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third-party-mirror/openjdk/jdk25u/refs/heads/master/./src/hotspot/share/classfile/systemDictionaryShared.cpp
blob: bdf558b4a48f729bd89a31e40ab52bc58648e9d3 [file] [edit]
/*
* Copyright (c) 2014, 2025, 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 "cds/aotClassFilter.hpp"
#include "cds/aotClassLocation.hpp"
#include "cds/aotLogging.hpp"
#include "cds/archiveBuilder.hpp"
#include "cds/archiveUtils.hpp"
#include "cds/cdsConfig.hpp"
#include "cds/cdsProtectionDomain.hpp"
#include "cds/classListParser.hpp"
#include "cds/classListWriter.hpp"
#include "cds/dumpTimeClassInfo.inline.hpp"
#include "cds/dynamicArchive.hpp"
#include "cds/filemap.hpp"
#include "cds/heapShared.hpp"
#include "cds/lambdaProxyClassDictionary.hpp"
#include "cds/lambdaFormInvokers.inline.hpp"
#include "cds/metaspaceShared.hpp"
#include "cds/runTimeClassInfo.hpp"
#include "cds/unregisteredClasses.hpp"
#include "classfile/classFileStream.hpp"
#include "classfile/classLoader.hpp"
#include "classfile/classLoaderData.inline.hpp"
#include "classfile/classLoaderDataGraph.hpp"
#include "classfile/classLoaderExt.hpp"
#include "classfile/dictionary.hpp"
#include "classfile/javaClasses.hpp"
#include "classfile/javaClasses.inline.hpp"
#include "classfile/symbolTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/systemDictionaryShared.hpp"
#include "classfile/verificationType.hpp"
#include "classfile/vmClasses.hpp"
#include "classfile/vmSymbols.hpp"
#include "jfr/jfrEvents.hpp"
#include "logging/log.hpp"
#include "logging/logStream.hpp"
#include "memory/allocation.hpp"
#include "memory/metadataFactory.hpp"
#include "memory/metaspaceClosure.hpp"
#include "memory/oopFactory.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.hpp"
#include "oops/compressedKlass.inline.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/klass.inline.hpp"
#include "oops/objArrayKlass.hpp"
#include "oops/objArrayOop.inline.hpp"
#include "oops/oop.inline.hpp"
#include "oops/oopHandle.inline.hpp"
#include "oops/typeArrayOop.inline.hpp"
#include "runtime/arguments.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/java.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/mutexLocker.hpp"
#include "utilities/resourceHash.hpp"
#include "utilities/stringUtils.hpp"
SystemDictionaryShared::ArchiveInfo SystemDictionaryShared::_static_archive;
SystemDictionaryShared::ArchiveInfo SystemDictionaryShared::_dynamic_archive;
DumpTimeSharedClassTable* SystemDictionaryShared::_dumptime_table = nullptr;
// Used by NoClassLoadingMark
DEBUG_ONLY(bool SystemDictionaryShared::_class_loading_may_happen = true;)
#ifdef ASSERT
static void check_klass_after_loading(const Klass* k) {
#ifdef _LP64
if (k != nullptr && UseCompressedClassPointers) {
CompressedKlassPointers::check_encodable(k);
}
#endif
}
#endif
InstanceKlass* SystemDictionaryShared::load_shared_class_for_builtin_loader(
Symbol* class_name, Handle class_loader, TRAPS) {
assert(CDSConfig::is_using_archive(), "must be");
InstanceKlass* ik = find_builtin_class(class_name);
if (ik != nullptr && !ik->shared_loading_failed()) {
if ((SystemDictionary::is_system_class_loader(class_loader()) && ik->defined_by_app_loader()) ||
(SystemDictionary::is_platform_class_loader(class_loader()) && ik->defined_by_platform_loader())) {
SharedClassLoadingMark slm(THREAD, ik);
PackageEntry* pkg_entry = CDSProtectionDomain::get_package_entry_from_class(ik, class_loader);
Handle protection_domain =
CDSProtectionDomain::init_security_info(class_loader, ik, pkg_entry, CHECK_NULL);
return load_shared_class(ik, class_loader, protection_domain, nullptr, pkg_entry, THREAD);
}
}
return nullptr;
}
// This function is called for loading only UNREGISTERED classes
InstanceKlass* SystemDictionaryShared::lookup_from_stream(Symbol* class_name,
Handle class_loader,
Handle protection_domain,
const ClassFileStream* cfs,
TRAPS) {
if (!CDSConfig::is_using_archive()) {
return nullptr;
}
if (class_name == nullptr) { // don't do this for hidden classes
return nullptr;
}
if (class_loader.is_null() ||
SystemDictionary::is_system_class_loader(class_loader()) ||
SystemDictionary::is_platform_class_loader(class_loader())) {
// Do nothing for the BUILTIN loaders.
return nullptr;
}
const RunTimeClassInfo* record = find_record(&_static_archive._unregistered_dictionary,
&_dynamic_archive._unregistered_dictionary,
class_name);
if (record == nullptr) {
return nullptr;
}
int clsfile_size = cfs->length();
int clsfile_crc32 = ClassLoader::crc32(0, (const char*)cfs->buffer(), cfs->length());
if (!record->matches(clsfile_size, clsfile_crc32)) {
return nullptr;
}
return acquire_class_for_current_thread(record->klass(), class_loader,
protection_domain, cfs,
THREAD);
}
InstanceKlass* SystemDictionaryShared::acquire_class_for_current_thread(
InstanceKlass *ik,
Handle class_loader,
Handle protection_domain,
const ClassFileStream *cfs,
TRAPS) {
ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
{
MutexLocker mu(THREAD, SharedDictionary_lock);
if (ik->class_loader_data() != nullptr) {
// ik is already loaded (by this loader or by a different loader)
// or ik is being loaded by a different thread (by this loader or by a different loader)
return nullptr;
}
// No other thread has acquired this yet, so give it to *this thread*
ik->set_class_loader_data(loader_data);
}
// No longer holding SharedDictionary_lock
// No need to lock, as <ik> can be held only by a single thread.
loader_data->add_class(ik);
// Get the package entry.
PackageEntry* pkg_entry = CDSProtectionDomain::get_package_entry_from_class(ik, class_loader);
// Load and check super/interfaces, restore unshareable info
InstanceKlass* shared_klass = load_shared_class(ik, class_loader, protection_domain,
cfs, pkg_entry, THREAD);
if (shared_klass == nullptr || HAS_PENDING_EXCEPTION) {
// TODO: clean up <ik> so it can be used again
return nullptr;
}
return shared_klass;
}
// Guaranteed to return non-null value for non-shared classes.
// k must not be a shared class.
DumpTimeClassInfo* SystemDictionaryShared::get_info(InstanceKlass* k) {
MutexLocker ml(DumpTimeTable_lock, Mutex::_no_safepoint_check_flag);
return get_info_locked(k);
}
DumpTimeClassInfo* SystemDictionaryShared::get_info_locked(InstanceKlass* k) {
assert_lock_strong(DumpTimeTable_lock);
DumpTimeClassInfo* info = _dumptime_table->get_info(k);
assert(info != nullptr, "must be");
return info;
}
bool SystemDictionaryShared::check_for_exclusion(InstanceKlass* k, DumpTimeClassInfo* info) {
if (CDSConfig::is_dumping_dynamic_archive() && MetaspaceShared::is_in_shared_metaspace(k)) {
// We have reached a super type that's already in the base archive. Treat it
// as "not excluded".
return false;
}
if (info == nullptr) {
info = _dumptime_table->get(k);
assert(info != nullptr, "supertypes of any classes in _dumptime_table must either be shared, or must also be in _dumptime_table");
}
if (!info->has_checked_exclusion()) {
if (check_for_exclusion_impl(k)) {
info->set_excluded();
}
info->set_has_checked_exclusion();
}
return info->is_excluded();
}
// Returns true so the caller can do: return warn_excluded(".....");
bool SystemDictionaryShared::warn_excluded(InstanceKlass* k, const char* reason) {
ResourceMark rm;
aot_log_warning(aot)("Skipping %s: %s", k->name()->as_C_string(), reason);
return true;
}
bool SystemDictionaryShared::is_jfr_event_class(InstanceKlass *k) {
while (k) {
if (k->name()->equals("jdk/internal/event/Event")) {
return true;
}
k = k->java_super();
}
return false;
}
bool SystemDictionaryShared::is_early_klass(InstanceKlass* ik) {
DumpTimeClassInfo* info = _dumptime_table->get(ik);
return (info != nullptr) ? info->is_early_klass() : false;
}
bool SystemDictionaryShared::check_for_exclusion_impl(InstanceKlass* k) {
if (CDSConfig::is_dumping_final_static_archive() && k->defined_by_other_loaders()
&& k->is_shared()) {
return false; // Do not exclude: unregistered classes are passed from preimage to final image.
}
if (k->is_in_error_state()) {
return warn_excluded(k, "In error state");
}
if (k->is_scratch_class()) {
return warn_excluded(k, "A scratch class");
}
if (!k->is_loaded()) {
return warn_excluded(k, "Not in loaded state");
}
if (has_been_redefined(k)) {
return warn_excluded(k, "Has been redefined");
}
if (!k->is_hidden() && k->shared_classpath_index() < 0 && is_builtin(k)) {
if (k->name()->starts_with("java/lang/invoke/BoundMethodHandle$Species_")) {
// This class is dynamically generated by the JDK
if (CDSConfig::is_dumping_method_handles()) {
k->set_shared_classpath_index(0);
} else {
ResourceMark rm;
aot_log_info(aot)("Skipping %s because it is dynamically generated", k->name()->as_C_string());
return true; // exclude without warning
}
} else {
// These are classes loaded from unsupported locations (such as those loaded by JVMTI native
// agent during dump time).
return warn_excluded(k, "Unsupported location");
}
}
if (k->signers() != nullptr) {
// We cannot include signed classes in the archive because the certificates
// used during dump time may be different than those used during
// runtime (due to expiration, etc).
return warn_excluded(k, "Signed JAR");
}
if (is_jfr_event_class(k)) {
// We cannot include JFR event classes because they need runtime-specific
// instrumentation in order to work with -XX:FlightRecorderOptions:retransform=false.
// There are only a small number of these classes, so it's not worthwhile to
// support them and make CDS more complicated.
return warn_excluded(k, "JFR event class");
}
if (!k->is_linked()) {
if (has_class_failed_verification(k)) {
return warn_excluded(k, "Failed verification");
} else if (CDSConfig::is_dumping_aot_linked_classes()) {
// Most loaded classes should have been speculatively linked by MetaspaceShared::link_class_for_cds().
// However, we do not speculatively link old classes, as they are not recorded by
// SystemDictionaryShared::record_linking_constraint(). As a result, such an unlinked
// class may fail to verify in AOTLinkedClassBulkLoader::init_required_classes_for_loader(),
// causing the JVM to fail at bootstrap.
return warn_excluded(k, "Unlinked class not supported by AOTClassLinking");
} else if (CDSConfig::is_dumping_preimage_static_archive()) {
// When dumping the final static archive, we will unconditionally load and link all
// classes from the preimage. We don't want to get a VerifyError when linking this class.
return warn_excluded(k, "Unlinked class not supported by AOTConfiguration");
}
} else {
if (!k->can_be_verified_at_dumptime()) {
// We have an old class that has been linked (e.g., it's been executed during
// dump time). This class has been verified using the old verifier, which
// doesn't save the verification constraints, so check_verification_constraints()
// won't work at runtime.
// As a result, we cannot store this class. It must be loaded and fully verified
// at runtime.
return warn_excluded(k, "Old class has been linked");
}
}
if (UnregisteredClasses::check_for_exclusion(k)) {
ResourceMark rm;
aot_log_info(aot)("Skipping %s: used only when dumping CDS archive", k->name()->as_C_string());
return true;
}
InstanceKlass* super = k->java_super();
if (super != nullptr && check_for_exclusion(super, nullptr)) {
ResourceMark rm;
aot_log_warning(aot)("Skipping %s: super class %s is excluded", k->name()->as_C_string(), super->name()->as_C_string());
return true;
}
Array<InstanceKlass*>* interfaces = k->local_interfaces();
int len = interfaces->length();
for (int i = 0; i < len; i++) {
InstanceKlass* intf = interfaces->at(i);
if (check_for_exclusion(intf, nullptr)) {
ResourceMark rm;
aot_log_warning(aot)("Skipping %s: interface %s is excluded", k->name()->as_C_string(), intf->name()->as_C_string());
return true;
}
}
return false; // false == k should NOT be excluded
}
bool SystemDictionaryShared::is_builtin_loader(ClassLoaderData* loader_data) {
oop class_loader = loader_data->class_loader();
return (class_loader == nullptr ||
SystemDictionary::is_system_class_loader(class_loader) ||
SystemDictionary::is_platform_class_loader(class_loader));
}
bool SystemDictionaryShared::has_platform_or_app_classes() {
if (FileMapInfo::current_info()->has_platform_or_app_classes()) {
return true;
}
if (DynamicArchive::is_mapped() &&
FileMapInfo::dynamic_info()->has_platform_or_app_classes()) {
return true;
}
return false;
}
// The following stack shows how this code is reached:
//
// [0] SystemDictionaryShared::find_or_load_shared_class()
// [1] JVM_FindLoadedClass
// [2] java.lang.ClassLoader.findLoadedClass0()
// [3] java.lang.ClassLoader.findLoadedClass()
// [4] jdk.internal.loader.BuiltinClassLoader.loadClassOrNull()
// [5] jdk.internal.loader.BuiltinClassLoader.loadClass()
// [6] jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(), or
// jdk.internal.loader.ClassLoaders$PlatformClassLoader.loadClass()
//
// AppCDS supports fast class loading for these 2 built-in class loaders:
// jdk.internal.loader.ClassLoaders$PlatformClassLoader
// jdk.internal.loader.ClassLoaders$AppClassLoader
// with the following assumptions (based on the JDK core library source code):
//
// [a] these two loaders use the BuiltinClassLoader.loadClassOrNull() to
// load the named class.
// [b] BuiltinClassLoader.loadClassOrNull() first calls findLoadedClass(name).
// [c] At this point, if we can find the named class inside the
// shared_dictionary, we can perform further checks (see
// SystemDictionary::is_shared_class_visible) to ensure that this class
// was loaded by the same class loader during dump time.
//
// Given these assumptions, we intercept the findLoadedClass() call to invoke
// SystemDictionaryShared::find_or_load_shared_class() to load the shared class from
// the archive for the 2 built-in class loaders. This way,
// we can improve start-up because we avoid decoding the classfile,
// and avoid delegating to the parent loader.
//
// NOTE: there's a lot of assumption about the Java code. If any of that change, this
// needs to be redesigned.
InstanceKlass* SystemDictionaryShared::find_or_load_shared_class(
Symbol* name, Handle class_loader, TRAPS) {
InstanceKlass* k = nullptr;
if (CDSConfig::is_using_archive()) {
if (!has_platform_or_app_classes()) {
return nullptr;
}
if (SystemDictionary::is_system_class_loader(class_loader()) ||
SystemDictionary::is_platform_class_loader(class_loader())) {
ClassLoaderData *loader_data = register_loader(class_loader);
Dictionary* dictionary = loader_data->dictionary();
// Note: currently, find_or_load_shared_class is called only from
// JVM_FindLoadedClass and used for PlatformClassLoader and AppClassLoader,
// which are parallel-capable loaders, so a lock here is NOT taken.
assert(get_loader_lock_or_null(class_loader) == nullptr, "ObjectLocker not required");
{
MutexLocker mu(THREAD, SystemDictionary_lock);
InstanceKlass* check = dictionary->find_class(THREAD, name);
if (check != nullptr) {
return check;
}
}
k = load_shared_class_for_builtin_loader(name, class_loader, THREAD);
if (k != nullptr) {
SharedClassLoadingMark slm(THREAD, k);
k = find_or_define_instance_class(name, class_loader, k, CHECK_NULL);
}
}
}
DEBUG_ONLY(check_klass_after_loading(k);)
return k;
}
class UnregisteredClassesTable : public ResourceHashtable<
Symbol*, InstanceKlass*,
15889, // prime number
AnyObj::C_HEAP> {};
static UnregisteredClassesTable* _unregistered_classes_table = nullptr;
// true == class was successfully added; false == a duplicated class (with the same name) already exists.
bool SystemDictionaryShared::add_unregistered_class(Thread* current, InstanceKlass* klass) {
// We don't allow duplicated unregistered classes with the same name.
// We only archive the first class with that name that succeeds putting
// itself into the table.
assert(CDSConfig::is_dumping_archive() || ClassListWriter::is_enabled(), "sanity");
MutexLocker ml(current, UnregisteredClassesTable_lock, Mutex::_no_safepoint_check_flag);
Symbol* name = klass->name();
if (_unregistered_classes_table == nullptr) {
_unregistered_classes_table = new (mtClass)UnregisteredClassesTable();
}
bool created;
InstanceKlass** v = _unregistered_classes_table->put_if_absent(name, klass, &created);
if (created) {
name->increment_refcount();
}
return (klass == *v);
}
InstanceKlass* SystemDictionaryShared::get_unregistered_class(Symbol* name) {
assert(CDSConfig::is_dumping_archive() || ClassListWriter::is_enabled(), "sanity");
if (_unregistered_classes_table == nullptr) {
return nullptr;
}
InstanceKlass** k = _unregistered_classes_table->get(name);
return k != nullptr ? *k : nullptr;
}
void SystemDictionaryShared::copy_unregistered_class_size_and_crc32(InstanceKlass* klass) {
precond(CDSConfig::is_dumping_final_static_archive());
precond(klass->is_shared());
// A shared class must have a RunTimeClassInfo record
const RunTimeClassInfo* record = find_record(&_static_archive._unregistered_dictionary,
nullptr, klass->name());
precond(record != nullptr);
precond(record->klass() == klass);
DumpTimeClassInfo* info = get_info(klass);
info->_clsfile_size = record->crc()->_clsfile_size;
info->_clsfile_crc32 = record->crc()->_clsfile_crc32;
}
void SystemDictionaryShared::set_shared_class_misc_info(InstanceKlass* k, ClassFileStream* cfs) {
assert(CDSConfig::is_dumping_archive(), "sanity");
assert(!is_builtin(k), "must be unregistered class");
DumpTimeClassInfo* info = get_info(k);
info->_clsfile_size = cfs->length();
info->_clsfile_crc32 = ClassLoader::crc32(0, (const char*)cfs->buffer(), cfs->length());
}
void SystemDictionaryShared::initialize() {
if (CDSConfig::is_dumping_archive()) {
_dumptime_table = new (mtClass) DumpTimeSharedClassTable;
LambdaProxyClassDictionary::dumptime_init();
if (CDSConfig::is_dumping_heap()) {
HeapShared::init_dumping();
}
}
}
void SystemDictionaryShared::init_dumptime_info(InstanceKlass* k) {
MutexLocker ml(DumpTimeTable_lock, Mutex::_no_safepoint_check_flag);
assert(SystemDictionaryShared::class_loading_may_happen(), "sanity");
DumpTimeClassInfo* info = _dumptime_table->allocate_info(k);
if (AOTClassFilter::is_aot_tooling_class(k)) {
info->set_is_aot_tooling_class();
}
}
void SystemDictionaryShared::remove_dumptime_info(InstanceKlass* k) {
MutexLocker ml(DumpTimeTable_lock, Mutex::_no_safepoint_check_flag);
_dumptime_table->remove(k);
}
void SystemDictionaryShared::handle_class_unloading(InstanceKlass* klass) {
if (CDSConfig::is_dumping_archive()) {
remove_dumptime_info(klass);
}
if (CDSConfig::is_dumping_archive() || ClassListWriter::is_enabled()) {
MutexLocker ml(Thread::current(), UnregisteredClassesTable_lock, Mutex::_no_safepoint_check_flag);
if (_unregistered_classes_table != nullptr) {
// Remove the class from _unregistered_classes_table: keep the entry but
// set it to null. This ensure no classes with the same name can be
// added again.
InstanceKlass** v = _unregistered_classes_table->get(klass->name());
if (v != nullptr) {
*v = nullptr;
}
}
} else {
assert(_unregistered_classes_table == nullptr, "must not be used");
}
if (ClassListWriter::is_enabled()) {
ClassListWriter cw;
cw.handle_class_unloading((const InstanceKlass*)klass);
}
}
void SystemDictionaryShared::init_dumptime_info_from_preimage(InstanceKlass* k) {
init_dumptime_info(k);
copy_verification_constraints_from_preimage(k);
copy_linking_constraints_from_preimage(k);
if (SystemDictionary::is_platform_class_loader(k->class_loader())) {
AOTClassLocationConfig::dumptime_set_has_platform_classes();
} else if (SystemDictionary::is_system_class_loader(k->class_loader())) {
AOTClassLocationConfig::dumptime_set_has_app_classes();
}
}
// Check if a class or any of its supertypes has been redefined.
bool SystemDictionaryShared::has_been_redefined(InstanceKlass* k) {
if (k->has_been_redefined()) {
return true;
}
if (k->java_super() != nullptr && has_been_redefined(k->java_super())) {
return true;
}
Array<InstanceKlass*>* interfaces = k->local_interfaces();
int len = interfaces->length();
for (int i = 0; i < len; i++) {
if (has_been_redefined(interfaces->at(i))) {
return true;
}
}
return false;
}
// k is a class before relocating by ArchiveBuilder
void SystemDictionaryShared::validate_before_archiving(InstanceKlass* k) {
ResourceMark rm;
const char* name = k->name()->as_C_string();
DumpTimeClassInfo* info = _dumptime_table->get(k);
assert(!class_loading_may_happen(), "class loading must be disabled");
guarantee(info != nullptr, "Class %s must be entered into _dumptime_table", name);
guarantee(!info->is_excluded(), "Should not attempt to archive excluded class %s", name);
if (is_builtin(k)) {
if (k->is_hidden()) {
if (CDSConfig::is_dumping_lambdas_in_legacy_mode()) {
assert(LambdaProxyClassDictionary::is_registered_lambda_proxy_class(k), "unexpected hidden class %s", name);
}
}
guarantee(!k->defined_by_other_loaders(),
"Class loader type must be set for BUILTIN class %s", name);
} else {
guarantee(k->defined_by_other_loaders(),
"Class loader type must not be set for UNREGISTERED class %s", name);
}
}
class UnregisteredClassesDuplicationChecker : StackObj {
GrowableArray<InstanceKlass*> _list;
Thread* _thread;
public:
UnregisteredClassesDuplicationChecker() : _thread(Thread::current()) {}
void do_entry(InstanceKlass* k, DumpTimeClassInfo& info) {
if (!SystemDictionaryShared::is_builtin(k)) {
_list.append(k);
}
}
static int compare_by_loader(InstanceKlass** a, InstanceKlass** b) {
ClassLoaderData* loader_a = a[0]->class_loader_data();
ClassLoaderData* loader_b = b[0]->class_loader_data();
if (loader_a != loader_b) {
return primitive_compare(loader_a, loader_b);
} else {
return primitive_compare(a[0], b[0]);
}
}
void mark_duplicated_classes() {
// Two loaders may load two identical or similar hierarchies of classes. If we
// check for duplication in random order, we may end up excluding important base classes
// in both hierarchies, causing most of the classes to be excluded.
// We sort the classes by their loaders. This way we're likely to archive
// all classes in the one of the two hierarchies.
_list.sort(compare_by_loader);
for (int i = 0; i < _list.length(); i++) {
InstanceKlass* k = _list.at(i);
bool i_am_first = SystemDictionaryShared::add_unregistered_class(_thread, k);
if (!i_am_first) {
SystemDictionaryShared::warn_excluded(k, "Duplicated unregistered class");
SystemDictionaryShared::set_excluded_locked(k);
}
}
}
};
// Returns true if the class should be excluded. This can be called by
// AOTConstantPoolResolver before or after we enter the CDS safepoint.
// When called before the safepoint, we need to link the class so that
// it can be checked by check_for_exclusion().
bool SystemDictionaryShared::should_be_excluded(Klass* k) {
assert(CDSConfig::is_dumping_archive(), "sanity");
assert(CDSConfig::current_thread_is_vm_or_dumper(), "sanity");
if (k->is_objArray_klass()) {
return should_be_excluded(ObjArrayKlass::cast(k)->bottom_klass());
}
if (!k->is_instance_klass()) {
return false;
} else {
InstanceKlass* ik = InstanceKlass::cast(k);
if (CDSConfig::is_dumping_dynamic_archive() && ik->is_shared()) {
// ik is already part of the static archive, so it will never be considered as excluded.
return false;
}
if (!SafepointSynchronize::is_at_safepoint()) {
if (!ik->is_linked()) {
// check_for_exclusion() below doesn't link unlinked classes. We come
// here only when we are trying to aot-link constant pool entries, so
// we'd better link the class.
JavaThread* THREAD = JavaThread::current();
ik->link_class(THREAD);
if (HAS_PENDING_EXCEPTION) {
CLEAR_PENDING_EXCEPTION;
return true; // linking failed -- let's exclude it
}
}
MutexLocker ml(DumpTimeTable_lock, Mutex::_no_safepoint_check_flag);
DumpTimeClassInfo* p = get_info_locked(ik);
if (p->is_excluded()) {
return true;
}
return check_for_exclusion(ik, p);
} else {
// No need to check for is_linked() as all eligible classes should have
// already been linked in MetaspaceShared::link_class_for_cds().
// Can't take the lock as we are in safepoint.
DumpTimeClassInfo* p = _dumptime_table->get(ik);
if (p->is_excluded()) {
return true;
}
return check_for_exclusion(ik, p);
}
}
}
void SystemDictionaryShared::finish_exclusion_checks() {
if (CDSConfig::is_dumping_dynamic_archive() || CDSConfig::is_dumping_preimage_static_archive()) {
// Do this first -- if a base class is excluded due to duplication,
// all of its subclasses will also be excluded.
ResourceMark rm;
UnregisteredClassesDuplicationChecker dup_checker;
_dumptime_table->iterate_all_live_classes(&dup_checker);
dup_checker.mark_duplicated_classes();
}
_dumptime_table->iterate_all_live_classes([&] (InstanceKlass* k, DumpTimeClassInfo& info) {
SystemDictionaryShared::check_for_exclusion(k, &info);
});
_dumptime_table->update_counts();
if (CDSConfig::is_dumping_lambdas_in_legacy_mode()) {
LambdaProxyClassDictionary::cleanup_dumptime_table();
}
}
bool SystemDictionaryShared::is_excluded_class(InstanceKlass* k) {
assert(!class_loading_may_happen(), "class loading must be disabled");
assert_lock_strong(DumpTimeTable_lock);
assert(CDSConfig::is_dumping_archive(), "sanity");
DumpTimeClassInfo* p = get_info_locked(k);
return p->is_excluded();
}
void SystemDictionaryShared::set_excluded_locked(InstanceKlass* k) {
assert_lock_strong(DumpTimeTable_lock);
assert(CDSConfig::is_dumping_archive(), "sanity");
DumpTimeClassInfo* info = get_info_locked(k);
info->set_excluded();
}
void SystemDictionaryShared::set_excluded(InstanceKlass* k) {
assert(CDSConfig::is_dumping_archive(), "sanity");
DumpTimeClassInfo* info = get_info(k);
info->set_excluded();
}
void SystemDictionaryShared::set_class_has_failed_verification(InstanceKlass* ik) {
assert(CDSConfig::is_dumping_archive(), "sanity");
DumpTimeClassInfo* p = get_info(ik);
p->set_failed_verification();
}
bool SystemDictionaryShared::has_class_failed_verification(InstanceKlass* ik) {
assert(CDSConfig::is_dumping_archive(), "sanity");
DumpTimeClassInfo* p = _dumptime_table->get(ik);
return (p == nullptr) ? false : p->failed_verification();
}
void SystemDictionaryShared::set_from_class_file_load_hook(InstanceKlass* ik) {
warn_excluded(ik, "From ClassFileLoadHook");
set_excluded(ik);
}
void SystemDictionaryShared::dumptime_classes_do(MetaspaceClosure* it) {
assert_lock_strong(DumpTimeTable_lock);
auto do_klass = [&] (InstanceKlass* k, DumpTimeClassInfo& info) {
if (CDSConfig::is_dumping_final_static_archive() && !k->is_loaded()) {
assert(k->defined_by_other_loaders(), "must be");
info.metaspace_pointers_do(it);
} else if (k->is_loader_alive() && !info.is_excluded()) {
info.metaspace_pointers_do(it);
}
};
_dumptime_table->iterate_all_live_classes(do_klass);
if (CDSConfig::is_dumping_lambdas_in_legacy_mode()) {
LambdaProxyClassDictionary::dumptime_classes_do(it);
}
}
// Called from VerificationType::is_reference_assignable_from() before performing the assignability check of
// T1 must be assignable from T2
// Where:
// L is the class loader of <k>
// T1 is the type resolved by L using the name <name>
// T2 is the type resolved by L using the name <from_name>
//
// The meaning of (*skip_assignability_check):
// true: is_reference_assignable_from() should SKIP the assignability check
// false: is_reference_assignable_from() should COMPLETE the assignability check
void SystemDictionaryShared::add_verification_constraint(InstanceKlass* k, Symbol* name,
Symbol* from_name, bool from_field_is_protected, bool from_is_array, bool from_is_object,
bool* skip_assignability_check) {
assert(CDSConfig::is_dumping_archive(), "sanity");
DumpTimeClassInfo* info = get_info(k);
info->add_verification_constraint(k, name, from_name, from_field_is_protected,
from_is_array, from_is_object);
if (CDSConfig::is_dumping_classic_static_archive() && !is_builtin(k)) {
// This applies ONLY to the "classic" CDS static dump, which reads the list of
// unregistered classes (those intended for custom class loaders) from the classlist
// and loads them using jdk.internal.misc.CDS$UnregisteredClassLoader.
//
// When the classlist contains an unregistered class k, the supertypes of k are also
// recorded in the classlist. However, the classlist does not contain information about
// any class X that's not a supertype of k but is needed in the verification of k.
// As a result, CDS$UnregisteredClassLoader will not know how to resolve X.
//
// Therefore, we tell the verifier to refrain from resolving X. Instead, X is recorded
// (symbolically) in the verification constraints of k. In the production run,
// when k is loaded, we will go through its verification constraints and resolve X to complete
// the is_reference_assignable_from() checks.
*skip_assignability_check = true;
} else {
// In all other cases, we are using an *actual* class loader to load k, so it should be able
// to resolve any types that are needed for the verification of k.
*skip_assignability_check = false;
}
}
void SystemDictionaryShared::add_enum_klass_static_field(InstanceKlass* ik, int root_index) {
assert(CDSConfig::is_dumping_heap(), "sanity");
DumpTimeClassInfo* info = get_info_locked(ik);
info->add_enum_klass_static_field(root_index);
}
void SystemDictionaryShared::check_verification_constraints(InstanceKlass* klass,
TRAPS) {
assert(CDSConfig::is_using_archive(), "called at run time with CDS enabled only");
RunTimeClassInfo* record = RunTimeClassInfo::get_for(klass);
int length = record->num_verifier_constraints();
if (length > 0) {
for (int i = 0; i < length; i++) {
RunTimeClassInfo::RTVerifierConstraint* vc = record->verifier_constraint_at(i);
Symbol* name = vc->name();
Symbol* from_name = vc->from_name();
if (log_is_enabled(Trace, aot, verification)) {
ResourceMark rm(THREAD);
log_trace(aot, verification)("check_verification_constraint: %s: %s must be subclass of %s [0x%x]",
klass->external_name(), from_name->as_klass_external_name(),
name->as_klass_external_name(), record->verifier_constraint_flag(i));
}
bool ok = VerificationType::resolve_and_check_assignability(klass, name, from_name,
record->from_field_is_protected(i), record->from_is_array(i), record->from_is_object(i), CHECK);
if (!ok) {
ResourceMark rm(THREAD);
stringStream ss;
ss.print_cr("Bad type on operand stack");
ss.print_cr("Exception Details:");
ss.print_cr(" Location:\n %s", klass->name()->as_C_string());
ss.print_cr(" Reason:\n Type '%s' is not assignable to '%s'",
from_name->as_quoted_ascii(), name->as_quoted_ascii());
THROW_MSG(vmSymbols::java_lang_VerifyError(), ss.as_string());
}
}
}
}
void SystemDictionaryShared::copy_verification_constraints_from_preimage(InstanceKlass* klass) {
assert(CDSConfig::is_using_archive(), "called at run time with CDS enabled only");
DumpTimeClassInfo* dt_info = get_info(klass);
RunTimeClassInfo* rt_info = RunTimeClassInfo::get_for(klass); // from preimage
int length = rt_info->num_verifier_constraints();
if (length > 0) {
for (int i = 0; i < length; i++) {
RunTimeClassInfo::RTVerifierConstraint* vc = rt_info->verifier_constraint_at(i);
Symbol* name = vc->name();
Symbol* from_name = vc->from_name();
dt_info->add_verification_constraint(klass, name, from_name,
rt_info->from_field_is_protected(i), rt_info->from_is_array(i), rt_info->from_is_object(i));
}
}
}
static oop get_class_loader_by(char type) {
if (type == (char)ClassLoader::BOOT_LOADER) {
return (oop)nullptr;
} else if (type == (char)ClassLoader::PLATFORM_LOADER) {
return SystemDictionary::java_platform_loader();
} else {
assert (type == (char)ClassLoader::APP_LOADER, "Sanity");
return SystemDictionary::java_system_loader();
}
}
// Record class loader constraints that are checked inside
// InstanceKlass::link_class(), so that these can be checked quickly
// at runtime without laying out the vtable/itables.
void SystemDictionaryShared::record_linking_constraint(Symbol* name, InstanceKlass* klass,
Handle loader1, Handle loader2) {
// A linking constraint check is executed when:
// - klass extends or implements type S
// - klass overrides method S.M(...) with X.M
// - If klass defines the method M, X is
// the same as klass.
// - If klass does not define the method M,
// X must be a supertype of klass and X.M is
// a default method defined by X.
// - loader1 = X->class_loader()
// - loader2 = S->class_loader()
// - loader1 != loader2
// - M's parameter(s) include an object type T
// We require that
// - whenever loader1 and loader2 try to
// resolve the type T, they must always resolve to
// the same InstanceKlass.
// NOTE: type T may or may not be currently resolved in
// either of these two loaders. The check itself does not
// try to resolve T.
oop klass_loader = klass->class_loader();
if (!is_system_class_loader(klass_loader) &&
!is_platform_class_loader(klass_loader)) {
// If klass is loaded by system/platform loaders, we can
// guarantee that klass and S must be loaded by the same
// respective loader between dump time and run time, and
// the exact same check on (name, loader1, loader2) will
// be executed. Hence, we can cache this check and execute
// it at runtime without walking the vtable/itables.
//
// This cannot be guaranteed for classes loaded by other
// loaders, so we bail.
return;
}
assert(is_builtin(klass), "must be");
assert(klass_loader != nullptr, "should not be called for boot loader");
assert(loader1 != loader2, "must be");
if (CDSConfig::is_dumping_dynamic_archive() && Thread::current()->is_VM_thread()) {
// We are re-laying out the vtable/itables of the *copy* of
// a class during the final stage of dynamic dumping. The
// linking constraints for this class has already been recorded.
return;
}
assert(!Thread::current()->is_VM_thread(), "must be");
assert(CDSConfig::is_dumping_archive(), "sanity");
DumpTimeClassInfo* info = get_info(klass);
info->record_linking_constraint(name, loader1, loader2);
}
// returns true IFF there's no need to re-initialize the i/v-tables for klass for
// the purpose of checking class loader constraints.
bool SystemDictionaryShared::check_linking_constraints(Thread* current, InstanceKlass* klass) {
assert(CDSConfig::is_using_archive(), "called at run time with CDS enabled only");
LogTarget(Info, class, loader, constraints) log;
if (klass->defined_by_boot_loader()) {
// No class loader constraint check performed for boot classes.
return true;
}
if (klass->defined_by_platform_loader() || klass->defined_by_app_loader()) {
RunTimeClassInfo* info = RunTimeClassInfo::get_for(klass);
assert(info != nullptr, "Sanity");
if (info->num_loader_constraints() > 0) {
HandleMark hm(current);
for (int i = 0; i < info->num_loader_constraints(); i++) {
RunTimeClassInfo::RTLoaderConstraint* lc = info->loader_constraint_at(i);
Symbol* name = lc->constraint_name();
Handle loader1(current, get_class_loader_by(lc->_loader_type1));
Handle loader2(current, get_class_loader_by(lc->_loader_type2));
if (log.is_enabled()) {
ResourceMark rm(current);
log.print("[CDS add loader constraint for class %s symbol %s loader[0] %s loader[1] %s",
klass->external_name(), name->as_C_string(),
ClassLoaderData::class_loader_data(loader1())->loader_name_and_id(),
ClassLoaderData::class_loader_data(loader2())->loader_name_and_id());
}
if (!SystemDictionary::add_loader_constraint(name, klass, loader1, loader2)) {
// Loader constraint violation has been found. The caller
// will re-layout the vtable/itables to produce the correct
// exception.
if (log.is_enabled()) {
log.print(" failed]");
}
return false;
}
if (log.is_enabled()) {
log.print(" succeeded]");
}
}
return true; // for all recorded constraints added successfully.
}
}
if (log.is_enabled()) {
ResourceMark rm(current);
log.print("[CDS has not recorded loader constraint for class %s]", klass->external_name());
}
return false;
}
void SystemDictionaryShared::copy_linking_constraints_from_preimage(InstanceKlass* klass) {
assert(CDSConfig::is_using_archive(), "called at run time with CDS enabled only");
JavaThread* current = JavaThread::current();
if (klass->defined_by_platform_loader() || klass->defined_by_app_loader()) {
RunTimeClassInfo* rt_info = RunTimeClassInfo::get_for(klass); // from preimage
if (rt_info->num_loader_constraints() > 0) {
for (int i = 0; i < rt_info->num_loader_constraints(); i++) {
RunTimeClassInfo::RTLoaderConstraint* lc = rt_info->loader_constraint_at(i);
Symbol* name = lc->constraint_name();
Handle loader1(current, get_class_loader_by(lc->_loader_type1));
Handle loader2(current, get_class_loader_by(lc->_loader_type2));
record_linking_constraint(name, klass, loader1, loader2);
}
}
}
}
unsigned int SystemDictionaryShared::hash_for_shared_dictionary(address ptr) {
if (ArchiveBuilder::is_active() && ArchiveBuilder::current()->is_in_buffer_space(ptr)) {
uintx offset = ArchiveBuilder::current()->any_to_offset(ptr);
unsigned int hash = primitive_hash<uintx>(offset);
DEBUG_ONLY({
if (MetaspaceObj::is_shared((const MetaspaceObj*)ptr)) {
assert(hash == SystemDictionaryShared::hash_for_shared_dictionary_quick(ptr), "must be");
}
});
return hash;
} else {
return SystemDictionaryShared::hash_for_shared_dictionary_quick(ptr);
}
}
class CopySharedClassInfoToArchive : StackObj {
CompactHashtableWriter* _writer;
bool _is_builtin;
ArchiveBuilder *_builder;
public:
CopySharedClassInfoToArchive(CompactHashtableWriter* writer,
bool is_builtin)
: _writer(writer), _is_builtin(is_builtin), _builder(ArchiveBuilder::current()) {}
void do_entry(InstanceKlass* k, DumpTimeClassInfo& info) {
if (!info.is_excluded() && info.is_builtin() == _is_builtin) {
size_t byte_size = info.runtime_info_bytesize();
RunTimeClassInfo* record;
record = (RunTimeClassInfo*)ArchiveBuilder::ro_region_alloc(byte_size);
record->init(info);
unsigned int hash;
Symbol* name = info._klass->name();
name = ArchiveBuilder::current()->get_buffered_addr(name);
hash = SystemDictionaryShared::hash_for_shared_dictionary((address)name);
u4 delta = _builder->buffer_to_offset_u4((address)record);
if (_is_builtin && info._klass->is_hidden()) {
// skip
} else {
_writer->add(hash, delta);
}
if (log_is_enabled(Trace, aot, hashtables)) {
ResourceMark rm;
log_trace(aot, hashtables)("%s dictionary: %s", (_is_builtin ? "builtin" : "unregistered"), info._klass->external_name());
}
// Save this for quick runtime lookup of InstanceKlass* -> RunTimeClassInfo*
InstanceKlass* buffered_klass = ArchiveBuilder::current()->get_buffered_addr(info._klass);
RunTimeClassInfo::set_for(buffered_klass, record);
}
}
};
void SystemDictionaryShared::write_dictionary(RunTimeSharedDictionary* dictionary,
bool is_builtin) {
CompactHashtableStats stats;
dictionary->reset();
CompactHashtableWriter writer(_dumptime_table->count_of(is_builtin), &stats);
CopySharedClassInfoToArchive copy(&writer, is_builtin);
assert_lock_strong(DumpTimeTable_lock);
_dumptime_table->iterate_all_live_classes(&copy);
writer.dump(dictionary, is_builtin ? "builtin dictionary" : "unregistered dictionary");
}
void SystemDictionaryShared::write_to_archive(bool is_static_archive) {
ArchiveInfo* archive = get_archive(is_static_archive);
write_dictionary(&archive->_builtin_dictionary, true);
write_dictionary(&archive->_unregistered_dictionary, false);
if (CDSConfig::is_dumping_lambdas_in_legacy_mode()) {
LambdaProxyClassDictionary::write_dictionary(is_static_archive);
} else {
LambdaProxyClassDictionary::reset_dictionary(is_static_archive);
}
}
void SystemDictionaryShared::serialize_dictionary_headers(SerializeClosure* soc,
bool is_static_archive) {
ArchiveInfo* archive = get_archive(is_static_archive);
archive->_builtin_dictionary.serialize_header(soc);
archive->_unregistered_dictionary.serialize_header(soc);
LambdaProxyClassDictionary::serialize(soc, is_static_archive);
}
void SystemDictionaryShared::serialize_vm_classes(SerializeClosure* soc) {
for (auto id : EnumRange<vmClassID>{}) {
soc->do_ptr(vmClasses::klass_addr_at(id));
}
}
const RunTimeClassInfo*
SystemDictionaryShared::find_record(RunTimeSharedDictionary* static_dict, RunTimeSharedDictionary* dynamic_dict, Symbol* name) {
if (!CDSConfig::is_using_archive() || !name->is_shared()) {
// The names of all shared classes must also be a shared Symbol.
return nullptr;
}
unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(name);
const RunTimeClassInfo* record = nullptr;
if (DynamicArchive::is_mapped()) {
// Use the regenerated holder classes in the dynamic archive as they
// have more methods than those in the base archive.
if (LambdaFormInvokers::may_be_regenerated_class(name)) {
record = dynamic_dict->lookup(name, hash, 0);
if (record != nullptr) {
return record;
}
}
}
if (!MetaspaceShared::is_shared_dynamic(name)) {
// The names of all shared classes in the static dict must also be in the
// static archive
record = static_dict->lookup(name, hash, 0);
}
if (record == nullptr && DynamicArchive::is_mapped()) {
record = dynamic_dict->lookup(name, hash, 0);
}
return record;
}
InstanceKlass* SystemDictionaryShared::find_builtin_class(Symbol* name) {
const RunTimeClassInfo* record = find_record(&_static_archive._builtin_dictionary,
&_dynamic_archive._builtin_dictionary,
name);
if (record != nullptr) {
assert(!record->klass()->is_hidden(), "hidden class cannot be looked up by name");
DEBUG_ONLY(check_klass_after_loading(record->klass());)
// We did not save the classfile data of the generated LambdaForm invoker classes,
// so we cannot support CLFH for such classes.
if (record->klass()->is_generated_shared_class() && JvmtiExport::should_post_class_file_load_hook()) {
return nullptr;
}
return record->klass();
} else {
return nullptr;
}
}
void SystemDictionaryShared::update_shared_entry(InstanceKlass* k, int id) {
assert(CDSConfig::is_dumping_static_archive(), "class ID is used only for static dump (from classlist)");
DumpTimeClassInfo* info = get_info(k);
info->_id = id;
}
const char* SystemDictionaryShared::loader_type_for_shared_class(Klass* k) {
assert(k != nullptr, "Sanity");
assert(k->is_shared(), "Must be");
assert(k->is_instance_klass(), "Must be");
InstanceKlass* ik = InstanceKlass::cast(k);
if (ik->defined_by_boot_loader()) {
return "boot_loader";
} else if (ik->defined_by_platform_loader()) {
return "platform_loader";
} else if (ik->defined_by_app_loader()) {
return "app_loader";
} else if (ik->defined_by_other_loaders()) {
return "unregistered_loader";
} else {
return "unknown loader";
}
}
class SharedDictionaryPrinter : StackObj {
outputStream* _st;
int _index;
public:
SharedDictionaryPrinter(outputStream* st) : _st(st), _index(0) {}
void do_value(const RunTimeClassInfo* record) {
ResourceMark rm;
_st->print_cr("%4d: %s %s", _index++, record->klass()->external_name(),
SystemDictionaryShared::loader_type_for_shared_class(record->klass()));
if (record->klass()->array_klasses() != nullptr) {
record->klass()->array_klasses()->cds_print_value_on(_st);
_st->cr();
}
}
int index() const { return _index; }
};
void SystemDictionaryShared::ArchiveInfo::print_on(const char* prefix,
outputStream* st,
bool is_static_archive) {
st->print_cr("%sShared Dictionary", prefix);
SharedDictionaryPrinter p(st);
st->print_cr("%sShared Builtin Dictionary", prefix);
_builtin_dictionary.iterate(&p);
st->print_cr("%sShared Unregistered Dictionary", prefix);
_unregistered_dictionary.iterate(&p);
LambdaProxyClassDictionary::print_on(prefix, st, p.index(), is_static_archive);
}
void SystemDictionaryShared::ArchiveInfo::print_table_statistics(const char* prefix,
outputStream* st,
bool is_static_archive) {
st->print_cr("%sArchve Statistics", prefix);
_builtin_dictionary.print_table_statistics(st, "Builtin Shared Dictionary");
_unregistered_dictionary.print_table_statistics(st, "Unregistered Shared Dictionary");
LambdaProxyClassDictionary::print_statistics(st, is_static_archive);
}
void SystemDictionaryShared::print_shared_archive(outputStream* st, bool is_static) {
if (CDSConfig::is_using_archive()) {
if (is_static) {
_static_archive.print_on("", st, true);
} else {
if (DynamicArchive::is_mapped()) {
_dynamic_archive.print_on("Dynamic ", st, false);
}
}
}
}
void SystemDictionaryShared::print_on(outputStream* st) {
print_shared_archive(st, true);
print_shared_archive(st, false);
}
void SystemDictionaryShared::print_table_statistics(outputStream* st) {
if (CDSConfig::is_using_archive()) {
_static_archive.print_table_statistics("Static ", st, true);
if (DynamicArchive::is_mapped()) {
_dynamic_archive.print_table_statistics("Dynamic ", st, false);
}
}
}
bool SystemDictionaryShared::is_dumptime_table_empty() {
assert_lock_strong(DumpTimeTable_lock);
_dumptime_table->update_counts();
if (_dumptime_table->count_of(true) == 0 && _dumptime_table->count_of(false) == 0){
return true;
}
return false;
}