1 /*
2 * Copyright (c) 1997, 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/resourceArea.hpp"
35 #include "memory/universe.hpp"
36 #include "oops/arrayKlass.hpp"
37 #include "oops/instanceKlass.hpp"
38 #include "oops/klass.inline.hpp"
39 #include "oops/objArrayKlass.inline.hpp"
40 #include "oops/objArrayOop.inline.hpp"
41 #include "oops/oop.inline.hpp"
42 #include "oops/symbol.hpp"
43 #include "runtime/handles.inline.hpp"
44 #include "runtime/mutexLocker.hpp"
45 #include "utilities/macros.hpp"
46
47 ObjArrayKlass* ObjArrayKlass::allocate(ClassLoaderData* loader_data, int n, Klass* k, Symbol* name, TRAPS) {
48 assert(ObjArrayKlass::header_size() <= InstanceKlass::header_size(),
49 "array klasses must be same size as InstanceKlass");
50
51 int size = ArrayKlass::static_size(ObjArrayKlass::header_size());
52
53 return new (loader_data, size, THREAD) ObjArrayKlass(n, k, name);
54 }
55
56 ObjArrayKlass* ObjArrayKlass::allocate_objArray_klass(ClassLoaderData* loader_data,
57 int n, Klass* element_klass, TRAPS) {
58
59 // Eagerly allocate the direct array supertype.
60 Klass* super_klass = nullptr;
61 if (!Universe::is_bootstrapping() || vmClasses::Object_klass_loaded()) {
62 assert(MultiArray_lock->holds_lock(THREAD), "must hold lock after bootstrapping");
63 Klass* element_super = element_klass->super();
64 if (element_super != nullptr) {
65 // The element type has a direct super. E.g., String[] has direct super of Object[].
66 // Also, see if the element has secondary supertypes.
67 // We need an array type for each before creating this array type.
68 super_klass = element_super->array_klass(CHECK_NULL);
69 const Array<Klass*>* element_supers = element_klass->secondary_supers();
70 for (int i = element_supers->length() - 1; i >= 0; i--) {
71 Klass* elem_super = element_supers->at(i);
72 elem_super->array_klass(CHECK_NULL);
73 }
74 // Fall through because inheritance is acyclic and we hold the global recursive lock to allocate all the arrays.
75 } else {
76 // The element type is already Object. Object[] has direct super of Object.
77 super_klass = vmClasses::Object_klass();
78 }
79 }
80
81 // Create type name for klass.
82 Symbol* name = nullptr;
83 {
84 ResourceMark rm(THREAD);
85 char *name_str = element_klass->name()->as_C_string();
86 int len = element_klass->name()->utf8_length();
87 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4);
88 int idx = 0;
89 new_str[idx++] = JVM_SIGNATURE_ARRAY;
90 if (element_klass->is_instance_klass()) { // it could be an array or simple type
91 new_str[idx++] = JVM_SIGNATURE_CLASS;
92 }
93 memcpy(&new_str[idx], name_str, len * sizeof(char));
94 idx += len;
95 if (element_klass->is_instance_klass()) {
96 new_str[idx++] = JVM_SIGNATURE_ENDCLASS;
97 }
98 new_str[idx++] = '\0';
99 name = SymbolTable::new_symbol(new_str);
100 }
101
102 // Initialize instance variables
103 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_NULL);
104
105 ModuleEntry* module = oak->module();
106 assert(module != nullptr, "No module entry for array");
107
108 // Call complete_create_array_klass after all instance variables has been initialized.
109 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_NULL);
110
111 // Add all classes to our internal class loader list here,
112 // including classes in the bootstrap (null) class loader.
113 // Do this step after creating the mirror so that if the
114 // mirror creation fails, loaded_classes_do() doesn't find
115 // an array class without a mirror.
116 loader_data->add_class(oak);
117
118 return oak;
119 }
120
121 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name) : ArrayKlass(name, Kind) {
122 set_dimension(n);
123 set_element_klass(element_klass);
124
125 Klass* bk;
126 if (element_klass->is_objArray_klass()) {
127 bk = ObjArrayKlass::cast(element_klass)->bottom_klass();
128 } else {
129 bk = element_klass;
130 }
131 assert(bk != nullptr && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass");
132 set_bottom_klass(bk);
133 set_class_loader_data(bk->class_loader_data());
134
135 if (element_klass->is_array_klass()) {
136 set_lower_dimension(ArrayKlass::cast(element_klass));
137 }
138
139 set_layout_helper(array_layout_helper(T_OBJECT));
140 assert(is_array_klass(), "sanity");
141 assert(is_objArray_klass(), "sanity");
142
143 // Compute modifier flags after bottom_klass and element_klass are initialized.
144 set_modifier_flags(compute_modifier_flags());
145 }
146
147 size_t ObjArrayKlass::oop_size(oop obj, markWord mark) const {
148 // In this assert, we cannot safely access the Klass* with compact headers,
149 // because size_given_klass() calls oop_size() on objects that might be
150 // concurrently forwarded, which would overwrite the Klass*.
151 assert(UseCompactObjectHeaders || obj->is_objArray(), "must be object array");
152 int length = LP64_ONLY(UseCompactObjectHeaders ? mark.array_length() :) objArrayOop(obj)->length();
153 return objArrayOop(obj)->object_size(length);
154 }
155
156 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) {
157 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
158 size_t size = objArrayOopDesc::object_size(length);
159 return (objArrayOop)Universe::heap()->array_allocate(this, size, length,
160 /* do_zero */ true, THREAD);
161 }
162
163 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
164 int length = *sizes;
165 ArrayKlass* ld_klass = lower_dimension();
166 // If length < 0 allocate will throw an exception.
167 objArrayOop array = allocate(length, CHECK_NULL);
168 objArrayHandle h_array (THREAD, array);
169 if (rank > 1) {
170 if (length != 0) {
171 for (int index = 0; index < length; index++) {
172 oop sub_array = ld_klass->multi_allocate(rank - 1, &sizes[1], CHECK_NULL);
173 h_array->obj_at_put(index, sub_array);
174 }
175 } else {
176 // Since this array dimension has zero length, nothing will be
177 // allocated, however the lower dimension values must be checked
178 // for illegal values.
179 for (int i = 0; i < rank - 1; ++i) {
180 sizes += 1;
181 if (*sizes < 0) {
182 THROW_MSG_NULL(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes));
183 }
184 }
185 }
186 }
187 return h_array();
188 }
189
190 // Either oop or narrowOop depending on UseCompressedOops.
191 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset,
192 arrayOop d, size_t dst_offset, int length, TRAPS) {
193 if (s == d) {
194 // since source and destination are equal we do not need conversion checks.
195 assert(length > 0, "sanity check");
196 ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
197 } else {
198 // We have to make sure all elements conform to the destination array
199 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
200 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
201 if (stype == bound || stype->is_subtype_of(bound)) {
202 // elements are guaranteed to be subtypes, so no check necessary
203 ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length);
204 } else {
205 // slow case: need individual subtype checks
206 // note: don't use obj_at_put below because it includes a redundant store check
207 if (!ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length)) {
208 ResourceMark rm(THREAD);
209 stringStream ss;
210 if (!bound->is_subtype_of(stype)) {
211 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
212 stype->external_name(), bound->external_name());
213 } else {
214 // oop_arraycopy should return the index in the source array that
215 // contains the problematic oop.
216 ss.print("arraycopy: element type mismatch: can not cast one of the elements"
217 " of %s[] to the type of the destination array, %s",
218 stype->external_name(), bound->external_name());
219 }
220 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
221 }
222 }
223 }
224 }
225
226 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
227 int dst_pos, int length, TRAPS) {
228 assert(s->is_objArray(), "must be obj array");
229
230 if (!d->is_objArray()) {
231 ResourceMark rm(THREAD);
232 stringStream ss;
233 if (d->is_typeArray()) {
234 ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
235 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
236 } else {
237 ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
238 }
239 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
240 }
241
242 // Check is all offsets and lengths are non negative
243 if (src_pos < 0 || dst_pos < 0 || length < 0) {
244 // Pass specific exception reason.
245 ResourceMark rm(THREAD);
246 stringStream ss;
247 if (src_pos < 0) {
248 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
249 src_pos, s->length());
250 } else if (dst_pos < 0) {
251 ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
252 dst_pos, d->length());
253 } else {
254 ss.print("arraycopy: length %d is negative", length);
255 }
256 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
257 }
258 // Check if the ranges are valid
259 if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
260 (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
261 // Pass specific exception reason.
262 ResourceMark rm(THREAD);
263 stringStream ss;
264 if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
265 ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
266 (unsigned int) length + (unsigned int) src_pos, s->length());
267 } else {
268 ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
269 (unsigned int) length + (unsigned int) dst_pos, d->length());
270 }
271 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
272 }
273
274 // Special case. Boundary cases must be checked first
275 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
276 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
277 // points to the right of the last element.
278 if (length==0) {
279 return;
280 }
281 if (UseCompressedOops) {
282 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
283 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
284 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, nullptr) ==
285 objArrayOop(s)->obj_at_addr<narrowOop>(src_pos), "sanity");
286 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, nullptr) ==
287 objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos), "sanity");
288 do_copy(s, src_offset, d, dst_offset, length, CHECK);
289 } else {
290 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
291 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
292 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, nullptr) ==
293 objArrayOop(s)->obj_at_addr<oop>(src_pos), "sanity");
294 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, nullptr) ==
295 objArrayOop(d)->obj_at_addr<oop>(dst_pos), "sanity");
296 do_copy(s, src_offset, d, dst_offset, length, CHECK);
297 }
298 }
299
300 bool ObjArrayKlass::can_be_primary_super_slow() const {
301 if (!bottom_klass()->can_be_primary_super())
302 // array of interfaces
303 return false;
304 else
305 return Klass::can_be_primary_super_slow();
306 }
307
308 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots,
309 Array<InstanceKlass*>* transitive_interfaces) {
310 assert(transitive_interfaces == nullptr, "sanity");
311 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
312 const Array<Klass*>* elem_supers = element_klass()->secondary_supers();
313 int num_elem_supers = elem_supers == nullptr ? 0 : elem_supers->length();
314 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
315 if (num_secondaries == 2) {
316 // Must share this for correct bootstrapping!
317 set_secondary_supers(Universe::the_array_interfaces_array(),
318 Universe::the_array_interfaces_bitmap());
319 return nullptr;
320 } else {
321 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
322 secondaries->push(vmClasses::Cloneable_klass());
323 secondaries->push(vmClasses::Serializable_klass());
324 for (int i = 0; i < num_elem_supers; i++) {
325 Klass* elem_super = elem_supers->at(i);
326 Klass* array_super = elem_super->array_klass_or_null();
327 assert(array_super != nullptr, "must already have been created");
328 secondaries->push(array_super);
329 }
330 return secondaries;
331 }
332 }
333
334 void ObjArrayKlass::initialize(TRAPS) {
335 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
336 }
337
338 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
339 ArrayKlass::metaspace_pointers_do(it);
340 it->push(&_element_klass);
341 it->push(&_bottom_klass);
342 }
343
344 u2 ObjArrayKlass::compute_modifier_flags() const {
345 // The modifier for an objectArray is the same as its element
346 assert (element_klass() != nullptr, "should be initialized");
347
348 // Return the flags of the bottom element type.
349 u2 element_flags = bottom_klass()->compute_modifier_flags();
350
351 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
352 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
353 }
354
355 ModuleEntry* ObjArrayKlass::module() const {
356 assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
357 // The array is defined in the module of its bottom class
358 return bottom_klass()->module();
359 }
360
361 PackageEntry* ObjArrayKlass::package() const {
362 assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
363 return bottom_klass()->package();
364 }
365
366 // Printing
367
368 void ObjArrayKlass::print_on(outputStream* st) const {
369 #ifndef PRODUCT
370 Klass::print_on(st);
371 st->print(" - instance klass: ");
372 element_klass()->print_value_on(st);
373 st->cr();
374 #endif //PRODUCT
375 }
376
377 void ObjArrayKlass::print_value_on(outputStream* st) const {
378 assert(is_klass(), "must be klass");
379
380 element_klass()->print_value_on(st);
381 st->print("[]");
382 }
383
384 #ifndef PRODUCT
385
386 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
387 ArrayKlass::oop_print_on(obj, st);
388 assert(obj->is_objArray(), "must be objArray");
389 objArrayOop oa = objArrayOop(obj);
390 int print_len = MIN2(oa->length(), MaxElementPrintSize);
391 for(int index = 0; index < print_len; index++) {
392 st->print(" - %3d : ", index);
393 if (oa->obj_at(index) != nullptr) {
394 oa->obj_at(index)->print_value_on(st);
395 st->cr();
396 } else {
397 st->print_cr("null");
398 }
399 }
400 int remaining = oa->length() - print_len;
401 if (remaining > 0) {
402 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
403 }
404 }
405
406 #endif //PRODUCT
407
408 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
409 assert(obj->is_objArray(), "must be objArray");
410 st->print("a ");
411 element_klass()->print_value_on(st);
412 int len = objArrayOop(obj)->length();
413 st->print("[%d] ", len);
414 if (obj != nullptr) {
415 obj->print_address_on(st);
416 } else {
417 st->print_cr("null");
418 }
419 }
420
421 const char* ObjArrayKlass::internal_name() const {
422 return external_name();
423 }
424
425
426 // Verification
427
428 void ObjArrayKlass::verify_on(outputStream* st) {
429 ArrayKlass::verify_on(st);
430 guarantee(element_klass()->is_klass(), "should be klass");
431 guarantee(bottom_klass()->is_klass(), "should be klass");
432 Klass* bk = bottom_klass();
433 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(), "invalid bottom klass");
434 }
435
436 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
437 ArrayKlass::oop_verify_on(obj, st);
438 guarantee(obj->is_objArray(), "must be objArray");
439 objArrayOop oa = objArrayOop(obj);
440 for(int index = 0; index < oa->length(); index++) {
441 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
442 }
443 }