| /* |
| * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "aot/aotLoader.hpp" |
| #include "classfile/classFileParser.hpp" |
| #include "classfile/classFileStream.hpp" |
| #include "classfile/classLoader.hpp" |
| #include "classfile/classLoaderData.inline.hpp" |
| #include "classfile/classLoaderExt.hpp" |
| #include "classfile/dictionary.hpp" |
| #include "classfile/javaClasses.inline.hpp" |
| #include "classfile/klassFactory.hpp" |
| #include "classfile/loaderConstraints.hpp" |
| #include "classfile/packageEntry.hpp" |
| #include "classfile/placeholders.hpp" |
| #include "classfile/protectionDomainCache.hpp" |
| #include "classfile/resolutionErrors.hpp" |
| #include "classfile/stringTable.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "classfile/vmSymbols.hpp" |
| #include "code/codeCache.hpp" |
| #include "compiler/compileBroker.hpp" |
| #include "gc/shared/gcLocker.hpp" |
| #include "gc/shared/gcTraceTime.inline.hpp" |
| #include "interpreter/bytecodeStream.hpp" |
| #include "interpreter/interpreter.hpp" |
| #include "logging/log.hpp" |
| #include "logging/logStream.hpp" |
| #include "memory/filemap.hpp" |
| #include "memory/metaspaceClosure.hpp" |
| #include "memory/oopFactory.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "oops/instanceKlass.hpp" |
| #include "oops/instanceRefKlass.hpp" |
| #include "oops/klass.inline.hpp" |
| #include "oops/methodData.hpp" |
| #include "oops/objArrayKlass.hpp" |
| #include "oops/objArrayOop.inline.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "oops/symbol.hpp" |
| #include "oops/typeArrayKlass.hpp" |
| #include "prims/jvm.h" |
| #include "prims/jvmtiEnvBase.hpp" |
| #include "prims/resolvedMethodTable.hpp" |
| #include "prims/methodHandles.hpp" |
| #include "runtime/arguments.hpp" |
| #include "runtime/arguments_ext.hpp" |
| #include "runtime/biasedLocking.hpp" |
| #include "runtime/fieldType.hpp" |
| #include "runtime/handles.inline.hpp" |
| #include "runtime/java.hpp" |
| #include "runtime/javaCalls.hpp" |
| #include "runtime/mutexLocker.hpp" |
| #include "runtime/orderAccess.inline.hpp" |
| #include "runtime/signature.hpp" |
| #include "services/classLoadingService.hpp" |
| #include "services/diagnosticCommand.hpp" |
| #include "services/threadService.hpp" |
| #include "trace/tracing.hpp" |
| #include "utilities/macros.hpp" |
| #if INCLUDE_CDS |
| #include "classfile/sharedClassUtil.hpp" |
| #include "classfile/systemDictionaryShared.hpp" |
| #endif |
| #if INCLUDE_JVMCI |
| #include "jvmci/jvmciRuntime.hpp" |
| #endif |
| |
| PlaceholderTable* SystemDictionary::_placeholders = NULL; |
| Dictionary* SystemDictionary::_shared_dictionary = NULL; |
| LoaderConstraintTable* SystemDictionary::_loader_constraints = NULL; |
| ResolutionErrorTable* SystemDictionary::_resolution_errors = NULL; |
| SymbolPropertyTable* SystemDictionary::_invoke_method_table = NULL; |
| ProtectionDomainCacheTable* SystemDictionary::_pd_cache_table = NULL; |
| |
| int SystemDictionary::_number_of_modifications = 0; |
| oop SystemDictionary::_system_loader_lock_obj = NULL; |
| |
| InstanceKlass* SystemDictionary::_well_known_klasses[SystemDictionary::WKID_LIMIT] |
| = { NULL /*, NULL...*/ }; |
| |
| InstanceKlass* SystemDictionary::_box_klasses[T_VOID+1] = { NULL /*, NULL...*/ }; |
| |
| oop SystemDictionary::_java_system_loader = NULL; |
| |
| bool SystemDictionary::_has_loadClassInternal = false; |
| bool SystemDictionary::_has_checkPackageAccess = false; |
| |
| // lazily initialized klass variables |
| InstanceKlass* volatile SystemDictionary::_abstract_ownable_synchronizer_klass = NULL; |
| |
| // Default ProtectionDomainCacheSize value |
| |
| const int defaultProtectionDomainCacheSize = 1009; |
| |
| |
| // ---------------------------------------------------------------------------- |
| // Java-level SystemLoader |
| |
| oop SystemDictionary::java_system_loader() { |
| return _java_system_loader; |
| } |
| |
| void SystemDictionary::compute_java_system_loader(TRAPS) { |
| Klass* system_klass = WK_KLASS(ClassLoader_klass); |
| JavaValue result(T_OBJECT); |
| JavaCalls::call_static(&result, |
| WK_KLASS(ClassLoader_klass), |
| vmSymbols::getSystemClassLoader_name(), |
| vmSymbols::void_classloader_signature(), |
| CHECK); |
| |
| _java_system_loader = (oop)result.get_jobject(); |
| |
| CDS_ONLY(SystemDictionaryShared::initialize(CHECK);) |
| } |
| |
| |
| ClassLoaderData* SystemDictionary::register_loader(Handle class_loader, TRAPS) { |
| if (class_loader() == NULL) return ClassLoaderData::the_null_class_loader_data(); |
| return ClassLoaderDataGraph::find_or_create(class_loader, THREAD); |
| } |
| |
| // ---------------------------------------------------------------------------- |
| // Parallel class loading check |
| |
| bool SystemDictionary::is_parallelCapable(Handle class_loader) { |
| if (UnsyncloadClass || class_loader.is_null()) return true; |
| if (AlwaysLockClassLoader) return false; |
| return java_lang_ClassLoader::parallelCapable(class_loader()); |
| } |
| // ---------------------------------------------------------------------------- |
| // ParallelDefineClass flag does not apply to bootclass loader |
| bool SystemDictionary::is_parallelDefine(Handle class_loader) { |
| if (class_loader.is_null()) return false; |
| if (AllowParallelDefineClass && java_lang_ClassLoader::parallelCapable(class_loader())) { |
| return true; |
| } |
| return false; |
| } |
| |
| // Returns true if the passed class loader is the builtin application class loader |
| // or a custom system class loader. A customer system class loader can be |
| // specified via -Djava.system.class.loader. |
| bool SystemDictionary::is_system_class_loader(oop class_loader) { |
| if (class_loader == NULL) { |
| return false; |
| } |
| return (class_loader->klass() == SystemDictionary::jdk_internal_loader_ClassLoaders_AppClassLoader_klass() || |
| class_loader == _java_system_loader); |
| } |
| |
| // Returns true if the passed class loader is the platform class loader. |
| bool SystemDictionary::is_platform_class_loader(oop class_loader) { |
| if (class_loader == NULL) { |
| return false; |
| } |
| return (class_loader->klass() == SystemDictionary::jdk_internal_loader_ClassLoaders_PlatformClassLoader_klass()); |
| } |
| |
| // ---------------------------------------------------------------------------- |
| // Resolving of classes |
| |
| // Forwards to resolve_or_null |
| |
| Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, Handle class_loader, Handle protection_domain, bool throw_error, TRAPS) { |
| Klass* klass = resolve_or_null(class_name, class_loader, protection_domain, THREAD); |
| if (HAS_PENDING_EXCEPTION || klass == NULL) { |
| // can return a null klass |
| klass = handle_resolution_exception(class_name, throw_error, klass, THREAD); |
| } |
| return klass; |
| } |
| |
| Klass* SystemDictionary::handle_resolution_exception(Symbol* class_name, |
| bool throw_error, |
| Klass* klass, TRAPS) { |
| if (HAS_PENDING_EXCEPTION) { |
| // If we have a pending exception we forward it to the caller, unless throw_error is true, |
| // in which case we have to check whether the pending exception is a ClassNotFoundException, |
| // and if so convert it to a NoClassDefFoundError |
| // And chain the original ClassNotFoundException |
| if (throw_error && PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass())) { |
| ResourceMark rm(THREAD); |
| assert(klass == NULL, "Should not have result with exception pending"); |
| Handle e(THREAD, PENDING_EXCEPTION); |
| CLEAR_PENDING_EXCEPTION; |
| THROW_MSG_CAUSE_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string(), e); |
| } else { |
| return NULL; |
| } |
| } |
| // Class not found, throw appropriate error or exception depending on value of throw_error |
| if (klass == NULL) { |
| ResourceMark rm(THREAD); |
| if (throw_error) { |
| THROW_MSG_NULL(vmSymbols::java_lang_NoClassDefFoundError(), class_name->as_C_string()); |
| } else { |
| THROW_MSG_NULL(vmSymbols::java_lang_ClassNotFoundException(), class_name->as_C_string()); |
| } |
| } |
| return klass; |
| } |
| |
| |
| Klass* SystemDictionary::resolve_or_fail(Symbol* class_name, |
| bool throw_error, TRAPS) |
| { |
| return resolve_or_fail(class_name, Handle(), Handle(), throw_error, THREAD); |
| } |
| |
| |
| // Forwards to resolve_instance_class_or_null |
| |
| Klass* SystemDictionary::resolve_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS) { |
| assert(THREAD->can_call_java(), |
| "can not load classes with compiler thread: class=%s, classloader=%s", |
| class_name->as_C_string(), |
| class_loader.is_null() ? "null" : class_loader->klass()->name()->as_C_string()); |
| if (FieldType::is_array(class_name)) { |
| return resolve_array_class_or_null(class_name, class_loader, protection_domain, THREAD); |
| } else if (FieldType::is_obj(class_name)) { |
| ResourceMark rm(THREAD); |
| // Ignore wrapping L and ;. |
| TempNewSymbol name = SymbolTable::new_symbol(class_name->as_C_string() + 1, |
| class_name->utf8_length() - 2, CHECK_NULL); |
| return resolve_instance_class_or_null(name, class_loader, protection_domain, THREAD); |
| } else { |
| return resolve_instance_class_or_null(class_name, class_loader, protection_domain, THREAD); |
| } |
| } |
| |
| Klass* SystemDictionary::resolve_or_null(Symbol* class_name, TRAPS) { |
| return resolve_or_null(class_name, Handle(), Handle(), THREAD); |
| } |
| |
| // Forwards to resolve_instance_class_or_null |
| |
| Klass* SystemDictionary::resolve_array_class_or_null(Symbol* class_name, |
| Handle class_loader, |
| Handle protection_domain, |
| TRAPS) { |
| assert(FieldType::is_array(class_name), "must be array"); |
| Klass* k = NULL; |
| FieldArrayInfo fd; |
| // dimension and object_key in FieldArrayInfo are assigned as a side-effect |
| // of this call |
| BasicType t = FieldType::get_array_info(class_name, fd, CHECK_NULL); |
| if (t == T_OBJECT) { |
| // naked oop "k" is OK here -- we assign back into it |
| k = SystemDictionary::resolve_instance_class_or_null(fd.object_key(), |
| class_loader, |
| protection_domain, |
| CHECK_NULL); |
| if (k != NULL) { |
| k = k->array_klass(fd.dimension(), CHECK_NULL); |
| } |
| } else { |
| k = Universe::typeArrayKlassObj(t); |
| k = TypeArrayKlass::cast(k)->array_klass(fd.dimension(), CHECK_NULL); |
| } |
| return k; |
| } |
| |
| |
| // Must be called for any super-class or super-interface resolution |
| // during class definition to allow class circularity checking |
| // super-interface callers: |
| // parse_interfaces - for defineClass & jvmtiRedefineClasses |
| // super-class callers: |
| // ClassFileParser - for defineClass & jvmtiRedefineClasses |
| // load_shared_class - while loading a class from shared archive |
| // resolve_instance_class_or_null: |
| // via: handle_parallel_super_load |
| // when resolving a class that has an existing placeholder with |
| // a saved superclass [i.e. a defineClass is currently in progress] |
| // if another thread is trying to resolve the class, it must do |
| // super-class checks on its own thread to catch class circularity |
| // This last call is critical in class circularity checking for cases |
| // where classloading is delegated to different threads and the |
| // classloader lock is released. |
| // Take the case: Base->Super->Base |
| // 1. If thread T1 tries to do a defineClass of class Base |
| // resolve_super_or_fail creates placeholder: T1, Base (super Super) |
| // 2. resolve_instance_class_or_null does not find SD or placeholder for Super |
| // so it tries to load Super |
| // 3. If we load the class internally, or user classloader uses same thread |
| // loadClassFromxxx or defineClass via parseClassFile Super ... |
| // 3.1 resolve_super_or_fail creates placeholder: T1, Super (super Base) |
| // 3.3 resolve_instance_class_or_null Base, finds placeholder for Base |
| // 3.4 calls resolve_super_or_fail Base |
| // 3.5 finds T1,Base -> throws class circularity |
| //OR 4. If T2 tries to resolve Super via defineClass Super ... |
| // 4.1 resolve_super_or_fail creates placeholder: T2, Super (super Base) |
| // 4.2 resolve_instance_class_or_null Base, finds placeholder for Base (super Super) |
| // 4.3 calls resolve_super_or_fail Super in parallel on own thread T2 |
| // 4.4 finds T2, Super -> throws class circularity |
| // Must be called, even if superclass is null, since this is |
| // where the placeholder entry is created which claims this |
| // thread is loading this class/classloader. |
| // Be careful when modifying this code: once you have run |
| // placeholders()->find_and_add(PlaceholderTable::LOAD_SUPER), |
| // you need to find_and_remove it before returning. |
| // So be careful to not exit with a CHECK_ macro betweeen these calls. |
| Klass* SystemDictionary::resolve_super_or_fail(Symbol* child_name, |
| Symbol* class_name, |
| Handle class_loader, |
| Handle protection_domain, |
| bool is_superclass, |
| TRAPS) { |
| #if INCLUDE_CDS |
| if (DumpSharedSpaces) { |
| // Special processing for CDS dump time. |
| Klass* k = SystemDictionaryShared::dump_time_resolve_super_or_fail(child_name, |
| class_name, class_loader, protection_domain, is_superclass, CHECK_NULL); |
| if (k) { |
| return k; |
| } |
| } |
| #endif // INCLUDE_CDS |
| |
| // Double-check, if child class is already loaded, just return super-class,interface |
| // Don't add a placedholder if already loaded, i.e. already in appropriate class loader |
| // dictionary. |
| // Make sure there's a placeholder for the *child* before resolving. |
| // Used as a claim that this thread is currently loading superclass/classloader |
| // Used here for ClassCircularity checks and also for heap verification |
| // (every InstanceKlass needs to be in its class loader dictionary or have a placeholder). |
| // Must check ClassCircularity before checking if super class is already loaded. |
| // |
| // We might not already have a placeholder if this child_name was |
| // first seen via resolve_from_stream (jni_DefineClass or JVM_DefineClass); |
| // the name of the class might not be known until the stream is actually |
| // parsed. |
| // Bugs 4643874, 4715493 |
| |
| ClassLoaderData* loader_data = class_loader_data(class_loader); |
| Dictionary* dictionary = loader_data->dictionary(); |
| unsigned int d_hash = dictionary->compute_hash(child_name); |
| int d_index = dictionary->hash_to_index(d_hash); |
| unsigned int p_hash = placeholders()->compute_hash(child_name); |
| int p_index = placeholders()->hash_to_index(p_hash); |
| // can't throw error holding a lock |
| bool child_already_loaded = false; |
| bool throw_circularity_error = false; |
| { |
| MutexLocker mu(SystemDictionary_lock, THREAD); |
| Klass* childk = find_class(d_index, d_hash, child_name, dictionary); |
| Klass* quicksuperk; |
| // to support // loading: if child done loading, just return superclass |
| // if class_name, & class_loader don't match: |
| // if initial define, SD update will give LinkageError |
| // if redefine: compare_class_versions will give HIERARCHY_CHANGED |
| // so we don't throw an exception here. |
| // see: nsk redefclass014 & java.lang.instrument Instrument032 |
| if ((childk != NULL ) && (is_superclass) && |
| ((quicksuperk = childk->super()) != NULL) && |
| |
| ((quicksuperk->name() == class_name) && |
| (quicksuperk->class_loader() == class_loader()))) { |
| return quicksuperk; |
| } else { |
| PlaceholderEntry* probe = placeholders()->get_entry(p_index, p_hash, child_name, loader_data); |
| if (probe && probe->check_seen_thread(THREAD, PlaceholderTable::LOAD_SUPER)) { |
| throw_circularity_error = true; |
| } |
| } |
| if (!throw_circularity_error) { |
| // Be careful not to exit resolve_super |
| PlaceholderEntry* newprobe = placeholders()->find_and_add(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, class_name, THREAD); |
| } |
| } |
| if (throw_circularity_error) { |
| ResourceMark rm(THREAD); |
| THROW_MSG_NULL(vmSymbols::java_lang_ClassCircularityError(), child_name->as_C_string()); |
| } |
| |
| // java.lang.Object should have been found above |
| assert(class_name != NULL, "null super class for resolving"); |
| // Resolve the super class or interface, check results on return |
| Klass* superk = SystemDictionary::resolve_or_null(class_name, |
| class_loader, |
| protection_domain, |
| THREAD); |
| |
| // Clean up of placeholders moved so that each classloadAction registrar self-cleans up |
| // It is no longer necessary to keep the placeholder table alive until update_dictionary |
| // or error. GC used to walk the placeholder table as strong roots. |
| // The instanceKlass is kept alive because the class loader is on the stack, |
| // which keeps the loader_data alive, as well as all instanceKlasses in |
| // the loader_data. parseClassFile adds the instanceKlass to loader_data. |
| { |
| MutexLocker mu(SystemDictionary_lock, THREAD); |
| placeholders()->find_and_remove(p_index, p_hash, child_name, loader_data, PlaceholderTable::LOAD_SUPER, THREAD); |
| SystemDictionary_lock->notify_all(); |
| } |
| if (HAS_PENDING_EXCEPTION || superk == NULL) { |
| // can null superk |
| superk = handle_resolution_exception(class_name, true, superk, THREAD); |
| } |
| |
| return superk; |
| } |
| |
| void SystemDictionary::validate_protection_domain(InstanceKlass* klass, |
| Handle class_loader, |
| Handle protection_domain, |
| TRAPS) { |
| if(!has_checkPackageAccess()) return; |
| |
| // Now we have to call back to java to check if the initating class has access |
| JavaValue result(T_VOID); |
| LogTarget(Debug, protectiondomain) lt; |
| if (lt.is_enabled()) { |
| ResourceMark rm; |
| // Print out trace information |
| LogStream ls(lt); |
| ls.print_cr("Checking package access"); |
| ls.print("class loader: "); class_loader()->print_value_on(&ls); |
| ls.print(" protection domain: "); protection_domain()->print_value_on(&ls); |
| ls.print(" loading: "); klass->print_value_on(&ls); |
| ls.cr(); |
| } |
| |
| // This handle and the class_loader handle passed in keeps this class from |
| // being unloaded through several GC points. |
| // The class_loader handle passed in is the initiating loader. |
| Handle mirror(THREAD, klass->java_mirror()); |
| |
| InstanceKlass* system_loader = SystemDictionary::ClassLoader_klass(); |
| JavaCalls::call_special(&result, |
| class_loader, |
| system_loader, |
| vmSymbols::checkPackageAccess_name(), |
| vmSymbols::class_protectiondomain_signature(), |
| 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. |
| { |
| ClassLoaderData* loader_data = class_loader_data(class_loader); |
| Dictionary* dictionary = loader_data->dictionary(); |
| |
| Symbol* kn = klass->name(); |
| unsigned int d_hash = dictionary->compute_hash(kn); |
| int d_index = dictionary->hash_to_index(d_hash); |
| |
| MutexLocker mu(SystemDictionary_lock, THREAD); |
| dictionary->add_protection_domain(d_index, d_hash, klass, |
| 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 |
| InstanceKlass* SystemDictionary::handle_parallel_super_load( |
| Symbol* name, Symbol* superclassname, Handle class_loader, |
| Handle protection_domain, Handle lockObject, TRAPS) { |
| |
| ClassLoaderData* loader_data = class_loader_data(class_loader); |
| Dictionary* dictionary = loader_data->dictionary(); |
| unsigned int d_hash = dictionary->compute_hash(name); |
| int d_index = dictionary->hash_to_index(d_hash); |
| unsigned int p_hash = placeholders()->compute_hash(name); |
| 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_NULL); |
| |
| // 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 |
| return find_class(d_index, d_hash, name, dictionary); |
| } |
| |
| // 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 |
| InstanceKlass* check = find_class(d_index, d_hash, name, dictionary); |
| if (check != NULL) { |
| // Klass is already loaded, so just return it |
| return 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 NULL; |
| } |
| |
| static void post_class_load_event(EventClassLoad* event, |
| const InstanceKlass* k, |
| const ClassLoaderData* init_cld) { |
| #if INCLUDE_TRACE |
| assert(event != NULL, "invariant"); |
| assert(k != NULL, "invariant"); |
| if (event->should_commit()) { |
| event->set_loadedClass(k); |
| event->set_definingClassLoader(k->class_loader_data()); |
| event->set_initiatingClassLoader(init_cld); |
| event->commit(); |
| } |
| #endif // INCLUDE_TRACE |
| } |
| |
| static void class_define_event(InstanceKlass* k, |
| const ClassLoaderData* def_cld) { |
| #if INCLUDE_TRACE |
| EventClassDefine event; |
| if (event.should_commit()) { |
| event.set_definedClass(k); |
| event.set_definingClassLoader(def_cld); |
| event.commit(); |
| } |
| #endif // INCLUDE_TRACE |
| } |
| |
| // Be careful when modifying this code: once you have run |
| // placeholders()->find_and_add(PlaceholderTable::LOAD_INSTANCE), |
| // you need to find_and_remove it before returning. |
| // So be careful to not exit with a CHECK_ macro betweeen these calls. |
| 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"); |
| |
| EventClassLoad class_load_start_event; |
| |
| HandleMark hm(THREAD); |
| |
| // 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); |
| Dictionary* dictionary = loader_data->dictionary(); |
| |
| // 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); |
| int d_index = dictionary->hash_to_index(d_hash); |
| Klass* probe = dictionary->find(d_index, d_hash, name, protection_domain); |
| 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); |
| 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; |
| InstanceKlass* k = NULL; |
| PlaceholderEntry* placeholder; |
| Symbol* superclassname = NULL; |
| |
| { |
| MutexLocker mu(SystemDictionary_lock, THREAD); |
| InstanceKlass* check = find_class(d_index, d_hash, name, dictionary); |
| if (check != NULL) { |
| // Klass is already loaded, so just return it |
| class_has_been_loaded = true; |
| k = 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 = handle_parallel_super_load(name, |
| superclassname, |
| class_loader, |
| protection_domain, |
| lockObject, THREAD); |
| if (HAS_PENDING_EXCEPTION) { |
| return NULL; |
| } |
| if (k != 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 |
| InstanceKlass* check = find_class(d_index, d_hash, name, dictionary); |
| if (check != NULL) { |
| // Klass is already loaded, so just return it |
| k = 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 |
| InstanceKlass* check = find_class(d_index, d_hash, name, dictionary); |
| if (check != NULL) { |
| // Klass is already loaded, so return it after checking/adding protection domain |
| k = 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 == NULL && HAS_PENDING_EXCEPTION |
| && PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) { |
| MutexLocker mu(SystemDictionary_lock, THREAD); |
| InstanceKlass* check = find_class(d_index, d_hash, name, dictionary); |
| if (check != NULL) { |
| // Klass is already loaded, so just use it |
| k = 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 != 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 |
| |
| 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 == NULL) { |
| return NULL; |
| } |
| |
| post_class_load_event(&class_load_start_event, k, loader_data); |
| |
| #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 |
| if (dictionary->is_valid_protection_domain(d_index, d_hash, name, |
| 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; |
| } |
| |
| Dictionary* dictionary = loader_data->dictionary(); |
| unsigned int d_hash = dictionary->compute_hash(class_name); |
| int d_index = dictionary->hash_to_index(d_hash); |
| return dictionary->find(d_index, d_hash, class_name, |
| protection_domain); |
| } |
| |
| |
| // 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 |
| // does not publish the classes via the SystemDictionary. |
| // Handles unsafe_DefineAnonymousClass and redefineclasses |
| // RedefinedClasses do not add to the class hierarchy |
| InstanceKlass* SystemDictionary::parse_stream(Symbol* class_name, |
| Handle class_loader, |
| Handle protection_domain, |
| ClassFileStream* st, |
| const InstanceKlass* host_klass, |
| GrowableArray<Handle>* cp_patches, |
| TRAPS) { |
| |
| EventClassLoad class_load_start_event; |
| |
| 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"); |
| loader_data = ClassLoaderData::anonymous_class_loader_data(class_loader(), 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. |
| |
| InstanceKlass* k = KlassFactory::create_from_stream(st, |
| class_name, |
| loader_data, |
| protection_domain, |
| host_klass, |
| cp_patches, |
| CHECK_NULL); |
| |
| if (host_klass != NULL && k != 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 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_event, k, loader_data); |
| } |
| 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. |
| |
| InstanceKlass* SystemDictionary::resolve_from_stream(Symbol* class_name, |
| Handle class_loader, |
| Handle protection_domain, |
| ClassFileStream* st, |
| TRAPS) { |
| #if INCLUDE_CDS |
| ResourceMark rm(THREAD); |
| if (DumpSharedSpaces && !class_loader.is_null() && |
| !ArgumentsExt::using_AppCDS() && strcmp(class_name->as_C_string(), "Unnamed") != 0) { |
| // If AppCDS is not enabled, don't define the class at dump time (except for the "Unnamed" |
| // class, which is used by MethodHandles). |
| THROW_MSG_NULL(vmSymbols::java_lang_ClassNotFoundException(), class_name->as_C_string()); |
| } |
| #endif |
| |
| HandleMark hm(THREAD); |
| |
| // 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. |
| InstanceKlass* k = NULL; |
| |
| #if INCLUDE_CDS |
| if (!DumpSharedSpaces) { |
| k = SystemDictionaryShared::lookup_from_stream(class_name, |
| class_loader, |
| protection_domain, |
| st, |
| CHECK_NULL); |
| } |
| #endif |
| |
| if (k == NULL) { |
| if (st->buffer() == NULL) { |
| return NULL; |
| } |
| k = KlassFactory::create_from_stream(st, |
| class_name, |
| loader_data, |
| protection_domain, |
| NULL, // host_klass |
| NULL, // cp_patches |
| CHECK_NULL); |
| } |
| |
| assert(k != NULL, "no klass created"); |
| Symbol* h_name = k->name(); |
| assert(class_name == NULL || class_name == h_name, "name mismatch"); |
| |
| // 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)) { |
| InstanceKlass* defined_k = find_or_define_instance_class(h_name, class_loader, k, THREAD); |
| if (!HAS_PENDING_EXCEPTION && defined_k != k) { |
| // If a parallel capable class loader already defined this class, register 'k' for cleanup. |
| assert(defined_k != NULL, "Should have a klass if there's no exception"); |
| loader_data->add_to_deallocate_list(k); |
| k = defined_k; |
| } |
| } else { |
| define_instance_class(k, THREAD); |
| } |
| |
| // If defining the class throws an exception register 'k' for cleanup. |
| if (HAS_PENDING_EXCEPTION) { |
| assert(k != NULL, "Must have an instance klass here!"); |
| loader_data->add_to_deallocate_list(k); |
| return NULL; |
| } |
| |
| // Make sure we have an entry in the SystemDictionary on success |
| debug_only( { |
| MutexLocker mu(SystemDictionary_lock, THREAD); |
| |
| Klass* check = find_class(h_name, k->class_loader_data()); |
| assert(check == k, "should be present in the dictionary"); |
| } ); |
| |
| return k; |
| } |
| |
| #if INCLUDE_CDS |
| void SystemDictionary::set_shared_dictionary(HashtableBucket<mtClass>* t, int length, |
| int number_of_entries) { |
| assert(length == _shared_dictionary_size * sizeof(HashtableBucket<mtClass>), |
| "bad shared dictionary size."); |
| _shared_dictionary = new Dictionary(ClassLoaderData::the_null_class_loader_data(), |
| _shared_dictionary_size, t, number_of_entries); |
| } |
| |
| |
| // If there is a shared dictionary, then find the entry for the |
| // given shared system class, if any. |
| |
| InstanceKlass* SystemDictionary::find_shared_class(Symbol* class_name) { |
| if (shared_dictionary() != NULL) { |
| unsigned int d_hash = shared_dictionary()->compute_hash(class_name); |
| 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.] |
| |
| InstanceKlass* SystemDictionary::load_shared_class( |
| Symbol* class_name, Handle class_loader, TRAPS) { |
| InstanceKlass* ik = find_shared_class(class_name); |
| // Make sure we only return the boot class for the NULL classloader. |
| if (ik != NULL && |
| ik->is_shared_boot_class() && class_loader.is_null()) { |
| Handle protection_domain; |
| return load_shared_class(ik, class_loader, protection_domain, THREAD); |
| } |
| return NULL; |
| } |
| |
| // 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, |
| InstanceKlass* ik, |
| Handle class_loader, TRAPS) { |
| assert(!ModuleEntryTable::javabase_moduleEntry()->is_patched(), |
| "Cannot use sharing if java.base is patched"); |
| ResourceMark rm; |
| int path_index = ik->shared_classpath_index(); |
| ClassLoaderData* loader_data = class_loader_data(class_loader); |
| if (path_index < 0) { |
| // path_index < 0 indicates that the class is intended for a custom loader |
| // and should not be loaded by boot/platform/app loaders |
| if (loader_data->is_builtin_class_loader_data()) { |
| return false; |
| } else { |
| return true; |
| } |
| } |
| SharedClassPathEntry* ent = |
| (SharedClassPathEntry*)FileMapInfo::shared_classpath(path_index); |
| if (!Universe::is_module_initialized()) { |
| assert(ent != NULL && 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; |
| 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 the archived class is from a module that has been patched at runtime, |
| // the class cannot be loaded from the archive. |
| if (mod_entry != NULL && mod_entry->is_patched()) { |
| return false; |
| } |
| |
| if (class_loader.is_null()) { |
| assert(ent != NULL, "Shared class for NULL classloader must have valid SharedClassPathEntry"); |
| // 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->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; |
| } |
| } |
| |
| InstanceKlass* SystemDictionary::load_shared_class(InstanceKlass* ik, |
| Handle class_loader, |
| Handle protection_domain, TRAPS) { |
| |
| if (ik != NULL) { |
| Symbol* class_name = ik->name(); |
| |
| bool visible = is_shared_class_visible( |
| class_name, ik, class_loader, CHECK_NULL); |
| if (!visible) { |
| return NULL; |
| } |
| |
| // 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_NULL); |
| 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 NULL; |
| } 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); |
| Symbol* name = k->name(); |
| Klass* i = resolve_super_or_fail(class_name, name, class_loader, protection_domain, false, CHECK_NULL); |
| 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 NULL; |
| } else { |
| assert(i->is_shared(), "must be"); |
| } |
| } |
| |
| InstanceKlass* new_ik = KlassFactory::check_shared_class_file_load_hook( |
| ik, class_name, class_loader, protection_domain, CHECK_NULL); |
| if (new_ik != NULL) { |
| // The class is changed by CFLH. Return the new class. The shared class is |
| // not used. |
| return new_ik; |
| } |
| |
| // 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()); |
| { |
| HandleMark hm(THREAD); |
| Handle lockObject = compute_loader_lock_object(class_loader, THREAD); |
| check_loader_lock_contention(lockObject, THREAD); |
| ObjectLocker ol(lockObject, THREAD, true); |
| // prohibited package check assumes all classes loaded from archive call |
| // restore_unshareable_info which calls ik->set_package() |
| ik->restore_unshareable_info(loader_data, protection_domain, CHECK_NULL); |
| } |
| |
| ik->print_class_load_logging(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 */); |
| } |
| |
| ik->set_has_passed_fingerprint_check(false); |
| if (UseAOT && ik->supers_have_passed_fingerprint_checks()) { |
| uint64_t aot_fp = AOTLoader::get_saved_fingerprint(ik); |
| uint64_t cds_fp = ik->get_stored_fingerprint(); |
| if (aot_fp != 0 && aot_fp == cds_fp) { |
| // This class matches with a class saved in an AOT library |
| ik->set_has_passed_fingerprint_check(true); |
| } else { |
| ResourceMark rm; |
| log_info(class, fingerprint)("%s : expected = " PTR64_FORMAT " actual = " PTR64_FORMAT, ik->external_name(), aot_fp, cds_fp); |
| } |
| } |
| return ik; |
| } |
| |
| void SystemDictionary::clear_invoke_method_table() { |
| SymbolPropertyEntry* spe = NULL; |
| for (int index = 0; index < _invoke_method_table->table_size(); index++) { |
| SymbolPropertyEntry* p = _invoke_method_table->bucket(index); |
| while (p != NULL) { |
| spe = p; |
| p = p->next(); |
| _invoke_method_table->free_entry(spe); |
| } |
| } |
| } |
| #endif // INCLUDE_CDS |
| |
| InstanceKlass* SystemDictionary::load_instance_class(Symbol* class_name, Handle class_loader, TRAPS) { |
| |
| 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 NULL; |
| } |
| } 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 NULL; |
| } |
| } |
| } |
| } else { |
| // 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. |
| InstanceKlass* k = NULL; |
| { |
| #if INCLUDE_CDS |
| PerfTraceTime vmtimer(ClassLoader::perf_shared_classload_time()); |
| k = load_shared_class(class_name, class_loader, THREAD); |
| #endif |
| } |
| |
| if (k == NULL) { |
| // Use VM class loader |
| PerfTraceTime vmtimer(ClassLoader::perf_sys_classload_time()); |
| k = ClassLoader::load_class(class_name, search_only_bootloader_append, CHECK_NULL); |
| } |
| |
| // find_or_define_instance_class may return a different InstanceKlass |
| if (k != NULL) { |
| InstanceKlass* defined_k = |
| find_or_define_instance_class(class_name, class_loader, k, THREAD); |
| if (!HAS_PENDING_EXCEPTION && defined_k != k) { |
| // If a parallel capable class loader already defined this class, register 'k' for cleanup. |
| assert(defined_k != NULL, "Should have a klass if there's no exception"); |
| loader_data->add_to_deallocate_list(k); |
| k = defined_k; |
| } else if (HAS_PENDING_EXCEPTION) { |
| loader_data->add_to_deallocate_list(k); |
| return NULL; |
| } |
| } |
| 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_NULL); |
| // Translate to external class name format, i.e., convert '/' chars to '.' |
| Handle string = java_lang_String::externalize_classname(s, CHECK_NULL); |
| |
| JavaValue result(T_OBJECT); |
| |
| InstanceKlass* spec_klass = 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_NULL); |
| } else { |
| JavaCalls::call_virtual(&result, |
| class_loader, |
| spec_klass, |
| vmSymbols::loadClass_name(), |
| vmSymbols::string_class_signature(), |
| string, |
| CHECK_NULL); |
| } |
| |
| 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))) { |
| InstanceKlass* k = InstanceKlass::cast(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 NULL; |
| } |
| } |
| |
| void SystemDictionary::define_instance_class(InstanceKlass* k, TRAPS) { |
| |
| HandleMark hm(THREAD); |
| 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(); |
| Dictionary* dictionary = loader_data->dictionary(); |
| unsigned int d_hash = dictionary->compute_hash(name_h); |
| 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); |
| 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); |
| |
| } |
| class_define_event(k, loader_data); |
| } |
| |
| // 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 |
| // Be careful when modifying this code: once you have run |
| // placeholders()->find_and_add(PlaceholderTable::DEFINE_CLASS), |
| // you need to find_and_remove it before returning. |
| // So be careful to not exit with a CHECK_ macro betweeen these calls. |
| InstanceKlass* SystemDictionary::find_or_define_instance_class(Symbol* class_name, Handle class_loader, |
| InstanceKlass* k, TRAPS) { |
| |
| Symbol* name_h = k->name(); // passed in class_name may be null |
| ClassLoaderData* loader_data = class_loader_data(class_loader); |
| Dictionary* dictionary = loader_data->dictionary(); |
| |
| unsigned int d_hash = dictionary->compute_hash(name_h); |
| 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); |
| 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))) { |
| InstanceKlass* check = find_class(d_index, d_hash, name_h, dictionary); |
| if (check != NULL) { |
| return 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 |
| InstanceKlass* check = find_class(d_index, d_hash, name_h, dictionary); |
| assert(check != NULL, "definer missed recording success"); |
| #endif |
| return 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(), NULL); // 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 |
| |
| InstanceKlass* SystemDictionary::find_class(int index, unsigned int hash, |
| Symbol* class_name, |
| Dictionary* dictionary) { |
| assert_locked_or_safepoint(SystemDictionary_lock); |
| return dictionary->find_class(index, hash, class_name); |
| } |
| |
| |
| // 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); |
| 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 |
| // Precalculating the hash and index is an optimization because there are many lookups |
| // before adding the class. |
| InstanceKlass* SystemDictionary::find_class(Symbol* class_name, ClassLoaderData* loader_data) { |
| assert_locked_or_safepoint(SystemDictionary_lock); |
| #ifndef ASSERT |
| guarantee(VerifyBeforeGC || |
| VerifyDuringGC || |
| VerifyBeforeExit || |
| VerifyDuringStartup || |
| VerifyAfterGC, "too expensive"); |
| #endif |
| |
| Dictionary* dictionary = loader_data->dictionary(); |
| unsigned int d_hash = dictionary->compute_hash(class_name); |
| int d_index = dictionary->hash_to_index(d_hash); |
| return find_class(d_index, d_hash, class_name, dictionary); |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // 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(InstanceKlass* k, TRAPS) { |
| assert(k != 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 |
| |
| void SystemDictionary::always_strong_oops_do(OopClosure* blk) { |
| roots_oops_do(blk, NULL); |
| } |
| |
| |
| #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 protection domain cache table 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, |
| GCTimer* gc_timer, |
| bool do_cleaning) { |
| |
| |
| bool unloading_occurred; |
| { |
| GCTraceTime(Debug, gc, phases) t("ClassLoaderData", gc_timer); |
| |
| // First, mark for unload all ClassLoaderData referencing a dead class loader. |
| unloading_occurred = ClassLoaderDataGraph::do_unloading(is_alive, |
| do_cleaning); |
| } |
| |
| if (unloading_occurred) { |
| GCTraceTime(Debug, gc, phases) t("Dictionary", gc_timer); |
| constraints()->purge_loader_constraints(); |
| resolution_errors()->purge_resolution_errors(); |
| } |
| |
| { |
| GCTraceTime(Debug, gc, phases) t("ProtectionDomainCacheTable", gc_timer); |
| // Oops referenced by the protection domain cache table may get unreachable independently |
| // of the class loader (eg. cached protection domain oops). So we need to |
| // explicitly unlink them here. |
| _pd_cache_table->unlink(is_alive); |
| |
| #ifdef ASSERT |
| VerifySDReachableAndLiveClosure cl(is_alive); |
| _pd_cache_table->oops_do(&cl); |
| #endif |
| } |
| |
| if (do_cleaning) { |
| GCTraceTime(Debug, gc, phases) t("ResolvedMethodTable", gc_timer); |
| ResolvedMethodTable::unlink(is_alive); |
| } |
| |
| 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);) |
| |
| // Do strong roots marking if the closures are the same. |
| if (strong == weak || !ClassUnloading) { |
| // Only the protection domain oops contain references into the heap. Iterate |
| // over all of them. |
| _pd_cache_table->oops_do(strong); |
| } else { |
| if (weak != NULL) { |
| _pd_cache_table->oops_do(weak); |
| } |
| } |
| |
| // Visit extra methods |
| invoke_method_table()->oops_do(strong); |
| |
| if (weak != NULL) { |
| ResolvedMethodTable::oops_do(weak); |
| } |
| } |
| |
| 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);) |
| |
| // Only the protection domain oops contain references into the heap. Iterate |
| // over all of them. |
| _pd_cache_table->oops_do(f); |
| |
| // Visit extra methods |
| invoke_method_table()->oops_do(f); |
| |
| ResolvedMethodTable::oops_do(f); |
| } |
| |
| // CDS: scan and relocate all classes in the system dictionary. |
| void SystemDictionary::classes_do(MetaspaceClosure* it) { |
| ClassLoaderData::the_null_class_loader_data()->dictionary()->classes_do(it); |
| } |
| |
| // CDS: scan and relocate all classes referenced by _well_known_klasses[]. |
| void SystemDictionary::well_known_klasses_do(MetaspaceClosure* it) { |
| for (int id = FIRST_WKID; id < WKID_LIMIT; id++) { |
| it->push(well_known_klass_addr((WKID)id)); |
| } |
| } |
| |
| void SystemDictionary::methods_do(void f(Method*)) { |
| // Walk methods in loaded classes |
| ClassLoaderDataGraph::methods_do(f); |
| // Walk method handle intrinsics |
| invoke_method_table()->methods_do(f); |
| } |
| |
| class RemoveClassesClosure : public CLDClosure { |
| public: |
| void do_cld(ClassLoaderData* cld) { |
| if (cld->is_system_class_loader_data() || cld->is_platform_class_loader_data()) { |
| cld->dictionary()->remove_classes_in_error_state(); |
| } |
| } |
| }; |
| |
| void SystemDictionary::remove_classes_in_error_state() { |
| ClassLoaderData::the_null_class_loader_data()->dictionary()->remove_classes_in_error_state(); |
| RemoveClassesClosure rcc; |
| ClassLoaderDataGraph::cld_do(&rcc); |
| } |
| |
| // ---------------------------------------------------------------------------- |
| // 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 |
| _placeholders = new PlaceholderTable(_placeholder_table_size); |
| _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); |
| _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize); |
| |
| // 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::classLoader_init2(CHECK); |
| |
| // Preload commonly used klasses |
| WKID scan = FIRST_WKID; |
| // first do Object, then String, Class |
| #if INCLUDE_CDS |
| if (UseSharedSpaces) { |
| initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Object_klass), scan, CHECK); |
| // Initialize the constant pool for the Object_class |
| Object_klass()->constants()->restore_unshareable_info(CHECK); |
| initialize_wk_klasses_through(WK_KLASS_ENUM_NAME(Class_klass), scan, CHECK); |
| } else |
| #endif |
| { |
| 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 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 dictionary |
| // if initiating loader, then ok if InstanceKlass matches existing entry |
| |
| void SystemDictionary::check_constraints(int d_index, unsigned int d_hash, |
| InstanceKlass* 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); |
| |
| InstanceKlass* check = find_class(d_index, d_hash, name, loader_data->dictionary()); |
| if (check != 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 |
| // 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 class loader data 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, |
| InstanceKlass* 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 dictionary entry. |
| Dictionary* dictionary = loader_data->dictionary(); |
| InstanceKlass* sd_check = find_class(d_index, d_hash, name, dictionary); |
| if (sd_check == NULL) { |
| dictionary->add_klass(d_index, d_hash, name, k); |
| notice_modification(); |
| } |
| #ifdef ASSERT |
| sd_check = find_class(d_index, d_hash, name, dictionary); |
| assert (sd_check != NULL, "should have entry in 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(); |
| } |
| } |
| |
| Dictionary* dictionary1 = loader_data1->dictionary(); |
| unsigned int d_hash1 = dictionary1->compute_hash(constraint_name); |
| int d_index1 = dictionary1->hash_to_index(d_hash1); |
| |
| Dictionary* dictionary2 = loader_data2->dictionary(); |
| unsigned int d_hash2 = dictionary2->compute_hash(constraint_name); |
| int d_index2 = dictionary2->hash_to_index(d_hash2); |
| |
| { |
| MutexLocker mu_s(SystemDictionary_lock, THREAD); |
| InstanceKlass* klass1 = find_class(d_index1, d_hash1, constraint_name, dictionary1); |
| InstanceKlass* klass2 = find_class(d_index2, d_hash2, constraint_name, dictionary2); |
| 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, |
| Klass* accessing_klass, |
| objArrayHandle appendix_box, |
| Handle* appendix_result, |
| TRAPS) { |
| methodHandle empty; |
| if (mname.not_null()) { |
| Method* m = java_lang_invoke_MemberName::vmtarget(mname()); |
| if (m != NULL) { |
| 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 = 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(Klass* klass, |
| Symbol* name, |
| Symbol* signature, |
| Klass* 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; |
| oop name_oop = StringTable::intern(name, CHECK_(empty)); |
| Handle name_str (THREAD, name_oop); |
| objArrayHandle appendix_box = oopFactory::new_objArray_handle(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 == 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(Handle(THREAD, accessing_klass->java_mirror())); |
| args.push_int(ref_kind); |
| args.push_oop(Handle(THREAD, 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, |
| Klass* 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 != NULL) { |
| class_loader = Handle(THREAD, accessing_klass->class_loader()); |
| protection_domain = Handle(THREAD, accessing_klass->protection_domain()); |
| } |
| bool can_be_cached = true; |
| int npts = ArgumentCount(signature).size(); |
| objArrayHandle pts = oopFactory::new_objArray_handle(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 != 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()) { |
| LinkResolver::check_klass_accessability(accessing_klass, sel_klass, CHECK_(empty)); |
| } |
| } |
| } |
| assert(arg == npts, ""); |
| |
| // call java.lang.invoke.MethodHandleNatives::findMethodHandleType(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(Klass* caller, |
| int ref_kind, //e.g., JVM_REF_invokeVirtual |
| Klass* 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 == 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(Handle(THREAD, caller->class_loader()), |
| Handle(THREAD, 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(Handle(THREAD, caller->java_mirror())); // the referring class |
| args.push_int(ref_kind); |
| args.push_oop(Handle(THREAD, 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(Klass* 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 == NULL || method_type.is_null()) { |
| THROW_MSG_(vmSymbols::java_lang_InternalError(), "bad invokedynamic", empty); |
| } |
| |
| objArrayHandle appendix_box = oopFactory::new_objArray_handle(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(Handle(THREAD, 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); |
| } |
| |
| // Protection domain cache table handling |
| |
| ProtectionDomainCacheEntry* SystemDictionary::cache_get(Handle protection_domain) { |
| return _pd_cache_table->get(protection_domain); |
| } |
| |
| void SystemDictionary::reorder_dictionary_for_sharing() { |
| ClassLoaderData::the_null_class_loader_data()->dictionary()->reorder_dictionary_for_sharing(); |
| } |
| |
| size_t SystemDictionary::count_bytes_for_buckets() { |
| return ClassLoaderData::the_null_class_loader_data()->dictionary()->count_bytes_for_buckets(); |
| } |
| |
| size_t SystemDictionary::count_bytes_for_table() { |
| return ClassLoaderData::the_null_class_loader_data()->dictionary()->count_bytes_for_table(); |
| } |
| |
| void SystemDictionary::copy_buckets(char* top, char* end) { |
| ClassLoaderData::the_null_class_loader_data()->dictionary()->copy_buckets(top, end); |
| } |
| |
| void SystemDictionary::copy_table(char* top, char* end) { |
| ClassLoaderData::the_null_class_loader_data()->dictionary()->copy_table(top, end); |
| } |
| |
| // ---------------------------------------------------------------------------- |
| void SystemDictionary::print_shared(outputStream *st) { |
| shared_dictionary()->print_on(st); |
| } |
| |
| void SystemDictionary::print_on(outputStream *st) { |
| if (shared_dictionary() != NULL) { |
| st->print_cr("Shared Dictionary"); |
| shared_dictionary()->print_on(st); |
| st->cr(); |
| } |
| |
| GCMutexLocker mu(SystemDictionary_lock); |
| |
| ClassLoaderDataGraph::print_dictionary(st); |
| |
| // Placeholders |
| placeholders()->print_on(st); |
| st->cr(); |
| |
| // loader constraints - print under SD_lock |
| constraints()->print_on(st); |
| st->cr(); |
| |
| _pd_cache_table->print_on(st); |
| st->cr(); |
| } |
| |
| void SystemDictionary::verify() { |
| guarantee(constraints() != NULL, |
| "Verify of loader constraints failed"); |
| guarantee(placeholders()->number_of_entries() >= 0, |
| "Verify of placeholders failed"); |
| |
| GCMutexLocker mu(SystemDictionary_lock); |
| |
| // Verify dictionary |
| ClassLoaderDataGraph::verify_dictionary(); |
| |
| placeholders()->verify(); |
| |
| // Verify constraint table |
| guarantee(constraints() != NULL, "Verify of loader constraints failed"); |
| constraints()->verify(placeholders()); |
| |
| _pd_cache_table->verify(); |
| } |
| |
| void SystemDictionary::dump(outputStream *st, bool verbose) { |
| assert_locked_or_safepoint(SystemDictionary_lock); |
| if (verbose) { |
| print_on(st); |
| } else { |
| if (shared_dictionary() != NULL) { |
| shared_dictionary()->print_table_statistics(st, "Shared Dictionary"); |
| } |
| ClassLoaderDataGraph::print_dictionary_statistics(st); |
| placeholders()->print_table_statistics(st, "Placeholder Table"); |
| constraints()->print_table_statistics(st, "LoaderConstraints Table"); |
| _pd_cache_table->print_table_statistics(st, "ProtectionDomainCache Table"); |
| } |
| } |
| |
| // Utility for dumping dictionaries. |
| SystemDictionaryDCmd::SystemDictionaryDCmd(outputStream* output, bool heap) : |
| DCmdWithParser(output, heap), |
| _verbose("-verbose", "Dump the content of each dictionary entry for all class loaders", |
| "BOOLEAN", false, "false") { |
| _dcmdparser.add_dcmd_option(&_verbose); |
| } |
| |
| void SystemDictionaryDCmd::execute(DCmdSource source, TRAPS) { |
| VM_DumpHashtable dumper(output(), VM_DumpHashtable::DumpSysDict, |
| _verbose.value()); |
| VMThread::execute(&dumper); |
| } |
| |
| int SystemDictionaryDCmd::num_arguments() { |
| ResourceMark rm; |
| SystemDictionaryDCmd* dcmd = new SystemDictionaryDCmd(NULL, false); |
| if (dcmd != NULL) { |
| DCmdMark mark(dcmd); |
| return dcmd->_dcmdparser.num_arguments(); |
| } else { |
| return 0; |
| } |
| } |
| |
| class CombineDictionariesClosure : public CLDClosure { |
| private: |
| Dictionary* _master_dictionary; |
| public: |
| CombineDictionariesClosure(Dictionary* master_dictionary) : |
| _master_dictionary(master_dictionary) {} |
| void do_cld(ClassLoaderData* cld) { |
| ResourceMark rm; |
| if (cld->is_system_class_loader_data() || cld->is_platform_class_loader_data()) { |
| for (int i = 0; i < cld->dictionary()->table_size(); ++i) { |
| Dictionary* curr_dictionary = cld->dictionary(); |
| DictionaryEntry* p = curr_dictionary->bucket(i); |
| while (p != NULL) { |
| Symbol* name = p->instance_klass()->name(); |
| unsigned int d_hash = _master_dictionary->compute_hash(name); |
| int d_index = _master_dictionary->hash_to_index(d_hash); |
| DictionaryEntry* next = p->next(); |
| if (p->literal()->class_loader_data() != cld) { |
| // This is an initiating class loader entry; don't use it |
| log_trace(cds)("Skipping initiating cl entry: %s", name->as_C_string()); |
| curr_dictionary->free_entry(p); |
| } else { |
| log_trace(cds)("Moved to boot dictionary: %s", name->as_C_string()); |
| curr_dictionary->unlink_entry(p); |
| p->set_pd_set(NULL); // pd_set is runtime only information and will be reconstructed. |
| _master_dictionary->add_entry(d_index, p); |
| } |
| p = next; |
| } |
| *curr_dictionary->bucket_addr(i) = NULL; |
| } |
| } |
| } |
| }; |
| |
| // Combining platform and system loader dictionaries into boot loader dictionaries. |
| // During run time, we only have one shared dictionary. |
| void SystemDictionary::combine_shared_dictionaries() { |
| assert(DumpSharedSpaces, "dump time only"); |
| Dictionary* master_dictionary = ClassLoaderData::the_null_class_loader_data()->dictionary(); |
| CombineDictionariesClosure cdc(master_dictionary); |
| ClassLoaderDataGraph::cld_do(&cdc); |
| |
| // These tables are no longer valid or necessary. Keeping them around will |
| // cause SystemDictionary::verify() to fail. Let's empty them. |
| _placeholders = new PlaceholderTable(_placeholder_table_size); |
| _loader_constraints = new LoaderConstraintTable(_loader_constraint_size); |
| |
| NOT_PRODUCT(SystemDictionary::verify()); |
| } |
| |
| // 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>" : |
| SystemDictionary::loader_name(loader_data->class_loader())); |
| } |