1 /* 2 * Copyright (c) 1997, 2023, 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 "cds/metaspaceShared.hpp" 27 #include "classfile/javaClasses.hpp" 28 #include "classfile/moduleEntry.hpp" 29 #include "classfile/symbolTable.hpp" 30 #include "classfile/vmClasses.hpp" 31 #include "classfile/vmSymbols.hpp" 32 #include "gc/shared/collectedHeap.inline.hpp" 33 #include "jvmtifiles/jvmti.h" 34 #include "memory/metaspaceClosure.hpp" 35 #include "memory/resourceArea.hpp" 36 #include "memory/universe.hpp" 37 #include "oops/arrayKlass.hpp" 38 #include "oops/objArrayKlass.hpp" 39 #include "oops/arrayOop.hpp" 40 #include "oops/instanceKlass.hpp" 41 #include "oops/klass.inline.hpp" 42 #include "oops/objArrayOop.hpp" 43 #include "oops/oop.inline.hpp" 44 #include "runtime/handles.inline.hpp" 45 46 int ArrayKlass::static_size(int header_size) { 47 // size of an array klass object 48 assert(header_size <= InstanceKlass::header_size(), "bad header size"); 49 // If this assert fails, see comments in base_create_array_klass. 50 header_size = InstanceKlass::header_size(); 51 int vtable_len = Universe::base_vtable_size(); 52 int size = header_size + vtable_len; 53 return align_metadata_size(size); 54 } 55 56 57 InstanceKlass* ArrayKlass::java_super() const { 58 if (super() == nullptr) return nullptr; // bootstrap case 59 // Array klasses have primary supertypes which are not reported to Java. 60 // Example super chain: String[][] -> Object[][] -> Object[] -> Object 61 return vmClasses::Object_klass(); 62 } 63 64 65 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 66 ShouldNotReachHere(); 67 return nullptr; 68 } 69 70 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined 71 Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 72 // There are no fields in an array klass but look to the super class (Object) 73 assert(super(), "super klass must be present"); 74 return super()->find_field(name, sig, fd); 75 } 76 77 Method* ArrayKlass::uncached_lookup_method(const Symbol* name, 78 const Symbol* signature, 79 OverpassLookupMode overpass_mode, 80 PrivateLookupMode private_mode) const { 81 // There are no methods in an array klass but the super class (Object) has some 82 assert(super(), "super klass must be present"); 83 // Always ignore overpass methods in superclasses, although technically the 84 // super klass of an array, (j.l.Object) should not have 85 // any overpass methods present. 86 return super()->uncached_lookup_method(name, signature, OverpassLookupMode::skip, private_mode); 87 } 88 89 ArrayKlass::ArrayKlass(Symbol* name, KlassKind kind) : 90 Klass(kind), 91 _dimension(1), 92 _higher_dimension(nullptr), 93 _lower_dimension(nullptr) { 94 // Arrays don't add any new methods, so their vtable is the same size as 95 // the vtable of klass Object. 96 set_vtable_length(Universe::base_vtable_size()); 97 set_name(name); 98 set_super(Universe::is_bootstrapping() ? nullptr : vmClasses::Object_klass()); 99 set_layout_helper(Klass::_lh_neutral_value); 100 set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5) 101 JFR_ONLY(INIT_ID(this);) 102 log_array_class_load(this); 103 } 104 105 Symbol* ArrayKlass::create_element_klass_array_name(Klass* element_klass, bool qdesc, TRAPS) { 106 ResourceMark rm(THREAD); 107 Symbol* name = nullptr; 108 char *name_str = element_klass->name()->as_C_string(); 109 int len = element_klass->name()->utf8_length(); 110 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4); 111 int idx = 0; 112 new_str[idx++] = JVM_SIGNATURE_ARRAY; 113 if (element_klass->is_instance_klass()) { // it could be an array or simple type 114 if (qdesc) { 115 new_str[idx++] = JVM_SIGNATURE_PRIMITIVE_OBJECT; 116 } else { 117 new_str[idx++] = JVM_SIGNATURE_CLASS; 118 } 119 } 120 memcpy(&new_str[idx], name_str, len * sizeof(char)); 121 idx += len; 122 if (element_klass->is_instance_klass()) { 123 new_str[idx++] = JVM_SIGNATURE_ENDCLASS; 124 } 125 new_str[idx++] = '\0'; 126 return SymbolTable::new_symbol(new_str); 127 } 128 129 // Initialization of vtables and mirror object is done separately from base_create_array_klass, 130 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup. 131 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module_entry, TRAPS) { 132 k->initialize_supers(super_klass, nullptr, CHECK); 133 k->vtable().initialize_vtable(); 134 135 // During bootstrapping, before java.base is defined, the module_entry may not be present yet. 136 // These classes will be put on a fixup list and their module fields will be patched once 137 // java.base is defined. 138 assert((module_entry != nullptr) || ((module_entry == nullptr) && !ModuleEntryTable::javabase_defined()), 139 "module entry not available post " JAVA_BASE_NAME " definition"); 140 oop module = (module_entry != nullptr) ? module_entry->module() : (oop)nullptr; 141 java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(THREAD, module), Handle(), Handle(), CHECK); 142 } 143 144 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots, 145 Array<InstanceKlass*>* transitive_interfaces) { 146 // interfaces = { cloneable_klass, serializable_klass }; 147 assert(num_extra_slots == 0, "sanity of primitive array type"); 148 assert(transitive_interfaces == nullptr, "sanity"); 149 // Must share this for correct bootstrapping! 150 set_secondary_supers(Universe::the_array_interfaces_array()); 151 return nullptr; 152 } 153 154 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) { 155 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_ARRAY), CHECK_NULL); 156 size_t size = objArrayOopDesc::object_size(length); 157 ArrayKlass* ak = array_klass(n + dimension(), CHECK_NULL); 158 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length, 159 /* do_zero */ true, CHECK_NULL); 160 // initialization to null not necessary, area already cleared 161 return o; 162 } 163 164 oop ArrayKlass::component_mirror() const { 165 return java_lang_Class::component_mirror(java_mirror()); 166 } 167 168 jint ArrayKlass::compute_modifier_flags() const { 169 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 170 } 171 172 // JVMTI support 173 174 jint ArrayKlass::jvmti_class_status() const { 175 return JVMTI_CLASS_STATUS_ARRAY; 176 } 177 178 void ArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) { 179 Klass::metaspace_pointers_do(it); 180 181 ResourceMark rm; 182 log_trace(cds)("Iter(ArrayKlass): %p (%s)", this, external_name()); 183 184 // need to cast away volatile 185 it->push((Klass**)&_higher_dimension); 186 it->push((Klass**)&_lower_dimension); 187 } 188 189 #if INCLUDE_CDS 190 void ArrayKlass::remove_unshareable_info() { 191 Klass::remove_unshareable_info(); 192 if (_higher_dimension != nullptr) { 193 ArrayKlass *ak = higher_dimension(); 194 ak->remove_unshareable_info(); 195 } 196 } 197 198 void ArrayKlass::remove_java_mirror() { 199 Klass::remove_java_mirror(); 200 if (_higher_dimension != nullptr) { 201 ArrayKlass *ak = higher_dimension(); 202 ak->remove_java_mirror(); 203 } 204 } 205 206 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 207 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK); 208 // Klass recreates the component mirror also 209 210 if (_higher_dimension != nullptr) { 211 ArrayKlass *ak = higher_dimension(); 212 log_array_class_load(ak); 213 ak->restore_unshareable_info(loader_data, protection_domain, CHECK); 214 } 215 } 216 217 void ArrayKlass::cds_print_value_on(outputStream* st) const { 218 assert(is_klass(), "must be klass"); 219 st->print(" - array: %s", internal_name()); 220 if (_higher_dimension != nullptr) { 221 ArrayKlass* ak = higher_dimension(); 222 st->cr(); 223 ak->cds_print_value_on(st); 224 } 225 } 226 #endif // INCLUDE_CDS 227 228 void ArrayKlass::log_array_class_load(Klass* k) { 229 LogTarget(Debug, class, load, array) lt; 230 if (lt.is_enabled()) { 231 LogStream ls(lt); 232 ResourceMark rm; 233 ls.print("%s", k->name()->as_klass_external_name()); 234 if (MetaspaceShared::is_shared_dynamic((void*)k)) { 235 ls.print(" source: shared objects file (top)"); 236 } else if (MetaspaceShared::is_shared_static((void*)k)) { 237 ls.print(" source: shared objects file"); 238 } 239 ls.cr(); 240 } 241 } 242 243 // Printing 244 245 void ArrayKlass::print_on(outputStream* st) const { 246 assert(is_klass(), "must be klass"); 247 Klass::print_on(st); 248 } 249 250 void ArrayKlass::print_value_on(outputStream* st) const { 251 assert(is_klass(), "must be klass"); 252 for(int index = 0; index < dimension(); index++) { 253 st->print("[]"); 254 } 255 } 256 257 void ArrayKlass::oop_print_on(oop obj, outputStream* st) { 258 assert(obj->is_array(), "must be array"); 259 Klass::oop_print_on(obj, st); 260 st->print_cr(" - length: %d", arrayOop(obj)->length()); 261 } 262 263 264 // Verification 265 266 void ArrayKlass::verify_on(outputStream* st) { 267 Klass::verify_on(st); 268 } 269 270 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) { 271 guarantee(obj->is_array(), "must be array"); 272 arrayOop a = arrayOop(obj); 273 guarantee(a->length() >= 0, "array with negative length?"); 274 }