1 /* 2 * Copyright (c) 1997, 2017, 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 "gc/shared/specialized_oop_closures.hpp" 33 #include "memory/iterator.inline.hpp" 34 #include "memory/metadataFactory.hpp" 35 #include "memory/resourceArea.hpp" 36 #include "memory/universe.inline.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/copy.hpp" 47 #include "utilities/macros.hpp" 48 49 ObjArrayKlass* ObjArrayKlass::allocate(ClassLoaderData* loader_data, int n, Klass* k, Symbol* name, TRAPS) { 50 assert(ObjArrayKlass::header_size() <= InstanceKlass::header_size(), 51 "array klasses must be same size as InstanceKlass"); 52 53 int size = ArrayKlass::static_size(ObjArrayKlass::header_size()); 54 55 return new (loader_data, size, THREAD) ObjArrayKlass(n, k, name); 56 } 57 58 Klass* ObjArrayKlass::allocate_objArray_klass(ClassLoaderData* loader_data, 59 int n, Klass* element_klass, TRAPS) { 60 61 // Eagerly allocate the direct array supertype. 62 Klass* super_klass = NULL; 63 if (!Universe::is_bootstrapping() || SystemDictionary::Object_klass_loaded()) { 64 Klass* element_super = element_klass->super(); 65 if (element_super != NULL) { 66 // The element type has a direct super. E.g., String[] has direct super of Object[]. 67 super_klass = element_super->array_klass_or_null(); 68 bool supers_exist = super_klass != NULL; 69 // Also, see if the element has secondary supertypes. 70 // We need an array type for each. 71 Array<Klass*>* element_supers = element_klass->secondary_supers(); 72 for( int i = element_supers->length()-1; i >= 0; i-- ) { 73 Klass* elem_super = element_supers->at(i); 74 if (elem_super->array_klass_or_null() == NULL) { 75 supers_exist = false; 76 break; 77 } 78 } 79 if (!supers_exist) { 80 // Oops. Not allocated yet. Back out, allocate it, and retry. 81 Klass* ek = NULL; 82 { 83 MutexUnlocker mu(MultiArray_lock); 84 MutexUnlocker mc(Compile_lock); // for vtables 85 super_klass = element_super->array_klass(CHECK_0); 86 for( int i = element_supers->length()-1; i >= 0; i-- ) { 87 Klass* elem_super = element_supers->at(i); 88 elem_super->array_klass(CHECK_0); 89 } 90 // Now retry from the beginning 91 ek = element_klass->array_klass(n, CHECK_0); 92 } // re-lock 93 return ek; 94 } 95 } else { 96 // The element type is already Object. Object[] has direct super of Object. 97 super_klass = SystemDictionary::Object_klass(); 98 } 99 } 100 101 // Create type name for klass. 102 Symbol* name = NULL; 103 if (!element_klass->is_instance_klass() || 104 (name = InstanceKlass::cast(element_klass)->array_name()) == NULL) { 105 106 ResourceMark rm(THREAD); 107 char *name_str = element_klass->name()->as_C_string(); 108 int len = element_klass->name()->utf8_length(); 109 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4); 110 int idx = 0; 111 new_str[idx++] = '['; 112 if (element_klass->is_instance_klass()) { // it could be an array or simple type 113 new_str[idx++] = 'L'; 114 } 115 memcpy(&new_str[idx], name_str, len * sizeof(char)); 116 idx += len; 117 if (element_klass->is_instance_klass()) { 118 new_str[idx++] = ';'; 119 } 120 new_str[idx++] = '\0'; 121 name = SymbolTable::new_permanent_symbol(new_str, CHECK_0); 122 if (element_klass->is_instance_klass()) { 123 InstanceKlass* ik = InstanceKlass::cast(element_klass); 124 ik->set_array_name(name); 125 } 126 } 127 128 // Initialize instance variables 129 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_0); 130 131 // Add all classes to our internal class loader list here, 132 // including classes in the bootstrap (NULL) class loader. 133 // GC walks these as strong roots. 134 loader_data->add_class(oak); 135 136 ModuleEntry* module = oak->module(); 137 assert(module != NULL, "No module entry for array"); 138 139 // Call complete_create_array_klass after all instance variables has been initialized. 140 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_0); 141 142 return oak; 143 } 144 145 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name) : ArrayKlass(name) { 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 if (length >= 0) { 175 if (length <= arrayOopDesc::max_array_length(T_OBJECT)) { 176 int size = objArrayOopDesc::object_size(length); 177 return (objArrayOop)CollectedHeap::array_allocate(this, size, length, THREAD); 178 } else { 179 report_java_out_of_memory("Requested array size exceeds VM limit"); 180 JvmtiExport::post_array_size_exhausted(); 181 THROW_OOP_0(Universe::out_of_memory_error_array_size()); 182 } 183 } else { 184 THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 185 } 186 } 187 188 static int multi_alloc_counter = 0; 189 190 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 191 int length = *sizes; 192 // Call to lower_dimension uses this pointer, so most be called before a 193 // possible GC 194 Klass* ld_klass = lower_dimension(); 195 // If length < 0 allocate will throw an exception. 196 objArrayOop array = allocate(length, CHECK_NULL); 197 objArrayHandle h_array (THREAD, array); 198 if (rank > 1) { 199 if (length != 0) { 200 for (int index = 0; index < length; index++) { 201 ArrayKlass* ak = ArrayKlass::cast(ld_klass); 202 oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL); 203 h_array->obj_at_put(index, sub_array); 204 } 205 } else { 206 // Since this array dimension has zero length, nothing will be 207 // allocated, however the lower dimension values must be checked 208 // for illegal values. 209 for (int i = 0; i < rank - 1; ++i) { 210 sizes += 1; 211 if (*sizes < 0) { 212 THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 213 } 214 } 215 } 216 } 217 return h_array(); 218 } 219 220 // Either oop or narrowOop depending on UseCompressedOops. 221 template <class T> void ObjArrayKlass::do_copy(arrayOop s, T* src, 222 arrayOop d, T* dst, int length, TRAPS) { 223 224 BarrierSet* bs = Universe::heap()->barrier_set(); 225 // For performance reasons, we assume we are that the write barrier we 226 // are using has optimized modes for arrays of references. At least one 227 // of the asserts below will fail if this is not the case. 228 assert(bs->has_write_ref_array_opt(), "Barrier set must have ref array opt"); 229 assert(bs->has_write_ref_array_pre_opt(), "For pre-barrier as well."); 230 231 if (s == d) { 232 // since source and destination are equal we do not need conversion checks. 233 assert(length > 0, "sanity check"); 234 bs->write_ref_array_pre(dst, length); 235 Copy::conjoint_oops_atomic(src, dst, 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 if (stype == bound || stype->is_subtype_of(bound)) { 241 // elements are guaranteed to be subtypes, so no check necessary 242 bs->write_ref_array_pre(dst, length); 243 Copy::conjoint_oops_atomic(src, dst, length); 244 } else { 245 // slow case: need individual subtype checks 246 // note: don't use obj_at_put below because it includes a redundant store check 247 T* from = src; 248 T* end = from + length; 249 for (T* p = dst; from < end; from++, p++) { 250 // XXX this is going to be slow. 251 T element = *from; 252 // even slower now 253 bool element_is_null = oopDesc::is_null(element); 254 oop new_val = element_is_null ? oop(NULL) 255 : oopDesc::decode_heap_oop_not_null(element); 256 if (element_is_null || 257 (new_val->klass())->is_subtype_of(bound)) { 258 bs->write_ref_field_pre(p, new_val); 259 *p = element; 260 } else { 261 // We must do a barrier to cover the partial copy. 262 const size_t pd = pointer_delta(p, dst, (size_t)heapOopSize); 263 // pointer delta is scaled to number of elements (length field in 264 // objArrayOop) which we assume is 32 bit. 265 assert(pd == (size_t)(int)pd, "length field overflow"); 266 bs->write_ref_array((HeapWord*)dst, pd); 267 THROW(vmSymbols::java_lang_ArrayStoreException()); 268 return; 269 } 270 } 271 } 272 } 273 bs->write_ref_array((HeapWord*)dst, length); 274 } 275 276 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d, 277 int dst_pos, int length, TRAPS) { 278 assert(s->is_objArray(), "must be obj array"); 279 280 if (!d->is_objArray()) { 281 THROW(vmSymbols::java_lang_ArrayStoreException()); 282 } 283 284 // Check is all offsets and lengths are non negative 285 if (src_pos < 0 || dst_pos < 0 || length < 0) { 286 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException()); 287 } 288 // Check if the ranges are valid 289 if ( (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) 290 || (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length()) ) { 291 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException()); 292 } 293 294 // Special case. Boundary cases must be checked first 295 // This allows the following call: copy_array(s, s.length(), d.length(), 0). 296 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(), 297 // points to the right of the last element. 298 if (length==0) { 299 return; 300 } 301 if (UseCompressedOops) { 302 narrowOop* const src = objArrayOop(s)->obj_at_addr<narrowOop>(src_pos); 303 narrowOop* const dst = objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos); 304 do_copy<narrowOop>(s, src, d, dst, length, CHECK); 305 } else { 306 oop* const src = objArrayOop(s)->obj_at_addr<oop>(src_pos); 307 oop* const dst = objArrayOop(d)->obj_at_addr<oop>(dst_pos); 308 do_copy<oop> (s, src, d, dst, length, CHECK); 309 } 310 } 311 312 313 Klass* ObjArrayKlass::array_klass_impl(bool or_null, int n, TRAPS) { 314 315 assert(dimension() <= n, "check order of chain"); 316 int dim = dimension(); 317 if (dim == n) return this; 318 319 // lock-free read needs acquire semantics 320 if (higher_dimension_acquire() == NULL) { 321 if (or_null) return NULL; 322 323 ResourceMark rm; 324 JavaThread *jt = (JavaThread *)THREAD; 325 { 326 MutexLocker mc(Compile_lock, THREAD); // for vtables 327 // Ensure atomic creation of higher dimensions 328 MutexLocker mu(MultiArray_lock, THREAD); 329 330 // Check if another thread beat us 331 if (higher_dimension() == NULL) { 332 333 // Create multi-dim klass object and link them together 334 Klass* k = 335 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL); 336 ObjArrayKlass* ak = ObjArrayKlass::cast(k); 337 ak->set_lower_dimension(this); 338 // use 'release' to pair with lock-free load 339 release_set_higher_dimension(ak); 340 assert(ak->is_objArray_klass(), "incorrect initialization of ObjArrayKlass"); 341 } 342 } 343 } else { 344 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops()); 345 } 346 347 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension()); 348 if (or_null) { 349 return ak->array_klass_or_null(n); 350 } 351 return ak->array_klass(n, THREAD); 352 } 353 354 Klass* ObjArrayKlass::array_klass_impl(bool or_null, TRAPS) { 355 return array_klass_impl(or_null, dimension() + 1, THREAD); 356 } 357 358 bool ObjArrayKlass::can_be_primary_super_slow() const { 359 if (!bottom_klass()->can_be_primary_super()) 360 // array of interfaces 361 return false; 362 else 363 return Klass::can_be_primary_super_slow(); 364 } 365 366 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots) { 367 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... }; 368 Array<Klass*>* elem_supers = element_klass()->secondary_supers(); 369 int num_elem_supers = elem_supers == NULL ? 0 : elem_supers->length(); 370 int num_secondaries = num_extra_slots + 2 + num_elem_supers; 371 if (num_secondaries == 2) { 372 // Must share this for correct bootstrapping! 373 set_secondary_supers(Universe::the_array_interfaces_array()); 374 return NULL; 375 } else { 376 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2); 377 secondaries->push(SystemDictionary::Cloneable_klass()); 378 secondaries->push(SystemDictionary::Serializable_klass()); 379 for (int i = 0; i < num_elem_supers; i++) { 380 Klass* elem_super = (Klass*) elem_supers->at(i); 381 Klass* array_super = elem_super->array_klass_or_null(); 382 assert(array_super != NULL, "must already have been created"); 383 secondaries->push(array_super); 384 } 385 return secondaries; 386 } 387 } 388 389 bool ObjArrayKlass::compute_is_subtype_of(Klass* k) { 390 if (!k->is_objArray_klass()) 391 return ArrayKlass::compute_is_subtype_of(k); 392 393 ObjArrayKlass* oak = ObjArrayKlass::cast(k); 394 return element_klass()->is_subtype_of(oak->element_klass()); 395 } 396 397 void ObjArrayKlass::initialize(TRAPS) { 398 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass 399 } 400 401 // JVM support 402 403 jint ObjArrayKlass::compute_modifier_flags(TRAPS) const { 404 // The modifier for an objectArray is the same as its element 405 if (element_klass() == NULL) { 406 assert(Universe::is_bootstrapping(), "partial objArray only at startup"); 407 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 408 } 409 // Return the flags of the bottom element type. 410 jint element_flags = bottom_klass()->compute_modifier_flags(CHECK_0); 411 412 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED)) 413 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL); 414 } 415 416 ModuleEntry* ObjArrayKlass::module() const { 417 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass"); 418 // The array is defined in the module of its bottom class 419 return bottom_klass()->module(); 420 } 421 422 PackageEntry* ObjArrayKlass::package() const { 423 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass"); 424 return bottom_klass()->package(); 425 } 426 427 // Printing 428 429 void ObjArrayKlass::print_on(outputStream* st) const { 430 #ifndef PRODUCT 431 Klass::print_on(st); 432 st->print(" - instance klass: "); 433 element_klass()->print_value_on(st); 434 st->cr(); 435 #endif //PRODUCT 436 } 437 438 void ObjArrayKlass::print_value_on(outputStream* st) const { 439 assert(is_klass(), "must be klass"); 440 441 element_klass()->print_value_on(st); 442 st->print("[]"); 443 } 444 445 #ifndef PRODUCT 446 447 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) { 448 ArrayKlass::oop_print_on(obj, st); 449 assert(obj->is_objArray(), "must be objArray"); 450 objArrayOop oa = objArrayOop(obj); 451 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize); 452 for(int index = 0; index < print_len; index++) { 453 st->print(" - %3d : ", index); 454 oa->obj_at(index)->print_value_on(st); 455 st->cr(); 456 } 457 int remaining = oa->length() - print_len; 458 if (remaining > 0) { 459 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining); 460 } 461 } 462 463 #endif //PRODUCT 464 465 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) { 466 assert(obj->is_objArray(), "must be objArray"); 467 st->print("a "); 468 element_klass()->print_value_on(st); 469 int len = objArrayOop(obj)->length(); 470 st->print("[%d] ", len); 471 obj->print_address_on(st); 472 } 473 474 const char* ObjArrayKlass::internal_name() const { 475 return external_name(); 476 } 477 478 479 // Verification 480 481 void ObjArrayKlass::verify_on(outputStream* st) { 482 ArrayKlass::verify_on(st); 483 guarantee(element_klass()->is_klass(), "should be klass"); 484 guarantee(bottom_klass()->is_klass(), "should be klass"); 485 Klass* bk = bottom_klass(); 486 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(), "invalid bottom klass"); 487 } 488 489 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) { 490 ArrayKlass::oop_verify_on(obj, st); 491 guarantee(obj->is_objArray(), "must be objArray"); 492 objArrayOop oa = objArrayOop(obj); 493 for(int index = 0; index < oa->length(); index++) { 494 guarantee(oa->obj_at(index)->is_oop_or_null(), "should be oop"); 495 } 496 }