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 int ObjArrayKlass::oop_size(oop obj) const {
159 assert(UseCompactObjectHeaders || obj->is_objArray(), "must be object array");
160 return objArrayOop(obj)->object_size();
161 }
162
163 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) {
164 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
165 int size = objArrayOopDesc::object_size(length);
166 return (objArrayOop)Universe::heap()->array_allocate(this, size, length,
167 /* do_zero */ true, THREAD);
168 }
169
170 static int multi_alloc_counter = 0;
171
172 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
173 int length = *sizes;
174 // Call to lower_dimension uses this pointer, so most be called before a
175 // possible GC
176 Klass* ld_klass = lower_dimension();
177 // If length < 0 allocate will throw an exception.
178 objArrayOop array = allocate(length, CHECK_NULL);
179 objArrayHandle h_array (THREAD, array);
180 if (rank > 1) {
181 if (length != 0) {
182 for (int index = 0; index < length; index++) {
183 ArrayKlass* ak = ArrayKlass::cast(ld_klass);
184 oop sub_array = ak->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_0(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 if (stype == bound || stype->is_subtype_of(bound)) {
214 // elements are guaranteed to be subtypes, so no check necessary
215 ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length);
216 } else {
217 // slow case: need individual subtype checks
218 // note: don't use obj_at_put below because it includes a redundant store check
219 if (!ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length)) {
220 ResourceMark rm(THREAD);
221 stringStream ss;
222 if (!bound->is_subtype_of(stype)) {
223 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
224 stype->external_name(), bound->external_name());
225 } else {
226 // oop_arraycopy should return the index in the source array that
227 // contains the problematic oop.
228 ss.print("arraycopy: element type mismatch: can not cast one of the elements"
229 " of %s[] to the type of the destination array, %s",
230 stype->external_name(), bound->external_name());
231 }
232 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
233 }
234 }
235 }
236 }
237
238 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
239 int dst_pos, int length, TRAPS) {
240 assert(s->is_objArray(), "must be obj array");
241
242 if (!d->is_objArray()) {
243 ResourceMark rm(THREAD);
244 stringStream ss;
245 if (d->is_typeArray()) {
246 ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
247 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
248 } else {
249 ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
250 }
251 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
252 }
253
254 // Check is all offsets and lengths are non negative
255 if (src_pos < 0 || dst_pos < 0 || length < 0) {
256 // Pass specific exception reason.
257 ResourceMark rm(THREAD);
258 stringStream ss;
259 if (src_pos < 0) {
260 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
261 src_pos, s->length());
262 } else if (dst_pos < 0) {
263 ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
264 dst_pos, d->length());
265 } else {
266 ss.print("arraycopy: length %d is negative", length);
267 }
268 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
269 }
270 // Check if the ranges are valid
271 if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
272 (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
273 // Pass specific exception reason.
274 ResourceMark rm(THREAD);
275 stringStream ss;
276 if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
277 ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
278 (unsigned int) length + (unsigned int) src_pos, s->length());
279 } else {
280 ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
281 (unsigned int) length + (unsigned int) dst_pos, d->length());
282 }
283 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
284 }
285
286 // Special case. Boundary cases must be checked first
287 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
288 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
289 // points to the right of the last element.
290 if (length==0) {
291 return;
292 }
293 if (UseCompressedOops) {
294 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
295 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
296 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, NULL) ==
297 objArrayOop(s)->obj_at_addr<narrowOop>(src_pos), "sanity");
298 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, NULL) ==
299 objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos), "sanity");
300 do_copy(s, src_offset, d, dst_offset, length, CHECK);
301 } else {
302 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
303 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
304 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, NULL) ==
305 objArrayOop(s)->obj_at_addr<oop>(src_pos), "sanity");
306 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, NULL) ==
307 objArrayOop(d)->obj_at_addr<oop>(dst_pos), "sanity");
308 do_copy(s, src_offset, d, dst_offset, length, CHECK);
309 }
310 }
311
312
313 Klass* ObjArrayKlass::array_klass(int n, TRAPS) {
314
315 assert(dimension() <= n, "check order of chain");
316 int dim = dimension();
317 if (dim == n) return this;
318
319 // lock-free read needs acquire semantics
320 if (higher_dimension_acquire() == NULL) {
321
322 ResourceMark rm(THREAD);
323 {
324 // Ensure atomic creation of higher dimensions
325 MutexLocker mu(THREAD, MultiArray_lock);
326
327 // Check if another thread beat us
328 if (higher_dimension() == NULL) {
329
330 // Create multi-dim klass object and link them together
331 Klass* k =
332 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL);
333 ObjArrayKlass* ak = ObjArrayKlass::cast(k);
334 ak->set_lower_dimension(this);
335 // use 'release' to pair with lock-free load
336 release_set_higher_dimension(ak);
337 assert(ak->is_objArray_klass(), "incorrect initialization of ObjArrayKlass");
338 }
339 }
340 }
341
342 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
343 THREAD->check_possible_safepoint();
344 return ak->array_klass(n, THREAD);
345 }
346
347 Klass* ObjArrayKlass::array_klass_or_null(int n) {
348
349 assert(dimension() <= n, "check order of chain");
350 int dim = dimension();
351 if (dim == n) return this;
352
353 // lock-free read needs acquire semantics
354 if (higher_dimension_acquire() == NULL) {
355 return NULL;
356 }
357
358 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
359 return ak->array_klass_or_null(n);
360 }
361
362 Klass* ObjArrayKlass::array_klass(TRAPS) {
363 return array_klass(dimension() + 1, THREAD);
364 }
365
366 Klass* ObjArrayKlass::array_klass_or_null() {
367 return array_klass_or_null(dimension() + 1);
368 }
369
370 bool ObjArrayKlass::can_be_primary_super_slow() const {
371 if (!bottom_klass()->can_be_primary_super())
372 // array of interfaces
373 return false;
374 else
375 return Klass::can_be_primary_super_slow();
376 }
377
378 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots,
379 Array<InstanceKlass*>* transitive_interfaces) {
380 assert(transitive_interfaces == NULL, "sanity");
381 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
382 const Array<Klass*>* elem_supers = element_klass()->secondary_supers();
383 int num_elem_supers = elem_supers == NULL ? 0 : elem_supers->length();
384 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
385 if (num_secondaries == 2) {
386 // Must share this for correct bootstrapping!
387 set_secondary_supers(Universe::the_array_interfaces_array());
388 return NULL;
389 } else {
390 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
391 secondaries->push(vmClasses::Cloneable_klass());
392 secondaries->push(vmClasses::Serializable_klass());
393 for (int i = 0; i < num_elem_supers; i++) {
394 Klass* elem_super = elem_supers->at(i);
395 Klass* array_super = elem_super->array_klass_or_null();
396 assert(array_super != NULL, "must already have been created");
397 secondaries->push(array_super);
398 }
399 return secondaries;
400 }
401 }
402
403 void ObjArrayKlass::initialize(TRAPS) {
404 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
405 }
406
407 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
408 ArrayKlass::metaspace_pointers_do(it);
409 it->push(&_element_klass);
410 it->push(&_bottom_klass);
411 }
412
413 jint ObjArrayKlass::compute_modifier_flags() const {
414 // The modifier for an objectArray is the same as its element
415 if (element_klass() == NULL) {
416 assert(Universe::is_bootstrapping(), "partial objArray only at startup");
417 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
418 }
419 // Return the flags of the bottom element type.
420 jint element_flags = bottom_klass()->compute_modifier_flags();
421
422 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
423 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
424 }
425
426 ModuleEntry* ObjArrayKlass::module() const {
427 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
428 // The array is defined in the module of its bottom class
429 return bottom_klass()->module();
430 }
431
432 PackageEntry* ObjArrayKlass::package() const {
433 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
434 return bottom_klass()->package();
435 }
436
437 // Printing
438
439 void ObjArrayKlass::print_on(outputStream* st) const {
440 #ifndef PRODUCT
441 Klass::print_on(st);
442 st->print(" - instance klass: ");
443 element_klass()->print_value_on(st);
444 st->cr();
445 #endif //PRODUCT
446 }
447
448 void ObjArrayKlass::print_value_on(outputStream* st) const {
449 assert(is_klass(), "must be klass");
450
451 element_klass()->print_value_on(st);
452 st->print("[]");
453 }
454
455 #ifndef PRODUCT
456
457 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
458 ArrayKlass::oop_print_on(obj, st);
459 assert(obj->is_objArray(), "must be objArray");
460 objArrayOop oa = objArrayOop(obj);
461 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize);
462 for(int index = 0; index < print_len; index++) {
463 st->print(" - %3d : ", index);
464 if (oa->obj_at(index) != NULL) {
465 oa->obj_at(index)->print_value_on(st);
466 st->cr();
467 } else {
468 st->print_cr("NULL");
469 }
470 }
471 int remaining = oa->length() - print_len;
472 if (remaining > 0) {
473 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
474 }
475 }
476
477 #endif //PRODUCT
478
479 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
480 assert(obj->is_objArray(), "must be objArray");
481 st->print("a ");
482 element_klass()->print_value_on(st);
483 int len = objArrayOop(obj)->length();
484 st->print("[%d] ", len);
485 if (obj != NULL) {
486 obj->print_address_on(st);
487 } else {
488 st->print_cr("NULL");
489 }
490 }
491
492 const char* ObjArrayKlass::internal_name() const {
493 return external_name();
494 }
495
496
497 // Verification
498
499 void ObjArrayKlass::verify_on(outputStream* st) {
500 ArrayKlass::verify_on(st);
501 guarantee(element_klass()->is_klass(), "should be klass");
502 guarantee(bottom_klass()->is_klass(), "should be klass");
503 Klass* bk = bottom_klass();
504 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(), "invalid bottom klass");
505 }
506
507 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
508 ArrayKlass::oop_verify_on(obj, st);
509 guarantee(obj->is_objArray(), "must be objArray");
510 objArrayOop oa = objArrayOop(obj);
511 for(int index = 0; index < oa->length(); index++) {
512 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
513 }
514 }