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 super_klass = element_klass->array_klass(CHECK_NULL);
74 }
75
76 // Create type name for klass.
77 Symbol* name = create_element_klass_array_name(THREAD, element_klass);
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 have 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 ArrayProperties props)
102 : ObjArrayKlass(n, element_klass, name, Kind, props) {
103 assert(is_refArray_klass(), "sanity");
104 }
105
106 size_t RefArrayKlass::oop_size(oop obj) const {
107 // In this assert, we cannot safely access the Klass* with compact headers,
108 // because size_given_klass() calls oop_size() on objects that might be
109 // concurrently forwarded, which would overwrite the Klass*.
110 assert(UseCompactObjectHeaders || obj->is_refArray(), "must be a reference array");
111 return refArrayOop(obj)->object_size();
112 }
113
114 refArrayOop RefArrayKlass::allocate_instance(int length, TRAPS) {
115 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
116 size_t size = refArrayOopDesc::object_size(length);
117 oop array = Universe::heap()->array_allocate(
118 this, size, length, /* do_zero */ true, CHECK_NULL);
119 return oop_cast<refArrayOop>(array);
120 }
121
122 static void throw_array_null_pointer_store_exception(arrayOop src, arrayOop dst, TRAPS) {
123 ResourceMark rm(THREAD);
124 Klass* bound = ObjArrayKlass::cast(dst->klass())->element_klass();
125 stringStream ss;
126 ss.print("arraycopy: can not copy null values into %s[]",
127 bound->external_name());
128 THROW_MSG(vmSymbols::java_lang_NullPointerException(), ss.as_string());
129 }
130
131 static void throw_array_store_exception(arrayOop src, arrayOop dst, TRAPS) {
132 ResourceMark rm(THREAD);
133 Klass* bound = ObjArrayKlass::cast(dst->klass())->element_klass();
134 Klass* stype = ObjArrayKlass::cast(src->klass())->element_klass();
135 stringStream ss;
136 if (!bound->is_subtype_of(stype)) {
137 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
138 stype->external_name(), bound->external_name());
139 } else {
140 // oop_arraycopy should return the index in the source array that
141 // contains the problematic oop.
142 ss.print("arraycopy: element type mismatch: can not cast one of the elements"
143 " of %s[] to the type of the destination array, %s",
144 stype->external_name(), bound->external_name());
145 }
146 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
147 }
148
149 // Either oop or narrowOop depending on UseCompressedOops.
150 void RefArrayKlass::do_copy(arrayOop s, size_t src_offset, arrayOop d,
151 size_t dst_offset, int length, TRAPS) {
152 if (s == d) {
153 // since source and destination are equal we do not need conversion checks.
154 assert(length > 0, "sanity check");
155 OopCopyResult result = ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
156 assert(result == OopCopyResult::ok, "Should never fail");
157 } else {
158 // Perform null check if dst is null-free but src has no such guarantee
159 bool null_check = ((!s->klass()->is_null_free_array_klass()) &&
160 d->klass()->is_null_free_array_klass());
161 // We have to make sure all elements conform to the destination array
162 Klass *bound = RefArrayKlass::cast(d->klass())->element_klass();
163 Klass *stype = RefArrayKlass::cast(s->klass())->element_klass();
164 bool type_check = stype != bound && !stype->is_subtype_of(bound);
165
166 auto arraycopy = [&] {
167 if (type_check) {
168 if (null_check) {
169 return ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST | ARRAYCOPY_NOTNULL>::
170 oop_arraycopy(s, src_offset, d, dst_offset, length);
171 } else {
172 return ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::
173 oop_arraycopy(s, src_offset, d, dst_offset, length);
174 }
175 } else {
176 if (null_check) {
177 return ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_NOTNULL>::
178 oop_arraycopy(s, src_offset, d, dst_offset, length);
179 } else {
180 return ArrayAccess<ARRAYCOPY_DISJOINT>::
181 oop_arraycopy(s, src_offset, d, dst_offset, length);
182 }
183 }
184 };
185
186 OopCopyResult result = arraycopy();
187
188 switch (result) {
189 case OopCopyResult::ok:
190 // Done
191 break;
192 case OopCopyResult::failed_check_class_cast:
193 throw_array_store_exception(s, d, JavaThread::current());
194 break;
195 case OopCopyResult::failed_check_null:
196 throw_array_null_pointer_store_exception(s, d, JavaThread::current());
197 break;
198 default:
199 ShouldNotReachHere();
200 }
201 }
202 }
203
204 void RefArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos,
205 int length, TRAPS) {
206 assert(s->is_refArray(), "must be a reference array");
207
208 if (UseArrayFlattening && d->is_flatArray()) {
209 FlatArrayKlass::cast(d->klass())->copy_array(s, src_pos, d, dst_pos, length, THREAD);
210 return;
211 }
212
213 if (!d->is_refArray()) {
214 ResourceMark rm(THREAD);
215 stringStream ss;
216 if (d->is_typeArray()) {
217 ss.print(
218 "arraycopy: type mismatch: can not copy object array[] into %s[]",
219 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
220 } else {
221 ss.print("arraycopy: destination type %s is not an array",
222 d->klass()->external_name());
223 }
224 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
225 }
226
227 // Check if all offsets and lengths are non negative
228 if (src_pos < 0 || dst_pos < 0 || length < 0) {
229 // Pass specific exception reason.
230 ResourceMark rm(THREAD);
231 stringStream ss;
232 if (src_pos < 0) {
233 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
234 src_pos, s->length());
235 } else if (dst_pos < 0) {
236 ss.print(
237 "arraycopy: destination index %d out of bounds for object array[%d]",
238 dst_pos, d->length());
239 } else {
240 ss.print("arraycopy: length %d is negative", length);
241 }
242 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(),
243 ss.as_string());
244 }
245
246 // Check if the ranges are valid
247 if ((((unsigned int)length + (unsigned int)src_pos) >
248 (unsigned int)s->length()) ||
249 (((unsigned int)length + (unsigned int)dst_pos) >
250 (unsigned int)d->length())) {
251 // Pass specific exception reason.
252 ResourceMark rm(THREAD);
253 stringStream ss;
254 if (((unsigned int)length + (unsigned int)src_pos) >
255 (unsigned int)s->length()) {
256 ss.print(
257 "arraycopy: last source index %u out of bounds for object array[%d]",
258 (unsigned int)length + (unsigned int)src_pos, s->length());
259 } else {
260 ss.print("arraycopy: last destination index %u out of bounds for object "
261 "array[%d]",
262 (unsigned int)length + (unsigned int)dst_pos, d->length());
263 }
264 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(),
265 ss.as_string());
266 }
267
268 // Special case. Boundary cases must be checked first
269 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
270 // This is correct, since the position is supposed to be an 'in between
271 // point', i.e., s.length(), points to the right of the last element.
272 if (length == 0) {
273 return;
274 }
275 if (UseCompressedOops) {
276 size_t src_offset =
277 (size_t)refArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
278 size_t dst_offset =
279 (size_t)refArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
280 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, nullptr) ==
281 refArrayOop(s)->obj_at_addr<narrowOop>(src_pos),
282 "sanity");
283 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, nullptr) ==
284 refArrayOop(d)->obj_at_addr<narrowOop>(dst_pos),
285 "sanity");
286 do_copy(s, src_offset, d, dst_offset, length, CHECK);
287 } else {
288 size_t src_offset = (size_t)refArrayOopDesc::obj_at_offset<oop>(src_pos);
289 size_t dst_offset = (size_t)refArrayOopDesc::obj_at_offset<oop>(dst_pos);
290 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, nullptr) ==
291 refArrayOop(s)->obj_at_addr<oop>(src_pos),
292 "sanity");
293 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, nullptr) ==
294 refArrayOop(d)->obj_at_addr<oop>(dst_pos),
295 "sanity");
296 do_copy(s, src_offset, d, dst_offset, length, CHECK);
297 }
298 }
299
300 void RefArrayKlass::initialize(TRAPS) {
301 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
302 }
303
304 void RefArrayKlass::metaspace_pointers_do(MetaspaceClosure *it) {
305 ObjArrayKlass::metaspace_pointers_do(it);
306 }
307
308 // Printing
309
310 void RefArrayKlass::print_on(outputStream* st) const {
311 #ifndef PRODUCT
312 Klass::print_on(st);
313 st->print(" - element klass: ");
314 element_klass()->print_value_on(st);
315 st->cr();
316 #endif // PRODUCT
317 }
318
319 void RefArrayKlass::print_value_on(outputStream* st) const {
320 assert(is_klass(), "must be klass");
321
322 element_klass()->print_value_on(st);
323 st->print("[]");
324 }
325
326 #ifndef PRODUCT
327
328 void RefArrayKlass::oop_print_on(oop obj, outputStream* st) {
329 ArrayKlass::oop_print_on(obj, st);
330 assert(obj->is_refArray(), "must be refArray");
331 refArrayOop oa = refArrayOop(obj);
332 int print_len = MIN2(oa->length(), MaxElementPrintSize);
333 for (int index = 0; index < print_len; index++) {
334 st->print(" - %3d : ", index);
335 if (oa->obj_at(index) != nullptr) {
336 oa->obj_at(index)->print_value_on(st);
337 st->cr();
338 } else {
339 st->print_cr("null");
340 }
341 }
342 int remaining = oa->length() - print_len;
343 if (remaining > 0) {
344 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>",
345 remaining);
346 }
347 }
348
349 #endif // PRODUCT
350
351 void RefArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
352 assert(obj->is_refArray(), "must be refArray");
353 st->print("a ");
354 element_klass()->print_value_on(st);
355 int len = refArrayOop(obj)->length();
356 st->print("[%d] ", len);
357 if (obj != nullptr) {
358 obj->print_address_on(st);
359 } else {
360 st->print_cr("null");
361 }
362 }
363
364 // Verification
365
366 void RefArrayKlass::verify_on(outputStream* st) {
367 ArrayKlass::verify_on(st);
368 guarantee(element_klass()->is_klass(), "should be klass");
369 guarantee(bottom_klass()->is_klass(), "should be klass");
370 Klass *bk = bottom_klass();
371 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(),
372 "invalid bottom klass");
373 }
374
375 void RefArrayKlass::oop_verify_on(oop obj, outputStream* st) {
376 ObjArrayKlass::oop_verify_on(obj, st);
377 guarantee(obj->is_refArray(), "must be refArray");
378
379 refArrayOop oa = refArrayOop(obj);
380 for (int index = 0; index < oa->length(); index++) {
381 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
382 }
383 }