--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/classfile/systemDictionary.cpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,3013 @@
+/*
+ * 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()));
+}