1 /*
  2  * Copyright (c) 1997, 2023, 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     Klass* element_super = element_klass->super();
 64     if (element_super != nullptr) {
 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 != nullptr;
 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() == nullptr) {
 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 = nullptr;
 81         {
 82           MutexUnlocker mu(MultiArray_lock);
 83           super_klass = element_super->array_klass(CHECK_NULL);
 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_NULL);
 87           }
 88           // Now retry from the beginning
 89           ek = element_klass->array_klass(n, CHECK_NULL);
 90         }  // re-lock
 91         return ObjArrayKlass::cast(ek);
 92       }
 93     } else {
 94       // The element type is already Object.  Object[] has direct super of Object.
 95       super_klass = vmClasses::Object_klass();
 96     }
 97   }
 98 
 99   // Create type name for klass.
100   Symbol* name = nullptr;
101   {
102     ResourceMark rm(THREAD);
103     char *name_str = element_klass->name()->as_C_string();
104     int len = element_klass->name()->utf8_length();
105     char *new_str = NEW_RESOURCE_ARRAY(char, len + 4);
106     int idx = 0;
107     new_str[idx++] = JVM_SIGNATURE_ARRAY;
108     if (element_klass->is_instance_klass()) { // it could be an array or simple type
109       new_str[idx++] = JVM_SIGNATURE_CLASS;
110     }
111     memcpy(&new_str[idx], name_str, len * sizeof(char));
112     idx += len;
113     if (element_klass->is_instance_klass()) {
114       new_str[idx++] = JVM_SIGNATURE_ENDCLASS;
115     }
116     new_str[idx++] = '\0';
117     name = SymbolTable::new_symbol(new_str);
118   }
119 
120   // Initialize instance variables
121   ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_NULL);
122 
123   ModuleEntry* module = oak->module();
124   assert(module != nullptr, "No module entry for array");
125 
126   // Call complete_create_array_klass after all instance variables has been initialized.
127   ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_NULL);
128 
129   // Add all classes to our internal class loader list here,
130   // including classes in the bootstrap (null) class loader.
131   // Do this step after creating the mirror so that if the
132   // mirror creation fails, loaded_classes_do() doesn't find
133   // an array class without a mirror.
134   loader_data->add_class(oak);
135 
136   return oak;
137 }
138 
139 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name) : ArrayKlass(name, Kind) {
140   set_dimension(n);
141   set_element_klass(element_klass);
142 
143   Klass* bk;
144   if (element_klass->is_objArray_klass()) {
145     bk = ObjArrayKlass::cast(element_klass)->bottom_klass();
146   } else {
147     bk = element_klass;
148   }
149   assert(bk != nullptr && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass");
150   set_bottom_klass(bk);
151   set_class_loader_data(bk->class_loader_data());
152 
153   set_layout_helper(array_layout_helper(T_OBJECT));
154   assert(is_array_klass(), "sanity");
155   assert(is_objArray_klass(), "sanity");
156 }
157 
158 size_t ObjArrayKlass::oop_size(oop obj) const {
159   assert(obj->is_objArray(), "must be object array");
160   return objArrayOop(obj)->object_size();
161 }
162 
163 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) {
164   check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
165   size_t size = objArrayOopDesc::object_size(length);
166   return (objArrayOop)Universe::heap()->array_allocate(this, size, length,
167                                                        /* do_zero */ true, THREAD);
168 }
169 
170 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
171   int length = *sizes;
172   ArrayKlass* ld_klass = lower_dimension();
173   // If length < 0 allocate will throw an exception.
174   objArrayOop array = allocate(length, CHECK_NULL);
175   objArrayHandle h_array (THREAD, array);
176   if (rank > 1) {
177     if (length != 0) {
178       for (int index = 0; index < length; index++) {
179         oop sub_array = ld_klass->multi_allocate(rank - 1, &sizes[1], CHECK_NULL);
180         h_array->obj_at_put(index, sub_array);
181       }
182     } else {
183       // Since this array dimension has zero length, nothing will be
184       // allocated, however the lower dimension values must be checked
185       // for illegal values.
186       for (int i = 0; i < rank - 1; ++i) {
187         sizes += 1;
188         if (*sizes < 0) {
189           THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes));
190         }
191       }
192     }
193   }
194   return h_array();
195 }
196 
197 // Either oop or narrowOop depending on UseCompressedOops.
198 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset,
199                             arrayOop d, size_t dst_offset, int length, TRAPS) {
200   if (s == d) {
201     // since source and destination are equal we do not need conversion checks.
202     assert(length > 0, "sanity check");
203     ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
204   } else {
205     // We have to make sure all elements conform to the destination array
206     Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
207     Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
208     if (stype == bound || stype->is_subtype_of(bound)) {
209       // elements are guaranteed to be subtypes, so no check necessary
210       ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length);
211     } else {
212       // slow case: need individual subtype checks
213       // note: don't use obj_at_put below because it includes a redundant store check
214       if (!ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length)) {
215         ResourceMark rm(THREAD);
216         stringStream ss;
217         if (!bound->is_subtype_of(stype)) {
218           ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]",
219                    stype->external_name(), bound->external_name());
220         } else {
221           // oop_arraycopy should return the index in the source array that
222           // contains the problematic oop.
223           ss.print("arraycopy: element type mismatch: can not cast one of the elements"
224                    " of %s[] to the type of the destination array, %s",
225                    stype->external_name(), bound->external_name());
226         }
227         THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
228       }
229     }
230   }
231 }
232 
233 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
234                                int dst_pos, int length, TRAPS) {
235   assert(s->is_objArray(), "must be obj array");
236 
237   if (!d->is_objArray()) {
238     ResourceMark rm(THREAD);
239     stringStream ss;
240     if (d->is_typeArray()) {
241       ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
242                type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
243     } else {
244       ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
245     }
246     THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
247   }
248 
249   // Check is all offsets and lengths are non negative
250   if (src_pos < 0 || dst_pos < 0 || length < 0) {
251     // Pass specific exception reason.
252     ResourceMark rm(THREAD);
253     stringStream ss;
254     if (src_pos < 0) {
255       ss.print("arraycopy: source index %d out of bounds for object array[%d]",
256                src_pos, s->length());
257     } else if (dst_pos < 0) {
258       ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
259                dst_pos, d->length());
260     } else {
261       ss.print("arraycopy: length %d is negative", length);
262     }
263     THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
264   }
265   // Check if the ranges are valid
266   if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
267       (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
268     // Pass specific exception reason.
269     ResourceMark rm(THREAD);
270     stringStream ss;
271     if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
272       ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
273                (unsigned int) length + (unsigned int) src_pos, s->length());
274     } else {
275       ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
276                (unsigned int) length + (unsigned int) dst_pos, d->length());
277     }
278     THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
279   }
280 
281   // Special case. Boundary cases must be checked first
282   // This allows the following call: copy_array(s, s.length(), d.length(), 0).
283   // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
284   // points to the right of the last element.
285   if (length==0) {
286     return;
287   }
288   if (UseCompressedOops) {
289     size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
290     size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
291     assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, nullptr) ==
292            objArrayOop(s)->obj_at_addr<narrowOop>(src_pos), "sanity");
293     assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, nullptr) ==
294            objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos), "sanity");
295     do_copy(s, src_offset, d, dst_offset, length, CHECK);
296   } else {
297     size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
298     size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
299     assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, nullptr) ==
300            objArrayOop(s)->obj_at_addr<oop>(src_pos), "sanity");
301     assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, nullptr) ==
302            objArrayOop(d)->obj_at_addr<oop>(dst_pos), "sanity");
303     do_copy(s, src_offset, d, dst_offset, length, CHECK);
304   }
305 }
306 
307 bool ObjArrayKlass::can_be_primary_super_slow() const {
308   if (!bottom_klass()->can_be_primary_super())
309     // array of interfaces
310     return false;
311   else
312     return Klass::can_be_primary_super_slow();
313 }
314 
315 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots,
316                                                                Array<InstanceKlass*>* transitive_interfaces) {
317   assert(transitive_interfaces == nullptr, "sanity");
318   // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
319   const Array<Klass*>* elem_supers = element_klass()->secondary_supers();
320   int num_elem_supers = elem_supers == nullptr ? 0 : elem_supers->length();
321   int num_secondaries = num_extra_slots + 2 + num_elem_supers;
322   if (num_secondaries == 2) {
323     // Must share this for correct bootstrapping!
324     set_secondary_supers(Universe::the_array_interfaces_array());
325     return nullptr;
326   } else {
327     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
328     secondaries->push(vmClasses::Cloneable_klass());
329     secondaries->push(vmClasses::Serializable_klass());
330     for (int i = 0; i < num_elem_supers; i++) {
331       Klass* elem_super = elem_supers->at(i);
332       Klass* array_super = elem_super->array_klass_or_null();
333       assert(array_super != nullptr, "must already have been created");
334       secondaries->push(array_super);
335     }
336     return secondaries;
337   }
338 }
339 
340 void ObjArrayKlass::initialize(TRAPS) {
341   if (RecordTraining && bottom_klass()->is_instance_klass()) {
342     InstanceKlass* bk = InstanceKlass::cast(bottom_klass());
343     bk->record_initialization_touch("array", nullptr, nullptr,
344                                     this, nullptr, CHECK);
345   }
346   bottom_klass()->initialize(THREAD);  // dispatches to either InstanceKlass or TypeArrayKlass
347 }
348 
349 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
350   ArrayKlass::metaspace_pointers_do(it);
351   it->push(&_element_klass);
352   it->push(&_bottom_klass);
353 }
354 
355 jint ObjArrayKlass::compute_modifier_flags() const {
356   // The modifier for an objectArray is the same as its element
357   if (element_klass() == nullptr) {
358     assert(Universe::is_bootstrapping(), "partial objArray only at startup");
359     return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
360   }
361   // Return the flags of the bottom element type.
362   jint element_flags = bottom_klass()->compute_modifier_flags();
363 
364   return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
365                         | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
366 }
367 
368 ModuleEntry* ObjArrayKlass::module() const {
369   assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
370   // The array is defined in the module of its bottom class
371   return bottom_klass()->module();
372 }
373 
374 PackageEntry* ObjArrayKlass::package() const {
375   assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
376   return bottom_klass()->package();
377 }
378 
379 // Printing
380 
381 void ObjArrayKlass::print_on(outputStream* st) const {
382 #ifndef PRODUCT
383   Klass::print_on(st);
384   st->print(" - instance klass: ");
385   element_klass()->print_value_on(st);
386   st->cr();
387 #endif //PRODUCT
388 }
389 
390 void ObjArrayKlass::print_value_on(outputStream* st) const {
391   assert(is_klass(), "must be klass");
392 
393   element_klass()->print_value_on(st);
394   st->print("[]");
395 }
396 
397 #ifndef PRODUCT
398 
399 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
400   ArrayKlass::oop_print_on(obj, st);
401   assert(obj->is_objArray(), "must be objArray");
402   objArrayOop oa = objArrayOop(obj);
403   int print_len = MIN2(oa->length(), MaxElementPrintSize);
404   for(int index = 0; index < print_len; index++) {
405     st->print(" - %3d : ", index);
406     if (oa->obj_at(index) != nullptr) {
407       oa->obj_at(index)->print_value_on(st);
408       st->cr();
409     } else {
410       st->print_cr("null");
411     }
412   }
413   int remaining = oa->length() - print_len;
414   if (remaining > 0) {
415     st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
416   }
417 }
418 
419 #endif //PRODUCT
420 
421 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
422   assert(obj->is_objArray(), "must be objArray");
423   st->print("a ");
424   element_klass()->print_value_on(st);
425   int len = objArrayOop(obj)->length();
426   st->print("[%d] ", len);
427   if (obj != nullptr) {
428     obj->print_address_on(st);
429   } else {
430     st->print_cr("null");
431   }
432 }
433 
434 const char* ObjArrayKlass::internal_name() const {
435   return external_name();
436 }
437 
438 
439 // Verification
440 
441 void ObjArrayKlass::verify_on(outputStream* st) {
442   ArrayKlass::verify_on(st);
443   guarantee(element_klass()->is_klass(), "should be klass");
444   guarantee(bottom_klass()->is_klass(), "should be klass");
445   Klass* bk = bottom_klass();
446   guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(),  "invalid bottom klass");
447 }
448 
449 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
450   ArrayKlass::oop_verify_on(obj, st);
451   guarantee(obj->is_objArray(), "must be objArray");
452   objArrayOop oa = objArrayOop(obj);
453   for(int index = 0; index < oa->length(); index++) {
454     guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
455   }
456 }