1 /* 2 * Copyright (c) 1997, 2009, 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 "incls/_precompiled.incl" 26 # include "incls/_arrayKlass.cpp.incl" 27 28 int arrayKlass::object_size(int header_size) const { 29 // size of an array klass object 30 assert(header_size <= instanceKlass::header_size(), "bad header size"); 31 // If this assert fails, see comments in base_create_array_klass. 32 header_size = instanceKlass::header_size(); 33 #ifdef _LP64 34 int size = header_size + align_object_offset(vtable_length()); 35 #else 36 int size = header_size + vtable_length(); 37 #endif 38 return align_object_size(size); 39 } 40 41 42 klassOop arrayKlass::java_super() const { 43 if (super() == NULL) return NULL; // bootstrap case 44 // Array klasses have primary supertypes which are not reported to Java. 45 // Example super chain: String[][] -> Object[][] -> Object[] -> Object 46 return SystemDictionary::Object_klass(); 47 } 48 49 50 oop arrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 51 ShouldNotReachHere(); 52 return NULL; 53 } 54 55 methodOop arrayKlass::uncached_lookup_method(symbolOop name, symbolOop signature) const { 56 // There are no methods in an array klass but the super class (Object) has some 57 assert(super(), "super klass must be present"); 58 return Klass::cast(super())->uncached_lookup_method(name, signature); 59 } 60 61 62 arrayKlassHandle arrayKlass::base_create_array_klass( 63 const Klass_vtbl& cplusplus_vtbl, int header_size, KlassHandle klass, TRAPS) { 64 // Allocation 65 // Note: because the Java vtable must start at the same offset in all klasses, 66 // we must insert filler fields into arrayKlass to make it the same size as instanceKlass. 67 // If this assert fails, add filler to instanceKlass to make it bigger. 68 assert(header_size <= instanceKlass::header_size(), 69 "array klasses must be same size as instanceKlass"); 70 header_size = instanceKlass::header_size(); 71 // Arrays don't add any new methods, so their vtable is the same size as 72 // the vtable of klass Object. 73 int vtable_size = Universe::base_vtable_size(); 74 arrayKlassHandle k; 75 KlassHandle base_klass = Klass::base_create_klass(klass, 76 header_size + vtable_size, 77 cplusplus_vtbl, CHECK_(k)); 78 79 // No safepoint should be possible until the handle's 80 // target below becomes parsable 81 No_Safepoint_Verifier no_safepoint; 82 k = arrayKlassHandle(THREAD, base_klass()); 83 84 assert(!k()->is_parsable(), "not expecting parsability yet."); 85 k->set_super(Universe::is_bootstrapping() ? (klassOop)NULL : SystemDictionary::Object_klass()); 86 k->set_layout_helper(Klass::_lh_neutral_value); 87 k->set_dimension(1); 88 k->set_higher_dimension(NULL); 89 k->set_lower_dimension(NULL); 90 k->set_component_mirror(NULL); 91 k->set_vtable_length(vtable_size); 92 k->set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5) 93 94 assert(k()->is_parsable(), "should be parsable here."); 95 // Make sure size calculation is right 96 assert(k()->size() == align_object_size(header_size + vtable_size), "wrong size for object"); 97 98 return k; 99 } 100 101 102 // Initialization of vtables and mirror object is done separatly from base_create_array_klass, 103 // since a GC can happen. At this point all instance variables of the arrayKlass must be setup. 104 void arrayKlass::complete_create_array_klass(arrayKlassHandle k, KlassHandle super_klass, TRAPS) { 105 ResourceMark rm(THREAD); 106 k->initialize_supers(super_klass(), CHECK); 107 k->vtable()->initialize_vtable(false, CHECK); 108 java_lang_Class::create_mirror(k, CHECK); 109 } 110 111 objArrayOop arrayKlass::compute_secondary_supers(int num_extra_slots, TRAPS) { 112 // interfaces = { cloneable_klass, serializable_klass }; 113 assert(num_extra_slots == 0, "sanity of primitive array type"); 114 // Must share this for correct bootstrapping! 115 return Universe::the_array_interfaces_array(); 116 } 117 118 bool arrayKlass::compute_is_subtype_of(klassOop k) { 119 // An array is a subtype of Serializable, Clonable, and Object 120 return k == SystemDictionary::Object_klass() 121 || k == SystemDictionary::Cloneable_klass() 122 || k == SystemDictionary::Serializable_klass(); 123 } 124 125 126 inline intptr_t* arrayKlass::start_of_vtable() const { 127 // all vtables start at the same place, that's why we use instanceKlass::header_size here 128 return ((intptr_t*)as_klassOop()) + instanceKlass::header_size(); 129 } 130 131 132 klassVtable* arrayKlass::vtable() const { 133 KlassHandle kh(Thread::current(), as_klassOop()); 134 return new klassVtable(kh, start_of_vtable(), vtable_length() / vtableEntry::size()); 135 } 136 137 138 objArrayOop arrayKlass::allocate_arrayArray(int n, int length, TRAPS) { 139 if (length < 0) { 140 THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 141 } 142 if (length > arrayOopDesc::max_array_length(T_ARRAY)) { 143 report_java_out_of_memory("Requested array size exceeds VM limit"); 144 THROW_OOP_0(Universe::out_of_memory_error_array_size()); 145 } 146 int size = objArrayOopDesc::object_size(length); 147 klassOop k = array_klass(n+dimension(), CHECK_0); 148 arrayKlassHandle ak (THREAD, k); 149 objArrayOop o = 150 (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_0); 151 // initialization to NULL not necessary, area already cleared 152 return o; 153 } 154 155 156 void arrayKlass::array_klasses_do(void f(klassOop k)) { 157 klassOop k = as_klassOop(); 158 // Iterate over this array klass and all higher dimensions 159 while (k != NULL) { 160 f(k); 161 k = arrayKlass::cast(k)->higher_dimension(); 162 } 163 } 164 165 166 void arrayKlass::with_array_klasses_do(void f(klassOop k)) { 167 array_klasses_do(f); 168 } 169 170 // JVM support 171 172 jint arrayKlass::compute_modifier_flags(TRAPS) const { 173 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 174 } 175 176 // JVMTI support 177 178 jint arrayKlass::jvmti_class_status() const { 179 return JVMTI_CLASS_STATUS_ARRAY; 180 } 181 182 // Printing 183 184 void arrayKlass::oop_print_on(oop obj, outputStream* st) { 185 assert(obj->is_array(), "must be array"); 186 Klass::oop_print_on(obj, st); 187 st->print_cr(" - length: %d", arrayOop(obj)->length()); 188 } 189 190 // Verification 191 192 void arrayKlass::oop_verify_on(oop obj, outputStream* st) { 193 guarantee(obj->is_array(), "must be array"); 194 arrayOop a = arrayOop(obj); 195 guarantee(a->length() >= 0, "array with negative length?"); 196 }