/* * Copyright (c) 1997, 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/aotMetaspace.hpp" #include "cds/cdsConfig.hpp" #include "classfile/javaClasses.hpp" #include "classfile/moduleEntry.hpp" #include "classfile/vmClasses.hpp" #include "classfile/vmSymbols.hpp" #include "gc/shared/collectedHeap.inline.hpp" #include "jvmtifiles/jvmti.h" #include "memory/metaspaceClosure.hpp" #include "memory/resourceArea.hpp" #include "memory/universe.hpp" #include "oops/arrayKlass.inline.hpp" #include "oops/arrayOop.hpp" #include "oops/instanceKlass.hpp" #include "oops/klass.inline.hpp" #include "oops/objArrayOop.hpp" #include "oops/oop.inline.hpp" #include "runtime/handles.inline.hpp" void* ArrayKlass::operator new(size_t size, ClassLoaderData* loader_data, size_t word_size, TRAPS) throw() { return Metaspace::allocate(loader_data, word_size, MetaspaceObj::ClassType, true, THREAD); } ArrayKlass::ArrayKlass() { assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS"); } int ArrayKlass::static_size(int header_size) { // size of an array klass object assert(header_size <= InstanceKlass::header_size(), "bad header size"); // If this assert fails, see comments in base_create_array_klass. header_size = InstanceKlass::header_size(); int vtable_len = Universe::base_vtable_size(); int size = header_size + vtable_len; return align_metadata_size(size); } InstanceKlass* ArrayKlass::java_super() const { if (super() == nullptr) return nullptr; // bootstrap case // Array klasses have primary supertypes which are not reported to Java. // Example super chain: String[][] -> Object[][] -> Object[] -> Object return vmClasses::Object_klass(); } oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { ShouldNotReachHere(); return nullptr; } // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { // There are no fields in an array klass but look to the super class (Object) assert(super(), "super klass must be present"); return super()->find_field(name, sig, fd); } Method* ArrayKlass::uncached_lookup_method(const Symbol* name, const Symbol* signature, OverpassLookupMode overpass_mode, PrivateLookupMode private_mode) const { // There are no methods in an array klass but the super class (Object) has some assert(super(), "super klass must be present"); // Always ignore overpass methods in superclasses, although technically the // super klass of an array, (j.l.Object) should not have // any overpass methods present. return super()->uncached_lookup_method(name, signature, OverpassLookupMode::skip, private_mode); } ArrayKlass::ArrayKlass(Symbol* name, KlassKind kind) : Klass(kind), _dimension(1), _higher_dimension(nullptr), _lower_dimension(nullptr) { // Arrays don't add any new methods, so their vtable is the same size as // the vtable of klass Object. set_vtable_length(Universe::base_vtable_size()); set_name(name); set_super(Universe::is_bootstrapping() ? nullptr : vmClasses::Object_klass()); set_layout_helper(Klass::_lh_neutral_value); set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5) JFR_ONLY(INIT_ID(this);) log_array_class_load(this); } // Initialization of vtables and mirror object is done separately from base_create_array_klass, // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup. void ArrayKlass::complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module_entry, TRAPS) { k->initialize_supers(super_klass, nullptr, CHECK); k->vtable().initialize_vtable(); // During bootstrapping, before java.base is defined, the module_entry may not be present yet. // These classes will be put on a fixup list and their module fields will be patched once // java.base is defined. assert((module_entry != nullptr) || ((module_entry == nullptr) && !ModuleEntryTable::javabase_defined()), "module entry not available post " JAVA_BASE_NAME " definition"); oop module_oop = (module_entry != nullptr) ? module_entry->module_oop() : (oop)nullptr; java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(THREAD, module_oop), Handle(), Handle(), CHECK); } ArrayKlass* ArrayKlass::array_klass(int n, TRAPS) { assert(dimension() <= n, "check order of chain"); int dim = dimension(); if (dim == n) return this; // lock-free read needs acquire semantics if (higher_dimension_acquire() == nullptr) { // Ensure atomic creation of higher dimensions RecursiveLocker rl(MultiArray_lock, THREAD); if (higher_dimension() == nullptr) { // Create multi-dim klass object and link them together ObjArrayKlass* ak = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL); // use 'release' to pair with lock-free load release_set_higher_dimension(ak); assert(ak->lower_dimension() == this, "lower dimension mismatch"); } } ObjArrayKlass* ak = higher_dimension(); assert(ak != nullptr, "should be set"); THREAD->check_possible_safepoint(); return ak->array_klass(n, THREAD); } ArrayKlass* ArrayKlass::array_klass_or_null(int n) { assert(dimension() <= n, "check order of chain"); int dim = dimension(); if (dim == n) return this; // lock-free read needs acquire semantics if (higher_dimension_acquire() == nullptr) { return nullptr; } ObjArrayKlass *ak = higher_dimension(); return ak->array_klass_or_null(n); } ArrayKlass* ArrayKlass::array_klass(TRAPS) { return array_klass(dimension() + 1, THREAD); } ArrayKlass* ArrayKlass::array_klass_or_null() { return array_klass_or_null(dimension() + 1); } GrowableArray* ArrayKlass::compute_secondary_supers(int num_extra_slots, Array* transitive_interfaces) { // interfaces = { cloneable_klass, serializable_klass }; assert(num_extra_slots == 0, "sanity of primitive array type"); assert(transitive_interfaces == nullptr, "sanity"); // Must share this for correct bootstrapping! set_secondary_supers(Universe::the_array_interfaces_array(), Universe::the_array_interfaces_bitmap()); return nullptr; } objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) { check_array_allocation_length(length, arrayOopDesc::max_array_length(T_ARRAY), CHECK_NULL); size_t size = objArrayOopDesc::object_size(length); ArrayKlass* ak = array_klass(n + dimension(), CHECK_NULL); objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length, /* do_zero */ true, CHECK_NULL); // initialization to null not necessary, area already cleared return o; } // JVMTI support jint ArrayKlass::jvmti_class_status() const { return JVMTI_CLASS_STATUS_ARRAY; } void ArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) { Klass::metaspace_pointers_do(it); ResourceMark rm; log_trace(aot)("Iter(ArrayKlass): %p (%s)", this, external_name()); // need to cast away volatile it->push((Klass**)&_higher_dimension); it->push((Klass**)&_lower_dimension); } #if INCLUDE_CDS void ArrayKlass::remove_unshareable_info() { Klass::remove_unshareable_info(); if (_higher_dimension != nullptr) { ArrayKlass *ak = higher_dimension(); ak->remove_unshareable_info(); } } void ArrayKlass::remove_java_mirror() { Klass::remove_java_mirror(); if (_higher_dimension != nullptr) { ArrayKlass *ak = higher_dimension(); ak->remove_java_mirror(); } } void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { Klass::restore_unshareable_info(loader_data, protection_domain, CHECK); // Klass recreates the component mirror also if (_higher_dimension != nullptr) { ArrayKlass *ak = higher_dimension(); log_array_class_load(ak); ak->restore_unshareable_info(loader_data, protection_domain, CHECK); } } void ArrayKlass::cds_print_value_on(outputStream* st) const { assert(is_klass(), "must be klass"); st->print(" - array: %s", internal_name()); if (_higher_dimension != nullptr) { ArrayKlass* ak = higher_dimension(); st->cr(); ak->cds_print_value_on(st); } } #endif // INCLUDE_CDS void ArrayKlass::log_array_class_load(Klass* k) { LogTarget(Debug, class, load, array) lt; if (lt.is_enabled()) { LogStream ls(lt); ResourceMark rm; ls.print("%s", k->name()->as_klass_external_name()); if (AOTMetaspace::in_aot_cache_dynamic_region((void*)k)) { ls.print(" source: shared objects file (top)"); } else if (AOTMetaspace::in_aot_cache_static_region((void*)k)) { ls.print(" source: shared objects file"); } ls.cr(); } } // Printing void ArrayKlass::print_on(outputStream* st) const { assert(is_klass(), "must be klass"); Klass::print_on(st); } void ArrayKlass::print_value_on(outputStream* st) const { assert(is_klass(), "must be klass"); for(int index = 0; index < dimension(); index++) { st->print("[]"); } } void ArrayKlass::oop_print_on(oop obj, outputStream* st) { assert(obj->is_array(), "must be array"); Klass::oop_print_on(obj, st); st->print_cr(" - length: %d", arrayOop(obj)->length()); } // Verification void ArrayKlass::verify_on(outputStream* st) { Klass::verify_on(st); } void ArrayKlass::oop_verify_on(oop obj, outputStream* st) { guarantee(obj->is_array(), "must be array"); arrayOop a = arrayOop(obj); guarantee(a->length() >= 0, "array with negative length?"); }