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
allocate(ClassLoaderData * loader_data,int n,Klass * k,Symbol * name,TRAPS)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
allocate_objArray_klass(ClassLoaderData * loader_data,int n,Klass * element_klass,TRAPS)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_0);
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_0);
87 }
88 // Now retry from the beginning
89 ek = element_klass->array_klass(n, CHECK_0);
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++] = '[';
110 if (element_klass->is_instance_klass()) { // it could be an array or simple type
111 new_str[idx++] = 'L';
112 }
113 memcpy(&new_str[idx], name_str, len * sizeof(char));
114 idx += len;
115 if (element_klass->is_instance_klass()) {
116 new_str[idx++] = ';';
117 }
118 new_str[idx++] = '\0';
119 name = SymbolTable::new_permanent_symbol(new_str, CHECK_0);
120 if (element_klass->is_instance_klass()) {
121 InstanceKlass* ik = InstanceKlass::cast(element_klass);
122 ik->set_array_name(name);
123 }
124 }
125
126 // Initialize instance variables
127 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_0);
128
129 // Add all classes to our internal class loader list here,
130 // including classes in the bootstrap (NULL) class loader.
131 // GC walks these as strong roots.
132 loader_data->add_class(oak);
133
134 ModuleEntry* module = oak->module();
135 assert(module != NULL, "No module entry for array");
136
137 // Call complete_create_array_klass after all instance variables has been initialized.
138 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_0);
139
140 return oak;
141 }
142
ObjArrayKlass(int n,Klass * element_klass,Symbol * name)143 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name) : ArrayKlass(name, ID) {
144 this->set_dimension(n);
145 this->set_element_klass(element_klass);
146 // decrement refcount because object arrays are not explicitly freed. The
147 // InstanceKlass array_name() keeps the name counted while the klass is
148 // loaded.
149 name->decrement_refcount();
150
151 Klass* bk;
152 if (element_klass->is_objArray_klass()) {
153 bk = ObjArrayKlass::cast(element_klass)->bottom_klass();
154 } else {
155 bk = element_klass;
156 }
157 assert(bk != NULL && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass");
158 this->set_bottom_klass(bk);
159 this->set_class_loader_data(bk->class_loader_data());
160
161 this->set_layout_helper(array_layout_helper(T_OBJECT));
162 assert(this->is_array_klass(), "sanity");
163 assert(this->is_objArray_klass(), "sanity");
164 }
165
oop_size(oop obj) const166 int ObjArrayKlass::oop_size(oop obj) const {
167 assert(obj->is_objArray(), "must be object array");
168 return objArrayOop(obj)->object_size();
169 }
170
allocate(int length,TRAPS)171 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) {
172 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_0);
173 int size = objArrayOopDesc::object_size(length);
174 return (objArrayOop)Universe::heap()->array_allocate(this, size, length,
175 /* do_zero */ true, THREAD);
176 }
177
178 static int multi_alloc_counter = 0;
179
multi_allocate(int rank,jint * sizes,TRAPS)180 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
181 int length = *sizes;
182 // Call to lower_dimension uses this pointer, so most be called before a
183 // possible GC
184 Klass* ld_klass = lower_dimension();
185 // If length < 0 allocate will throw an exception.
186 objArrayOop array = allocate(length, CHECK_NULL);
187 objArrayHandle h_array (THREAD, array);
188 if (rank > 1) {
189 if (length != 0) {
190 for (int index = 0; index < length; index++) {
191 ArrayKlass* ak = ArrayKlass::cast(ld_klass);
192 oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL);
193 h_array->obj_at_put(index, sub_array);
194 }
195 } else {
196 // Since this array dimension has zero length, nothing will be
197 // allocated, however the lower dimension values must be checked
198 // for illegal values.
199 for (int i = 0; i < rank - 1; ++i) {
200 sizes += 1;
201 if (*sizes < 0) {
202 THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes));
203 }
204 }
205 }
206 }
207 return h_array();
208 }
209
210 // Either oop or narrowOop depending on UseCompressedOops.
do_copy(arrayOop s,size_t src_offset,arrayOop d,size_t dst_offset,int length,TRAPS)211 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset,
212 arrayOop d, size_t dst_offset, int length, TRAPS) {
213 if (oopDesc::equals(s, d)) {
214 // since source and destination are equal we do not need conversion checks.
215 assert(length > 0, "sanity check");
216 ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
217 } else {
218 // We have to make sure all elements conform to the destination array
219 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
220 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
221 if (stype == bound || stype->is_subtype_of(bound)) {
222 // elements are guaranteed to be subtypes, so no check necessary
223 ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length);
224 } else {
225 // slow case: need individual subtype checks
226 // note: don't use obj_at_put below because it includes a redundant store check
227 if (!ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length)) {
228 ResourceMark rm(THREAD);
229 stringStream ss;
230 if (!bound->is_subtype_of(stype)) {
231 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
232 stype->external_name(), bound->external_name());
233 } else {
234 // oop_arraycopy should return the index in the source array that
235 // contains the problematic oop.
236 ss.print("arraycopy: element type mismatch: can not cast one of the elements"
237 " of %s[] to the type of the destination array, %s",
238 stype->external_name(), bound->external_name());
239 }
240 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
241 }
242 }
243 }
244 }
245
copy_array(arrayOop s,int src_pos,arrayOop d,int dst_pos,int length,TRAPS)246 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
247 int dst_pos, int length, TRAPS) {
248 assert(s->is_objArray(), "must be obj array");
249
250 if (!d->is_objArray()) {
251 ResourceMark rm(THREAD);
252 stringStream ss;
253 if (d->is_typeArray()) {
254 ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
255 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
256 } else {
257 ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
258 }
259 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
260 }
261
262 // Check is all offsets and lengths are non negative
263 if (src_pos < 0 || dst_pos < 0 || length < 0) {
264 // Pass specific exception reason.
265 ResourceMark rm(THREAD);
266 stringStream ss;
267 if (src_pos < 0) {
268 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
269 src_pos, s->length());
270 } else if (dst_pos < 0) {
271 ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
272 dst_pos, d->length());
273 } else {
274 ss.print("arraycopy: length %d is negative", length);
275 }
276 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
277 }
278 // Check if the ranges are valid
279 if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
280 (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
281 // Pass specific exception reason.
282 ResourceMark rm(THREAD);
283 stringStream ss;
284 if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
285 ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
286 (unsigned int) length + (unsigned int) src_pos, s->length());
287 } else {
288 ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
289 (unsigned int) length + (unsigned int) dst_pos, d->length());
290 }
291 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
292 }
293
294 // Special case. Boundary cases must be checked first
295 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
296 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
297 // points to the right of the last element.
298 if (length==0) {
299 return;
300 }
301 if (UseCompressedOops) {
302 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
303 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
304 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, NULL) ==
305 objArrayOop(s)->obj_at_addr_raw<narrowOop>(src_pos), "sanity");
306 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, NULL) ==
307 objArrayOop(d)->obj_at_addr_raw<narrowOop>(dst_pos), "sanity");
308 do_copy(s, src_offset, d, dst_offset, length, CHECK);
309 } else {
310 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
311 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
312 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, NULL) ==
313 objArrayOop(s)->obj_at_addr_raw<oop>(src_pos), "sanity");
314 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, NULL) ==
315 objArrayOop(d)->obj_at_addr_raw<oop>(dst_pos), "sanity");
316 do_copy(s, src_offset, d, dst_offset, length, CHECK);
317 }
318 }
319
320
array_klass_impl(bool or_null,int n,TRAPS)321 Klass* ObjArrayKlass::array_klass_impl(bool or_null, int n, TRAPS) {
322
323 assert(dimension() <= n, "check order of chain");
324 int dim = dimension();
325 if (dim == n) return this;
326
327 // lock-free read needs acquire semantics
328 if (higher_dimension_acquire() == NULL) {
329 if (or_null) return NULL;
330
331 ResourceMark rm;
332 JavaThread *jt = (JavaThread *)THREAD;
333 {
334 // Ensure atomic creation of higher dimensions
335 MutexLocker mu(MultiArray_lock, THREAD);
336
337 // Check if another thread beat us
338 if (higher_dimension() == NULL) {
339
340 // Create multi-dim klass object and link them together
341 Klass* k =
342 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL);
343 ObjArrayKlass* ak = ObjArrayKlass::cast(k);
344 ak->set_lower_dimension(this);
345 // use 'release' to pair with lock-free load
346 release_set_higher_dimension(ak);
347 assert(ak->is_objArray_klass(), "incorrect initialization of ObjArrayKlass");
348 }
349 }
350 } else {
351 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
352 }
353
354 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
355 if (or_null) {
356 return ak->array_klass_or_null(n);
357 }
358 return ak->array_klass(n, THREAD);
359 }
360
array_klass_impl(bool or_null,TRAPS)361 Klass* ObjArrayKlass::array_klass_impl(bool or_null, TRAPS) {
362 return array_klass_impl(or_null, dimension() + 1, THREAD);
363 }
364
can_be_primary_super_slow() const365 bool ObjArrayKlass::can_be_primary_super_slow() const {
366 if (!bottom_klass()->can_be_primary_super())
367 // array of interfaces
368 return false;
369 else
370 return Klass::can_be_primary_super_slow();
371 }
372
compute_secondary_supers(int num_extra_slots,Array<InstanceKlass * > * transitive_interfaces)373 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots,
374 Array<InstanceKlass*>* transitive_interfaces) {
375 assert(transitive_interfaces == NULL, "sanity");
376 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
377 const Array<Klass*>* elem_supers = element_klass()->secondary_supers();
378 int num_elem_supers = elem_supers == NULL ? 0 : elem_supers->length();
379 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
380 if (num_secondaries == 2) {
381 // Must share this for correct bootstrapping!
382 set_secondary_supers(Universe::the_array_interfaces_array());
383 return NULL;
384 } else {
385 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
386 secondaries->push(SystemDictionary::Cloneable_klass());
387 secondaries->push(SystemDictionary::Serializable_klass());
388 for (int i = 0; i < num_elem_supers; i++) {
389 Klass* elem_super = elem_supers->at(i);
390 Klass* array_super = elem_super->array_klass_or_null();
391 assert(array_super != NULL, "must already have been created");
392 secondaries->push(array_super);
393 }
394 return secondaries;
395 }
396 }
397
compute_is_subtype_of(Klass * k)398 bool ObjArrayKlass::compute_is_subtype_of(Klass* k) {
399 if (!k->is_objArray_klass())
400 return ArrayKlass::compute_is_subtype_of(k);
401
402 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
403 return element_klass()->is_subtype_of(oak->element_klass());
404 }
405
initialize(TRAPS)406 void ObjArrayKlass::initialize(TRAPS) {
407 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
408 }
409
metaspace_pointers_do(MetaspaceClosure * it)410 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
411 ArrayKlass::metaspace_pointers_do(it);
412 it->push(&_element_klass);
413 it->push(&_bottom_klass);
414 }
415
416 // JVM support
417
compute_modifier_flags(TRAPS) const418 jint ObjArrayKlass::compute_modifier_flags(TRAPS) const {
419 // The modifier for an objectArray is the same as its element
420 if (element_klass() == NULL) {
421 assert(Universe::is_bootstrapping(), "partial objArray only at startup");
422 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
423 }
424 // Return the flags of the bottom element type.
425 jint element_flags = bottom_klass()->compute_modifier_flags(CHECK_0);
426
427 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
428 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
429 }
430
module() const431 ModuleEntry* ObjArrayKlass::module() const {
432 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
433 // The array is defined in the module of its bottom class
434 return bottom_klass()->module();
435 }
436
package() const437 PackageEntry* ObjArrayKlass::package() const {
438 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass");
439 return bottom_klass()->package();
440 }
441
442 // Printing
443
print_on(outputStream * st) const444 void ObjArrayKlass::print_on(outputStream* st) const {
445 #ifndef PRODUCT
446 Klass::print_on(st);
447 st->print(" - instance klass: ");
448 element_klass()->print_value_on(st);
449 st->cr();
450 #endif //PRODUCT
451 }
452
print_value_on(outputStream * st) const453 void ObjArrayKlass::print_value_on(outputStream* st) const {
454 assert(is_klass(), "must be klass");
455
456 element_klass()->print_value_on(st);
457 st->print("[]");
458 }
459
460 #ifndef PRODUCT
461
oop_print_on(oop obj,outputStream * st)462 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
463 ArrayKlass::oop_print_on(obj, st);
464 assert(obj->is_objArray(), "must be objArray");
465 objArrayOop oa = objArrayOop(obj);
466 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize);
467 for(int index = 0; index < print_len; index++) {
468 st->print(" - %3d : ", index);
469 if (oa->obj_at(index) != NULL) {
470 oa->obj_at(index)->print_value_on(st);
471 st->cr();
472 } else {
473 st->print_cr("NULL");
474 }
475 }
476 int remaining = oa->length() - print_len;
477 if (remaining > 0) {
478 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
479 }
480 }
481
482 #endif //PRODUCT
483
oop_print_value_on(oop obj,outputStream * st)484 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
485 assert(obj->is_objArray(), "must be objArray");
486 st->print("a ");
487 element_klass()->print_value_on(st);
488 int len = objArrayOop(obj)->length();
489 st->print("[%d] ", len);
490 if (obj != NULL) {
491 obj->print_address_on(st);
492 } else {
493 st->print_cr("NULL");
494 }
495 }
496
internal_name() const497 const char* ObjArrayKlass::internal_name() const {
498 return external_name();
499 }
500
501
502 // Verification
503
verify_on(outputStream * st)504 void ObjArrayKlass::verify_on(outputStream* st) {
505 ArrayKlass::verify_on(st);
506 guarantee(element_klass()->is_klass(), "should be klass");
507 guarantee(bottom_klass()->is_klass(), "should be klass");
508 Klass* bk = bottom_klass();
509 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(), "invalid bottom klass");
510 }
511
oop_verify_on(oop obj,outputStream * st)512 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
513 ArrayKlass::oop_verify_on(obj, st);
514 guarantee(obj->is_objArray(), "must be objArray");
515 objArrayOop oa = objArrayOop(obj);
516 for(int index = 0; index < oa->length(); index++) {
517 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
518 }
519 }
520