1 /*
2 * Copyright (c) 1997, 2019, 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/moduleEntry.hpp"
28 #include "classfile/symbolTable.hpp"
29 #include "classfile/systemDictionary.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.hpp"
37 #include "oops/objArrayKlass.hpp"
38 #include "oops/arrayOop.hpp"
39 #include "oops/instanceKlass.hpp"
40 #include "oops/objArrayOop.hpp"
41 #include "oops/oop.inline.hpp"
42 #include "runtime/handles.inline.hpp"
43
44 int ArrayKlass::static_size(int header_size) {
45 // size of an array klass object
46 assert(header_size <= InstanceKlass::header_size(), "bad header size");
47 // If this assert fails, see comments in base_create_array_klass.
48 header_size = InstanceKlass::header_size();
49 int vtable_len = Universe::base_vtable_size();
50 int size = header_size + vtable_len;
51 return align_metadata_size(size);
52 }
53
54
55 InstanceKlass* ArrayKlass::java_super() const {
56 if (super() == NULL) return NULL; // bootstrap case
57 // Array klasses have primary supertypes which are not reported to Java.
58 // Example super chain: String[][] -> Object[][] -> Object[] -> Object
59 return SystemDictionary::Object_klass();
60 }
61
62
63 oop ArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
64 ShouldNotReachHere();
65 return NULL;
66 }
67
68 // find field according to JVM spec 5.4.3.2, returns the klass in which the field is defined
69 Klass* ArrayKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
70 // There are no fields in an array klass but look to the super class (Object)
71 assert(super(), "super klass must be present");
72 return super()->find_field(name, sig, fd);
73 }
74
75 Method* ArrayKlass::uncached_lookup_method(const Symbol* name,
76 const Symbol* signature,
77 OverpassLookupMode overpass_mode,
78 PrivateLookupMode private_mode) const {
79 // There are no methods in an array klass but the super class (Object) has some
80 assert(super(), "super klass must be present");
81 // Always ignore overpass methods in superclasses, although technically the
82 // super klass of an array, (j.l.Object) should not have
83 // any overpass methods present.
84 return super()->uncached_lookup_method(name, signature, Klass::skip_overpass, private_mode);
85 }
86
87 ArrayKlass::ArrayKlass(Symbol* name, KlassID id) :
88 Klass(id),
89 _dimension(1),
90 _higher_dimension(NULL),
91 _lower_dimension(NULL) {
92 // Arrays don't add any new methods, so their vtable is the same size as
93 // the vtable of klass Object.
94 set_vtable_length(Universe::base_vtable_size());
95 set_name(name);
96 set_super(Universe::is_bootstrapping() ? NULL : SystemDictionary::Object_klass());
97 set_layout_helper(Klass::_lh_neutral_value);
98 set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5)
99 JFR_ONLY(INIT_ID(this);)
100 }
101
102 Symbol* ArrayKlass::create_element_klass_array_name(bool is_qtype, Klass* element_klass, TRAPS) {
103 Symbol* name = NULL;
104 if (!element_klass->is_instance_klass() || is_qtype ||
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 if (is_qtype) {
115 new_str[idx++] = 'Q';
116 } else {
117 new_str[idx++] = 'L';
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++] = ';';
124 }
125 new_str[idx++] = '\0';
126 name = SymbolTable::new_permanent_symbol(new_str, CHECK_NULL);
127 if (element_klass->is_instance_klass() && (!is_qtype)) {
128 InstanceKlass* ik = InstanceKlass::cast(element_klass);
129 ik->set_array_name(name); // CMH: only cache and deref array_name for L-type...missing for Q-type
130 }
131 }
132
133 return name;
134 }
135
136 // Initialization of vtables and mirror object is done separatly from base_create_array_klass,
137 // since a GC can happen. At this point all instance variables of the ArrayKlass must be setup.
138 void ArrayKlass::complete_create_array_klass(ArrayKlass* k, Klass* super_klass, ModuleEntry* module_entry, TRAPS) {
139 k->initialize_supers(super_klass, NULL, CHECK);
140 k->vtable().initialize_vtable(false, CHECK);
141
142 // During bootstrapping, before java.base is defined, the module_entry may not be present yet.
143 // These classes will be put on a fixup list and their module fields will be patched once
144 // java.base is defined.
145 assert((module_entry != NULL) || ((module_entry == NULL) && !ModuleEntryTable::javabase_defined()),
146 "module entry not available post " JAVA_BASE_NAME " definition");
147 oop module = (module_entry != NULL) ? module_entry->module() : (oop)NULL;
148 java_lang_Class::create_mirror(k, Handle(THREAD, k->class_loader()), Handle(THREAD, module), Handle(), CHECK);
149 }
150
151 GrowableArray<Klass*>* ArrayKlass::compute_secondary_supers(int num_extra_slots,
152 Array<InstanceKlass*>* transitive_interfaces) {
153 // interfaces = { cloneable_klass, serializable_klass };
154 assert(num_extra_slots == 0, "sanity of primitive array type");
155 assert(transitive_interfaces == NULL, "sanity");
156 // Must share this for correct bootstrapping!
157 set_secondary_supers(Universe::the_array_interfaces_array());
158 return NULL;
159 }
160
161 objArrayOop ArrayKlass::allocate_arrayArray(int n, int length, TRAPS) {
162 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_ARRAY), CHECK_0);
163 int size = objArrayOopDesc::object_size(length);
164 Klass* k = array_klass(FieldType::get_array_storage_properties(name()), n+dimension(), CHECK_0);
165 ArrayKlass* ak = ArrayKlass::cast(k);
166 objArrayOop o = (objArrayOop)Universe::heap()->array_allocate(ak, size, length,
167 /* do_zero */ true, CHECK_0);
168 // initialization to NULL not necessary, area already cleared
169 return o;
170 }
171
172 void ArrayKlass::array_klasses_do(void f(Klass* k)) {
173 Klass* k = this;
174 // Iterate over this array klass and all higher dimensions
175 while (k != NULL) {
176 f(k);
177 k = ArrayKlass::cast(k)->higher_dimension();
178 }
179 }
180
181 oop ArrayKlass::component_mirror() const {
182 return java_lang_Class::component_mirror(java_mirror());
183 }
184
185 // JVM support
186
187 jint ArrayKlass::compute_modifier_flags(TRAPS) const {
188 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
189 }
190
191 // JVMTI support
192
193 jint ArrayKlass::jvmti_class_status() const {
194 return JVMTI_CLASS_STATUS_ARRAY;
195 }
196
197 void ArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
198 Klass::metaspace_pointers_do(it);
199
200 ResourceMark rm;
201 log_trace(cds)("Iter(ArrayKlass): %p (%s)", this, external_name());
202
203 // need to cast away volatile
204 it->push((Klass**)&_higher_dimension);
205 it->push((Klass**)&_lower_dimension);
206 }
207
208 void ArrayKlass::remove_unshareable_info() {
209 Klass::remove_unshareable_info();
210 if (_higher_dimension != NULL) {
211 ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
212 ak->remove_unshareable_info();
213 }
214 }
215
216 void ArrayKlass::remove_java_mirror() {
217 Klass::remove_java_mirror();
218 if (_higher_dimension != NULL) {
219 ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
220 ak->remove_java_mirror();
221 }
222 }
223
224 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
225 assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader");
226 Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
227 // Klass recreates the component mirror also
228
229 if (_higher_dimension != NULL) {
230 ArrayKlass *ak = ArrayKlass::cast(higher_dimension());
231 ak->restore_unshareable_info(loader_data, protection_domain, CHECK);
232 }
233 }
234
235 // Printing
236
237 void ArrayKlass::print_on(outputStream* st) const {
238 assert(is_klass(), "must be klass");
239 Klass::print_on(st);
240 }
241
242 void ArrayKlass::print_value_on(outputStream* st) const {
243 assert(is_klass(), "must be klass");
244 for(int index = 0; index < dimension(); index++) {
245 st->print("[]");
246 }
247 }
248
249 void ArrayKlass::oop_print_on(oop obj, outputStream* st) {
250 assert(obj->is_array(), "must be array");
251 Klass::oop_print_on(obj, st);
252 st->print_cr(" - length: %d", arrayOop(obj)->length());
253 }
254
255
256 // Verification
257
258 void ArrayKlass::verify_on(outputStream* st) {
259 Klass::verify_on(st);
260 }
261
262 void ArrayKlass::oop_verify_on(oop obj, outputStream* st) {
263 guarantee(obj->is_array(), "must be array");
264 arrayOop a = arrayOop(obj);
265 guarantee(a->length() >= 0, "array with negative length?");
266 }