1 /*
2 * Copyright (c) 1997, 2024, 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/vmClasses.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.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 ObjArrayKlass* 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 = nullptr;
62 if (!Universe::is_bootstrapping() || vmClasses::Object_klass_loaded()) {
63 assert(MultiArray_lock->holds_lock(THREAD), "must hold lock after bootstrapping");
64 Klass* element_super = element_klass->super();
65 if (element_super != nullptr) {
66 // The element type has a direct super. E.g., String[] has direct super of Object[].
67 // Also, see if the element has secondary supertypes.
68 // We need an array type for each before creating this array type.
69 super_klass = element_super->array_klass(CHECK_NULL);
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 elem_super->array_klass(CHECK_NULL);
74 }
75 // Fall through because inheritance is acyclic and we hold the global recursive lock to allocate all the arrays.
76 } else {
77 // The element type is already Object. Object[] has direct super of Object.
78 super_klass = vmClasses::Object_klass();
79 }
80 }
81
82 // Create type name for klass.
83 Symbol* name = nullptr;
84 {
85 ResourceMark rm(THREAD);
86 char *name_str = element_klass->name()->as_C_string();
87 int len = element_klass->name()->utf8_length();
88 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4);
89 int idx = 0;
90 new_str[idx++] = JVM_SIGNATURE_ARRAY;
91 if (element_klass->is_instance_klass()) { // it could be an array or simple type
92 new_str[idx++] = JVM_SIGNATURE_CLASS;
93 }
94 memcpy(&new_str[idx], name_str, len * sizeof(char));
95 idx += len;
96 if (element_klass->is_instance_klass()) {
97 new_str[idx++] = JVM_SIGNATURE_ENDCLASS;
98 }
99 new_str[idx++] = '\0';
100 name = SymbolTable::new_symbol(new_str);
101 }
102
103 // Initialize instance variables
104 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_NULL);
105
106 ModuleEntry* module = oak->module();
107 assert(module != nullptr, "No module entry for array");
108
109 // Call complete_create_array_klass after all instance variables has been initialized.
110 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_NULL);
111
112 // Add all classes to our internal class loader list here,
113 // including classes in the bootstrap (null) class loader.
114 // Do this step after creating the mirror so that if the
115 // mirror creation fails, loaded_classes_do() doesn't find
116 // an array class without a mirror.
117 loader_data->add_class(oak);
118
119 return oak;
120 }
121
122 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name) : ArrayKlass(name, Kind) {
123 set_dimension(n);
124 set_element_klass(element_klass);
125
126 Klass* bk;
127 if (element_klass->is_objArray_klass()) {
128 bk = ObjArrayKlass::cast(element_klass)->bottom_klass();
129 } else {
130 bk = element_klass;
131 }
132 assert(bk != nullptr && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass");
133 set_bottom_klass(bk);
134 set_class_loader_data(bk->class_loader_data());
135
136 if (element_klass->is_array_klass()) {
137 set_lower_dimension(ArrayKlass::cast(element_klass));
138 }
139
140 set_layout_helper(array_layout_helper(T_OBJECT));
141 assert(is_array_klass(), "sanity");
142 assert(is_objArray_klass(), "sanity");
143 }
144
145 size_t ObjArrayKlass::oop_size(oop obj) const {
146 // In this assert, we cannot safely access the Klass* with compact headers.
147 assert(UseCompactObjectHeaders || obj->is_objArray(), "must be object array");
148 return objArrayOop(obj)->object_size();
149 }
150
151 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) {
152 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
153 size_t size = objArrayOopDesc::object_size(length);
154 return (objArrayOop)Universe::heap()->array_allocate(this, size, length,
155 /* do_zero */ true, THREAD);
156 }
157
158 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
159 int length = *sizes;
160 ArrayKlass* ld_klass = lower_dimension();
161 // If length < 0 allocate will throw an exception.
162 objArrayOop array = allocate(length, CHECK_NULL);
163 objArrayHandle h_array (THREAD, array);
164 if (rank > 1) {
165 if (length != 0) {
166 for (int index = 0; index < length; index++) {
167 oop sub_array = ld_klass->multi_allocate(rank - 1, &sizes[1], CHECK_NULL);
168 h_array->obj_at_put(index, sub_array);
169 }
170 } else {
171 // Since this array dimension has zero length, nothing will be
172 // allocated, however the lower dimension values must be checked
173 // for illegal values.
174 for (int i = 0; i < rank - 1; ++i) {
175 sizes += 1;
176 if (*sizes < 0) {
177 THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes));
178 }
179 }
180 }
181 }
182 return h_array();
183 }
184
185 // Either oop or narrowOop depending on UseCompressedOops.
186 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset,
187 arrayOop d, size_t dst_offset, int length, TRAPS) {
188 if (s == d) {
189 // since source and destination are equal we do not need conversion checks.
190 assert(length > 0, "sanity check");
191 ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
192 } else {
193 // We have to make sure all elements conform to the destination array
194 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
195 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
196 if (stype == bound || stype->is_subtype_of(bound)) {
197 // elements are guaranteed to be subtypes, so no check necessary
198 ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length);
199 } else {
200 // slow case: need individual subtype checks
201 // note: don't use obj_at_put below because it includes a redundant store check
202 if (!ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length)) {
203 ResourceMark rm(THREAD);
204 stringStream ss;
205 if (!bound->is_subtype_of(stype)) {
206 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
207 stype->external_name(), bound->external_name());
208 } else {
209 // oop_arraycopy should return the index in the source array that
210 // contains the problematic oop.
211 ss.print("arraycopy: element type mismatch: can not cast one of the elements"
212 " of %s[] to the type of the destination array, %s",
213 stype->external_name(), bound->external_name());
214 }
215 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
216 }
217 }
218 }
219 }
220
221 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
222 int dst_pos, int length, TRAPS) {
223 assert(s->is_objArray(), "must be obj array");
224
225 if (!d->is_objArray()) {
226 ResourceMark rm(THREAD);
227 stringStream ss;
228 if (d->is_typeArray()) {
229 ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
230 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
231 } else {
232 ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
233 }
234 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
235 }
236
237 // Check is all offsets and lengths are non negative
238 if (src_pos < 0 || dst_pos < 0 || length < 0) {
239 // Pass specific exception reason.
240 ResourceMark rm(THREAD);
241 stringStream ss;
242 if (src_pos < 0) {
243 ss.print("arraycopy: source index %d out of bounds for object array[%d]",
244 src_pos, s->length());
245 } else if (dst_pos < 0) {
246 ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
247 dst_pos, d->length());
248 } else {
249 ss.print("arraycopy: length %d is negative", length);
250 }
251 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
252 }
253 // Check if the ranges are valid
254 if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
255 (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
256 // Pass specific exception reason.
257 ResourceMark rm(THREAD);
258 stringStream ss;
259 if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
260 ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
261 (unsigned int) length + (unsigned int) src_pos, s->length());
262 } else {
263 ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
264 (unsigned int) length + (unsigned int) dst_pos, d->length());
265 }
266 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
267 }
268
269 // Special case. Boundary cases must be checked first
270 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
271 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
272 // points to the right of the last element.
273 if (length==0) {
274 return;
275 }
276 if (UseCompressedOops) {
277 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
278 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
279 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, nullptr) ==
280 objArrayOop(s)->obj_at_addr<narrowOop>(src_pos), "sanity");
281 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, nullptr) ==
282 objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos), "sanity");
283 do_copy(s, src_offset, d, dst_offset, length, CHECK);
284 } else {
285 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
286 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
287 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, nullptr) ==
288 objArrayOop(s)->obj_at_addr<oop>(src_pos), "sanity");
289 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, nullptr) ==
290 objArrayOop(d)->obj_at_addr<oop>(dst_pos), "sanity");
291 do_copy(s, src_offset, d, dst_offset, length, CHECK);
292 }
293 }
294
295 bool ObjArrayKlass::can_be_primary_super_slow() const {
296 if (!bottom_klass()->can_be_primary_super())
297 // array of interfaces
298 return false;
299 else
300 return Klass::can_be_primary_super_slow();
301 }
302
303 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots,
304 Array<InstanceKlass*>* transitive_interfaces) {
305 assert(transitive_interfaces == nullptr, "sanity");
306 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
307 const Array<Klass*>* elem_supers = element_klass()->secondary_supers();
308 int num_elem_supers = elem_supers == nullptr ? 0 : elem_supers->length();
309 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
310 if (num_secondaries == 2) {
311 // Must share this for correct bootstrapping!
312 set_secondary_supers(Universe::the_array_interfaces_array());
313 return nullptr;
314 } else {
315 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
316 secondaries->push(vmClasses::Cloneable_klass());
317 secondaries->push(vmClasses::Serializable_klass());
318 for (int i = 0; i < num_elem_supers; i++) {
319 Klass* elem_super = elem_supers->at(i);
320 Klass* array_super = elem_super->array_klass_or_null();
321 assert(array_super != nullptr, "must already have been created");
322 secondaries->push(array_super);
323 }
324 return secondaries;
325 }
326 }
327
328 void ObjArrayKlass::initialize(TRAPS) {
329 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
330 }
331
332 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
333 ArrayKlass::metaspace_pointers_do(it);
334 it->push(&_element_klass);
335 it->push(&_bottom_klass);
336 }
337
338 jint ObjArrayKlass::compute_modifier_flags() const {
339 // The modifier for an objectArray is the same as its element
340 if (element_klass() == nullptr) {
341 assert(Universe::is_bootstrapping(), "partial objArray only at startup");
342 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
343 }
344 // Return the flags of the bottom element type.
345 jint element_flags = bottom_klass()->compute_modifier_flags();
346
347 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
348 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
349 }
350
351 ModuleEntry* ObjArrayKlass::module() const {
352 assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
353 // The array is defined in the module of its bottom class
354 return bottom_klass()->module();
355 }
356
357 PackageEntry* ObjArrayKlass::package() const {
358 assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
359 return bottom_klass()->package();
360 }
361
362 // Printing
363
364 void ObjArrayKlass::print_on(outputStream* st) const {
365 #ifndef PRODUCT
366 Klass::print_on(st);
367 st->print(" - instance klass: ");
368 element_klass()->print_value_on(st);
369 st->cr();
370 #endif //PRODUCT
371 }
372
373 void ObjArrayKlass::print_value_on(outputStream* st) const {
374 assert(is_klass(), "must be klass");
375
376 element_klass()->print_value_on(st);
377 st->print("[]");
378 }
379
380 #ifndef PRODUCT
381
382 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
383 ArrayKlass::oop_print_on(obj, st);
384 assert(obj->is_objArray(), "must be objArray");
385 objArrayOop oa = objArrayOop(obj);
386 int print_len = MIN2(oa->length(), MaxElementPrintSize);
387 for(int index = 0; index < print_len; index++) {
388 st->print(" - %3d : ", index);
389 if (oa->obj_at(index) != nullptr) {
390 oa->obj_at(index)->print_value_on(st);
391 st->cr();
392 } else {
393 st->print_cr("null");
394 }
395 }
396 int remaining = oa->length() - print_len;
397 if (remaining > 0) {
398 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
399 }
400 }
401
402 #endif //PRODUCT
403
404 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
405 assert(obj->is_objArray(), "must be objArray");
406 st->print("a ");
407 element_klass()->print_value_on(st);
408 int len = objArrayOop(obj)->length();
409 st->print("[%d] ", len);
410 if (obj != nullptr) {
411 obj->print_address_on(st);
412 } else {
413 st->print_cr("null");
414 }
415 }
416
417 const char* ObjArrayKlass::internal_name() const {
418 return external_name();
419 }
420
421
422 // Verification
423
424 void ObjArrayKlass::verify_on(outputStream* st) {
425 ArrayKlass::verify_on(st);
426 guarantee(element_klass()->is_klass(), "should be klass");
427 guarantee(bottom_klass()->is_klass(), "should be klass");
428 Klass* bk = bottom_klass();
429 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(), "invalid bottom klass");
430 }
431
432 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
433 ArrayKlass::oop_verify_on(obj, st);
434 guarantee(obj->is_objArray(), "must be objArray");
435 objArrayOop oa = objArrayOop(obj);
436 for(int index = 0; index < oa->length(); index++) {
437 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
438 }
439 }