1 /*
2 * Copyright (c) 1997, 2021, 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 = NULL;
62 if (!Universe::is_bootstrapping() || vmClasses::Object_klass_loaded()) {
63 Klass* element_super = element_klass->super();
64 if (element_super != NULL) {
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 != NULL;
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() == NULL) {
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 = NULL;
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 = NULL;
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 != NULL, "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, ID) {
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 != NULL && (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 return objArrayOop(obj)->object_size();
160 }
161
162 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) {
163 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
164 size_t size = objArrayOopDesc::object_size(length);
165 return (objArrayOop)Universe::heap()->array_allocate(this, size, length,
166 /* do_zero */ true, THREAD);
167 }
168
169 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
170 int length = *sizes;
171 // Call to lower_dimension uses this pointer, so most be called before a
172 // possible GC
173 Klass* ld_klass = lower_dimension();
174 // If length < 0 allocate will throw an exception.
175 objArrayOop array = allocate(length, CHECK_NULL);
176 objArrayHandle h_array (THREAD, array);
177 if (rank > 1) {
178 if (length != 0) {
179 for (int index = 0; index < length; index++) {
180 ArrayKlass* ak = ArrayKlass::cast(ld_klass);
181 oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL);
182 h_array->obj_at_put(index, sub_array);
183 }
184 } else {
185 // Since this array dimension has zero length, nothing will be
186 // allocated, however the lower dimension values must be checked
187 // for illegal values.
188 for (int i = 0; i < rank - 1; ++i) {
189 sizes += 1;
190 if (*sizes < 0) {
191 THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes));
192 }
193 }
194 }
195 }
196 return h_array();
197 }
198
199 // Either oop or narrowOop depending on UseCompressedOops.
200 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset,
201 arrayOop d, size_t dst_offset, int length, TRAPS) {
202 if (s == d) {
203 // since source and destination are equal we do not need conversion checks.
204 assert(length > 0, "sanity check");
205 ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
206 } else {
207 // We have to make sure all elements conform to the destination array
208 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
209 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
210 if (stype == bound || stype->is_subtype_of(bound)) {
211 // elements are guaranteed to be subtypes, so no check necessary
212 ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length);
213 } else {
214 // slow case: need individual subtype checks
215 // note: don't use obj_at_put below because it includes a redundant store check
216 if (!ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length)) {
217 ResourceMark rm(THREAD);
218 stringStream ss;
219 if (!bound->is_subtype_of(stype)) {
220 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
221 stype->external_name(), bound->external_name());
222 } else {
223 // oop_arraycopy should return the index in the source array that
224 // contains the problematic oop.
225 ss.print("arraycopy: element type mismatch: can not cast one of the elements"
226 " of %s[] to the type of the destination array, %s",
227 stype->external_name(), bound->external_name());
228 }
229 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
230 }
231 }
232 }
233 }
234
235 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
236 int dst_pos, int length, TRAPS) {
237 assert(s->is_objArray(), "must be obj array");
238
239 if (!d->is_objArray()) {
240 ResourceMark rm(THREAD);
241 stringStream ss;
242 if (d->is_typeArray()) {
243 ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
244 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
245 } else {
246 ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
247 }
248 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
249 }
250
251 // Check is all offsets and lengths are non negative
252 if (src_pos < 0 || dst_pos < 0 || length < 0) {
253 // Pass specific exception reason.
254 ResourceMark rm(THREAD);
255 stringStream ss;
256 if (src_pos < 0) {
257 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
258 src_pos, s->length());
259 } else if (dst_pos < 0) {
260 ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
261 dst_pos, d->length());
262 } else {
263 ss.print("arraycopy: length %d is negative", length);
264 }
265 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
266 }
267 // Check if the ranges are valid
268 if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
269 (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
270 // Pass specific exception reason.
271 ResourceMark rm(THREAD);
272 stringStream ss;
273 if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
274 ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
275 (unsigned int) length + (unsigned int) src_pos, s->length());
276 } else {
277 ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
278 (unsigned int) length + (unsigned int) dst_pos, d->length());
279 }
280 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
281 }
282
283 // Special case. Boundary cases must be checked first
284 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
285 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
286 // points to the right of the last element.
287 if (length==0) {
288 return;
289 }
290 if (UseCompressedOops) {
291 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
292 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
293 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, NULL) ==
294 objArrayOop(s)->obj_at_addr<narrowOop>(src_pos), "sanity");
295 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, NULL) ==
296 objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos), "sanity");
297 do_copy(s, src_offset, d, dst_offset, length, CHECK);
298 } else {
299 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
300 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
301 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, NULL) ==
302 objArrayOop(s)->obj_at_addr<oop>(src_pos), "sanity");
303 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, NULL) ==
304 objArrayOop(d)->obj_at_addr<oop>(dst_pos), "sanity");
305 do_copy(s, src_offset, d, dst_offset, length, CHECK);
306 }
307 }
308
309
310 Klass* ObjArrayKlass::array_klass(int n, TRAPS) {
311
312 assert(dimension() <= n, "check order of chain");
313 int dim = dimension();
314 if (dim == n) return this;
315
316 // lock-free read needs acquire semantics
317 if (higher_dimension_acquire() == NULL) {
318
319 ResourceMark rm(THREAD);
320 {
321 // Ensure atomic creation of higher dimensions
322 MutexLocker mu(THREAD, MultiArray_lock);
323
324 // Check if another thread beat us
325 if (higher_dimension() == NULL) {
326
327 // Create multi-dim klass object and link them together
328 Klass* k =
329 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL);
330 ObjArrayKlass* ak = ObjArrayKlass::cast(k);
331 ak->set_lower_dimension(this);
332 // use 'release' to pair with lock-free load
333 release_set_higher_dimension(ak);
334 assert(ak->is_objArray_klass(), "incorrect initialization of ObjArrayKlass");
335 }
336 }
337 }
338
339 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
340 THREAD->check_possible_safepoint();
341 return ak->array_klass(n, THREAD);
342 }
343
344 Klass* ObjArrayKlass::array_klass_or_null(int n) {
345
346 assert(dimension() <= n, "check order of chain");
347 int dim = dimension();
348 if (dim == n) return this;
349
350 // lock-free read needs acquire semantics
351 if (higher_dimension_acquire() == NULL) {
352 return NULL;
353 }
354
355 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
356 return ak->array_klass_or_null(n);
357 }
358
359 Klass* ObjArrayKlass::array_klass(TRAPS) {
360 return array_klass(dimension() + 1, THREAD);
361 }
362
363 Klass* ObjArrayKlass::array_klass_or_null() {
364 return array_klass_or_null(dimension() + 1);
365 }
366
367 bool ObjArrayKlass::can_be_primary_super_slow() const {
368 if (!bottom_klass()->can_be_primary_super())
369 // array of interfaces
370 return false;
371 else
372 return Klass::can_be_primary_super_slow();
373 }
374
375 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots,
376 Array<InstanceKlass*>* transitive_interfaces) {
377 assert(transitive_interfaces == NULL, "sanity");
378 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
379 const Array<Klass*>* elem_supers = element_klass()->secondary_supers();
380 int num_elem_supers = elem_supers == NULL ? 0 : elem_supers->length();
381 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
382 if (num_secondaries == 2) {
383 // Must share this for correct bootstrapping!
384 set_secondary_supers(Universe::the_array_interfaces_array());
385 return NULL;
386 } else {
387 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
388 secondaries->push(vmClasses::Cloneable_klass());
389 secondaries->push(vmClasses::Serializable_klass());
390 for (int i = 0; i < num_elem_supers; i++) {
391 Klass* elem_super = elem_supers->at(i);
392 Klass* array_super = elem_super->array_klass_or_null();
393 assert(array_super != NULL, "must already have been created");
394 secondaries->push(array_super);
395 }
396 return secondaries;
397 }
398 }
399
400 void ObjArrayKlass::initialize(TRAPS) {
401 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
402 }
403
404 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
405 ArrayKlass::metaspace_pointers_do(it);
406 it->push(&_element_klass);
407 it->push(&_bottom_klass);
408 }
409
410 jint ObjArrayKlass::compute_modifier_flags() const {
411 // The modifier for an objectArray is the same as its element
412 if (element_klass() == NULL) {
413 assert(Universe::is_bootstrapping(), "partial objArray only at startup");
414 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
415 }
416 // Return the flags of the bottom element type.
417 jint element_flags = bottom_klass()->compute_modifier_flags();
418
419 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
420 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
421 }
422
423 ModuleEntry* ObjArrayKlass::module() const {
424 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
425 // The array is defined in the module of its bottom class
426 return bottom_klass()->module();
427 }
428
429 PackageEntry* ObjArrayKlass::package() const {
430 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
431 return bottom_klass()->package();
432 }
433
434 // Printing
435
436 void ObjArrayKlass::print_on(outputStream* st) const {
437 #ifndef PRODUCT
438 Klass::print_on(st);
439 st->print(" - instance klass: ");
440 element_klass()->print_value_on(st);
441 st->cr();
442 #endif //PRODUCT
443 }
444
445 void ObjArrayKlass::print_value_on(outputStream* st) const {
446 assert(is_klass(), "must be klass");
447
448 element_klass()->print_value_on(st);
449 st->print("[]");
450 }
451
452 #ifndef PRODUCT
453
454 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
455 ArrayKlass::oop_print_on(obj, st);
456 assert(obj->is_objArray(), "must be objArray");
457 objArrayOop oa = objArrayOop(obj);
458 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize);
459 for(int index = 0; index < print_len; index++) {
460 st->print(" - %3d : ", index);
461 if (oa->obj_at(index) != NULL) {
462 oa->obj_at(index)->print_value_on(st);
463 st->cr();
464 } else {
465 st->print_cr("NULL");
466 }
467 }
468 int remaining = oa->length() - print_len;
469 if (remaining > 0) {
470 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
471 }
472 }
473
474 #endif //PRODUCT
475
476 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
477 assert(obj->is_objArray(), "must be objArray");
478 st->print("a ");
479 element_klass()->print_value_on(st);
480 int len = objArrayOop(obj)->length();
481 st->print("[%d] ", len);
482 if (obj != NULL) {
483 obj->print_address_on(st);
484 } else {
485 st->print_cr("NULL");
486 }
487 }
488
489 const char* ObjArrayKlass::internal_name() const {
490 return external_name();
491 }
492
493
494 // Verification
495
496 void ObjArrayKlass::verify_on(outputStream* st) {
497 ArrayKlass::verify_on(st);
498 guarantee(element_klass()->is_klass(), "should be klass");
499 guarantee(bottom_klass()->is_klass(), "should be klass");
500 Klass* bk = bottom_klass();
501 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(), "invalid bottom klass");
502 }
503
504 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
505 ArrayKlass::oop_verify_on(obj, st);
506 guarantee(obj->is_objArray(), "must be objArray");
507 objArrayOop oa = objArrayOop(obj);
508 for(int index = 0; index < oa->length(); index++) {
509 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
510 }
511 }