1 /* 2 * Copyright (c) 1997, 2014, 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_interface/collectedHeap.inline.hpp" 30 #include "jvmtifiles/jvmti.h" 31 #include "memory/gcLocker.hpp" 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 #ifdef _LP64 46 int size = header_size + align_object_offset(vtable_len); 47 #else 48 int size = header_size + vtable_len; 49 #endif 50 return align_object_size(size); 51 } 52 53 54 Klass* ArrayKlass::java_super() const { 55 if (super() == NULL) return NULL; // bootstrap case 56 // Array klasses have primary supertypes which are not reported to Java. 57 // Example super chain: String[][] -> Object[][] -> Object[] -> Object 58 return SystemDictionary::Object_klass(); 59 } 60 61 62 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 63 ShouldNotReachHere(); 64 return NULL; 65 } 66 67 Method* ArrayKlass::uncached_lookup_method(Symbol* name, Symbol* signature, MethodLookupMode mode) const { 68 // There are no methods in an array klass but the super class (Object) has some 69 assert(super(), "super klass must be present"); 70 return super()->uncached_lookup_method(name, signature, mode); 71 } 72 73 ArrayKlass::ArrayKlass(Symbol* name) { 74 set_name(name); 75 76 set_super(Universe::is_bootstrapping() ? (Klass*)NULL : SystemDictionary::Object_klass()); 77 set_layout_helper(Klass::_lh_neutral_value); 78 set_dimension(1); 79 set_higher_dimension(NULL); 80 set_lower_dimension(NULL); 81 // Arrays don't add any new methods, so their vtable is the same size as 82 // the vtable of klass Object. 83 int vtable_size = Universe::base_vtable_size(); 84 set_vtable_length(vtable_size); 85 set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5) 86 } 87 88 89 // Initialization of vtables and mirror object is done separatly from base_create_array_klass, 90 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup. 91 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, KlassHandle super_klass, TRAPS) { 92 ResourceMark rm(THREAD); 93 k->initialize_supers(super_klass(), CHECK); 94 k->vtable()->initialize_vtable(false, CHECK); 95 java_lang_Class::create_mirror(k, Handle(NULL), Handle(NULL), CHECK); 96 } 97 98 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots) { 99 // interfaces = { cloneable_klass, serializable_klass }; 100 assert(num_extra_slots == 0, "sanity of primitive array type"); 101 // Must share this for correct bootstrapping! 102 set_secondary_supers(Universe::the_array_interfaces_array()); 103 return NULL; 104 } 105 106 bool ArrayKlass::compute_is_subtype_of(Klass* k) { 107 // An array is a subtype of Serializable, Clonable, and Object 108 return k == SystemDictionary::Object_klass() 109 || k == SystemDictionary::Cloneable_klass() 110 || k == SystemDictionary::Serializable_klass(); 111 } 112 113 114 inline intptr_t* ArrayKlass::start_of_vtable() const { 115 // all vtables start at the same place, that's why we use InstanceKlass::header_size here 116 return ((intptr_t*)this) + InstanceKlass::header_size(); 117 } 118 119 120 klassVtable* ArrayKlass::vtable() const { 121 KlassHandle kh(Thread::current(), this); 122 return new klassVtable(kh, start_of_vtable(), vtable_length() / vtableEntry::size()); 123 } 124 125 126 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) { 127 if (length < 0) { 128 THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 129 } 130 if (length > arrayOopDesc::max_array_length(T_ARRAY)) { 131 report_java_out_of_memory("Requested array size exceeds VM limit"); 132 JvmtiExport::post_array_size_exhausted(); 133 THROW_OOP_0(Universe::out_of_memory_error_array_size()); 134 } 135 int size = objArrayOopDesc::object_size(length); 136 Klass* k = array_klass(n+dimension(), CHECK_0); 137 ArrayKlass* ak = ArrayKlass::cast(k); 138 objArrayOop o = 139 (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_0); 140 // initialization to NULL not necessary, area already cleared 141 return o; 142 } 143 144 void ArrayKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) { 145 Klass* k = this; 146 // Iterate over this array klass and all higher dimensions 147 while (k != NULL) { 148 f(k, CHECK); 149 k = ArrayKlass::cast(k)->higher_dimension(); 150 } 151 } 152 153 void ArrayKlass::array_klasses_do(void f(Klass* k)) { 154 Klass* k = this; 155 // Iterate over this array klass and all higher dimensions 156 while (k != NULL) { 157 f(k); 158 k = ArrayKlass::cast(k)->higher_dimension(); 159 } 160 } 161 162 // JVM support 163 164 jint ArrayKlass::compute_modifier_flags(TRAPS) const { 165 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 166 } 167 168 // JVMTI support 169 170 jint ArrayKlass::jvmti_class_status() const { 171 return JVMTI_CLASS_STATUS_ARRAY; 172 } 173 174 void ArrayKlass::remove_unshareable_info() { 175 Klass::remove_unshareable_info(); 176 } 177 178 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) { 179 assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader"); 180 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK); 181 // Klass recreates the component mirror also 182 } 183 184 // Printing 185 186 void ArrayKlass::print_on(outputStream* st) const { 187 assert(is_klass(), "must be klass"); 188 Klass::print_on(st); 189 } 190 191 void ArrayKlass::print_value_on(outputStream* st) const { 192 assert(is_klass(), "must be klass"); 193 for(int index = 0; index < dimension(); index++) { 194 st->print("[]"); 195 } 196 } 197 198 void ArrayKlass::oop_print_on(oop obj, outputStream* st) { 199 assert(obj->is_array(), "must be array"); 200 Klass::oop_print_on(obj, st); 201 st->print_cr(" - length: %d", arrayOop(obj)->length()); 202 } 203 204 205 // Verification 206 207 void ArrayKlass::verify_on(outputStream* st) { 208 Klass::verify_on(st); 209 } 210 211 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) { 212 guarantee(obj->is_array(), "must be array"); 213 arrayOop a = arrayOop(obj); 214 guarantee(a->length() >= 0, "array with negative length?"); 215 }