1 /*
2 * Copyright (c) 1997, 2018, 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 "jvmtifiles/jvmti.h"
31 #include "memory/metaspaceClosure.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "memory/universe.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 #include "runtime/handles.inline.hpp"
40
41 int ArrayKlass::static_size(int header_size) {
42 // size of an array klass object
43 assert(header_size <= InstanceKlass::header_size(), "bad header size");
44 // If this assert fails, see comments in base_create_array_klass.
45 header_size = InstanceKlass::header_size();
46 int vtable_len = Universe::base_vtable_size();
47 int size = header_size + vtable_len;
48 return align_metadata_size(size);
49 }
50
51
52 InstanceKlass* ArrayKlass::java_super() const {
53 if (super() == NULL) return NULL; // bootstrap case
54 // Array klasses have primary supertypes which are not reported to Java.
55 // Example super chain: String[][] -> Object[][] -> Object[] -> Object
56 return SystemDictionary::Object_klass();
57 }
58
59
60 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
61 ShouldNotReachHere();
62 return NULL;
63 }
64
65 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
66 Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
67 // There are no fields in an array klass but look to the super class (Object)
68 assert(super(), "super klass must be present");
69 return super()->find_field(name, sig, fd);
70 }
71
72 Method* ArrayKlass::uncached_lookup_method(const Symbol* name,
73 const Symbol* signature,
74 OverpassLookupMode overpass_mode,
75 PrivateLookupMode private_mode) const {
76 // There are no methods in an array klass but the super class (Object) has some
77 assert(super(), "super klass must be present");
78 // Always ignore overpass methods in superclasses, although technically the
79 // super klass of an array, (j.l.Object) should not have
80 // any overpass methods present.
81 return super()->uncached_lookup_method(name, signature, Klass::skip_overpass, private_mode);
82 }
83
84 ArrayKlass::ArrayKlass(Symbol* name, KlassID id) :
85 Klass(id),
86 _dimension(1),
87 _higher_dimension(NULL),
88 _lower_dimension(NULL) {
89 // Arrays don't add any new methods, so their vtable is the same size as
90 // the vtable of klass Object.
91 set_vtable_length(Universe::base_vtable_size());
92 set_name(name);
93 set_super(Universe::is_bootstrapping() ? NULL : SystemDictionary::Object_klass());
94 set_layout_helper(Klass::_lh_neutral_value);
95 set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5)
96 JFR_ONLY(INIT_ID(this);)
97 }
98
99
100 // Initialization of vtables and mirror object is done separatly from base_create_array_klass,
101 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup.
102 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module_entry, TRAPS) {
103 k->initialize_supers(super_klass, NULL, CHECK);
104 k->vtable().initialize_vtable(false, CHECK);
105
106 // During bootstrapping, before java.base is defined, the module_entry may not be present yet.
107 // These classes will be put on a fixup list and their module fields will be patched once
108 // java.base is defined.
109 assert((module_entry != NULL) || ((module_entry == NULL) && !ModuleEntryTable::javabase_defined()),
110 "module entry not available post " JAVA_BASE_NAME " definition");
111 oop module = (module_entry != NULL) ? module_entry->module() : (oop)NULL;
112 java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(THREAD, module), Handle(), CHECK);
113 }
114
115 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots,
116 Array<InstanceKlass*>* transitive_interfaces) {
117 // interfaces = { cloneable_klass, serializable_klass };
118 assert(num_extra_slots == 0, "sanity of primitive array type");
119 assert(transitive_interfaces == NULL, "sanity");
120 // Must share this for correct bootstrapping!
121 set_secondary_supers(Universe::the_array_interfaces_array());
122 return NULL;
123 }
124
125 bool ArrayKlass::compute_is_subtype_of(Klass* k) {
126 // An array is a subtype of Serializable, Clonable, and Object
127 return k == SystemDictionary::Object_klass()
128 || k == SystemDictionary::Cloneable_klass()
129 || k == SystemDictionary::Serializable_klass();
130 }
131
132 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) {
133 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_ARRAY), CHECK_0);
134 int size = objArrayOopDesc::object_size(length);
135 Klass* k = array_klass(n+dimension(), CHECK_0);
136 ArrayKlass* ak = ArrayKlass::cast(k);
137 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
138 /* do_zero */ true, CHECK_0);
139 // initialization to NULL not necessary, area already cleared
140 return o;
141 }
142
143 void ArrayKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
144 Klass* k = this;
145 // Iterate over this array klass and all higher dimensions
146 while (k != NULL) {
147 f(k, CHECK);
148 k = ArrayKlass::cast(k)->higher_dimension();
149 }
150 }
151
152 void ArrayKlass::array_klasses_do(void f(Klass* k)) {
153 Klass* k = this;
154 // Iterate over this array klass and all higher dimensions
155 while (k != NULL) {
156 f(k);
157 k = ArrayKlass::cast(k)->higher_dimension();
158 }
159 }
160
161 // JVM support
162
163 jint ArrayKlass::compute_modifier_flags(TRAPS) const {
164 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
165 }
166
167 // JVMTI support
168
169 jint ArrayKlass::jvmti_class_status() const {
170 return JVMTI_CLASS_STATUS_ARRAY;
171 }
172
173 void ArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
174 Klass::metaspace_pointers_do(it);
175
176 ResourceMark rm;
177 log_trace(cds)("Iter(ArrayKlass): %p (%s)", this, external_name());
178
179 // need to cast away volatile
180 it->push((Klass**)&_higher_dimension);
181 it->push((Klass**)&_lower_dimension);
182 }
183
184 void ArrayKlass::remove_unshareable_info() {
185 Klass::remove_unshareable_info();
186 if (_higher_dimension != NULL) {
187 ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
188 ak->remove_unshareable_info();
189 }
190 }
191
192 void ArrayKlass::remove_java_mirror() {
193 Klass::remove_java_mirror();
194 if (_higher_dimension != NULL) {
195 ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
196 ak->remove_java_mirror();
197 }
198 }
199
200 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
201 assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader");
202 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
203 // Klass recreates the component mirror also
204
205 if (_higher_dimension != NULL) {
206 ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
207 ak->restore_unshareable_info(loader_data, protection_domain, CHECK);
208 }
209 }
210
211 // Printing
212
213 void ArrayKlass::print_on(outputStream* st) const {
214 assert(is_klass(), "must be klass");
215 Klass::print_on(st);
216 }
217
218 void ArrayKlass::print_value_on(outputStream* st) const {
219 assert(is_klass(), "must be klass");
220 for(int index = 0; index < dimension(); index++) {
221 st->print("[]");
222 }
223 }
224
225 void ArrayKlass::oop_print_on(oop obj, outputStream* st) {
226 assert(obj->is_array(), "must be array");
227 Klass::oop_print_on(obj, st);
228 st->print_cr(" - length: %d", arrayOop(obj)->length());
229 }
230
231
232 // Verification
233
234 void ArrayKlass::verify_on(outputStream* st) {
235 Klass::verify_on(st);
236 }
237
238 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) {
239 guarantee(obj->is_array(), "must be array");
240 arrayOop a = arrayOop(obj);
241 guarantee(a->length() >= 0, "array with negative length?");
242 }