1 /*
  2  * Copyright (c) 1997, 2025, 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 "classfile/moduleEntry.hpp"
 26 #include "classfile/packageEntry.hpp"
 27 #include "classfile/symbolTable.hpp"
 28 #include "classfile/vmClasses.hpp"
 29 #include "classfile/vmSymbols.hpp"
 30 #include "gc/shared/collectedHeap.inline.hpp"
 31 #include "memory/iterator.inline.hpp"
 32 #include "memory/metadataFactory.hpp"
 33 #include "memory/metaspaceClosure.hpp"

 34 #include "memory/resourceArea.hpp"
 35 #include "memory/universe.hpp"
 36 #include "oops/arrayKlass.hpp"



 37 #include "oops/instanceKlass.hpp"
 38 #include "oops/klass.inline.hpp"


 39 #include "oops/objArrayKlass.inline.hpp"
 40 #include "oops/objArrayOop.inline.hpp"
 41 #include "oops/oop.inline.hpp"


 42 #include "oops/symbol.hpp"

 43 #include "runtime/handles.inline.hpp"
 44 #include "runtime/mutexLocker.hpp"
 45 #include "utilities/macros.hpp"
 46 
 47 ObjArrayKlass* ObjArrayKlass::allocate_klass(ClassLoaderData* loader_data, int n, Klass* k, Symbol* name, TRAPS) {


 48   assert(ObjArrayKlass::header_size() <= InstanceKlass::header_size(),
 49       "array klasses must be same size as InstanceKlass");
 50 
 51   int size = ArrayKlass::static_size(ObjArrayKlass::header_size());
 52 
 53   return new (loader_data, size, THREAD) ObjArrayKlass(n, k, name);
 54 }
 55 
 56 Symbol* ObjArrayKlass::create_element_klass_array_name(JavaThread* current, Klass* element_klass) {
 57   ResourceMark rm(current);
 58   char* name_str = element_klass->name()->as_C_string();
 59   int len = element_klass->name()->utf8_length();
 60   char* new_str = NEW_RESOURCE_ARRAY_IN_THREAD(current, char, len + 4);
 61   int idx = 0;
 62   new_str[idx++] = JVM_SIGNATURE_ARRAY;
 63   if (element_klass->is_instance_klass()) { // it could be an array or simple type
 64     new_str[idx++] = JVM_SIGNATURE_CLASS;
 65   }
 66   memcpy(&new_str[idx], name_str, len * sizeof(char));
 67   idx += len;
 68   if (element_klass->is_instance_klass()) {
 69     new_str[idx++] = JVM_SIGNATURE_ENDCLASS;
 70   }
 71   new_str[idx] = '\0';
 72   return SymbolTable::new_symbol(new_str);
 73 }
 74 
 75 
 76 ObjArrayKlass* ObjArrayKlass::allocate_objArray_klass(ClassLoaderData* loader_data,
 77                                                       int n, Klass* element_klass, TRAPS) {
 78 
 79   // Eagerly allocate the direct array supertype.
 80   Klass* super_klass = nullptr;
 81   if (!Universe::is_bootstrapping() || vmClasses::Object_klass_is_loaded()) {
 82     assert(MultiArray_lock->holds_lock(THREAD), "must hold lock after bootstrapping");
 83     Klass* element_super = element_klass->super();
 84     if (element_super != nullptr) {
 85       // The element type has a direct super.  E.g., String[] has direct super of Object[].
 86       // Also, see if the element has secondary supertypes.
 87       // We need an array type for each before creating this array type.
 88       super_klass = element_super->array_klass(CHECK_NULL);
 89       const Array<Klass*>* element_supers = element_klass->secondary_supers();
 90       for (int i = element_supers->length() - 1; i >= 0; i--) {
 91         Klass* elem_super = element_supers->at(i);
 92         elem_super->array_klass(CHECK_NULL);
 93       }
 94       // Fall through because inheritance is acyclic and we hold the global recursive lock to allocate all the arrays.
 95     } else {
 96       // The element type is already Object.  Object[] has direct super of Object.
 97       super_klass = vmClasses::Object_klass();
 98     }
 99   }
100 
101   // Create type name for klass.
102   Symbol* name = create_element_klass_array_name(THREAD, element_klass);
103 
104   // Initialize instance variables
105   ObjArrayKlass* oak = ObjArrayKlass::allocate_klass(loader_data, n, element_klass, name, CHECK_NULL);
106 
107   ModuleEntry* module = oak->module();
108   assert(module != nullptr, "No module entry for array");
109 
110   // Call complete_create_array_klass after all instance variables has been initialized.
111   ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_NULL);
112 
113   // Add all classes to our internal class loader list here,
114   // including classes in the bootstrap (null) class loader.
115   // Do this step after creating the mirror so that if the
116   // mirror creation fails, loaded_classes_do() doesn't find
117   // an array class without a mirror.
118   loader_data->add_class(oak);
119 
120   return oak;
121 }
122 
123 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name) : ArrayKlass(n, name, Kind) {
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   // because size_given_klass() calls oop_size() on objects that might be
148   // concurrently forwarded, which would overwrite the Klass*.
149   assert(UseCompactObjectHeaders || obj->is_objArray(), "must be object array");
150   return objArrayOop(obj)->object_size();






































151 }
152 
153 objArrayOop ObjArrayKlass::allocate_instance(int length, TRAPS) {

















154   check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
155   size_t size = objArrayOopDesc::object_size(length);
156   return (objArrayOop)Universe::heap()->array_allocate(this, size, length,
157                                                        /* do_zero */ true, THREAD);








158 }
159 
160 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
161   int length = *sizes;
162   ArrayKlass* ld_klass = lower_dimension();
163   // If length < 0 allocate will throw an exception.
164   objArrayOop array = allocate_instance(length, CHECK_NULL);
165   objArrayHandle h_array (THREAD, array);


166   if (rank > 1) {
167     if (length != 0) {
168       for (int index = 0; index < length; index++) {
169         oop sub_array = ld_klass->multi_allocate(rank - 1, &sizes[1], CHECK_NULL);
170         h_array->obj_at_put(index, sub_array);
171       }
172     } else {
173       // Since this array dimension has zero length, nothing will be
174       // allocated, however the lower dimension values must be checked
175       // for illegal values.
176       for (int i = 0; i < rank - 1; ++i) {
177         sizes += 1;
178         if (*sizes < 0) {
179           THROW_MSG_NULL(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes));
180         }
181       }
182     }
183   }
184   return h_array();
185 }
186 
187 static void throw_array_store_exception(arrayOop src, arrayOop dst, TRAPS) {
188   ResourceMark rm(THREAD);
189   Klass* bound = ObjArrayKlass::cast(dst->klass())->element_klass();
190   Klass* stype = ObjArrayKlass::cast(src->klass())->element_klass();
191   stringStream ss;
192   if (!bound->is_subtype_of(stype)) {
193     ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
194              stype->external_name(), bound->external_name());
195   } else {
196     // oop_arraycopy should return the index in the source array that
197     // contains the problematic oop.
198     ss.print("arraycopy: element type mismatch: can not cast one of the elements"
199              " of %s[] to the type of the destination array, %s",
200              stype->external_name(), bound->external_name());
201   }
202   THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
203 }
204 
205 // Either oop or narrowOop depending on UseCompressedOops.
206 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset,
207                             arrayOop d, size_t dst_offset, int length, TRAPS) {
208   if (s == d) {
209     // since source and destination are equal we do not need conversion checks.
210     assert(length > 0, "sanity check");
211     OopCopyResult result = ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
212     assert(result == OopCopyResult::ok, "Should never fail");
213   } else {
214     // We have to make sure all elements conform to the destination array
215     Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
216     Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
217     bool type_check = stype != bound && !stype->is_subtype_of(bound);
218 
219     auto arraycopy = [&] {
220       if (type_check) {
221         return ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::
222             oop_arraycopy(s, src_offset, d, dst_offset, length);
223       } else {
224         return ArrayAccess<ARRAYCOPY_DISJOINT>::
225             oop_arraycopy(s, src_offset, d, dst_offset, length);
226       }
227     };
228 
229     OopCopyResult result = arraycopy();
230 
231     switch (result) {
232     case OopCopyResult::ok:
233       // Done
234       break;
235     case OopCopyResult::failed_check_class_cast:
236       throw_array_store_exception(s, d, JavaThread::current());
237       break;
238     default:
239       ShouldNotReachHere();
240     }
241   }
242 }
243 
244 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
245                                int dst_pos, int length, TRAPS) {
246   assert(s->is_objArray(), "must be obj array");
247 
248   if (!d->is_objArray()) {
249     ResourceMark rm(THREAD);
250     stringStream ss;
251     if (d->is_typeArray()) {
252       ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
253                type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
254     } else {
255       ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
256     }
257     THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
258   }
259 
260   // Check is all offsets and lengths are non negative
261   if (src_pos < 0 || dst_pos < 0 || length < 0) {
262     // Pass specific exception reason.
263     ResourceMark rm(THREAD);
264     stringStream ss;
265     if (src_pos < 0) {
266       ss.print("arraycopy: source index %d out of bounds for object array[%d]",
267                src_pos, s->length());
268     } else if (dst_pos < 0) {
269       ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
270                dst_pos, d->length());
271     } else {
272       ss.print("arraycopy: length %d is negative", length);
273     }
274     THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
275   }
276   // Check if the ranges are valid
277   if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
278       (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
279     // Pass specific exception reason.
280     ResourceMark rm(THREAD);
281     stringStream ss;
282     if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
283       ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
284                (unsigned int) length + (unsigned int) src_pos, s->length());
285     } else {
286       ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
287                (unsigned int) length + (unsigned int) dst_pos, d->length());
288     }
289     THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
290   }
291 
292   // Special case. Boundary cases must be checked first
293   // This allows the following call: copy_array(s, s.length(), d.length(), 0).
294   // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
295   // points to the right of the last element.
296   if (length==0) {
297     return;
298   }
299   if (UseCompressedOops) {
300     size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
301     size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
302     assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, nullptr) ==
303            objArrayOop(s)->obj_at_addr<narrowOop>(src_pos), "sanity");
304     assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, nullptr) ==
305            objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos), "sanity");
306     do_copy(s, src_offset, d, dst_offset, length, CHECK);
307   } else {
308     size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
309     size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
310     assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, nullptr) ==
311            objArrayOop(s)->obj_at_addr<oop>(src_pos), "sanity");
312     assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, nullptr) ==
313            objArrayOop(d)->obj_at_addr<oop>(dst_pos), "sanity");
314     do_copy(s, src_offset, d, dst_offset, length, CHECK);
315   }
316 }
317 
318 bool ObjArrayKlass::can_be_primary_super_slow() const {
319   if (!bottom_klass()->can_be_primary_super())
320     // array of interfaces
321     return false;
322   else
323     return Klass::can_be_primary_super_slow();
324 }
325 
326 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots,
327                                                                Array<InstanceKlass*>* transitive_interfaces) {
328   assert(transitive_interfaces == nullptr, "sanity");
329   // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
330   const Array<Klass*>* elem_supers = element_klass()->secondary_supers();
331   int num_elem_supers = elem_supers == nullptr ? 0 : elem_supers->length();
332   int num_secondaries = num_extra_slots + 2 + num_elem_supers;
333   if (num_secondaries == 2) {
334     // Must share this for correct bootstrapping!
335     set_secondary_supers(Universe::the_array_interfaces_array(),
336                          Universe::the_array_interfaces_bitmap());
337     return nullptr;
338   } else {
339     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
340     secondaries->push(vmClasses::Cloneable_klass());
341     secondaries->push(vmClasses::Serializable_klass());
342     for (int i = 0; i < num_elem_supers; i++) {
343       Klass* elem_super = elem_supers->at(i);
344       Klass* array_super = elem_super->array_klass_or_null();
345       assert(array_super != nullptr, "must already have been created");
346       secondaries->push(array_super);
347     }
348     return secondaries;
349   }
350 }
351 
352 void ObjArrayKlass::initialize(TRAPS) {
353   bottom_klass()->initialize(THREAD);  // dispatches to either InstanceKlass or TypeArrayKlass
354 }
355 
356 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
357   ArrayKlass::metaspace_pointers_do(it);
358   it->push(&_element_klass);
359   it->push(&_bottom_klass);



360 }
361 

























362 u2 ObjArrayKlass::compute_modifier_flags() const {
363   // The modifier for an objectArray is the same as its element
364   assert (element_klass() != nullptr, "should be initialized");
365 
366   // Return the flags of the bottom element type.
367   u2 element_flags = bottom_klass()->compute_modifier_flags();
368 


369   return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
370                         | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
371 }
372 
373 ModuleEntry* ObjArrayKlass::module() const {
374   assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
375   // The array is defined in the module of its bottom class
376   return bottom_klass()->module();
377 }
378 
379 PackageEntry* ObjArrayKlass::package() const {
380   assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
381   return bottom_klass()->package();
382 }
383 
























































384 // Printing
385 
386 void ObjArrayKlass::print_on(outputStream* st) const {
387 #ifndef PRODUCT
388   Klass::print_on(st);
389   st->print(" - instance klass: ");
390   element_klass()->print_value_on(st);
391   st->cr();
392 #endif //PRODUCT
393 }
394 
395 void ObjArrayKlass::print_value_on(outputStream* st) const {
396   assert(is_klass(), "must be klass");
397 
398   element_klass()->print_value_on(st);
399   st->print("[]");
400 }
401 
402 #ifndef PRODUCT
403 
404 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
405   ArrayKlass::oop_print_on(obj, st);
406   assert(obj->is_objArray(), "must be objArray");
407   objArrayOop oa = objArrayOop(obj);
408   int print_len = MIN2(oa->length(), MaxElementPrintSize);
409   for(int index = 0; index < print_len; index++) {
410     st->print(" - %3d : ", index);
411     if (oa->obj_at(index) != nullptr) {
412       oa->obj_at(index)->print_value_on(st);
413       st->cr();
414     } else {
415       st->print_cr("null");
416     }
417   }
418   int remaining = oa->length() - print_len;
419   if (remaining > 0) {
420     st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
421   }
422 }
423 
424 #endif //PRODUCT
425 
426 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
427   assert(obj->is_objArray(), "must be objArray");
428   st->print("a ");
429   element_klass()->print_value_on(st);
430   int len = objArrayOop(obj)->length();
431   st->print("[%d] ", len);
432   if (obj != nullptr) {
433     obj->print_address_on(st);
434   } else {
435     st->print_cr("null");
436   }
437 }
438 
439 const char* ObjArrayKlass::internal_name() const {
440   return external_name();
441 }
442 
443 
444 // Verification
445 
446 void ObjArrayKlass::verify_on(outputStream* st) {
447   ArrayKlass::verify_on(st);
448   guarantee(element_klass()->is_klass(), "should be klass");
449   guarantee(bottom_klass()->is_klass(), "should be klass");
450   Klass* bk = bottom_klass();
451   guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(),  "invalid bottom klass");

452 }
453 
454 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
455   ArrayKlass::oop_verify_on(obj, st);

456   guarantee(obj->is_objArray(), "must be objArray");
457   objArrayOop oa = objArrayOop(obj);
458   for(int index = 0; index < oa->length(); index++) {
459     guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
460   }
461 }
--- EOF ---