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/symbolTable.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "gc/shared/collectedHeap.inline.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/objArrayKlass.hpp"
37 #include "oops/arrayOop.hpp"
38 #include "oops/instanceKlass.hpp"
39 #include "oops/objArrayOop.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "runtime/handles.inline.hpp"
42
43 int ArrayKlass::static_size(int header_size) {
44 // size of an array klass object
45 assert(header_size <= InstanceKlass::header_size(), "bad header size");
46 // If this assert fails, see comments in base_create_array_klass.
47 header_size = InstanceKlass::header_size();
48 int vtable_len = Universe::base_vtable_size();
49 int size = header_size + vtable_len;
50 return align_metadata_size(size);
51 }
52
53
54 InstanceKlass* ArrayKlass::java_super() const {
55 if (super() == NULL) return NULL; // bootstrap case
56 // Array klasses have primary supertypes which are not reported to Java.
57 // Example super chain: String[][] -> Object[][] -> Object[] -> Object
58 return SystemDictionary::Object_klass();
59 }
60
61
62 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
63 ShouldNotReachHere();
64 return NULL;
65 }
66
67 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
68 Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
69 // There are no fields in an array klass but look to the super class (Object)
70 assert(super(), "super klass must be present");
71 return super()->find_field(name, sig, fd);
72 }
73
74 Method* ArrayKlass::uncached_lookup_method(const Symbol* name,
75 const Symbol* signature,
76 OverpassLookupMode overpass_mode,
77 PrivateLookupMode private_mode) const {
78 // There are no methods in an array klass but the super class (Object) has some
79 assert(super(), "super klass must be present");
80 // Always ignore overpass methods in superclasses, although technically the
81 // super klass of an array, (j.l.Object) should not have
82 // any overpass methods present.
83 return super()->uncached_lookup_method(name, signature, Klass::skip_overpass, private_mode);
84 }
85
86 ArrayKlass::ArrayKlass(Symbol* name, KlassID id) :
87 Klass(id),
88 _dimension(1),
89 _higher_dimension(NULL),
90 _lower_dimension(NULL) {
91 // Arrays don't add any new methods, so their vtable is the same size as
92 // the vtable of klass Object.
93 set_vtable_length(Universe::base_vtable_size());
94 set_name(name);
95 set_super(Universe::is_bootstrapping() ? NULL : SystemDictionary::Object_klass());
96 set_layout_helper(Klass::_lh_neutral_value);
97 set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5)
98 JFR_ONLY(INIT_ID(this);)
99 assert(!ptr_is_value_type(this), "ArrayKlass encoded as value type");
100 }
101
102 Symbol* ArrayKlass::create_element_klass_array_name(Klass* element_klass, TRAPS) {
103 Symbol* name = NULL;
104 if (!element_klass->is_instance_klass() ||
105 (name = InstanceKlass::cast(element_klass)->array_name()) == NULL) {
106
107 ResourceMark rm(THREAD);
108 char *name_str = element_klass->name()->as_C_string();
109 int len = element_klass->name()->utf8_length();
110 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4);
111 int idx = 0;
112 new_str[idx++] = '[';
113 if (element_klass->is_instance_klass()) { // it could be an array or simple type
114 // Temporary hack, for arrays of value types, this code should be removed
115 // once value types have their own array types
116 new_str[idx++] = 'L';
117 }
118 memcpy(&new_str[idx], name_str, len * sizeof(char));
119 idx += len;
120 if (element_klass->is_instance_klass()) {
121 new_str[idx++] = ';';
122 }
123 new_str[idx++] = '\0';
124 name = SymbolTable::new_permanent_symbol(new_str, CHECK_NULL);
125 if (element_klass->is_instance_klass() || element_klass->is_value()) {
126 InstanceKlass* ik = InstanceKlass::cast(element_klass);
127 ik->set_array_name(name);
128 }
129 }
130
131 return name;
132 }
133
134 // Initialization of vtables and mirror object is done separatly from base_create_array_klass,
135 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup.
136 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module_entry, TRAPS) {
137 k->initialize_supers(super_klass, NULL, CHECK);
138 k->vtable().initialize_vtable(false, CHECK);
139
140 // During bootstrapping, before java.base is defined, the module_entry may not be present yet.
141 // These classes will be put on a fixup list and their module fields will be patched once
142 // java.base is defined.
143 assert((module_entry != NULL) || ((module_entry == NULL) && !ModuleEntryTable::javabase_defined()),
144 "module entry not available post " JAVA_BASE_NAME " definition");
145 oop module = (module_entry != NULL) ? module_entry->module() : (oop)NULL;
146 java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(THREAD, module), Handle(), CHECK);
147 }
148
149 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots,
150 Array<InstanceKlass*>* transitive_interfaces) {
151 // interfaces = { cloneable_klass, serializable_klass };
152 assert(num_extra_slots == 0, "sanity of primitive array type");
153 assert(transitive_interfaces == NULL, "sanity");
154 // Must share this for correct bootstrapping!
155 set_secondary_supers(Universe::the_array_interfaces_array());
156 return NULL;
157 }
158
159 bool ArrayKlass::compute_is_subtype_of(Klass* k) {
160 // An array is a subtype of Serializable, Clonable, and Object
161 return k == SystemDictionary::Object_klass()
162 || k == SystemDictionary::Cloneable_klass()
163 || k == SystemDictionary::Serializable_klass();
164 }
165
166 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) {
167 if (length < 0) {
168 THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length));
169 }
170 if (length > arrayOopDesc::max_array_length(T_ARRAY)) {
171 report_java_out_of_memory("Requested array size exceeds VM limit");
172 JvmtiExport::post_array_size_exhausted();
173 THROW_OOP_0(Universe::out_of_memory_error_array_size());
174 }
175 int size = objArrayOopDesc::object_size(length);
176 Klass* k = array_klass(n+dimension(), CHECK_0);
177 ArrayKlass* ak = ArrayKlass::cast(k);
178 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
179 /* do_zero */ true, CHECK_0);
180 // initialization to NULL not necessary, area already cleared
181 return o;
182 }
183
184 void ArrayKlass::array_klasses_do(void f(Klass* k, TRAPS), TRAPS) {
185 Klass* k = this;
186 // Iterate over this array klass and all higher dimensions
187 while (k != NULL) {
188 f(k, CHECK);
189 k = ArrayKlass::cast(k)->higher_dimension();
190 }
191 }
192
193 void ArrayKlass::array_klasses_do(void f(Klass* k)) {
194 Klass* k = this;
195 // Iterate over this array klass and all higher dimensions
196 while (k != NULL) {
197 f(k);
198 k = ArrayKlass::cast(k)->higher_dimension();
199 }
200 }
201
202 // JVM support
203
204 jint ArrayKlass::compute_modifier_flags(TRAPS) const {
205 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
206 }
207
208 // JVMTI support
209
210 jint ArrayKlass::jvmti_class_status() const {
211 return JVMTI_CLASS_STATUS_ARRAY;
212 }
213
214 void ArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
215 Klass::metaspace_pointers_do(it);
216
217 ResourceMark rm;
218 log_trace(cds)("Iter(ArrayKlass): %p (%s)", this, external_name());
219
220 // need to cast away volatile
221 it->push((Klass**)&_higher_dimension);
222 it->push((Klass**)&_lower_dimension);
223 }
224
225 void ArrayKlass::remove_unshareable_info() {
226 Klass::remove_unshareable_info();
227 if (_higher_dimension != NULL) {
228 ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
229 ak->remove_unshareable_info();
230 }
231 }
232
233 void ArrayKlass::remove_java_mirror() {
234 Klass::remove_java_mirror();
235 if (_higher_dimension != NULL) {
236 ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
237 ak->remove_java_mirror();
238 }
239 }
240
241 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
242 assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader");
243 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
244 // Klass recreates the component mirror also
245
246 if (_higher_dimension != NULL) {
247 ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
248 ak->restore_unshareable_info(loader_data, protection_domain, CHECK);
249 }
250 }
251
252 // Printing
253
254 void ArrayKlass::print_on(outputStream* st) const {
255 assert(is_klass(), "must be klass");
256 Klass::print_on(st);
257 }
258
259 void ArrayKlass::print_value_on(outputStream* st) const {
260 assert(is_klass(), "must be klass");
261 for(int index = 0; index < dimension(); index++) {
262 st->print("[]");
263 }
264 }
265
266 void ArrayKlass::oop_print_on(oop obj, outputStream* st) {
267 assert(obj->is_array(), "must be array");
268 Klass::oop_print_on(obj, st);
269 st->print_cr(" - length: %d", arrayOop(obj)->length());
270 }
271
272
273 // Verification
274
275 void ArrayKlass::verify_on(outputStream* st) {
276 Klass::verify_on(st);
277 }
278
279 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) {
280 guarantee(obj->is_array(), "must be array");
281 arrayOop a = arrayOop(obj);
282 guarantee(a->length() >= 0, "array with negative length?");
283 }