1 /* 2 * Copyright (c) 1997, 2018, 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/systemDictionary.hpp" 28 #include "classfile/vmSymbols.hpp" 29 #include "gc/shared/collectedHeap.inline.hpp" 30 #include "jvmtifiles/jvmti.h" 31 #include "memory/metaspaceClosure.hpp" 32 #include "memory/resourceArea.hpp" 33 #include "memory/universe.hpp" 34 #include "oops/arrayKlass.hpp" 35 #include "oops/arrayOop.hpp" 36 #include "oops/instanceKlass.hpp" 37 #include "oops/objArrayOop.hpp" 38 #include "oops/oop.inline.hpp" 39 #include "runtime/handles.inline.hpp" 40 41 int ArrayKlass::static_size(int header_size) { 42 // size of an array klass object 43 assert(header_size <= InstanceKlass::header_size(), "bad header size"); 44 // If this assert fails, see comments in base_create_array_klass. 45 header_size = InstanceKlass::header_size(); 46 int vtable_len = Universe::base_vtable_size(); 47 int size = header_size + vtable_len; 48 return align_metadata_size(size); 49 } 50 51 52 Klass* ArrayKlass::java_super() const { 53 if (super() == NULL) return NULL; // bootstrap case 54 // Array klasses have primary supertypes which are not reported to Java. 55 // Example super chain: String[][] -> Object[][] -> Object[] -> Object 56 return SystemDictionary::Object_klass(); 57 } 58 59 60 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 61 ShouldNotReachHere(); 62 return NULL; 63 } 64 65 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined 66 Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 67 // There are no fields in an array klass but look to the super class (Object) 68 assert(super(), "super klass must be present"); 69 return super()->find_field(name, sig, fd); 70 } 71 72 Method* ArrayKlass::uncached_lookup_method(const Symbol* name, 73 const Symbol* signature, 74 OverpassLookupMode overpass_mode, 75 PrivateLookupMode private_mode) const { 76 // There are no methods in an array klass but the super class (Object) has some 77 assert(super(), "super klass must be present"); 78 // Always ignore overpass methods in superclasses, although technically the 79 // super klass of an array, (j.l.Object) should not have 80 // any overpass methods present. 81 return super()->uncached_lookup_method(name, signature, Klass::skip_overpass, private_mode); 82 } 83 84 ArrayKlass::ArrayKlass(Symbol* name) : 85 _dimension(1), 86 _higher_dimension(NULL), 87 _lower_dimension(NULL) { 88 // Arrays don't add any new methods, so their vtable is the same size as 89 // the vtable of klass Object. 90 set_vtable_length(Universe::base_vtable_size()); 91 set_name(name); 92 set_super(Universe::is_bootstrapping() ? (Klass*)NULL : SystemDictionary::Object_klass()); 93 set_layout_helper(Klass::_lh_neutral_value); 94 set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5) 95 TRACE_INIT_ID(this); 96 } 97 98 99 // Initialization of vtables and mirror object is done separatly from base_create_array_klass, 100 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup. 101 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module_entry, TRAPS) { 102 ResourceMark rm(THREAD); 103 k->initialize_supers(super_klass, NULL, CHECK); 104 k->vtable().initialize_vtable(false, CHECK); 105 106 // During bootstrapping, before java.base is defined, the module_entry may not be present yet. 107 // These classes will be put on a fixup list and their module fields will be patched once 108 // java.base is defined. 109 assert((module_entry != NULL) || ((module_entry == NULL) && !ModuleEntryTable::javabase_defined()), 110 "module entry not available post " JAVA_BASE_NAME " definition"); 111 oop module = (module_entry != NULL) ? module_entry->module() : (oop)NULL; 112 java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(THREAD, module), Handle(), CHECK); 113 } 114 115 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots, 116 Array<Klass*>* transitive_interfaces) { 117 // interfaces = { cloneable_klass, serializable_klass }; 118 assert(num_extra_slots == 0, "sanity of primitive array type"); 119 assert(transitive_interfaces == NULL, "sanity"); 120 // Must share this for correct bootstrapping! 121 set_secondary_supers(Universe::the_array_interfaces_array()); 122 return NULL; 123 } 124 125 bool ArrayKlass::compute_is_subtype_of(Klass* k) { 126 // An array is a subtype of Serializable, Clonable, and Object 127 return k == SystemDictionary::Object_klass() 128 || k == SystemDictionary::Cloneable_klass() 129 || k == SystemDictionary::Serializable_klass(); 130 } 131 132 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) { 133 if (length < 0) { 134 THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 135 } 136 if (length > arrayOopDesc::max_array_length(T_ARRAY)) { 137 report_java_out_of_memory("Requested array size exceeds VM limit"); 138 JvmtiExport::post_array_size_exhausted(); 139 THROW_OOP_0(Universe::out_of_memory_error_array_size()); 140 } 141 int size = objArrayOopDesc::object_size(length); 142 Klass* k = array_klass(n+dimension(), CHECK_0); 143 ArrayKlass* ak = ArrayKlass::cast(k); 144 objArrayOop o = 145 (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_0); 146 // initialization to NULL not necessary, area already cleared 147 return o; 148 } 149 150 void ArrayKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) { 151 Klass* k = this; 152 // Iterate over this array klass and all higher dimensions 153 while (k != NULL) { 154 f(k, CHECK); 155 k = ArrayKlass::cast(k)->higher_dimension(); 156 } 157 } 158 159 void ArrayKlass::array_klasses_do(void f(Klass* k)) { 160 Klass* k = this; 161 // Iterate over this array klass and all higher dimensions 162 while (k != NULL) { 163 f(k); 164 k = ArrayKlass::cast(k)->higher_dimension(); 165 } 166 } 167 168 // JVM support 169 170 jint ArrayKlass::compute_modifier_flags(TRAPS) const { 171 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 172 } 173 174 // JVMTI support 175 176 jint ArrayKlass::jvmti_class_status() const { 177 return JVMTI_CLASS_STATUS_ARRAY; 178 } 179 180 void ArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) { 181 Klass::metaspace_pointers_do(it); 182 183 ResourceMark rm; 184 log_trace(cds)("Iter(ArrayKlass): %p (%s)", this, external_name()); 185 186 // need to cast away volatile 187 it->push((Klass**)&_higher_dimension); 188 it->push((Klass**)&_lower_dimension); 189 } 190 191 void ArrayKlass::remove_unshareable_info() { 192 Klass::remove_unshareable_info(); 193 if (_higher_dimension != NULL) { 194 ArrayKlass *ak = ArrayKlass::cast(higher_dimension()); 195 ak->remove_unshareable_info(); 196 } 197 } 198 199 void ArrayKlass::remove_java_mirror() { 200 Klass::remove_java_mirror(); 201 if (_higher_dimension != NULL) { 202 ArrayKlass *ak = ArrayKlass::cast(higher_dimension()); 203 ak->remove_java_mirror(); 204 } 205 } 206 207 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 208 assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader"); 209 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK); 210 // Klass recreates the component mirror also 211 212 if (_higher_dimension != NULL) { 213 ArrayKlass *ak = ArrayKlass::cast(higher_dimension()); 214 ak->restore_unshareable_info(loader_data, protection_domain, CHECK); 215 } 216 } 217 218 // Printing 219 220 void ArrayKlass::print_on(outputStream* st) const { 221 assert(is_klass(), "must be klass"); 222 Klass::print_on(st); 223 } 224 225 void ArrayKlass::print_value_on(outputStream* st) const { 226 assert(is_klass(), "must be klass"); 227 for(int index = 0; index < dimension(); index++) { 228 st->print("[]"); 229 } 230 } 231 232 void ArrayKlass::oop_print_on(oop obj, outputStream* st) { 233 assert(obj->is_array(), "must be array"); 234 Klass::oop_print_on(obj, st); 235 st->print_cr(" - length: %d", arrayOop(obj)->length()); 236 } 237 238 239 // Verification 240 241 void ArrayKlass::verify_on(outputStream* st) { 242 Klass::verify_on(st); 243 } 244 245 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) { 246 guarantee(obj->is_array(), "must be array"); 247 arrayOop a = arrayOop(obj); 248 guarantee(a->length() >= 0, "array with negative length?"); 249 }