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/oopFactory.hpp"
 36 #include "memory/resourceArea.hpp"
 37 #include "memory/universe.hpp"
 38 #include "oops/arrayKlass.hpp"
 39 #include "oops/instanceKlass.hpp"
 40 #include "oops/klass.inline.hpp"
 41 #include "oops/objArrayKlass.inline.hpp"
 42 #include "oops/objArrayOop.inline.hpp"
 43 #include "oops/oop.inline.hpp"
 44 #include "oops/symbol.hpp"
 45 #include "runtime/handles.inline.hpp"
 46 #include "runtime/mutexLocker.hpp"
 47 #include "utilities/macros.hpp"
 48 
 49 ObjArrayKlass* ObjArrayKlass::allocate(ClassLoaderData* loader_data, int n,
 50                                        Klass* k, Symbol* name, bool null_free,
 51                                        TRAPS) {
 52   assert(ObjArrayKlass::header_size() <= InstanceKlass::header_size(),
 53       "array klasses must be same size as InstanceKlass");
 54 
 55   int size = ArrayKlass::static_size(ObjArrayKlass::header_size());
 56 
 57   return new (loader_data, size, THREAD) ObjArrayKlass(n, k, name, null_free);
 58 }
 59 
 60 ObjArrayKlass* ObjArrayKlass::allocate_objArray_klass(ClassLoaderData* loader_data,
 61                                                       int n, Klass* element_klass,
 62                                                       bool null_free, TRAPS) {
 63   assert(!null_free || (n == 1 && element_klass->is_inline_klass()), "null-free unsupported");
 64 
 65   // Eagerly allocate the direct array supertype.
 66   Klass* super_klass = nullptr;
 67   if (!Universe::is_bootstrapping() || vmClasses::Object_klass_loaded()) {
 68     Klass* element_super = element_klass->super();
 69     if (element_super != nullptr) {
 70       // The element type has a direct super.  E.g., String[] has direct super of Object[].
 71       if (null_free) {
 72         super_klass = element_klass->array_klass_or_null();
 73       } else {
 74         super_klass = element_super->array_klass_or_null();
 75       }
 76       bool supers_exist = super_klass != nullptr;
 77       // Also, see if the element has secondary supertypes.
 78       // We need an array type for each.
 79       const Array<Klass*>* element_supers = element_klass->secondary_supers();
 80       for( int i = element_supers->length()-1; i >= 0; i-- ) {
 81         Klass* elem_super = element_supers->at(i);
 82         if (elem_super->array_klass_or_null() == nullptr) {
 83           supers_exist = false;
 84           break;
 85         }
 86       }
 87       if (null_free) {
 88         if (element_klass->array_klass_or_null() == nullptr) {
 89           supers_exist = false;
 90         }
 91       }
 92       if (!supers_exist) {
 93         // Oops.  Not allocated yet.  Back out, allocate it, and retry.
 94         Klass* ek = nullptr;
 95         {
 96           MutexUnlocker mu(MultiArray_lock);
 97           if (null_free) {
 98             element_klass->array_klass(CHECK_NULL);
 99           } else {
100             element_super->array_klass(CHECK_NULL);
101           }
102           for( int i = element_supers->length()-1; i >= 0; i-- ) {
103             Klass* elem_super = element_supers->at(i);
104             elem_super->array_klass(CHECK_NULL);
105           }
106           // Now retry from the beginning
107           if (null_free) {
108             ek = InlineKlass::cast(element_klass)->value_array_klass(CHECK_NULL);
109           } else {
110             ek = element_klass->array_klass(n, CHECK_NULL);
111           }
112         }  // re-lock
113         return ObjArrayKlass::cast(ek);
114       }
115     } else {
116       // The element type is already Object.  Object[] has direct super of Object.
117       super_klass = vmClasses::Object_klass();
118     }
119   }
120 
121   // Create type name for klass.
122   Symbol* name = ArrayKlass::create_element_klass_array_name(element_klass, CHECK_NULL);
123 
124   // Initialize instance variables
125   ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, null_free, CHECK_NULL);
126 
127   ModuleEntry* module = oak->module();
128   assert(module != nullptr, "No module entry for array");
129 
130   // Call complete_create_array_klass after all instance variables has been initialized.
131   ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_NULL);
132 
133   // Add all classes to our internal class loader list here,
134   // including classes in the bootstrap (null) class loader.
135   // Do this step after creating the mirror so that if the
136   // mirror creation fails, loaded_classes_do() doesn't find
137   // an array class without a mirror.
138   loader_data->add_class(oak);
139 
140   return oak;
141 }
142 
143 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name, bool null_free) : ArrayKlass(name, Kind) {
144   set_dimension(n);
145   set_element_klass(element_klass);
146 
147   Klass* bk;
148   if (element_klass->is_objArray_klass()) {
149     bk = ObjArrayKlass::cast(element_klass)->bottom_klass();
150   } else if (element_klass->is_flatArray_klass()) {
151     bk = FlatArrayKlass::cast(element_klass)->element_klass();
152   } else {
153     bk = element_klass;
154   }
155   assert(bk != nullptr && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass");
156   set_bottom_klass(bk);
157   set_class_loader_data(bk->class_loader_data());
158 
159   int lh = array_layout_helper(T_OBJECT);
160   if (null_free) {
161     assert(n == 1, "Bytecode does not support null-free multi-dim");
162     lh = layout_helper_set_null_free(lh);
163 #ifdef _LP64
164     set_prototype_header(markWord::null_free_array_prototype());
165     assert(prototype_header().is_null_free_array(), "sanity");
166 #else
167     set_prototype_header(markWord::inline_type_prototype());
168 #endif
169   }
170   set_layout_helper(lh);
171   assert(is_array_klass(), "sanity");
172   assert(is_objArray_klass(), "sanity");
173 }
174 
175 size_t ObjArrayKlass::oop_size(oop obj) const {
176   assert(obj->is_objArray(), "must be object array");
177   return objArrayOop(obj)->object_size();
178 }
179 
180 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) {
181   check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL);
182   size_t size = objArrayOopDesc::object_size(length);
183   bool populate_null_free = is_null_free_array_klass();
184   objArrayOop array =  (objArrayOop)Universe::heap()->array_allocate(this, size, length,
185                                                        /* do_zero */ true, CHECK_NULL);
186   objArrayHandle array_h(THREAD, array);
187   if (populate_null_free) {
188     assert(dimension() == 1, "Can only populate the final dimension");
189     assert(element_klass()->is_inline_klass(), "Unexpected");
190     assert(!element_klass()->is_array_klass(), "ArrayKlass unexpected here");
191     assert(!InlineKlass::cast(element_klass())->flat_array(), "Expected flatArrayOop allocation");
192     element_klass()->initialize(CHECK_NULL);
193     // Populate default values...
194     instanceOop value = (instanceOop) InlineKlass::cast(element_klass())->default_value();
195     for (int i = 0; i < length; i++) {
196       array_h->obj_at_put(i, value);
197     }
198   }
199   return array_h();
200 }
201 
202 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
203   int length = *sizes;
204   ArrayKlass* ld_klass = lower_dimension();
205   // If length < 0 allocate will throw an exception.
206   objArrayOop array = allocate(length, CHECK_NULL);
207   objArrayHandle h_array (THREAD, array);
208   if (rank > 1) {
209     if (length != 0) {
210       for (int index = 0; index < length; index++) {
211         oop sub_array = ld_klass->multi_allocate(rank-1, &sizes[1], CHECK_NULL);
212         h_array->obj_at_put(index, sub_array);
213       }
214     } else {
215       // Since this array dimension has zero length, nothing will be
216       // allocated, however the lower dimension values must be checked
217       // for illegal values.
218       for (int i = 0; i < rank - 1; ++i) {
219         sizes += 1;
220         if (*sizes < 0) {
221           THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes));
222         }
223       }
224     }
225   }
226   return h_array();
227 }
228 
229 // Either oop or narrowOop depending on UseCompressedOops.
230 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset,
231                             arrayOop d, size_t dst_offset, int length, TRAPS) {
232   if (s == d) {
233     // since source and destination are equal we do not need conversion checks.
234     assert(length > 0, "sanity check");
235     ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length);
236   } else {
237     // We have to make sure all elements conform to the destination array
238     Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
239     Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
240     // Perform null check if dst is null-free but src has no such guarantee
241     bool null_check = ((!s->klass()->is_null_free_array_klass()) &&
242         d->klass()->is_null_free_array_klass());
243     if (stype == bound || stype->is_subtype_of(bound)) {
244       if (null_check) {
245         ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_NOTNULL>::oop_arraycopy(s, src_offset, d, dst_offset, length);
246       } else {
247         ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length);
248       }
249     } else {
250       if (null_check) {
251         ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST | ARRAYCOPY_NOTNULL>::oop_arraycopy(s, src_offset, d, dst_offset, length);
252       } else {
253         ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length);
254       }
255     }
256   }
257 }
258 
259 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
260                                int dst_pos, int length, TRAPS) {
261   assert(s->is_objArray(), "must be obj array");
262 
263   if (UseFlatArray) {
264     if (d->is_flatArray()) {
265       FlatArrayKlass::cast(d->klass())->copy_array(s, src_pos, d, dst_pos, length, THREAD);
266       return;
267     }
268   }
269 
270   if (!d->is_objArray()) {
271     ResourceMark rm(THREAD);
272     stringStream ss;
273     if (d->is_typeArray()) {
274       ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]",
275                type2name_tab[ArrayKlass::cast(d->klass())->element_type()]);
276     } else {
277       ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name());
278     }
279     THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string());
280   }
281 
282   // Check is all offsets and lengths are non negative
283   if (src_pos < 0 || dst_pos < 0 || length < 0) {
284     // Pass specific exception reason.
285     ResourceMark rm(THREAD);
286     stringStream ss;
287     if (src_pos < 0) {
288       ss.print("arraycopy: source index %d out of bounds for object array[%d]",
289                src_pos, s->length());
290     } else if (dst_pos < 0) {
291       ss.print("arraycopy: destination index %d out of bounds for object array[%d]",
292                dst_pos, d->length());
293     } else {
294       ss.print("arraycopy: length %d is negative", length);
295     }
296     THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
297   }
298   // Check if the ranges are valid
299   if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) ||
300       (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) {
301     // Pass specific exception reason.
302     ResourceMark rm(THREAD);
303     stringStream ss;
304     if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) {
305       ss.print("arraycopy: last source index %u out of bounds for object array[%d]",
306                (unsigned int) length + (unsigned int) src_pos, s->length());
307     } else {
308       ss.print("arraycopy: last destination index %u out of bounds for object array[%d]",
309                (unsigned int) length + (unsigned int) dst_pos, d->length());
310     }
311     THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string());
312   }
313 
314   // Special case. Boundary cases must be checked first
315   // This allows the following call: copy_array(s, s.length(), d.length(), 0).
316   // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
317   // points to the right of the last element.
318   if (length==0) {
319     return;
320   }
321   if (UseCompressedOops) {
322     size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos);
323     size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos);
324     assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, nullptr) ==
325            objArrayOop(s)->obj_at_addr<narrowOop>(src_pos), "sanity");
326     assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, nullptr) ==
327            objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos), "sanity");
328     do_copy(s, src_offset, d, dst_offset, length, CHECK);
329   } else {
330     size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos);
331     size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos);
332     assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, nullptr) ==
333            objArrayOop(s)->obj_at_addr<oop>(src_pos), "sanity");
334     assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, nullptr) ==
335            objArrayOop(d)->obj_at_addr<oop>(dst_pos), "sanity");
336     do_copy(s, src_offset, d, dst_offset, length, CHECK);
337   }
338 }
339 
340 bool ObjArrayKlass::can_be_primary_super_slow() const {
341   if (!bottom_klass()->can_be_primary_super())
342     // array of interfaces
343     return false;
344   else
345     return Klass::can_be_primary_super_slow();
346 }
347 
348 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots,
349                                                                Array<InstanceKlass*>* transitive_interfaces) {
350   assert(transitive_interfaces == nullptr, "sanity");
351   // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
352   const Array<Klass*>* elem_supers = element_klass()->secondary_supers();
353   int num_elem_supers = elem_supers == nullptr ? 0 : elem_supers->length();
354   int num_secondaries = num_extra_slots + 2 + num_elem_supers;
355   if (num_secondaries == 2) {
356     // Must share this for correct bootstrapping!
357     set_secondary_supers(Universe::the_array_interfaces_array());
358     return nullptr;
359   } else {
360     GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
361     secondaries->push(vmClasses::Cloneable_klass());
362     secondaries->push(vmClasses::Serializable_klass());
363     for (int i = 0; i < num_elem_supers; i++) {
364       Klass* elem_super = elem_supers->at(i);
365       Klass* array_super = elem_super->array_klass_or_null();
366       assert(array_super != nullptr, "must already have been created");
367       secondaries->push(array_super);
368     }
369     return secondaries;
370   }
371 }
372 
373 void ObjArrayKlass::initialize(TRAPS) {
374   bottom_klass()->initialize(THREAD);  // dispatches to either InstanceKlass or TypeArrayKlass
375 }
376 
377 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
378   ArrayKlass::metaspace_pointers_do(it);
379   it->push(&_element_klass);
380   it->push(&_bottom_klass);
381 }
382 
383 jint ObjArrayKlass::compute_modifier_flags() const {
384   // The modifier for an objectArray is the same as its element
385   if (element_klass() == nullptr) {
386     assert(Universe::is_bootstrapping(), "partial objArray only at startup");
387     return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
388   }
389   // Return the flags of the bottom element type.
390   jint element_flags = bottom_klass()->compute_modifier_flags();
391 
392   return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
393                         | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
394 }
395 
396 ModuleEntry* ObjArrayKlass::module() const {
397   assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
398   // The array is defined in the module of its bottom class
399   return bottom_klass()->module();
400 }
401 
402 PackageEntry* ObjArrayKlass::package() const {
403   assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass");
404   return bottom_klass()->package();
405 }
406 
407 // Printing
408 
409 void ObjArrayKlass::print_on(outputStream* st) const {
410 #ifndef PRODUCT
411   Klass::print_on(st);
412   st->print(" - element klass: ");
413   element_klass()->print_value_on(st);
414   st->cr();
415 #endif //PRODUCT
416 }
417 
418 void ObjArrayKlass::print_value_on(outputStream* st) const {
419   assert(is_klass(), "must be klass");
420 
421   element_klass()->print_value_on(st);
422   st->print("[]");
423 }
424 
425 #ifndef PRODUCT
426 
427 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
428   ArrayKlass::oop_print_on(obj, st);
429   assert(obj->is_objArray(), "must be objArray");
430   objArrayOop oa = objArrayOop(obj);
431   int print_len = MIN2(oa->length(), MaxElementPrintSize);
432   for(int index = 0; index < print_len; index++) {
433     st->print(" - %3d : ", index);
434     if (oa->obj_at(index) != nullptr) {
435       oa->obj_at(index)->print_value_on(st);
436       st->cr();
437     } else {
438       st->print_cr("null");
439     }
440   }
441   int remaining = oa->length() - print_len;
442   if (remaining > 0) {
443     st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
444   }
445 }
446 
447 #endif //PRODUCT
448 
449 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
450   assert(obj->is_objArray(), "must be objArray");
451   st->print("a ");
452   element_klass()->print_value_on(st);
453   int len = objArrayOop(obj)->length();
454   st->print("[%d] ", len);
455   if (obj != nullptr) {
456     obj->print_address_on(st);
457   } else {
458     st->print_cr("null");
459   }
460 }
461 
462 const char* ObjArrayKlass::internal_name() const {
463   return external_name();
464 }
465 
466 
467 // Verification
468 
469 void ObjArrayKlass::verify_on(outputStream* st) {
470   ArrayKlass::verify_on(st);
471   guarantee(element_klass()->is_klass(), "should be klass");
472   guarantee(bottom_klass()->is_klass(), "should be klass");
473   Klass* bk = bottom_klass();
474   guarantee(bk->is_instance_klass() || bk->is_typeArray_klass() || bk->is_flatArray_klass(),
475             "invalid bottom klass");
476 }
477 
478 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
479   ArrayKlass::oop_verify_on(obj, st);
480   guarantee(obj->is_objArray(), "must be objArray");
481   guarantee(obj->is_null_free_array() || (!is_null_free_array_klass()), "null-free klass but not object");
482   objArrayOop oa = objArrayOop(obj);
483   for(int index = 0; index < oa->length(); index++) {
484     guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop");
485   }
486 }