1 /* 2 * Copyright (c) 1997, 2015, 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/universe.inline.hpp" 33 #include "oops/arrayKlass.hpp" 34 #include "oops/arrayOop.hpp" 35 #include "oops/instanceKlass.hpp" 36 #include "oops/objArrayOop.hpp" 37 #include "oops/oop.inline.hpp" 38 39 int ArrayKlass::static_size(int header_size) { 40 // size of an array klass object 41 assert(header_size <= InstanceKlass::header_size(), "bad header size"); 42 // If this assert fails, see comments in base_create_array_klass. 43 header_size = InstanceKlass::header_size(); 44 int vtable_len = Universe::base_vtable_size(); 45 int size = header_size + vtable_len; 46 return align_object_size(size); 47 } 48 49 50 Klass* ArrayKlass::java_super() const { 51 if (super() == NULL) return NULL; // bootstrap case 52 // Array klasses have primary supertypes which are not reported to Java. 53 // Example super chain: String[][] -> Object[][] -> Object[] -> Object 54 return SystemDictionary::Object_klass(); 55 } 56 57 58 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 59 ShouldNotReachHere(); 60 return NULL; 61 } 62 63 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined 64 Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const { 65 // There are no fields in an array klass but look to the super class (Object) 66 assert(super(), "super klass must be present"); 67 return super()->find_field(name, sig, fd); 68 } 69 70 Method* ArrayKlass::uncached_lookup_method(const Symbol* name, 71 const Symbol* signature, 72 OverpassLookupMode overpass_mode) const { 73 // There are no methods in an array klass but the super class (Object) has some 74 assert(super(), "super klass must be present"); 75 // Always ignore overpass methods in superclasses, although technically the 76 // super klass of an array, (j.l.Object) should not have 77 // any overpass methods present. 78 return super()->uncached_lookup_method(name, signature, Klass::skip_overpass); 79 } 80 81 ArrayKlass::ArrayKlass(Symbol* name) : 82 _dimension(1), 83 _higher_dimension(NULL), 84 _lower_dimension(NULL), 85 // Arrays don't add any new methods, so their vtable is the same size as 86 // the vtable of klass Object. 87 _vtable_len(Universe::base_vtable_size()) { 88 set_name(name); 89 set_super(Universe::is_bootstrapping() ? (Klass*)NULL : SystemDictionary::Object_klass()); 90 set_layout_helper(Klass::_lh_neutral_value); 91 set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5) 92 TRACE_INIT_ID(this); 93 } 94 95 96 // Initialization of vtables and mirror object is done separatly from base_create_array_klass, 97 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup. 98 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, KlassHandle super_klass, TRAPS) { 99 ResourceMark rm(THREAD); 100 k->initialize_supers(super_klass(), CHECK); 101 k->vtable()->initialize_vtable(false, CHECK); 102 java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(NULL), CHECK); 103 } 104 105 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots) { 106 // interfaces = { cloneable_klass, serializable_klass }; 107 assert(num_extra_slots == 0, "sanity of primitive array type"); 108 // Must share this for correct bootstrapping! 109 set_secondary_supers(Universe::the_array_interfaces_array()); 110 return NULL; 111 } 112 113 bool ArrayKlass::compute_is_subtype_of(Klass* k) { 114 // An array is a subtype of Serializable, Clonable, and Object 115 return k == SystemDictionary::Object_klass() 116 || k == SystemDictionary::Cloneable_klass() 117 || k == SystemDictionary::Serializable_klass(); 118 } 119 120 121 inline intptr_t* ArrayKlass::start_of_vtable() const { 122 // all vtables start at the same place, that's why we use InstanceKlass::header_size here 123 return ((intptr_t*)this) + InstanceKlass::header_size(); 124 } 125 126 127 klassVtable* ArrayKlass::vtable() const { 128 KlassHandle kh(Thread::current(), this); 129 return new klassVtable(kh, start_of_vtable(), vtable_length() / vtableEntry::size()); 130 } 131 132 133 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) { 134 if (length < 0) { 135 THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 136 } 137 if (length > arrayOopDesc::max_array_length(T_ARRAY)) { 138 report_java_out_of_memory("Requested array size exceeds VM limit"); 139 JvmtiExport::post_array_size_exhausted(); 140 THROW_OOP_0(Universe::out_of_memory_error_array_size()); 141 } 142 int size = objArrayOopDesc::object_size(length); 143 Klass* k = array_klass(n+dimension(), CHECK_0); 144 ArrayKlass* ak = ArrayKlass::cast(k); 145 objArrayOop o = 146 (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_0); 147 // initialization to NULL not necessary, area already cleared 148 return o; 149 } 150 151 void ArrayKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) { 152 Klass* k = this; 153 // Iterate over this array klass and all higher dimensions 154 while (k != NULL) { 155 f(k, CHECK); 156 k = ArrayKlass::cast(k)->higher_dimension(); 157 } 158 } 159 160 void ArrayKlass::array_klasses_do(void f(Klass* k)) { 161 Klass* k = this; 162 // Iterate over this array klass and all higher dimensions 163 while (k != NULL) { 164 f(k); 165 k = ArrayKlass::cast(k)->higher_dimension(); 166 } 167 } 168 169 // JVM support 170 171 jint ArrayKlass::compute_modifier_flags(TRAPS) const { 172 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 173 } 174 175 // JVMTI support 176 177 jint ArrayKlass::jvmti_class_status() const { 178 return JVMTI_CLASS_STATUS_ARRAY; 179 } 180 181 void ArrayKlass::remove_unshareable_info() { 182 Klass::remove_unshareable_info(); 183 } 184 185 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 186 assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader"); 187 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK); 188 // Klass recreates the component mirror also 189 } 190 191 // Printing 192 193 void ArrayKlass::print_on(outputStream* st) const { 194 assert(is_klass(), "must be klass"); 195 Klass::print_on(st); 196 } 197 198 void ArrayKlass::print_value_on(outputStream* st) const { 199 assert(is_klass(), "must be klass"); 200 for(int index = 0; index < dimension(); index++) { 201 st->print("[]"); 202 } 203 } 204 205 void ArrayKlass::oop_print_on(oop obj, outputStream* st) { 206 assert(obj->is_array(), "must be array"); 207 Klass::oop_print_on(obj, st); 208 st->print_cr(" - length: %d", arrayOop(obj)->length()); 209 } 210 211 212 // Verification 213 214 void ArrayKlass::verify_on(outputStream* st) { 215 Klass::verify_on(st); 216 } 217 218 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) { 219 guarantee(obj->is_array(), "must be array"); 220 arrayOop a = arrayOop(obj); 221 guarantee(a->length() >= 0, "array with negative length?"); 222 }