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/refArrayKlass.inline.hpp"
44 #include "oops/refArrayOop.inline.hpp"
45 #include "oops/symbol.hpp"
46 #include "runtime/handles.inline.hpp"
47 #include "runtime/mutexLocker.hpp"
48 #include "utilities/macros.hpp"
49
50 RefArrayKlass *RefArrayKlass::allocate_klass(ClassLoaderData* loader_data, int n,
51 Klass* k, Symbol *name, ArrayKlass::ArrayProperties props,
52 TRAPS) {
53 assert(RefArrayKlass::header_size() <= InstanceKlass::header_size(),
54 "array klasses must be same size as InstanceKlass");
55
56 int size = ArrayKlass::static_size(RefArrayKlass::header_size());
57
58 return new (loader_data, size, THREAD) RefArrayKlass(n, k, name, props);
59 }
60
61 RefArrayKlass* RefArrayKlass::allocate_refArray_klass(ClassLoaderData* loader_data, int n,
62 Klass* element_klass, ArrayKlass::ArrayProperties props,
63 TRAPS) {
64 assert(!ArrayKlass::is_null_restricted(props) || (n == 1 && element_klass->is_inline_klass()),
65 "null-free unsupported");
66
67 // Eagerly allocate the direct array supertype.
68 Klass* super_klass = nullptr;
69 if (!Universe::is_bootstrapping() || vmClasses::Object_klass_is_loaded()) {
70 assert(MultiArray_lock->holds_lock(THREAD),
71 "must hold lock after bootstrapping");
72 Klass* element_super = element_klass->super();
73 super_klass = element_klass->array_klass(CHECK_NULL);
74 }
75
76 // Create type name for klass.
77 Symbol* name = ArrayKlass::create_element_klass_array_name(element_klass, CHECK_NULL);
78
79 // Initialize instance variables
80 RefArrayKlass* oak = RefArrayKlass::allocate_klass(loader_data, n, element_klass,
81 name, props, CHECK_NULL);
82
83 ModuleEntry* module = oak->module();
84 assert(module != nullptr, "No module entry for array");
85
86 // Call complete_create_array_klass after all instance variables has been
87 // initialized.
88 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_NULL);
89
90 // Add all classes to our internal class loader list here,
91 // including classes in the bootstrap (null) class loader.
92 // Do this step after creating the mirror so that if the
93 // mirror creation fails, loaded_classes_do() doesn't find
94 // an array class without a mirror.
95 loader_data->add_class(oak);
96
97 return oak;
98 }
99
100 RefArrayKlass::RefArrayKlass(int n, Klass* element_klass, Symbol* name,
101 ArrayKlass::ArrayProperties props)
102 : ObjArrayKlass(n, element_klass, name, Kind, props,
103 ArrayKlass::is_null_restricted(props) ? markWord::null_free_array_prototype() : markWord::prototype()) {
104 set_dimension(n);
105 set_element_klass(element_klass);
106
107 Klass* bk;
108 if (element_klass->is_objArray_klass()) {
109 bk = ObjArrayKlass::cast(element_klass)->bottom_klass();
110 } else {
111 bk = element_klass;
112 }
113 assert(bk != nullptr && (bk->is_instance_klass() || bk->is_typeArray_klass()),
114 "invalid bottom klass");
115 set_bottom_klass(bk);
116 set_class_loader_data(bk->class_loader_data());
117
118 if (element_klass->is_array_klass()) {
119 set_lower_dimension(ArrayKlass::cast(element_klass));
120 }
121
122 int lh = array_layout_helper(T_OBJECT);
123 if (ArrayKlass::is_null_restricted(props)) {
124 assert(n == 1, "Bytecode does not support null-free multi-dim");
125 lh = layout_helper_set_null_free(lh);
126 #ifdef _LP64
127 assert(prototype_header().is_null_free_array(), "sanity");
128 #endif
129 }
130 set_layout_helper(lh);
131 assert(is_array_klass(), "sanity");
132 assert(is_refArray_klass(), "sanity");
133 }
134
135 size_t RefArrayKlass::oop_size(oop obj) const {
136 // In this assert, we cannot safely access the Klass* with compact headers,
137 // because size_given_klass() calls oop_size() on objects that might be
138 // concurrently forwarded, which would overwrite the Klass*.
139 assert(UseCompactObjectHeaders || obj->is_refArray(), "must be a reference array");
140 return refArrayOop(obj)->object_size();
141 }
142
143 objArrayOop RefArrayKlass::allocate_instance(int length, ArrayProperties props, TRAPS) {
144 check_array_allocation_length(
145 length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
146 size_t size = refArrayOopDesc::object_size(length);
147 objArrayOop array = (objArrayOop)Universe::heap()->array_allocate(
148 this, size, length,
149 /* do_zero */ true, CHECK_NULL);
150 assert(array->is_refArray(), "Must be");
151 return array;
152 }
153
154 static void throw_array_null_pointer_store_exception(arrayOop src, arrayOop dst, TRAPS) {
155 ResourceMark rm(THREAD);
156 Klass* bound = ObjArrayKlass::cast(dst->klass())->element_klass();
157 stringStream ss;
158 ss.print("arraycopy: can not copy null values into %s[]",
159 bound->external_name());
160 THROW_MSG(vmSymbols::java_lang_NullPointerException(), ss.as_string());
161 }
162
163 static void throw_array_store_exception(arrayOop src, arrayOop dst, TRAPS) {
164 ResourceMark rm(THREAD);
165 Klass* bound = ObjArrayKlass::cast(dst->klass())->element_klass();
166 Klass* stype = ObjArrayKlass::cast(src->klass())->element_klass();
167 stringStream ss;
168 if (!bound->is_subtype_of(stype)) {
169 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
170 stype->external_name(), bound->external_name());
171 } else {
172 // oop_arraycopy should return the index in the source array that
173 // contains the problematic oop.
174 ss.print("arraycopy: element type mismatch: can not cast one of the elements"
175 " of %s[] to the type of the destination array, %s",
176 stype->external_name(), bound->external_name());
177 }
178 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
179 }
180
181
182 // Either oop or narrowOop depending on UseCompressedOops.
183 void RefArrayKlass::do_copy(arrayOop s, size_t src_offset, arrayOop d,
184 size_t dst_offset, int length, TRAPS) {
185 if (s == d) {
186 // since source and destination are equal we do not need conversion checks.
187 assert(length > 0, "sanity check");
188 OopCopyResult result = ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
189 assert(result == OopCopyResult::ok, "Should never fail");
190 } else {
191 // Perform null check if dst is null-free but src has no such guarantee
192 bool null_check = ((!s->klass()->is_null_free_array_klass()) &&
193 d->klass()->is_null_free_array_klass());
194 // We have to make sure all elements conform to the destination array
195 Klass *bound = RefArrayKlass::cast(d->klass())->element_klass();
196 Klass *stype = RefArrayKlass::cast(s->klass())->element_klass();
197 bool type_check = stype != bound && !stype->is_subtype_of(bound);
198
199 auto arraycopy = [&] {
200 if (type_check) {
201 if (null_check) {
202 return ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST | ARRAYCOPY_NOTNULL>::
203 oop_arraycopy(s, src_offset, d, dst_offset, length);
204 } else {
205 return ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::
206 oop_arraycopy(s, src_offset, d, dst_offset, length);
207 }
208 } else {
209 if (null_check) {
210 return ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_NOTNULL>::
211 oop_arraycopy(s, src_offset, d, dst_offset, length);
212 } else {
213 return ArrayAccess<ARRAYCOPY_DISJOINT>::
214 oop_arraycopy(s, src_offset, d, dst_offset, length);
215 }
216 }
217 };
218
219 OopCopyResult result = arraycopy();
220
221 switch (result) {
222 case OopCopyResult::ok:
223 // Done
224 break;
225 case OopCopyResult::failed_check_class_cast:
226 throw_array_store_exception(s, d, JavaThread::current());
227 break;
228 case OopCopyResult::failed_check_null:
229 throw_array_null_pointer_store_exception(s, d, JavaThread::current());
230 break;
231 default:
232 ShouldNotReachHere();
233 }
234 }
235 }
236
237 void RefArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos,
238 int length, TRAPS) {
239 assert(s->is_refArray(), "must be a reference array");
240
241 if (UseArrayFlattening) {
242 if (d->is_flatArray()) {
243 FlatArrayKlass::cast(d->klass())->copy_array(s, src_pos, d, dst_pos, length, THREAD);
244 return;
245 }
246 if (s->is_flatArray()) {
247 FlatArrayKlass::cast(s->klass())->copy_array(s, src_pos, d, dst_pos, length, THREAD);
248 return;
249 }
250 }
251
252 if (!d->is_refArray()) {
253 ResourceMark rm(THREAD);
254 stringStream ss;
255 if (d->is_typeArray()) {
256 ss.print(
257 "arraycopy: type mismatch: can not copy object array[] into %s[]",
258 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
259 } else {
260 ss.print("arraycopy: destination type %s is not an array",
261 d->klass()->external_name());
262 }
263 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
264 }
265
266 // Check is all offsets and lengths are non negative
267 if (src_pos < 0 || dst_pos < 0 || length < 0) {
268 // Pass specific exception reason.
269 ResourceMark rm(THREAD);
270 stringStream ss;
271 if (src_pos < 0) {
272 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
273 src_pos, s->length());
274 } else if (dst_pos < 0) {
275 ss.print(
276 "arraycopy: destination index %d out of bounds for object array[%d]",
277 dst_pos, d->length());
278 } else {
279 ss.print("arraycopy: length %d is negative", length);
280 }
281 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(),
282 ss.as_string());
283 }
284 // Check if the ranges are valid
285 if ((((unsigned int)length + (unsigned int)src_pos) >
286 (unsigned int)s->length()) ||
287 (((unsigned int)length + (unsigned int)dst_pos) >
288 (unsigned int)d->length())) {
289 // Pass specific exception reason.
290 ResourceMark rm(THREAD);
291 stringStream ss;
292 if (((unsigned int)length + (unsigned int)src_pos) >
293 (unsigned int)s->length()) {
294 ss.print(
295 "arraycopy: last source index %u out of bounds for object array[%d]",
296 (unsigned int)length + (unsigned int)src_pos, s->length());
297 } else {
298 ss.print("arraycopy: last destination index %u out of bounds for object "
299 "array[%d]",
300 (unsigned int)length + (unsigned int)dst_pos, d->length());
301 }
302 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(),
303 ss.as_string());
304 }
305
306 // Special case. Boundary cases must be checked first
307 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
308 // This is correct, since the position is supposed to be an 'in between
309 // point', i.e., s.length(), points to the right of the last element.
310 if (length == 0) {
311 return;
312 }
313 if (UseCompressedOops) {
314 size_t src_offset =
315 (size_t)refArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
316 size_t dst_offset =
317 (size_t)refArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
318 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, nullptr) ==
319 refArrayOop(s)->obj_at_addr<narrowOop>(src_pos),
320 "sanity");
321 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, nullptr) ==
322 refArrayOop(d)->obj_at_addr<narrowOop>(dst_pos),
323 "sanity");
324 do_copy(s, src_offset, d, dst_offset, length, CHECK);
325 } else {
326 size_t src_offset = (size_t)refArrayOopDesc::obj_at_offset<oop>(src_pos);
327 size_t dst_offset = (size_t)refArrayOopDesc::obj_at_offset<oop>(dst_pos);
328 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, nullptr) ==
329 refArrayOop(s)->obj_at_addr<oop>(src_pos),
330 "sanity");
331 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, nullptr) ==
332 refArrayOop(d)->obj_at_addr<oop>(dst_pos),
333 "sanity");
334 do_copy(s, src_offset, d, dst_offset, length, CHECK);
335 }
336 }
337
338 void RefArrayKlass::initialize(TRAPS) {
339 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
340 }
341
342 void RefArrayKlass::metaspace_pointers_do(MetaspaceClosure *it) {
343 ObjArrayKlass::metaspace_pointers_do(it);
344 }
345
346 // Printing
347
348 void RefArrayKlass::print_on(outputStream* st) const {
349 #ifndef PRODUCT
350 Klass::print_on(st);
351 st->print(" - element klass: ");
352 element_klass()->print_value_on(st);
353 st->cr();
354 #endif // PRODUCT
355 }
356
357 void RefArrayKlass::print_value_on(outputStream* st) const {
358 assert(is_klass(), "must be klass");
359
360 element_klass()->print_value_on(st);
361 st->print("[]");
362 }
363
364 #ifndef PRODUCT
365
366 void RefArrayKlass::oop_print_on(oop obj, outputStream* st) {
367 ArrayKlass::oop_print_on(obj, st);
368 assert(obj->is_refArray(), "must be refArray");
369 refArrayOop oa = refArrayOop(obj);
370 int print_len = MIN2(oa->length(), MaxElementPrintSize);
371 for (int index = 0; index < print_len; index++) {
372 st->print(" - %3d : ", index);
373 if (oa->obj_at(index) != nullptr) {
374 oa->obj_at(index)->print_value_on(st);
375 st->cr();
376 } else {
377 st->print_cr("null");
378 }
379 }
380 int remaining = oa->length() - print_len;
381 if (remaining > 0) {
382 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>",
383 remaining);
384 }
385 }
386
387 #endif // PRODUCT
388
389 void RefArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
390 assert(obj->is_refArray(), "must be refArray");
391 st->print("a ");
392 element_klass()->print_value_on(st);
393 int len = refArrayOop(obj)->length();
394 st->print("[%d] ", len);
395 if (obj != nullptr) {
396 obj->print_address_on(st);
397 } else {
398 st->print_cr("null");
399 }
400 }
401
402 // Verification
403
404 void RefArrayKlass::verify_on(outputStream* st) {
405 ArrayKlass::verify_on(st);
406 guarantee(element_klass()->is_klass(), "should be klass");
407 guarantee(bottom_klass()->is_klass(), "should be klass");
408 Klass *bk = bottom_klass();
409 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass() ||
410 bk->is_flatArray_klass(),
411 "invalid bottom klass");
412 }
413
414 void RefArrayKlass::oop_verify_on(oop obj, outputStream* st) {
415 ArrayKlass::oop_verify_on(obj, st);
416 guarantee(obj->is_refArray(), "must be refArray");
417 guarantee(obj->is_null_free_array() || (!is_null_free_array_klass()),
418 "null-free klass but not object");
419 refArrayOop oa = refArrayOop(obj);
420 for (int index = 0; index < oa->length(); index++) {
421 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
422 }
423 }