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