1 /* 2 * Copyright (c) 1997, 2015, 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/shared/collectedHeap.inline.hpp" 30 #include "gc/shared/specialized_oop_closures.hpp" 31 #include "memory/iterator.inline.hpp" 32 #include "memory/metadataFactory.hpp" 33 #include "memory/resourceArea.hpp" 34 #include "memory/universe.inline.hpp" 35 #include "oops/instanceKlass.hpp" 36 #include "oops/klass.inline.hpp" 37 #include "oops/objArrayKlass.inline.hpp" 38 #include "oops/objArrayOop.inline.hpp" 39 #include "oops/oop.inline.hpp" 40 #include "oops/symbol.hpp" 41 #include "runtime/handles.inline.hpp" 42 #include "runtime/mutexLocker.hpp" 43 #include "runtime/orderAccess.inline.hpp" 44 #include "utilities/copy.hpp" 45 #include "utilities/macros.hpp" 46 47 ObjArrayKlass* ObjArrayKlass::allocate(ClassLoaderData* loader_data, int n, KlassHandle klass_handle, 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, klass_handle, name); 54 } 55 56 Klass* ObjArrayKlass::allocate_objArray_klass(ClassLoaderData* loader_data, 57 int n, KlassHandle element_klass, TRAPS) { 58 59 // Eagerly allocate the direct array supertype. 60 KlassHandle super_klass = KlassHandle(); 61 if (!Universe::is_bootstrapping() || SystemDictionary::Object_klass_loaded()) { 62 KlassHandle element_super (THREAD, element_klass->super()); 63 if (element_super.not_null()) { 64 // The element type has a direct super. E.g., String[] has direct super of Object[]. 65 super_klass = KlassHandle(THREAD, element_super->array_klass_or_null()); 66 bool supers_exist = super_klass.not_null(); 67 // Also, see if the element has secondary supertypes. 68 // We need an array type for each. 69 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 if (elem_super->array_klass_or_null() == NULL) { 73 supers_exist = false; 74 break; 75 } 76 } 77 if (!supers_exist) { 78 // Oops. Not allocated yet. Back out, allocate it, and retry. 79 KlassHandle ek; 80 { 81 MutexUnlocker mu(MultiArray_lock); 82 MutexUnlocker mc(Compile_lock); // for vtables 83 Klass* sk = element_super->array_klass(CHECK_0); 84 super_klass = KlassHandle(THREAD, sk); 85 for( int i = element_supers->length()-1; i >= 0; i-- ) { 86 KlassHandle elem_super (THREAD, element_supers->at(i)); 87 elem_super->array_klass(CHECK_0); 88 } 89 // Now retry from the beginning 90 Klass* klass_oop = element_klass->array_klass(n, CHECK_0); 91 // Create a handle because the enclosing brace, when locking 92 // can cause a gc. Better to have this function return a Handle. 93 ek = KlassHandle(THREAD, klass_oop); 94 } // re-lock 95 return ek(); 96 } 97 } else { 98 // The element type is already Object. Object[] has direct super of Object. 99 super_klass = KlassHandle(THREAD, SystemDictionary::Object_klass()); 100 } 101 } 102 103 // Create type name for klass. 104 Symbol* name = NULL; 105 if (!element_klass->oop_is_instance() || 106 (name = InstanceKlass::cast(element_klass())->array_name()) == NULL) { 107 108 ResourceMark rm(THREAD); 109 char *name_str = element_klass->name()->as_C_string(); 110 int len = element_klass->name()->utf8_length(); 111 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4); 112 int idx = 0; 113 new_str[idx++] = '['; 114 if (element_klass->oop_is_instance()) { // it could be an array or simple type 115 new_str[idx++] = 'L'; 116 } 117 memcpy(&new_str[idx], name_str, len * sizeof(char)); 118 idx += len; 119 if (element_klass->oop_is_instance()) { 120 new_str[idx++] = ';'; 121 } 122 new_str[idx++] = '\0'; 123 name = SymbolTable::new_permanent_symbol(new_str, CHECK_0); 124 if (element_klass->oop_is_instance()) { 125 InstanceKlass* ik = InstanceKlass::cast(element_klass()); 126 ik->set_array_name(name); 127 } 128 } 129 130 // Initialize instance variables 131 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_0); 132 133 // Add all classes to our internal class loader list here, 134 // including classes in the bootstrap (NULL) class loader. 135 // GC walks these as strong roots. 136 loader_data->add_class(oak); 137 138 // Call complete_create_array_klass after all instance variables has been initialized. 139 ArrayKlass::complete_create_array_klass(oak, super_klass, CHECK_0); 140 141 return oak; 142 } 143 144 ObjArrayKlass::ObjArrayKlass(int n, KlassHandle element_klass, Symbol* name) : ArrayKlass(name) { 145 this->set_dimension(n); 146 this->set_element_klass(element_klass()); 147 // decrement refcount because object arrays are not explicitly freed. The 148 // InstanceKlass array_name() keeps the name counted while the klass is 149 // loaded. 150 name->decrement_refcount(); 151 152 Klass* bk; 153 if (element_klass->oop_is_objArray()) { 154 bk = ObjArrayKlass::cast(element_klass())->bottom_klass(); 155 } else { 156 bk = element_klass(); 157 } 158 assert(bk != NULL && (bk->oop_is_instance() || bk->oop_is_typeArray()), "invalid bottom klass"); 159 this->set_bottom_klass(bk); 160 this->set_class_loader_data(bk->class_loader_data()); 161 162 this->set_layout_helper(array_layout_helper(T_OBJECT)); 163 assert(this->oop_is_array(), "sanity"); 164 assert(this->oop_is_objArray(), "sanity"); 165 } 166 167 int ObjArrayKlass::oop_size(oop obj) const { 168 assert(obj->is_objArray(), "must be object array"); 169 return objArrayOop(obj)->object_size(); 170 } 171 172 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) { 173 if (length >= 0) { 174 if (length <= arrayOopDesc::max_array_length(T_OBJECT)) { 175 int size = objArrayOopDesc::object_size(length); 176 KlassHandle h_k(THREAD, this); 177 return (objArrayOop)CollectedHeap::array_allocate(h_k, 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 KlassHandle h_lower_dimension(THREAD, 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(h_lower_dimension()); 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 if (higher_dimension() == NULL) { 320 if (or_null) return NULL; 321 322 ResourceMark rm; 323 JavaThread *jt = (JavaThread *)THREAD; 324 { 325 MutexLocker mc(Compile_lock, THREAD); // for vtables 326 // Ensure atomic creation of higher dimensions 327 MutexLocker mu(MultiArray_lock, THREAD); 328 329 // Check if another thread beat us 330 if (higher_dimension() == NULL) { 331 332 // Create multi-dim klass object and link them together 333 Klass* k = 334 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL); 335 ObjArrayKlass* ak = ObjArrayKlass::cast(k); 336 ak->set_lower_dimension(this); 337 OrderAccess::storestore(); 338 set_higher_dimension(ak); 339 assert(ak->oop_is_objArray(), "incorrect initialization of ObjArrayKlass"); 340 } 341 } 342 } else { 343 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops()); 344 } 345 346 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension()); 347 if (or_null) { 348 return ak->array_klass_or_null(n); 349 } 350 return ak->array_klass(n, THREAD); 351 } 352 353 Klass* ObjArrayKlass::array_klass_impl(bool or_null, TRAPS) { 354 return array_klass_impl(or_null, dimension() + 1, THREAD); 355 } 356 357 bool ObjArrayKlass::can_be_primary_super_slow() const { 358 if (!bottom_klass()->can_be_primary_super()) 359 // array of interfaces 360 return false; 361 else 362 return Klass::can_be_primary_super_slow(); 363 } 364 365 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots) { 366 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... }; 367 Array<Klass*>* elem_supers = element_klass()->secondary_supers(); 368 int num_elem_supers = elem_supers == NULL ? 0 : elem_supers->length(); 369 int num_secondaries = num_extra_slots + 2 + num_elem_supers; 370 if (num_secondaries == 2) { 371 // Must share this for correct bootstrapping! 372 set_secondary_supers(Universe::the_array_interfaces_array()); 373 return NULL; 374 } else { 375 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2); 376 secondaries->push(SystemDictionary::Cloneable_klass()); 377 secondaries->push(SystemDictionary::Serializable_klass()); 378 for (int i = 0; i < num_elem_supers; i++) { 379 Klass* elem_super = (Klass*) elem_supers->at(i); 380 Klass* array_super = elem_super->array_klass_or_null(); 381 assert(array_super != NULL, "must already have been created"); 382 secondaries->push(array_super); 383 } 384 return secondaries; 385 } 386 } 387 388 bool ObjArrayKlass::compute_is_subtype_of(Klass* k) { 389 if (!k->oop_is_objArray()) 390 return ArrayKlass::compute_is_subtype_of(k); 391 392 ObjArrayKlass* oak = ObjArrayKlass::cast(k); 393 return element_klass()->is_subtype_of(oak->element_klass()); 394 } 395 396 void ObjArrayKlass::initialize(TRAPS) { 397 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass 398 } 399 400 // JVM support 401 402 jint ObjArrayKlass::compute_modifier_flags(TRAPS) const { 403 // The modifier for an objectArray is the same as its element 404 if (element_klass() == NULL) { 405 assert(Universe::is_bootstrapping(), "partial objArray only at startup"); 406 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 407 } 408 // Return the flags of the bottom element type. 409 jint element_flags = bottom_klass()->compute_modifier_flags(CHECK_0); 410 411 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED)) 412 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL); 413 } 414 415 416 // Printing 417 418 void ObjArrayKlass::print_on(outputStream* st) const { 419 #ifndef PRODUCT 420 Klass::print_on(st); 421 st->print(" - instance klass: "); 422 element_klass()->print_value_on(st); 423 st->cr(); 424 #endif //PRODUCT 425 } 426 427 void ObjArrayKlass::print_value_on(outputStream* st) const { 428 assert(is_klass(), "must be klass"); 429 430 element_klass()->print_value_on(st); 431 st->print("[]"); 432 } 433 434 #ifndef PRODUCT 435 436 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) { 437 ArrayKlass::oop_print_on(obj, st); 438 assert(obj->is_objArray(), "must be objArray"); 439 objArrayOop oa = objArrayOop(obj); 440 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize); 441 for(int index = 0; index < print_len; index++) { 442 st->print(" - %3d : ", index); 443 oa->obj_at(index)->print_value_on(st); 444 st->cr(); 445 } 446 int remaining = oa->length() - print_len; 447 if (remaining > 0) { 448 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining); 449 } 450 } 451 452 #endif //PRODUCT 453 454 static int max_objArray_print_length = 4; 455 456 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) { 457 assert(obj->is_objArray(), "must be objArray"); 458 st->print("a "); 459 element_klass()->print_value_on(st); 460 int len = objArrayOop(obj)->length(); 461 st->print("[%d] ", len); 462 obj->print_address_on(st); 463 if (NOT_PRODUCT(PrintOopAddress ||) PrintMiscellaneous && (WizardMode || Verbose)) { 464 st->print("{"); 465 for (int i = 0; i < len; i++) { 466 if (i > max_objArray_print_length) { 467 st->print("..."); break; 468 } 469 st->print(" "INTPTR_FORMAT, (intptr_t)(void*)objArrayOop(obj)->obj_at(i)); 470 } 471 st->print(" }"); 472 } 473 } 474 475 const char* ObjArrayKlass::internal_name() const { 476 return external_name(); 477 } 478 479 480 // Verification 481 482 void ObjArrayKlass::verify_on(outputStream* st) { 483 ArrayKlass::verify_on(st); 484 guarantee(element_klass()->is_klass(), "should be klass"); 485 guarantee(bottom_klass()->is_klass(), "should be klass"); 486 Klass* bk = bottom_klass(); 487 guarantee(bk->oop_is_instance() || bk->oop_is_typeArray(), "invalid bottom klass"); 488 } 489 490 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) { 491 ArrayKlass::oop_verify_on(obj, st); 492 guarantee(obj->is_objArray(), "must be objArray"); 493 objArrayOop oa = objArrayOop(obj); 494 for(int index = 0; index < oa->length(); index++) { 495 guarantee(oa->obj_at(index)->is_oop_or_null(), "should be oop"); 496 } 497 }