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 "gc/shared/gcLocker.hpp"
31 #include "jvmtifiles/jvmti.h"
32 #include "memory/metaspaceClosure.hpp"
33 #include "memory/resourceArea.hpp"
34 #include "memory/universe.hpp"
35 #include "oops/arrayKlass.hpp"
36 #include "oops/arrayOop.hpp"
37 #include "oops/instanceKlass.hpp"
38 #include "oops/objArrayOop.hpp"
39 #include "oops/oop.inline.hpp"
40 #include "runtime/handles.inline.hpp"
41
42 int ArrayKlass::static_size(int header_size) {
43 // size of an array klass object
44 assert(header_size <= InstanceKlass::header_size(), "bad header size");
45 // If this assert fails, see comments in base_create_array_klass.
46 header_size = InstanceKlass::header_size();
47 int vtable_len = Universe::base_vtable_size();
48 int size = header_size + vtable_len;
49 return align_metadata_size(size);
50 }
51
52
53 Klass* ArrayKlass::java_super() const {
54 if (super() == NULL) return NULL; // bootstrap case
55 // Array klasses have primary supertypes which are not reported to Java.
56 // Example super chain: String[][] -> Object[][] -> Object[] -> Object
57 return SystemDictionary::Object_klass();
58 }
59
60
61 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
62 ShouldNotReachHere();
63 return NULL;
64 }
65
66 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
67 Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
68 // There are no fields in an array klass but look to the super class (Object)
69 assert(super(), "super klass must be present");
70 return super()->find_field(name, sig, fd);
71 }
72
73 Method* ArrayKlass::uncached_lookup_method(const Symbol* name,
74 const Symbol* signature,
75 OverpassLookupMode overpass_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);
82 }
83
84 ArrayKlass::ArrayKlass(Symbol* name) :
85 _dimension(1),
86 _higher_dimension(NULL),
87 _lower_dimension(NULL) {
88 // Arrays don't add any new methods, so their vtable is the same size as
89 // the vtable of klass Object.
90 set_vtable_length(Universe::base_vtable_size());
91 set_name(name);
92 set_super(Universe::is_bootstrapping() ? (Klass*)NULL : SystemDictionary::Object_klass());
93 set_layout_helper(Klass::_lh_neutral_value);
94 set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5)
95 TRACE_INIT_ID(this);
96 }
97
98
99 // Initialization of vtables and mirror object is done separatly from base_create_array_klass,
100 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup.
101 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module_entry, TRAPS) {
102 ResourceMark rm(THREAD);
103 k->initialize_supers(super_klass, 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 // interfaces = { cloneable_klass, serializable_klass };
117 assert(num_extra_slots == 0, "sanity of primitive array type");
118 // Must share this for correct bootstrapping!
119 set_secondary_supers(Universe::the_array_interfaces_array());
120 return NULL;
121 }
122
123 bool ArrayKlass::compute_is_subtype_of(Klass* k) {
124 // An array is a subtype of Serializable, Clonable, and Object
125 return k == SystemDictionary::Object_klass()
126 || k == SystemDictionary::Cloneable_klass()
127 || k == SystemDictionary::Serializable_klass();
128 }
129
130 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) {
131 if (length < 0) {
132 THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
133 }
134 if (length > arrayOopDesc::max_array_length(T_ARRAY)) {
135 report_java_out_of_memory("Requested array size exceeds VM limit");
136 JvmtiExport::post_array_size_exhausted();
137 THROW_OOP_0(Universe::out_of_memory_error_array_size());
138 }
139 int size = objArrayOopDesc::object_size(length);
140 Klass* k = array_klass(n+dimension(), CHECK_0);
141 ArrayKlass* ak = ArrayKlass::cast(k);
142 objArrayOop o =
143 (objArrayOop)CollectedHeap::array_allocate(ak, size, length, CHECK_0);
144 // initialization to NULL not necessary, area already cleared
145 return o;
146 }
147
148 void ArrayKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
149 Klass* k = this;
150 // Iterate over this array klass and all higher dimensions
151 while (k != NULL) {
152 f(k, CHECK);
153 k = ArrayKlass::cast(k)->higher_dimension();
154 }
155 }
156
157 void ArrayKlass::array_klasses_do(void f(Klass* k)) {
158 Klass* k = this;
159 // Iterate over this array klass and all higher dimensions
160 while (k != NULL) {
161 f(k);
162 k = ArrayKlass::cast(k)->higher_dimension();
163 }
164 }
165
166 // JVM support
167
168 jint ArrayKlass::compute_modifier_flags(TRAPS) const {
169 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
170 }
171
172 // JVMTI support
173
174 jint ArrayKlass::jvmti_class_status() const {
175 return JVMTI_CLASS_STATUS_ARRAY;
176 }
177
178 void ArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
179 Klass::metaspace_pointers_do(it);
180
181 ResourceMark rm;
182 log_trace(cds)("Iter(ArrayKlass): %p (%s)", this, external_name());
183
184 // need to cast away volatile
185 it->push((Klass**)&_higher_dimension);
186 it->push((Klass**)&_lower_dimension);
187 }
188
189 void ArrayKlass::remove_unshareable_info() {
190 Klass::remove_unshareable_info();
191 if (_higher_dimension != NULL) {
192 ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
193 ak->remove_unshareable_info();
194 }
195 }
196
197 void ArrayKlass::remove_java_mirror() {
198 Klass::remove_java_mirror();
199 if (_higher_dimension != NULL) {
200 ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
201 ak->remove_java_mirror();
202 }
203 }
204
205 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
206 assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader");
207 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
208 // Klass recreates the component mirror also
209
210 if (_higher_dimension != NULL) {
211 ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
212 ak->restore_unshareable_info(loader_data, protection_domain, CHECK);
213 }
214 }
215
216 // Printing
217
218 void ArrayKlass::print_on(outputStream* st) const {
219 assert(is_klass(), "must be klass");
220 Klass::print_on(st);
221 }
222
223 void ArrayKlass::print_value_on(outputStream* st) const {
224 assert(is_klass(), "must be klass");
225 for(int index = 0; index < dimension(); index++) {
226 st->print("[]");
227 }
228 }
229
230 void ArrayKlass::oop_print_on(oop obj, outputStream* st) {
231 assert(obj->is_array(), "must be array");
232 Klass::oop_print_on(obj, st);
233 st->print_cr(" - length: %d", arrayOop(obj)->length());
234 }
235
236
237 // Verification
238
239 void ArrayKlass::verify_on(outputStream* st) {
240 Klass::verify_on(st);
241 }
242
243 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) {
244 guarantee(obj->is_array(), "must be array");
245 arrayOop a = arrayOop(obj);
246 guarantee(a->length() >= 0, "array with negative length?");
247 }