1 /* 2 * Copyright (c) 1997, 2016, 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 "gc/shared/gcLocker.hpp" 31 #include "jvmtifiles/jvmti.h" 32 #include "memory/resourceArea.hpp" 33 #include "memory/universe.inline.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 40 int ArrayKlass::static_size(int header_size) { 41 // size of an array klass object 42 assert(header_size <= InstanceKlass::header_size(), "bad header size"); 43 // If this assert fails, see comments in base_create_array_klass. 44 header_size = InstanceKlass::header_size(); 45 int vtable_len = Universe::base_vtable_size(); 46 int size = header_size + vtable_len; 47 return align_metadata_size(size); 48 } 49 50 51 Klass* ArrayKlass::java_super() const { 52 if (super() == NULL) return NULL; // bootstrap case 53 // Array klasses have primary supertypes which are not reported to Java. 54 // Example super chain: String[][] -> Object[][] -> Object[] -> Object 55 return SystemDictionary::Object_klass(); 56 } 57 58 59 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 60 ShouldNotReachHere(); 61 return NULL; 62 } 63 64 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined 65 Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 66 // There are no fields in an array klass but look to the super class (Object) 67 assert(super(), "super klass must be present"); 68 return super()->find_field(name, sig, fd); 69 } 70 71 Method* ArrayKlass::uncached_lookup_method(const Symbol* name, 72 const Symbol* signature, 73 OverpassLookupMode overpass_mode) const { 74 // There are no methods in an array klass but the super class (Object) has some 75 assert(super(), "super klass must be present"); 76 // Always ignore overpass methods in superclasses, although technically the 77 // super klass of an array, (j.l.Object) should not have 78 // any overpass methods present. 79 return super()->uncached_lookup_method(name, signature, Klass::skip_overpass); 80 } 81 82 ArrayKlass::ArrayKlass(Symbol* name) : 83 _dimension(1), 84 _higher_dimension(NULL), 85 _lower_dimension(NULL) { 86 // Arrays don't add any new methods, so their vtable is the same size as 87 // the vtable of klass Object. 88 set_vtable_length(Universe::base_vtable_size()); 89 set_name(name); 90 set_super(Universe::is_bootstrapping() ? (Klass*)NULL : SystemDictionary::Object_klass()); 91 set_layout_helper(Klass::_lh_neutral_value); 92 set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5) 93 TRACE_INIT_KLASS_ID(this); 94 } 95 96 97 // Initialization of vtables and mirror object is done separatly from base_create_array_klass, 98 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup. 99 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, KlassHandle super_klass, ModuleEntry* module_entry, TRAPS) { 100 ResourceMark rm(THREAD); 101 k->initialize_supers(super_klass(), CHECK); 102 k->vtable()->initialize_vtable(false, CHECK); 103 104 // During bootstrapping, before java.base is defined, the module_entry may not be present yet. 105 // These classes will be put on a fixup list and their module fields will be patched once 106 // java.base is defined. 107 assert((module_entry != NULL) || ((module_entry == NULL) && !ModuleEntryTable::javabase_defined()), 108 "module entry not available post " JAVA_BASE_NAME " definition"); 109 oop module = (module_entry != NULL) ? JNIHandles::resolve(module_entry->module()) : (oop)NULL; 110 java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(THREAD, module), Handle(NULL), CHECK); 111 } 112 113 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots) { 114 // interfaces = { cloneable_klass, serializable_klass }; 115 assert(num_extra_slots == 0, "sanity of primitive array type"); 116 // Must share this for correct bootstrapping! 117 set_secondary_supers(Universe::the_array_interfaces_array()); 118 return NULL; 119 } 120 121 bool ArrayKlass::compute_is_subtype_of(Klass* k) { 122 // An array is a subtype of Serializable, Clonable, and Object 123 return k == SystemDictionary::Object_klass() 124 || k == SystemDictionary::Cloneable_klass() 125 || k == SystemDictionary::Serializable_klass(); 126 } 127 128 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) { 129 if (length < 0) { 130 THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 131 } 132 if (length > arrayOopDesc::max_array_length(T_ARRAY)) { 133 report_java_out_of_memory("Requested array size exceeds VM limit"); 134 JvmtiExport::post_array_size_exhausted(); 135 THROW_OOP_0(Universe::out_of_memory_error_array_size()); 136 } 137 int size = objArrayOopDesc::object_size(length); 138 Klass* k = array_klass(n+dimension(), CHECK_0); 139 ArrayKlass* ak = ArrayKlass::cast(k); 140 objArrayOop o = 141 (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_0); 142 // initialization to NULL not necessary, area already cleared 143 return o; 144 } 145 146 void ArrayKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) { 147 Klass* k = this; 148 // Iterate over this array klass and all higher dimensions 149 while (k != NULL) { 150 f(k, CHECK); 151 k = ArrayKlass::cast(k)->higher_dimension(); 152 } 153 } 154 155 void ArrayKlass::array_klasses_do(void f(Klass* k)) { 156 Klass* k = this; 157 // Iterate over this array klass and all higher dimensions 158 while (k != NULL) { 159 f(k); 160 k = ArrayKlass::cast(k)->higher_dimension(); 161 } 162 } 163 164 // JVM support 165 166 jint ArrayKlass::compute_modifier_flags(TRAPS) const { 167 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 168 } 169 170 // JVMTI support 171 172 jint ArrayKlass::jvmti_class_status() const { 173 return JVMTI_CLASS_STATUS_ARRAY; 174 } 175 176 void ArrayKlass::remove_unshareable_info() { 177 Klass::remove_unshareable_info(); 178 } 179 180 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 181 assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader"); 182 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK); 183 // Klass recreates the component mirror also 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 }