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(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 ObjArrayKlass* ObjArrayKlass::allocate_objArray_klass(ClassLoaderData* loader_data, 57 int n, Klass* element_klass, TRAPS) { 58 59 // Eagerly allocate the direct array supertype. 60 Klass* super_klass = nullptr; 61 if (!Universe::is_bootstrapping() || vmClasses::Object_klass_loaded()) { 62 assert(MultiArray_lock->holds_lock(THREAD), "must hold lock after bootstrapping"); 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 // Also, see if the element has secondary supertypes. 67 // We need an array type for each before creating this array type. 68 super_klass = element_super->array_klass(CHECK_NULL); 69 const Array<Klass*>* element_supers = element_klass->secondary_supers(); 70 for (int i = element_supers->length() - 1; i >= 0; i--) { 71 Klass* elem_super = element_supers->at(i); 72 elem_super->array_klass(CHECK_NULL); 73 } 74 // Fall through because inheritance is acyclic and we hold the global recursive lock to allocate all the arrays. 75 } else { 76 // The element type is already Object. Object[] has direct super of Object. 77 super_klass = vmClasses::Object_klass(); 78 } 79 } 80 81 // Create type name for klass. 82 Symbol* name = nullptr; 83 { 84 ResourceMark rm(THREAD); 85 char *name_str = element_klass->name()->as_C_string(); 86 int len = element_klass->name()->utf8_length(); 87 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4); 88 int idx = 0; 89 new_str[idx++] = JVM_SIGNATURE_ARRAY; 90 if (element_klass->is_instance_klass()) { // it could be an array or simple type 91 new_str[idx++] = JVM_SIGNATURE_CLASS; 92 } 93 memcpy(&new_str[idx], name_str, len * sizeof(char)); 94 idx += len; 95 if (element_klass->is_instance_klass()) { 96 new_str[idx++] = JVM_SIGNATURE_ENDCLASS; 97 } 98 new_str[idx++] = '\0'; 99 name = SymbolTable::new_symbol(new_str); 100 } 101 102 // Initialize instance variables 103 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_NULL); 104 105 ModuleEntry* module = oak->module(); 106 assert(module != nullptr, "No module entry for array"); 107 108 // Call complete_create_array_klass after all instance variables has been initialized. 109 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_NULL); 110 111 // Add all classes to our internal class loader list here, 112 // including classes in the bootstrap (null) class loader. 113 // Do this step after creating the mirror so that if the 114 // mirror creation fails, loaded_classes_do() doesn't find 115 // an array class without a mirror. 116 loader_data->add_class(oak); 117 118 return oak; 119 } 120 121 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name) : ArrayKlass(name, Kind) { 122 set_dimension(n); 123 set_element_klass(element_klass); 124 125 Klass* bk; 126 if (element_klass->is_objArray_klass()) { 127 bk = ObjArrayKlass::cast(element_klass)->bottom_klass(); 128 } else { 129 bk = element_klass; 130 } 131 assert(bk != nullptr && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass"); 132 set_bottom_klass(bk); 133 set_class_loader_data(bk->class_loader_data()); 134 135 if (element_klass->is_array_klass()) { 136 set_lower_dimension(ArrayKlass::cast(element_klass)); 137 } 138 139 set_layout_helper(array_layout_helper(T_OBJECT)); 140 assert(is_array_klass(), "sanity"); 141 assert(is_objArray_klass(), "sanity"); 142 143 // Compute modifier flags after bottom_klass and element_klass are initialized. 144 set_modifier_flags(compute_modifier_flags()); 145 } 146 147 size_t ObjArrayKlass::oop_size(oop obj) const { 148 // In this assert, we cannot safely access the Klass* with compact headers, 149 // because size_given_klass() calls oop_size() on objects that might be 150 // concurrently forwarded, which would overwrite the Klass*. 151 assert(UseCompactObjectHeaders || obj->is_objArray(), "must be object array"); 152 return objArrayOop(obj)->object_size(); 153 } 154 155 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) { 156 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL); 157 size_t size = objArrayOopDesc::object_size(length); 158 return (objArrayOop)Universe::heap()->array_allocate(this, size, length, 159 /* do_zero */ true, THREAD); 160 } 161 162 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 163 int length = *sizes; 164 ArrayKlass* ld_klass = lower_dimension(); 165 // If length < 0 allocate will throw an exception. 166 objArrayOop array = allocate(length, CHECK_NULL); 167 objArrayHandle h_array (THREAD, array); 168 if (rank > 1) { 169 if (length != 0) { 170 for (int index = 0; index < length; index++) { 171 oop sub_array = ld_klass->multi_allocate(rank - 1, &sizes[1], CHECK_NULL); 172 h_array->obj_at_put(index, sub_array); 173 } 174 } else { 175 // Since this array dimension has zero length, nothing will be 176 // allocated, however the lower dimension values must be checked 177 // for illegal values. 178 for (int i = 0; i < rank - 1; ++i) { 179 sizes += 1; 180 if (*sizes < 0) { 181 THROW_MSG_NULL(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes)); 182 } 183 } 184 } 185 } 186 return h_array(); 187 } 188 189 // Either oop or narrowOop depending on UseCompressedOops. 190 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset, 191 arrayOop d, size_t dst_offset, int length, TRAPS) { 192 if (s == d) { 193 // since source and destination are equal we do not need conversion checks. 194 assert(length > 0, "sanity check"); 195 ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length); 196 } else { 197 // We have to make sure all elements conform to the destination array 198 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass(); 199 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass(); 200 if (stype == bound || stype->is_subtype_of(bound)) { 201 // elements are guaranteed to be subtypes, so no check necessary 202 ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length); 203 } else { 204 // slow case: need individual subtype checks 205 // note: don't use obj_at_put below because it includes a redundant store check 206 if (!ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length)) { 207 ResourceMark rm(THREAD); 208 stringStream ss; 209 if (!bound->is_subtype_of(stype)) { 210 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]", 211 stype->external_name(), bound->external_name()); 212 } else { 213 // oop_arraycopy should return the index in the source array that 214 // contains the problematic oop. 215 ss.print("arraycopy: element type mismatch: can not cast one of the elements" 216 " of %s[] to the type of the destination array, %s", 217 stype->external_name(), bound->external_name()); 218 } 219 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string()); 220 } 221 } 222 } 223 } 224 225 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d, 226 int dst_pos, int length, TRAPS) { 227 assert(s->is_objArray(), "must be obj array"); 228 229 if (!d->is_objArray()) { 230 ResourceMark rm(THREAD); 231 stringStream ss; 232 if (d->is_typeArray()) { 233 ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]", 234 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]); 235 } else { 236 ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name()); 237 } 238 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string()); 239 } 240 241 // Check is all offsets and lengths are non negative 242 if (src_pos < 0 || dst_pos < 0 || length < 0) { 243 // Pass specific exception reason. 244 ResourceMark rm(THREAD); 245 stringStream ss; 246 if (src_pos < 0) { 247 ss.print("arraycopy: source index %d out of bounds for object array[%d]", 248 src_pos, s->length()); 249 } else if (dst_pos < 0) { 250 ss.print("arraycopy: destination index %d out of bounds for object array[%d]", 251 dst_pos, d->length()); 252 } else { 253 ss.print("arraycopy: length %d is negative", length); 254 } 255 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string()); 256 } 257 // Check if the ranges are valid 258 if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) || 259 (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) { 260 // Pass specific exception reason. 261 ResourceMark rm(THREAD); 262 stringStream ss; 263 if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) { 264 ss.print("arraycopy: last source index %u out of bounds for object array[%d]", 265 (unsigned int) length + (unsigned int) src_pos, s->length()); 266 } else { 267 ss.print("arraycopy: last destination index %u out of bounds for object array[%d]", 268 (unsigned int) length + (unsigned int) dst_pos, d->length()); 269 } 270 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string()); 271 } 272 273 // Special case. Boundary cases must be checked first 274 // This allows the following call: copy_array(s, s.length(), d.length(), 0). 275 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(), 276 // points to the right of the last element. 277 if (length==0) { 278 return; 279 } 280 if (UseCompressedOops) { 281 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos); 282 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos); 283 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, nullptr) == 284 objArrayOop(s)->obj_at_addr<narrowOop>(src_pos), "sanity"); 285 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, nullptr) == 286 objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos), "sanity"); 287 do_copy(s, src_offset, d, dst_offset, length, CHECK); 288 } else { 289 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos); 290 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos); 291 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, nullptr) == 292 objArrayOop(s)->obj_at_addr<oop>(src_pos), "sanity"); 293 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, nullptr) == 294 objArrayOop(d)->obj_at_addr<oop>(dst_pos), "sanity"); 295 do_copy(s, src_offset, d, dst_offset, length, CHECK); 296 } 297 } 298 299 bool ObjArrayKlass::can_be_primary_super_slow() const { 300 if (!bottom_klass()->can_be_primary_super()) 301 // array of interfaces 302 return false; 303 else 304 return Klass::can_be_primary_super_slow(); 305 } 306 307 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots, 308 Array<InstanceKlass*>* transitive_interfaces) { 309 assert(transitive_interfaces == nullptr, "sanity"); 310 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... }; 311 const Array<Klass*>* elem_supers = element_klass()->secondary_supers(); 312 int num_elem_supers = elem_supers == nullptr ? 0 : elem_supers->length(); 313 int num_secondaries = num_extra_slots + 2 + num_elem_supers; 314 if (num_secondaries == 2) { 315 // Must share this for correct bootstrapping! 316 set_secondary_supers(Universe::the_array_interfaces_array(), 317 Universe::the_array_interfaces_bitmap()); 318 return nullptr; 319 } else { 320 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2); 321 secondaries->push(vmClasses::Cloneable_klass()); 322 secondaries->push(vmClasses::Serializable_klass()); 323 for (int i = 0; i < num_elem_supers; i++) { 324 Klass* elem_super = elem_supers->at(i); 325 Klass* array_super = elem_super->array_klass_or_null(); 326 assert(array_super != nullptr, "must already have been created"); 327 secondaries->push(array_super); 328 } 329 return secondaries; 330 } 331 } 332 333 void ObjArrayKlass::initialize(TRAPS) { 334 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass 335 } 336 337 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) { 338 ArrayKlass::metaspace_pointers_do(it); 339 it->push(&_element_klass); 340 it->push(&_bottom_klass); 341 } 342 343 u2 ObjArrayKlass::compute_modifier_flags() const { 344 // The modifier for an objectArray is the same as its element 345 assert (element_klass() != nullptr, "should be initialized"); 346 347 // Return the flags of the bottom element type. 348 u2 element_flags = bottom_klass()->compute_modifier_flags(); 349 350 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED)) 351 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL); 352 } 353 354 ModuleEntry* ObjArrayKlass::module() const { 355 assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass"); 356 // The array is defined in the module of its bottom class 357 return bottom_klass()->module(); 358 } 359 360 PackageEntry* ObjArrayKlass::package() const { 361 assert(bottom_klass() != nullptr, "ObjArrayKlass returned unexpected null bottom_klass"); 362 return bottom_klass()->package(); 363 } 364 365 // Printing 366 367 void ObjArrayKlass::print_on(outputStream* st) const { 368 #ifndef PRODUCT 369 Klass::print_on(st); 370 st->print(" - instance klass: "); 371 element_klass()->print_value_on(st); 372 st->cr(); 373 #endif //PRODUCT 374 } 375 376 void ObjArrayKlass::print_value_on(outputStream* st) const { 377 assert(is_klass(), "must be klass"); 378 379 element_klass()->print_value_on(st); 380 st->print("[]"); 381 } 382 383 #ifndef PRODUCT 384 385 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) { 386 ArrayKlass::oop_print_on(obj, st); 387 assert(obj->is_objArray(), "must be objArray"); 388 objArrayOop oa = objArrayOop(obj); 389 int print_len = MIN2(oa->length(), MaxElementPrintSize); 390 for(int index = 0; index < print_len; index++) { 391 st->print(" - %3d : ", index); 392 if (oa->obj_at(index) != nullptr) { 393 oa->obj_at(index)->print_value_on(st); 394 st->cr(); 395 } else { 396 st->print_cr("null"); 397 } 398 } 399 int remaining = oa->length() - print_len; 400 if (remaining > 0) { 401 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining); 402 } 403 } 404 405 #endif //PRODUCT 406 407 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) { 408 assert(obj->is_objArray(), "must be objArray"); 409 st->print("a "); 410 element_klass()->print_value_on(st); 411 int len = objArrayOop(obj)->length(); 412 st->print("[%d] ", len); 413 if (obj != nullptr) { 414 obj->print_address_on(st); 415 } else { 416 st->print_cr("null"); 417 } 418 } 419 420 const char* ObjArrayKlass::internal_name() const { 421 return external_name(); 422 } 423 424 425 // Verification 426 427 void ObjArrayKlass::verify_on(outputStream* st) { 428 ArrayKlass::verify_on(st); 429 guarantee(element_klass()->is_klass(), "should be klass"); 430 guarantee(bottom_klass()->is_klass(), "should be klass"); 431 Klass* bk = bottom_klass(); 432 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(), "invalid bottom klass"); 433 } 434 435 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) { 436 ArrayKlass::oop_verify_on(obj, st); 437 guarantee(obj->is_objArray(), "must be objArray"); 438 objArrayOop oa = objArrayOop(obj); 439 for(int index = 0; index < oa->length(); index++) { 440 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop"); 441 } 442 }