1 /*
2 * Copyright (c) 1997, 2023, 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 "cds/metaspaceShared.hpp"
27 #include "classfile/javaClasses.hpp"
28 #include "classfile/moduleEntry.hpp"
29 #include "classfile/symbolTable.hpp"
30 #include "classfile/vmClasses.hpp"
31 #include "classfile/vmSymbols.hpp"
32 #include "gc/shared/collectedHeap.inline.hpp"
33 #include "jvmtifiles/jvmti.h"
34 #include "memory/metaspaceClosure.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "memory/universe.hpp"
37 #include "oops/arrayKlass.hpp"
38 #include "oops/objArrayKlass.hpp"
39 #include "oops/arrayOop.hpp"
40 #include "oops/instanceKlass.hpp"
41 #include "oops/klass.inline.hpp"
42 #include "oops/objArrayOop.hpp"
43 #include "oops/oop.inline.hpp"
44 #include "runtime/handles.inline.hpp"
45
46 int ArrayKlass::static_size(int header_size) {
47 // size of an array klass object
48 assert(header_size <= InstanceKlass::header_size(), "bad header size");
49 // If this assert fails, see comments in base_create_array_klass.
50 header_size = InstanceKlass::header_size();
51 int vtable_len = Universe::base_vtable_size();
52 int size = header_size + vtable_len;
53 return align_metadata_size(size);
54 }
55
56
57 InstanceKlass* ArrayKlass::java_super() const {
58 if (super() == nullptr) return nullptr; // bootstrap case
59 // Array klasses have primary supertypes which are not reported to Java.
60 // Example super chain: String[][] -> Object[][] -> Object[] -> Object
61 return vmClasses::Object_klass();
62 }
63
64
65 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
66 ShouldNotReachHere();
67 return nullptr;
68 }
69
70 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
71 Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
72 // There are no fields in an array klass but look to the super class (Object)
73 assert(super(), "super klass must be present");
74 return super()->find_field(name, sig, fd);
75 }
76
77 Method* ArrayKlass::uncached_lookup_method(const Symbol* name,
78 const Symbol* signature,
79 OverpassLookupMode overpass_mode,
80 PrivateLookupMode private_mode) const {
81 // There are no methods in an array klass but the super class (Object) has some
82 assert(super(), "super klass must be present");
83 // Always ignore overpass methods in superclasses, although technically the
84 // super klass of an array, (j.l.Object) should not have
85 // any overpass methods present.
86 return super()->uncached_lookup_method(name, signature, OverpassLookupMode::skip, private_mode);
87 }
88
89 ArrayKlass::ArrayKlass(Symbol* name, KlassKind kind) :
90 Klass(kind),
91 _dimension(1),
92 _higher_dimension(nullptr),
93 _lower_dimension(nullptr) {
94 // Arrays don't add any new methods, so their vtable is the same size as
95 // the vtable of klass Object.
96 set_vtable_length(Universe::base_vtable_size());
97 set_name(name);
98 set_super(Universe::is_bootstrapping() ? nullptr : vmClasses::Object_klass());
99 set_layout_helper(Klass::_lh_neutral_value);
100 set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5)
101 JFR_ONLY(INIT_ID(this);)
102 log_array_class_load(this);
103 }
104
105 Symbol* ArrayKlass::create_element_klass_array_name(Klass* element_klass, bool qdesc, TRAPS) {
106 ResourceMark rm(THREAD);
107 Symbol* name = nullptr;
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++] = JVM_SIGNATURE_ARRAY;
113 if (element_klass->is_instance_klass()) { // it could be an array or simple type
114 if (qdesc) {
115 new_str[idx++] = JVM_SIGNATURE_PRIMITIVE_OBJECT;
116 } else {
117 new_str[idx++] = JVM_SIGNATURE_CLASS;
118 }
119 }
120 memcpy(&new_str[idx], name_str, len * sizeof(char));
121 idx += len;
122 if (element_klass->is_instance_klass()) {
123 new_str[idx++] = JVM_SIGNATURE_ENDCLASS;
124 }
125 new_str[idx++] = '\0';
126 return SymbolTable::new_symbol(new_str);
127 }
128
129 // Initialization of vtables and mirror object is done separately from base_create_array_klass,
130 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup.
131 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module_entry, TRAPS) {
132 k->initialize_supers(super_klass, nullptr, CHECK);
133 k->vtable().initialize_vtable();
134
135 // During bootstrapping, before java.base is defined, the module_entry may not be present yet.
136 // These classes will be put on a fixup list and their module fields will be patched once
137 // java.base is defined.
138 assert((module_entry != nullptr) || ((module_entry == nullptr) && !ModuleEntryTable::javabase_defined()),
139 "module entry not available post " JAVA_BASE_NAME " definition");
140 oop module = (module_entry != nullptr) ? module_entry->module() : (oop)nullptr;
141 java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(THREAD, module), Handle(), Handle(), CHECK);
142 }
143
144 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots,
145 Array<InstanceKlass*>* transitive_interfaces) {
146 // interfaces = { cloneable_klass, serializable_klass };
147 assert(num_extra_slots == 0, "sanity of primitive array type");
148 assert(transitive_interfaces == nullptr, "sanity");
149 // Must share this for correct bootstrapping!
150 set_secondary_supers(Universe::the_array_interfaces_array());
151 return nullptr;
152 }
153
154 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) {
155 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_ARRAY), CHECK_NULL);
156 size_t size = objArrayOopDesc::object_size(length);
157 ArrayKlass* ak = array_klass(n + dimension(), CHECK_NULL);
158 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
159 /* do_zero */ true, CHECK_NULL);
160 // initialization to null not necessary, area already cleared
161 return o;
162 }
163
164 oop ArrayKlass::component_mirror() const {
165 return java_lang_Class::component_mirror(java_mirror());
166 }
167
168 jint ArrayKlass::compute_modifier_flags() 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 #if INCLUDE_CDS
190 void ArrayKlass::remove_unshareable_info() {
191 Klass::remove_unshareable_info();
192 if (_higher_dimension != nullptr) {
193 ArrayKlass *ak = higher_dimension();
194 ak->remove_unshareable_info();
195 }
196 }
197
198 void ArrayKlass::remove_java_mirror() {
199 Klass::remove_java_mirror();
200 if (_higher_dimension != nullptr) {
201 ArrayKlass *ak = higher_dimension();
202 ak->remove_java_mirror();
203 }
204 }
205
206 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
207 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
208 // Klass recreates the component mirror also
209
210 if (_higher_dimension != nullptr) {
211 ArrayKlass *ak = higher_dimension();
212 log_array_class_load(ak);
213 ak->restore_unshareable_info(loader_data, protection_domain, CHECK);
214 }
215 }
216
217 void ArrayKlass::cds_print_value_on(outputStream* st) const {
218 assert(is_klass(), "must be klass");
219 st->print(" - array: %s", internal_name());
220 if (_higher_dimension != nullptr) {
221 ArrayKlass* ak = higher_dimension();
222 st->cr();
223 ak->cds_print_value_on(st);
224 }
225 }
226 #endif // INCLUDE_CDS
227
228 void ArrayKlass::log_array_class_load(Klass* k) {
229 LogTarget(Debug, class, load, array) lt;
230 if (lt.is_enabled()) {
231 LogStream ls(lt);
232 ResourceMark rm;
233 ls.print("%s", k->name()->as_klass_external_name());
234 if (MetaspaceShared::is_shared_dynamic((void*)k)) {
235 ls.print(" source: shared objects file (top)");
236 } else if (MetaspaceShared::is_shared_static((void*)k)) {
237 ls.print(" source: shared objects file");
238 }
239 ls.cr();
240 }
241 }
242
243 // Printing
244
245 void ArrayKlass::print_on(outputStream* st) const {
246 assert(is_klass(), "must be klass");
247 Klass::print_on(st);
248 }
249
250 void ArrayKlass::print_value_on(outputStream* st) const {
251 assert(is_klass(), "must be klass");
252 for(int index = 0; index < dimension(); index++) {
253 st->print("[]");
254 }
255 }
256
257 void ArrayKlass::oop_print_on(oop obj, outputStream* st) {
258 assert(obj->is_array(), "must be array");
259 Klass::oop_print_on(obj, st);
260 st->print_cr(" - length: %d", arrayOop(obj)->length());
261 }
262
263
264 // Verification
265
266 void ArrayKlass::verify_on(outputStream* st) {
267 Klass::verify_on(st);
268 }
269
270 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) {
271 guarantee(obj->is_array(), "must be array");
272 arrayOop a = arrayOop(obj);
273 guarantee(a->length() >= 0, "array with negative length?");
274 }