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 #ifndef SHARE_VM_OOPS_OOP_INLINE_HPP 26 #define SHARE_VM_OOPS_OOP_INLINE_HPP 27 28 #include "gc_implementation/shared/ageTable.hpp" 29 #include "gc_implementation/shared/markSweep.inline.hpp" 30 #include "gc_interface/collectedHeap.inline.hpp" 31 #include "memory/barrierSet.inline.hpp" 32 #include "memory/cardTableModRefBS.hpp" 33 #include "memory/genCollectedHeap.hpp" 34 #include "memory/generation.hpp" 35 #include "memory/specialized_oop_closures.hpp" 36 #include "oops/arrayKlass.hpp" 37 #include "oops/arrayOop.hpp" 38 #include "oops/klass.inline.hpp" 39 #include "oops/markOop.inline.hpp" 40 #include "oops/oop.hpp" 41 #include "runtime/atomic.inline.hpp" 42 #include "runtime/orderAccess.inline.hpp" 43 #include "runtime/os.hpp" 44 #include "utilities/macros.hpp" 45 #ifdef TARGET_ARCH_x86 46 # include "bytes_x86.hpp" 47 #endif 48 #ifdef TARGET_ARCH_sparc 49 # include "bytes_sparc.hpp" 50 #endif 51 #ifdef TARGET_ARCH_zero 52 # include "bytes_zero.hpp" 53 #endif 54 #ifdef TARGET_ARCH_arm 55 # include "bytes_arm.hpp" 56 #endif 57 #ifdef TARGET_ARCH_ppc 58 # include "bytes_ppc.hpp" 59 #endif 60 61 // Implementation of all inlined member functions defined in oop.hpp 62 // We need a separate file to avoid circular references 63 64 inline void oopDesc::release_set_mark(markOop m) { 65 OrderAccess::release_store_ptr(&_mark, m); 66 } 67 68 inline markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) { 69 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark); 70 } 71 72 inline Klass* oopDesc::klass() const { 73 if (UseCompressedClassPointers) { 74 return Klass::decode_klass_not_null(_metadata._compressed_klass); 75 } else { 76 return _metadata._klass; 77 } 78 } 79 80 inline Klass* oopDesc::klass_or_null() const volatile { 81 if (UseCompressedClassPointers) { 82 return Klass::decode_klass(_metadata._compressed_klass); 83 } else { 84 return _metadata._klass; 85 } 86 } 87 88 inline Klass* oopDesc::klass_or_null_acquire() const volatile { 89 if (UseCompressedClassPointers) { 90 // Workaround for non-const load_acquire parameter. 91 const volatile narrowKlass* addr = &_metadata._compressed_klass; 92 volatile narrowKlass* xaddr = const_cast<volatile narrowKlass*>(addr); 93 return Klass::decode_klass(OrderAccess::load_acquire(xaddr)); 94 } else { 95 return (Klass*)OrderAccess::load_ptr_acquire(&_metadata._klass); 96 } 97 } 98 99 inline int oopDesc::klass_gap_offset_in_bytes() { 100 assert(UseCompressedClassPointers, "only applicable to compressed klass pointers"); 101 return oopDesc::klass_offset_in_bytes() + sizeof(narrowKlass); 102 } 103 104 inline Klass** oopDesc::klass_addr() { 105 // Only used internally and with CMS and will not work with 106 // UseCompressedOops 107 assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers"); 108 return (Klass**) &_metadata._klass; 109 } 110 111 inline narrowKlass* oopDesc::compressed_klass_addr() { 112 assert(UseCompressedClassPointers, "only called by compressed klass pointers"); 113 return &_metadata._compressed_klass; 114 } 115 116 #define CHECK_SET_KLASS(k) \ 117 do { \ 118 assert(Universe::is_bootstrapping() || k != NULL, "NULL Klass"); \ 119 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass"); \ 120 } while (0) 121 122 inline void oopDesc::set_klass(Klass* k) { 123 CHECK_SET_KLASS(k); 124 if (UseCompressedClassPointers) { 125 *compressed_klass_addr() = Klass::encode_klass_not_null(k); 126 } else { 127 *klass_addr() = k; 128 } 129 } 130 131 inline void oopDesc::release_set_klass(Klass* k) { 132 CHECK_SET_KLASS(k); 133 if (UseCompressedClassPointers) { 134 OrderAccess::release_store(compressed_klass_addr(), 135 Klass::encode_klass_not_null(k)); 136 } else { 137 OrderAccess::release_store_ptr(klass_addr(), k); 138 } 139 } 140 141 #undef CHECK_SET_KLASS 142 143 inline int oopDesc::klass_gap() const { 144 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()); 145 } 146 147 inline void oopDesc::set_klass_gap(int v) { 148 if (UseCompressedClassPointers) { 149 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v; 150 } 151 } 152 153 inline void oopDesc::set_klass_to_list_ptr(oop k) { 154 // This is only to be used during GC, for from-space objects, so no 155 // barrier is needed. 156 if (UseCompressedClassPointers) { 157 _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k); // may be null (parnew overflow handling) 158 } else { 159 _metadata._klass = (Klass*)(address)k; 160 } 161 } 162 163 inline oop oopDesc::list_ptr_from_klass() { 164 // This is only to be used during GC, for from-space objects. 165 if (UseCompressedClassPointers) { 166 return decode_heap_oop((narrowOop)_metadata._compressed_klass); 167 } else { 168 // Special case for GC 169 return (oop)(address)_metadata._klass; 170 } 171 } 172 173 inline void oopDesc::init_mark() { set_mark(markOopDesc::prototype_for_object(this)); } 174 175 inline bool oopDesc::is_a(Klass* k) const { return klass()->is_subtype_of(k); } 176 177 inline bool oopDesc::is_instance() const { return klass()->oop_is_instance(); } 178 inline bool oopDesc::is_instanceClassLoader() const { return klass()->oop_is_instanceClassLoader(); } 179 inline bool oopDesc::is_instanceMirror() const { return klass()->oop_is_instanceMirror(); } 180 inline bool oopDesc::is_instanceRef() const { return klass()->oop_is_instanceRef(); } 181 inline bool oopDesc::is_array() const { return klass()->oop_is_array(); } 182 inline bool oopDesc::is_objArray() const { return klass()->oop_is_objArray(); } 183 inline bool oopDesc::is_typeArray() const { return klass()->oop_is_typeArray(); } 184 185 inline void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; } 186 187 template <class T> inline T* oopDesc::obj_field_addr(int offset) const { return (T*)field_base(offset); } 188 inline Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); } 189 inline jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); } 190 inline jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); } 191 inline jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*)field_base(offset); } 192 inline jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); } 193 inline jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); } 194 inline jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); } 195 inline jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); } 196 inline jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); } 197 inline address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); } 198 199 200 // Functions for getting and setting oops within instance objects. 201 // If the oops are compressed, the type passed to these overloaded functions 202 // is narrowOop. All functions are overloaded so they can be called by 203 // template functions without conditionals (the compiler instantiates via 204 // the right type and inlines the appopriate code). 205 206 inline bool oopDesc::is_null(oop obj) { return obj == NULL; } 207 inline bool oopDesc::is_null(narrowOop obj) { return obj == 0; } 208 209 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit 210 // offset from the heap base. Saving the check for null can save instructions 211 // in inner GC loops so these are separated. 212 213 inline bool check_obj_alignment(oop obj) { 214 return cast_from_oop<intptr_t>(obj) % MinObjAlignmentInBytes == 0; 215 } 216 217 inline narrowOop oopDesc::encode_heap_oop_not_null(oop v) { 218 assert(!is_null(v), "oop value can never be zero"); 219 assert(check_obj_alignment(v), "Address not aligned"); 220 assert(Universe::heap()->is_in_reserved(v), "Address not in heap"); 221 address base = Universe::narrow_oop_base(); 222 int shift = Universe::narrow_oop_shift(); 223 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1)); 224 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding"); 225 uint64_t result = pd >> shift; 226 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow"); 227 assert(decode_heap_oop(result) == v, "reversibility"); 228 return (narrowOop)result; 229 } 230 231 inline narrowOop oopDesc::encode_heap_oop(oop v) { 232 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v); 233 } 234 235 inline oop oopDesc::decode_heap_oop_not_null(narrowOop v) { 236 assert(!is_null(v), "narrow oop value can never be zero"); 237 address base = Universe::narrow_oop_base(); 238 int shift = Universe::narrow_oop_shift(); 239 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift)); 240 assert(check_obj_alignment(result), err_msg("address not aligned: " INTPTR_FORMAT, p2i((void*) result))); 241 return result; 242 } 243 244 inline oop oopDesc::decode_heap_oop(narrowOop v) { 245 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v); 246 } 247 248 inline oop oopDesc::decode_heap_oop_not_null(oop v) { return v; } 249 inline oop oopDesc::decode_heap_oop(oop v) { return v; } 250 251 // Load an oop out of the Java heap as is without decoding. 252 // Called by GC to check for null before decoding. 253 inline oop oopDesc::load_heap_oop(oop* p) { return *p; } 254 inline narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; } 255 256 // Load and decode an oop out of the Java heap into a wide oop. 257 inline oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; } 258 inline oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) { 259 return decode_heap_oop_not_null(*p); 260 } 261 262 // Load and decode an oop out of the heap accepting null 263 inline oop oopDesc::load_decode_heap_oop(oop* p) { return *p; } 264 inline oop oopDesc::load_decode_heap_oop(narrowOop* p) { 265 return decode_heap_oop(*p); 266 } 267 268 // Store already encoded heap oop into the heap. 269 inline void oopDesc::store_heap_oop(oop* p, oop v) { *p = v; } 270 inline void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; } 271 272 // Encode and store a heap oop. 273 inline void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) { 274 *p = encode_heap_oop_not_null(v); 275 } 276 inline void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; } 277 278 // Encode and store a heap oop allowing for null. 279 inline void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) { 280 *p = encode_heap_oop(v); 281 } 282 inline void oopDesc::encode_store_heap_oop(oop* p, oop v) { *p = v; } 283 284 // Store heap oop as is for volatile fields. 285 inline void oopDesc::release_store_heap_oop(volatile oop* p, oop v) { 286 OrderAccess::release_store_ptr(p, v); 287 } 288 inline void oopDesc::release_store_heap_oop(volatile narrowOop* p, 289 narrowOop v) { 290 OrderAccess::release_store(p, v); 291 } 292 293 inline void oopDesc::release_encode_store_heap_oop_not_null( 294 volatile narrowOop* p, oop v) { 295 // heap oop is not pointer sized. 296 OrderAccess::release_store(p, encode_heap_oop_not_null(v)); 297 } 298 299 inline void oopDesc::release_encode_store_heap_oop_not_null( 300 volatile oop* p, oop v) { 301 OrderAccess::release_store_ptr(p, v); 302 } 303 304 inline void oopDesc::release_encode_store_heap_oop(volatile oop* p, 305 oop v) { 306 OrderAccess::release_store_ptr(p, v); 307 } 308 inline void oopDesc::release_encode_store_heap_oop( 309 volatile narrowOop* p, oop v) { 310 OrderAccess::release_store(p, encode_heap_oop(v)); 311 } 312 313 314 // These functions are only used to exchange oop fields in instances, 315 // not headers. 316 inline oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) { 317 if (UseCompressedOops) { 318 // encode exchange value from oop to T 319 narrowOop val = encode_heap_oop(exchange_value); 320 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest); 321 // decode old from T to oop 322 return decode_heap_oop(old); 323 } else { 324 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest); 325 } 326 } 327 328 // In order to put or get a field out of an instance, must first check 329 // if the field has been compressed and uncompress it. 330 inline oop oopDesc::obj_field(int offset) const { 331 return UseCompressedOops ? 332 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) : 333 load_decode_heap_oop(obj_field_addr<oop>(offset)); 334 } 335 inline volatile oop oopDesc::obj_field_volatile(int offset) const { 336 volatile oop value = obj_field(offset); 337 OrderAccess::acquire(); 338 return value; 339 } 340 inline void oopDesc::obj_field_put(int offset, oop value) { 341 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) : 342 oop_store(obj_field_addr<oop>(offset), value); 343 } 344 345 inline Metadata* oopDesc::metadata_field(int offset) const { 346 return *metadata_field_addr(offset); 347 } 348 349 inline void oopDesc::metadata_field_put(int offset, Metadata* value) { 350 *metadata_field_addr(offset) = value; 351 } 352 353 inline void oopDesc::obj_field_put_raw(int offset, oop value) { 354 UseCompressedOops ? 355 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) : 356 encode_store_heap_oop(obj_field_addr<oop>(offset), value); 357 } 358 inline void oopDesc::obj_field_put_volatile(int offset, oop value) { 359 OrderAccess::release(); 360 obj_field_put(offset, value); 361 OrderAccess::fence(); 362 } 363 364 inline jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); } 365 inline void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; } 366 367 inline jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); } 368 inline void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (( (jint) contents) & 1); } 369 370 inline jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); } 371 inline void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; } 372 373 inline jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); } 374 inline void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; } 375 376 inline jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); } 377 inline void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;} 378 379 inline jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); } 380 inline void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; } 381 382 inline jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); } 383 inline void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; } 384 385 inline jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); } 386 inline void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; } 387 388 inline address oopDesc::address_field(int offset) const { return *address_field_addr(offset); } 389 inline void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; } 390 391 inline oop oopDesc::obj_field_acquire(int offset) const { 392 return UseCompressedOops ? 393 decode_heap_oop((narrowOop) 394 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset))) 395 : decode_heap_oop((oop) 396 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset))); 397 } 398 inline void oopDesc::release_obj_field_put(int offset, oop value) { 399 UseCompressedOops ? 400 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) : 401 oop_store((volatile oop*) obj_field_addr<oop>(offset), value); 402 } 403 404 inline jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); } 405 inline void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); } 406 407 inline jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); } 408 inline void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), (contents & 1)); } 409 410 inline jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); } 411 inline void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); } 412 413 inline jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); } 414 inline void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); } 415 416 inline jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); } 417 inline void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); } 418 419 inline jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); } 420 inline void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); } 421 422 inline jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); } 423 inline void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); } 424 425 inline jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); } 426 inline void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); } 427 428 inline address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); } 429 inline void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); } 430 431 inline int oopDesc::size_given_klass(Klass* klass) { 432 int lh = klass->layout_helper(); 433 int s; 434 435 // lh is now a value computed at class initialization that may hint 436 // at the size. For instances, this is positive and equal to the 437 // size. For arrays, this is negative and provides log2 of the 438 // array element size. For other oops, it is zero and thus requires 439 // a virtual call. 440 // 441 // We go to all this trouble because the size computation is at the 442 // heart of phase 2 of mark-compaction, and called for every object, 443 // alive or dead. So the speed here is equal in importance to the 444 // speed of allocation. 445 446 if (lh > Klass::_lh_neutral_value) { 447 if (!Klass::layout_helper_needs_slow_path(lh)) { 448 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize 449 } else { 450 s = klass->oop_size(this); 451 } 452 } else if (lh <= Klass::_lh_neutral_value) { 453 // The most common case is instances; fall through if so. 454 if (lh < Klass::_lh_neutral_value) { 455 // Second most common case is arrays. We have to fetch the 456 // length of the array, shift (multiply) it appropriately, 457 // up to wordSize, add the header, and align to object size. 458 size_t size_in_bytes; 459 #ifdef _M_IA64 460 // The Windows Itanium Aug 2002 SDK hoists this load above 461 // the check for s < 0. An oop at the end of the heap will 462 // cause an access violation if this load is performed on a non 463 // array oop. Making the reference volatile prohibits this. 464 // (%%% please explain by what magic the length is actually fetched!) 465 volatile int *array_length; 466 array_length = (volatile int *)( (intptr_t)this + 467 arrayOopDesc::length_offset_in_bytes() ); 468 assert(array_length > 0, "Integer arithmetic problem somewhere"); 469 // Put into size_t to avoid overflow. 470 size_in_bytes = (size_t) array_length; 471 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh); 472 #else 473 size_t array_length = (size_t) ((arrayOop)this)->length(); 474 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh); 475 #endif 476 size_in_bytes += Klass::layout_helper_header_size(lh); 477 478 // This code could be simplified, but by keeping array_header_in_bytes 479 // in units of bytes and doing it this way we can round up just once, 480 // skipping the intermediate round to HeapWordSize. Cast the result 481 // of round_to to size_t to guarantee unsigned division == right shift. 482 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) / 483 HeapWordSize); 484 485 // UseParNewGC, UseParallelGC and UseG1GC can change the length field 486 // of an "old copy" of an object array in the young gen so it indicates 487 // the grey portion of an already copied array. This will cause the first 488 // disjunct below to fail if the two comparands are computed across such 489 // a concurrent change. 490 // UseParNewGC also runs with promotion labs (which look like int 491 // filler arrays) which are subject to changing their declared size 492 // when finally retiring a PLAB; this also can cause the first disjunct 493 // to fail for another worker thread that is concurrently walking the block 494 // offset table. Both these invariant failures are benign for their 495 // current uses; we relax the assertion checking to cover these two cases below: 496 // is_objArray() && is_forwarded() // covers first scenario above 497 // || is_typeArray() // covers second scenario above 498 // If and when UseParallelGC uses the same obj array oop stealing/chunking 499 // technique, we will need to suitably modify the assertion. 500 assert((s == klass->oop_size(this)) || 501 (Universe::heap()->is_gc_active() && 502 ((is_typeArray() && UseParNewGC) || 503 (is_objArray() && is_forwarded() && (UseParNewGC || UseParallelGC || UseG1GC)))), 504 "wrong array object size"); 505 } else { 506 // Must be zero, so bite the bullet and take the virtual call. 507 s = klass->oop_size(this); 508 } 509 } 510 511 assert(s % MinObjAlignment == 0, "alignment check"); 512 assert(s > 0, "Bad size calculated"); 513 return s; 514 } 515 516 517 inline int oopDesc::size() { 518 return size_given_klass(klass()); 519 } 520 521 inline void update_barrier_set(void* p, oop v, bool release = false) { 522 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!"); 523 oopDesc::bs()->write_ref_field(p, v, release); 524 } 525 526 template <class T> inline void update_barrier_set_pre(T* p, oop v) { 527 oopDesc::bs()->write_ref_field_pre(p, v); 528 } 529 530 template <class T> inline void oop_store(T* p, oop v) { 531 if (always_do_update_barrier) { 532 oop_store((volatile T*)p, v); 533 } else { 534 update_barrier_set_pre(p, v); 535 oopDesc::encode_store_heap_oop(p, v); 536 // always_do_update_barrier == false => 537 // Either we are at a safepoint (in GC) or CMS is not used. In both 538 // cases it's unnecessary to mark the card as dirty with release sematics. 539 update_barrier_set((void*)p, v, false /* release */); // cast away type 540 } 541 } 542 543 template <class T> inline void oop_store(volatile T* p, oop v) { 544 update_barrier_set_pre((T*)p, v); // cast away volatile 545 // Used by release_obj_field_put, so use release_store_ptr. 546 oopDesc::release_encode_store_heap_oop(p, v); 547 // When using CMS we must mark the card corresponding to p as dirty 548 // with release sematics to prevent that CMS sees the dirty card but 549 // not the new value v at p due to reordering of the two 550 // stores. Note that CMS has a concurrent precleaning phase, where 551 // it reads the card table while the Java threads are running. 552 update_barrier_set((void*)p, v, true /* release */); // cast away type 553 } 554 555 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops 556 // (without having to remember the function name this calls). 557 inline void oop_store_raw(HeapWord* addr, oop value) { 558 if (UseCompressedOops) { 559 oopDesc::encode_store_heap_oop((narrowOop*)addr, value); 560 } else { 561 oopDesc::encode_store_heap_oop((oop*)addr, value); 562 } 563 } 564 565 inline oop oopDesc::atomic_compare_exchange_oop(oop exchange_value, 566 volatile HeapWord *dest, 567 oop compare_value, 568 bool prebarrier) { 569 if (UseCompressedOops) { 570 if (prebarrier) { 571 update_barrier_set_pre((narrowOop*)dest, exchange_value); 572 } 573 // encode exchange and compare value from oop to T 574 narrowOop val = encode_heap_oop(exchange_value); 575 narrowOop cmp = encode_heap_oop(compare_value); 576 577 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp); 578 // decode old from T to oop 579 return decode_heap_oop(old); 580 } else { 581 if (prebarrier) { 582 update_barrier_set_pre((oop*)dest, exchange_value); 583 } 584 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value); 585 } 586 } 587 588 // Used only for markSweep, scavenging 589 inline bool oopDesc::is_gc_marked() const { 590 return mark()->is_marked(); 591 } 592 593 inline bool oopDesc::is_locked() const { 594 return mark()->is_locked(); 595 } 596 597 inline bool oopDesc::is_unlocked() const { 598 return mark()->is_unlocked(); 599 } 600 601 inline bool oopDesc::has_bias_pattern() const { 602 return mark()->has_bias_pattern(); 603 } 604 605 606 // used only for asserts 607 inline bool oopDesc::is_oop(bool ignore_mark_word) const { 608 oop obj = (oop) this; 609 if (!check_obj_alignment(obj)) return false; 610 if (!Universe::heap()->is_in_reserved(obj)) return false; 611 // obj is aligned and accessible in heap 612 if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false; 613 614 // Header verification: the mark is typically non-NULL. If we're 615 // at a safepoint, it must not be null. 616 // Outside of a safepoint, the header could be changing (for example, 617 // another thread could be inflating a lock on this object). 618 if (ignore_mark_word) { 619 return true; 620 } 621 if (mark() != NULL) { 622 return true; 623 } 624 return !SafepointSynchronize::is_at_safepoint(); 625 } 626 627 628 // used only for asserts 629 inline bool oopDesc::is_oop_or_null(bool ignore_mark_word) const { 630 return this == NULL ? true : is_oop(ignore_mark_word); 631 } 632 633 #ifndef PRODUCT 634 // used only for asserts 635 inline bool oopDesc::is_unlocked_oop() const { 636 if (!Universe::heap()->is_in_reserved(this)) return false; 637 return mark()->is_unlocked(); 638 } 639 #endif // PRODUCT 640 641 inline void oopDesc::follow_contents(void) { 642 assert (is_gc_marked(), "should be marked"); 643 klass()->oop_follow_contents(this); 644 } 645 646 // Used by scavengers 647 648 inline bool oopDesc::is_forwarded() const { 649 // The extra heap check is needed since the obj might be locked, in which case the 650 // mark would point to a stack location and have the sentinel bit cleared 651 return mark()->is_marked(); 652 } 653 654 // Used by scavengers 655 inline void oopDesc::forward_to(oop p) { 656 assert(check_obj_alignment(p), 657 "forwarding to something not aligned"); 658 assert(Universe::heap()->is_in_reserved(p), 659 "forwarding to something not in heap"); 660 markOop m = markOopDesc::encode_pointer_as_mark(p); 661 assert(m->decode_pointer() == p, "encoding must be reversable"); 662 set_mark(m); 663 } 664 665 // Used by parallel scavengers 666 inline bool oopDesc::cas_forward_to(oop p, markOop compare) { 667 assert(check_obj_alignment(p), 668 "forwarding to something not aligned"); 669 assert(Universe::heap()->is_in_reserved(p), 670 "forwarding to something not in heap"); 671 markOop m = markOopDesc::encode_pointer_as_mark(p); 672 assert(m->decode_pointer() == p, "encoding must be reversable"); 673 return cas_set_mark(m, compare) == compare; 674 } 675 676 // Note that the forwardee is not the same thing as the displaced_mark. 677 // The forwardee is used when copying during scavenge and mark-sweep. 678 // It does need to clear the low two locking- and GC-related bits. 679 inline oop oopDesc::forwardee() const { 680 return (oop) mark()->decode_pointer(); 681 } 682 683 inline bool oopDesc::has_displaced_mark() const { 684 return mark()->has_displaced_mark_helper(); 685 } 686 687 inline markOop oopDesc::displaced_mark() const { 688 return mark()->displaced_mark_helper(); 689 } 690 691 inline void oopDesc::set_displaced_mark(markOop m) { 692 mark()->set_displaced_mark_helper(m); 693 } 694 695 // The following method needs to be MT safe. 696 inline uint oopDesc::age() const { 697 assert(!is_forwarded(), "Attempt to read age from forwarded mark"); 698 if (has_displaced_mark()) { 699 return displaced_mark()->age(); 700 } else { 701 return mark()->age(); 702 } 703 } 704 705 inline void oopDesc::incr_age() { 706 assert(!is_forwarded(), "Attempt to increment age of forwarded mark"); 707 if (has_displaced_mark()) { 708 set_displaced_mark(displaced_mark()->incr_age()); 709 } else { 710 set_mark(mark()->incr_age()); 711 } 712 } 713 714 715 inline intptr_t oopDesc::identity_hash() { 716 // Fast case; if the object is unlocked and the hash value is set, no locking is needed 717 // Note: The mark must be read into local variable to avoid concurrent updates. 718 markOop mrk = mark(); 719 if (mrk->is_unlocked() && !mrk->has_no_hash()) { 720 return mrk->hash(); 721 } else if (mrk->is_marked()) { 722 return mrk->hash(); 723 } else { 724 return slow_identity_hash(); 725 } 726 } 727 728 inline int oopDesc::adjust_pointers() { 729 debug_only(int check_size = size()); 730 int s = klass()->oop_adjust_pointers(this); 731 assert(s == check_size, "should be the same"); 732 return s; 733 } 734 735 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \ 736 \ 737 inline int oopDesc::oop_iterate(OopClosureType* blk) { \ 738 SpecializationStats::record_call(); \ 739 return klass()->oop_oop_iterate##nv_suffix(this, blk); \ 740 } \ 741 \ 742 inline int oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \ 743 SpecializationStats::record_call(); \ 744 return klass()->oop_oop_iterate##nv_suffix##_m(this, blk, mr); \ 745 } 746 747 748 inline int oopDesc::oop_iterate_no_header(OopClosure* blk) { 749 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all 750 // the do_oop calls, but turns off all other features in ExtendedOopClosure. 751 NoHeaderExtendedOopClosure cl(blk); 752 return oop_iterate(&cl); 753 } 754 755 inline int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) { 756 NoHeaderExtendedOopClosure cl(blk); 757 return oop_iterate(&cl, mr); 758 } 759 760 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_DEFN) 761 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_DEFN) 762 763 #if INCLUDE_ALL_GCS 764 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \ 765 \ 766 inline int oopDesc::oop_iterate_backwards(OopClosureType* blk) { \ 767 SpecializationStats::record_call(); \ 768 return klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \ 769 } 770 771 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_ITERATE_BACKWARDS_DEFN) 772 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_ITERATE_BACKWARDS_DEFN) 773 #endif // INCLUDE_ALL_GCS 774 775 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP