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 "precompiled.hpp"
26 #include "classfile/moduleEntry.hpp"
27 #include "classfile/packageEntry.hpp"
28 #include "classfile/symbolTable.hpp"
29 #include "classfile/vmClasses.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "gc/shared/collectedHeap.inline.hpp"
32 #include "memory/iterator.inline.hpp"
33 #include "memory/metadataFactory.hpp"
34 #include "memory/metaspaceClosure.hpp"
35 #include "memory/oopFactory.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "memory/universe.hpp"
38 #include "oops/arrayKlass.hpp"
39 #include "oops/instanceKlass.hpp"
40 #include "oops/klass.inline.hpp"
41 #include "oops/objArrayKlass.inline.hpp"
42 #include "oops/objArrayOop.inline.hpp"
43 #include "oops/oop.inline.hpp"
44 #include "oops/symbol.hpp"
45 #include "runtime/handles.inline.hpp"
46 #include "runtime/mutexLocker.hpp"
47 #include "utilities/macros.hpp"
48
49 ObjArrayKlass* ObjArrayKlass::allocate(ClassLoaderData* loader_data, int n,
50 Klass* k, Symbol* name, bool null_free,
51 TRAPS) {
52 assert(ObjArrayKlass::header_size() <= InstanceKlass::header_size(),
53 "array klasses must be same size as InstanceKlass");
54
55 int size = ArrayKlass::static_size(ObjArrayKlass::header_size());
56
57 return new (loader_data, size, THREAD) ObjArrayKlass(n, k, name, null_free);
58 }
59
60 ObjArrayKlass* ObjArrayKlass::allocate_objArray_klass(ClassLoaderData* loader_data,
61 int n, Klass* element_klass,
62 bool null_free, TRAPS) {
63 assert(!null_free || (n == 1 && element_klass->is_inline_klass()), "null-free unsupported");
64
65 // Eagerly allocate the direct array supertype.
66 Klass* super_klass = nullptr;
67 if (!Universe::is_bootstrapping() || vmClasses::Object_klass_loaded()) {
68 assert(MultiArray_lock->holds_lock(THREAD), "must hold lock after bootstrapping");
69 Klass* element_super = element_klass->super();
70 if (element_super != nullptr) {
71 // The element type has a direct super. E.g., String[] has direct super of Object[].
72 // Also, see if the element has secondary supertypes.
73 // We need an array type for each before creating this array type.
74 if (null_free) {
75 super_klass = element_klass->array_klass(CHECK_NULL);
76 } else {
77 super_klass = element_super->array_klass(CHECK_NULL);
78 }
79 const Array<Klass*>* element_supers = element_klass->secondary_supers();
80 for (int i = element_supers->length() - 1; i >= 0; i--) {
81 Klass* elem_super = element_supers->at(i);
82 elem_super->array_klass(CHECK_NULL);
83 }
84 // Fall through because inheritance is acyclic and we hold the global recursive lock to allocate all the arrays.
85 } else {
86 // The element type is already Object. Object[] has direct super of Object.
87 super_klass = vmClasses::Object_klass();
88 }
89 }
90
91 // Create type name for klass.
92 Symbol* name = ArrayKlass::create_element_klass_array_name(element_klass, CHECK_NULL);
93
94 // Initialize instance variables
95 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, null_free, CHECK_NULL);
96
97 ModuleEntry* module = oak->module();
98 assert(module != nullptr, "No module entry for array");
99
100 // Call complete_create_array_klass after all instance variables has been initialized.
101 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_NULL);
102
103 // Add all classes to our internal class loader list here,
104 // including classes in the bootstrap (null) class loader.
105 // Do this step after creating the mirror so that if the
106 // mirror creation fails, loaded_classes_do() doesn't find
107 // an array class without a mirror.
108 loader_data->add_class(oak);
109
110 return oak;
111 }
112
113 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name, bool null_free) : ArrayKlass(name, Kind) {
114 set_dimension(n);
115 set_element_klass(element_klass);
116
117 Klass* bk;
118 if (element_klass->is_objArray_klass()) {
119 bk = ObjArrayKlass::cast(element_klass)->bottom_klass();
120 } else if (element_klass->is_flatArray_klass()) {
121 bk = FlatArrayKlass::cast(element_klass)->element_klass();
122 } else {
123 bk = element_klass;
124 }
125 assert(bk != nullptr && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass");
126 set_bottom_klass(bk);
127 set_class_loader_data(bk->class_loader_data());
128
129 if (element_klass->is_array_klass()) {
130 set_lower_dimension(ArrayKlass::cast(element_klass));
131 }
132
133 int lh = array_layout_helper(T_OBJECT);
134 if (null_free) {
135 assert(n == 1, "Bytecode does not support null-free multi-dim");
136 lh = layout_helper_set_null_free(lh);
137 #ifdef _LP64
138 set_prototype_header(markWord::null_free_array_prototype());
139 assert(prototype_header().is_null_free_array(), "sanity");
140 #else
141 set_prototype_header(markWord::inline_type_prototype());
142 #endif
143 }
144 set_layout_helper(lh);
145 assert(is_array_klass(), "sanity");
146 assert(is_objArray_klass(), "sanity");
147 }
148
149 size_t ObjArrayKlass::oop_size(oop obj) const {
150 assert(obj->is_objArray(), "must be object array");
151 return objArrayOop(obj)->object_size();
152 }
153
154 objArrayOop ObjArrayKlass::allocate(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 bool populate_null_free = is_null_free_array_klass();
158 objArrayOop array = (objArrayOop)Universe::heap()->array_allocate(this, size, length,
159 /* do_zero */ true, CHECK_NULL);
160 objArrayHandle array_h(THREAD, array);
161 if (populate_null_free) {
162 assert(dimension() == 1, "Can only populate the final dimension");
163 assert(element_klass()->is_inline_klass(), "Unexpected");
164 assert(!element_klass()->is_array_klass(), "ArrayKlass unexpected here");
165 element_klass()->initialize(CHECK_NULL);
166 // Populate default values...
167 instanceOop value = (instanceOop) InlineKlass::cast(element_klass())->default_value();
168 for (int i = 0; i < length; i++) {
169 array_h->obj_at_put(i, value);
170 }
171 }
172 return array_h();
173 }
174
175 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
176 int length = *sizes;
177 ArrayKlass* ld_klass = lower_dimension();
178 // If length < 0 allocate will throw an exception.
179 objArrayOop array = allocate(length, CHECK_NULL);
180 objArrayHandle h_array (THREAD, array);
181 if (rank > 1) {
182 if (length != 0) {
183 for (int index = 0; index < length; index++) {
184 oop sub_array = ld_klass->multi_allocate(rank-1, &sizes[1], CHECK_NULL);
185 h_array->obj_at_put(index, sub_array);
186 }
187 } else {
188 // Since this array dimension has zero length, nothing will be
189 // allocated, however the lower dimension values must be checked
190 // for illegal values.
191 for (int i = 0; i < rank - 1; ++i) {
192 sizes += 1;
193 if (*sizes < 0) {
194 THROW_MSG_NULL(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes));
195 }
196 }
197 }
198 }
199 return h_array();
200 }
201
202 // Either oop or narrowOop depending on UseCompressedOops.
203 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset,
204 arrayOop d, size_t dst_offset, int length, TRAPS) {
205 if (s == d) {
206 // since source and destination are equal we do not need conversion checks.
207 assert(length > 0, "sanity check");
208 ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
209 } else {
210 // We have to make sure all elements conform to the destination array
211 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
212 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
213 // Perform null check if dst is null-free but src has no such guarantee
214 bool null_check = ((!s->klass()->is_null_free_array_klass()) &&
215 d->klass()->is_null_free_array_klass());
216 if (stype == bound || stype->is_subtype_of(bound)) {
217 if (null_check) {
218 ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_NOTNULL>::oop_arraycopy(s, src_offset, d, dst_offset, length);
219 } else {
220 ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length);
221 }
222 } else {
223 if (null_check) {
224 ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST | ARRAYCOPY_NOTNULL>::oop_arraycopy(s, src_offset, d, dst_offset, length);
225 } else {
226 ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length);
227 }
228 }
229 }
230 }
231
232 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
233 int dst_pos, int length, TRAPS) {
234 assert(s->is_objArray(), "must be obj array");
235
236 if (UseFlatArray) {
237 if (d->is_flatArray()) {
238 FlatArrayKlass::cast(d->klass())->copy_array(s, src_pos, d, dst_pos, length, THREAD);
239 return;
240 }
241 }
242
243 if (!d->is_objArray()) {
244 ResourceMark rm(THREAD);
245 stringStream ss;
246 if (d->is_typeArray()) {
247 ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
248 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
249 } else {
250 ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
251 }
252 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
253 }
254
255 // Check is all offsets and lengths are non negative
256 if (src_pos < 0 || dst_pos < 0 || length < 0) {
257 // Pass specific exception reason.
258 ResourceMark rm(THREAD);
259 stringStream ss;
260 if (src_pos < 0) {
261 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
262 src_pos, s->length());
263 } else if (dst_pos < 0) {
264 ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
265 dst_pos, d->length());
266 } else {
267 ss.print("arraycopy: length %d is negative", length);
268 }
269 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
270 }
271 // Check if the ranges are valid
272 if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
273 (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
274 // Pass specific exception reason.
275 ResourceMark rm(THREAD);
276 stringStream ss;
277 if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
278 ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
279 (unsigned int) length + (unsigned int) src_pos, s->length());
280 } else {
281 ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
282 (unsigned int) length + (unsigned int) dst_pos, d->length());
283 }
284 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
285 }
286
287 // Special case. Boundary cases must be checked first
288 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
289 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
290 // points to the right of the last element.
291 if (length==0) {
292 return;
293 }
294 if (UseCompressedOops) {
295 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
296 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
297 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, nullptr) ==
298 objArrayOop(s)->obj_at_addr<narrowOop>(src_pos), "sanity");
299 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, nullptr) ==
300 objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos), "sanity");
301 do_copy(s, src_offset, d, dst_offset, length, CHECK);
302 } else {
303 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
304 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
305 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, nullptr) ==
306 objArrayOop(s)->obj_at_addr<oop>(src_pos), "sanity");
307 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, nullptr) ==
308 objArrayOop(d)->obj_at_addr<oop>(dst_pos), "sanity");
309 do_copy(s, src_offset, d, dst_offset, length, CHECK);
310 }
311 }
312
313 bool ObjArrayKlass::can_be_primary_super_slow() const {
314 if (!bottom_klass()->can_be_primary_super())
315 // array of interfaces
316 return false;
317 else
318 return Klass::can_be_primary_super_slow();
319 }
320
321 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots,
322 Array<InstanceKlass*>* transitive_interfaces) {
323 assert(transitive_interfaces == nullptr, "sanity");
324 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
325 const Array<Klass*>* elem_supers = element_klass()->secondary_supers();
326 int num_elem_supers = elem_supers == nullptr ? 0 : elem_supers->length();
327 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
328 if (num_secondaries == 2) {
329 // Must share this for correct bootstrapping!
330 set_secondary_supers(Universe::the_array_interfaces_array(),
331 Universe::the_array_interfaces_bitmap());
332 return nullptr;
333 } else {
334 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
335 secondaries->push(vmClasses::Cloneable_klass());
336 secondaries->push(vmClasses::Serializable_klass());
337 for (int i = 0; i < num_elem_supers; i++) {
338 Klass* elem_super = elem_supers->at(i);
339 Klass* array_super = elem_super->array_klass_or_null();
340 assert(array_super != nullptr, "must already have been created");
341 secondaries->push(array_super);
342 }
343 return secondaries;
344 }
345 }
346
347 void ObjArrayKlass::initialize(TRAPS) {
348 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
349 }
350
351 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
352 ArrayKlass::metaspace_pointers_do(it);
353 it->push(&_element_klass);
354 it->push(&_bottom_klass);
355 }
356
357 jint ObjArrayKlass::compute_modifier_flags() const {
358 // The modifier for an objectArray is the same as its element
359 // With the addition of ACC_IDENTITY
360 if (element_klass() == nullptr) {
361 assert(Universe::is_bootstrapping(), "partial objArray only at startup");
362 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
363 }
364 // Return the flags of the bottom element type.
365 jint element_flags = bottom_klass()->compute_modifier_flags();
366
367 int identity_flag = (Arguments::enable_preview()) ? JVM_ACC_IDENTITY : 0;
368
369 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
370 | (identity_flag | JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
371 }
372
373 ModuleEntry* ObjArrayKlass::module() const {
374 assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
375 // The array is defined in the module of its bottom class
376 return bottom_klass()->module();
377 }
378
379 PackageEntry* ObjArrayKlass::package() const {
380 assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
381 return bottom_klass()->package();
382 }
383
384 // Printing
385
386 void ObjArrayKlass::print_on(outputStream* st) const {
387 #ifndef PRODUCT
388 Klass::print_on(st);
389 st->print(" - element klass: ");
390 element_klass()->print_value_on(st);
391 st->cr();
392 #endif //PRODUCT
393 }
394
395 void ObjArrayKlass::print_value_on(outputStream* st) const {
396 assert(is_klass(), "must be klass");
397
398 element_klass()->print_value_on(st);
399 st->print("[]");
400 }
401
402 #ifndef PRODUCT
403
404 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
405 ArrayKlass::oop_print_on(obj, st);
406 assert(obj->is_objArray(), "must be objArray");
407 objArrayOop oa = objArrayOop(obj);
408 int print_len = MIN2(oa->length(), MaxElementPrintSize);
409 for(int index = 0; index < print_len; index++) {
410 st->print(" - %3d : ", index);
411 if (oa->obj_at(index) != nullptr) {
412 oa->obj_at(index)->print_value_on(st);
413 st->cr();
414 } else {
415 st->print_cr("null");
416 }
417 }
418 int remaining = oa->length() - print_len;
419 if (remaining > 0) {
420 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
421 }
422 }
423
424 #endif //PRODUCT
425
426 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
427 assert(obj->is_objArray(), "must be objArray");
428 st->print("a ");
429 element_klass()->print_value_on(st);
430 int len = objArrayOop(obj)->length();
431 st->print("[%d] ", len);
432 if (obj != nullptr) {
433 obj->print_address_on(st);
434 } else {
435 st->print_cr("null");
436 }
437 }
438
439 const char* ObjArrayKlass::internal_name() const {
440 return external_name();
441 }
442
443
444 // Verification
445
446 void ObjArrayKlass::verify_on(outputStream* st) {
447 ArrayKlass::verify_on(st);
448 guarantee(element_klass()->is_klass(), "should be klass");
449 guarantee(bottom_klass()->is_klass(), "should be klass");
450 Klass* bk = bottom_klass();
451 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass() || bk->is_flatArray_klass(),
452 "invalid bottom klass");
453 }
454
455 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
456 ArrayKlass::oop_verify_on(obj, st);
457 guarantee(obj->is_objArray(), "must be objArray");
458 guarantee(obj->is_null_free_array() || (!is_null_free_array_klass()), "null-free klass but not object");
459 objArrayOop oa = objArrayOop(obj);
460 for(int index = 0; index < oa->length(); index++) {
461 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
462 }
463 }