1 /* 2 * Copyright (c) 1997, 2020, 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/systemDictionary.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.inline.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 Klass* 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 = NULL; 62 if (!Universe::is_bootstrapping() || SystemDictionary::Object_klass_loaded()) { 63 Klass* element_super = element_klass->super(); 64 if (element_super != NULL) { 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 != NULL; 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() == NULL) { 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 = NULL; 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 ek; 92 } 93 } else { 94 // The element type is already Object. Object[] has direct super of Object. 95 super_klass = SystemDictionary::Object_klass(); 96 } 97 } 98 99 // Create type name for klass. 100 Symbol* name = NULL; 101 if (!element_klass->is_instance_klass() || 102 (name = InstanceKlass::cast(element_klass)->array_name()) == NULL) { 103 104 ResourceMark rm(THREAD); 105 char *name_str = element_klass->name()->as_C_string(); 106 int len = element_klass->name()->utf8_length(); 107 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4); 108 int idx = 0; 109 new_str[idx++] = JVM_SIGNATURE_ARRAY; 110 if (element_klass->is_instance_klass()) { // it could be an array or simple type 111 new_str[idx++] = JVM_SIGNATURE_CLASS; 112 } 113 memcpy(&new_str[idx], name_str, len * sizeof(char)); 114 idx += len; 115 if (element_klass->is_instance_klass()) { 116 new_str[idx++] = JVM_SIGNATURE_ENDCLASS; 117 } 118 new_str[idx++] = '\0'; 119 name = SymbolTable::new_permanent_symbol(new_str); 120 if (element_klass->is_instance_klass()) { 121 InstanceKlass* ik = InstanceKlass::cast(element_klass); 122 ik->set_array_name(name); 123 } 124 } 125 126 // Initialize instance variables 127 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_NULL); 128 129 ModuleEntry* module = oak->module(); 130 assert(module != NULL, "No module entry for array"); 131 132 // Call complete_create_array_klass after all instance variables has been initialized. 133 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_NULL); 134 135 // Add all classes to our internal class loader list here, 136 // including classes in the bootstrap (NULL) class loader. 137 // Do this step after creating the mirror so that if the 138 // mirror creation fails, loaded_classes_do() doesn't find 139 // an array class without a mirror. 140 loader_data->add_class(oak); 141 142 return oak; 143 } 144 145 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name) : ArrayKlass(name, ID) { 146 this->set_dimension(n); 147 this->set_element_klass(element_klass); 148 // decrement refcount because object arrays are not explicitly freed. The 149 // InstanceKlass array_name() keeps the name counted while the klass is 150 // loaded. 151 name->decrement_refcount(); 152 153 Klass* bk; 154 if (element_klass->is_objArray_klass()) { 155 bk = ObjArrayKlass::cast(element_klass)->bottom_klass(); 156 } else { 157 bk = element_klass; 158 } 159 assert(bk != NULL && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass"); 160 this->set_bottom_klass(bk); 161 this->set_class_loader_data(bk->class_loader_data()); 162 163 this->set_layout_helper(array_layout_helper(T_OBJECT)); 164 assert(this->is_array_klass(), "sanity"); 165 assert(this->is_objArray_klass(), "sanity"); 166 } 167 168 int ObjArrayKlass::oop_size(oop obj) const { 169 assert(obj->is_objArray(), "must be object array"); 170 return objArrayOop(obj)->object_size(); 171 } 172 173 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) { 174 check_array_allocation_length(length, arrayOopDesc::max_array_length(T_OBJECT), CHECK_NULL); 175 int size = objArrayOopDesc::object_size(length); 176 return (objArrayOop)Universe::heap()->array_allocate(this, size, length, 177 /* do_zero */ true, THREAD); 178 } 179 180 static int multi_alloc_counter = 0; 181 182 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 183 int length = *sizes; 184 // Call to lower_dimension uses this pointer, so most be called before a 185 // possible GC 186 Klass* ld_klass = lower_dimension(); 187 // If length < 0 allocate will throw an exception. 188 objArrayOop array = allocate(length, CHECK_NULL); 189 objArrayHandle h_array (THREAD, array); 190 if (rank > 1) { 191 if (length != 0) { 192 for (int index = 0; index < length; index++) { 193 ArrayKlass* ak = ArrayKlass::cast(ld_klass); 194 oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL); 195 h_array->obj_at_put(index, sub_array); 196 } 197 } else { 198 // Since this array dimension has zero length, nothing will be 199 // allocated, however the lower dimension values must be checked 200 // for illegal values. 201 for (int i = 0; i < rank - 1; ++i) { 202 sizes += 1; 203 if (*sizes < 0) { 204 THROW_MSG_0(vmSymbols::java_lang_NegativeArraySizeException(), err_msg("%d", *sizes)); 205 } 206 } 207 } 208 } 209 return h_array(); 210 } 211 212 // Either oop or narrowOop depending on UseCompressedOops. 213 void ObjArrayKlass::do_copy(arrayOop s, size_t src_offset, 214 arrayOop d, size_t dst_offset, int length, TRAPS) { 215 if (s == d) { 216 // since source and destination are equal we do not need conversion checks. 217 assert(length > 0, "sanity check"); 218 ArrayAccess<>::oop_arraycopy(s, src_offset, d, dst_offset, length); 219 } else { 220 // We have to make sure all elements conform to the destination array 221 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass(); 222 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass(); 223 if (stype == bound || stype->is_subtype_of(bound)) { 224 // elements are guaranteed to be subtypes, so no check necessary 225 ArrayAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, src_offset, d, dst_offset, length); 226 } else { 227 // slow case: need individual subtype checks 228 // note: don't use obj_at_put below because it includes a redundant store check 229 if (!ArrayAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, src_offset, d, dst_offset, length)) { 230 ResourceMark rm(THREAD); 231 stringStream ss; 232 if (!bound->is_subtype_of(stype)) { 233 ss.print("arraycopy: type mismatch: can not copy %s[] into %s[]", 234 stype->external_name(), bound->external_name()); 235 } else { 236 // oop_arraycopy should return the index in the source array that 237 // contains the problematic oop. 238 ss.print("arraycopy: element type mismatch: can not cast one of the elements" 239 " of %s[] to the type of the destination array, %s", 240 stype->external_name(), bound->external_name()); 241 } 242 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string()); 243 } 244 } 245 } 246 } 247 248 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d, 249 int dst_pos, int length, TRAPS) { 250 assert(s->is_objArray(), "must be obj array"); 251 252 if (!d->is_objArray()) { 253 ResourceMark rm(THREAD); 254 stringStream ss; 255 if (d->is_typeArray()) { 256 ss.print("arraycopy: type mismatch: can not copy object array[] into %s[]", 257 type2name_tab[ArrayKlass::cast(d->klass())->element_type()]); 258 } else { 259 ss.print("arraycopy: destination type %s is not an array", d->klass()->external_name()); 260 } 261 THROW_MSG(vmSymbols::java_lang_ArrayStoreException(), ss.as_string()); 262 } 263 264 // Check is all offsets and lengths are non negative 265 if (src_pos < 0 || dst_pos < 0 || length < 0) { 266 // Pass specific exception reason. 267 ResourceMark rm(THREAD); 268 stringStream ss; 269 if (src_pos < 0) { 270 ss.print("arraycopy: source index %d out of bounds for object array[%d]", 271 src_pos, s->length()); 272 } else if (dst_pos < 0) { 273 ss.print("arraycopy: destination index %d out of bounds for object array[%d]", 274 dst_pos, d->length()); 275 } else { 276 ss.print("arraycopy: length %d is negative", length); 277 } 278 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string()); 279 } 280 // Check if the ranges are valid 281 if ((((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) || 282 (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length())) { 283 // Pass specific exception reason. 284 ResourceMark rm(THREAD); 285 stringStream ss; 286 if (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) { 287 ss.print("arraycopy: last source index %u out of bounds for object array[%d]", 288 (unsigned int) length + (unsigned int) src_pos, s->length()); 289 } else { 290 ss.print("arraycopy: last destination index %u out of bounds for object array[%d]", 291 (unsigned int) length + (unsigned int) dst_pos, d->length()); 292 } 293 THROW_MSG(vmSymbols::java_lang_ArrayIndexOutOfBoundsException(), ss.as_string()); 294 } 295 296 // Special case. Boundary cases must be checked first 297 // This allows the following call: copy_array(s, s.length(), d.length(), 0). 298 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(), 299 // points to the right of the last element. 300 if (length==0) { 301 return; 302 } 303 if (UseCompressedOops) { 304 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(src_pos); 305 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<narrowOop>(dst_pos); 306 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(s, src_offset, NULL) == 307 objArrayOop(s)->obj_at_addr_raw<narrowOop>(src_pos), "sanity"); 308 assert(arrayOopDesc::obj_offset_to_raw<narrowOop>(d, dst_offset, NULL) == 309 objArrayOop(d)->obj_at_addr_raw<narrowOop>(dst_pos), "sanity"); 310 do_copy(s, src_offset, d, dst_offset, length, CHECK); 311 } else { 312 size_t src_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(src_pos); 313 size_t dst_offset = (size_t) objArrayOopDesc::obj_at_offset<oop>(dst_pos); 314 assert(arrayOopDesc::obj_offset_to_raw<oop>(s, src_offset, NULL) == 315 objArrayOop(s)->obj_at_addr_raw<oop>(src_pos), "sanity"); 316 assert(arrayOopDesc::obj_offset_to_raw<oop>(d, dst_offset, NULL) == 317 objArrayOop(d)->obj_at_addr_raw<oop>(dst_pos), "sanity"); 318 do_copy(s, src_offset, d, dst_offset, length, CHECK); 319 } 320 } 321 322 323 Klass* ObjArrayKlass::array_klass_impl(bool or_null, int n, TRAPS) { 324 325 assert(dimension() <= n, "check order of chain"); 326 int dim = dimension(); 327 if (dim == n) return this; 328 329 // lock-free read needs acquire semantics 330 if (higher_dimension_acquire() == NULL) { 331 if (or_null) return NULL; 332 333 ResourceMark rm; 334 JavaThread *jt = (JavaThread *)THREAD; 335 { 336 // Ensure atomic creation of higher dimensions 337 MutexLocker mu(THREAD, MultiArray_lock); 338 339 // Check if another thread beat us 340 if (higher_dimension() == NULL) { 341 342 // Create multi-dim klass object and link them together 343 Klass* k = 344 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL); 345 ObjArrayKlass* ak = ObjArrayKlass::cast(k); 346 ak->set_lower_dimension(this); 347 // use 'release' to pair with lock-free load 348 release_set_higher_dimension(ak); 349 assert(ak->is_objArray_klass(), "incorrect initialization of ObjArrayKlass"); 350 } 351 } 352 } 353 354 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension()); 355 if (or_null) { 356 return ak->array_klass_or_null(n); 357 } 358 THREAD->check_possible_safepoint(); 359 return ak->array_klass(n, THREAD); 360 } 361 362 Klass* ObjArrayKlass::array_klass_impl(bool or_null, TRAPS) { 363 return array_klass_impl(or_null, dimension() + 1, THREAD); 364 } 365 366 bool ObjArrayKlass::can_be_primary_super_slow() const { 367 if (!bottom_klass()->can_be_primary_super()) 368 // array of interfaces 369 return false; 370 else 371 return Klass::can_be_primary_super_slow(); 372 } 373 374 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots, 375 Array<InstanceKlass*>* transitive_interfaces) { 376 assert(transitive_interfaces == NULL, "sanity"); 377 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... }; 378 const Array<Klass*>* elem_supers = element_klass()->secondary_supers(); 379 int num_elem_supers = elem_supers == NULL ? 0 : elem_supers->length(); 380 int num_secondaries = num_extra_slots + 2 + num_elem_supers; 381 if (num_secondaries == 2) { 382 // Must share this for correct bootstrapping! 383 set_secondary_supers(Universe::the_array_interfaces_array()); 384 return NULL; 385 } else { 386 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2); 387 secondaries->push(SystemDictionary::Cloneable_klass()); 388 secondaries->push(SystemDictionary::Serializable_klass()); 389 for (int i = 0; i < num_elem_supers; i++) { 390 Klass* elem_super = elem_supers->at(i); 391 Klass* array_super = elem_super->array_klass_or_null(); 392 assert(array_super != NULL, "must already have been created"); 393 secondaries->push(array_super); 394 } 395 return secondaries; 396 } 397 } 398 399 void ObjArrayKlass::initialize(TRAPS) { 400 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass 401 } 402 403 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) { 404 ArrayKlass::metaspace_pointers_do(it); 405 it->push(&_element_klass); 406 it->push(&_bottom_klass); 407 } 408 409 // JVM support 410 411 jint ObjArrayKlass::compute_modifier_flags(TRAPS) const { 412 // The modifier for an objectArray is the same as its element 413 if (element_klass() == NULL) { 414 assert(Universe::is_bootstrapping(), "partial objArray only at startup"); 415 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 416 } 417 // Return the flags of the bottom element type. 418 jint element_flags = bottom_klass()->compute_modifier_flags(CHECK_0); 419 420 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED)) 421 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL); 422 } 423 424 ModuleEntry* ObjArrayKlass::module() const { 425 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass"); 426 // The array is defined in the module of its bottom class 427 return bottom_klass()->module(); 428 } 429 430 PackageEntry* ObjArrayKlass::package() const { 431 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass"); 432 return bottom_klass()->package(); 433 } 434 435 // Printing 436 437 void ObjArrayKlass::print_on(outputStream* st) const { 438 #ifndef PRODUCT 439 Klass::print_on(st); 440 st->print(" - instance klass: "); 441 element_klass()->print_value_on(st); 442 st->cr(); 443 #endif //PRODUCT 444 } 445 446 void ObjArrayKlass::print_value_on(outputStream* st) const { 447 assert(is_klass(), "must be klass"); 448 449 element_klass()->print_value_on(st); 450 st->print("[]"); 451 } 452 453 #ifndef PRODUCT 454 455 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) { 456 ArrayKlass::oop_print_on(obj, st); 457 assert(obj->is_objArray(), "must be objArray"); 458 objArrayOop oa = objArrayOop(obj); 459 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize); 460 for(int index = 0; index < print_len; index++) { 461 st->print(" - %3d : ", index); 462 if (oa->obj_at(index) != NULL) { 463 oa->obj_at(index)->print_value_on(st); 464 st->cr(); 465 } else { 466 st->print_cr("NULL"); 467 } 468 } 469 int remaining = oa->length() - print_len; 470 if (remaining > 0) { 471 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining); 472 } 473 } 474 475 #endif //PRODUCT 476 477 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) { 478 assert(obj->is_objArray(), "must be objArray"); 479 st->print("a "); 480 element_klass()->print_value_on(st); 481 int len = objArrayOop(obj)->length(); 482 st->print("[%d] ", len); 483 if (obj != NULL) { 484 obj->print_address_on(st); 485 } else { 486 st->print_cr("NULL"); 487 } 488 } 489 490 const char* ObjArrayKlass::internal_name() const { 491 return external_name(); 492 } 493 494 495 // Verification 496 497 void ObjArrayKlass::verify_on(outputStream* st) { 498 ArrayKlass::verify_on(st); 499 guarantee(element_klass()->is_klass(), "should be klass"); 500 guarantee(bottom_klass()->is_klass(), "should be klass"); 501 Klass* bk = bottom_klass(); 502 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(), "invalid bottom klass"); 503 } 504 505 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) { 506 ArrayKlass::oop_verify_on(obj, st); 507 guarantee(obj->is_objArray(), "must be objArray"); 508 objArrayOop oa = objArrayOop(obj); 509 for(int index = 0; index < oa->length(); index++) { 510 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop"); 511 } 512 }