1 /*
2 * Copyright (c) 1997, 2018, 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 MutexUnlocker mc(Compile_lock); // for vtables
84 super_klass = element_super->array_klass(CHECK_0);
85 for( int i = element_supers->length()-1; i >= 0; i-- ) {
86 Klass* elem_super = element_supers->at(i);
87 elem_super->array_klass(CHECK_0);
88 }
89 // Now retry from the beginning
90 ek = element_klass->array_klass(n, CHECK_0);
91 } // re-lock
92 return ek;
93 }
94 } else {
95 // The element type is already Object. Object[] has direct super of Object.
96 super_klass = SystemDictionary::Object_klass();
97 }
98 }
99
100 // Create type name for klass.
101 Symbol* name = NULL;
102 if (!element_klass->is_instance_klass() ||
103 (name = InstanceKlass::cast(element_klass)->array_name()) == NULL) {
104
105 ResourceMark rm(THREAD);
106 char *name_str = element_klass->name()->as_C_string();
107 int len = element_klass->name()->utf8_length();
108 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4);
109 int idx = 0;
110 new_str[idx++] = '[';
111 if (element_klass->is_instance_klass()) { // it could be an array or simple type
112 new_str[idx++] = 'L';
113 }
114 memcpy(&new_str[idx], name_str, len * sizeof(char));
115 idx += len;
116 if (element_klass->is_instance_klass()) {
117 new_str[idx++] = ';';
118 }
119 new_str[idx++] = '\0';
120 name = SymbolTable::new_permanent_symbol(new_str, CHECK_0);
121 if (element_klass->is_instance_klass()) {
122 InstanceKlass* ik = InstanceKlass::cast(element_klass);
123 ik->set_array_name(name);
124 }
125 }
126
127 // Initialize instance variables
128 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_0);
129
130 // Add all classes to our internal class loader list here,
131 // including classes in the bootstrap (NULL) class loader.
132 // GC walks these as strong roots.
133 loader_data->add_class(oak);
134
135 ModuleEntry* module = oak->module();
136 assert(module != NULL, "No module entry for array");
137
138 // Call complete_create_array_klass after all instance variables has been initialized.
139 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_0);
140
141 return oak;
142 }
143
144 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name) : ArrayKlass(name, ID) {
145 this->set_dimension(n);
146 this->set_element_klass(element_klass);
147 // decrement refcount because object arrays are not explicitly freed. The
148 // InstanceKlass array_name() keeps the name counted while the klass is
149 // loaded.
150 name->decrement_refcount();
151
152 Klass* bk;
153 if (element_klass->is_objArray_klass()) {
154 bk = ObjArrayKlass::cast(element_klass)->bottom_klass();
155 } else {
156 bk = element_klass;
157 }
158 assert(bk != NULL && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass");
159 this->set_bottom_klass(bk);
160 this->set_class_loader_data(bk->class_loader_data());
161
162 this->set_layout_helper(array_layout_helper(T_OBJECT));
163 assert(this->is_array_klass(), "sanity");
164 assert(this->is_objArray_klass(), "sanity");
165 }
166
167 int ObjArrayKlass::oop_size(oop obj) const {
168 assert(obj->is_objArray(), "must be object array");
169 return objArrayOop(obj)->object_size();
170 }
171
172 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) {
173 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_0);
174 int size = objArrayOopDesc::object_size(length);
175 return (objArrayOop)Universe::heap()->array_allocate(this, size, length,
176 /* do_zero */ true, THREAD);
177 }
178
179 static int multi_alloc_counter = 0;
180
181 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
182 int length = *sizes;
183 // Call to lower_dimension uses this pointer, so most be called before a
184 // possible GC
185 Klass* ld_klass = lower_dimension();
186 // If length < 0 allocate will throw an exception.
187 objArrayOop array = allocate(length, CHECK_NULL);
188 objArrayHandle h_array (THREAD, array);
189 if (rank > 1) {
190 if (length != 0) {
191 for (int index = 0; index < length; index++) {
192 ArrayKlass* ak = ArrayKlass::cast(ld_klass);
193 oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL);
194 h_array->obj_at_put(index, sub_array);
195 }
196 } else {
197 // Since this array dimension has zero length, nothing will be
198 // allocated, however the lower dimension values must be checked
199 // for illegal values.
200 for (int i = 0; i < rank - 1; ++i) {
201 sizes += 1;
202 if (*sizes < 0) {
203 THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes));
204 }
205 }
206 }
207 }
208 return h_array();
209 }
210
211 // Either oop or narrowOop depending on UseCompressedOops.
212 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset,
213 arrayOop d, size_t dst_offset, int length, TRAPS) {
214 if (oopDesc::equals(s, d)) {
215 // since source and destination are equal we do not need conversion checks.
216 assert(length > 0, "sanity check");
217 ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
218 } else {
219 // We have to make sure all elements conform to the destination array
220 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
221 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
222 if (stype == bound || stype->is_subtype_of(bound)) {
223 // elements are guaranteed to be subtypes, so no check necessary
224 ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length);
225 } else {
226 // slow case: need individual subtype checks
227 // note: don't use obj_at_put below because it includes a redundant store check
228 if (!ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length)) {
229 ResourceMark rm(THREAD);
230 stringStream ss;
231 if (!bound->is_subtype_of(stype)) {
232 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
233 stype->external_name(), bound->external_name());
234 } else {
235 // oop_arraycopy should return the index in the source array that
236 // contains the problematic oop.
237 ss.print("arraycopy: element type mismatch: can not cast one of the elements"
238 " of %s[] to the type of the destination array, %s",
239 stype->external_name(), bound->external_name());
240 }
241 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
242 }
243 }
244 }
245 }
246
247 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
248 int dst_pos, int length, TRAPS) {
249 assert(s->is_objArray(), "must be obj array");
250
251 if (!d->is_objArray()) {
252 ResourceMark rm(THREAD);
253 stringStream ss;
254 if (d->is_typeArray()) {
255 ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
256 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
257 } else {
258 ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
259 }
260 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
261 }
262
263 // Check is all offsets and lengths are non negative
264 if (src_pos < 0 || dst_pos < 0 || length < 0) {
265 // Pass specific exception reason.
266 ResourceMark rm(THREAD);
267 stringStream ss;
268 if (src_pos < 0) {
269 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
270 src_pos, s->length());
271 } else if (dst_pos < 0) {
272 ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
273 dst_pos, d->length());
274 } else {
275 ss.print("arraycopy: length %d is negative", length);
276 }
277 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
278 }
279 // Check if the ranges are valid
280 if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
281 (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
282 // Pass specific exception reason.
283 ResourceMark rm(THREAD);
284 stringStream ss;
285 if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
286 ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
287 (unsigned int) length + (unsigned int) src_pos, s->length());
288 } else {
289 ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
290 (unsigned int) length + (unsigned int) dst_pos, d->length());
291 }
292 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
293 }
294
295 // Special case. Boundary cases must be checked first
296 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
297 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
298 // points to the right of the last element.
299 if (length==0) {
300 return;
301 }
302 if (UseCompressedOops) {
303 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
304 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
305 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, NULL) ==
306 objArrayOop(s)->obj_at_addr_raw<narrowOop>(src_pos), "sanity");
307 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, NULL) ==
308 objArrayOop(d)->obj_at_addr_raw<narrowOop>(dst_pos), "sanity");
309 do_copy(s, src_offset, d, dst_offset, length, CHECK);
310 } else {
311 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
312 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
313 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, NULL) ==
314 objArrayOop(s)->obj_at_addr_raw<oop>(src_pos), "sanity");
315 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, NULL) ==
316 objArrayOop(d)->obj_at_addr_raw<oop>(dst_pos), "sanity");
317 do_copy(s, src_offset, d, dst_offset, length, CHECK);
318 }
319 }
320
321
322 Klass* ObjArrayKlass::array_klass_impl(bool or_null, int n, TRAPS) {
323
324 assert(dimension() <= n, "check order of chain");
325 int dim = dimension();
326 if (dim == n) return this;
327
328 // lock-free read needs acquire semantics
329 if (higher_dimension_acquire() == NULL) {
330 if (or_null) return NULL;
331
332 ResourceMark rm;
333 JavaThread *jt = (JavaThread *)THREAD;
334 {
335 MutexLocker mc(Compile_lock, THREAD); // for vtables
336 // Ensure atomic creation of higher dimensions
337 MutexLocker mu(MultiArray_lock, THREAD);
338
339 // Check if another thread beat us
340 if (higher_dimension() == NULL) {
341
342 // Create multi-dim klass object and link them together
343 Klass* k =
344 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL);
345 ObjArrayKlass* ak = ObjArrayKlass::cast(k);
346 ak->set_lower_dimension(this);
347 // use 'release' to pair with lock-free load
348 release_set_higher_dimension(ak);
349 assert(ak->is_objArray_klass(), "incorrect initialization of ObjArrayKlass");
350 }
351 }
352 } else {
353 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
354 }
355
356 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
357 if (or_null) {
358 return ak->array_klass_or_null(n);
359 }
360 return ak->array_klass(n, THREAD);
361 }
362
363 Klass* ObjArrayKlass::array_klass_impl(bool or_null, TRAPS) {
364 return array_klass_impl(or_null, dimension() + 1, THREAD);
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(SystemDictionary::Cloneable_klass());
389 secondaries->push(SystemDictionary::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 bool ObjArrayKlass::compute_is_subtype_of(Klass* k) {
401 if (!k->is_objArray_klass())
402 return ArrayKlass::compute_is_subtype_of(k);
403
404 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
405 return element_klass()->is_subtype_of(oak->element_klass());
406 }
407
408 void ObjArrayKlass::initialize(TRAPS) {
409 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
410 }
411
412 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
413 ArrayKlass::metaspace_pointers_do(it);
414 it->push(&_element_klass);
415 it->push(&_bottom_klass);
416 }
417
418 // JVM support
419
420 jint ObjArrayKlass::compute_modifier_flags(TRAPS) const {
421 // The modifier for an objectArray is the same as its element
422 if (element_klass() == NULL) {
423 assert(Universe::is_bootstrapping(), "partial objArray only at startup");
424 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
425 }
426 // Return the flags of the bottom element type.
427 jint element_flags = bottom_klass()->compute_modifier_flags(CHECK_0);
428
429 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
430 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
431 }
432
433 ModuleEntry* ObjArrayKlass::module() const {
434 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
435 // The array is defined in the module of its bottom class
436 return bottom_klass()->module();
437 }
438
439 PackageEntry* ObjArrayKlass::package() const {
440 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
441 return bottom_klass()->package();
442 }
443
444 // Printing
445
446 void ObjArrayKlass::print_on(outputStream* st) const {
447 #ifndef PRODUCT
448 Klass::print_on(st);
449 st->print(" - instance klass: ");
450 element_klass()->print_value_on(st);
451 st->cr();
452 #endif //PRODUCT
453 }
454
455 void ObjArrayKlass::print_value_on(outputStream* st) const {
456 assert(is_klass(), "must be klass");
457
458 element_klass()->print_value_on(st);
459 st->print("[]");
460 }
461
462 #ifndef PRODUCT
463
464 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
465 ArrayKlass::oop_print_on(obj, st);
466 assert(obj->is_objArray(), "must be objArray");
467 objArrayOop oa = objArrayOop(obj);
468 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize);
469 for(int index = 0; index < print_len; index++) {
470 st->print(" - %3d : ", index);
471 if (oa->obj_at(index) != NULL) {
472 oa->obj_at(index)->print_value_on(st);
473 st->cr();
474 } else {
475 st->print_cr("NULL");
476 }
477 }
478 int remaining = oa->length() - print_len;
479 if (remaining > 0) {
480 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
481 }
482 }
483
484 #endif //PRODUCT
485
486 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
487 assert(obj->is_objArray(), "must be objArray");
488 st->print("a ");
489 element_klass()->print_value_on(st);
490 int len = objArrayOop(obj)->length();
491 st->print("[%d] ", len);
492 if (obj != NULL) {
493 obj->print_address_on(st);
494 } else {
495 st->print_cr("NULL");
496 }
497 }
498
499 const char* ObjArrayKlass::internal_name() const {
500 return external_name();
501 }
502
503
504 // Verification
505
506 void ObjArrayKlass::verify_on(outputStream* st) {
507 ArrayKlass::verify_on(st);
508 guarantee(element_klass()->is_klass(), "should be klass");
509 guarantee(bottom_klass()->is_klass(), "should be klass");
510 Klass* bk = bottom_klass();
511 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(), "invalid bottom klass");
512 }
513
514 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
515 ArrayKlass::oop_verify_on(obj, st);
516 guarantee(obj->is_objArray(), "must be objArray");
517 objArrayOop oa = objArrayOop(obj);
518 for(int index = 0; index < oa->length(); index++) {
519 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
520 }
521 }