1 /* 2 * Copyright (c) 1997, 2014, 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/symbolTable.hpp" 27 #include "classfile/systemDictionary.hpp" 28 #include "classfile/vmSymbols.hpp" 29 #include "gc_implementation/shared/markSweep.inline.hpp" 30 #include "gc_interface/collectedHeap.inline.hpp" 31 #include "memory/genOopClosures.inline.hpp" 32 #include "memory/iterator.inline.hpp" 33 #include "memory/metadataFactory.hpp" 34 #include "memory/resourceArea.hpp" 35 #include "memory/universe.inline.hpp" 36 #include "oops/instanceKlass.hpp" 37 #include "oops/klass.inline.hpp" 38 #include "oops/objArrayKlass.hpp" 39 #include "oops/objArrayKlass.inline.hpp" 40 #include "oops/objArrayOop.hpp" 41 #include "oops/oop.inline.hpp" 42 #include "oops/oop.inline2.hpp" 43 #include "oops/symbol.hpp" 44 #include "runtime/handles.inline.hpp" 45 #include "runtime/mutexLocker.hpp" 46 #include "runtime/orderAccess.inline.hpp" 47 #include "utilities/copy.hpp" 48 #include "utilities/macros.hpp" 49 #if INCLUDE_ALL_GCS 50 #include "gc_implementation/concurrentMarkSweep/cmsOopClosures.inline.hpp" 51 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" 52 #include "gc_implementation/g1/g1OopClosures.inline.hpp" 53 #include "gc_implementation/g1/g1RemSet.inline.hpp" 54 #include "gc_implementation/g1/heapRegionSeq.inline.hpp" 55 #include "gc_implementation/parNew/parOopClosures.inline.hpp" 56 #include "gc_implementation/parallelScavenge/psCompactionManager.hpp" 57 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp" 58 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp" 59 #include "oops/oop.pcgc.inline.hpp" 60 #endif // INCLUDE_ALL_GCS 61 62 ObjArrayKlass* ObjArrayKlass::allocate(ClassLoaderData* loader_data, int n, KlassHandle klass_handle, Symbol* name, TRAPS) { 63 assert(ObjArrayKlass::header_size() <= InstanceKlass::header_size(), 64 "array klasses must be same size as InstanceKlass"); 65 66 int size = ArrayKlass::static_size(ObjArrayKlass::header_size()); 67 68 return new (loader_data, size, THREAD) ObjArrayKlass(n, klass_handle, name); 69 } 70 71 Klass* ObjArrayKlass::allocate_objArray_klass(ClassLoaderData* loader_data, 72 int n, KlassHandle element_klass, TRAPS) { 73 74 // Eagerly allocate the direct array supertype. 75 KlassHandle super_klass = KlassHandle(); 76 if (!Universe::is_bootstrapping() || SystemDictionary::Object_klass_loaded()) { 77 KlassHandle element_super (THREAD, element_klass->super()); 78 if (element_super.not_null()) { 79 // The element type has a direct super. E.g., String[] has direct super of Object[]. 80 super_klass = KlassHandle(THREAD, element_super->array_klass_or_null()); 81 bool supers_exist = super_klass.not_null(); 82 // Also, see if the element has secondary supertypes. 83 // We need an array type for each. 84 Array<Klass*>* element_supers = element_klass->secondary_supers(); 85 for( int i = element_supers->length()-1; i >= 0; i-- ) { 86 Klass* elem_super = element_supers->at(i); 87 if (elem_super->array_klass_or_null() == NULL) { 88 supers_exist = false; 89 break; 90 } 91 } 92 if (!supers_exist) { 93 // Oops. Not allocated yet. Back out, allocate it, and retry. 94 KlassHandle ek; 95 { 96 MutexUnlocker mu(MultiArray_lock); 97 MutexUnlocker mc(Compile_lock); // for vtables 98 Klass* sk = element_super->array_klass(CHECK_0); 99 super_klass = KlassHandle(THREAD, sk); 100 for( int i = element_supers->length()-1; i >= 0; i-- ) { 101 KlassHandle elem_super (THREAD, element_supers->at(i)); 102 elem_super->array_klass(CHECK_0); 103 } 104 // Now retry from the beginning 105 Klass* klass_oop = element_klass->array_klass(n, CHECK_0); 106 // Create a handle because the enclosing brace, when locking 107 // can cause a gc. Better to have this function return a Handle. 108 ek = KlassHandle(THREAD, klass_oop); 109 } // re-lock 110 return ek(); 111 } 112 } else { 113 // The element type is already Object. Object[] has direct super of Object. 114 super_klass = KlassHandle(THREAD, SystemDictionary::Object_klass()); 115 } 116 } 117 118 // Create type name for klass. 119 Symbol* name = NULL; 120 if (!element_klass->oop_is_instance() || 121 (name = InstanceKlass::cast(element_klass())->array_name()) == NULL) { 122 123 ResourceMark rm(THREAD); 124 char *name_str = element_klass->name()->as_C_string(); 125 int len = element_klass->name()->utf8_length(); 126 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4); 127 int idx = 0; 128 new_str[idx++] = '['; 129 if (element_klass->oop_is_instance()) { // it could be an array or simple type 130 new_str[idx++] = 'L'; 131 } 132 memcpy(&new_str[idx], name_str, len * sizeof(char)); 133 idx += len; 134 if (element_klass->oop_is_instance()) { 135 new_str[idx++] = ';'; 136 } 137 new_str[idx++] = '\0'; 138 name = SymbolTable::new_permanent_symbol(new_str, CHECK_0); 139 if (element_klass->oop_is_instance()) { 140 InstanceKlass* ik = InstanceKlass::cast(element_klass()); 141 ik->set_array_name(name); 142 } 143 } 144 145 // Initialize instance variables 146 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_0); 147 148 // Add all classes to our internal class loader list here, 149 // including classes in the bootstrap (NULL) class loader. 150 // GC walks these as strong roots. 151 loader_data->add_class(oak); 152 153 // Call complete_create_array_klass after all instance variables has been initialized. 154 ArrayKlass::complete_create_array_klass(oak, super_klass, CHECK_0); 155 156 return oak; 157 } 158 159 ObjArrayKlass::ObjArrayKlass(int n, KlassHandle element_klass, Symbol* name) : ArrayKlass(name, _obj_array) { 160 this->set_dimension(n); 161 this->set_element_klass(element_klass()); 162 // decrement refcount because object arrays are not explicitly freed. The 163 // InstanceKlass array_name() keeps the name counted while the klass is 164 // loaded. 165 name->decrement_refcount(); 166 167 Klass* bk; 168 if (element_klass->oop_is_objArray()) { 169 bk = ObjArrayKlass::cast(element_klass())->bottom_klass(); 170 } else { 171 bk = element_klass(); 172 } 173 assert(bk != NULL && (bk->oop_is_instance() || bk->oop_is_typeArray()), "invalid bottom klass"); 174 this->set_bottom_klass(bk); 175 this->set_class_loader_data(bk->class_loader_data()); 176 177 this->set_layout_helper(array_layout_helper(T_OBJECT)); 178 assert(this->oop_is_array(), "sanity"); 179 assert(this->oop_is_objArray(), "sanity"); 180 } 181 182 int ObjArrayKlass::oop_size(oop obj) const { 183 assert(obj->is_objArray(), "must be object array"); 184 return objArrayOop(obj)->object_size(); 185 } 186 187 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) { 188 if (length >= 0) { 189 if (length <= arrayOopDesc::max_array_length(T_OBJECT)) { 190 int size = objArrayOopDesc::object_size(length); 191 KlassHandle h_k(THREAD, this); 192 return (objArrayOop)CollectedHeap::array_allocate(h_k, size, length, CHECK_NULL); 193 } else { 194 report_java_out_of_memory("Requested array size exceeds VM limit"); 195 JvmtiExport::post_array_size_exhausted(); 196 THROW_OOP_0(Universe::out_of_memory_error_array_size()); 197 } 198 } else { 199 THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 200 } 201 } 202 203 static int multi_alloc_counter = 0; 204 205 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 206 int length = *sizes; 207 // Call to lower_dimension uses this pointer, so most be called before a 208 // possible GC 209 KlassHandle h_lower_dimension(THREAD, lower_dimension()); 210 // If length < 0 allocate will throw an exception. 211 objArrayOop array = allocate(length, CHECK_NULL); 212 objArrayHandle h_array (THREAD, array); 213 if (rank > 1) { 214 if (length != 0) { 215 for (int index = 0; index < length; index++) { 216 ArrayKlass* ak = ArrayKlass::cast(h_lower_dimension()); 217 oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL); 218 h_array->obj_at_put(index, sub_array); 219 } 220 } else { 221 // Since this array dimension has zero length, nothing will be 222 // allocated, however the lower dimension values must be checked 223 // for illegal values. 224 for (int i = 0; i < rank - 1; ++i) { 225 sizes += 1; 226 if (*sizes < 0) { 227 THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 228 } 229 } 230 } 231 } 232 return h_array(); 233 } 234 235 // Either oop or narrowOop depending on UseCompressedOops. 236 template <class T> void ObjArrayKlass::do_copy(arrayOop s, T* src, 237 arrayOop d, T* dst, int length, TRAPS) { 238 239 BarrierSet* bs = Universe::heap()->barrier_set(); 240 // For performance reasons, we assume we are that the write barrier we 241 // are using has optimized modes for arrays of references. At least one 242 // of the asserts below will fail if this is not the case. 243 assert(bs->has_write_ref_array_opt(), "Barrier set must have ref array opt"); 244 assert(bs->has_write_ref_array_pre_opt(), "For pre-barrier as well."); 245 246 if (s == d) { 247 // since source and destination are equal we do not need conversion checks. 248 assert(length > 0, "sanity check"); 249 bs->write_ref_array_pre(dst, length); 250 Copy::conjoint_oops_atomic(src, dst, length); 251 } else { 252 // We have to make sure all elements conform to the destination array 253 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass(); 254 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass(); 255 if (stype == bound || stype->is_subtype_of(bound)) { 256 // elements are guaranteed to be subtypes, so no check necessary 257 bs->write_ref_array_pre(dst, length); 258 Copy::conjoint_oops_atomic(src, dst, length); 259 } else { 260 // slow case: need individual subtype checks 261 // note: don't use obj_at_put below because it includes a redundant store check 262 T* from = src; 263 T* end = from + length; 264 for (T* p = dst; from < end; from++, p++) { 265 // XXX this is going to be slow. 266 T element = *from; 267 // even slower now 268 bool element_is_null = oopDesc::is_null(element); 269 oop new_val = element_is_null ? oop(NULL) 270 : oopDesc::decode_heap_oop_not_null(element); 271 if (element_is_null || 272 (new_val->klass())->is_subtype_of(bound)) { 273 bs->write_ref_field_pre(p, new_val); 274 *p = element; 275 } else { 276 // We must do a barrier to cover the partial copy. 277 const size_t pd = pointer_delta(p, dst, (size_t)heapOopSize); 278 // pointer delta is scaled to number of elements (length field in 279 // objArrayOop) which we assume is 32 bit. 280 assert(pd == (size_t)(int)pd, "length field overflow"); 281 bs->write_ref_array((HeapWord*)dst, pd); 282 THROW(vmSymbols::java_lang_ArrayStoreException()); 283 return; 284 } 285 } 286 } 287 } 288 bs->write_ref_array((HeapWord*)dst, length); 289 } 290 291 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d, 292 int dst_pos, int length, TRAPS) { 293 assert(s->is_objArray(), "must be obj array"); 294 295 if (!d->is_objArray()) { 296 THROW(vmSymbols::java_lang_ArrayStoreException()); 297 } 298 299 // Check is all offsets and lengths are non negative 300 if (src_pos < 0 || dst_pos < 0 || length < 0) { 301 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException()); 302 } 303 // Check if the ranges are valid 304 if ( (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) 305 || (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length()) ) { 306 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException()); 307 } 308 309 // Special case. Boundary cases must be checked first 310 // This allows the following call: copy_array(s, s.length(), d.length(), 0). 311 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(), 312 // points to the right of the last element. 313 if (length==0) { 314 return; 315 } 316 if (UseCompressedOops) { 317 narrowOop* const src = objArrayOop(s)->obj_at_addr<narrowOop>(src_pos); 318 narrowOop* const dst = objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos); 319 do_copy<narrowOop>(s, src, d, dst, length, CHECK); 320 } else { 321 oop* const src = objArrayOop(s)->obj_at_addr<oop>(src_pos); 322 oop* const dst = objArrayOop(d)->obj_at_addr<oop>(dst_pos); 323 do_copy<oop> (s, src, d, dst, length, CHECK); 324 } 325 } 326 327 328 Klass* ObjArrayKlass::array_klass_impl(bool or_null, int n, TRAPS) { 329 330 assert(dimension() <= n, "check order of chain"); 331 int dim = dimension(); 332 if (dim == n) return this; 333 334 if (higher_dimension() == NULL) { 335 if (or_null) return NULL; 336 337 ResourceMark rm; 338 JavaThread *jt = (JavaThread *)THREAD; 339 { 340 MutexLocker mc(Compile_lock, THREAD); // for vtables 341 // Ensure atomic creation of higher dimensions 342 MutexLocker mu(MultiArray_lock, THREAD); 343 344 // Check if another thread beat us 345 if (higher_dimension() == NULL) { 346 347 // Create multi-dim klass object and link them together 348 Klass* k = 349 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL); 350 ObjArrayKlass* ak = ObjArrayKlass::cast(k); 351 ak->set_lower_dimension(this); 352 OrderAccess::storestore(); 353 set_higher_dimension(ak); 354 assert(ak->oop_is_objArray(), "incorrect initialization of ObjArrayKlass"); 355 } 356 } 357 } else { 358 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops()); 359 } 360 361 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension()); 362 if (or_null) { 363 return ak->array_klass_or_null(n); 364 } 365 return ak->array_klass(n, CHECK_NULL); 366 } 367 368 Klass* ObjArrayKlass::array_klass_impl(bool or_null, TRAPS) { 369 return array_klass_impl(or_null, dimension() + 1, CHECK_NULL); 370 } 371 372 bool ObjArrayKlass::can_be_primary_super_slow() const { 373 if (!bottom_klass()->can_be_primary_super()) 374 // array of interfaces 375 return false; 376 else 377 return Klass::can_be_primary_super_slow(); 378 } 379 380 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots) { 381 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... }; 382 Array<Klass*>* elem_supers = element_klass()->secondary_supers(); 383 int num_elem_supers = elem_supers == NULL ? 0 : elem_supers->length(); 384 int num_secondaries = num_extra_slots + 2 + num_elem_supers; 385 if (num_secondaries == 2) { 386 // Must share this for correct bootstrapping! 387 set_secondary_supers(Universe::the_array_interfaces_array()); 388 return NULL; 389 } else { 390 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2); 391 secondaries->push(SystemDictionary::Cloneable_klass()); 392 secondaries->push(SystemDictionary::Serializable_klass()); 393 for (int i = 0; i < num_elem_supers; i++) { 394 Klass* elem_super = (Klass*) elem_supers->at(i); 395 Klass* array_super = elem_super->array_klass_or_null(); 396 assert(array_super != NULL, "must already have been created"); 397 secondaries->push(array_super); 398 } 399 return secondaries; 400 } 401 } 402 403 bool ObjArrayKlass::compute_is_subtype_of(Klass* k) { 404 if (!k->oop_is_objArray()) 405 return ArrayKlass::compute_is_subtype_of(k); 406 407 ObjArrayKlass* oak = ObjArrayKlass::cast(k); 408 return element_klass()->is_subtype_of(oak->element_klass()); 409 } 410 411 void ObjArrayKlass::initialize(TRAPS) { 412 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass 413 } 414 415 void ObjArrayKlass::oop_follow_contents(oop obj) { 416 assert (obj->is_array(), "obj must be array"); 417 MarkSweep::follow_klass(obj->klass()); 418 if (UseCompressedOops) { 419 objarray_follow_contents<narrowOop>(obj, 0); 420 } else { 421 objarray_follow_contents<oop>(obj, 0); 422 } 423 } 424 425 #if INCLUDE_ALL_GCS 426 void ObjArrayKlass::oop_follow_contents(ParCompactionManager* cm, 427 oop obj) { 428 assert(obj->is_array(), "obj must be array"); 429 PSParallelCompact::follow_klass(cm, obj->klass()); 430 if (UseCompressedOops) { 431 objarray_follow_contents<narrowOop>(cm, obj, 0); 432 } else { 433 objarray_follow_contents<oop>(cm, obj, 0); 434 } 435 } 436 #endif // INCLUDE_ALL_GCS 437 438 int ObjArrayKlass::oop_adjust_pointers(oop obj) { 439 assert(obj->is_objArray(), "obj must be obj array"); 440 objArrayOop a = objArrayOop(obj); 441 // Get size before changing pointers. 442 // Don't call size() or oop_size() since that is a virtual call. 443 int size = a->object_size(); 444 ObjArrayKlass_OOP_ITERATE(a, p, MarkSweep::adjust_pointer(p)) 445 return size; 446 } 447 448 #if INCLUDE_ALL_GCS 449 void ObjArrayKlass::oop_push_contents(PSPromotionManager* pm, oop obj) { 450 assert(obj->is_objArray(), "obj must be obj array"); 451 ObjArrayKlass_OOP_ITERATE( \ 452 objArrayOop(obj), p, \ 453 if (PSScavenge::should_scavenge(p)) { \ 454 pm->claim_or_forward_depth(p); \ 455 }) 456 } 457 458 int ObjArrayKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) { 459 assert (obj->is_objArray(), "obj must be obj array"); 460 objArrayOop a = objArrayOop(obj); 461 int size = a->object_size(); 462 ObjArrayKlass_OOP_ITERATE(a, p, PSParallelCompact::adjust_pointer(p)) 463 return size; 464 } 465 #endif // INCLUDE_ALL_GCS 466 467 // JVM support 468 469 jint ObjArrayKlass::compute_modifier_flags(TRAPS) const { 470 // The modifier for an objectArray is the same as its element 471 if (element_klass() == NULL) { 472 assert(Universe::is_bootstrapping(), "partial objArray only at startup"); 473 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 474 } 475 // Return the flags of the bottom element type. 476 jint element_flags = bottom_klass()->compute_modifier_flags(CHECK_0); 477 478 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED)) 479 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL); 480 } 481 482 483 // Printing 484 485 void ObjArrayKlass::print_on(outputStream* st) const { 486 #ifndef PRODUCT 487 Klass::print_on(st); 488 st->print(" - instance klass: "); 489 element_klass()->print_value_on(st); 490 st->cr(); 491 #endif //PRODUCT 492 } 493 494 void ObjArrayKlass::print_value_on(outputStream* st) const { 495 assert(is_klass(), "must be klass"); 496 497 element_klass()->print_value_on(st); 498 st->print("[]"); 499 } 500 501 #ifndef PRODUCT 502 503 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) { 504 ArrayKlass::oop_print_on(obj, st); 505 assert(obj->is_objArray(), "must be objArray"); 506 objArrayOop oa = objArrayOop(obj); 507 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize); 508 for(int index = 0; index < print_len; index++) { 509 st->print(" - %3d : ", index); 510 oa->obj_at(index)->print_value_on(st); 511 st->cr(); 512 } 513 int remaining = oa->length() - print_len; 514 if (remaining > 0) { 515 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining); 516 } 517 } 518 519 #endif //PRODUCT 520 521 static int max_objArray_print_length = 4; 522 523 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) { 524 assert(obj->is_objArray(), "must be objArray"); 525 st->print("a "); 526 element_klass()->print_value_on(st); 527 int len = objArrayOop(obj)->length(); 528 st->print("[%d] ", len); 529 obj->print_address_on(st); 530 if (NOT_PRODUCT(PrintOopAddress ||) PrintMiscellaneous && (WizardMode || Verbose)) { 531 st->print("{"); 532 for (int i = 0; i < len; i++) { 533 if (i > max_objArray_print_length) { 534 st->print("..."); break; 535 } 536 st->print(" "INTPTR_FORMAT, (intptr_t)(void*)objArrayOop(obj)->obj_at(i)); 537 } 538 st->print(" }"); 539 } 540 } 541 542 const char* ObjArrayKlass::internal_name() const { 543 return external_name(); 544 } 545 546 547 // Verification 548 549 void ObjArrayKlass::verify_on(outputStream* st) { 550 ArrayKlass::verify_on(st); 551 guarantee(element_klass()->is_klass(), "should be klass"); 552 guarantee(bottom_klass()->is_klass(), "should be klass"); 553 Klass* bk = bottom_klass(); 554 guarantee(bk->oop_is_instance() || bk->oop_is_typeArray(), "invalid bottom klass"); 555 } 556 557 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) { 558 ArrayKlass::oop_verify_on(obj, st); 559 guarantee(obj->is_objArray(), "must be objArray"); 560 objArrayOop oa = objArrayOop(obj); 561 for(int index = 0; index < oa->length(); index++) { 562 guarantee(oa->obj_at(index)->is_oop_or_null(), "should be oop"); 563 } 564 }