1 /* 2 * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/javaClasses.hpp" 27 #include "classfile/moduleEntry.hpp" 28 #include "classfile/vmClasses.hpp" 29 #include "classfile/vmSymbols.hpp" 30 #include "gc/shared/collectedHeap.inline.hpp" 31 #include "jvmtifiles/jvmti.h" 32 #include "memory/metaspaceClosure.hpp" 33 #include "memory/resourceArea.hpp" 34 #include "memory/universe.hpp" 35 #include "oops/arrayKlass.hpp" 36 #include "oops/arrayOop.hpp" 37 #include "oops/instanceKlass.hpp" 38 #include "oops/klass.inline.hpp" 39 #include "oops/objArrayOop.hpp" 40 #include "oops/oop.inline.hpp" 41 #include "runtime/handles.inline.hpp" 42 43 int ArrayKlass::static_size(int header_size) { 44 // size of an array klass object 45 assert(header_size <= InstanceKlass::header_size(), "bad header size"); 46 // If this assert fails, see comments in base_create_array_klass. 47 header_size = InstanceKlass::header_size(); 48 int vtable_len = Universe::base_vtable_size(); 49 int size = header_size + vtable_len; 50 return align_metadata_size(size); 51 } 52 53 54 InstanceKlass* ArrayKlass::java_super() const { 55 if (super() == NULL) return NULL; // bootstrap case 56 // Array klasses have primary supertypes which are not reported to Java. 57 // Example super chain: String[][] -> Object[][] -> Object[] -> Object 58 return vmClasses::Object_klass(); 59 } 60 61 62 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 63 ShouldNotReachHere(); 64 return NULL; 65 } 66 67 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined 68 Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 69 // There are no fields in an array klass but look to the super class (Object) 70 assert(super(), "super klass must be present"); 71 return super()->find_field(name, sig, fd); 72 } 73 74 Method* ArrayKlass::uncached_lookup_method(const Symbol* name, 75 const Symbol* signature, 76 OverpassLookupMode overpass_mode, 77 PrivateLookupMode private_mode) const { 78 // There are no methods in an array klass but the super class (Object) has some 79 assert(super(), "super klass must be present"); 80 // Always ignore overpass methods in superclasses, although technically the 81 // super klass of an array, (j.l.Object) should not have 82 // any overpass methods present. 83 return super()->uncached_lookup_method(name, signature, OverpassLookupMode::skip, private_mode); 84 } 85 86 ArrayKlass::ArrayKlass(Symbol* name, KlassID id) : 87 Klass(id), 88 _dimension(1), 89 _higher_dimension(NULL), 90 _lower_dimension(NULL) { 91 // Arrays don't add any new methods, so their vtable is the same size as 92 // the vtable of klass Object. 93 set_vtable_length(Universe::base_vtable_size()); 94 set_name(name); 95 set_super(Universe::is_bootstrapping() ? NULL : vmClasses::Object_klass()); 96 set_layout_helper(Klass::_lh_neutral_value); 97 set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5) 98 JFR_ONLY(INIT_ID(this);) 99 } 100 101 102 // Initialization of vtables and mirror object is done separatly from base_create_array_klass, 103 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup. 104 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module_entry, TRAPS) { 105 k->initialize_supers(super_klass, NULL, CHECK); 106 k->vtable().initialize_vtable(); 107 108 // During bootstrapping, before java.base is defined, the module_entry may not be present yet. 109 // These classes will be put on a fixup list and their module fields will be patched once 110 // java.base is defined. 111 assert((module_entry != NULL) || ((module_entry == NULL) && !ModuleEntryTable::javabase_defined()), 112 "module entry not available post " JAVA_BASE_NAME " definition"); 113 oop module = (module_entry != NULL) ? module_entry->module() : (oop)NULL; 114 java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(THREAD, module), Handle(), Handle(), CHECK); 115 } 116 117 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots, 118 Array<InstanceKlass*>* transitive_interfaces) { 119 // interfaces = { cloneable_klass, serializable_klass }; 120 assert(num_extra_slots == 0, "sanity of primitive array type"); 121 assert(transitive_interfaces == NULL, "sanity"); 122 // Must share this for correct bootstrapping! 123 set_secondary_supers(Universe::the_array_interfaces_array()); 124 return NULL; 125 } 126 127 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) { 128 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_ARRAY), CHECK_NULL); 129 size_t size = objArrayOopDesc::object_size(length); 130 Klass* k = array_klass(n+dimension(), CHECK_NULL); 131 ArrayKlass* ak = ArrayKlass::cast(k); 132 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length, 133 /* do_zero */ true, CHECK_NULL); 134 // initialization to NULL not necessary, area already cleared 135 return o; 136 } 137 138 jint ArrayKlass::compute_modifier_flags() const { 139 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 140 } 141 142 // JVMTI support 143 144 jint ArrayKlass::jvmti_class_status() const { 145 return JVMTI_CLASS_STATUS_ARRAY; 146 } 147 148 void ArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) { 149 Klass::metaspace_pointers_do(it); 150 151 ResourceMark rm; 152 log_trace(cds)("Iter(ArrayKlass): %p (%s)", this, external_name()); 153 154 // need to cast away volatile 155 it->push((Klass**)&_higher_dimension); 156 it->push((Klass**)&_lower_dimension); 157 } 158 159 void ArrayKlass::remove_unshareable_info() { 160 Klass::remove_unshareable_info(); 161 if (_higher_dimension != NULL) { 162 ArrayKlass *ak = ArrayKlass::cast(higher_dimension()); 163 ak->remove_unshareable_info(); 164 } 165 } 166 167 void ArrayKlass::remove_java_mirror() { 168 Klass::remove_java_mirror(); 169 if (_higher_dimension != NULL) { 170 ArrayKlass *ak = ArrayKlass::cast(higher_dimension()); 171 ak->remove_java_mirror(); 172 } 173 } 174 175 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 176 assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader"); 177 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK); 178 // Klass recreates the component mirror also 179 180 if (_higher_dimension != NULL) { 181 ArrayKlass *ak = ArrayKlass::cast(higher_dimension()); 182 ak->restore_unshareable_info(loader_data, protection_domain, CHECK); 183 } 184 } 185 186 // Printing 187 188 void ArrayKlass::print_on(outputStream* st) const { 189 assert(is_klass(), "must be klass"); 190 Klass::print_on(st); 191 } 192 193 void ArrayKlass::print_value_on(outputStream* st) const { 194 assert(is_klass(), "must be klass"); 195 for(int index = 0; index < dimension(); index++) { 196 st->print("[]"); 197 } 198 } 199 200 void ArrayKlass::oop_print_on(oop obj, outputStream* st) { 201 assert(obj->is_array(), "must be array"); 202 Klass::oop_print_on(obj, st); 203 st->print_cr(" - length: %d", arrayOop(obj)->length()); 204 } 205 206 207 // Verification 208 209 void ArrayKlass::verify_on(outputStream* st) { 210 Klass::verify_on(st); 211 } 212 213 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) { 214 guarantee(obj->is_array(), "must be array"); 215 arrayOop a = arrayOop(obj); 216 guarantee(a->length() >= 0, "array with negative length?"); 217 }