1 /* 2 * Copyright (c) 1997, 2016, 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/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 "runtime/orderAccess.inline.hpp" 46 #include "utilities/copy.hpp" 47 #include "utilities/macros.hpp" 48 49 ObjArrayKlass* ObjArrayKlass::allocate(ClassLoaderData* loader_data, int n, KlassHandle klass_handle, 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, klass_handle, name); 56 } 57 58 Klass* ObjArrayKlass::allocate_objArray_klass(ClassLoaderData* loader_data, 59 int n, KlassHandle element_klass, TRAPS) { 60 61 // Eagerly allocate the direct array supertype. 62 KlassHandle super_klass = KlassHandle(); 63 if (!Universe::is_bootstrapping() || SystemDictionary::Object_klass_loaded()) { 64 KlassHandle element_super (THREAD, element_klass->super()); 65 if (element_super.not_null()) { 66 // The element type has a direct super. E.g., String[] has direct super of Object[]. 67 super_klass = KlassHandle(THREAD, element_super->array_klass_or_null()); 68 bool supers_exist = super_klass.not_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 KlassHandle ek; 82 { 83 MutexUnlocker mu(MultiArray_lock); 84 MutexUnlocker mc(Compile_lock); // for vtables 85 Klass* sk = element_super->array_klass(CHECK_0); 86 super_klass = KlassHandle(THREAD, sk); 87 for( int i = element_supers->length()-1; i >= 0; i-- ) { 88 KlassHandle elem_super (THREAD, element_supers->at(i)); 89 elem_super->array_klass(CHECK_0); 90 } 91 // Now retry from the beginning 92 Klass* klass_oop = element_klass->array_klass(n, CHECK_0); 93 // Create a handle because the enclosing brace, when locking 94 // can cause a gc. Better to have this function return a Handle. 95 ek = KlassHandle(THREAD, klass_oop); 96 } // re-lock 97 return ek(); 98 } 99 } else { 100 // The element type is already Object. Object[] has direct super of Object. 101 super_klass = KlassHandle(THREAD, SystemDictionary::Object_klass()); 102 } 103 } 104 105 // Create type name for klass. 106 Symbol* name = NULL; 107 if (!element_klass->is_instance_klass() || 108 (name = InstanceKlass::cast(element_klass())->array_name()) == NULL) { 109 110 ResourceMark rm(THREAD); 111 char *name_str = element_klass->name()->as_C_string(); 112 int len = element_klass->name()->utf8_length(); 113 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4); 114 int idx = 0; 115 new_str[idx++] = '['; 116 if (element_klass->is_instance_klass()) { // it could be an array or simple type 117 new_str[idx++] = 'L'; 118 } 119 memcpy(&new_str[idx], name_str, len * sizeof(char)); 120 idx += len; 121 if (element_klass->is_instance_klass()) { 122 new_str[idx++] = ';'; 123 } 124 new_str[idx++] = '\0'; 125 name = SymbolTable::new_permanent_symbol(new_str, CHECK_0); 126 if (element_klass->is_instance_klass()) { 127 InstanceKlass* ik = InstanceKlass::cast(element_klass()); 128 ik->set_array_name(name); 129 } 130 } 131 132 // Initialize instance variables 133 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_0); 134 135 // Add all classes to our internal class loader list here, 136 // including classes in the bootstrap (NULL) class loader. 137 // GC walks these as strong roots. 138 loader_data->add_class(oak); 139 140 ModuleEntry* module = oak->module(); 141 assert(module != NULL, "No module entry for array"); 142 143 // Call complete_create_array_klass after all instance variables has been initialized. 144 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_0); 145 146 return oak; 147 } 148 149 ObjArrayKlass::ObjArrayKlass(int n, KlassHandle element_klass, Symbol* name) : ArrayKlass(name) { 150 this->set_dimension(n); 151 this->set_element_klass(element_klass()); 152 // decrement refcount because object arrays are not explicitly freed. The 153 // InstanceKlass array_name() keeps the name counted while the klass is 154 // loaded. 155 name->decrement_refcount(); 156 157 Klass* bk; 158 if (element_klass->is_objArray_klass()) { 159 bk = ObjArrayKlass::cast(element_klass())->bottom_klass(); 160 } else { 161 bk = element_klass(); 162 } 163 assert(bk != NULL && (bk->is_instance_klass() || bk->is_typeArray_klass()), "invalid bottom klass"); 164 this->set_bottom_klass(bk); 165 this->set_class_loader_data(bk->class_loader_data()); 166 167 this->set_layout_helper(array_layout_helper(T_OBJECT)); 168 assert(this->is_array_klass(), "sanity"); 169 assert(this->is_objArray_klass(), "sanity"); 170 } 171 172 int ObjArrayKlass::oop_size(oop obj) const { 173 assert(obj->is_objArray(), "must be object array"); 174 return objArrayOop(obj)->object_size(); 175 } 176 177 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) { 178 if (length >= 0) { 179 if (length <= arrayOopDesc::max_array_length(T_OBJECT)) { 180 int size = objArrayOopDesc::object_size(length); 181 KlassHandle h_k(THREAD, this); 182 return (objArrayOop)CollectedHeap::array_allocate(h_k, size, length, THREAD); 183 } else { 184 report_java_out_of_memory("Requested array size exceeds VM limit"); 185 JvmtiExport::post_array_size_exhausted(); 186 THROW_OOP_0(Universe::out_of_memory_error_array_size()); 187 } 188 } else { 189 THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 190 } 191 } 192 193 static int multi_alloc_counter = 0; 194 195 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 196 int length = *sizes; 197 // Call to lower_dimension uses this pointer, so most be called before a 198 // possible GC 199 KlassHandle h_lower_dimension(THREAD, lower_dimension()); 200 // If length < 0 allocate will throw an exception. 201 objArrayOop array = allocate(length, CHECK_NULL); 202 objArrayHandle h_array (THREAD, array); 203 if (rank > 1) { 204 if (length != 0) { 205 for (int index = 0; index < length; index++) { 206 ArrayKlass* ak = ArrayKlass::cast(h_lower_dimension()); 207 oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL); 208 h_array->obj_at_put(index, sub_array); 209 } 210 } else { 211 // Since this array dimension has zero length, nothing will be 212 // allocated, however the lower dimension values must be checked 213 // for illegal values. 214 for (int i = 0; i < rank - 1; ++i) { 215 sizes += 1; 216 if (*sizes < 0) { 217 THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 218 } 219 } 220 } 221 } 222 return h_array(); 223 } 224 225 // Either oop or narrowOop depending on UseCompressedOops. 226 template <class T> void ObjArrayKlass::do_copy(arrayOop s, T* src, 227 arrayOop d, T* dst, int length, TRAPS) { 228 229 BarrierSet* bs = Universe::heap()->barrier_set(); 230 // For performance reasons, we assume we are that the write barrier we 231 // are using has optimized modes for arrays of references. At least one 232 // of the asserts below will fail if this is not the case. 233 assert(bs->has_write_ref_array_opt(), "Barrier set must have ref array opt"); 234 assert(bs->has_write_ref_array_pre_opt(), "For pre-barrier as well."); 235 236 if (s == d) { 237 // since source and destination are equal we do not need conversion checks. 238 assert(length > 0, "sanity check"); 239 bs->write_ref_array_pre(dst, length); 240 Copy::conjoint_oops_atomic(src, dst, length); 241 } else { 242 // We have to make sure all elements conform to the destination array 243 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass(); 244 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass(); 245 if (stype == bound || stype->is_subtype_of(bound)) { 246 // elements are guaranteed to be subtypes, so no check necessary 247 bs->write_ref_array_pre(dst, length); 248 Copy::conjoint_oops_atomic(src, dst, length); 249 } else { 250 // slow case: need individual subtype checks 251 // note: don't use obj_at_put below because it includes a redundant store check 252 T* from = src; 253 T* end = from + length; 254 for (T* p = dst; from < end; from++, p++) { 255 // XXX this is going to be slow. 256 T element = *from; 257 // even slower now 258 bool element_is_null = oopDesc::is_null(element); 259 oop new_val = element_is_null ? oop(NULL) 260 : oopDesc::decode_heap_oop_not_null(element); 261 if (element_is_null || 262 (new_val->klass())->is_subtype_of(bound)) { 263 bs->write_ref_field_pre(p, new_val); 264 *p = element; 265 } else { 266 // We must do a barrier to cover the partial copy. 267 const size_t pd = pointer_delta(p, dst, (size_t)heapOopSize); 268 // pointer delta is scaled to number of elements (length field in 269 // objArrayOop) which we assume is 32 bit. 270 assert(pd == (size_t)(int)pd, "length field overflow"); 271 bs->write_ref_array((HeapWord*)dst, pd); 272 THROW(vmSymbols::java_lang_ArrayStoreException()); 273 return; 274 } 275 } 276 } 277 } 278 bs->write_ref_array((HeapWord*)dst, length); 279 } 280 281 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d, 282 int dst_pos, int length, TRAPS) { 283 assert(s->is_objArray(), "must be obj array"); 284 285 if (!d->is_objArray()) { 286 THROW(vmSymbols::java_lang_ArrayStoreException()); 287 } 288 289 // Check is all offsets and lengths are non negative 290 if (src_pos < 0 || dst_pos < 0 || length < 0) { 291 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException()); 292 } 293 // Check if the ranges are valid 294 if ( (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) 295 || (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length()) ) { 296 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException()); 297 } 298 299 // Special case. Boundary cases must be checked first 300 // This allows the following call: copy_array(s, s.length(), d.length(), 0). 301 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(), 302 // points to the right of the last element. 303 if (length==0) { 304 return; 305 } 306 if (UseCompressedOops) { 307 narrowOop* const src = objArrayOop(s)->obj_at_addr<narrowOop>(src_pos); 308 narrowOop* const dst = objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos); 309 do_copy<narrowOop>(s, src, d, dst, length, CHECK); 310 } else { 311 oop* const src = objArrayOop(s)->obj_at_addr<oop>(src_pos); 312 oop* const dst = objArrayOop(d)->obj_at_addr<oop>(dst_pos); 313 do_copy<oop> (s, src, d, dst, length, CHECK); 314 } 315 } 316 317 318 Klass* ObjArrayKlass::array_klass_impl(bool or_null, int n, TRAPS) { 319 320 assert(dimension() <= n, "check order of chain"); 321 int dim = dimension(); 322 if (dim == n) return this; 323 324 if (higher_dimension() == NULL) { 325 if (or_null) return NULL; 326 327 ResourceMark rm; 328 JavaThread *jt = (JavaThread *)THREAD; 329 { 330 MutexLocker mc(Compile_lock, THREAD); // for vtables 331 // Ensure atomic creation of higher dimensions 332 MutexLocker mu(MultiArray_lock, THREAD); 333 334 // Check if another thread beat us 335 if (higher_dimension() == NULL) { 336 337 // Create multi-dim klass object and link them together 338 Klass* k = 339 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL); 340 ObjArrayKlass* ak = ObjArrayKlass::cast(k); 341 ak->set_lower_dimension(this); 342 OrderAccess::storestore(); 343 set_higher_dimension(ak); 344 assert(ak->is_objArray_klass(), "incorrect initialization of ObjArrayKlass"); 345 } 346 } 347 } else { 348 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops()); 349 } 350 351 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension()); 352 if (or_null) { 353 return ak->array_klass_or_null(n); 354 } 355 return ak->array_klass(n, THREAD); 356 } 357 358 Klass* ObjArrayKlass::array_klass_impl(bool or_null, TRAPS) { 359 return array_klass_impl(or_null, dimension() + 1, THREAD); 360 } 361 362 bool ObjArrayKlass::can_be_primary_super_slow() const { 363 if (!bottom_klass()->can_be_primary_super()) 364 // array of interfaces 365 return false; 366 else 367 return Klass::can_be_primary_super_slow(); 368 } 369 370 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots) { 371 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... }; 372 Array<Klass*>* elem_supers = element_klass()->secondary_supers(); 373 int num_elem_supers = elem_supers == NULL ? 0 : elem_supers->length(); 374 int num_secondaries = num_extra_slots + 2 + num_elem_supers; 375 if (num_secondaries == 2) { 376 // Must share this for correct bootstrapping! 377 set_secondary_supers(Universe::the_array_interfaces_array()); 378 return NULL; 379 } else { 380 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2); 381 secondaries->push(SystemDictionary::Cloneable_klass()); 382 secondaries->push(SystemDictionary::Serializable_klass()); 383 for (int i = 0; i < num_elem_supers; i++) { 384 Klass* elem_super = (Klass*) elem_supers->at(i); 385 Klass* array_super = elem_super->array_klass_or_null(); 386 assert(array_super != NULL, "must already have been created"); 387 secondaries->push(array_super); 388 } 389 return secondaries; 390 } 391 } 392 393 bool ObjArrayKlass::compute_is_subtype_of(Klass* k) { 394 if (!k->is_objArray_klass()) 395 return ArrayKlass::compute_is_subtype_of(k); 396 397 ObjArrayKlass* oak = ObjArrayKlass::cast(k); 398 return element_klass()->is_subtype_of(oak->element_klass()); 399 } 400 401 void ObjArrayKlass::initialize(TRAPS) { 402 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass 403 } 404 405 // JVM support 406 407 jint ObjArrayKlass::compute_modifier_flags(TRAPS) const { 408 // The modifier for an objectArray is the same as its element 409 if (element_klass() == NULL) { 410 assert(Universe::is_bootstrapping(), "partial objArray only at startup"); 411 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 412 } 413 // Return the flags of the bottom element type. 414 jint element_flags = bottom_klass()->compute_modifier_flags(CHECK_0); 415 416 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED)) 417 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL); 418 } 419 420 ModuleEntry* ObjArrayKlass::module() const { 421 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass"); 422 // The array is defined in the module of its bottom class 423 return bottom_klass()->module(); 424 } 425 426 PackageEntry* ObjArrayKlass::package() const { 427 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass"); 428 return bottom_klass()->package(); 429 } 430 431 // Printing 432 433 void ObjArrayKlass::print_on(outputStream* st) const { 434 #ifndef PRODUCT 435 Klass::print_on(st); 436 st->print(" - instance klass: "); 437 element_klass()->print_value_on(st); 438 st->cr(); 439 #endif //PRODUCT 440 } 441 442 void ObjArrayKlass::print_value_on(outputStream* st) const { 443 assert(is_klass(), "must be klass"); 444 445 element_klass()->print_value_on(st); 446 st->print("[]"); 447 } 448 449 #ifndef PRODUCT 450 451 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) { 452 ArrayKlass::oop_print_on(obj, st); 453 assert(obj->is_objArray(), "must be objArray"); 454 objArrayOop oa = objArrayOop(obj); 455 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize); 456 for(int index = 0; index < print_len; index++) { 457 st->print(" - %3d : ", index); 458 oa->obj_at(index)->print_value_on(st); 459 st->cr(); 460 } 461 int remaining = oa->length() - print_len; 462 if (remaining > 0) { 463 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining); 464 } 465 } 466 467 #endif //PRODUCT 468 469 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) { 470 assert(obj->is_objArray(), "must be objArray"); 471 st->print("a "); 472 element_klass()->print_value_on(st); 473 int len = objArrayOop(obj)->length(); 474 st->print("[%d] ", len); 475 obj->print_address_on(st); 476 } 477 478 const char* ObjArrayKlass::internal_name() const { 479 return external_name(); 480 } 481 482 483 // Verification 484 485 void ObjArrayKlass::verify_on(outputStream* st) { 486 ArrayKlass::verify_on(st); 487 guarantee(element_klass()->is_klass(), "should be klass"); 488 guarantee(bottom_klass()->is_klass(), "should be klass"); 489 Klass* bk = bottom_klass(); 490 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass(), "invalid bottom klass"); 491 } 492 493 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) { 494 ArrayKlass::oop_verify_on(obj, st); 495 guarantee(obj->is_objArray(), "must be objArray"); 496 objArrayOop oa = objArrayOop(obj); 497 for(int index = 0; index < oa->length(); index++) { 498 guarantee(oa->obj_at(index)->is_oop_or_null(), "should be oop"); 499 } 500 }