1 /* 2 * Copyright (c) 1997, 2020, 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/systemDictionary.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/objArrayOop.hpp" 39 #include "oops/oop.inline.hpp" 40 #include "runtime/handles.inline.hpp" 41 42 int ArrayKlass::static_size(int header_size) { 43 // size of an array klass object 44 assert(header_size <= InstanceKlass::header_size(), "bad header size"); 45 // If this assert fails, see comments in base_create_array_klass. 46 header_size = InstanceKlass::header_size(); 47 int vtable_len = Universe::base_vtable_size(); 48 int size = header_size + vtable_len; 49 return align_metadata_size(size); 50 } 51 52 53 InstanceKlass* ArrayKlass::java_super() const { 54 if (super() == NULL) return NULL; // bootstrap case 55 // Array klasses have primary supertypes which are not reported to Java. 56 // Example super chain: String[][] -> Object[][] -> Object[] -> Object 57 return SystemDictionary::Object_klass(); 58 } 59 60 61 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 62 ShouldNotReachHere(); 63 return NULL; 64 } 65 66 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined 67 Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 68 // There are no fields in an array klass but look to the super class (Object) 69 assert(super(), "super klass must be present"); 70 return super()->find_field(name, sig, fd); 71 } 72 73 Method* ArrayKlass::uncached_lookup_method(const Symbol* name, 74 const Symbol* signature, 75 OverpassLookupMode overpass_mode, 76 PrivateLookupMode private_mode) const { 77 // There are no methods in an array klass but the super class (Object) has some 78 assert(super(), "super klass must be present"); 79 // Always ignore overpass methods in superclasses, although technically the 80 // super klass of an array, (j.l.Object) should not have 81 // any overpass methods present. 82 return super()->uncached_lookup_method(name, signature, Klass::skip_overpass, private_mode); 83 } 84 85 ArrayKlass::ArrayKlass(Symbol* name, KlassID id) : 86 Klass(id), 87 _dimension(1), 88 _higher_dimension(NULL), 89 _lower_dimension(NULL) { 90 // Arrays don't add any new methods, so their vtable is the same size as 91 // the vtable of klass Object. 92 set_vtable_length(Universe::base_vtable_size()); 93 set_name(name); 94 set_super(Universe::is_bootstrapping() ? NULL : SystemDictionary::Object_klass()); 95 set_layout_helper(Klass::_lh_neutral_value); 96 set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5) 97 JFR_ONLY(INIT_ID(this);) 98 } 99 100 101 // Initialization of vtables and mirror object is done separatly from base_create_array_klass, 102 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup. 103 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module_entry, TRAPS) { 104 k->initialize_supers(super_klass, NULL, CHECK); 105 k->vtable().initialize_vtable(false, CHECK); 106 107 // During bootstrapping, before java.base is defined, the module_entry may not be present yet. 108 // These classes will be put on a fixup list and their module fields will be patched once 109 // java.base is defined. 110 assert((module_entry != NULL) || ((module_entry == NULL) && !ModuleEntryTable::javabase_defined()), 111 "module entry not available post " JAVA_BASE_NAME " definition"); 112 oop module = (module_entry != NULL) ? module_entry->module() : (oop)NULL; 113 java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(THREAD, module), Handle(), CHECK); 114 } 115 116 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots, 117 Array<InstanceKlass*>* transitive_interfaces) { 118 // interfaces = { cloneable_klass, serializable_klass }; 119 assert(num_extra_slots == 0, "sanity of primitive array type"); 120 assert(transitive_interfaces == NULL, "sanity"); 121 // Must share this for correct bootstrapping! 122 set_secondary_supers(Universe::the_array_interfaces_array()); 123 return NULL; 124 } 125 126 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) { 127 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_ARRAY), CHECK_NULL); 128 int size = objArrayOopDesc::object_size(length); 129 Klass* k = array_klass(n+dimension(), CHECK_NULL); 130 ArrayKlass* ak = ArrayKlass::cast(k); 131 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length, 132 /* do_zero */ true, CHECK_NULL); 133 // initialization to NULL not necessary, area already cleared 134 return o; 135 } 136 137 void ArrayKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) { 138 Klass* k = this; 139 // Iterate over this array klass and all higher dimensions 140 while (k != NULL) { 141 f(k, CHECK); 142 k = ArrayKlass::cast(k)->higher_dimension(); 143 } 144 } 145 146 void ArrayKlass::array_klasses_do(void f(Klass* k)) { 147 Klass* k = this; 148 // Iterate over this array klass and all higher dimensions 149 while (k != NULL) { 150 f(k); 151 k = ArrayKlass::cast(k)->higher_dimension(); 152 } 153 } 154 155 // JVM support 156 157 jint ArrayKlass::compute_modifier_flags(TRAPS) const { 158 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 159 } 160 161 // JVMTI support 162 163 jint ArrayKlass::jvmti_class_status() const { 164 return JVMTI_CLASS_STATUS_ARRAY; 165 } 166 167 void ArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) { 168 Klass::metaspace_pointers_do(it); 169 170 ResourceMark rm; 171 log_trace(cds)("Iter(ArrayKlass): %p (%s)", this, external_name()); 172 173 // need to cast away volatile 174 it->push((Klass**)&_higher_dimension); 175 it->push((Klass**)&_lower_dimension); 176 } 177 178 void ArrayKlass::remove_unshareable_info() { 179 Klass::remove_unshareable_info(); 180 if (_higher_dimension != NULL) { 181 ArrayKlass *ak = ArrayKlass::cast(higher_dimension()); 182 ak->remove_unshareable_info(); 183 } 184 } 185 186 void ArrayKlass::remove_java_mirror() { 187 Klass::remove_java_mirror(); 188 if (_higher_dimension != NULL) { 189 ArrayKlass *ak = ArrayKlass::cast(higher_dimension()); 190 ak->remove_java_mirror(); 191 } 192 } 193 194 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 195 assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader"); 196 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK); 197 // Klass recreates the component mirror also 198 199 if (_higher_dimension != NULL) { 200 ArrayKlass *ak = ArrayKlass::cast(higher_dimension()); 201 ak->restore_unshareable_info(loader_data, protection_domain, CHECK); 202 } 203 } 204 205 // Printing 206 207 void ArrayKlass::print_on(outputStream* st) const { 208 assert(is_klass(), "must be klass"); 209 Klass::print_on(st); 210 } 211 212 void ArrayKlass::print_value_on(outputStream* st) const { 213 assert(is_klass(), "must be klass"); 214 for(int index = 0; index < dimension(); index++) { 215 st->print("[]"); 216 } 217 } 218 219 void ArrayKlass::oop_print_on(oop obj, outputStream* st) { 220 assert(obj->is_array(), "must be array"); 221 Klass::oop_print_on(obj, st); 222 st->print_cr(" - length: %d", arrayOop(obj)->length()); 223 } 224 225 226 // Verification 227 228 void ArrayKlass::verify_on(outputStream* st) { 229 Klass::verify_on(st); 230 } 231 232 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) { 233 guarantee(obj->is_array(), "must be array"); 234 arrayOop a = arrayOop(obj); 235 guarantee(a->length() >= 0, "array with negative length?"); 236 }