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/oopFactory.hpp" 37 #include "memory/resourceArea.hpp" 38 #include "memory/universe.inline.hpp" 39 #include "oops/arrayKlass.inline.hpp" 40 #include "oops/instanceKlass.hpp" 41 #include "oops/klass.inline.hpp" 42 #include "oops/objArrayKlass.inline.hpp" 43 #include "oops/objArrayOop.inline.hpp" 44 #include "oops/oop.inline.hpp" 45 #include "oops/symbol.hpp" 46 #include "runtime/handles.inline.hpp" 47 #include "runtime/mutexLocker.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 = ArrayKlass::create_element_klass_array_name(element_klass, CHECK_NULL); 104 105 // Initialize instance variables 106 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_0); 107 108 // Add all classes to our internal class loader list here, 109 // including classes in the bootstrap (NULL) class loader. 110 // GC walks these as strong roots. 111 loader_data->add_class(oak); 112 113 ModuleEntry* module = oak->module(); 114 assert(module != NULL, "No module entry for array"); 115 116 // Call complete_create_array_klass after all instance variables has been initialized. 117 ArrayKlass::complete_create_array_klass(oak, super_klass, module, CHECK_0); 118 119 return oak; 120 } 121 122 ObjArrayKlass::ObjArrayKlass(int n, Klass* element_klass, Symbol* name) : ArrayKlass(name) { 123 this->set_dimension(n); 124 this->set_element_klass(element_klass); 125 // decrement refcount because object arrays are not explicitly freed. The 126 // InstanceKlass array_name() keeps the name counted while the klass is 127 // loaded. 128 name->decrement_refcount(); 129 130 Klass* bk; 131 if (element_klass->is_objArray_klass()) { 132 bk = ObjArrayKlass::cast(element_klass)->bottom_klass(); 133 } else { 134 bk = element_klass; 135 } 136 assert(bk != NULL && (bk->is_instance_klass() 137 || bk->is_typeArray_klass() 138 || bk->is_valueArray_klass()), "invalid bottom klass"); 139 this->set_bottom_klass(bk); 140 this->set_class_loader_data(bk->class_loader_data()); 141 142 this->set_layout_helper(array_layout_helper(T_OBJECT)); 143 assert(this->is_array_klass(), "sanity"); 144 assert(this->is_objArray_klass(), "sanity"); 145 } 146 147 int ObjArrayKlass::oop_size(oop obj) const { 148 assert(obj->is_objArray(), "must be object array"); 149 return objArrayOop(obj)->object_size(); 150 } 151 152 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) { 153 if (length >= 0) { 154 if (length <= arrayOopDesc::max_array_length(T_OBJECT)) { 155 int size = objArrayOopDesc::object_size(length); 156 return (objArrayOop)CollectedHeap::array_allocate(this, size, length, THREAD); 157 } else { 158 report_java_out_of_memory("Requested array size exceeds VM limit"); 159 JvmtiExport::post_array_size_exhausted(); 160 THROW_OOP_0(Universe::out_of_memory_error_array_size()); 161 } 162 } else { 163 THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 164 } 165 } 166 167 static int multi_alloc_counter = 0; 168 169 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) { 170 int length = *sizes; 171 if (rank == 1) { // last dim may be valueArray 172 return oopFactory::new_array(element_klass(), length, CHECK_NULL); 173 } 174 guarantee(rank > 1, "Rank below 1"); 175 // Call to lower_dimension uses this pointer, so most be called before a 176 // possible GC 177 Klass* ld_klass = lower_dimension(); 178 // If length < 0 allocate will throw an exception. 179 objArrayOop array = allocate(length, CHECK_NULL); 180 objArrayHandle h_array (THREAD, array); 181 if (length != 0) { 182 for (int index = 0; index < length; index++) { 183 ArrayKlass* ak = ArrayKlass::cast(ld_klass); 184 oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL); 185 h_array->obj_at_put(index, sub_array); 186 } 187 } else { 188 // Since this array dimension has zero length, nothing will be 189 // allocated, however the lower dimension values must be checked 190 // for illegal values. 191 for (int i = 0; i < rank - 1; ++i) { 192 sizes += 1; 193 if (*sizes < 0) { 194 THROW_0(vmSymbols::java_lang_NegativeArraySizeException()); 195 } 196 } 197 } 198 return h_array(); 199 } 200 201 // Either oop or narrowOop depending on UseCompressedOops. 202 template <class T> void ObjArrayKlass::do_copy(arrayOop s, T* src, 203 arrayOop d, T* dst, int length, TRAPS) { 204 if (s == d) { 205 // since source and destination are equal we do not need conversion checks. 206 assert(length > 0, "sanity check"); 207 HeapAccess<>::oop_arraycopy(s, d, src, dst, length); 208 } else { 209 // We have to make sure all elements conform to the destination array 210 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass(); 211 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass(); 212 if (stype == bound || stype->is_subtype_of(bound)) { 213 // elements are guaranteed to be subtypes, so no check necessary 214 HeapAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, d, src, dst, length); 215 } else { 216 // slow case: need individual subtype checks 217 // note: don't use obj_at_put below because it includes a redundant store check 218 if (!HeapAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, d, src, dst, length)) { 219 THROW(vmSymbols::java_lang_ArrayStoreException()); 220 } 221 } 222 } 223 } 224 225 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d, 226 int dst_pos, int length, TRAPS) { 227 assert(s->is_objArray(), "must be obj array"); 228 229 if (!d->is_objArray()) { 230 THROW(vmSymbols::java_lang_ArrayStoreException()); 231 } 232 233 // Check is all offsets and lengths are non negative 234 if (src_pos < 0 || dst_pos < 0 || length < 0) { 235 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException()); 236 } 237 // Check if the ranges are valid 238 if ( (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length()) 239 || (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length()) ) { 240 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException()); 241 } 242 243 // Special case. Boundary cases must be checked first 244 // This allows the following call: copy_array(s, s.length(), d.length(), 0). 245 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(), 246 // points to the right of the last element. 247 if (length==0) { 248 return; 249 } 250 if (UseCompressedOops) { 251 narrowOop* const src = objArrayOop(s)->obj_at_addr<narrowOop>(src_pos); 252 narrowOop* const dst = objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos); 253 do_copy<narrowOop>(s, src, d, dst, length, CHECK); 254 } else { 255 oop* const src = objArrayOop(s)->obj_at_addr<oop>(src_pos); 256 oop* const dst = objArrayOop(d)->obj_at_addr<oop>(dst_pos); 257 do_copy<oop> (s, src, d, dst, length, CHECK); 258 } 259 } 260 261 262 Klass* ObjArrayKlass::array_klass_impl(bool or_null, int n, TRAPS) { 263 264 assert(dimension() <= n, "check order of chain"); 265 int dim = dimension(); 266 if (dim == n) return this; 267 268 // lock-free read needs acquire semantics 269 if (higher_dimension_acquire() == NULL) { 270 if (or_null) return NULL; 271 272 ResourceMark rm; 273 JavaThread *jt = (JavaThread *)THREAD; 274 { 275 MutexLocker mc(Compile_lock, THREAD); // for vtables 276 // Ensure atomic creation of higher dimensions 277 MutexLocker mu(MultiArray_lock, THREAD); 278 279 // Check if another thread beat us 280 if (higher_dimension() == NULL) { 281 282 // Create multi-dim klass object and link them together 283 Klass* k = 284 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL); 285 ObjArrayKlass* ak = ObjArrayKlass::cast(k); 286 ak->set_lower_dimension(this); 287 // use 'release' to pair with lock-free load 288 release_set_higher_dimension(ak); 289 assert(ak->is_objArray_klass(), "incorrect initialization of ObjArrayKlass"); 290 } 291 } 292 } else { 293 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops()); 294 } 295 296 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension()); 297 if (or_null) { 298 return ak->array_klass_or_null(n); 299 } 300 return ak->array_klass(n, THREAD); 301 } 302 303 Klass* ObjArrayKlass::array_klass_impl(bool or_null, TRAPS) { 304 return array_klass_impl(or_null, dimension() + 1, THREAD); 305 } 306 307 bool ObjArrayKlass::can_be_primary_super_slow() const { 308 if (!bottom_klass()->can_be_primary_super()) 309 // array of interfaces 310 return false; 311 else 312 return Klass::can_be_primary_super_slow(); 313 } 314 315 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots) { 316 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... }; 317 Array<Klass*>* elem_supers = element_klass()->secondary_supers(); 318 int num_elem_supers = elem_supers == NULL ? 0 : elem_supers->length(); 319 int num_secondaries = num_extra_slots + 2 + num_elem_supers; 320 if (num_secondaries == 2) { 321 // Must share this for correct bootstrapping! 322 set_secondary_supers(Universe::the_array_interfaces_array()); 323 return NULL; 324 } else { 325 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2); 326 secondaries->push(SystemDictionary::Cloneable_klass()); 327 secondaries->push(SystemDictionary::Serializable_klass()); 328 for (int i = 0; i < num_elem_supers; i++) { 329 Klass* elem_super = (Klass*) elem_supers->at(i); 330 Klass* array_super = elem_super->array_klass_or_null(); 331 assert(array_super != NULL, "must already have been created"); 332 secondaries->push(array_super); 333 } 334 return secondaries; 335 } 336 } 337 338 bool ObjArrayKlass::compute_is_subtype_of(Klass* k) { 339 if (!k->is_objArray_klass()) 340 return ArrayKlass::compute_is_subtype_of(k); 341 342 ObjArrayKlass* oak = ObjArrayKlass::cast(k); 343 return element_klass()->is_subtype_of(oak->element_klass()); 344 } 345 346 void ObjArrayKlass::initialize(TRAPS) { 347 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass 348 } 349 350 void ObjArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) { 351 ArrayKlass::metaspace_pointers_do(it); 352 it->push(&_element_klass); 353 it->push(&_bottom_klass); 354 } 355 356 // JVM support 357 358 jint ObjArrayKlass::compute_modifier_flags(TRAPS) const { 359 // The modifier for an objectArray is the same as its element 360 if (element_klass() == NULL) { 361 assert(Universe::is_bootstrapping(), "partial objArray only at startup"); 362 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC; 363 } 364 // Return the flags of the bottom element type. 365 jint element_flags = bottom_klass()->compute_modifier_flags(CHECK_0); 366 367 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED)) 368 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL); 369 } 370 371 ModuleEntry* ObjArrayKlass::module() const { 372 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass"); 373 // The array is defined in the module of its bottom class 374 return bottom_klass()->module(); 375 } 376 377 PackageEntry* ObjArrayKlass::package() const { 378 assert(bottom_klass() != NULL, "ObjArrayKlass returned unexpected NULL bottom_klass"); 379 return bottom_klass()->package(); 380 } 381 382 // Printing 383 384 void ObjArrayKlass::print_on(outputStream* st) const { 385 #ifndef PRODUCT 386 Klass::print_on(st); 387 st->print(" - element klass: "); 388 element_klass()->print_value_on(st); 389 st->cr(); 390 #endif //PRODUCT 391 } 392 393 void ObjArrayKlass::print_value_on(outputStream* st) const { 394 assert(is_klass(), "must be klass"); 395 396 element_klass()->print_value_on(st); 397 st->print("[]"); 398 } 399 400 #ifndef PRODUCT 401 402 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) { 403 ArrayKlass::oop_print_on(obj, st); 404 assert(obj->is_objArray(), "must be objArray"); 405 objArrayOop oa = objArrayOop(obj); 406 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize); 407 for(int index = 0; index < print_len; index++) { 408 st->print(" - %3d : ", index); 409 oa->obj_at(index)->print_value_on(st); 410 st->cr(); 411 } 412 int remaining = oa->length() - print_len; 413 if (remaining > 0) { 414 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining); 415 } 416 } 417 418 #endif //PRODUCT 419 420 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) { 421 assert(obj->is_objArray(), "must be objArray"); 422 st->print("a "); 423 element_klass()->print_value_on(st); 424 int len = objArrayOop(obj)->length(); 425 st->print("[%d] ", len); 426 obj->print_address_on(st); 427 } 428 429 const char* ObjArrayKlass::internal_name() const { 430 return external_name(); 431 } 432 433 434 // Verification 435 436 void ObjArrayKlass::verify_on(outputStream* st) { 437 ArrayKlass::verify_on(st); 438 guarantee(element_klass()->is_klass(), "should be klass"); 439 guarantee(bottom_klass()->is_klass(), "should be klass"); 440 Klass* bk = bottom_klass(); 441 guarantee(bk->is_instance_klass() || bk->is_typeArray_klass() || bk->is_valueArray_klass(), 442 "invalid bottom klass"); 443 } 444 445 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) { 446 ArrayKlass::oop_verify_on(obj, st); 447 guarantee(obj->is_objArray(), "must be objArray"); 448 objArrayOop oa = objArrayOop(obj); 449 for(int index = 0; index < oa->length(); index++) { 450 guarantee(oopDesc::is_oop_or_null(oa->obj_at(index)), "should be oop"); 451 } 452 }