|
// case 3. UnsyncloadClass - don't use objectLocker
|
|
// With this flag, we allow parallel classloading of a
|
|
// class/classloader pair
|
|
// case4. Bootstrap classloader - don't own objectLocker
|
|
// This classloader supports parallelism at the classloader level,
|
|
// but only allows a single load of a class/classloader pair.
|
|
// No performance benefit and no deadlock issues.
|
|
// case 5. parallelCapable user level classloaders - without objectLocker
|
|
// Allow parallel classloading of a class/classloader pair
|
|
|
|
{
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
if (class_loader.is_null() || !is_parallelCapable(class_loader)) {
|
|
PlaceholderEntry* oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
|
|
if (oldprobe) {
|
|
// only need check_seen_thread once, not on each loop
|
|
// 6341374 java/lang/Instrument with -Xcomp
|
|
if (oldprobe->check_seen_thread(THREAD, PlaceholderTable::LOAD_INSTANCE)) {
|
|
throw_circularity_error = true;
|
|
} else {
|
|
// case 1: traditional: should never see load_in_progress.
|
|
while (!class_has_been_loaded && oldprobe && oldprobe->instance_load_in_progress()) {
|
|
|
|
// case 4: bootstrap classloader: prevent futile classloading,
|
|
// wait on first requestor
|
|
if (class_loader.is_null()) {
|
|
SystemDictionary_lock->wait();
|
|
} else {
|
|
// case 2: traditional with broken classloader lock. wait on first
|
|
// requestor.
|
|
double_lock_wait(lockObject, THREAD);
|
|
}
|
|
// Check if classloading completed while we were waiting
|
|
Klass* check = find_class(d_index, d_hash, name, loader_data);
|
|
if (check != NULL) {
|
|
// Klass is already loaded, so just return it
|
|
k = instanceKlassHandle(THREAD, check);
|
|
class_has_been_loaded = true;
|
|
}
|
|
// check if other thread failed to load and cleaned up
|
|
oldprobe = placeholders()->get_entry(p_index, p_hash, name, loader_data);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
// All cases: add LOAD_INSTANCE holding SystemDictionary_lock
|
|
// case 3: UnsyncloadClass || case 5: parallelCapable: allow competing threads to try
|
|
// LOAD_INSTANCE in parallel
|
|
|
|
if (!throw_circularity_error && !class_has_been_loaded) {
|
|
PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, NULL, THREAD);
|
|
load_instance_added = true;
|
|
// For class loaders that do not acquire the classloader object lock,
|
|
// if they did not catch another thread holding LOAD_INSTANCE,
|
|
// need a check analogous to the acquire ObjectLocker/find_class
|
|
// i.e. now that we hold the LOAD_INSTANCE token on loading this class/CL
|
|
// one final check if the load has already completed
|
|
// class loaders holding the ObjectLock shouldn't find the class here
|
|
Klass* check = find_class(d_index, d_hash, name, loader_data);
|
|
if (check != NULL) {
|
|
// Klass is already loaded, so return it after checking/adding protection domain
|
|
k = instanceKlassHandle(THREAD, check);
|
|
class_has_been_loaded = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
// must throw error outside of owning lock
|
|
if (throw_circularity_error) {
|
|
assert(!HAS_PENDING_EXCEPTION && load_instance_added == false,"circularity error cleanup");
|
|
ResourceMark rm(THREAD);
|
|
THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), name->as_C_string());
|
|
}
|
|
|
|
if (!class_has_been_loaded) {
|
|
|
|
// Do actual loading
|
|
k = load_instance_class(name, class_loader, THREAD);
|
|
|
|
// For UnsyncloadClass only
|
|
// If they got a linkageError, check if a parallel class load succeeded.
|
|
// If it did, then for bytecode resolution the specification requires
|
|
// that we return the same result we did for the other thread, i.e. the
|
|
// successfully loaded InstanceKlass
|
|
// Should not get here for classloaders that support parallelism
|
|
// with the new cleaner mechanism, even with AllowParallelDefineClass
|
|
// Bootstrap goes through here to allow for an extra guarantee check
|
|
if (UnsyncloadClass || (class_loader.is_null())) {
|
|
if (k.is_null() && HAS_PENDING_EXCEPTION
|
|
&& PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
Klass* check = find_class(d_index, d_hash, name, loader_data);
|
|
if (check != NULL) {
|
|
// Klass is already loaded, so just use it
|
|
k = instanceKlassHandle(THREAD, check);
|
|
CLEAR_PENDING_EXCEPTION;
|
|
guarantee((!class_loader.is_null()), "dup definition for bootstrap loader?");
|
|
}
|
|
}
|
|
}
|
|
|
|
// If everything was OK (no exceptions, no null return value), and
|
|
// class_loader is NOT the defining loader, do a little more bookkeeping.
|
|
if (!HAS_PENDING_EXCEPTION && !k.is_null() &&
|
|
k->class_loader() != class_loader()) {
|
|
|
|
check_constraints(d_index, d_hash, k, class_loader, false, THREAD);
|
|
|
|
// Need to check for a PENDING_EXCEPTION again; check_constraints
|
|
// can throw and doesn't use the CHECK macro.
|
|
if (!HAS_PENDING_EXCEPTION) {
|
|
{ // Grabbing the Compile_lock prevents systemDictionary updates
|
|
// during compilations.
|
|
MutexLocker mu(Compile_lock, THREAD);
|
|
update_dictionary(d_index, d_hash, p_index, p_hash,
|
|
k, class_loader, THREAD);
|
|
}
|
|
|
|
if (JvmtiExport::should_post_class_load()) {
|
|
Thread *thread = THREAD;
|
|
assert(thread->is_Java_thread(), "thread->is_Java_thread()");
|
|
JvmtiExport::post_class_load((JavaThread *) thread, k());
|
|
}
|
|
}
|
|
}
|
|
} // load_instance_class loop
|
|
|
|
if (load_instance_added == true) {
|
|
// clean up placeholder entries for LOAD_INSTANCE success or error
|
|
// This brackets the SystemDictionary updates for both defining
|
|
// and initiating loaders
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
placeholders()->find_and_remove(p_index, p_hash, name, loader_data, PlaceholderTable::LOAD_INSTANCE, THREAD);
|
|
SystemDictionary_lock->notify_all();
|
|
}
|
|
}
|
|
|
|
if (HAS_PENDING_EXCEPTION || k.is_null()) {
|
|
return NULL;
|
|
}
|
|
|
|
post_class_load_event(class_load_start_time, k, class_loader);
|
|
|
|
#ifdef ASSERT
|
|
{
|
|
ClassLoaderData* loader_data = k->class_loader_data();
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
Klass* kk = find_class(name, loader_data);
|
|
assert(kk == k(), "should be present in dictionary");
|
|
}
|
|
#endif
|
|
|
|
// return if the protection domain in NULL
|
|
if (protection_domain() == NULL) return k();
|
|
|
|
// Check the protection domain has the right access
|
|
{
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
// Note that we have an entry, and entries can be deleted only during GC,
|
|
// so we cannot allow GC to occur while we're holding this entry.
|
|
// We're using a NoSafepointVerifier to catch any place where we
|
|
// might potentially do a GC at all.
|
|
// Dictionary::do_unloading() asserts that classes in SD are only
|
|
// unloaded at a safepoint. Anonymous classes are not in SD.
|
|
NoSafepointVerifier nosafepoint;
|
|
if (dictionary()->is_valid_protection_domain(d_index, d_hash, name,
|
|
loader_data,
|
|
protection_domain)) {
|
|
return k();
|
|
}
|
|
}
|
|
|
|
// Verify protection domain. If it fails an exception is thrown
|
|
validate_protection_domain(k, class_loader, protection_domain, CHECK_NULL);
|
|
|
|
return k();
|
|
}
|
|
|
|
|
|
// This routine does not lock the system dictionary.
|
|
//
|
|
// Since readers don't hold a lock, we must make sure that system
|
|
// dictionary entries are only removed at a safepoint (when only one
|
|
// thread is running), and are added to in a safe way (all links must
|
|
// be updated in an MT-safe manner).
|
|
//
|
|
// Callers should be aware that an entry could be added just after
|
|
// _dictionary->bucket(index) is read here, so the caller will not see
|
|
// the new entry.
|
|
|
|
Klass* SystemDictionary::find(Symbol* class_name,
|
|
Handle class_loader,
|
|
Handle protection_domain,
|
|
TRAPS) {
|
|
|
|
// The result of this call should be consistent with the result
|
|
// of the call to resolve_instance_class_or_null().
|
|
// See evaluation 6790209 and 4474172 for more details.
|
|
class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
|
|
ClassLoaderData* loader_data = ClassLoaderData::class_loader_data_or_null(class_loader());
|
|
|
|
if (loader_data == NULL) {
|
|
// If the ClassLoaderData has not been setup,
|
|
// then the class loader has no entries in the dictionary.
|
|
return NULL;
|
|
}
|
|
|
|
unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data);
|
|
int d_index = dictionary()->hash_to_index(d_hash);
|
|
|
|
{
|
|
// Note that we have an entry, and entries can be deleted only during GC,
|
|
// so we cannot allow GC to occur while we're holding this entry.
|
|
// We're using a NoSafepointVerifier to catch any place where we
|
|
// might potentially do a GC at all.
|
|
// Dictionary::do_unloading() asserts that classes in SD are only
|
|
// unloaded at a safepoint. Anonymous classes are not in SD.
|
|
NoSafepointVerifier nosafepoint;
|
|
return dictionary()->find(d_index, d_hash, class_name, loader_data,
|
|
protection_domain, THREAD);
|
|
}
|
|
}
|
|
|
|
|
|
// Look for a loaded instance or array klass by name. Do not do any loading.
|
|
// return NULL in case of error.
|
|
Klass* SystemDictionary::find_instance_or_array_klass(Symbol* class_name,
|
|
Handle class_loader,
|
|
Handle protection_domain,
|
|
TRAPS) {
|
|
Klass* k = NULL;
|
|
assert(class_name != NULL, "class name must be non NULL");
|
|
|
|
if (FieldType::is_array(class_name)) {
|
|
// The name refers to an array. Parse the name.
|
|
// dimension and object_key in FieldArrayInfo are assigned as a
|
|
// side-effect of this call
|
|
FieldArrayInfo fd;
|
|
BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL));
|
|
if (t != T_OBJECT) {
|
|
k = Universe::typeArrayKlassObj(t);
|
|
} else {
|
|
k = SystemDictionary::find(fd.object_key(), class_loader, protection_domain, THREAD);
|
|
}
|
|
if (k != NULL) {
|
|
k = k->array_klass_or_null(fd.dimension());
|
|
}
|
|
} else {
|
|
k = find(class_name, class_loader, protection_domain, THREAD);
|
|
}
|
|
return k;
|
|
}
|
|
|
|
// Note: this method is much like resolve_from_stream, but
|
|
// updates no supplemental data structures.
|
|
// TODO consolidate the two methods with a helper routine?
|
|
Klass* SystemDictionary::parse_stream(Symbol* class_name,
|
|
Handle class_loader,
|
|
Handle protection_domain,
|
|
ClassFileStream* st,
|
|
const Klass* host_klass,
|
|
GrowableArray<Handle>* cp_patches,
|
|
TRAPS) {
|
|
|
|
Ticks class_load_start_time = Ticks::now();
|
|
|
|
ClassLoaderData* loader_data;
|
|
if (host_klass != NULL) {
|
|
// Create a new CLD for anonymous class, that uses the same class loader
|
|
// as the host_klass
|
|
guarantee(host_klass->class_loader() == class_loader(), "should be the same");
|
|
guarantee(!DumpSharedSpaces, "must not create anonymous classes when dumping");
|
|
loader_data = ClassLoaderData::anonymous_class_loader_data(class_loader(), CHECK_NULL);
|
|
loader_data->record_dependency(host_klass, CHECK_NULL);
|
|
} else {
|
|
loader_data = ClassLoaderData::class_loader_data(class_loader());
|
|
}
|
|
|
|
assert(st != NULL, "invariant");
|
|
assert(st->need_verify(), "invariant");
|
|
|
|
// Parse stream and create a klass.
|
|
// Note that we do this even though this klass might
|
|
// already be present in the SystemDictionary, otherwise we would not
|
|
// throw potential ClassFormatErrors.
|
|
|
|
instanceKlassHandle k = KlassFactory::create_from_stream(st,
|
|
class_name,
|
|
loader_data,
|
|
protection_domain,
|
|
host_klass,
|
|
cp_patches,
|
|
NULL, // parsed_name
|
|
THREAD);
|
|
|
|
if (host_klass != NULL && k.not_null()) {
|
|
// If it's anonymous, initialize it now, since nobody else will.
|
|
|
|
{
|
|
MutexLocker mu_r(Compile_lock, THREAD);
|
|
|
|
// Add to class hierarchy, initialize vtables, and do possible
|
|
// deoptimizations.
|
|
add_to_hierarchy(k, CHECK_NULL); // No exception, but can block
|
|
|
|
// But, do not add to system dictionary.
|
|
|
|
// compiled code dependencies need to be validated anyway
|
|
notice_modification();
|
|
}
|
|
|
|
// Rewrite and patch constant pool here.
|
|
k->link_class(CHECK_NULL);
|
|
if (cp_patches != NULL) {
|
|
k->constants()->patch_resolved_references(cp_patches);
|
|
}
|
|
k->eager_initialize(CHECK_NULL);
|
|
|
|
// notify jvmti
|
|
if (JvmtiExport::should_post_class_load()) {
|
|
assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
|
|
JvmtiExport::post_class_load((JavaThread *) THREAD, k());
|
|
}
|
|
|
|
post_class_load_event(class_load_start_time, k, class_loader);
|
|
}
|
|
assert(host_klass != NULL || NULL == cp_patches,
|
|
"cp_patches only found with host_klass");
|
|
|
|
return k();
|
|
}
|
|
|
|
// Add a klass to the system from a stream (called by jni_DefineClass and
|
|
// JVM_DefineClass).
|
|
// Note: class_name can be NULL. In that case we do not know the name of
|
|
// the class until we have parsed the stream.
|
|
|
|
Klass* SystemDictionary::resolve_from_stream(Symbol* class_name,
|
|
Handle class_loader,
|
|
Handle protection_domain,
|
|
ClassFileStream* st,
|
|
TRAPS) {
|
|
|
|
// Classloaders that support parallelism, e.g. bootstrap classloader,
|
|
// or all classloaders with UnsyncloadClass do not acquire lock here
|
|
bool DoObjectLock = true;
|
|
if (is_parallelCapable(class_loader)) {
|
|
DoObjectLock = false;
|
|
}
|
|
|
|
ClassLoaderData* loader_data = register_loader(class_loader, CHECK_NULL);
|
|
|
|
// Make sure we are synchronized on the class loader before we proceed
|
|
Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
|
|
check_loader_lock_contention(lockObject, THREAD);
|
|
ObjectLocker ol(lockObject, THREAD, DoObjectLock);
|
|
|
|
assert(st != NULL, "invariant");
|
|
|
|
// Parse the stream and create a klass.
|
|
// Note that we do this even though this klass might
|
|
// already be present in the SystemDictionary, otherwise we would not
|
|
// throw potential ClassFormatErrors.
|
|
//
|
|
// Note: "parsed_name" is updated.
|
|
TempNewSymbol parsed_name = NULL;
|
|
|
|
instanceKlassHandle k;
|
|
|
|
#if INCLUDE_CDS
|
|
k = SystemDictionaryShared::lookup_from_stream(class_name,
|
|
class_loader,
|
|
protection_domain,
|
|
st,
|
|
CHECK_NULL);
|
|
#endif
|
|
|
|
if (k.not_null()) {
|
|
parsed_name = k->name();
|
|
} else {
|
|
if (st->buffer() == NULL) {
|
|
return NULL;
|
|
}
|
|
k = KlassFactory::create_from_stream(st,
|
|
class_name,
|
|
loader_data,
|
|
protection_domain,
|
|
NULL, // host_klass
|
|
NULL, // cp_patches
|
|
&parsed_name,
|
|
THREAD);
|
|
}
|
|
|
|
const char* pkg = "java/";
|
|
if (!HAS_PENDING_EXCEPTION &&
|
|
!class_loader.is_null() &&
|
|
!SystemDictionary::is_platform_class_loader(class_loader) &&
|
|
parsed_name != NULL &&
|
|
!strncmp((const char*)parsed_name->bytes(), pkg, strlen(pkg))) {
|
|
// It is illegal to define classes in the "java." package from
|
|
// JVM_DefineClass or jni_DefineClass unless you're the bootclassloader
|
|
ResourceMark rm(THREAD);
|
|
TempNewSymbol pkg_name = InstanceKlass::package_from_name(parsed_name, CHECK_NULL);
|
|
assert(pkg_name != NULL, "Error in parsing package name starting with 'java/'");
|
|
char* name = pkg_name->as_C_string();
|
|
StringUtils::replace_no_expand(name, "/", ".");
|
|
const char* msg_text = "Prohibited package name: ";
|
|
size_t len = strlen(msg_text) + strlen(name) + 1;
|
|
char* message = NEW_RESOURCE_ARRAY(char, len);
|
|
jio_snprintf(message, len, "%s%s", msg_text, name);
|
|
Exceptions::_throw_msg(THREAD_AND_LOCATION,
|
|
vmSymbols::java_lang_SecurityException(), message);
|
|
}
|
|
|
|
if (!HAS_PENDING_EXCEPTION) {
|
|
assert(parsed_name != NULL, "Sanity");
|
|
assert(class_name == NULL || class_name == parsed_name, "name mismatch");
|
|
// Verification prevents us from creating names with dots in them, this
|
|
// asserts that that's the case.
|
|
assert(is_internal_format(parsed_name),
|
|
"external class name format used internally");
|
|
|
|
// Add class just loaded
|
|
// If a class loader supports parallel classloading handle parallel define requests
|
|
// find_or_define_instance_class may return a different InstanceKlass
|
|
if (is_parallelCapable(class_loader)) {
|
|
k = find_or_define_instance_class(class_name, class_loader, k, THREAD);
|
|
} else {
|
|
define_instance_class(k, THREAD);
|
|
}
|
|
}
|
|
|
|
// Make sure we have an entry in the SystemDictionary on success
|
|
debug_only( {
|
|
if (!HAS_PENDING_EXCEPTION) {
|
|
assert(parsed_name != NULL, "parsed_name is still null?");
|
|
Symbol* h_name = k->name();
|
|
ClassLoaderData *defining_loader_data = k->class_loader_data();
|
|
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
|
|
Klass* check = find_class(parsed_name, loader_data);
|
|
assert(check == k(), "should be present in the dictionary");
|
|
|
|
Klass* check2 = find_class(h_name, defining_loader_data);
|
|
assert(check == check2, "name inconsistancy in SystemDictionary");
|
|
}
|
|
} );
|
|
|
|
return k();
|
|
}
|
|
|
|
#if INCLUDE_CDS
|
|
void SystemDictionary::set_shared_dictionary(HashtableBucket<mtClass>* t, int length,
|
|
int number_of_entries) {
|
|
assert(length == _nof_buckets * sizeof(HashtableBucket<mtClass>),
|
|
"bad shared dictionary size.");
|
|
_shared_dictionary = new Dictionary(_nof_buckets, t, number_of_entries);
|
|
}
|
|
|
|
|
|
// If there is a shared dictionary, then find the entry for the
|
|
// given shared system class, if any.
|
|
|
|
Klass* SystemDictionary::find_shared_class(Symbol* class_name) {
|
|
if (shared_dictionary() != NULL) {
|
|
unsigned int d_hash = shared_dictionary()->compute_hash(class_name, NULL);
|
|
int d_index = shared_dictionary()->hash_to_index(d_hash);
|
|
|
|
return shared_dictionary()->find_shared_class(d_index, d_hash, class_name);
|
|
} else {
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
|
|
// Load a class from the shared spaces (found through the shared system
|
|
// dictionary). Force the superclass and all interfaces to be loaded.
|
|
// Update the class definition to include sibling classes and no
|
|
// subclasses (yet). [Classes in the shared space are not part of the
|
|
// object hierarchy until loaded.]
|
|
|
|
instanceKlassHandle SystemDictionary::load_shared_class(
|
|
Symbol* class_name, Handle class_loader, TRAPS) {
|
|
instanceKlassHandle ik (THREAD, find_shared_class(class_name));
|
|
// Make sure we only return the boot class for the NULL classloader.
|
|
if (ik.not_null() &&
|
|
ik->is_shared_boot_class() && class_loader.is_null()) {
|
|
Handle protection_domain;
|
|
return load_shared_class(ik, class_loader, protection_domain, THREAD);
|
|
}
|
|
return instanceKlassHandle();
|
|
}
|
|
|
|
// Check if a shared class can be loaded by the specific classloader:
|
|
//
|
|
// NULL classloader:
|
|
// - Module class from "modules" jimage. ModuleEntry must be defined in the classloader.
|
|
// - Class from -Xbootclasspath/a. The class has no defined PackageEntry, or must
|
|
// be defined in an unnamed module.
|
|
bool SystemDictionary::is_shared_class_visible(Symbol* class_name,
|
|
instanceKlassHandle ik,
|
|
Handle class_loader, TRAPS) {
|
|
ResourceMark rm;
|
|
int path_index = ik->shared_classpath_index();
|
|
SharedClassPathEntry* ent =
|
|
(SharedClassPathEntry*)FileMapInfo::shared_classpath(path_index);
|
|
if (!Universe::is_module_initialized()) {
|
|
assert(ent->is_jrt(),
|
|
"Loading non-bootstrap classes before the module system is initialized");
|
|
assert(class_loader.is_null(), "sanity");
|
|
return true;
|
|
}
|
|
// Get the pkg_entry from the classloader
|
|
TempNewSymbol pkg_name = NULL;
|
|
PackageEntry* pkg_entry = NULL;
|
|
ModuleEntry* mod_entry = NULL;
|
|
const char* pkg_string = NULL;
|
|
ClassLoaderData* loader_data = class_loader_data(class_loader);
|
|
pkg_name = InstanceKlass::package_from_name(class_name, CHECK_false);
|
|
if (pkg_name != NULL) {
|
|
pkg_string = pkg_name->as_C_string();
|
|
if (loader_data != NULL) {
|
|
pkg_entry = loader_data->packages()->lookup_only(pkg_name);
|
|
}
|
|
if (pkg_entry != NULL) {
|
|
mod_entry = pkg_entry->module();
|
|
}
|
|
}
|
|
|
|
if (class_loader.is_null()) {
|
|
// The NULL classloader can load archived class originated from the
|
|
// "modules" jimage and the -Xbootclasspath/a. For class from the
|
|
// "modules" jimage, the PackageEntry/ModuleEntry must be defined
|
|
// by the NULL classloader.
|
|
if (mod_entry != NULL) {
|
|
// PackageEntry/ModuleEntry is found in the classloader. Check if the
|
|
// ModuleEntry's location agrees with the archived class' origination.
|
|
if (ent->is_jrt() && mod_entry->location()->starts_with("jrt:")) {
|
|
return true; // Module class from the "module" jimage
|
|
}
|
|
}
|
|
|
|
// If the archived class is not from the "module" jimage, the class can be
|
|
// loaded by the NULL classloader if
|
|
//
|
|
// 1. the class is from the unamed package
|
|
// 2. or, the class is not from a module defined in the NULL classloader
|
|
// 3. or, the class is from an unamed module
|
|
if (!ent->is_jrt() && ik->is_shared_boot_class()) {
|
|
// the class is from the -Xbootclasspath/a
|
|
if (pkg_string == NULL ||
|
|
pkg_entry == NULL ||
|
|
pkg_entry->in_unnamed_module()) {
|
|
assert(mod_entry == NULL ||
|
|
mod_entry == loader_data->modules()->unnamed_module(),
|
|
"the unnamed module is not defined in the classloader");
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
} else {
|
|
bool res = SystemDictionaryShared::is_shared_class_visible_for_classloader(
|
|
ik, class_loader, pkg_string, pkg_name,
|
|
pkg_entry, mod_entry, CHECK_(false));
|
|
return res;
|
|
}
|
|
}
|
|
|
|
instanceKlassHandle SystemDictionary::load_shared_class(instanceKlassHandle ik,
|
|
Handle class_loader,
|
|
Handle protection_domain, TRAPS) {
|
|
if (ik.not_null()) {
|
|
instanceKlassHandle nh = instanceKlassHandle(); // null Handle
|
|
Symbol* class_name = ik->name();
|
|
|
|
bool visible = is_shared_class_visible(
|
|
class_name, ik, class_loader, CHECK_(nh));
|
|
if (!visible) {
|
|
return nh;
|
|
}
|
|
|
|
// Resolve the superclass and interfaces. They must be the same
|
|
// as in dump time, because the layout of <ik> depends on
|
|
// the specific layout of ik->super() and ik->local_interfaces().
|
|
//
|
|
// If unexpected superclass or interfaces are found, we cannot
|
|
// load <ik> from the shared archive.
|
|
|
|
if (ik->super() != NULL) {
|
|
Symbol* cn = ik->super()->name();
|
|
Klass *s = resolve_super_or_fail(class_name, cn,
|
|
class_loader, protection_domain, true, CHECK_(nh));
|
|
if (s != ik->super()) {
|
|
// The dynamically resolved super class is not the same as the one we used during dump time,
|
|
// so we cannot use ik.
|
|
return nh;
|
|
} else {
|
|
assert(s->is_shared(), "must be");
|
|
}
|
|
}
|
|
|
|
Array<Klass*>* interfaces = ik->local_interfaces();
|
|
int num_interfaces = interfaces->length();
|
|
for (int index = 0; index < num_interfaces; index++) {
|
|
Klass* k = interfaces->at(index);
|
|
|
|
// Note: can not use InstanceKlass::cast here because
|
|
// interfaces' InstanceKlass's C++ vtbls haven't been
|
|
// reinitialized yet (they will be once the interface classes
|
|
// are loaded)
|
|
Symbol* name = k->name();
|
|
Klass* i = resolve_super_or_fail(class_name, name, class_loader, protection_domain, false, CHECK_(nh));
|
|
if (k != i) {
|
|
// The dynamically resolved interface class is not the same as the one we used during dump time,
|
|
// so we cannot use ik.
|
|
return nh;
|
|
} else {
|
|
assert(i->is_shared(), "must be");
|
|
}
|
|
}
|
|
|
|
// Adjust methods to recover missing data. They need addresses for
|
|
// interpreter entry points and their default native method address
|
|
// must be reset.
|
|
|
|
// Updating methods must be done under a lock so multiple
|
|
// threads don't update these in parallel
|
|
//
|
|
// Shared classes are all currently loaded by either the bootstrap or
|
|
// internal parallel class loaders, so this will never cause a deadlock
|
|
// on a custom class loader lock.
|
|
|
|
ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
|
|
{
|
|
Handle lockObject = compute_loader_lock_object(class_loader, THREAD);
|
|
check_loader_lock_contention(lockObject, THREAD);
|
|
ObjectLocker ol(lockObject, THREAD, true);
|
|
ik->restore_unshareable_info(loader_data, protection_domain, CHECK_(nh));
|
|
}
|
|
|
|
if (log_is_enabled(Info, class, load)) {
|
|
ik()->print_loading_log(LogLevel::Info, loader_data, NULL, NULL);
|
|
}
|
|
// No 'else' here as logging levels are not mutually exclusive
|
|
|
|
if (log_is_enabled(Debug, class, load)) {
|
|
ik()->print_loading_log(LogLevel::Debug, loader_data, NULL, NULL);
|
|
}
|
|
|
|
// For boot loader, ensure that GetSystemPackage knows that a class in this
|
|
// package was loaded.
|
|
if (class_loader.is_null()) {
|
|
int path_index = ik->shared_classpath_index();
|
|
ResourceMark rm;
|
|
ClassLoader::add_package(ik->name()->as_C_string(), path_index, THREAD);
|
|
}
|
|
|
|
if (DumpLoadedClassList != NULL && classlist_file->is_open()) {
|
|
// Only dump the classes that can be stored into CDS archive
|
|
if (SystemDictionaryShared::is_sharing_possible(loader_data)) {
|
|
ResourceMark rm(THREAD);
|
|
classlist_file->print_cr("%s", ik->name()->as_C_string());
|
|
classlist_file->flush();
|
|
}
|
|
}
|
|
|
|
// notify a class loaded from shared object
|
|
ClassLoadingService::notify_class_loaded(ik(), true /* shared class */);
|
|
}
|
|
return ik;
|
|
}
|
|
#endif // INCLUDE_CDS
|
|
|
|
instanceKlassHandle SystemDictionary::load_instance_class(Symbol* class_name, Handle class_loader, TRAPS) {
|
|
instanceKlassHandle nh = instanceKlassHandle(); // null Handle
|
|
|
|
if (class_loader.is_null()) {
|
|
ResourceMark rm;
|
|
PackageEntry* pkg_entry = NULL;
|
|
bool search_only_bootloader_append = false;
|
|
ClassLoaderData *loader_data = class_loader_data(class_loader);
|
|
|
|
// Find the package in the boot loader's package entry table.
|
|
TempNewSymbol pkg_name = InstanceKlass::package_from_name(class_name, CHECK_NULL);
|
|
if (pkg_name != NULL) {
|
|
pkg_entry = loader_data->packages()->lookup_only(pkg_name);
|
|
}
|
|
|
|
// Prior to attempting to load the class, enforce the boot loader's
|
|
// visibility boundaries.
|
|
if (!Universe::is_module_initialized()) {
|
|
// During bootstrapping, prior to module initialization, any
|
|
// class attempting to be loaded must be checked against the
|
|
// java.base packages in the boot loader's PackageEntryTable.
|
|
// No class outside of java.base is allowed to be loaded during
|
|
// this bootstrapping window.
|
|
if (!DumpSharedSpaces) {
|
|
if (pkg_entry == NULL || pkg_entry->in_unnamed_module()) {
|
|
// Class is either in the unnamed package or in
|
|
// a named package within the unnamed module. Either
|
|
// case is outside of java.base, do not attempt to
|
|
// load the class post java.base definition. If
|
|
// java.base has not been defined, let the class load
|
|
// and its package will be checked later by
|
|
// ModuleEntryTable::verify_javabase_packages.
|
|
if (ModuleEntryTable::javabase_defined()) {
|
|
return nh;
|
|
}
|
|
} else {
|
|
// Check that the class' package is defined within java.base.
|
|
ModuleEntry* mod_entry = pkg_entry->module();
|
|
Symbol* mod_entry_name = mod_entry->name();
|
|
if (mod_entry_name->fast_compare(vmSymbols::java_base()) != 0) {
|
|
return nh;
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
assert(!DumpSharedSpaces, "Archive dumped after module system initialization");
|
|
// After the module system has been initialized, check if the class'
|
|
// package is in a module defined to the boot loader.
|
|
if (pkg_name == NULL || pkg_entry == NULL || pkg_entry->in_unnamed_module()) {
|
|
// Class is either in the unnamed package, in a named package
|
|
// within a module not defined to the boot loader or in a
|
|
// a named package within the unnamed module. In all cases,
|
|
// limit visibility to search for the class only in the boot
|
|
// loader's append path.
|
|
search_only_bootloader_append = true;
|
|
}
|
|
}
|
|
|
|
// Prior to bootstrapping's module initialization, never load a class outside
|
|
// of the boot loader's module path
|
|
assert(Universe::is_module_initialized() || DumpSharedSpaces ||
|
|
!search_only_bootloader_append,
|
|
"Attempt to load a class outside of boot loader's module path");
|
|
|
|
// Search the shared system dictionary for classes preloaded into the
|
|
// shared spaces.
|
|
instanceKlassHandle k;
|
|
{
|
|
#if INCLUDE_CDS
|
|
PerfTraceTime vmtimer(ClassLoader::perf_shared_classload_time());
|
|
k = load_shared_class(class_name, class_loader, THREAD);
|
|
#endif
|
|
}
|
|
|
|
if (k.is_null()) {
|
|
// Use VM class loader
|
|
PerfTraceTime vmtimer(ClassLoader::perf_sys_classload_time());
|
|
k = ClassLoader::load_class(class_name, search_only_bootloader_append, CHECK_(nh));
|
|
}
|
|
|
|
// find_or_define_instance_class may return a different InstanceKlass
|
|
if (!k.is_null()) {
|
|
k = find_or_define_instance_class(class_name, class_loader, k, CHECK_(nh));
|
|
}
|
|
return k;
|
|
} else {
|
|
// Use user specified class loader to load class. Call loadClass operation on class_loader.
|
|
ResourceMark rm(THREAD);
|
|
|
|
assert(THREAD->is_Java_thread(), "must be a JavaThread");
|
|
JavaThread* jt = (JavaThread*) THREAD;
|
|
|
|
PerfClassTraceTime vmtimer(ClassLoader::perf_app_classload_time(),
|
|
ClassLoader::perf_app_classload_selftime(),
|
|
ClassLoader::perf_app_classload_count(),
|
|
jt->get_thread_stat()->perf_recursion_counts_addr(),
|
|
jt->get_thread_stat()->perf_timers_addr(),
|
|
PerfClassTraceTime::CLASS_LOAD);
|
|
|
|
Handle s = java_lang_String::create_from_symbol(class_name, CHECK_(nh));
|
|
// Translate to external class name format, i.e., convert '/' chars to '.'
|
|
Handle string = java_lang_String::externalize_classname(s, CHECK_(nh));
|
|
|
|
JavaValue result(T_OBJECT);
|
|
|
|
KlassHandle spec_klass (THREAD, SystemDictionary::ClassLoader_klass());
|
|
|
|
// Call public unsynchronized loadClass(String) directly for all class loaders
|
|
// for parallelCapable class loaders. JDK >=7, loadClass(String, boolean) will
|
|
// acquire a class-name based lock rather than the class loader object lock.
|
|
// JDK < 7 already acquire the class loader lock in loadClass(String, boolean),
|
|
// so the call to loadClassInternal() was not required.
|
|
//
|
|
// UnsyncloadClass flag means both call loadClass(String) and do
|
|
// not acquire the class loader lock even for class loaders that are
|
|
// not parallelCapable. This was a risky transitional
|
|
// flag for diagnostic purposes only. It is risky to call
|
|
// custom class loaders without synchronization.
|
|
// WARNING If a custom class loader does NOT synchronizer findClass, or callers of
|
|
// findClass, the UnsyncloadClass flag risks unexpected timing bugs in the field.
|
|
// Do NOT assume this will be supported in future releases.
|
|
//
|
|
// Added MustCallLoadClassInternal in case we discover in the field
|
|
// a customer that counts on this call
|
|
if (MustCallLoadClassInternal && has_loadClassInternal()) {
|
|
JavaCalls::call_special(&result,
|
|
class_loader,
|
|
spec_klass,
|
|
vmSymbols::loadClassInternal_name(),
|
|
vmSymbols::string_class_signature(),
|
|
string,
|
|
CHECK_(nh));
|
|
} else {
|
|
JavaCalls::call_virtual(&result,
|
|
class_loader,
|
|
spec_klass,
|
|
vmSymbols::loadClass_name(),
|
|
vmSymbols::string_class_signature(),
|
|
string,
|
|
CHECK_(nh));
|
|
}
|
|
|
|
assert(result.get_type() == T_OBJECT, "just checking");
|
|
oop obj = (oop) result.get_jobject();
|
|
|
|
// Primitive classes return null since forName() can not be
|
|
// used to obtain any of the Class objects representing primitives or void
|
|
if ((obj != NULL) && !(java_lang_Class::is_primitive(obj))) {
|
|
instanceKlassHandle k =
|
|
instanceKlassHandle(THREAD, java_lang_Class::as_Klass(obj));
|
|
// For user defined Java class loaders, check that the name returned is
|
|
// the same as that requested. This check is done for the bootstrap
|
|
// loader when parsing the class file.
|
|
if (class_name == k->name()) {
|
|
return k;
|
|
}
|
|
}
|
|
// Class is not found or has the wrong name, return NULL
|
|
return nh;
|
|
}
|
|
}
|
|
|
|
void SystemDictionary::define_instance_class(instanceKlassHandle k, TRAPS) {
|
|
|
|
ClassLoaderData* loader_data = k->class_loader_data();
|
|
Handle class_loader_h(THREAD, loader_data->class_loader());
|
|
|
|
// for bootstrap and other parallel classloaders don't acquire lock,
|
|
// use placeholder token
|
|
// If a parallelCapable class loader calls define_instance_class instead of
|
|
// find_or_define_instance_class to get here, we have a timing
|
|
// hole with systemDictionary updates and check_constraints
|
|
if (!class_loader_h.is_null() && !is_parallelCapable(class_loader_h)) {
|
|
assert(ObjectSynchronizer::current_thread_holds_lock((JavaThread*)THREAD,
|
|
compute_loader_lock_object(class_loader_h, THREAD)),
|
|
"define called without lock");
|
|
}
|
|
|
|
// Check class-loading constraints. Throw exception if violation is detected.
|
|
// Grabs and releases SystemDictionary_lock
|
|
// The check_constraints/find_class call and update_dictionary sequence
|
|
// must be "atomic" for a specific class/classloader pair so we never
|
|
// define two different instanceKlasses for that class/classloader pair.
|
|
// Existing classloaders will call define_instance_class with the
|
|
// classloader lock held
|
|
// Parallel classloaders will call find_or_define_instance_class
|
|
// which will require a token to perform the define class
|
|
Symbol* name_h = k->name();
|
|
unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data);
|
|
int d_index = dictionary()->hash_to_index(d_hash);
|
|
check_constraints(d_index, d_hash, k, class_loader_h, true, CHECK);
|
|
|
|
// Register class just loaded with class loader (placed in Vector)
|
|
// Note we do this before updating the dictionary, as this can
|
|
// fail with an OutOfMemoryError (if it does, we will *not* put this
|
|
// class in the dictionary and will not update the class hierarchy).
|
|
// JVMTI FollowReferences needs to find the classes this way.
|
|
if (k->class_loader() != NULL) {
|
|
methodHandle m(THREAD, Universe::loader_addClass_method());
|
|
JavaValue result(T_VOID);
|
|
JavaCallArguments args(class_loader_h);
|
|
args.push_oop(Handle(THREAD, k->java_mirror()));
|
|
JavaCalls::call(&result, m, &args, CHECK);
|
|
}
|
|
|
|
// Add the new class. We need recompile lock during update of CHA.
|
|
{
|
|
unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data);
|
|
int p_index = placeholders()->hash_to_index(p_hash);
|
|
|
|
MutexLocker mu_r(Compile_lock, THREAD);
|
|
|
|
// Add to class hierarchy, initialize vtables, and do possible
|
|
// deoptimizations.
|
|
add_to_hierarchy(k, CHECK); // No exception, but can block
|
|
|
|
// Add to systemDictionary - so other classes can see it.
|
|
// Grabs and releases SystemDictionary_lock
|
|
update_dictionary(d_index, d_hash, p_index, p_hash,
|
|
k, class_loader_h, THREAD);
|
|
}
|
|
k->eager_initialize(THREAD);
|
|
|
|
// notify jvmti
|
|
if (JvmtiExport::should_post_class_load()) {
|
|
assert(THREAD->is_Java_thread(), "thread->is_Java_thread()");
|
|
JvmtiExport::post_class_load((JavaThread *) THREAD, k());
|
|
|
|
}
|
|
|
|
TRACE_KLASS_DEFINITION(k, THREAD);
|
|
|
|
}
|
|
|
|
// Support parallel classloading
|
|
// All parallel class loaders, including bootstrap classloader
|
|
// lock a placeholder entry for this class/class_loader pair
|
|
// to allow parallel defines of different classes for this class loader
|
|
// With AllowParallelDefine flag==true, in case they do not synchronize around
|
|
// FindLoadedClass/DefineClass, calls, we check for parallel
|
|
// loading for them, wait if a defineClass is in progress
|
|
// and return the initial requestor's results
|
|
// This flag does not apply to the bootstrap classloader.
|
|
// With AllowParallelDefine flag==false, call through to define_instance_class
|
|
// which will throw LinkageError: duplicate class definition.
|
|
// False is the requested default.
|
|
// For better performance, the class loaders should synchronize
|
|
// findClass(), i.e. FindLoadedClass/DefineClassIfAbsent or they
|
|
// potentially waste time reading and parsing the bytestream.
|
|
// Note: VM callers should ensure consistency of k/class_name,class_loader
|
|
instanceKlassHandle SystemDictionary::find_or_define_instance_class(Symbol* class_name, Handle class_loader, instanceKlassHandle k, TRAPS) {
|
|
|
|
instanceKlassHandle nh = instanceKlassHandle(); // null Handle
|
|
Symbol* name_h = k->name(); // passed in class_name may be null
|
|
ClassLoaderData* loader_data = class_loader_data(class_loader);
|
|
|
|
unsigned int d_hash = dictionary()->compute_hash(name_h, loader_data);
|
|
int d_index = dictionary()->hash_to_index(d_hash);
|
|
|
|
// Hold SD lock around find_class and placeholder creation for DEFINE_CLASS
|
|
unsigned int p_hash = placeholders()->compute_hash(name_h, loader_data);
|
|
int p_index = placeholders()->hash_to_index(p_hash);
|
|
PlaceholderEntry* probe;
|
|
|
|
{
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
// First check if class already defined
|
|
if (UnsyncloadClass || (is_parallelDefine(class_loader))) {
|
|
Klass* check = find_class(d_index, d_hash, name_h, loader_data);
|
|
if (check != NULL) {
|
|
return(instanceKlassHandle(THREAD, check));
|
|
}
|
|
}
|
|
|
|
// Acquire define token for this class/classloader
|
|
probe = placeholders()->find_and_add(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, NULL, THREAD);
|
|
// Wait if another thread defining in parallel
|
|
// All threads wait - even those that will throw duplicate class: otherwise
|
|
// caller is surprised by LinkageError: duplicate, but findLoadedClass fails
|
|
// if other thread has not finished updating dictionary
|
|
while (probe->definer() != NULL) {
|
|
SystemDictionary_lock->wait();
|
|
}
|
|
// Only special cases allow parallel defines and can use other thread's results
|
|
// Other cases fall through, and may run into duplicate defines
|
|
// caught by finding an entry in the SystemDictionary
|
|
if ((UnsyncloadClass || is_parallelDefine(class_loader)) && (probe->instance_klass() != NULL)) {
|
|
placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
|
|
SystemDictionary_lock->notify_all();
|
|
#ifdef ASSERT
|
|
Klass* check = find_class(d_index, d_hash, name_h, loader_data);
|
|
assert(check != NULL, "definer missed recording success");
|
|
#endif
|
|
return(instanceKlassHandle(THREAD, probe->instance_klass()));
|
|
} else {
|
|
// This thread will define the class (even if earlier thread tried and had an error)
|
|
probe->set_definer(THREAD);
|
|
}
|
|
}
|
|
|
|
define_instance_class(k, THREAD);
|
|
|
|
Handle linkage_exception = Handle(); // null handle
|
|
|
|
// definer must notify any waiting threads
|
|
{
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, name_h, loader_data);
|
|
assert(probe != NULL, "DEFINE_CLASS placeholder lost?");
|
|
if (probe != NULL) {
|
|
if (HAS_PENDING_EXCEPTION) {
|
|
linkage_exception = Handle(THREAD,PENDING_EXCEPTION);
|
|
CLEAR_PENDING_EXCEPTION;
|
|
} else {
|
|
probe->set_instance_klass(k());
|
|
}
|
|
probe->set_definer(NULL);
|
|
placeholders()->find_and_remove(p_index, p_hash, name_h, loader_data, PlaceholderTable::DEFINE_CLASS, THREAD);
|
|
SystemDictionary_lock->notify_all();
|
|
}
|
|
}
|
|
|
|
// Can't throw exception while holding lock due to rank ordering
|
|
if (linkage_exception() != NULL) {
|
|
THROW_OOP_(linkage_exception(), nh); // throws exception and returns
|
|
}
|
|
|
|
return k;
|
|
}
|
|
Handle SystemDictionary::compute_loader_lock_object(Handle class_loader, TRAPS) {
|
|
// If class_loader is NULL we synchronize on _system_loader_lock_obj
|
|
if (class_loader.is_null()) {
|
|
return Handle(THREAD, _system_loader_lock_obj);
|
|
} else {
|
|
return class_loader;
|
|
}
|
|
}
|
|
|
|
// This method is added to check how often we have to wait to grab loader
|
|
// lock. The results are being recorded in the performance counters defined in
|
|
// ClassLoader::_sync_systemLoaderLockContentionRate and
|
|
// ClassLoader::_sync_nonSystemLoaderLockConteionRate.
|
|
void SystemDictionary::check_loader_lock_contention(Handle loader_lock, TRAPS) {
|
|
if (!UsePerfData) {
|
|
return;
|
|
}
|
|
|
|
assert(!loader_lock.is_null(), "NULL lock object");
|
|
|
|
if (ObjectSynchronizer::query_lock_ownership((JavaThread*)THREAD, loader_lock)
|
|
== ObjectSynchronizer::owner_other) {
|
|
// contention will likely happen, so increment the corresponding
|
|
// contention counter.
|
|
if (loader_lock() == _system_loader_lock_obj) {
|
|
ClassLoader::sync_systemLoaderLockContentionRate()->inc();
|
|
} else {
|
|
ClassLoader::sync_nonSystemLoaderLockContentionRate()->inc();
|
|
}
|
|
}
|
|
}
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// Lookup
|
|
|
|
Klass* SystemDictionary::find_class(int index, unsigned int hash,
|
|
Symbol* class_name,
|
|
ClassLoaderData* loader_data) {
|
|
assert_locked_or_safepoint(SystemDictionary_lock);
|
|
assert (index == dictionary()->index_for(class_name, loader_data),
|
|
"incorrect index?");
|
|
|
|
Klass* k = dictionary()->find_class(index, hash, class_name, loader_data);
|
|
return k;
|
|
}
|
|
|
|
|
|
// Basic find on classes in the midst of being loaded
|
|
Symbol* SystemDictionary::find_placeholder(Symbol* class_name,
|
|
ClassLoaderData* loader_data) {
|
|
assert_locked_or_safepoint(SystemDictionary_lock);
|
|
unsigned int p_hash = placeholders()->compute_hash(class_name, loader_data);
|
|
int p_index = placeholders()->hash_to_index(p_hash);
|
|
return placeholders()->find_entry(p_index, p_hash, class_name, loader_data);
|
|
}
|
|
|
|
|
|
// Used for assertions and verification only
|
|
Klass* SystemDictionary::find_class(Symbol* class_name, ClassLoaderData* loader_data) {
|
|
#ifndef ASSERT
|
|
guarantee(VerifyBeforeGC ||
|
|
VerifyDuringGC ||
|
|
VerifyBeforeExit ||
|
|
VerifyDuringStartup ||
|
|
VerifyAfterGC, "too expensive");
|
|
#endif
|
|
assert_locked_or_safepoint(SystemDictionary_lock);
|
|
|
|
// First look in the loaded class array
|
|
unsigned int d_hash = dictionary()->compute_hash(class_name, loader_data);
|
|
int d_index = dictionary()->hash_to_index(d_hash);
|
|
return find_class(d_index, d_hash, class_name, loader_data);
|
|
}
|
|
|
|
|
|
// Get the next class in the dictionary.
|
|
Klass* SystemDictionary::try_get_next_class() {
|
|
return dictionary()->try_get_next_class();
|
|
}
|
|
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// Update hierachy. This is done before the new klass has been added to the SystemDictionary. The Recompile_lock
|
|
// is held, to ensure that the compiler is not using the class hierachy, and that deoptimization will kick in
|
|
// before a new class is used.
|
|
|
|
void SystemDictionary::add_to_hierarchy(instanceKlassHandle k, TRAPS) {
|
|
assert(k.not_null(), "just checking");
|
|
assert_locked_or_safepoint(Compile_lock);
|
|
|
|
// Link into hierachy. Make sure the vtables are initialized before linking into
|
|
k->append_to_sibling_list(); // add to superklass/sibling list
|
|
k->process_interfaces(THREAD); // handle all "implements" declarations
|
|
k->set_init_state(InstanceKlass::loaded);
|
|
// Now flush all code that depended on old class hierarchy.
|
|
// Note: must be done *after* linking k into the hierarchy (was bug 12/9/97)
|
|
// Also, first reinitialize vtable because it may have gotten out of synch
|
|
// while the new class wasn't connected to the class hierarchy.
|
|
CodeCache::flush_dependents_on(k);
|
|
}
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// GC support
|
|
|
|
// Following roots during mark-sweep is separated in two phases.
|
|
//
|
|
// The first phase follows preloaded classes and all other system
|
|
// classes, since these will never get unloaded anyway.
|
|
//
|
|
// The second phase removes (unloads) unreachable classes from the
|
|
// system dictionary and follows the remaining classes' contents.
|
|
|
|
void SystemDictionary::always_strong_oops_do(OopClosure* blk) {
|
|
roots_oops_do(blk, NULL);
|
|
}
|
|
|
|
void SystemDictionary::always_strong_classes_do(KlassClosure* closure) {
|
|
// Follow all system classes and temporary placeholders in dictionary
|
|
dictionary()->always_strong_classes_do(closure);
|
|
|
|
// Placeholders. These represent classes we're actively loading.
|
|
placeholders()->classes_do(closure);
|
|
}
|
|
|
|
// Calculate a "good" systemdictionary size based
|
|
// on predicted or current loaded classes count
|
|
int SystemDictionary::calculate_systemdictionary_size(int classcount) {
|
|
int newsize = _old_default_sdsize;
|
|
if ((classcount > 0) && !DumpSharedSpaces) {
|
|
int desiredsize = classcount/_average_depth_goal;
|
|
for (newsize = _primelist[_sdgeneration]; _sdgeneration < _prime_array_size -1;
|
|
newsize = _primelist[++_sdgeneration]) {
|
|
if (desiredsize <= newsize) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
return newsize;
|
|
}
|
|
|
|
#ifdef ASSERT
|
|
class VerifySDReachableAndLiveClosure : public OopClosure {
|
|
private:
|
|
BoolObjectClosure* _is_alive;
|
|
|
|
template <class T> void do_oop_work(T* p) {
|
|
oop obj = oopDesc::load_decode_heap_oop(p);
|
|
guarantee(_is_alive->do_object_b(obj), "Oop in system dictionary must be live");
|
|
}
|
|
|
|
public:
|
|
VerifySDReachableAndLiveClosure(BoolObjectClosure* is_alive) : OopClosure(), _is_alive(is_alive) { }
|
|
|
|
virtual void do_oop(oop* p) { do_oop_work(p); }
|
|
virtual void do_oop(narrowOop* p) { do_oop_work(p); }
|
|
};
|
|
#endif
|
|
|
|
// Assumes classes in the SystemDictionary are only unloaded at a safepoint
|
|
// Note: anonymous classes are not in the SD.
|
|
bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive,
|
|
bool clean_previous_versions) {
|
|
// First, mark for unload all ClassLoaderData referencing a dead class loader.
|
|
bool unloading_occurred = ClassLoaderDataGraph::do_unloading(is_alive,
|
|
clean_previous_versions);
|
|
if (unloading_occurred) {
|
|
dictionary()->do_unloading();
|
|
constraints()->purge_loader_constraints();
|
|
resolution_errors()->purge_resolution_errors();
|
|
}
|
|
// Oops referenced by the system dictionary may get unreachable independently
|
|
// of the class loader (eg. cached protection domain oops). So we need to
|
|
// explicitly unlink them here instead of in Dictionary::do_unloading.
|
|
dictionary()->unlink(is_alive);
|
|
#ifdef ASSERT
|
|
VerifySDReachableAndLiveClosure cl(is_alive);
|
|
dictionary()->oops_do(&cl);
|
|
#endif
|
|
return unloading_occurred;
|
|
}
|
|
|
|
void SystemDictionary::roots_oops_do(OopClosure* strong, OopClosure* weak) {
|
|
strong->do_oop(&_java_system_loader);
|
|
strong->do_oop(&_system_loader_lock_obj);
|
|
CDS_ONLY(SystemDictionaryShared::roots_oops_do(strong);)
|
|
|
|
// Adjust dictionary
|
|
dictionary()->roots_oops_do(strong, weak);
|
|
|
|
// Visit extra methods
|
|
invoke_method_table()->oops_do(strong);
|
|
}
|
|
|
|
void SystemDictionary::oops_do(OopClosure* f) {
|
|
f->do_oop(&_java_system_loader);
|
|
f->do_oop(&_system_loader_lock_obj);
|
|
CDS_ONLY(SystemDictionaryShared::oops_do(f);)
|
|
|
|
// Adjust dictionary
|
|
dictionary()->oops_do(f);
|
|
|
|
// Visit extra methods
|
|
invoke_method_table()->oops_do(f);
|
|
}
|
|
|
|
// Extended Class redefinition support.
|
|
// If one of these classes is replaced, we need to replace it in these places.
|
|
// KlassClosure::do_klass should take the address of a class but we can
|
|
// change that later.
|
|
void SystemDictionary::preloaded_classes_do(KlassClosure* f) {
|
|
for (int k = (int)FIRST_WKID; k < (int)WKID_LIMIT; k++) {
|
|
f->do_klass(_well_known_klasses[k]);
|
|
}
|
|
|
|
{
|
|
for (int i = 0; i < T_VOID+1; i++) {
|
|
if (_box_klasses[i] != NULL) {
|
|
assert(i >= T_BOOLEAN, "checking");
|
|
f->do_klass(_box_klasses[i]);
|
|
}
|
|
}
|
|
}
|
|
|
|
FilteredFieldsMap::classes_do(f);
|
|
}
|
|
|
|
void SystemDictionary::lazily_loaded_classes_do(KlassClosure* f) {
|
|
f->do_klass(_abstract_ownable_synchronizer_klass);
|
|
}
|
|
|
|
// Just the classes from defining class loaders
|
|
// Don't iterate over placeholders
|
|
void SystemDictionary::classes_do(void f(Klass*)) {
|
|
dictionary()->classes_do(f);
|
|
}
|
|
|
|
// Added for initialize_itable_for_klass
|
|
// Just the classes from defining class loaders
|
|
// Don't iterate over placeholders
|
|
void SystemDictionary::classes_do(void f(Klass*, TRAPS), TRAPS) {
|
|
dictionary()->classes_do(f, CHECK);
|
|
}
|
|
|
|
// All classes, and their class loaders
|
|
// Don't iterate over placeholders
|
|
void SystemDictionary::classes_do(void f(Klass*, ClassLoaderData*)) {
|
|
dictionary()->classes_do(f);
|
|
}
|
|
|
|
void SystemDictionary::placeholders_do(void f(Symbol*)) {
|
|
placeholders()->entries_do(f);
|
|
}
|
|
|
|
void SystemDictionary::methods_do(void f(Method*)) {
|
|
dictionary()->methods_do(f);
|
|
invoke_method_table()->methods_do(f);
|
|
}
|
|
|
|
void SystemDictionary::remove_classes_in_error_state() {
|
|
dictionary()->remove_classes_in_error_state();
|
|
}
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// Lazily load klasses
|
|
|
|
void SystemDictionary::load_abstract_ownable_synchronizer_klass(TRAPS) {
|
|
// if multiple threads calling this function, only one thread will load
|
|
// the class. The other threads will find the loaded version once the
|
|
// class is loaded.
|
|
Klass* aos = _abstract_ownable_synchronizer_klass;
|
|
if (aos == NULL) {
|
|
Klass* k = resolve_or_fail(vmSymbols::java_util_concurrent_locks_AbstractOwnableSynchronizer(), true, CHECK);
|
|
// Force a fence to prevent any read before the write completes
|
|
OrderAccess::fence();
|
|
_abstract_ownable_synchronizer_klass = InstanceKlass::cast(k);
|
|
}
|
|
}
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// Initialization
|
|
|
|
void SystemDictionary::initialize(TRAPS) {
|
|
// Allocate arrays
|
|
assert(dictionary() == NULL,
|
|
"SystemDictionary should only be initialized once");
|
|
_sdgeneration = 0;
|
|
_dictionary = new Dictionary(calculate_systemdictionary_size(PredictedLoadedClassCount));
|
|
_placeholders = new PlaceholderTable(_nof_buckets);
|
|
_number_of_modifications = 0;
|
|
_loader_constraints = new LoaderConstraintTable(_loader_constraint_size);
|
|
_resolution_errors = new ResolutionErrorTable(_resolution_error_size);
|
|
_invoke_method_table = new SymbolPropertyTable(_invoke_method_size);
|
|
|
|
// Allocate private object used as system class loader lock
|
|
_system_loader_lock_obj = oopFactory::new_intArray(0, CHECK);
|
|
// Initialize basic classes
|
|
initialize_preloaded_classes(CHECK);
|
|
}
|
|
|
|
// Compact table of directions on the initialization of klasses:
|
|
static const short wk_init_info[] = {
|
|
#define WK_KLASS_INIT_INFO(name, symbol, option) \
|
|
( ((int)vmSymbols::VM_SYMBOL_ENUM_NAME(symbol) \
|
|
<< SystemDictionary::CEIL_LG_OPTION_LIMIT) \
|
|
| (int)SystemDictionary::option ),
|
|
WK_KLASSES_DO(WK_KLASS_INIT_INFO)
|
|
#undef WK_KLASS_INIT_INFO
|
|
0
|
|
};
|
|
|
|
bool SystemDictionary::initialize_wk_klass(WKID id, int init_opt, TRAPS) {
|
|
assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
|
|
int info = wk_init_info[id - FIRST_WKID];
|
|
int sid = (info >> CEIL_LG_OPTION_LIMIT);
|
|
Symbol* symbol = vmSymbols::symbol_at((vmSymbols::SID)sid);
|
|
InstanceKlass** klassp = &_well_known_klasses[id];
|
|
|
|
bool must_load;
|
|
#if INCLUDE_JVMCI
|
|
if (EnableJVMCI) {
|
|
// If JVMCI is enabled we require its classes to be found.
|
|
must_load = (init_opt < SystemDictionary::Opt) || (init_opt == SystemDictionary::Jvmci);
|
|
} else
|
|
#endif
|
|
{
|
|
must_load = (init_opt < SystemDictionary::Opt);
|
|
}
|
|
|
|
if ((*klassp) == NULL) {
|
|
Klass* k;
|
|
if (must_load) {
|
|
k = resolve_or_fail(symbol, true, CHECK_0); // load required class
|
|
} else {
|
|
k = resolve_or_null(symbol, CHECK_0); // load optional klass
|
|
}
|
|
(*klassp) = (k == NULL) ? NULL : InstanceKlass::cast(k);
|
|
}
|
|
return ((*klassp) != NULL);
|
|
}
|
|
|
|
void SystemDictionary::initialize_wk_klasses_until(WKID limit_id, WKID &start_id, TRAPS) {
|
|
assert((int)start_id <= (int)limit_id, "IDs are out of order!");
|
|
for (int id = (int)start_id; id < (int)limit_id; id++) {
|
|
assert(id >= (int)FIRST_WKID && id < (int)WKID_LIMIT, "oob");
|
|
int info = wk_init_info[id - FIRST_WKID];
|
|
int sid = (info >> CEIL_LG_OPTION_LIMIT);
|
|
int opt = (info & right_n_bits(CEIL_LG_OPTION_LIMIT));
|
|
|
|
initialize_wk_klass((WKID)id, opt, CHECK);
|
|
}
|
|
|
|
// move the starting value forward to the limit:
|
|
start_id = limit_id;
|
|
}
|
|
|
|
void SystemDictionary::initialize_preloaded_classes(TRAPS) {
|
|
assert(WK_KLASS(Object_klass) == NULL, "preloaded classes should only be initialized once");
|
|
|
|
// Create the ModuleEntry for java.base. This call needs to be done here,
|
|
// after vmSymbols::initialize() is called but before any classes are pre-loaded.
|
|
ClassLoader::create_javabase();
|
|
|
|
// Preload commonly used klasses
|
|
WKID scan = FIRST_WKID;
|
|
// first do Object, then String, Class
|
|
if (UseSharedSpaces) {
|
|
initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Object_klass), scan, CHECK);
|
|
// Initialize the constant pool for the Object_class
|
|
InstanceKlass* ik = InstanceKlass::cast(Object_klass());
|
|
ik->constants()->restore_unshareable_info(CHECK);
|
|
initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
|
|
} else {
|
|
initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK);
|
|
}
|
|
|
|
// Calculate offsets for String and Class classes since they are loaded and
|
|
// can be used after this point.
|
|
java_lang_String::compute_offsets();
|
|
java_lang_Class::compute_offsets();
|
|
|
|
// Fixup mirrors for classes loaded before java.lang.Class.
|
|
// These calls iterate over the objects currently in the perm gen
|
|
// so calling them at this point is matters (not before when there
|
|
// are fewer objects and not later after there are more objects
|
|
// in the perm gen.
|
|
Universe::initialize_basic_type_mirrors(CHECK);
|
|
Universe::fixup_mirrors(CHECK);
|
|
|
|
// do a bunch more:
|
|
initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Reference_klass), scan, CHECK);
|
|
|
|
// Preload ref klasses and set reference types
|
|
InstanceKlass::cast(WK_KLASS(Reference_klass))->set_reference_type(REF_OTHER);
|
|
InstanceRefKlass::update_nonstatic_oop_maps(WK_KLASS(Reference_klass));
|
|
|
|
initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(PhantomReference_klass), scan, CHECK);
|
|
InstanceKlass::cast(WK_KLASS(SoftReference_klass))->set_reference_type(REF_SOFT);
|
|
InstanceKlass::cast(WK_KLASS(WeakReference_klass))->set_reference_type(REF_WEAK);
|
|
InstanceKlass::cast(WK_KLASS(FinalReference_klass))->set_reference_type(REF_FINAL);
|
|
InstanceKlass::cast(WK_KLASS(PhantomReference_klass))->set_reference_type(REF_PHANTOM);
|
|
|
|
// JSR 292 classes
|
|
WKID jsr292_group_start = WK_KLASS_ENUM_NAME(MethodHandle_klass);
|
|
WKID jsr292_group_end = WK_KLASS_ENUM_NAME(VolatileCallSite_klass);
|
|
initialize_wk_klasses_until(jsr292_group_start, scan, CHECK);
|
|
initialize_wk_klasses_through(jsr292_group_end, scan, CHECK);
|
|
initialize_wk_klasses_until(NOT_JVMCI(WKID_LIMIT) JVMCI_ONLY(FIRST_JVMCI_WKID), scan, CHECK);
|
|
|
|
_box_klasses[T_BOOLEAN] = WK_KLASS(Boolean_klass);
|
|
_box_klasses[T_CHAR] = WK_KLASS(Character_klass);
|
|
_box_klasses[T_FLOAT] = WK_KLASS(Float_klass);
|
|
_box_klasses[T_DOUBLE] = WK_KLASS(Double_klass);
|
|
_box_klasses[T_BYTE] = WK_KLASS(Byte_klass);
|
|
_box_klasses[T_SHORT] = WK_KLASS(Short_klass);
|
|
_box_klasses[T_INT] = WK_KLASS(Integer_klass);
|
|
_box_klasses[T_LONG] = WK_KLASS(Long_klass);
|
|
//_box_klasses[T_OBJECT] = WK_KLASS(object_klass);
|
|
//_box_klasses[T_ARRAY] = WK_KLASS(object_klass);
|
|
|
|
{ // Compute whether we should use loadClass or loadClassInternal when loading classes.
|
|
Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::loadClassInternal_name(), vmSymbols::string_class_signature());
|
|
_has_loadClassInternal = (method != NULL);
|
|
}
|
|
{ // Compute whether we should use checkPackageAccess or NOT
|
|
Method* method = InstanceKlass::cast(ClassLoader_klass())->find_method(vmSymbols::checkPackageAccess_name(), vmSymbols::class_protectiondomain_signature());
|
|
_has_checkPackageAccess = (method != NULL);
|
|
}
|
|
}
|
|
|
|
// Tells if a given klass is a box (wrapper class, such as java.lang.Integer).
|
|
// If so, returns the basic type it holds. If not, returns T_OBJECT.
|
|
BasicType SystemDictionary::box_klass_type(Klass* k) {
|
|
assert(k != NULL, "");
|
|
for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
|
|
if (_box_klasses[i] == k)
|
|
return (BasicType)i;
|
|
}
|
|
return T_OBJECT;
|
|
}
|
|
|
|
// Constraints on class loaders. The details of the algorithm can be
|
|
// found in the OOPSLA'98 paper "Dynamic Class Loading in the Java
|
|
// Virtual Machine" by Sheng Liang and Gilad Bracha. The basic idea is
|
|
// that the system dictionary needs to maintain a set of contraints that
|
|
// must be satisfied by all classes in the dictionary.
|
|
// if defining is true, then LinkageError if already in systemDictionary
|
|
// if initiating loader, then ok if InstanceKlass matches existing entry
|
|
|
|
void SystemDictionary::check_constraints(int d_index, unsigned int d_hash,
|
|
instanceKlassHandle k,
|
|
Handle class_loader, bool defining,
|
|
TRAPS) {
|
|
const char *linkage_error1 = NULL;
|
|
const char *linkage_error2 = NULL;
|
|
{
|
|
Symbol* name = k->name();
|
|
ClassLoaderData *loader_data = class_loader_data(class_loader);
|
|
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
|
|
Klass* check = find_class(d_index, d_hash, name, loader_data);
|
|
if (check != (Klass*)NULL) {
|
|
// if different InstanceKlass - duplicate class definition,
|
|
// else - ok, class loaded by a different thread in parallel,
|
|
// we should only have found it if it was done loading and ok to use
|
|
// system dictionary only holds instance classes, placeholders
|
|
// also holds array classes
|
|
|
|
assert(check->is_instance_klass(), "noninstance in systemdictionary");
|
|
if ((defining == true) || (k() != check)) {
|
|
linkage_error1 = "loader (instance of ";
|
|
linkage_error2 = "): attempted duplicate class definition for name: \"";
|
|
} else {
|
|
return;
|
|
}
|
|
}
|
|
|
|
#ifdef ASSERT
|
|
Symbol* ph_check = find_placeholder(name, loader_data);
|
|
assert(ph_check == NULL || ph_check == name, "invalid symbol");
|
|
#endif
|
|
|
|
if (linkage_error1 == NULL) {
|
|
if (constraints()->check_or_update(k, class_loader, name) == false) {
|
|
linkage_error1 = "loader constraint violation: loader (instance of ";
|
|
linkage_error2 = ") previously initiated loading for a different type with name \"";
|
|
}
|
|
}
|
|
}
|
|
|
|
// Throw error now if needed (cannot throw while holding
|
|
// SystemDictionary_lock because of rank ordering)
|
|
|
|
if (linkage_error1) {
|
|
ResourceMark rm(THREAD);
|
|
const char* class_loader_name = loader_name(class_loader());
|
|
char* type_name = k->name()->as_C_string();
|
|
size_t buflen = strlen(linkage_error1) + strlen(class_loader_name) +
|
|
strlen(linkage_error2) + strlen(type_name) + 2; // +2 for '"' and null byte.
|
|
char* buf = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char, buflen);
|
|
jio_snprintf(buf, buflen, "%s%s%s%s\"", linkage_error1, class_loader_name, linkage_error2, type_name);
|
|
THROW_MSG(vmSymbols::java_lang_LinkageError(), buf);
|
|
}
|
|
}
|
|
|
|
|
|
// Update system dictionary - done after check_constraint and add_to_hierachy
|
|
// have been called.
|
|
void SystemDictionary::update_dictionary(int d_index, unsigned int d_hash,
|
|
int p_index, unsigned int p_hash,
|
|
instanceKlassHandle k,
|
|
Handle class_loader,
|
|
TRAPS) {
|
|
// Compile_lock prevents systemDictionary updates during compilations
|
|
assert_locked_or_safepoint(Compile_lock);
|
|
Symbol* name = k->name();
|
|
ClassLoaderData *loader_data = class_loader_data(class_loader);
|
|
|
|
{
|
|
MutexLocker mu1(SystemDictionary_lock, THREAD);
|
|
|
|
// See whether biased locking is enabled and if so set it for this
|
|
// klass.
|
|
// Note that this must be done past the last potential blocking
|
|
// point / safepoint. We enable biased locking lazily using a
|
|
// VM_Operation to iterate the SystemDictionary and installing the
|
|
// biasable mark word into each InstanceKlass's prototype header.
|
|
// To avoid race conditions where we accidentally miss enabling the
|
|
// optimization for one class in the process of being added to the
|
|
// dictionary, we must not safepoint after the test of
|
|
// BiasedLocking::enabled().
|
|
if (UseBiasedLocking && BiasedLocking::enabled()) {
|
|
// Set biased locking bit for all loaded classes; it will be
|
|
// cleared if revocation occurs too often for this type
|
|
// NOTE that we must only do this when the class is initally
|
|
// defined, not each time it is referenced from a new class loader
|
|
if (k->class_loader() == class_loader()) {
|
|
k->set_prototype_header(markOopDesc::biased_locking_prototype());
|
|
}
|
|
}
|
|
|
|
// Make a new system dictionary entry.
|
|
Klass* sd_check = find_class(d_index, d_hash, name, loader_data);
|
|
if (sd_check == NULL) {
|
|
dictionary()->add_klass(name, loader_data, k);
|
|
notice_modification();
|
|
}
|
|
#ifdef ASSERT
|
|
sd_check = find_class(d_index, d_hash, name, loader_data);
|
|
assert (sd_check != NULL, "should have entry in system dictionary");
|
|
// Note: there may be a placeholder entry: for circularity testing
|
|
// or for parallel defines
|
|
#endif
|
|
SystemDictionary_lock->notify_all();
|
|
}
|
|
}
|
|
|
|
|
|
// Try to find a class name using the loader constraints. The
|
|
// loader constraints might know about a class that isn't fully loaded
|
|
// yet and these will be ignored.
|
|
Klass* SystemDictionary::find_constrained_instance_or_array_klass(
|
|
Symbol* class_name, Handle class_loader, TRAPS) {
|
|
|
|
// First see if it has been loaded directly.
|
|
// Force the protection domain to be null. (This removes protection checks.)
|
|
Handle no_protection_domain;
|
|
Klass* klass = find_instance_or_array_klass(class_name, class_loader,
|
|
no_protection_domain, CHECK_NULL);
|
|
if (klass != NULL)
|
|
return klass;
|
|
|
|
// Now look to see if it has been loaded elsewhere, and is subject to
|
|
// a loader constraint that would require this loader to return the
|
|
// klass that is already loaded.
|
|
if (FieldType::is_array(class_name)) {
|
|
// For array classes, their Klass*s are not kept in the
|
|
// constraint table. The element Klass*s are.
|
|
FieldArrayInfo fd;
|
|
BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(NULL));
|
|
if (t != T_OBJECT) {
|
|
klass = Universe::typeArrayKlassObj(t);
|
|
} else {
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
klass = constraints()->find_constrained_klass(fd.object_key(), class_loader);
|
|
}
|
|
// If element class already loaded, allocate array klass
|
|
if (klass != NULL) {
|
|
klass = klass->array_klass_or_null(fd.dimension());
|
|
}
|
|
} else {
|
|
MutexLocker mu(SystemDictionary_lock, THREAD);
|
|
// Non-array classes are easy: simply check the constraint table.
|
|
klass = constraints()->find_constrained_klass(class_name, class_loader);
|
|
}
|
|
|
|
return klass;
|
|
}
|
|
|
|
|
|
bool SystemDictionary::add_loader_constraint(Symbol* class_name,
|
|
Handle class_loader1,
|
|
Handle class_loader2,
|
|
Thread* THREAD) {
|
|
ClassLoaderData* loader_data1 = class_loader_data(class_loader1);
|
|
ClassLoaderData* loader_data2 = class_loader_data(class_loader2);
|
|
|
|
Symbol* constraint_name = NULL;
|
|
if (!FieldType::is_array(class_name)) {
|
|
constraint_name = class_name;
|
|
} else {
|
|
// For array classes, their Klass*s are not kept in the
|
|
// constraint table. The element classes are.
|
|
FieldArrayInfo fd;
|
|
BasicType t = FieldType::get_array_info(class_name, fd, CHECK_(false));
|
|
// primitive types always pass
|
|
if (t != T_OBJECT) {
|
|
return true;
|
|
} else {
|
|
constraint_name = fd.object_key();
|
|
}
|
|
}
|
|
unsigned int d_hash1 = dictionary()->compute_hash(constraint_name, loader_data1);
|
|
int d_index1 = dictionary()->hash_to_index(d_hash1);
|
|
|
|
unsigned int d_hash2 = dictionary()->compute_hash(constraint_name, loader_data2);
|
|
int d_index2 = dictionary()->hash_to_index(d_hash2);
|
|
{
|
|
MutexLocker mu_s(SystemDictionary_lock, THREAD);
|
|
|
|
// Better never do a GC while we're holding these oops
|
|
NoSafepointVerifier nosafepoint;
|
|
|
|
Klass* klass1 = find_class(d_index1, d_hash1, constraint_name, loader_data1);
|
|
Klass* klass2 = find_class(d_index2, d_hash2, constraint_name, loader_data2);
|
|
return constraints()->add_entry(constraint_name, klass1, class_loader1,
|
|
klass2, class_loader2);
|
|
}
|
|
}
|
|
|
|
// Add entry to resolution error table to record the error when the first
|
|
// attempt to resolve a reference to a class has failed.
|
|
void SystemDictionary::add_resolution_error(const constantPoolHandle& pool, int which,
|
|
Symbol* error, Symbol* message) {
|
|
unsigned int hash = resolution_errors()->compute_hash(pool, which);
|
|
int index = resolution_errors()->hash_to_index(hash);
|
|
{
|
|
MutexLocker ml(SystemDictionary_lock, Thread::current());
|
|
resolution_errors()->add_entry(index, hash, pool, which, error, message);
|
|
}
|
|
}
|
|
|
|
// Delete a resolution error for RedefineClasses for a constant pool is going away
|
|
void SystemDictionary::delete_resolution_error(ConstantPool* pool) {
|
|
resolution_errors()->delete_entry(pool);
|
|
}
|
|
|
|
// Lookup resolution error table. Returns error if found, otherwise NULL.
|
|
Symbol* SystemDictionary::find_resolution_error(const constantPoolHandle& pool, int which,
|
|
Symbol** message) {
|
|
unsigned int hash = resolution_errors()->compute_hash(pool, which);
|
|
int index = resolution_errors()->hash_to_index(hash);
|
|
{
|
|
MutexLocker ml(SystemDictionary_lock, Thread::current());
|
|
ResolutionErrorEntry* entry = resolution_errors()->find_entry(index, hash, pool, which);
|
|
if (entry != NULL) {
|
|
*message = entry->message();
|
|
return entry->error();
|
|
} else {
|
|
return NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
// Signature constraints ensure that callers and callees agree about
|
|
// the meaning of type names in their signatures. This routine is the
|
|
// intake for constraints. It collects them from several places:
|
|
//
|
|
// * LinkResolver::resolve_method (if check_access is true) requires
|
|
// that the resolving class (the caller) and the defining class of
|
|
// the resolved method (the callee) agree on each type in the
|
|
// method's signature.
|
|
//
|
|
// * LinkResolver::resolve_interface_method performs exactly the same
|
|
// checks.
|
|
//
|
|
// * LinkResolver::resolve_field requires that the constant pool
|
|
// attempting to link to a field agree with the field's defining
|
|
// class about the type of the field signature.
|
|
//
|
|
// * klassVtable::initialize_vtable requires that, when a class
|
|
// overrides a vtable entry allocated by a superclass, that the
|
|
// overriding method (i.e., the callee) agree with the superclass
|
|
// on each type in the method's signature.
|
|
//
|
|
// * klassItable::initialize_itable requires that, when a class fills
|
|
// in its itables, for each non-abstract method installed in an
|
|
// itable, the method (i.e., the callee) agree with the interface
|
|
// on each type in the method's signature.
|
|
//
|
|
// All those methods have a boolean (check_access, checkconstraints)
|
|
// which turns off the checks. This is used from specialized contexts
|
|
// such as bootstrapping, dumping, and debugging.
|
|
//
|
|
// No direct constraint is placed between the class and its
|
|
// supertypes. Constraints are only placed along linked relations
|
|
// between callers and callees. When a method overrides or implements
|
|
// an abstract method in a supertype (superclass or interface), the
|
|
// constraints are placed as if the supertype were the caller to the
|
|
// overriding method. (This works well, since callers to the
|
|
// supertype have already established agreement between themselves and
|
|
// the supertype.) As a result of all this, a class can disagree with
|
|
// its supertype about the meaning of a type name, as long as that
|
|
// class neither calls a relevant method of the supertype, nor is
|
|
// called (perhaps via an override) from the supertype.
|
|
//
|
|
//
|
|
// SystemDictionary::check_signature_loaders(sig, l1, l2)
|
|
//
|
|
// Make sure all class components (including arrays) in the given
|
|
// signature will be resolved to the same class in both loaders.
|
|
// Returns the name of the type that failed a loader constraint check, or
|
|
// NULL if no constraint failed. No exception except OOME is thrown.
|
|
// Arrays are not added to the loader constraint table, their elements are.
|
|
Symbol* SystemDictionary::check_signature_loaders(Symbol* signature,
|
|
Handle loader1, Handle loader2,
|
|
bool is_method, TRAPS) {
|
|
// Nothing to do if loaders are the same.
|
|
if (loader1() == loader2()) {
|
|
return NULL;
|
|
}
|
|
|
|
SignatureStream sig_strm(signature, is_method);
|
|
while (!sig_strm.is_done()) {
|
|
if (sig_strm.is_object()) {
|
|
Symbol* sig = sig_strm.as_symbol(CHECK_NULL);
|
|
if (!add_loader_constraint(sig, loader1, loader2, THREAD)) {
|
|
return sig;
|
|
}
|
|
}
|
|
sig_strm.next();
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
|
|
methodHandle SystemDictionary::find_method_handle_intrinsic(vmIntrinsics::ID iid,
|
|
Symbol* signature,
|
|
TRAPS) {
|
|
methodHandle empty;
|
|
assert(MethodHandles::is_signature_polymorphic(iid) &&
|
|
MethodHandles::is_signature_polymorphic_intrinsic(iid) &&
|
|
iid != vmIntrinsics::_invokeGeneric,
|
|
"must be a known MH intrinsic iid=%d: %s", iid, vmIntrinsics::name_at(iid));
|
|
|
|
unsigned int hash = invoke_method_table()->compute_hash(signature, iid);
|
|
int index = invoke_method_table()->hash_to_index(hash);
|
|
SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, iid);
|
|
methodHandle m;
|
|
if (spe == NULL || spe->method() == NULL) {
|
|
spe = NULL;
|
|
// Must create lots of stuff here, but outside of the SystemDictionary lock.
|
|
m = Method::make_method_handle_intrinsic(iid, signature, CHECK_(empty));
|
|
if (!Arguments::is_interpreter_only()) {
|
|
// Generate a compiled form of the MH intrinsic.
|
|
AdapterHandlerLibrary::create_native_wrapper(m);
|
|
// Check if have the compiled code.
|
|
if (!m->has_compiled_code()) {
|
|
THROW_MSG_(vmSymbols::java_lang_VirtualMachineError(),
|
|
"Out of space in CodeCache for method handle intrinsic", empty);
|
|
}
|
|
}
|
|
// Now grab the lock. We might have to throw away the new method,
|
|
// if a racing thread has managed to install one at the same time.
|
|
{
|
|
MutexLocker ml(SystemDictionary_lock, THREAD);
|
|
spe = invoke_method_table()->find_entry(index, hash, signature, iid);
|
|
if (spe == NULL)
|
|
spe = invoke_method_table()->add_entry(index, hash, signature, iid);
|
|
if (spe->method() == NULL)
|
|
spe->set_method(m());
|
|
}
|
|
}
|
|
|
|
assert(spe != NULL && spe->method() != NULL, "");
|
|
assert(Arguments::is_interpreter_only() || (spe->method()->has_compiled_code() &&
|
|
spe->method()->code()->entry_point() == spe->method()->from_compiled_entry()),
|
|
"MH intrinsic invariant");
|
|
return spe->method();
|
|
}
|
|
|
|
// Helper for unpacking the return value from linkMethod and linkCallSite.
|
|
static methodHandle unpack_method_and_appendix(Handle mname,
|
|
KlassHandle accessing_klass,
|
|
objArrayHandle appendix_box,
|
|
Handle* appendix_result,
|
|
TRAPS) {
|
|
methodHandle empty;
|
|
if (mname.not_null()) {
|
|
Metadata* vmtarget = java_lang_invoke_MemberName::vmtarget(mname());
|
|
if (vmtarget != NULL && vmtarget->is_method()) {
|
|
Method* m = (Method*)vmtarget;
|
|
oop appendix = appendix_box->obj_at(0);
|
|
if (TraceMethodHandles) {
|
|
#ifndef PRODUCT
|
|
ttyLocker ttyl;
|
|
tty->print("Linked method=" INTPTR_FORMAT ": ", p2i(m));
|
|
m->print();
|
|
if (appendix != NULL) { tty->print("appendix = "); appendix->print(); }
|
|
tty->cr();
|
|
#endif //PRODUCT
|
|
}
|
|
(*appendix_result) = Handle(THREAD, appendix);
|
|
// the target is stored in the cpCache and if a reference to this
|
|
// MethodName is dropped we need a way to make sure the
|
|
// class_loader containing this method is kept alive.
|
|
// FIXME: the appendix might also preserve this dependency.
|
|
ClassLoaderData* this_key = InstanceKlass::cast(accessing_klass())->class_loader_data();
|
|
this_key->record_dependency(m->method_holder(), CHECK_NULL); // Can throw OOM
|
|
return methodHandle(THREAD, m);
|
|
}
|
|
}
|
|
THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad value from MethodHandleNatives", empty);
|
|
return empty;
|
|
}
|
|
|
|
methodHandle SystemDictionary::find_method_handle_invoker(KlassHandle klass,
|
|
Symbol* name,
|
|
Symbol* signature,
|
|
KlassHandle accessing_klass,
|
|
Handle *appendix_result,
|
|
Handle *method_type_result,
|
|
TRAPS) {
|
|
methodHandle empty;
|
|
assert(THREAD->can_call_java() ,"");
|
|
Handle method_type =
|
|
SystemDictionary::find_method_handle_type(signature, accessing_klass, CHECK_(empty));
|
|
|
|
int ref_kind = JVM_REF_invokeVirtual;
|
|
Handle name_str = StringTable::intern(name, CHECK_(empty));
|
|
objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty));
|
|
assert(appendix_box->obj_at(0) == NULL, "");
|
|
|
|
// This should not happen. JDK code should take care of that.
|
|
if (accessing_klass.is_null() || method_type.is_null()) {
|
|
THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokehandle", empty);
|
|
}
|
|
|
|
// call java.lang.invoke.MethodHandleNatives::linkMethod(... String, MethodType) -> MemberName
|
|
JavaCallArguments args;
|
|
args.push_oop(accessing_klass()->java_mirror());
|
|
args.push_int(ref_kind);
|
|
args.push_oop(klass()->java_mirror());
|
|
args.push_oop(name_str());
|
|
args.push_oop(method_type());
|
|
args.push_oop(appendix_box());
|
|
JavaValue result(T_OBJECT);
|
|
JavaCalls::call_static(&result,
|
|
SystemDictionary::MethodHandleNatives_klass(),
|
|
vmSymbols::linkMethod_name(),
|
|
vmSymbols::linkMethod_signature(),
|
|
&args, CHECK_(empty));
|
|
Handle mname(THREAD, (oop) result.get_jobject());
|
|
(*method_type_result) = method_type;
|
|
return unpack_method_and_appendix(mname, accessing_klass, appendix_box, appendix_result, THREAD);
|
|
}
|
|
|
|
// Decide if we can globally cache a lookup of this class, to be returned to any client that asks.
|
|
// We must ensure that all class loaders everywhere will reach this class, for any client.
|
|
// This is a safe bet for public classes in java.lang, such as Object and String.
|
|
// We also include public classes in java.lang.invoke, because they appear frequently in system-level method types.
|
|
// Out of an abundance of caution, we do not include any other classes, not even for packages like java.util.
|
|
static bool is_always_visible_class(oop mirror) {
|
|
Klass* klass = java_lang_Class::as_Klass(mirror);
|
|
if (klass->is_objArray_klass()) {
|
|
klass = ObjArrayKlass::cast(klass)->bottom_klass(); // check element type
|
|
}
|
|
if (klass->is_typeArray_klass()) {
|
|
return true; // primitive array
|
|
}
|
|
assert(klass->is_instance_klass(), "%s", klass->external_name());
|
|
return klass->is_public() &&
|
|
(InstanceKlass::cast(klass)->is_same_class_package(SystemDictionary::Object_klass()) || // java.lang
|
|
InstanceKlass::cast(klass)->is_same_class_package(SystemDictionary::MethodHandle_klass())); // java.lang.invoke
|
|
}
|
|
|
|
// Ask Java code to find or construct a java.lang.invoke.MethodType for the given
|
|
// signature, as interpreted relative to the given class loader.
|
|
// Because of class loader constraints, all method handle usage must be
|
|
// consistent with this loader.
|
|
Handle SystemDictionary::find_method_handle_type(Symbol* signature,
|
|
KlassHandle accessing_klass,
|
|
TRAPS) {
|
|
Handle empty;
|
|
vmIntrinsics::ID null_iid = vmIntrinsics::_none; // distinct from all method handle invoker intrinsics
|
|
unsigned int hash = invoke_method_table()->compute_hash(signature, null_iid);
|
|
int index = invoke_method_table()->hash_to_index(hash);
|
|
SymbolPropertyEntry* spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
|
|
if (spe != NULL && spe->method_type() != NULL) {
|
|
assert(java_lang_invoke_MethodType::is_instance(spe->method_type()), "");
|
|
return Handle(THREAD, spe->method_type());
|
|
} else if (!THREAD->can_call_java()) {
|
|
warning("SystemDictionary::find_method_handle_type called from compiler thread"); // FIXME
|
|
return Handle(); // do not attempt from within compiler, unless it was cached
|
|
}
|
|
|
|
Handle class_loader, protection_domain;
|
|
if (accessing_klass.not_null()) {
|
|
class_loader = Handle(THREAD, InstanceKlass::cast(accessing_klass())->class_loader());
|
|
protection_domain = Handle(THREAD, InstanceKlass::cast(accessing_klass())->protection_domain());
|
|
}
|
|
bool can_be_cached = true;
|
|
int npts = ArgumentCount(signature).size();
|
|
objArrayHandle pts = oopFactory::new_objArray(SystemDictionary::Class_klass(), npts, CHECK_(empty));
|
|
int arg = 0;
|
|
Handle rt; // the return type from the signature
|
|
ResourceMark rm(THREAD);
|
|
for (SignatureStream ss(signature); !ss.is_done(); ss.next()) {
|
|
oop mirror = NULL;
|
|
if (can_be_cached) {
|
|
// Use neutral class loader to lookup candidate classes to be placed in the cache.
|
|
mirror = ss.as_java_mirror(Handle(), Handle(),
|
|
SignatureStream::ReturnNull, CHECK_(empty));
|
|
if (mirror == NULL || (ss.is_object() && !is_always_visible_class(mirror))) {
|
|
// Fall back to accessing_klass context.
|
|
can_be_cached = false;
|
|
}
|
|
}
|
|
if (!can_be_cached) {
|
|
// Resolve, throwing a real error if it doesn't work.
|
|
mirror = ss.as_java_mirror(class_loader, protection_domain,
|
|
SignatureStream::NCDFError, CHECK_(empty));
|
|
}
|
|
assert(!oopDesc::is_null(mirror), "%s", ss.as_symbol(THREAD)->as_C_string());
|
|
if (ss.at_return_type())
|
|
rt = Handle(THREAD, mirror);
|
|
else
|
|
pts->obj_at_put(arg++, mirror);
|
|
|
|
// Check accessibility.
|
|
if (ss.is_object() && accessing_klass.not_null()) {
|
|
Klass* sel_klass = java_lang_Class::as_Klass(mirror);
|
|
mirror = NULL; // safety
|
|
// Emulate ConstantPool::verify_constant_pool_resolve.
|
|
if (sel_klass->is_objArray_klass())
|
|
sel_klass = ObjArrayKlass::cast(sel_klass)->bottom_klass();
|
|
if (sel_klass->is_instance_klass()) {
|
|
KlassHandle sel_kh(THREAD, sel_klass);
|
|
LinkResolver::check_klass_accessability(accessing_klass, sel_kh, CHECK_(empty));
|
|
}
|
|
}
|
|
}
|
|
assert(arg == npts, "");
|
|
|
|
// call java.lang.invoke.MethodHandleNatives::findMethodType(Class rt, Class[] pts) -> MethodType
|
|
JavaCallArguments args(Handle(THREAD, rt()));
|
|
args.push_oop(pts());
|
|
JavaValue result(T_OBJECT);
|
|
JavaCalls::call_static(&result,
|
|
SystemDictionary::MethodHandleNatives_klass(),
|
|
vmSymbols::findMethodHandleType_name(),
|
|
vmSymbols::findMethodHandleType_signature(),
|
|
&args, CHECK_(empty));
|
|
Handle method_type(THREAD, (oop) result.get_jobject());
|
|
|
|
if (can_be_cached) {
|
|
// We can cache this MethodType inside the JVM.
|
|
MutexLocker ml(SystemDictionary_lock, THREAD);
|
|
spe = invoke_method_table()->find_entry(index, hash, signature, null_iid);
|
|
if (spe == NULL)
|
|
spe = invoke_method_table()->add_entry(index, hash, signature, null_iid);
|
|
if (spe->method_type() == NULL) {
|
|
spe->set_method_type(method_type());
|
|
}
|
|
}
|
|
|
|
// report back to the caller with the MethodType
|
|
return method_type;
|
|
}
|
|
|
|
// Ask Java code to find or construct a method handle constant.
|
|
Handle SystemDictionary::link_method_handle_constant(KlassHandle caller,
|
|
int ref_kind, //e.g., JVM_REF_invokeVirtual
|
|
KlassHandle callee,
|
|
Symbol* name_sym,
|
|
Symbol* signature,
|
|
TRAPS) {
|
|
Handle empty;
|
|
Handle name = java_lang_String::create_from_symbol(name_sym, CHECK_(empty));
|
|
Handle type;
|
|
if (signature->utf8_length() > 0 && signature->byte_at(0) == '(') {
|
|
type = find_method_handle_type(signature, caller, CHECK_(empty));
|
|
} else if (caller.is_null()) {
|
|
// This should not happen. JDK code should take care of that.
|
|
THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad MH constant", empty);
|
|
} else {
|
|
ResourceMark rm(THREAD);
|
|
SignatureStream ss(signature, false);
|
|
if (!ss.is_done()) {
|
|
oop mirror = ss.as_java_mirror(caller->class_loader(), caller->protection_domain(),
|
|
SignatureStream::NCDFError, CHECK_(empty));
|
|
type = Handle(THREAD, mirror);
|
|
ss.next();
|
|
if (!ss.is_done()) type = Handle(); // error!
|
|
}
|
|
}
|
|
if (type.is_null()) {
|
|
THROW_MSG_(vmSymbols::java_lang_LinkageError(), "bad signature", empty);
|
|
}
|
|
|
|
// call java.lang.invoke.MethodHandleNatives::linkMethodHandleConstant(Class caller, int refKind, Class callee, String name, Object type) -> MethodHandle
|
|
JavaCallArguments args;
|
|
args.push_oop(caller->java_mirror()); // the referring class
|
|
args.push_int(ref_kind);
|
|
args.push_oop(callee->java_mirror()); // the target class
|
|
args.push_oop(name());
|
|
args.push_oop(type());
|
|
JavaValue result(T_OBJECT);
|
|
JavaCalls::call_static(&result,
|
|
SystemDictionary::MethodHandleNatives_klass(),
|
|
vmSymbols::linkMethodHandleConstant_name(),
|
|
vmSymbols::linkMethodHandleConstant_signature(),
|
|
&args, CHECK_(empty));
|
|
return Handle(THREAD, (oop) result.get_jobject());
|
|
}
|
|
|
|
// Ask Java code to find or construct a java.lang.invoke.CallSite for the given
|
|
// name and signature, as interpreted relative to the given class loader.
|
|
methodHandle SystemDictionary::find_dynamic_call_site_invoker(KlassHandle caller,
|
|
Handle bootstrap_specifier,
|
|
Symbol* name,
|
|
Symbol* type,
|
|
Handle *appendix_result,
|
|
Handle *method_type_result,
|
|
TRAPS) {
|
|
methodHandle empty;
|
|
Handle bsm, info;
|
|
if (java_lang_invoke_MethodHandle::is_instance(bootstrap_specifier())) {
|
|
bsm = bootstrap_specifier;
|
|
} else {
|
|
assert(bootstrap_specifier->is_objArray(), "");
|
|
objArrayHandle args(THREAD, (objArrayOop) bootstrap_specifier());
|
|
int len = args->length();
|
|
assert(len >= 1, "");
|
|
bsm = Handle(THREAD, args->obj_at(0));
|
|
if (len > 1) {
|
|
objArrayOop args1 = oopFactory::new_objArray(SystemDictionary::Object_klass(), len-1, CHECK_(empty));
|
|
for (int i = 1; i < len; i++)
|
|
args1->obj_at_put(i-1, args->obj_at(i));
|
|
info = Handle(THREAD, args1);
|
|
}
|
|
}
|
|
guarantee(java_lang_invoke_MethodHandle::is_instance(bsm()),
|
|
"caller must supply a valid BSM");
|
|
|
|
Handle method_name = java_lang_String::create_from_symbol(name, CHECK_(empty));
|
|
Handle method_type = find_method_handle_type(type, caller, CHECK_(empty));
|
|
|
|
// This should not happen. JDK code should take care of that.
|
|
if (caller.is_null() || method_type.is_null()) {
|
|
THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokedynamic", empty);
|
|
}
|
|
|
|
objArrayHandle appendix_box = oopFactory::new_objArray(SystemDictionary::Object_klass(), 1, CHECK_(empty));
|
|
assert(appendix_box->obj_at(0) == NULL, "");
|
|
|
|
// call java.lang.invoke.MethodHandleNatives::linkCallSite(caller, bsm, name, mtype, info, &appendix)
|
|
JavaCallArguments args;
|
|
args.push_oop(caller->java_mirror());
|
|
args.push_oop(bsm());
|
|
args.push_oop(method_name());
|
|
args.push_oop(method_type());
|
|
args.push_oop(info());
|
|
args.push_oop(appendix_box);
|
|
JavaValue result(T_OBJECT);
|
|
JavaCalls::call_static(&result,
|
|
SystemDictionary::MethodHandleNatives_klass(),
|
|
vmSymbols::linkCallSite_name(),
|
|
vmSymbols::linkCallSite_signature(),
|
|
&args, CHECK_(empty));
|
|
Handle mname(THREAD, (oop) result.get_jobject());
|
|
(*method_type_result) = method_type;
|
|
return unpack_method_and_appendix(mname, caller, appendix_box, appendix_result, THREAD);
|
|
}
|
|
|
|
// Since the identity hash code for symbols changes when the symbols are
|
|
// moved from the regular perm gen (hash in the mark word) to the shared
|
|
// spaces (hash is the address), the classes loaded into the dictionary
|
|
// may be in the wrong buckets.
|
|
|
|
void SystemDictionary::reorder_dictionary() {
|
|
dictionary()->reorder_dictionary();
|
|
}
|
|
|
|
|
|
void SystemDictionary::copy_buckets(char** top, char* end) {
|
|
dictionary()->copy_buckets(top, end);
|
|
}
|
|
|
|
|
|
void SystemDictionary::copy_table(char** top, char* end) {
|
|
dictionary()->copy_table(top, end);
|
|
}
|
|
|
|
|
|
void SystemDictionary::reverse() {
|
|
dictionary()->reverse();
|
|
}
|
|
|
|
int SystemDictionary::number_of_classes() {
|
|
return dictionary()->number_of_entries();
|
|
}
|
|
|
|
|
|
// ----------------------------------------------------------------------------
|
|
void SystemDictionary::print_shared(bool details) {
|
|
shared_dictionary()->print(details);
|
|
}
|
|
|
|
void SystemDictionary::print(bool details) {
|
|
dictionary()->print(details);
|
|
|
|
// Placeholders
|
|
GCMutexLocker mu(SystemDictionary_lock);
|
|
placeholders()->print();
|
|
|
|
// loader constraints - print under SD_lock
|
|
constraints()->print();
|
|
}
|
|
|
|
|
|
void SystemDictionary::verify() {
|
|
guarantee(dictionary() != NULL, "Verify of system dictionary failed");
|
|
guarantee(constraints() != NULL,
|
|
"Verify of loader constraints failed");
|
|
guarantee(dictionary()->number_of_entries() >= 0 &&
|
|
placeholders()->number_of_entries() >= 0,
|
|
"Verify of system dictionary failed");
|
|
|
|
// Verify dictionary
|
|
dictionary()->verify();
|
|
|
|
GCMutexLocker mu(SystemDictionary_lock);
|
|
placeholders()->verify();
|
|
|
|
// Verify constraint table
|
|
guarantee(constraints() != NULL, "Verify of loader constraints failed");
|
|
constraints()->verify(dictionary(), placeholders());
|
|
}
|
|
|
|
// caller needs ResourceMark
|
|
const char* SystemDictionary::loader_name(const oop loader) {
|
|
return ((loader) == NULL ? "<bootloader>" :
|
|
InstanceKlass::cast((loader)->klass())->name()->as_C_string());
|
|
}
|
|
|
|
// caller needs ResourceMark
|
|
const char* SystemDictionary::loader_name(const ClassLoaderData* loader_data) {
|
|
return (loader_data->class_loader() == NULL ? "<bootloader>" :
|
|
InstanceKlass::cast((loader_data->class_loader())->klass())->name()->as_C_string());
|
|
}
|