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, TRAPS) {
100 ResourceMark rm(THREAD);
101 k->initialize_supers(super_klass(), CHECK);
102 k->vtable()->initialize_vtable(false, CHECK);
103 java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(NULL), CHECK);
104 }
105
106 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots) {
107 // interfaces = { cloneable_klass, serializable_klass };
108 assert(num_extra_slots == 0, "sanity of primitive array type");
109 // Must share this for correct bootstrapping!
110 set_secondary_supers(Universe::the_array_interfaces_array());
111 return NULL;
112 }
113
114 bool ArrayKlass::compute_is_subtype_of(Klass* k) {
115 // An array is a subtype of Serializable, Clonable, and Object
116 return k == SystemDictionary::Object_klass()
117 || k == SystemDictionary::Cloneable_klass()
118 || k == SystemDictionary::Serializable_klass();
119 }
120
121 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) {
122 if (length < 0) {
123 THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
124 }
125 if (length > arrayOopDesc::max_array_length(T_ARRAY)) {
126 report_java_out_of_memory("Requested array size exceeds VM limit");
127 JvmtiExport::post_array_size_exhausted();
128 THROW_OOP_0(Universe::out_of_memory_error_array_size());
129 }
130 int size = objArrayOopDesc::object_size(length);
131 Klass* k = array_klass(n+dimension(), CHECK_0);
132 ArrayKlass* ak = ArrayKlass::cast(k);
133 objArrayOop o =
134 (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_0);
135 // initialization to NULL not necessary, area already cleared
136 return o;
137 }
138
139 void ArrayKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
140 Klass* k = this;
141 // Iterate over this array klass and all higher dimensions
142 while (k != NULL) {
143 f(k, CHECK);
144 k = ArrayKlass::cast(k)->higher_dimension();
145 }
146 }
147
148 void ArrayKlass::array_klasses_do(void f(Klass* k)) {
149 Klass* k = this;
150 // Iterate over this array klass and all higher dimensions
151 while (k != NULL) {
152 f(k);
153 k = ArrayKlass::cast(k)->higher_dimension();
154 }
155 }
156
157 // JVM support
158
159 jint ArrayKlass::compute_modifier_flags(TRAPS) const {
160 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
161 }
162
163 // JVMTI support
164
165 jint ArrayKlass::jvmti_class_status() const {
166 return JVMTI_CLASS_STATUS_ARRAY;
167 }
168
169 void ArrayKlass::remove_unshareable_info() {
170 Klass::remove_unshareable_info();
171 }
172
173 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
174 assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader");
175 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
176 // Klass recreates the component mirror also
177 }
178
179 // Printing
180
181 void ArrayKlass::print_on(outputStream* st) const {
182 assert(is_klass(), "must be klass");
183 Klass::print_on(st);
184 }
185
186 void ArrayKlass::print_value_on(outputStream* st) const {
187 assert(is_klass(), "must be klass");
188 for(int index = 0; index < dimension(); index++) {
189 st->print("[]");
190 }
191 }
192
193 void ArrayKlass::oop_print_on(oop obj, outputStream* st) {
194 assert(obj->is_array(), "must be array");
195 Klass::oop_print_on(obj, st);
196 st->print_cr(" - length: %d", arrayOop(obj)->length());
197 }
198
199
200 // Verification
201
202 void ArrayKlass::verify_on(outputStream* st) {
203 Klass::verify_on(st);
204 }
205
206 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) {
207 guarantee(obj->is_array(), "must be array");
208 arrayOop a = arrayOop(obj);
209 guarantee(a->length() >= 0, "array with negative length?");
210 }