1 /*
2 * Copyright (c) 1997, 2020, 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/systemDictionary.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 Klass* 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() || SystemDictionary::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 ek;
92 }
93 } else {
94 // The element type is already Object. Object[] has direct super of Object.
95 super_klass = SystemDictionary::Object_klass();
96 }
97 }
98
99 // Create type name for klass.
100 Symbol* name = NULL;
101 if (!element_klass->is_instance_klass() ||
102 (name = InstanceKlass::cast(element_klass)->array_name()) == NULL) {
103
104 ResourceMark rm(THREAD);
105 char *name_str = element_klass->name()->as_C_string();
106 int len = element_klass->name()->utf8_length();
107 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4);
108 int idx = 0;
109 new_str[idx++] = JVM_SIGNATURE_ARRAY;
110 if (element_klass->is_instance_klass()) { // it could be an array or simple type
111 new_str[idx++] = JVM_SIGNATURE_CLASS;
112 }
113
114 memcpy(&new_str[idx], name_str, len * sizeof(char));
115 idx += len;
116
117 if (element_klass->is_instance_klass()) {
118 if (element_klass->is_hidden()) {
119 // the name of an array of hidden class is of the form "[L<N>;/<S>"
120 // <N> is the binary name of the original class file in internal form
121 // <S> is the suffix
122 int end_class = -1;
123 for (int j = idx-1; j > 0; j--) {
124 new_str[j+1] = new_str[j];
125 if (new_str[j] == '+') {
126 end_class = j;
127 break;
128 }
129 }
130 // Insert ';' before '+' character
131 assert(end_class > 0 && end_class < idx, "invalid hidden class name");
132 new_str[end_class] = JVM_SIGNATURE_ENDCLASS;
133 } else {
134 new_str[idx++] = JVM_SIGNATURE_ENDCLASS;
135 }
136 }
137
138 new_str[idx++] = '\0';
139 name = SymbolTable::new_permanent_symbol(new_str);
140 if (element_klass->is_instance_klass()) {
141 InstanceKlass* ik = InstanceKlass::cast(element_klass);
142 ik->set_array_name(name);
143 }
144 }
145
146 // Initialize instance variables
147 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_NULL);
148
149 ModuleEntry* module = oak->module();
150 assert(module != NULL, "No module entry for array");
151
152 // Call complete_create_array_klass after all instance variables has been initialized.
153 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_NULL);
154
155 // Add all classes to our internal class loader list here,
156 // including classes in the bootstrap (NULL) class loader.
157 // Do this step after creating the mirror so that if the
158 // mirror creation fails, loaded_classes_do() doesn't find
159 // an array class without a mirror.
160 loader_data->add_class(oak);
161
162 return oak;
163 }
164
165 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name) : ArrayKlass(name, ID) {
166 this->set_dimension(n);
167 this->set_element_klass(element_klass);
168 // decrement refcount because object arrays are not explicitly freed. The
169 // InstanceKlass array_name() keeps the name counted while the klass is
170 // loaded.
171 name->decrement_refcount();
172
173 Klass* bk;
174 if (element_klass->is_objArray_klass()) {
175 bk = ObjArrayKlass::cast(element_klass)->bottom_klass();
176 } else {
177 bk = element_klass;
178 }
179 assert(bk != NULL && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass");
180 this->set_bottom_klass(bk);
181 this->set_class_loader_data(bk->class_loader_data());
182
183 this->set_layout_helper(array_layout_helper(T_OBJECT));
184 assert(this->is_array_klass(), "sanity");
185 assert(this->is_objArray_klass(), "sanity");
186 }
187
188 int ObjArrayKlass::oop_size(oop obj) const {
189 assert(obj->is_objArray(), "must be object array");
190 return objArrayOop(obj)->object_size();
191 }
192
193 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) {
194 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
195 int size = objArrayOopDesc::object_size(length);
196 return (objArrayOop)Universe::heap()->array_allocate(this, size, length,
197 /* do_zero */ true, THREAD);
198 }
199
200 static int multi_alloc_counter = 0;
201
202 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
203 int length = *sizes;
204 // Call to lower_dimension uses this pointer, so most be called before a
205 // possible GC
206 Klass* ld_klass = lower_dimension();
207 // If length < 0 allocate will throw an exception.
208 objArrayOop array = allocate(length, CHECK_NULL);
209 objArrayHandle h_array (THREAD, array);
210 if (rank > 1) {
211 if (length != 0) {
212 for (int index = 0; index < length; index++) {
213 ArrayKlass* ak = ArrayKlass::cast(ld_klass);
214 oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL);
215 h_array->obj_at_put(index, sub_array);
216 }
217 } else {
218 // Since this array dimension has zero length, nothing will be
219 // allocated, however the lower dimension values must be checked
220 // for illegal values.
221 for (int i = 0; i < rank - 1; ++i) {
222 sizes += 1;
223 if (*sizes < 0) {
224 THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes));
225 }
226 }
227 }
228 }
229 return h_array();
230 }
231
232 // Either oop or narrowOop depending on UseCompressedOops.
233 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset,
234 arrayOop d, size_t dst_offset, int length, TRAPS) {
235 if (s == d) {
236 // since source and destination are equal we do not need conversion checks.
237 assert(length > 0, "sanity check");
238 ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
239 } else {
240 // We have to make sure all elements conform to the destination array
241 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
242 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
243 if (stype == bound || stype->is_subtype_of(bound)) {
244 // elements are guaranteed to be subtypes, so no check necessary
245 ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length);
246 } else {
247 // slow case: need individual subtype checks
248 // note: don't use obj_at_put below because it includes a redundant store check
249 if (!ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length)) {
250 ResourceMark rm(THREAD);
251 stringStream ss;
252 if (!bound->is_subtype_of(stype)) {
253 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
254 stype->external_name(), bound->external_name());
255 } else {
256 // oop_arraycopy should return the index in the source array that
257 // contains the problematic oop.
258 ss.print("arraycopy: element type mismatch: can not cast one of the elements"
259 " of %s[] to the type of the destination array, %s",
260 stype->external_name(), bound->external_name());
261 }
262 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
263 }
264 }
265 }
266 }
267
268 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
269 int dst_pos, int length, TRAPS) {
270 assert(s->is_objArray(), "must be obj array");
271
272 if (!d->is_objArray()) {
273 ResourceMark rm(THREAD);
274 stringStream ss;
275 if (d->is_typeArray()) {
276 ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
277 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
278 } else {
279 ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
280 }
281 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
282 }
283
284 // Check is all offsets and lengths are non negative
285 if (src_pos < 0 || dst_pos < 0 || length < 0) {
286 // Pass specific exception reason.
287 ResourceMark rm(THREAD);
288 stringStream ss;
289 if (src_pos < 0) {
290 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
291 src_pos, s->length());
292 } else if (dst_pos < 0) {
293 ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
294 dst_pos, d->length());
295 } else {
296 ss.print("arraycopy: length %d is negative", length);
297 }
298 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
299 }
300 // Check if the ranges are valid
301 if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
302 (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
303 // Pass specific exception reason.
304 ResourceMark rm(THREAD);
305 stringStream ss;
306 if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
307 ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
308 (unsigned int) length + (unsigned int) src_pos, s->length());
309 } else {
310 ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
311 (unsigned int) length + (unsigned int) dst_pos, d->length());
312 }
313 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
314 }
315
316 // Special case. Boundary cases must be checked first
317 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
318 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
319 // points to the right of the last element.
320 if (length==0) {
321 return;
322 }
323 if (UseCompressedOops) {
324 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
325 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
326 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, NULL) ==
327 objArrayOop(s)->obj_at_addr_raw<narrowOop>(src_pos), "sanity");
328 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, NULL) ==
329 objArrayOop(d)->obj_at_addr_raw<narrowOop>(dst_pos), "sanity");
330 do_copy(s, src_offset, d, dst_offset, length, CHECK);
331 } else {
332 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
333 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
334 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, NULL) ==
335 objArrayOop(s)->obj_at_addr_raw<oop>(src_pos), "sanity");
336 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, NULL) ==
337 objArrayOop(d)->obj_at_addr_raw<oop>(dst_pos), "sanity");
338 do_copy(s, src_offset, d, dst_offset, length, CHECK);
339 }
340 }
341
342
343 Klass* ObjArrayKlass::array_klass_impl(bool or_null, int n, TRAPS) {
344
345 assert(dimension() <= n, "check order of chain");
346 int dim = dimension();
347 if (dim == n) return this;
348
349 // lock-free read needs acquire semantics
350 if (higher_dimension_acquire() == NULL) {
351 if (or_null) return NULL;
352
353 ResourceMark rm;
354 JavaThread *jt = (JavaThread *)THREAD;
355 {
356 // Ensure atomic creation of higher dimensions
357 MutexLocker mu(THREAD, MultiArray_lock);
358
359 // Check if another thread beat us
360 if (higher_dimension() == NULL) {
361
362 // Create multi-dim klass object and link them together
363 Klass* k =
364 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL);
365 ObjArrayKlass* ak = ObjArrayKlass::cast(k);
366 ak->set_lower_dimension(this);
367 // use 'release' to pair with lock-free load
368 release_set_higher_dimension(ak);
369 assert(ak->is_objArray_klass(), "incorrect initialization of ObjArrayKlass");
370 }
371 }
372 }
373
374 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
375 if (or_null) {
376 return ak->array_klass_or_null(n);
377 }
378 THREAD->check_possible_safepoint();
379 return ak->array_klass(n, THREAD);
380 }
381
382 Klass* ObjArrayKlass::array_klass_impl(bool or_null, TRAPS) {
383 return array_klass_impl(or_null, dimension() + 1, THREAD);
384 }
385
386 bool ObjArrayKlass::can_be_primary_super_slow() const {
387 if (!bottom_klass()->can_be_primary_super())
388 // array of interfaces
389 return false;
390 else
391 return Klass::can_be_primary_super_slow();
392 }
393
394 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots,
395 Array<InstanceKlass*>* transitive_interfaces) {
396 assert(transitive_interfaces == NULL, "sanity");
397 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
398 const Array<Klass*>* elem_supers = element_klass()->secondary_supers();
399 int num_elem_supers = elem_supers == NULL ? 0 : elem_supers->length();
400 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
401 if (num_secondaries == 2) {
402 // Must share this for correct bootstrapping!
403 set_secondary_supers(Universe::the_array_interfaces_array());
404 return NULL;
405 } else {
406 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
407 secondaries->push(SystemDictionary::Cloneable_klass());
408 secondaries->push(SystemDictionary::Serializable_klass());
409 for (int i = 0; i < num_elem_supers; i++) {
410 Klass* elem_super = elem_supers->at(i);
411 Klass* array_super = elem_super->array_klass_or_null();
412 assert(array_super != NULL, "must already have been created");
413 secondaries->push(array_super);
414 }
415 return secondaries;
416 }
417 }
418
419 void ObjArrayKlass::initialize(TRAPS) {
420 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
421 }
422
423 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
424 ArrayKlass::metaspace_pointers_do(it);
425 it->push(&_element_klass);
426 it->push(&_bottom_klass);
427 }
428
429 // JVM support
430
431 jint ObjArrayKlass::compute_modifier_flags(TRAPS) const {
432 // The modifier for an objectArray is the same as its element
433 if (element_klass() == NULL) {
434 assert(Universe::is_bootstrapping(), "partial objArray only at startup");
435 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
436 }
437 // Return the flags of the bottom element type.
438 jint element_flags = bottom_klass()->compute_modifier_flags(CHECK_0);
439
440 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
441 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
442 }
443
444 ModuleEntry* ObjArrayKlass::module() const {
445 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
446 // The array is defined in the module of its bottom class
447 return bottom_klass()->module();
448 }
449
450 PackageEntry* ObjArrayKlass::package() const {
451 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
452 return bottom_klass()->package();
453 }
454
455 // Printing
456
457 void ObjArrayKlass::print_on(outputStream* st) const {
458 #ifndef PRODUCT
459 Klass::print_on(st);
460 st->print(" - instance klass: ");
461 element_klass()->print_value_on(st);
462 st->cr();
463 #endif //PRODUCT
464 }
465
466 void ObjArrayKlass::print_value_on(outputStream* st) const {
467 assert(is_klass(), "must be klass");
468
469 element_klass()->print_value_on(st);
470 st->print("[]");
471 }
472
473 #ifndef PRODUCT
474
475 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
476 ArrayKlass::oop_print_on(obj, st);
477 assert(obj->is_objArray(), "must be objArray");
478 objArrayOop oa = objArrayOop(obj);
479 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize);
480 for(int index = 0; index < print_len; index++) {
481 st->print(" - %3d : ", index);
482 if (oa->obj_at(index) != NULL) {
483 oa->obj_at(index)->print_value_on(st);
484 st->cr();
485 } else {
486 st->print_cr("NULL");
487 }
488 }
489 int remaining = oa->length() - print_len;
490 if (remaining > 0) {
491 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
492 }
493 }
494
495 #endif //PRODUCT
496
497 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
498 assert(obj->is_objArray(), "must be objArray");
499 st->print("a ");
500 element_klass()->print_value_on(st);
501 int len = objArrayOop(obj)->length();
502 st->print("[%d] ", len);
503 if (obj != NULL) {
504 obj->print_address_on(st);
505 } else {
506 st->print_cr("NULL");
507 }
508 }
509
510 const char* ObjArrayKlass::internal_name() const {
511 return external_name();
512 }
513
514
515 // Verification
516
517 void ObjArrayKlass::verify_on(outputStream* st) {
518 ArrayKlass::verify_on(st);
519 guarantee(element_klass()->is_klass(), "should be klass");
520 guarantee(bottom_klass()->is_klass(), "should be klass");
521 Klass* bk = bottom_klass();
522 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(), "invalid bottom klass");
523 }
524
525 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
526 ArrayKlass::oop_verify_on(obj, st);
527 guarantee(obj->is_objArray(), "must be objArray");
528 objArrayOop oa = objArrayOop(obj);
529 for(int index = 0; index < oa->length(); index++) {
530 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
531 }
532 }