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/resourceArea.hpp"
36 #include "memory/universe.hpp"
37 #include "oops/arrayKlass.inline.hpp"
38 #include "oops/instanceKlass.hpp"
39 #include "oops/klass.inline.hpp"
40 #include "oops/objArrayKlass.inline.hpp"
41 #include "oops/objArrayOop.inline.hpp"
42 #include "oops/oop.inline.hpp"
43 #include "oops/symbol.hpp"
44 #include "runtime/handles.inline.hpp"
45 #include "runtime/mutexLocker.hpp"
46 #include "utilities/macros.hpp"
47
48 ObjArrayKlass* ObjArrayKlass::allocate(ClassLoaderData* loader_data, int n, Klass* k, Symbol* name, TRAPS) {
49 assert(ObjArrayKlass::header_size() <= InstanceKlass::header_size(),
50 "array klasses must be same size as InstanceKlass");
51
52 int size = ArrayKlass::static_size(ObjArrayKlass::header_size());
53
54 return new (loader_data, size, THREAD) ObjArrayKlass(n, k, name);
55 }
56
57 ObjArrayKlass* ObjArrayKlass::allocate_objArray_klass(ClassLoaderData* loader_data,
58 int n, Klass* element_klass, TRAPS) {
59
60 // Eagerly allocate the direct array supertype.
61 Klass* super_klass = nullptr;
62 if (!Universe::is_bootstrapping() || vmClasses::Object_klass_loaded()) {
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 super_klass = element_super->array_klass_or_null();
67 bool supers_exist = super_klass != nullptr;
68 // Also, see if the element has secondary supertypes.
69 // We need an array type for each.
70 const Array<Klass*>* element_supers = element_klass->secondary_supers();
71 for( int i = element_supers->length()-1; i >= 0; i-- ) {
72 Klass* elem_super = element_supers->at(i);
73 if (elem_super->array_klass_or_null() == nullptr) {
74 supers_exist = false;
75 break;
76 }
77 }
78 if (!supers_exist) {
79 // Oops. Not allocated yet. Back out, allocate it, and retry.
80 Klass* ek = nullptr;
81 {
82 MutexUnlocker mu(MultiArray_lock);
83 super_klass = element_super->array_klass(CHECK_NULL);
84 for( int i = element_supers->length()-1; i >= 0; i-- ) {
85 Klass* elem_super = element_supers->at(i);
86 elem_super->array_klass(CHECK_NULL);
87 }
88 // Now retry from the beginning
89 ek = element_klass->array_klass(n, CHECK_NULL);
90 } // re-lock
91 return ObjArrayKlass::cast(ek);
92 }
93 } else {
94 // The element type is already Object. Object[] has direct super of Object.
95 super_klass = vmClasses::Object_klass();
96 }
97 }
98
99 // Create type name for klass.
100 Symbol* name = nullptr;
101 {
102 ResourceMark rm(THREAD);
103 char *name_str = element_klass->name()->as_C_string();
104 int len = element_klass->name()->utf8_length();
105 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4);
106 int idx = 0;
107 new_str[idx++] = JVM_SIGNATURE_ARRAY;
108 if (element_klass->is_instance_klass()) { // it could be an array or simple type
109 new_str[idx++] = JVM_SIGNATURE_CLASS;
110 }
111 memcpy(&new_str[idx], name_str, len * sizeof(char));
112 idx += len;
113 if (element_klass->is_instance_klass()) {
114 new_str[idx++] = JVM_SIGNATURE_ENDCLASS;
115 }
116 new_str[idx++] = '\0';
117 name = SymbolTable::new_symbol(new_str);
118 }
119
120 // Initialize instance variables
121 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_NULL);
122
123 ModuleEntry* module = oak->module();
124 assert(module != nullptr, "No module entry for array");
125
126 // Call complete_create_array_klass after all instance variables has been initialized.
127 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_NULL);
128
129 // Add all classes to our internal class loader list here,
130 // including classes in the bootstrap (null) class loader.
131 // Do this step after creating the mirror so that if the
132 // mirror creation fails, loaded_classes_do() doesn't find
133 // an array class without a mirror.
134 loader_data->add_class(oak);
135
136 return oak;
137 }
138
139 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name) : ArrayKlass(name, Kind) {
140 set_dimension(n);
141 set_element_klass(element_klass);
142
143 Klass* bk;
144 if (element_klass->is_objArray_klass()) {
145 bk = ObjArrayKlass::cast(element_klass)->bottom_klass();
146 } else {
147 bk = element_klass;
148 }
149 assert(bk != nullptr && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass");
150 set_bottom_klass(bk);
151 set_class_loader_data(bk->class_loader_data());
152
153 set_layout_helper(array_layout_helper(T_OBJECT));
154 assert(is_array_klass(), "sanity");
155 assert(is_objArray_klass(), "sanity");
156 }
157
158 size_t ObjArrayKlass::oop_size(oop obj) const {
159 // In this assert, we cannot safely access the Klass* with compact headers.
160 assert(UseCompactObjectHeaders || obj->is_objArray(), "must be object array");
161 return objArrayOop(obj)->object_size();
162 }
163
164 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) {
165 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
166 size_t size = objArrayOopDesc::object_size(length);
167 return (objArrayOop)Universe::heap()->array_allocate(this, size, length,
168 /* do_zero */ true, THREAD);
169 }
170
171 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
172 int length = *sizes;
173 // Call to lower_dimension uses this pointer, so most be called before a
174 // possible GC
175 Klass* ld_klass = lower_dimension();
176 // If length < 0 allocate will throw an exception.
177 objArrayOop array = allocate(length, CHECK_NULL);
178 objArrayHandle h_array (THREAD, array);
179 if (rank > 1) {
180 if (length != 0) {
181 for (int index = 0; index < length; index++) {
182 ArrayKlass* ak = ArrayKlass::cast(ld_klass);
183 oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL);
184 h_array->obj_at_put(index, sub_array);
185 }
186 } else {
187 // Since this array dimension has zero length, nothing will be
188 // allocated, however the lower dimension values must be checked
189 // for illegal values.
190 for (int i = 0; i < rank - 1; ++i) {
191 sizes += 1;
192 if (*sizes < 0) {
193 THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes));
194 }
195 }
196 }
197 }
198 return h_array();
199 }
200
201 // Either oop or narrowOop depending on UseCompressedOops.
202 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset,
203 arrayOop d, size_t dst_offset, int length, TRAPS) {
204 if (s == d) {
205 // since source and destination are equal we do not need conversion checks.
206 assert(length > 0, "sanity check");
207 ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
208 } else {
209 // We have to make sure all elements conform to the destination array
210 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
211 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
212 if (stype == bound || stype->is_subtype_of(bound)) {
213 // elements are guaranteed to be subtypes, so no check necessary
214 ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length);
215 } else {
216 // slow case: need individual subtype checks
217 // note: don't use obj_at_put below because it includes a redundant store check
218 if (!ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length)) {
219 ResourceMark rm(THREAD);
220 stringStream ss;
221 if (!bound->is_subtype_of(stype)) {
222 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
223 stype->external_name(), bound->external_name());
224 } else {
225 // oop_arraycopy should return the index in the source array that
226 // contains the problematic oop.
227 ss.print("arraycopy: element type mismatch: can not cast one of the elements"
228 " of %s[] to the type of the destination array, %s",
229 stype->external_name(), bound->external_name());
230 }
231 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
232 }
233 }
234 }
235 }
236
237 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
238 int dst_pos, int length, TRAPS) {
239 assert(s->is_objArray(), "must be obj array");
240
241 if (!d->is_objArray()) {
242 ResourceMark rm(THREAD);
243 stringStream ss;
244 if (d->is_typeArray()) {
245 ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
246 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
247 } else {
248 ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
249 }
250 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
251 }
252
253 // Check is all offsets and lengths are non negative
254 if (src_pos < 0 || dst_pos < 0 || length < 0) {
255 // Pass specific exception reason.
256 ResourceMark rm(THREAD);
257 stringStream ss;
258 if (src_pos < 0) {
259 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
260 src_pos, s->length());
261 } else if (dst_pos < 0) {
262 ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
263 dst_pos, d->length());
264 } else {
265 ss.print("arraycopy: length %d is negative", length);
266 }
267 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
268 }
269 // Check if the ranges are valid
270 if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
271 (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
272 // Pass specific exception reason.
273 ResourceMark rm(THREAD);
274 stringStream ss;
275 if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
276 ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
277 (unsigned int) length + (unsigned int) src_pos, s->length());
278 } else {
279 ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
280 (unsigned int) length + (unsigned int) dst_pos, d->length());
281 }
282 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
283 }
284
285 // Special case. Boundary cases must be checked first
286 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
287 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
288 // points to the right of the last element.
289 if (length==0) {
290 return;
291 }
292 if (UseCompressedOops) {
293 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
294 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
295 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, nullptr) ==
296 objArrayOop(s)->obj_at_addr<narrowOop>(src_pos), "sanity");
297 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, nullptr) ==
298 objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos), "sanity");
299 do_copy(s, src_offset, d, dst_offset, length, CHECK);
300 } else {
301 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
302 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
303 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, nullptr) ==
304 objArrayOop(s)->obj_at_addr<oop>(src_pos), "sanity");
305 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, nullptr) ==
306 objArrayOop(d)->obj_at_addr<oop>(dst_pos), "sanity");
307 do_copy(s, src_offset, d, dst_offset, length, CHECK);
308 }
309 }
310
311
312 Klass* ObjArrayKlass::array_klass(int n, TRAPS) {
313
314 assert(dimension() <= n, "check order of chain");
315 int dim = dimension();
316 if (dim == n) return this;
317
318 // lock-free read needs acquire semantics
319 if (higher_dimension_acquire() == nullptr) {
320
321 ResourceMark rm(THREAD);
322 {
323 // Ensure atomic creation of higher dimensions
324 MutexLocker mu(THREAD, MultiArray_lock);
325
326 // Check if another thread beat us
327 if (higher_dimension() == nullptr) {
328
329 // Create multi-dim klass object and link them together
330 Klass* k =
331 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL);
332 ObjArrayKlass* ak = ObjArrayKlass::cast(k);
333 ak->set_lower_dimension(this);
334 // use 'release' to pair with lock-free load
335 release_set_higher_dimension(ak);
336 assert(ak->is_objArray_klass(), "incorrect initialization of ObjArrayKlass");
337 }
338 }
339 }
340
341 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
342 THREAD->check_possible_safepoint();
343 return ak->array_klass(n, THREAD);
344 }
345
346 Klass* ObjArrayKlass::array_klass_or_null(int n) {
347
348 assert(dimension() <= n, "check order of chain");
349 int dim = dimension();
350 if (dim == n) return this;
351
352 // lock-free read needs acquire semantics
353 if (higher_dimension_acquire() == nullptr) {
354 return nullptr;
355 }
356
357 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
358 return ak->array_klass_or_null(n);
359 }
360
361 Klass* ObjArrayKlass::array_klass(TRAPS) {
362 return array_klass(dimension() + 1, THREAD);
363 }
364
365 Klass* ObjArrayKlass::array_klass_or_null() {
366 return array_klass_or_null(dimension() + 1);
367 }
368
369 bool ObjArrayKlass::can_be_primary_super_slow() const {
370 if (!bottom_klass()->can_be_primary_super())
371 // array of interfaces
372 return false;
373 else
374 return Klass::can_be_primary_super_slow();
375 }
376
377 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots,
378 Array<InstanceKlass*>* transitive_interfaces) {
379 assert(transitive_interfaces == nullptr, "sanity");
380 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
381 const Array<Klass*>* elem_supers = element_klass()->secondary_supers();
382 int num_elem_supers = elem_supers == nullptr ? 0 : elem_supers->length();
383 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
384 if (num_secondaries == 2) {
385 // Must share this for correct bootstrapping!
386 set_secondary_supers(Universe::the_array_interfaces_array());
387 return nullptr;
388 } else {
389 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
390 secondaries->push(vmClasses::Cloneable_klass());
391 secondaries->push(vmClasses::Serializable_klass());
392 for (int i = 0; i < num_elem_supers; i++) {
393 Klass* elem_super = elem_supers->at(i);
394 Klass* array_super = elem_super->array_klass_or_null();
395 assert(array_super != nullptr, "must already have been created");
396 secondaries->push(array_super);
397 }
398 return secondaries;
399 }
400 }
401
402 void ObjArrayKlass::initialize(TRAPS) {
403 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
404 }
405
406 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
407 ArrayKlass::metaspace_pointers_do(it);
408 it->push(&_element_klass);
409 it->push(&_bottom_klass);
410 }
411
412 jint ObjArrayKlass::compute_modifier_flags() const {
413 // The modifier for an objectArray is the same as its element
414 if (element_klass() == nullptr) {
415 assert(Universe::is_bootstrapping(), "partial objArray only at startup");
416 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
417 }
418 // Return the flags of the bottom element type.
419 jint element_flags = bottom_klass()->compute_modifier_flags();
420
421 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
422 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
423 }
424
425 ModuleEntry* ObjArrayKlass::module() const {
426 assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
427 // The array is defined in the module of its bottom class
428 return bottom_klass()->module();
429 }
430
431 PackageEntry* ObjArrayKlass::package() const {
432 assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
433 return bottom_klass()->package();
434 }
435
436 // Printing
437
438 void ObjArrayKlass::print_on(outputStream* st) const {
439 #ifndef PRODUCT
440 Klass::print_on(st);
441 st->print(" - instance klass: ");
442 element_klass()->print_value_on(st);
443 st->cr();
444 #endif //PRODUCT
445 }
446
447 void ObjArrayKlass::print_value_on(outputStream* st) const {
448 assert(is_klass(), "must be klass");
449
450 element_klass()->print_value_on(st);
451 st->print("[]");
452 }
453
454 #ifndef PRODUCT
455
456 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
457 ArrayKlass::oop_print_on(obj, st);
458 assert(obj->is_objArray(), "must be objArray");
459 objArrayOop oa = objArrayOop(obj);
460 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize);
461 for(int index = 0; index < print_len; index++) {
462 st->print(" - %3d : ", index);
463 if (oa->obj_at(index) != nullptr) {
464 oa->obj_at(index)->print_value_on(st);
465 st->cr();
466 } else {
467 st->print_cr("null");
468 }
469 }
470 int remaining = oa->length() - print_len;
471 if (remaining > 0) {
472 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
473 }
474 }
475
476 #endif //PRODUCT
477
478 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
479 assert(obj->is_objArray(), "must be objArray");
480 st->print("a ");
481 element_klass()->print_value_on(st);
482 int len = objArrayOop(obj)->length();
483 st->print("[%d] ", len);
484 if (obj != nullptr) {
485 obj->print_address_on(st);
486 } else {
487 st->print_cr("null");
488 }
489 }
490
491 const char* ObjArrayKlass::internal_name() const {
492 return external_name();
493 }
494
495
496 // Verification
497
498 void ObjArrayKlass::verify_on(outputStream* st) {
499 ArrayKlass::verify_on(st);
500 guarantee(element_klass()->is_klass(), "should be klass");
501 guarantee(bottom_klass()->is_klass(), "should be klass");
502 Klass* bk = bottom_klass();
503 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(), "invalid bottom klass");
504 }
505
506 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
507 ArrayKlass::oop_verify_on(obj, st);
508 guarantee(obj->is_objArray(), "must be objArray");
509 objArrayOop oa = objArrayOop(obj);
510 for(int index = 0; index < oa->length(); index++) {
511 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
512 }
513 }