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