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