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 if (length >= 0) {
174 if (length <= arrayOopDesc::max_array_length(T_OBJECT)) {
175 int size = objArrayOopDesc::object_size(length);
176 return (objArrayOop)Universe::heap()->array_allocate(this, size, length,
177 /* do_zero */ true, THREAD);
178 } else {
179 report_java_out_of_memory("Requested array size exceeds VM limit");
180 JvmtiExport::post_array_size_exhausted();
181 THROW_OOP_0(Universe::out_of_memory_error_array_size());
182 }
183 } else {
184 THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", length));
185 }
186 }
187
188 static int multi_alloc_counter = 0;
189
190 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
191 int length = *sizes;
192 // Call to lower_dimension uses this pointer, so most be called before a
193 // possible GC
194 Klass* ld_klass = lower_dimension();
195 // If length < 0 allocate will throw an exception.
196 objArrayOop array = allocate(length, CHECK_NULL);
197 objArrayHandle h_array (THREAD, array);
198 if (rank > 1) {
199 if (length != 0) {
200 for (int index = 0; index < length; index++) {
201 ArrayKlass* ak = ArrayKlass::cast(ld_klass);
202 oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL);
203 h_array->obj_at_put(index, sub_array);
204 }
205 } else {
206 // Since this array dimension has zero length, nothing will be
207 // allocated, however the lower dimension values must be checked
208 // for illegal values.
209 for (int i = 0; i < rank - 1; ++i) {
210 sizes += 1;
211 if (*sizes < 0) {
212 THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes));
213 }
214 }
215 }
216 }
217 return h_array();
218 }
219
220 // Either oop or narrowOop depending on UseCompressedOops.
221 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset,
222 arrayOop d, size_t dst_offset, int length, TRAPS) {
223 if (oopDesc::equals(s, d)) {
224 // since source and destination are equal we do not need conversion checks.
225 assert(length > 0, "sanity check");
226 ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
227 } else {
228 // We have to make sure all elements conform to the destination array
229 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
230 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
231 if (stype == bound || stype->is_subtype_of(bound)) {
232 // elements are guaranteed to be subtypes, so no check necessary
233 ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length);
234 } else {
235 // slow case: need individual subtype checks
236 // note: don't use obj_at_put below because it includes a redundant store check
237 if (!ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length)) {
238 ResourceMark rm(THREAD);
239 stringStream ss;
240 if (!bound->is_subtype_of(stype)) {
241 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
242 stype->external_name(), bound->external_name());
243 } else {
244 // oop_arraycopy should return the index in the source array that
245 // contains the problematic oop.
246 ss.print("arraycopy: element type mismatch: can not cast one of the elements"
247 " of %s[] to the type of the destination array, %s",
248 stype->external_name(), bound->external_name());
249 }
250 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
251 }
252 }
253 }
254 }
255
256 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
257 int dst_pos, int length, TRAPS) {
258 assert(s->is_objArray(), "must be obj array");
259
260 if (!d->is_objArray()) {
261 ResourceMark rm(THREAD);
262 stringStream ss;
263 if (d->is_typeArray()) {
264 ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
265 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
266 } else {
267 ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
268 }
269 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
270 }
271
272 // Check is all offsets and lengths are non negative
273 if (src_pos < 0 || dst_pos < 0 || length < 0) {
274 // Pass specific exception reason.
275 ResourceMark rm(THREAD);
276 stringStream ss;
277 if (src_pos < 0) {
278 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
279 src_pos, s->length());
280 } else if (dst_pos < 0) {
281 ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
282 dst_pos, d->length());
283 } else {
284 ss.print("arraycopy: length %d is negative", length);
285 }
286 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
287 }
288 // Check if the ranges are valid
289 if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
290 (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
291 // Pass specific exception reason.
292 ResourceMark rm(THREAD);
293 stringStream ss;
294 if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
295 ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
296 (unsigned int) length + (unsigned int) src_pos, s->length());
297 } else {
298 ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
299 (unsigned int) length + (unsigned int) dst_pos, d->length());
300 }
301 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
302 }
303
304 // Special case. Boundary cases must be checked first
305 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
306 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
307 // points to the right of the last element.
308 if (length==0) {
309 return;
310 }
311 if (UseCompressedOops) {
312 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
313 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
314 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, NULL) ==
315 objArrayOop(s)->obj_at_addr_raw<narrowOop>(src_pos), "sanity");
316 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, NULL) ==
317 objArrayOop(d)->obj_at_addr_raw<narrowOop>(dst_pos), "sanity");
318 do_copy(s, src_offset, d, dst_offset, length, CHECK);
319 } else {
320 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
321 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
322 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, NULL) ==
323 objArrayOop(s)->obj_at_addr_raw<oop>(src_pos), "sanity");
324 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, NULL) ==
325 objArrayOop(d)->obj_at_addr_raw<oop>(dst_pos), "sanity");
326 do_copy(s, src_offset, d, dst_offset, length, CHECK);
327 }
328 }
329
330
331 Klass* ObjArrayKlass::array_klass_impl(bool or_null, int n, TRAPS) {
332
333 assert(dimension() <= n, "check order of chain");
334 int dim = dimension();
335 if (dim == n) return this;
336
337 // lock-free read needs acquire semantics
338 if (higher_dimension_acquire() == NULL) {
339 if (or_null) return NULL;
340
341 ResourceMark rm;
342 JavaThread *jt = (JavaThread *)THREAD;
343 {
344 MutexLocker mc(Compile_lock, THREAD); // for vtables
345 // Ensure atomic creation of higher dimensions
346 MutexLocker mu(MultiArray_lock, THREAD);
347
348 // Check if another thread beat us
349 if (higher_dimension() == NULL) {
350
351 // Create multi-dim klass object and link them together
352 Klass* k =
353 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL);
354 ObjArrayKlass* ak = ObjArrayKlass::cast(k);
355 ak->set_lower_dimension(this);
356 // use 'release' to pair with lock-free load
357 release_set_higher_dimension(ak);
358 assert(ak->is_objArray_klass(), "incorrect initialization of ObjArrayKlass");
359 }
360 }
361 } else {
362 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
363 }
364
365 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
366 if (or_null) {
367 return ak->array_klass_or_null(n);
368 }
369 return ak->array_klass(n, THREAD);
370 }
371
372 Klass* ObjArrayKlass::array_klass_impl(bool or_null, TRAPS) {
373 return array_klass_impl(or_null, dimension() + 1, THREAD);
374 }
375
376 bool ObjArrayKlass::can_be_primary_super_slow() const {
377 if (!bottom_klass()->can_be_primary_super())
378 // array of interfaces
379 return false;
380 else
381 return Klass::can_be_primary_super_slow();
382 }
383
384 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots,
385 Array<InstanceKlass*>* transitive_interfaces) {
386 assert(transitive_interfaces == NULL, "sanity");
387 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
388 const Array<Klass*>* elem_supers = element_klass()->secondary_supers();
389 int num_elem_supers = elem_supers == NULL ? 0 : elem_supers->length();
390 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
391 if (num_secondaries == 2) {
392 // Must share this for correct bootstrapping!
393 set_secondary_supers(Universe::the_array_interfaces_array());
394 return NULL;
395 } else {
396 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
397 secondaries->push(SystemDictionary::Cloneable_klass());
398 secondaries->push(SystemDictionary::Serializable_klass());
399 for (int i = 0; i < num_elem_supers; i++) {
400 Klass* elem_super = elem_supers->at(i);
401 Klass* array_super = elem_super->array_klass_or_null();
402 assert(array_super != NULL, "must already have been created");
403 secondaries->push(array_super);
404 }
405 return secondaries;
406 }
407 }
408
409 bool ObjArrayKlass::compute_is_subtype_of(Klass* k) {
410 if (!k->is_objArray_klass())
411 return ArrayKlass::compute_is_subtype_of(k);
412
413 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
414 return element_klass()->is_subtype_of(oak->element_klass());
415 }
416
417 void ObjArrayKlass::initialize(TRAPS) {
418 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
419 }
420
421 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
422 ArrayKlass::metaspace_pointers_do(it);
423 it->push(&_element_klass);
424 it->push(&_bottom_klass);
425 }
426
427 // JVM support
428
429 jint ObjArrayKlass::compute_modifier_flags(TRAPS) const {
430 // The modifier for an objectArray is the same as its element
431 if (element_klass() == NULL) {
432 assert(Universe::is_bootstrapping(), "partial objArray only at startup");
433 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
434 }
435 // Return the flags of the bottom element type.
436 jint element_flags = bottom_klass()->compute_modifier_flags(CHECK_0);
437
438 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
439 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
440 }
441
442 ModuleEntry* ObjArrayKlass::module() const {
443 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
444 // The array is defined in the module of its bottom class
445 return bottom_klass()->module();
446 }
447
448 PackageEntry* ObjArrayKlass::package() const {
449 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
450 return bottom_klass()->package();
451 }
452
453 // Printing
454
455 void ObjArrayKlass::print_on(outputStream* st) const {
456 #ifndef PRODUCT
457 Klass::print_on(st);
458 st->print(" - instance klass: ");
459 element_klass()->print_value_on(st);
460 st->cr();
461 #endif //PRODUCT
462 }
463
464 void ObjArrayKlass::print_value_on(outputStream* st) const {
465 assert(is_klass(), "must be klass");
466
467 element_klass()->print_value_on(st);
468 st->print("[]");
469 }
470
471 #ifndef PRODUCT
472
473 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
474 ArrayKlass::oop_print_on(obj, st);
475 assert(obj->is_objArray(), "must be objArray");
476 objArrayOop oa = objArrayOop(obj);
477 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize);
478 for(int index = 0; index < print_len; index++) {
479 st->print(" - %3d : ", index);
480 if (oa->obj_at(index) != NULL) {
481 oa->obj_at(index)->print_value_on(st);
482 st->cr();
483 } else {
484 st->print_cr("NULL");
485 }
486 }
487 int remaining = oa->length() - print_len;
488 if (remaining > 0) {
489 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
490 }
491 }
492
493 #endif //PRODUCT
494
495 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
496 assert(obj->is_objArray(), "must be objArray");
497 st->print("a ");
498 element_klass()->print_value_on(st);
499 int len = objArrayOop(obj)->length();
500 st->print("[%d] ", len);
501 if (obj != NULL) {
502 obj->print_address_on(st);
503 } else {
504 st->print_cr("NULL");
505 }
506 }
507
508 const char* ObjArrayKlass::internal_name() const {
509 return external_name();
510 }
511
512
513 // Verification
514
515 void ObjArrayKlass::verify_on(outputStream* st) {
516 ArrayKlass::verify_on(st);
517 guarantee(element_klass()->is_klass(), "should be klass");
518 guarantee(bottom_klass()->is_klass(), "should be klass");
519 Klass* bk = bottom_klass();
520 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(), "invalid bottom klass");
521 }
522
523 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
524 ArrayKlass::oop_verify_on(obj, st);
525 guarantee(obj->is_objArray(), "must be objArray");
526 objArrayOop oa = objArrayOop(obj);
527 for(int index = 0; index < oa->length(); index++) {
528 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
529 }
530 }