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