1 /*
2 * Copyright (c) 1997, 2025, 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 "cds/aotMetaspace.hpp"
26 #include "cds/cdsConfig.hpp"
27 #include "classfile/javaClasses.hpp"
28 #include "classfile/moduleEntry.hpp"
29 #include "classfile/vmClasses.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "gc/shared/collectedHeap.inline.hpp"
32 #include "jvmtifiles/jvmti.h"
33 #include "memory/metaspaceClosure.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "memory/universe.hpp"
36 #include "oops/arrayKlass.inline.hpp"
37 #include "oops/arrayOop.hpp"
38 #include "oops/instanceKlass.hpp"
39 #include "oops/klass.inline.hpp"
40 #include "oops/objArrayOop.hpp"
41 #include "oops/oop.inline.hpp"
42 #include "runtime/handles.inline.hpp"
43
44 ArrayKlass::ArrayKlass() {
45 assert(CDSConfig::is_dumping_static_archive() || CDSConfig::is_using_archive(), "only for CDS");
46 }
47
48 int ArrayKlass::static_size(int header_size) {
49 // size of an array klass object
50 assert(header_size <= InstanceKlass::header_size(), "bad header size");
51 // If this assert fails, see comments in base_create_array_klass.
52 header_size = InstanceKlass::header_size();
53 int vtable_len = Universe::base_vtable_size();
54 int size = header_size + vtable_len;
55 return align_metadata_size(size);
56 }
57
58
59 InstanceKlass* ArrayKlass::java_super() const {
60 if (super() == nullptr) return nullptr; // bootstrap case
61 // Array klasses have primary supertypes which are not reported to Java.
62 // Example super chain: String[][] -> Object[][] -> Object[] -> Object
63 return vmClasses::Object_klass();
64 }
65
66
67 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
68 ShouldNotReachHere();
69 return nullptr;
70 }
71
72 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
73 Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
74 // There are no fields in an array klass but look to the super class (Object)
75 assert(super(), "super klass must be present");
76 return super()->find_field(name, sig, fd);
77 }
78
79 Method* ArrayKlass::uncached_lookup_method(const Symbol* name,
80 const Symbol* signature,
81 OverpassLookupMode overpass_mode,
82 PrivateLookupMode private_mode) const {
83 // There are no methods in an array klass but the super class (Object) has some
84 assert(super(), "super klass must be present");
85 // Always ignore overpass methods in superclasses, although technically the
86 // super klass of an array, (j.l.Object) should not have
87 // any overpass methods present.
88 return super()->uncached_lookup_method(name, signature, OverpassLookupMode::skip, private_mode);
89 }
90
91 ArrayKlass::ArrayKlass(Symbol* name, KlassKind kind) : 92 Klass(kind),
93 _dimension(1),
94 _higher_dimension(nullptr),
95 _lower_dimension(nullptr) {
96 // Arrays don't add any new methods, so their vtable is the same size as
97 // the vtable of klass Object.
98 set_vtable_length(Universe::base_vtable_size());
99 set_name(name);
100 set_super(Universe::is_bootstrapping() ? nullptr : vmClasses::Object_klass());
101 set_layout_helper(Klass::_lh_neutral_value);
102 // All arrays are considered to be cloneable (See JLS 20.1.5)
103 set_is_cloneable_fast();
104 JFR_ONLY(INIT_ID(this);)
105 log_array_class_load(this);
106 }
107
108
109 // Initialization of vtables and mirror object is done separately from base_create_array_klass,
110 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup.
111 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module_entry, TRAPS) {
112 k->initialize_supers(super_klass, nullptr, CHECK);
113 k->vtable().initialize_vtable();
114
115 // During bootstrapping, before java.base is defined, the module_entry may not be present yet.
116 // These classes will be put on a fixup list and their module fields will be patched once
117 // java.base is defined.
118 assert((module_entry != nullptr) || ((module_entry == nullptr) && !ModuleEntryTable::javabase_defined()),
119 "module entry not available post " JAVA_BASE_NAME " definition");
120 oop module_oop = (module_entry != nullptr) ? module_entry->module_oop() : (oop)nullptr;
121 java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(THREAD, module_oop), Handle(), Handle(), CHECK);
122 }
123
124 ArrayKlass* ArrayKlass::array_klass(int n, TRAPS) {
125
126 assert(dimension() <= n, "check order of chain");
127 int dim = dimension();
128 if (dim == n) return this;
129
130 // lock-free read needs acquire semantics
131 if (higher_dimension_acquire() == nullptr) {
132
133 // Ensure atomic creation of higher dimensions
134 RecursiveLocker rl(MultiArray_lock, THREAD);
135
136 if (higher_dimension() == nullptr) {
137 // Create multi-dim klass object and link them together
138 ObjArrayKlass* ak =139 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL);
140 // use 'release' to pair with lock-free load
141 release_set_higher_dimension(ak);
142 assert(ak->lower_dimension() == this, "lower dimension mismatch");
143 }
144 }
145
146 ObjArrayKlass* ak = higher_dimension();
147 assert(ak != nullptr, "should be set");
148 THREAD->check_possible_safepoint();
149 return ak->array_klass(n, THREAD);
150 }
151
152 ArrayKlass* ArrayKlass::array_klass_or_null(int n) {
153
154 assert(dimension() <= n, "check order of chain");
155 int dim = dimension();
156 if (dim == n) return this;
157
158 // lock-free read needs acquire semantics
159 if (higher_dimension_acquire() == nullptr) {
160 return nullptr;
161 }
162
163 ObjArrayKlass *ak = higher_dimension();
164 return ak->array_klass_or_null(n);
165 }
166
167 ArrayKlass* ArrayKlass::array_klass(TRAPS) {
168 return array_klass(dimension() + 1, THREAD);
169 }
170
171 ArrayKlass* ArrayKlass::array_klass_or_null() {
172 return array_klass_or_null(dimension() + 1);
173 }
174
175
176 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots,
177 Array<InstanceKlass*>* transitive_interfaces) {
178 // interfaces = { cloneable_klass, serializable_klass };
179 assert(num_extra_slots == 0, "sanity of primitive array type");
180 assert(transitive_interfaces == nullptr, "sanity");
181 // Must share this for correct bootstrapping!
182 set_secondary_supers(Universe::the_array_interfaces_array(),
183 Universe::the_array_interfaces_bitmap());
184 return nullptr;
185 }
186
187 // JVMTI support
188
189 jint ArrayKlass::jvmti_class_status() const {
190 return JVMTI_CLASS_STATUS_ARRAY;
191 }
192
193 void ArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
194 Klass::metaspace_pointers_do(it);
195
196 ResourceMark rm;
197 log_trace(aot)("Iter(ArrayKlass): %p (%s)", this, external_name());
198
199 // need to cast away volatile
200 it->push((Klass**)&_higher_dimension);
201 it->push((Klass**)&_lower_dimension);
202 }
203
204 #if INCLUDE_CDS
205 void ArrayKlass::remove_unshareable_info() {
206 Klass::remove_unshareable_info();
207 if (_higher_dimension != nullptr) {
208 ArrayKlass *ak = higher_dimension();
209 ak->remove_unshareable_info();
210 }
211 }
212
213 void ArrayKlass::remove_java_mirror() {
214 Klass::remove_java_mirror();
215 if (_higher_dimension != nullptr) {
216 ArrayKlass *ak = higher_dimension();
217 ak->remove_java_mirror();
218 }
219 }
220
221 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
222 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
223 // Klass recreates the component mirror also
224
225 if (_higher_dimension != nullptr) {
226 ArrayKlass *ak = higher_dimension();
227 log_array_class_load(ak);
228 ak->restore_unshareable_info(loader_data, protection_domain, CHECK);
229 }
230 }
231
232 void ArrayKlass::cds_print_value_on(outputStream* st) const {
233 assert(is_klass(), "must be klass");
234 st->print(" - array: %s", internal_name());
235 if (_higher_dimension != nullptr) {
236 ArrayKlass* ak = higher_dimension();
237 st->cr();
238 ak->cds_print_value_on(st);
239 }
240 }
241 #endif // INCLUDE_CDS
242
243 void ArrayKlass::log_array_class_load(Klass* k) {
244 LogTarget(Debug, class, load, array) lt;
245 if (lt.is_enabled()) {
246 LogStream ls(lt);
247 ResourceMark rm;
248 ls.print("%s", k->name()->as_klass_external_name());
249 if (AOTMetaspace::in_aot_cache_dynamic_region((void*)k)) {
250 ls.print(" source: shared objects file (top)");
251 } else if (AOTMetaspace::in_aot_cache_static_region((void*)k)) {
252 ls.print(" source: shared objects file");
253 }
254 ls.cr();
255 }
256 }
257
258 // Printing
259
260 void ArrayKlass::print_on(outputStream* st) const {
261 assert(is_klass(), "must be klass");
262 Klass::print_on(st);
263 }
264
265 void ArrayKlass::print_value_on(outputStream* st) const {
266 assert(is_klass(), "must be klass");
267 for(int index = 0; index < dimension(); index++) {
268 st->print("[]");
269 }
270 }
271
272 void ArrayKlass::oop_print_on(oop obj, outputStream* st) {
273 assert(obj->is_array(), "must be array");
274 Klass::oop_print_on(obj, st);
275 st->print_cr(" - length: %d", arrayOop(obj)->length());
276 }
277
278
279 // Verification
280
281 void ArrayKlass::verify_on(outputStream* st) {
282 Klass::verify_on(st);
283 }
284
285 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) {
286 guarantee(obj->is_array(), "must be array");
287 arrayOop a = arrayOop(obj);
288 guarantee(a->length() >= 0, "array with negative length?");
289 }
--- EOF ---