1 /*
2 * Copyright (c) 1997, 2023, 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.inline.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, bool qdesc, TRAPS) {
63 assert(!null_free || (n == 1 && element_klass->is_inline_klass() && qdesc), "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 Klass* element_super = element_klass->super();
69 if (element_super != nullptr) {
70 // The element type has a direct super. E.g., String[] has direct super of Object[].
71 if (null_free) {
72 super_klass = element_klass->array_klass_or_null();
73 } else {
74 super_klass = element_super->array_klass_or_null();
75 }
76 bool supers_exist = super_klass != nullptr;
77 // Also, see if the element has secondary supertypes.
78 // We need an array type for each.
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 if (elem_super->array_klass_or_null() == nullptr) {
83 supers_exist = false;
84 break;
85 }
86 }
87 if (null_free) {
88 if (element_klass->array_klass_or_null() == nullptr) {
89 supers_exist = false;
90 }
91 }
92 if (!supers_exist) {
93 // Oops. Not allocated yet. Back out, allocate it, and retry.
94 Klass* ek = nullptr;
95 {
96 MutexUnlocker mu(MultiArray_lock);
97 if (null_free) {
98 element_klass->array_klass(CHECK_NULL);
99 } else {
100 element_super->array_klass(CHECK_NULL);
101 }
102 for( int i = element_supers->length()-1; i >= 0; i-- ) {
103 Klass* elem_super = element_supers->at(i);
104 elem_super->array_klass(CHECK_NULL);
105 }
106 // Now retry from the beginning
107 if (null_free) {
108 ek = InlineKlass::cast(element_klass)->value_array_klass(CHECK_NULL);
109 } else {
110 ek = element_klass->array_klass(n, CHECK_NULL);
111 }
112 } // re-lock
113 return ObjArrayKlass::cast(ek);
114 }
115 } else {
116 // The element type is already Object. Object[] has direct super of Object.
117 super_klass = vmClasses::Object_klass();
118 }
119 }
120
121 // Create type name for klass.
122 Symbol* name = ArrayKlass::create_element_klass_array_name(element_klass, qdesc, CHECK_NULL);
123
124 // Initialize instance variables
125 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, null_free, CHECK_NULL);
126
127 ModuleEntry* module = oak->module();
128 assert(module != nullptr, "No module entry for array");
129
130 // Call complete_create_array_klass after all instance variables has been initialized.
131 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_NULL);
132
133 // Add all classes to our internal class loader list here,
134 // including classes in the bootstrap (null) class loader.
135 // Do this step after creating the mirror so that if the
136 // mirror creation fails, loaded_classes_do() doesn't find
137 // an array class without a mirror.
138 loader_data->add_class(oak);
139
140 return oak;
141 }
142
143 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name, bool null_free) : ArrayKlass(name, Kind) {
144 set_dimension(n);
145 set_element_klass(element_klass);
146
147 assert(!null_free || name->is_Q_array_signature(), "sanity check");
148
149 Klass* bk;
150 if (element_klass->is_objArray_klass()) {
151 bk = ObjArrayKlass::cast(element_klass)->bottom_klass();
152 } else if (element_klass->is_flatArray_klass()) {
153 bk = FlatArrayKlass::cast(element_klass)->element_klass();
154 } else {
155 bk = element_klass;
156 }
157 assert(bk != nullptr && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass");
158 set_bottom_klass(bk);
159 set_class_loader_data(bk->class_loader_data());
160
161 int lh = array_layout_helper(T_OBJECT);
162 if (null_free) {
163 assert(n == 1, "Bytecode does not support null-free multi-dim");
164 lh = layout_helper_set_null_free(lh);
165 #ifdef _LP64
166 set_prototype_header(markWord::null_free_array_prototype());
167 assert(prototype_header().is_null_free_array(), "sanity");
168 #else
169 set_prototype_header(markWord::inline_type_prototype());
170 #endif
171 }
172 set_layout_helper(lh);
173 assert(is_array_klass(), "sanity");
174 assert(is_objArray_klass(), "sanity");
175 }
176
177 size_t ObjArrayKlass::oop_size(oop obj) const {
178 assert(obj->is_objArray(), "must be object array");
179 return objArrayOop(obj)->object_size();
180 }
181
182 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) {
183 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
184 size_t size = objArrayOopDesc::object_size(length);
185 bool populate_null_free = is_null_free_array_klass();
186 objArrayOop array = (objArrayOop)Universe::heap()->array_allocate(this, size, length,
187 /* do_zero */ true, CHECK_NULL);
188 objArrayHandle array_h(THREAD, array);
189 if (populate_null_free) {
190 assert(dimension() == 1, "Can only populate the final dimension");
191 assert(element_klass()->is_inline_klass(), "Unexpected");
192 assert(!element_klass()->is_array_klass(), "ArrayKlass unexpected here");
193 assert(!InlineKlass::cast(element_klass())->flatten_array(), "Expected flatArrayOop allocation");
194 element_klass()->initialize(CHECK_NULL);
195 // Populate default values...
196 instanceOop value = (instanceOop) InlineKlass::cast(element_klass())->default_value();
197 for (int i = 0; i < length; i++) {
198 array_h->obj_at_put(i, value);
199 }
200 }
201 return array_h();
202 }
203
204 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
205 int length = *sizes;
206 if (rank == 1) { // last dim may be flatArray, check if we have any special storage requirements
207 if (name()->char_at(1) != JVM_SIGNATURE_ARRAY && name()->is_Q_array_signature()) {
208 return oopFactory::new_valueArray(element_klass(), length, CHECK_NULL);
209 } else {
210 return oopFactory::new_objArray(element_klass(), length, CHECK_NULL);
211 }
212 }
213 guarantee(rank > 1, "Rank below 1");
214 // Call to lower_dimension uses this pointer, so most be called before a
215 // possible GC
216 Klass* ld_klass = lower_dimension();
217 // If length < 0 allocate will throw an exception.
218 objArrayOop array = allocate(length, CHECK_NULL);
219 objArrayHandle h_array (THREAD, array);
220 if (length != 0) {
221 for (int index = 0; index < length; index++) {
222 ArrayKlass* ak = ArrayKlass::cast(ld_klass);
223 oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL);
224 h_array->obj_at_put(index, sub_array);
225 }
226 } else {
227 // Since this array dimension has zero length, nothing will be
228 // allocated, however the lower dimension values must be checked
229 // for illegal values.
230 for (int i = 0; i < rank - 1; ++i) {
231 sizes += 1;
232 if (*sizes < 0) {
233 THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes));
234 }
235 }
236 }
237 return h_array();
238 }
239
240 // Either oop or narrowOop depending on UseCompressedOops.
241 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset,
242 arrayOop d, size_t dst_offset, int length, TRAPS) {
243 if (s == d) {
244 // since source and destination are equal we do not need conversion checks.
245 assert(length > 0, "sanity check");
246 ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
247 } else {
248 // We have to make sure all elements conform to the destination array
249 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
250 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
251 // Perform null check if dst is null-free but src has no such guarantee
252 bool null_check = ((!s->klass()->is_null_free_array_klass()) &&
253 d->klass()->is_null_free_array_klass());
254 if (stype == bound || stype->is_subtype_of(bound)) {
255 if (null_check) {
256 ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_NOTNULL>::oop_arraycopy(s, src_offset, d, dst_offset, length);
257 } else {
258 ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length);
259 }
260 } else {
261 if (null_check) {
262 ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST | ARRAYCOPY_NOTNULL>::oop_arraycopy(s, src_offset, d, dst_offset, length);
263 } else {
264 ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length);
265 }
266 }
267 }
268 }
269
270 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
271 int dst_pos, int length, TRAPS) {
272 assert(s->is_objArray(), "must be obj array");
273
274 if (UseFlatArray) {
275 if (d->is_flatArray()) {
276 FlatArrayKlass::cast(d->klass())->copy_array(s, src_pos, d, dst_pos, length, THREAD);
277 return;
278 }
279 }
280
281 if (!d->is_objArray()) {
282 ResourceMark rm(THREAD);
283 stringStream ss;
284 if (d->is_typeArray()) {
285 ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
286 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
287 } else {
288 ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
289 }
290 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
291 }
292
293 // Check is all offsets and lengths are non negative
294 if (src_pos < 0 || dst_pos < 0 || length < 0) {
295 // Pass specific exception reason.
296 ResourceMark rm(THREAD);
297 stringStream ss;
298 if (src_pos < 0) {
299 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
300 src_pos, s->length());
301 } else if (dst_pos < 0) {
302 ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
303 dst_pos, d->length());
304 } else {
305 ss.print("arraycopy: length %d is negative", length);
306 }
307 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
308 }
309 // Check if the ranges are valid
310 if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
311 (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
312 // Pass specific exception reason.
313 ResourceMark rm(THREAD);
314 stringStream ss;
315 if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
316 ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
317 (unsigned int) length + (unsigned int) src_pos, s->length());
318 } else {
319 ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
320 (unsigned int) length + (unsigned int) dst_pos, d->length());
321 }
322 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
323 }
324
325 // Special case. Boundary cases must be checked first
326 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
327 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
328 // points to the right of the last element.
329 if (length==0) {
330 return;
331 }
332 if (UseCompressedOops) {
333 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
334 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
335 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, nullptr) ==
336 objArrayOop(s)->obj_at_addr<narrowOop>(src_pos), "sanity");
337 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, nullptr) ==
338 objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos), "sanity");
339 do_copy(s, src_offset, d, dst_offset, length, CHECK);
340 } else {
341 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
342 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
343 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, nullptr) ==
344 objArrayOop(s)->obj_at_addr<oop>(src_pos), "sanity");
345 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, nullptr) ==
346 objArrayOop(d)->obj_at_addr<oop>(dst_pos), "sanity");
347 do_copy(s, src_offset, d, dst_offset, length, CHECK);
348 }
349 }
350
351
352 Klass* ObjArrayKlass::array_klass(int n, TRAPS) {
353 assert(dimension() <= n, "check order of chain");
354 int dim = dimension();
355 if (dim == n) return this;
356
357 // lock-free read needs acquire semantics
358 if (higher_dimension_acquire() == nullptr) {
359
360 ResourceMark rm(THREAD);
361 {
362 // Ensure atomic creation of higher dimensions
363 MutexLocker mu(THREAD, MultiArray_lock);
364
365 // Check if another thread beat us
366 if (higher_dimension() == nullptr) {
367
368 // Create multi-dim klass object and link them together
369 Klass* k = ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this,
370 false, this->name()->is_Q_array_signature(), CHECK_NULL);
371 ObjArrayKlass* ak = ObjArrayKlass::cast(k);
372 ak->set_lower_dimension(this);
373 // use 'release' to pair with lock-free load
374 release_set_higher_dimension(ak);
375 assert(ak->is_objArray_klass(), "incorrect initialization of ObjArrayKlass");
376 }
377 }
378 }
379
380 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
381 THREAD->check_possible_safepoint();
382 return ak->array_klass(n, THREAD);
383 }
384
385 Klass* ObjArrayKlass::array_klass_or_null(int n) {
386
387 assert(dimension() <= n, "check order of chain");
388 int dim = dimension();
389 if (dim == n) return this;
390
391 // lock-free read needs acquire semantics
392 if (higher_dimension_acquire() == nullptr) {
393 return nullptr;
394 }
395
396 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
397 return ak->array_klass_or_null(n);
398 }
399
400 Klass* ObjArrayKlass::array_klass(TRAPS) {
401 return array_klass(dimension() + 1, THREAD);
402 }
403
404 Klass* ObjArrayKlass::array_klass_or_null() {
405 return array_klass_or_null(dimension() + 1);
406 }
407
408 bool ObjArrayKlass::can_be_primary_super_slow() const {
409 if (!bottom_klass()->can_be_primary_super())
410 // array of interfaces
411 return false;
412 else
413 return Klass::can_be_primary_super_slow();
414 }
415
416 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots,
417 Array<InstanceKlass*>* transitive_interfaces) {
418 assert(transitive_interfaces == nullptr, "sanity");
419 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
420 const Array<Klass*>* elem_supers = element_klass()->secondary_supers();
421 int num_elem_supers = elem_supers == nullptr ? 0 : elem_supers->length();
422 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
423 if (num_secondaries == 2) {
424 // Must share this for correct bootstrapping!
425 set_secondary_supers(Universe::the_array_interfaces_array());
426 return nullptr;
427 } else {
428 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
429 secondaries->push(vmClasses::Cloneable_klass());
430 secondaries->push(vmClasses::Serializable_klass());
431 for (int i = 0; i < num_elem_supers; i++) {
432 Klass* elem_super = elem_supers->at(i);
433 Klass* array_super = elem_super->array_klass_or_null();
434 assert(array_super != nullptr, "must already have been created");
435 secondaries->push(array_super);
436 }
437 return secondaries;
438 }
439 }
440
441 void ObjArrayKlass::initialize(TRAPS) {
442 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
443 }
444
445 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
446 ArrayKlass::metaspace_pointers_do(it);
447 it->push(&_element_klass);
448 it->push(&_bottom_klass);
449 }
450
451 jint ObjArrayKlass::compute_modifier_flags() const {
452 // The modifier for an objectArray is the same as its element
453 if (element_klass() == nullptr) {
454 assert(Universe::is_bootstrapping(), "partial objArray only at startup");
455 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
456 }
457 // Return the flags of the bottom element type.
458 jint element_flags = bottom_klass()->compute_modifier_flags();
459
460 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
461 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
462 }
463
464 ModuleEntry* ObjArrayKlass::module() const {
465 assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
466 // The array is defined in the module of its bottom class
467 return bottom_klass()->module();
468 }
469
470 PackageEntry* ObjArrayKlass::package() const {
471 assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
472 return bottom_klass()->package();
473 }
474
475 // Printing
476
477 void ObjArrayKlass::print_on(outputStream* st) const {
478 #ifndef PRODUCT
479 Klass::print_on(st);
480 st->print(" - element klass: ");
481 element_klass()->print_value_on(st);
482 st->cr();
483 #endif //PRODUCT
484 }
485
486 void ObjArrayKlass::print_value_on(outputStream* st) const {
487 assert(is_klass(), "must be klass");
488
489 element_klass()->print_value_on(st);
490 st->print("[]");
491 }
492
493 #ifndef PRODUCT
494
495 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
496 ArrayKlass::oop_print_on(obj, st);
497 assert(obj->is_objArray(), "must be objArray");
498 objArrayOop oa = objArrayOop(obj);
499 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize);
500 for(int index = 0; index < print_len; index++) {
501 st->print(" - %3d : ", index);
502 if (oa->obj_at(index) != nullptr) {
503 oa->obj_at(index)->print_value_on(st);
504 st->cr();
505 } else {
506 st->print_cr("null");
507 }
508 }
509 int remaining = oa->length() - print_len;
510 if (remaining > 0) {
511 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
512 }
513 }
514
515 #endif //PRODUCT
516
517 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
518 assert(obj->is_objArray(), "must be objArray");
519 st->print("a ");
520 element_klass()->print_value_on(st);
521 int len = objArrayOop(obj)->length();
522 st->print("[%d] ", len);
523 if (obj != nullptr) {
524 obj->print_address_on(st);
525 } else {
526 st->print_cr("null");
527 }
528 }
529
530 const char* ObjArrayKlass::internal_name() const {
531 return external_name();
532 }
533
534
535 // Verification
536
537 void ObjArrayKlass::verify_on(outputStream* st) {
538 ArrayKlass::verify_on(st);
539 guarantee(element_klass()->is_klass(), "should be klass");
540 guarantee(bottom_klass()->is_klass(), "should be klass");
541 Klass* bk = bottom_klass();
542 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass() || bk->is_flatArray_klass(),
543 "invalid bottom klass");
544 }
545
546 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
547 ArrayKlass::oop_verify_on(obj, st);
548 guarantee(obj->is_objArray(), "must be objArray");
549 guarantee(obj->is_null_free_array() || (!is_null_free_array_klass()), "null-free klass but not object");
550 objArrayOop oa = objArrayOop(obj);
551 for(int index = 0; index < oa->length(); index++) {
552 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
553 }
554 }