1 /*
2 * Copyright (c) 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 "classfile/moduleEntry.hpp"
26 #include "classfile/packageEntry.hpp"
27 #include "classfile/symbolTable.hpp"
28 #include "classfile/vmClasses.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "gc/shared/collectedHeap.inline.hpp"
31 #include "memory/iterator.inline.hpp"
32 #include "memory/metadataFactory.hpp"
33 #include "memory/metaspaceClosure.hpp"
34 #include "memory/oopFactory.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "memory/universe.hpp"
37 #include "oops/arrayKlass.hpp"
38 #include "oops/instanceKlass.hpp"
39 #include "oops/klass.inline.hpp"
40 #include "oops/markWord.hpp"
41 #include "oops/objArrayKlass.inline.hpp"
42 #include "oops/oop.inline.hpp"
43 #include "oops/oopCast.inline.hpp"
44 #include "oops/refArrayKlass.inline.hpp"
45 #include "oops/refArrayOop.inline.hpp"
46 #include "oops/symbol.hpp"
47 #include "runtime/handles.inline.hpp"
48 #include "runtime/mutexLocker.hpp"
49 #include "utilities/macros.hpp"
50
51 RefArrayKlass *RefArrayKlass::allocate_klass(ClassLoaderData* loader_data, int n,
52 Klass* k, Symbol *name, ArrayProperties props,
53 TRAPS) {
54 assert(RefArrayKlass::header_size() <= InstanceKlass::header_size(),
55 "array klasses must be same size as InstanceKlass");
56
57 int size = ArrayKlass::static_size(RefArrayKlass::header_size());
58
59 return new (loader_data, size, THREAD) RefArrayKlass(n, k, name, props);
60 }
61
62 RefArrayKlass* RefArrayKlass::allocate_refArray_klass(ClassLoaderData* loader_data, int n,
63 Klass* element_klass, ArrayProperties props,
64 TRAPS) {
65 assert(!props.is_null_restricted() || (n == 1 && element_klass->is_inline_klass()),
66 "null-free unsupported");
67
68 // Eagerly allocate the direct array supertype.
69 Klass* super_klass = nullptr;
70 if (!Universe::is_bootstrapping() || vmClasses::Object_klass_is_loaded()) {
71 assert(MultiArray_lock->holds_lock(THREAD),
72 "must hold lock after bootstrapping");
73 Klass* element_super = element_klass->super();
74 super_klass = element_klass->array_klass(CHECK_NULL);
75 }
76
77 // Create type name for klass.
78 Symbol* name = create_element_klass_array_name(THREAD, element_klass);
79
80 // Initialize instance variables
81 RefArrayKlass* oak = RefArrayKlass::allocate_klass(loader_data, n, element_klass,
82 name, props, CHECK_NULL);
83
84 ModuleEntry* module = oak->module();
85 assert(module != nullptr, "No module entry for array");
86
87 // Call complete_create_array_klass after all instance variables has been
88 // initialized.
89 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_NULL);
90
91 // Add all classes to our internal class loader list here,
92 // including classes in the bootstrap (null) class loader.
93 // Do this step after creating the mirror so that if the
94 // mirror creation fails, loaded_classes_do() doesn't find
95 // an array class without a mirror.
96 loader_data->add_class(oak);
97
98 return oak;
99 }
100
101 RefArrayKlass::RefArrayKlass(int n, Klass* element_klass, Symbol* name,
102 ArrayProperties props)
103 : ObjArrayKlass(n, element_klass, name, Kind, props) {
104 assert(is_refArray_klass(), "sanity");
105 }
106
107 size_t RefArrayKlass::oop_size(oop obj) const {
108 // In this assert, we cannot safely access the Klass* with compact headers,
109 // because size_given_klass() calls oop_size() on objects that might be
110 // concurrently forwarded, which would overwrite the Klass*.
111 assert(UseCompactObjectHeaders || obj->is_refArray(), "must be a reference array");
112 return refArrayOop(obj)->object_size();
113 }
114
115 refArrayOop RefArrayKlass::allocate_instance(int length, TRAPS) {
116 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
117 size_t size = refArrayOopDesc::object_size(length);
118 oop array = Universe::heap()->array_allocate(
119 this, size, length, /* do_zero */ true, CHECK_NULL);
120 return oop_cast<refArrayOop>(array);
121 }
122
123 static void throw_array_null_pointer_store_exception(arrayOop src, arrayOop dst, TRAPS) {
124 ResourceMark rm(THREAD);
125 Klass* bound = ObjArrayKlass::cast(dst->klass())->element_klass();
126 stringStream ss;
127 ss.print("arraycopy: can not copy null values into %s[]",
128 bound->external_name());
129 THROW_MSG(vmSymbols::java_lang_NullPointerException(), ss.as_string());
130 }
131
132 static void throw_array_store_exception(arrayOop src, arrayOop dst, TRAPS) {
133 ResourceMark rm(THREAD);
134 Klass* bound = ObjArrayKlass::cast(dst->klass())->element_klass();
135 Klass* stype = ObjArrayKlass::cast(src->klass())->element_klass();
136 stringStream ss;
137 if (!bound->is_subtype_of(stype)) {
138 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
139 stype->external_name(), bound->external_name());
140 } else {
141 // oop_arraycopy should return the index in the source array that
142 // contains the problematic oop.
143 ss.print("arraycopy: element type mismatch: can not cast one of the elements"
144 " of %s[] to the type of the destination array, %s",
145 stype->external_name(), bound->external_name());
146 }
147 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
148 }
149
150 // Either oop or narrowOop depending on UseCompressedOops.
151 void RefArrayKlass::do_copy(arrayOop s, size_t src_offset, arrayOop d,
152 size_t dst_offset, int length, TRAPS) {
153 if (s == d) {
154 // since source and destination are equal we do not need conversion checks.
155 assert(length > 0, "sanity check");
156 OopCopyResult result = ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
157 assert(result == OopCopyResult::ok, "Should never fail");
158 } else {
159 // Perform null check if dst is null-free but src has no such guarantee
160 bool null_check = ((!s->klass()->is_null_free_array_klass()) &&
161 d->klass()->is_null_free_array_klass());
162 // We have to make sure all elements conform to the destination array
163 Klass *bound = RefArrayKlass::cast(d->klass())->element_klass();
164 Klass *stype = RefArrayKlass::cast(s->klass())->element_klass();
165 bool type_check = stype != bound && !stype->is_subtype_of(bound);
166
167 auto arraycopy = [&] {
168 if (type_check) {
169 if (null_check) {
170 return ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST | ARRAYCOPY_NOTNULL>::
171 oop_arraycopy(s, src_offset, d, dst_offset, length);
172 } else {
173 return ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::
174 oop_arraycopy(s, src_offset, d, dst_offset, length);
175 }
176 } else {
177 if (null_check) {
178 return ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_NOTNULL>::
179 oop_arraycopy(s, src_offset, d, dst_offset, length);
180 } else {
181 return ArrayAccess<ARRAYCOPY_DISJOINT>::
182 oop_arraycopy(s, src_offset, d, dst_offset, length);
183 }
184 }
185 };
186
187 OopCopyResult result = arraycopy();
188
189 switch (result) {
190 case OopCopyResult::ok:
191 // Done
192 break;
193 case OopCopyResult::failed_check_class_cast:
194 throw_array_store_exception(s, d, JavaThread::current());
195 break;
196 case OopCopyResult::failed_check_null:
197 throw_array_null_pointer_store_exception(s, d, JavaThread::current());
198 break;
199 default:
200 ShouldNotReachHere();
201 }
202 }
203 }
204
205 void RefArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos,
206 int length, TRAPS) {
207 assert(s->is_refArray(), "must be a reference array");
208
209 if (UseArrayFlattening && d->is_flatArray()) {
210 FlatArrayKlass::cast(d->klass())->copy_array(s, src_pos, d, dst_pos, length, THREAD);
211 return;
212 }
213
214 if (!d->is_refArray()) {
215 ResourceMark rm(THREAD);
216 stringStream ss;
217 if (d->is_typeArray()) {
218 ss.print(
219 "arraycopy: type mismatch: can not copy object array[] into %s[]",
220 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
221 } else {
222 ss.print("arraycopy: destination type %s is not an array",
223 d->klass()->external_name());
224 }
225 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
226 }
227
228 // Check is all offsets and lengths are non negative
229 if (src_pos < 0 || dst_pos < 0 || length < 0) {
230 // Pass specific exception reason.
231 ResourceMark rm(THREAD);
232 stringStream ss;
233 if (src_pos < 0) {
234 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
235 src_pos, s->length());
236 } else if (dst_pos < 0) {
237 ss.print(
238 "arraycopy: destination index %d out of bounds for object array[%d]",
239 dst_pos, d->length());
240 } else {
241 ss.print("arraycopy: length %d is negative", length);
242 }
243 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(),
244 ss.as_string());
245 }
246
247 // Check if the ranges are valid
248 if ((((unsigned int)length + (unsigned int)src_pos) >
249 (unsigned int)s->length()) ||
250 (((unsigned int)length + (unsigned int)dst_pos) >
251 (unsigned int)d->length())) {
252 // Pass specific exception reason.
253 ResourceMark rm(THREAD);
254 stringStream ss;
255 if (((unsigned int)length + (unsigned int)src_pos) >
256 (unsigned int)s->length()) {
257 ss.print(
258 "arraycopy: last source index %u out of bounds for object array[%d]",
259 (unsigned int)length + (unsigned int)src_pos, s->length());
260 } else {
261 ss.print("arraycopy: last destination index %u out of bounds for object "
262 "array[%d]",
263 (unsigned int)length + (unsigned int)dst_pos, d->length());
264 }
265 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(),
266 ss.as_string());
267 }
268
269 // Special case. Boundary cases must be checked first
270 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
271 // This is correct, since the position is supposed to be an 'in between
272 // point', i.e., s.length(), points to the right of the last element.
273 if (length == 0) {
274 return;
275 }
276 if (UseCompressedOops) {
277 size_t src_offset =
278 (size_t)refArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
279 size_t dst_offset =
280 (size_t)refArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
281 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, nullptr) ==
282 refArrayOop(s)->obj_at_addr<narrowOop>(src_pos),
283 "sanity");
284 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, nullptr) ==
285 refArrayOop(d)->obj_at_addr<narrowOop>(dst_pos),
286 "sanity");
287 do_copy(s, src_offset, d, dst_offset, length, CHECK);
288 } else {
289 size_t src_offset = (size_t)refArrayOopDesc::obj_at_offset<oop>(src_pos);
290 size_t dst_offset = (size_t)refArrayOopDesc::obj_at_offset<oop>(dst_pos);
291 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, nullptr) ==
292 refArrayOop(s)->obj_at_addr<oop>(src_pos),
293 "sanity");
294 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, nullptr) ==
295 refArrayOop(d)->obj_at_addr<oop>(dst_pos),
296 "sanity");
297 do_copy(s, src_offset, d, dst_offset, length, CHECK);
298 }
299 }
300
301 void RefArrayKlass::initialize(TRAPS) {
302 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
303 }
304
305 void RefArrayKlass::metaspace_pointers_do(MetaspaceClosure *it) {
306 ObjArrayKlass::metaspace_pointers_do(it);
307 }
308
309 // Printing
310
311 void RefArrayKlass::print_on(outputStream* st) const {
312 #ifndef PRODUCT
313 Klass::print_on(st);
314 st->print(" - element klass: ");
315 element_klass()->print_value_on(st);
316 st->cr();
317 #endif // PRODUCT
318 }
319
320 void RefArrayKlass::print_value_on(outputStream* st) const {
321 assert(is_klass(), "must be klass");
322
323 element_klass()->print_value_on(st);
324 st->print("[]");
325 }
326
327 #ifndef PRODUCT
328
329 void RefArrayKlass::oop_print_on(oop obj, outputStream* st) {
330 ArrayKlass::oop_print_on(obj, st);
331 assert(obj->is_refArray(), "must be refArray");
332 refArrayOop oa = refArrayOop(obj);
333 int print_len = MIN2(oa->length(), MaxElementPrintSize);
334 for (int index = 0; index < print_len; index++) {
335 st->print(" - %3d : ", index);
336 if (oa->obj_at(index) != nullptr) {
337 oa->obj_at(index)->print_value_on(st);
338 st->cr();
339 } else {
340 st->print_cr("null");
341 }
342 }
343 int remaining = oa->length() - print_len;
344 if (remaining > 0) {
345 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>",
346 remaining);
347 }
348 }
349
350 #endif // PRODUCT
351
352 void RefArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
353 assert(obj->is_refArray(), "must be refArray");
354 st->print("a ");
355 element_klass()->print_value_on(st);
356 int len = refArrayOop(obj)->length();
357 st->print("[%d] ", len);
358 if (obj != nullptr) {
359 obj->print_address_on(st);
360 } else {
361 st->print_cr("null");
362 }
363 }
364
365 // Verification
366
367 void RefArrayKlass::verify_on(outputStream* st) {
368 ArrayKlass::verify_on(st);
369 guarantee(element_klass()->is_klass(), "should be klass");
370 guarantee(bottom_klass()->is_klass(), "should be klass");
371 Klass *bk = bottom_klass();
372 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(),
373 "invalid bottom klass");
374 }
375
376 void RefArrayKlass::oop_verify_on(oop obj, outputStream* st) {
377 ObjArrayKlass::oop_verify_on(obj, st);
378 guarantee(obj->is_refArray(), "must be refArray");
379
380 refArrayOop oa = refArrayOop(obj);
381 for (int index = 0; index < oa->length(); index++) {
382 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
383 }
384 }