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 }