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/shared/ageTable.hpp" 29 #include "gc/shared/barrierSet.inline.hpp" 30 #include "gc/shared/cardTableModRefBS.hpp" 31 #include "gc/shared/collectedHeap.inline.hpp" 32 #include "gc/shared/genCollectedHeap.hpp" 33 #include "gc/shared/generation.hpp" 34 #include "oops/arrayKlass.hpp" 35 #include "oops/arrayOop.hpp" 36 #include "oops/klass.inline.hpp" 37 #include "oops/markOop.inline.hpp" 38 #include "oops/oop.hpp" 39 #include "runtime/atomic.hpp" 40 #include "runtime/orderAccess.inline.hpp" 41 #include "runtime/os.hpp" 42 #include "utilities/macros.hpp" 43 44 inline void update_barrier_set(void* p, oop v, bool release = false) { 45 assert(oopDesc::bs() != NULL, "Uninitialized bs in oop!"); 46 oopDesc::bs()->write_ref_field(p, v, release); 47 } 48 49 template <class T> inline void update_barrier_set_pre(T* p, oop v) { 50 oopDesc::bs()->write_ref_field_pre(p, v); 51 } 52 53 template <class T> void oop_store(T* p, oop v) { 54 if (always_do_update_barrier) { 55 oop_store((volatile T*)p, v); 56 } else { 57 update_barrier_set_pre(p, v); 58 oopDesc::encode_store_heap_oop(p, v); 59 // always_do_update_barrier == false => 60 // Either we are at a safepoint (in GC) or CMS is not used. In both 61 // cases it's unnecessary to mark the card as dirty with release sematics. 62 update_barrier_set((void*)p, v, false /* release */); // cast away type 63 } 64 } 65 66 template <class T> void oop_store(volatile T* p, oop v) { 67 update_barrier_set_pre((T*)p, v); // cast away volatile 68 // Used by release_obj_field_put, so use release_store_ptr. 69 oopDesc::release_encode_store_heap_oop(p, v); 70 // When using CMS we must mark the card corresponding to p as dirty 71 // with release sematics to prevent that CMS sees the dirty card but 72 // not the new value v at p due to reordering of the two 73 // stores. Note that CMS has a concurrent precleaning phase, where 74 // it reads the card table while the Java threads are running. 75 update_barrier_set((void*)p, v, true /* release */); // cast away type 76 } 77 78 // Should replace *addr = oop assignments where addr type depends on UseCompressedOops 79 // (without having to remember the function name this calls). 80 inline void oop_store_raw(HeapWord* addr, oop value) { 81 if (UseCompressedOops) { 82 oopDesc::encode_store_heap_oop((narrowOop*)addr, value); 83 } else { 84 oopDesc::encode_store_heap_oop((oop*)addr, value); 85 } 86 } 87 88 // Implementation of all inlined member functions defined in oop.hpp 89 // We need a separate file to avoid circular references 90 91 void oopDesc::release_set_mark(markOop m) { 92 OrderAccess::release_store_ptr(&_mark, m); 93 } 94 95 markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) { 96 return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark); 97 } 98 99 void oopDesc::init_mark() { 100 set_mark(markOopDesc::prototype_for_object(this)); 101 } 102 103 Klass* oopDesc::klass() const { 104 if (UseCompressedClassPointers) { 105 return Klass::decode_klass_not_null(_metadata._compressed_klass); 106 } else { 107 return _metadata._klass; 108 } 109 } 110 111 Klass* oopDesc::klass_or_null() const volatile { 112 if (UseCompressedClassPointers) { 113 return Klass::decode_klass(_metadata._compressed_klass); 114 } else { 115 return _metadata._klass; 116 } 117 } 118 119 Klass* oopDesc::klass_or_null_acquire() const volatile { 120 if (UseCompressedClassPointers) { 121 // Workaround for non-const load_acquire parameter. 122 const volatile narrowKlass* addr = &_metadata._compressed_klass; 123 volatile narrowKlass* xaddr = const_cast<volatile narrowKlass*>(addr); 124 return Klass::decode_klass(OrderAccess::load_acquire(xaddr)); 125 } else { 126 return (Klass*)OrderAccess::load_ptr_acquire(&_metadata._klass); 127 } 128 } 129 130 Klass** oopDesc::klass_addr() { 131 // Only used internally and with CMS and will not work with 132 // UseCompressedOops 133 assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers"); 134 return (Klass**) &_metadata._klass; 135 } 136 137 narrowKlass* oopDesc::compressed_klass_addr() { 138 assert(UseCompressedClassPointers, "only called by compressed klass pointers"); 139 return &_metadata._compressed_klass; 140 } 141 142 #define CHECK_SET_KLASS(k) \ 143 do { \ 144 assert(Universe::is_bootstrapping() || k != NULL, "NULL Klass"); \ 145 assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass"); \ 146 } while (0) 147 148 void oopDesc::set_klass(Klass* k) { 149 CHECK_SET_KLASS(k); 150 if (UseCompressedClassPointers) { 151 *compressed_klass_addr() = Klass::encode_klass_not_null(k); 152 } else { 153 *klass_addr() = k; 154 } 155 } 156 157 void oopDesc::release_set_klass(Klass* k) { 158 CHECK_SET_KLASS(k); 159 if (UseCompressedClassPointers) { 160 OrderAccess::release_store(compressed_klass_addr(), 161 Klass::encode_klass_not_null(k)); 162 } else { 163 OrderAccess::release_store_ptr(klass_addr(), k); 164 } 165 } 166 167 #undef CHECK_SET_KLASS 168 169 int oopDesc::klass_gap() const { 170 return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()); 171 } 172 173 void oopDesc::set_klass_gap(int v) { 174 if (UseCompressedClassPointers) { 175 *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v; 176 } 177 } 178 179 void oopDesc::set_klass_to_list_ptr(oop k) { 180 // This is only to be used during GC, for from-space objects, so no 181 // barrier is needed. 182 if (UseCompressedClassPointers) { 183 _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k); // may be null (parnew overflow handling) 184 } else { 185 _metadata._klass = (Klass*)(address)k; 186 } 187 } 188 189 oop oopDesc::list_ptr_from_klass() { 190 // This is only to be used during GC, for from-space objects. 191 if (UseCompressedClassPointers) { 192 return decode_heap_oop((narrowOop)_metadata._compressed_klass); 193 } else { 194 // Special case for GC 195 return (oop)(address)_metadata._klass; 196 } 197 } 198 199 bool oopDesc::is_a(Klass* k) const { 200 return klass()->is_subtype_of(k); 201 } 202 203 int oopDesc::size() { 204 return size_given_klass(klass()); 205 } 206 207 int oopDesc::size_given_klass(Klass* klass) { 208 int lh = klass->layout_helper(); 209 int s; 210 211 // lh is now a value computed at class initialization that may hint 212 // at the size. For instances, this is positive and equal to the 213 // size. For arrays, this is negative and provides log2 of the 214 // array element size. For other oops, it is zero and thus requires 215 // a virtual call. 216 // 217 // We go to all this trouble because the size computation is at the 218 // heart of phase 2 of mark-compaction, and called for every object, 219 // alive or dead. So the speed here is equal in importance to the 220 // speed of allocation. 221 222 if (lh > Klass::_lh_neutral_value) { 223 if (!Klass::layout_helper_needs_slow_path(lh)) { 224 s = lh >> LogHeapWordSize; // deliver size scaled by wordSize 225 } else { 226 s = klass->oop_size(this); 227 } 228 } else if (lh <= Klass::_lh_neutral_value) { 229 // The most common case is instances; fall through if so. 230 if (lh < Klass::_lh_neutral_value) { 231 // Second most common case is arrays. We have to fetch the 232 // length of the array, shift (multiply) it appropriately, 233 // up to wordSize, add the header, and align to object size. 234 size_t size_in_bytes; 235 #ifdef _M_IA64 236 // The Windows Itanium Aug 2002 SDK hoists this load above 237 // the check for s < 0. An oop at the end of the heap will 238 // cause an access violation if this load is performed on a non 239 // array oop. Making the reference volatile prohibits this. 240 // (%%% please explain by what magic the length is actually fetched!) 241 volatile int *array_length; 242 array_length = (volatile int *)( (intptr_t)this + 243 arrayOopDesc::length_offset_in_bytes() ); 244 assert(array_length > 0, "Integer arithmetic problem somewhere"); 245 // Put into size_t to avoid overflow. 246 size_in_bytes = (size_t) array_length; 247 size_in_bytes = size_in_bytes << Klass::layout_helper_log2_element_size(lh); 248 #else 249 size_t array_length = (size_t) ((arrayOop)this)->length(); 250 size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh); 251 #endif 252 size_in_bytes += Klass::layout_helper_header_size(lh); 253 254 // This code could be simplified, but by keeping array_header_in_bytes 255 // in units of bytes and doing it this way we can round up just once, 256 // skipping the intermediate round to HeapWordSize. Cast the result 257 // of round_to to size_t to guarantee unsigned division == right shift. 258 s = (int)((size_t)round_to(size_in_bytes, MinObjAlignmentInBytes) / 259 HeapWordSize); 260 261 // ParNew (used by CMS), UseParallelGC and UseG1GC can change the length field 262 // of an "old copy" of an object array in the young gen so it indicates 263 // the grey portion of an already copied array. This will cause the first 264 // disjunct below to fail if the two comparands are computed across such 265 // a concurrent change. 266 // ParNew also runs with promotion labs (which look like int 267 // filler arrays) which are subject to changing their declared size 268 // when finally retiring a PLAB; this also can cause the first disjunct 269 // to fail for another worker thread that is concurrently walking the block 270 // offset table. Both these invariant failures are benign for their 271 // current uses; we relax the assertion checking to cover these two cases below: 272 // is_objArray() && is_forwarded() // covers first scenario above 273 // || is_typeArray() // covers second scenario above 274 // If and when UseParallelGC uses the same obj array oop stealing/chunking 275 // technique, we will need to suitably modify the assertion. 276 assert((s == klass->oop_size(this)) || 277 (Universe::heap()->is_gc_active() && 278 ((is_typeArray() && UseConcMarkSweepGC) || 279 (is_objArray() && is_forwarded() && (UseConcMarkSweepGC || UseParallelGC || UseG1GC)))), 280 "wrong array object size"); 281 } else { 282 // Must be zero, so bite the bullet and take the virtual call. 283 s = klass->oop_size(this); 284 } 285 } 286 287 assert(s % MinObjAlignment == 0, "Oop size is not properly aligned: %d", s); 288 assert(s > 0, "Oop size must be greater than zero, not %d", s); 289 return s; 290 } 291 292 bool oopDesc::is_instance() const { return klass()->is_instance_klass(); } 293 bool oopDesc::is_array() const { return klass()->is_array_klass(); } 294 bool oopDesc::is_objArray() const { return klass()->is_objArray_klass(); } 295 bool oopDesc::is_typeArray() const { return klass()->is_typeArray_klass(); } 296 297 void* oopDesc::field_base(int offset) const { return (void*)&((char*)this)[offset]; } 298 299 jbyte* oopDesc::byte_field_addr(int offset) const { return (jbyte*) field_base(offset); } 300 jchar* oopDesc::char_field_addr(int offset) const { return (jchar*) field_base(offset); } 301 jboolean* oopDesc::bool_field_addr(int offset) const { return (jboolean*) field_base(offset); } 302 jint* oopDesc::int_field_addr(int offset) const { return (jint*) field_base(offset); } 303 jshort* oopDesc::short_field_addr(int offset) const { return (jshort*) field_base(offset); } 304 jlong* oopDesc::long_field_addr(int offset) const { return (jlong*) field_base(offset); } 305 jfloat* oopDesc::float_field_addr(int offset) const { return (jfloat*) field_base(offset); } 306 jdouble* oopDesc::double_field_addr(int offset) const { return (jdouble*) field_base(offset); } 307 Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); } 308 309 template <class T> T* oopDesc::obj_field_addr(int offset) const { return (T*) field_base(offset); } 310 address* oopDesc::address_field_addr(int offset) const { return (address*) field_base(offset); } 311 312 313 // Functions for getting and setting oops within instance objects. 314 // If the oops are compressed, the type passed to these overloaded functions 315 // is narrowOop. All functions are overloaded so they can be called by 316 // template functions without conditionals (the compiler instantiates via 317 // the right type and inlines the appopriate code). 318 319 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit 320 // offset from the heap base. Saving the check for null can save instructions 321 // in inner GC loops so these are separated. 322 323 inline bool check_obj_alignment(oop obj) { 324 return (cast_from_oop<intptr_t>(obj) & MinObjAlignmentInBytesMask) == 0; 325 } 326 327 oop oopDesc::decode_heap_oop_not_null(narrowOop v) { 328 assert(!is_null(v), "narrow oop value can never be zero"); 329 address base = Universe::narrow_oop_base(); 330 int shift = Universe::narrow_oop_shift(); 331 oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift)); 332 assert(check_obj_alignment(result), "address not aligned: " INTPTR_FORMAT, p2i((void*) result)); 333 return result; 334 } 335 336 oop oopDesc::decode_heap_oop(narrowOop v) { 337 return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v); 338 } 339 340 narrowOop oopDesc::encode_heap_oop_not_null(oop v) { 341 assert(!is_null(v), "oop value can never be zero"); 342 assert(check_obj_alignment(v), "Address not aligned"); 343 assert(Universe::heap()->is_in_reserved(v), "Address not in heap"); 344 address base = Universe::narrow_oop_base(); 345 int shift = Universe::narrow_oop_shift(); 346 uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1)); 347 assert(OopEncodingHeapMax > pd, "change encoding max if new encoding"); 348 uint64_t result = pd >> shift; 349 assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow"); 350 assert(decode_heap_oop(result) == v, "reversibility"); 351 return (narrowOop)result; 352 } 353 354 narrowOop oopDesc::encode_heap_oop(oop v) { 355 return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v); 356 } 357 358 // Load and decode an oop out of the Java heap into a wide oop. 359 oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) { 360 return decode_heap_oop_not_null(*p); 361 } 362 363 // Load and decode an oop out of the heap accepting null 364 oop oopDesc::load_decode_heap_oop(narrowOop* p) { 365 return decode_heap_oop(*p); 366 } 367 368 // Encode and store a heap oop. 369 void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) { 370 *p = encode_heap_oop_not_null(v); 371 } 372 373 // Encode and store a heap oop allowing for null. 374 void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) { 375 *p = encode_heap_oop(v); 376 } 377 378 // Store heap oop as is for volatile fields. 379 void oopDesc::release_store_heap_oop(volatile oop* p, oop v) { 380 OrderAccess::release_store_ptr(p, v); 381 } 382 void oopDesc::release_store_heap_oop(volatile narrowOop* p, narrowOop v) { 383 OrderAccess::release_store(p, v); 384 } 385 386 void oopDesc::release_encode_store_heap_oop_not_null(volatile narrowOop* p, oop v) { 387 // heap oop is not pointer sized. 388 OrderAccess::release_store(p, encode_heap_oop_not_null(v)); 389 } 390 void oopDesc::release_encode_store_heap_oop_not_null(volatile oop* p, oop v) { 391 OrderAccess::release_store_ptr(p, v); 392 } 393 394 void oopDesc::release_encode_store_heap_oop(volatile oop* p, oop v) { 395 OrderAccess::release_store_ptr(p, v); 396 } 397 void oopDesc::release_encode_store_heap_oop(volatile narrowOop* p, oop v) { 398 OrderAccess::release_store(p, encode_heap_oop(v)); 399 } 400 401 // These functions are only used to exchange oop fields in instances, 402 // not headers. 403 oop oopDesc::atomic_exchange_oop(oop exchange_value, volatile HeapWord *dest) { 404 if (UseCompressedOops) { 405 // encode exchange value from oop to T 406 narrowOop val = encode_heap_oop(exchange_value); 407 narrowOop old = (narrowOop)Atomic::xchg(val, (narrowOop*)dest); 408 // decode old from T to oop 409 return decode_heap_oop(old); 410 } else { 411 return (oop)Atomic::xchg_ptr(exchange_value, (oop*)dest); 412 } 413 } 414 415 oop oopDesc::atomic_compare_exchange_oop(oop exchange_value, 416 volatile HeapWord *dest, 417 oop compare_value, 418 bool prebarrier) { 419 if (UseCompressedOops) { 420 if (prebarrier) { 421 update_barrier_set_pre((narrowOop*)dest, exchange_value); 422 } 423 // encode exchange and compare value from oop to T 424 narrowOop val = encode_heap_oop(exchange_value); 425 narrowOop cmp = encode_heap_oop(compare_value); 426 427 narrowOop old = (narrowOop) Atomic::cmpxchg(val, (narrowOop*)dest, cmp); 428 // decode old from T to oop 429 return decode_heap_oop(old); 430 } else { 431 if (prebarrier) { 432 update_barrier_set_pre((oop*)dest, exchange_value); 433 } 434 return (oop)Atomic::cmpxchg_ptr(exchange_value, (oop*)dest, compare_value); 435 } 436 } 437 438 // In order to put or get a field out of an instance, must first check 439 // if the field has been compressed and uncompress it. 440 oop oopDesc::obj_field(int offset) const { 441 return UseCompressedOops ? 442 load_decode_heap_oop(obj_field_addr<narrowOop>(offset)) : 443 load_decode_heap_oop(obj_field_addr<oop>(offset)); 444 } 445 446 void oopDesc::obj_field_put(int offset, oop value) { 447 UseCompressedOops ? oop_store(obj_field_addr<narrowOop>(offset), value) : 448 oop_store(obj_field_addr<oop>(offset), value); 449 } 450 451 void oopDesc::obj_field_put_raw(int offset, oop value) { 452 UseCompressedOops ? 453 encode_store_heap_oop(obj_field_addr<narrowOop>(offset), value) : 454 encode_store_heap_oop(obj_field_addr<oop>(offset), value); 455 } 456 void oopDesc::obj_field_put_volatile(int offset, oop value) { 457 OrderAccess::release(); 458 obj_field_put(offset, value); 459 OrderAccess::fence(); 460 } 461 462 Metadata* oopDesc::metadata_field(int offset) const { return *metadata_field_addr(offset); } 463 void oopDesc::metadata_field_put(int offset, Metadata* value) { *metadata_field_addr(offset) = value; } 464 465 jbyte oopDesc::byte_field(int offset) const { return (jbyte) *byte_field_addr(offset); } 466 void oopDesc::byte_field_put(int offset, jbyte contents) { *byte_field_addr(offset) = (jint) contents; } 467 468 jchar oopDesc::char_field(int offset) const { return (jchar) *char_field_addr(offset); } 469 void oopDesc::char_field_put(int offset, jchar contents) { *char_field_addr(offset) = (jint) contents; } 470 471 jboolean oopDesc::bool_field(int offset) const { return (jboolean) *bool_field_addr(offset); } 472 void oopDesc::bool_field_put(int offset, jboolean contents) { *bool_field_addr(offset) = (((jint) contents) & 1); } 473 474 jint oopDesc::int_field(int offset) const { return *int_field_addr(offset); } 475 void oopDesc::int_field_put(int offset, jint contents) { *int_field_addr(offset) = contents; } 476 477 jshort oopDesc::short_field(int offset) const { return (jshort) *short_field_addr(offset); } 478 void oopDesc::short_field_put(int offset, jshort contents) { *short_field_addr(offset) = (jint) contents;} 479 480 jlong oopDesc::long_field(int offset) const { return *long_field_addr(offset); } 481 void oopDesc::long_field_put(int offset, jlong contents) { *long_field_addr(offset) = contents; } 482 483 jfloat oopDesc::float_field(int offset) const { return *float_field_addr(offset); } 484 void oopDesc::float_field_put(int offset, jfloat contents) { *float_field_addr(offset) = contents; } 485 486 jdouble oopDesc::double_field(int offset) const { return *double_field_addr(offset); } 487 void oopDesc::double_field_put(int offset, jdouble contents) { *double_field_addr(offset) = contents; } 488 489 address oopDesc::address_field(int offset) const { return *address_field_addr(offset); } 490 void oopDesc::address_field_put(int offset, address contents) { *address_field_addr(offset) = contents; } 491 492 oop oopDesc::obj_field_acquire(int offset) const { 493 return UseCompressedOops ? 494 decode_heap_oop((narrowOop) 495 OrderAccess::load_acquire(obj_field_addr<narrowOop>(offset))) 496 : decode_heap_oop((oop) 497 OrderAccess::load_ptr_acquire(obj_field_addr<oop>(offset))); 498 } 499 void oopDesc::release_obj_field_put(int offset, oop value) { 500 UseCompressedOops ? 501 oop_store((volatile narrowOop*)obj_field_addr<narrowOop>(offset), value) : 502 oop_store((volatile oop*) obj_field_addr<oop>(offset), value); 503 } 504 505 jbyte oopDesc::byte_field_acquire(int offset) const { return OrderAccess::load_acquire(byte_field_addr(offset)); } 506 void oopDesc::release_byte_field_put(int offset, jbyte contents) { OrderAccess::release_store(byte_field_addr(offset), contents); } 507 508 jchar oopDesc::char_field_acquire(int offset) const { return OrderAccess::load_acquire(char_field_addr(offset)); } 509 void oopDesc::release_char_field_put(int offset, jchar contents) { OrderAccess::release_store(char_field_addr(offset), contents); } 510 511 jboolean oopDesc::bool_field_acquire(int offset) const { return OrderAccess::load_acquire(bool_field_addr(offset)); } 512 void oopDesc::release_bool_field_put(int offset, jboolean contents) { OrderAccess::release_store(bool_field_addr(offset), (contents & 1)); } 513 514 jint oopDesc::int_field_acquire(int offset) const { return OrderAccess::load_acquire(int_field_addr(offset)); } 515 void oopDesc::release_int_field_put(int offset, jint contents) { OrderAccess::release_store(int_field_addr(offset), contents); } 516 517 jshort oopDesc::short_field_acquire(int offset) const { return (jshort)OrderAccess::load_acquire(short_field_addr(offset)); } 518 void oopDesc::release_short_field_put(int offset, jshort contents) { OrderAccess::release_store(short_field_addr(offset), contents); } 519 520 jlong oopDesc::long_field_acquire(int offset) const { return OrderAccess::load_acquire(long_field_addr(offset)); } 521 void oopDesc::release_long_field_put(int offset, jlong contents) { OrderAccess::release_store(long_field_addr(offset), contents); } 522 523 jfloat oopDesc::float_field_acquire(int offset) const { return OrderAccess::load_acquire(float_field_addr(offset)); } 524 void oopDesc::release_float_field_put(int offset, jfloat contents) { OrderAccess::release_store(float_field_addr(offset), contents); } 525 526 jdouble oopDesc::double_field_acquire(int offset) const { return OrderAccess::load_acquire(double_field_addr(offset)); } 527 void oopDesc::release_double_field_put(int offset, jdouble contents) { OrderAccess::release_store(double_field_addr(offset), contents); } 528 529 address oopDesc::address_field_acquire(int offset) const { return (address) OrderAccess::load_ptr_acquire(address_field_addr(offset)); } 530 void oopDesc::release_address_field_put(int offset, address contents) { OrderAccess::release_store_ptr(address_field_addr(offset), contents); } 531 532 bool oopDesc::is_locked() const { 533 return mark()->is_locked(); 534 } 535 536 bool oopDesc::is_unlocked() const { 537 return mark()->is_unlocked(); 538 } 539 540 bool oopDesc::has_bias_pattern() const { 541 return mark()->has_bias_pattern(); 542 } 543 544 // used only for asserts 545 bool oopDesc::is_oop(bool ignore_mark_word) const { 546 oop obj = (oop) this; 547 if (!check_obj_alignment(obj)) return false; 548 if (!Universe::heap()->is_in_reserved(obj)) return false; 549 // obj is aligned and accessible in heap 550 if (Universe::heap()->is_in_reserved(obj->klass_or_null())) return false; 551 552 // Header verification: the mark is typically non-NULL. If we're 553 // at a safepoint, it must not be null. 554 // Outside of a safepoint, the header could be changing (for example, 555 // another thread could be inflating a lock on this object). 556 if (ignore_mark_word) { 557 return true; 558 } 559 if (mark() != NULL) { 560 return true; 561 } 562 return !SafepointSynchronize::is_at_safepoint(); 563 } 564 565 566 // used only for asserts 567 bool oopDesc::is_oop_or_null(bool ignore_mark_word) const { 568 return this == NULL ? true : is_oop(ignore_mark_word); 569 } 570 571 #ifndef PRODUCT 572 // used only for asserts 573 bool oopDesc::is_unlocked_oop() const { 574 if (!Universe::heap()->is_in_reserved(this)) return false; 575 return mark()->is_unlocked(); 576 } 577 #endif // PRODUCT 578 579 // Used only for markSweep, scavenging 580 bool oopDesc::is_gc_marked() const { 581 return mark()->is_marked(); 582 } 583 584 bool oopDesc::is_scavengable() const { 585 return Universe::heap()->is_scavengable(this); 586 } 587 588 // Used by scavengers 589 bool oopDesc::is_forwarded() const { 590 // The extra heap check is needed since the obj might be locked, in which case the 591 // mark would point to a stack location and have the sentinel bit cleared 592 return mark()->is_marked(); 593 } 594 595 // Used by scavengers 596 void oopDesc::forward_to(oop p) { 597 assert(check_obj_alignment(p), 598 "forwarding to something not aligned"); 599 assert(Universe::heap()->is_in_reserved(p), 600 "forwarding to something not in heap"); 601 markOop m = markOopDesc::encode_pointer_as_mark(p); 602 assert(m->decode_pointer() == p, "encoding must be reversable"); 603 set_mark(m); 604 } 605 606 // Used by parallel scavengers 607 bool oopDesc::cas_forward_to(oop p, markOop compare) { 608 assert(check_obj_alignment(p), 609 "forwarding to something not aligned"); 610 assert(Universe::heap()->is_in_reserved(p), 611 "forwarding to something not in heap"); 612 markOop m = markOopDesc::encode_pointer_as_mark(p); 613 assert(m->decode_pointer() == p, "encoding must be reversable"); 614 return cas_set_mark(m, compare) == compare; 615 } 616 617 #if INCLUDE_ALL_GCS 618 oop oopDesc::forward_to_atomic(oop p) { 619 markOop oldMark = mark(); 620 markOop forwardPtrMark = markOopDesc::encode_pointer_as_mark(p); 621 markOop curMark; 622 623 assert(forwardPtrMark->decode_pointer() == p, "encoding must be reversable"); 624 assert(sizeof(markOop) == sizeof(intptr_t), "CAS below requires this."); 625 626 while (!oldMark->is_marked()) { 627 curMark = (markOop)Atomic::cmpxchg_ptr(forwardPtrMark, &_mark, oldMark); 628 assert(is_forwarded(), "object should have been forwarded"); 629 if (curMark == oldMark) { 630 return NULL; 631 } 632 // If the CAS was unsuccessful then curMark->is_marked() 633 // should return true as another thread has CAS'd in another 634 // forwarding pointer. 635 oldMark = curMark; 636 } 637 return forwardee(); 638 } 639 #endif 640 641 // Note that the forwardee is not the same thing as the displaced_mark. 642 // The forwardee is used when copying during scavenge and mark-sweep. 643 // It does need to clear the low two locking- and GC-related bits. 644 oop oopDesc::forwardee() const { 645 return (oop) mark()->decode_pointer(); 646 } 647 648 // The following method needs to be MT safe. 649 uint oopDesc::age() const { 650 assert(!is_forwarded(), "Attempt to read age from forwarded mark"); 651 if (has_displaced_mark()) { 652 return displaced_mark()->age(); 653 } else { 654 return mark()->age(); 655 } 656 } 657 658 void oopDesc::incr_age() { 659 assert(!is_forwarded(), "Attempt to increment age of forwarded mark"); 660 if (has_displaced_mark()) { 661 set_displaced_mark(displaced_mark()->incr_age()); 662 } else { 663 set_mark(mark()->incr_age()); 664 } 665 } 666 667 int oopDesc::ms_adjust_pointers() { 668 debug_only(int check_size = size()); 669 int s = klass()->oop_ms_adjust_pointers(this); 670 assert(s == check_size, "should be the same"); 671 return s; 672 } 673 674 #if INCLUDE_ALL_GCS 675 void oopDesc::pc_follow_contents(ParCompactionManager* cm) { 676 klass()->oop_pc_follow_contents(this, cm); 677 } 678 679 void oopDesc::pc_update_contents(ParCompactionManager* cm) { 680 Klass* k = klass(); 681 if (!k->is_typeArray_klass()) { 682 // It might contain oops beyond the header, so take the virtual call. 683 k->oop_pc_update_pointers(this, cm); 684 } 685 // Else skip it. The TypeArrayKlass in the header never needs scavenging. 686 } 687 688 void oopDesc::ps_push_contents(PSPromotionManager* pm) { 689 Klass* k = klass(); 690 if (!k->is_typeArray_klass()) { 691 // It might contain oops beyond the header, so take the virtual call. 692 k->oop_ps_push_contents(this, pm); 693 } 694 // Else skip it. The TypeArrayKlass in the header never needs scavenging. 695 } 696 #endif // INCLUDE_ALL_GCS 697 698 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \ 699 \ 700 void oopDesc::oop_iterate(OopClosureType* blk) { \ 701 klass()->oop_oop_iterate##nv_suffix(this, blk); \ 702 } \ 703 \ 704 void oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) { \ 705 klass()->oop_oop_iterate_bounded##nv_suffix(this, blk, mr); \ 706 } 707 708 #define OOP_ITERATE_SIZE_DEFN(OopClosureType, nv_suffix) \ 709 \ 710 int oopDesc::oop_iterate_size(OopClosureType* blk) { \ 711 Klass* k = klass(); \ 712 int size = size_given_klass(k); \ 713 k->oop_oop_iterate##nv_suffix(this, blk); \ 714 return size; \ 715 } \ 716 \ 717 int oopDesc::oop_iterate_size(OopClosureType* blk, MemRegion mr) { \ 718 Klass* k = klass(); \ 719 int size = size_given_klass(k); \ 720 k->oop_oop_iterate_bounded##nv_suffix(this, blk, mr); \ 721 return size; \ 722 } 723 724 int oopDesc::oop_iterate_no_header(OopClosure* blk) { 725 // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all 726 // the do_oop calls, but turns off all other features in ExtendedOopClosure. 727 NoHeaderExtendedOopClosure cl(blk); 728 return oop_iterate_size(&cl); 729 } 730 731 int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) { 732 NoHeaderExtendedOopClosure cl(blk); 733 return oop_iterate_size(&cl, mr); 734 } 735 736 #if INCLUDE_ALL_GCS 737 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \ 738 \ 739 inline void oopDesc::oop_iterate_backwards(OopClosureType* blk) { \ 740 klass()->oop_oop_iterate_backwards##nv_suffix(this, blk); \ 741 } 742 #else 743 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) 744 #endif // INCLUDE_ALL_GCS 745 746 #define ALL_OOPDESC_OOP_ITERATE(OopClosureType, nv_suffix) \ 747 OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \ 748 OOP_ITERATE_SIZE_DEFN(OopClosureType, nv_suffix) \ 749 OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) 750 751 ALL_OOP_OOP_ITERATE_CLOSURES_1(ALL_OOPDESC_OOP_ITERATE) 752 ALL_OOP_OOP_ITERATE_CLOSURES_2(ALL_OOPDESC_OOP_ITERATE) 753 754 intptr_t oopDesc::identity_hash() { 755 // Fast case; if the object is unlocked and the hash value is set, no locking is needed 756 // Note: The mark must be read into local variable to avoid concurrent updates. 757 markOop mrk = mark(); 758 if (mrk->is_unlocked() && !mrk->has_no_hash()) { 759 return mrk->hash(); 760 } else if (mrk->is_marked()) { 761 return mrk->hash(); 762 } else { 763 return slow_identity_hash(); 764 } 765 } 766 767 bool oopDesc::has_displaced_mark() const { 768 return mark()->has_displaced_mark_helper(); 769 } 770 771 markOop oopDesc::displaced_mark() const { 772 return mark()->displaced_mark_helper(); 773 } 774 775 void oopDesc::set_displaced_mark(markOop m) { 776 mark()->set_displaced_mark_helper(m); 777 } 778 779 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP