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 #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/collectedHeap.inline.hpp"
  30 #include "gc/shared/genCollectedHeap.hpp"
  31 #include "gc/shared/generation.hpp"
  32 #include "oops/access.inline.hpp"
  33 #include "oops/arrayKlass.hpp"
  34 #include "oops/arrayOop.hpp"
  35 #include "oops/klass.inline.hpp"
  36 #include "oops/markOop.inline.hpp"
  37 #include "oops/oop.hpp"
  38 #include "runtime/atomic.hpp"
  39 #include "runtime/orderAccess.inline.hpp"
  40 #include "runtime/os.hpp"
  41 #include "utilities/align.hpp"
  42 #include "utilities/macros.hpp"
  43 
  44 // Implementation of all inlined member functions defined in oop.hpp
  45 // We need a separate file to avoid circular references
  46 
  47 void oopDesc::release_set_mark(markOop m) {
  48   OrderAccess::release_store(&_mark, m);
  49 }
  50 
  51 markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) {
  52   return Atomic::cmpxchg(new_mark, &_mark, old_mark);
  53 }
  54 
  55 void oopDesc::init_mark() {
  56   set_mark(markOopDesc::prototype_for_object(this));
  57 }
  58 
  59 Klass* oopDesc::klass() const {
  60   if (UseCompressedClassPointers) {
  61     return Klass::decode_klass_not_null(_metadata._compressed_klass);
  62   } else {
  63     return _metadata._klass;
  64   }
  65 }
  66 
  67 Klass* oopDesc::klass_or_null() const volatile {
  68   if (UseCompressedClassPointers) {
  69     return Klass::decode_klass(_metadata._compressed_klass);
  70   } else {
  71     return _metadata._klass;
  72   }
  73 }
  74 
  75 Klass* oopDesc::klass_or_null_acquire() const volatile {
  76   if (UseCompressedClassPointers) {
  77     // Workaround for non-const load_acquire parameter.
  78     const volatile narrowKlass* addr = &_metadata._compressed_klass;
  79     volatile narrowKlass* xaddr = const_cast<volatile narrowKlass*>(addr);
  80     return Klass::decode_klass(OrderAccess::load_acquire(xaddr));
  81   } else {
  82     return OrderAccess::load_acquire(&_metadata._klass);
  83   }
  84 }
  85 
  86 Klass** oopDesc::klass_addr() {
  87   // Only used internally and with CMS and will not work with
  88   // UseCompressedOops
  89   assert(!UseCompressedClassPointers, "only supported with uncompressed klass pointers");
  90   return (Klass**) &_metadata._klass;
  91 }
  92 
  93 narrowKlass* oopDesc::compressed_klass_addr() {
  94   assert(UseCompressedClassPointers, "only called by compressed klass pointers");
  95   return &_metadata._compressed_klass;
  96 }
  97 
  98 #define CHECK_SET_KLASS(k)                                                \
  99   do {                                                                    \
 100     assert(Universe::is_bootstrapping() || k != NULL, "NULL Klass");      \
 101     assert(Universe::is_bootstrapping() || k->is_klass(), "not a Klass"); \
 102   } while (0)
 103 
 104 void oopDesc::set_klass(Klass* k) {
 105   CHECK_SET_KLASS(k);
 106   if (UseCompressedClassPointers) {
 107     *compressed_klass_addr() = Klass::encode_klass_not_null(k);
 108   } else {
 109     *klass_addr() = k;
 110   }
 111 }
 112 
 113 void oopDesc::release_set_klass(Klass* k) {
 114   CHECK_SET_KLASS(k);
 115   if (UseCompressedClassPointers) {
 116     OrderAccess::release_store(compressed_klass_addr(),
 117                                Klass::encode_klass_not_null(k));
 118   } else {
 119     OrderAccess::release_store(klass_addr(), k);
 120   }
 121 }
 122 
 123 #undef CHECK_SET_KLASS
 124 
 125 int oopDesc::klass_gap() const {
 126   return *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes());
 127 }
 128 
 129 void oopDesc::set_klass_gap(int v) {
 130   if (UseCompressedClassPointers) {
 131     *(int*)(((intptr_t)this) + klass_gap_offset_in_bytes()) = v;
 132   }
 133 }
 134 
 135 void oopDesc::set_klass_to_list_ptr(oop k) {
 136   // This is only to be used during GC, for from-space objects, so no
 137   // barrier is needed.
 138   if (UseCompressedClassPointers) {
 139     _metadata._compressed_klass = (narrowKlass)encode_heap_oop(k);  // may be null (parnew overflow handling)
 140   } else {
 141     _metadata._klass = (Klass*)(address)k;
 142   }
 143 }
 144 
 145 oop oopDesc::list_ptr_from_klass() {
 146   // This is only to be used during GC, for from-space objects.
 147   if (UseCompressedClassPointers) {
 148     return decode_heap_oop((narrowOop)_metadata._compressed_klass);
 149   } else {
 150     // Special case for GC
 151     return (oop)(address)_metadata._klass;
 152   }
 153 }
 154 
 155 bool oopDesc::is_a(Klass* k) const {
 156   return klass()->is_subtype_of(k);
 157 }
 158 
 159 int oopDesc::size()  {
 160   return size_given_klass(klass());
 161 }
 162 
 163 int oopDesc::size_given_klass(Klass* klass)  {
 164   int lh = klass->layout_helper();
 165   int s;
 166 
 167   // lh is now a value computed at class initialization that may hint
 168   // at the size.  For instances, this is positive and equal to the
 169   // size.  For arrays, this is negative and provides log2 of the
 170   // array element size.  For other oops, it is zero and thus requires
 171   // a virtual call.
 172   //
 173   // We go to all this trouble because the size computation is at the
 174   // heart of phase 2 of mark-compaction, and called for every object,
 175   // alive or dead.  So the speed here is equal in importance to the
 176   // speed of allocation.
 177 
 178   if (lh > Klass::_lh_neutral_value) {
 179     if (!Klass::layout_helper_needs_slow_path(lh)) {
 180       s = lh >> LogHeapWordSize;  // deliver size scaled by wordSize
 181     } else {
 182       s = klass->oop_size(this);
 183     }
 184   } else if (lh <= Klass::_lh_neutral_value) {
 185     // The most common case is instances; fall through if so.
 186     if (lh < Klass::_lh_neutral_value) {
 187       // Second most common case is arrays.  We have to fetch the
 188       // length of the array, shift (multiply) it appropriately,
 189       // up to wordSize, add the header, and align to object size.
 190       size_t size_in_bytes;
 191       size_t array_length = (size_t) ((arrayOop)this)->length();
 192       size_in_bytes = array_length << Klass::layout_helper_log2_element_size(lh);
 193       size_in_bytes += Klass::layout_helper_header_size(lh);
 194 
 195       // This code could be simplified, but by keeping array_header_in_bytes
 196       // in units of bytes and doing it this way we can round up just once,
 197       // skipping the intermediate round to HeapWordSize.
 198       s = (int)(align_up(size_in_bytes, MinObjAlignmentInBytes) / HeapWordSize);
 199 
 200       // ParNew (used by CMS), UseParallelGC and UseG1GC can change the length field
 201       // of an "old copy" of an object array in the young gen so it indicates
 202       // the grey portion of an already copied array. This will cause the first
 203       // disjunct below to fail if the two comparands are computed across such
 204       // a concurrent change.
 205       // ParNew also runs with promotion labs (which look like int
 206       // filler arrays) which are subject to changing their declared size
 207       // when finally retiring a PLAB; this also can cause the first disjunct
 208       // to fail for another worker thread that is concurrently walking the block
 209       // offset table. Both these invariant failures are benign for their
 210       // current uses; we relax the assertion checking to cover these two cases below:
 211       //     is_objArray() && is_forwarded()   // covers first scenario above
 212       //  || is_typeArray()                    // covers second scenario above
 213       // If and when UseParallelGC uses the same obj array oop stealing/chunking
 214       // technique, we will need to suitably modify the assertion.
 215       assert((s == klass->oop_size(this)) ||
 216              (Universe::heap()->is_gc_active() &&
 217               ((is_typeArray() && UseConcMarkSweepGC) ||
 218                (is_objArray()  && is_forwarded() && (UseConcMarkSweepGC || UseParallelGC || UseG1GC)))),
 219              "wrong array object size");
 220     } else {
 221       // Must be zero, so bite the bullet and take the virtual call.
 222       s = klass->oop_size(this);
 223     }
 224   }
 225 
 226   assert(s > 0, "Oop size must be greater than zero, not %d", s);
 227   assert(is_object_aligned(s), "Oop size is not properly aligned: %d", s);
 228   return s;
 229 }
 230 
 231 bool oopDesc::is_instance()  const { return klass()->is_instance_klass();  }
 232 bool oopDesc::is_array()     const { return klass()->is_array_klass();     }
 233 bool oopDesc::is_objArray()  const { return klass()->is_objArray_klass();  }
 234 bool oopDesc::is_typeArray() const { return klass()->is_typeArray_klass(); }
 235 
 236 void*      oopDesc::field_base(int offset)          const { return (void*)&((char*)this)[offset]; }
 237 
 238 jbyte*     oopDesc::byte_field_addr(int offset)     const { return (jbyte*)    field_base(offset); }
 239 jchar*     oopDesc::char_field_addr(int offset)     const { return (jchar*)    field_base(offset); }
 240 jboolean*  oopDesc::bool_field_addr(int offset)     const { return (jboolean*) field_base(offset); }
 241 jint*      oopDesc::int_field_addr(int offset)      const { return (jint*)     field_base(offset); }
 242 jshort*    oopDesc::short_field_addr(int offset)    const { return (jshort*)   field_base(offset); }
 243 jlong*     oopDesc::long_field_addr(int offset)     const { return (jlong*)    field_base(offset); }
 244 jfloat*    oopDesc::float_field_addr(int offset)    const { return (jfloat*)   field_base(offset); }
 245 jdouble*   oopDesc::double_field_addr(int offset)   const { return (jdouble*)  field_base(offset); }
 246 Metadata** oopDesc::metadata_field_addr(int offset) const { return (Metadata**)field_base(offset); }
 247 
 248 template <class T> T* oopDesc::obj_field_addr(int offset) const { return (T*)  field_base(offset); }
 249 address*   oopDesc::address_field_addr(int offset)  const { return (address*)  field_base(offset); }
 250 
 251 
 252 // Functions for getting and setting oops within instance objects.
 253 // If the oops are compressed, the type passed to these overloaded functions
 254 // is narrowOop.  All functions are overloaded so they can be called by
 255 // template functions without conditionals (the compiler instantiates via
 256 // the right type and inlines the appopriate code).
 257 
 258 // Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
 259 // offset from the heap base.  Saving the check for null can save instructions
 260 // in inner GC loops so these are separated.
 261 
 262 inline bool check_obj_alignment(oop obj) {
 263   return (cast_from_oop<intptr_t>(obj) & MinObjAlignmentInBytesMask) == 0;
 264 }
 265 
 266 oop oopDesc::decode_heap_oop_not_null(narrowOop v) {
 267   assert(!is_null(v), "narrow oop value can never be zero");
 268   address base = Universe::narrow_oop_base();
 269   int    shift = Universe::narrow_oop_shift();
 270   oop result = (oop)(void*)((uintptr_t)base + ((uintptr_t)v << shift));
 271   assert(check_obj_alignment(result), "address not aligned: " INTPTR_FORMAT, p2i((void*) result));
 272   return result;
 273 }
 274 
 275 oop oopDesc::decode_heap_oop(narrowOop v) {
 276   return is_null(v) ? (oop)NULL : decode_heap_oop_not_null(v);
 277 }
 278 
 279 narrowOop oopDesc::encode_heap_oop_not_null(oop v) {
 280   assert(!is_null(v), "oop value can never be zero");
 281   assert(check_obj_alignment(v), "Address not aligned");
 282   assert(Universe::heap()->is_in_reserved(v), "Address not in heap");
 283   address base = Universe::narrow_oop_base();
 284   int    shift = Universe::narrow_oop_shift();
 285   uint64_t  pd = (uint64_t)(pointer_delta((void*)v, (void*)base, 1));
 286   assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
 287   uint64_t result = pd >> shift;
 288   assert((result & CONST64(0xffffffff00000000)) == 0, "narrow oop overflow");
 289   assert(decode_heap_oop(result) == v, "reversibility");
 290   return (narrowOop)result;
 291 }
 292 
 293 narrowOop oopDesc::encode_heap_oop(oop v) {
 294   return (is_null(v)) ? (narrowOop)0 : encode_heap_oop_not_null(v);
 295 }
 296 
 297 narrowOop oopDesc::load_heap_oop(narrowOop* p) { return *p; }
 298 oop       oopDesc::load_heap_oop(oop* p)       { return *p; }
 299 
 300 void oopDesc::store_heap_oop(narrowOop* p, narrowOop v) { *p = v; }
 301 void oopDesc::store_heap_oop(oop* p, oop v)             { *p = v; }
 302 
 303 // Load and decode an oop out of the Java heap into a wide oop.
 304 oop oopDesc::load_decode_heap_oop_not_null(narrowOop* p) {
 305   return decode_heap_oop_not_null(load_heap_oop(p));
 306 }
 307 
 308 // Load and decode an oop out of the heap accepting null
 309 oop oopDesc::load_decode_heap_oop(narrowOop* p) {
 310   return decode_heap_oop(load_heap_oop(p));
 311 }
 312 
 313 oop oopDesc::load_decode_heap_oop_not_null(oop* p) { return *p; }
 314 oop oopDesc::load_decode_heap_oop(oop* p)          { return *p; }
 315 
 316 void oopDesc::encode_store_heap_oop_not_null(oop* p, oop v) { *p = v; }
 317 void oopDesc::encode_store_heap_oop(oop* p, oop v)          { *p = v; }
 318 
 319 // Encode and store a heap oop.
 320 void oopDesc::encode_store_heap_oop_not_null(narrowOop* p, oop v) {
 321   *p = encode_heap_oop_not_null(v);
 322 }
 323 
 324 // Encode and store a heap oop allowing for null.
 325 void oopDesc::encode_store_heap_oop(narrowOop* p, oop v) {
 326   *p = encode_heap_oop(v);
 327 }
 328 
 329 template <DecoratorSet decorators>
 330 inline oop oopDesc::obj_field_special(int offset) const             { return HeapAccess<decorators>::oop_load_at(as_oop(), offset); }
 331 inline oop  oopDesc::obj_field(int offset) const                    { return HeapAccess<>::oop_load_at(as_oop(), offset);  }
 332 
 333 inline void oopDesc::obj_field_put(int offset, oop value)           { HeapAccess<>::oop_store_at(as_oop(), offset, value); }
 334 
 335 inline jbyte oopDesc::byte_field(int offset) const                  { return HeapAccess<>::load_at(as_oop(), offset);  }
 336 inline void  oopDesc::byte_field_put(int offset, jbyte value)       { HeapAccess<>::store_at(as_oop(), offset, value); }
 337 
 338 inline jchar oopDesc::char_field(int offset) const                  { return HeapAccess<>::load_at(as_oop(), offset);  }
 339 inline void  oopDesc::char_field_put(int offset, jchar value)       { HeapAccess<>::store_at(as_oop(), offset, value); }
 340 
 341 inline jboolean oopDesc::bool_field(int offset) const               { return HeapAccess<>::load_at(as_oop(), offset);                }
 342 inline void     oopDesc::bool_field_put(int offset, jboolean value) { HeapAccess<>::store_at(as_oop(), offset, jboolean(value & 1)); }
 343 
 344 inline jshort oopDesc::short_field(int offset) const                { return HeapAccess<>::load_at(as_oop(), offset);  }
 345 inline void   oopDesc::short_field_put(int offset, jshort value)    { HeapAccess<>::store_at(as_oop(), offset, value); }
 346 
 347 inline jint oopDesc::int_field(int offset) const                    { return HeapAccess<>::load_at(as_oop(), offset);  }
 348 inline void oopDesc::int_field_put(int offset, jint value)          { HeapAccess<>::store_at(as_oop(), offset, value); }
 349 
 350 inline jlong oopDesc::long_field(int offset) const                  { return HeapAccess<>::load_at(as_oop(), offset);  }
 351 inline void  oopDesc::long_field_put(int offset, jlong value)       { HeapAccess<>::store_at(as_oop(), offset, value); }
 352 
 353 inline jfloat oopDesc::float_field(int offset) const                { return HeapAccess<>::load_at(as_oop(), offset);  }
 354 inline void   oopDesc::float_field_put(int offset, jfloat value)    { HeapAccess<>::store_at(as_oop(), offset, value); }
 355 
 356 inline jdouble oopDesc::double_field(int offset) const              { return HeapAccess<>::load_at(as_oop(), offset);  }
 357 inline void    oopDesc::double_field_put(int offset, jdouble value) { HeapAccess<>::store_at(as_oop(), offset, value); }
 358 
 359 bool oopDesc::is_locked() const {
 360   return mark()->is_locked();
 361 }
 362 
 363 bool oopDesc::is_unlocked() const {
 364   return mark()->is_unlocked();
 365 }
 366 
 367 bool oopDesc::has_bias_pattern() const {
 368   return mark()->has_bias_pattern();
 369 }
 370 
 371 // Used only for markSweep, scavenging
 372 bool oopDesc::is_gc_marked() const {
 373   return mark()->is_marked();
 374 }
 375 
 376 bool oopDesc::is_scavengable() const {
 377   return Universe::heap()->is_scavengable(oop(const_cast<oopDesc*>(this)));
 378 }
 379 
 380 // Used by scavengers
 381 bool oopDesc::is_forwarded() const {
 382   // The extra heap check is needed since the obj might be locked, in which case the
 383   // mark would point to a stack location and have the sentinel bit cleared
 384   return mark()->is_marked();
 385 }
 386 
 387 // Used by scavengers
 388 void oopDesc::forward_to(oop p) {
 389   assert(check_obj_alignment(p),
 390          "forwarding to something not aligned");
 391   assert(Universe::heap()->is_in_reserved(p),
 392          "forwarding to something not in heap");
 393   assert(!is_archive_object(oop(this)) &&
 394          !is_archive_object(p),
 395          "forwarding archive object");
 396   markOop m = markOopDesc::encode_pointer_as_mark(p);
 397   assert(m->decode_pointer() == p, "encoding must be reversable");
 398   set_mark(m);
 399 }
 400 
 401 // Used by parallel scavengers
 402 bool oopDesc::cas_forward_to(oop p, markOop compare) {
 403   assert(check_obj_alignment(p),
 404          "forwarding to something not aligned");
 405   assert(Universe::heap()->is_in_reserved(p),
 406          "forwarding to something not in heap");
 407   markOop m = markOopDesc::encode_pointer_as_mark(p);
 408   assert(m->decode_pointer() == p, "encoding must be reversable");
 409   return cas_set_mark(m, compare) == compare;
 410 }
 411 
 412 #if INCLUDE_ALL_GCS
 413 oop oopDesc::forward_to_atomic(oop p) {
 414   markOop oldMark = mark();
 415   markOop forwardPtrMark = markOopDesc::encode_pointer_as_mark(p);
 416   markOop curMark;
 417 
 418   assert(forwardPtrMark->decode_pointer() == p, "encoding must be reversable");
 419   assert(sizeof(markOop) == sizeof(intptr_t), "CAS below requires this.");
 420 
 421   while (!oldMark->is_marked()) {
 422     curMark = Atomic::cmpxchg(forwardPtrMark, &_mark, oldMark);
 423     assert(is_forwarded(), "object should have been forwarded");
 424     if (curMark == oldMark) {
 425       return NULL;
 426     }
 427     // If the CAS was unsuccessful then curMark->is_marked()
 428     // should return true as another thread has CAS'd in another
 429     // forwarding pointer.
 430     oldMark = curMark;
 431   }
 432   return forwardee();
 433 }
 434 #endif
 435 
 436 // Note that the forwardee is not the same thing as the displaced_mark.
 437 // The forwardee is used when copying during scavenge and mark-sweep.
 438 // It does need to clear the low two locking- and GC-related bits.
 439 oop oopDesc::forwardee() const {
 440   return (oop) mark()->decode_pointer();
 441 }
 442 
 443 // The following method needs to be MT safe.
 444 uint oopDesc::age() const {
 445   assert(!is_forwarded(), "Attempt to read age from forwarded mark");
 446   if (has_displaced_mark()) {
 447     return displaced_mark()->age();
 448   } else {
 449     return mark()->age();
 450   }
 451 }
 452 
 453 void oopDesc::incr_age() {
 454   assert(!is_forwarded(), "Attempt to increment age of forwarded mark");
 455   if (has_displaced_mark()) {
 456     set_displaced_mark(displaced_mark()->incr_age());
 457   } else {
 458     set_mark(mark()->incr_age());
 459   }
 460 }
 461 
 462 #if INCLUDE_ALL_GCS
 463 void oopDesc::pc_follow_contents(ParCompactionManager* cm) {
 464   klass()->oop_pc_follow_contents(this, cm);
 465 }
 466 
 467 void oopDesc::pc_update_contents(ParCompactionManager* cm) {
 468   Klass* k = klass();
 469   if (!k->is_typeArray_klass()) {
 470     // It might contain oops beyond the header, so take the virtual call.
 471     k->oop_pc_update_pointers(this, cm);
 472   }
 473   // Else skip it.  The TypeArrayKlass in the header never needs scavenging.
 474 }
 475 
 476 void oopDesc::ps_push_contents(PSPromotionManager* pm) {
 477   Klass* k = klass();
 478   if (!k->is_typeArray_klass()) {
 479     // It might contain oops beyond the header, so take the virtual call.
 480     k->oop_ps_push_contents(this, pm);
 481   }
 482   // Else skip it.  The TypeArrayKlass in the header never needs scavenging.
 483 }
 484 #endif // INCLUDE_ALL_GCS
 485 
 486 #define OOP_ITERATE_DEFN(OopClosureType, nv_suffix)                 \
 487                                                                     \
 488 void oopDesc::oop_iterate(OopClosureType* blk) {                    \
 489   klass()->oop_oop_iterate##nv_suffix(this, blk);                   \
 490 }                                                                   \
 491                                                                     \
 492 void oopDesc::oop_iterate(OopClosureType* blk, MemRegion mr) {      \
 493   klass()->oop_oop_iterate_bounded##nv_suffix(this, blk, mr);       \
 494 }
 495 
 496 #define OOP_ITERATE_SIZE_DEFN(OopClosureType, nv_suffix)            \
 497                                                                     \
 498 int oopDesc::oop_iterate_size(OopClosureType* blk) {                \
 499   Klass* k = klass();                                               \
 500   int size = size_given_klass(k);                                   \
 501   k->oop_oop_iterate##nv_suffix(this, blk);                         \
 502   return size;                                                      \
 503 }                                                                   \
 504                                                                     \
 505 int oopDesc::oop_iterate_size(OopClosureType* blk, MemRegion mr) {  \
 506   Klass* k = klass();                                               \
 507   int size = size_given_klass(k);                                   \
 508   k->oop_oop_iterate_bounded##nv_suffix(this, blk, mr);             \
 509   return size;                                                      \
 510 }
 511 
 512 int oopDesc::oop_iterate_no_header(OopClosure* blk) {
 513   // The NoHeaderExtendedOopClosure wraps the OopClosure and proxies all
 514   // the do_oop calls, but turns off all other features in ExtendedOopClosure.
 515   NoHeaderExtendedOopClosure cl(blk);
 516   return oop_iterate_size(&cl);
 517 }
 518 
 519 int oopDesc::oop_iterate_no_header(OopClosure* blk, MemRegion mr) {
 520   NoHeaderExtendedOopClosure cl(blk);
 521   return oop_iterate_size(&cl, mr);
 522 }
 523 
 524 #if INCLUDE_ALL_GCS
 525 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)       \
 526                                                                     \
 527 inline void oopDesc::oop_iterate_backwards(OopClosureType* blk) {   \
 528   klass()->oop_oop_iterate_backwards##nv_suffix(this, blk);         \
 529 }
 530 #else
 531 #define OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)
 532 #endif // INCLUDE_ALL_GCS
 533 
 534 #define ALL_OOPDESC_OOP_ITERATE(OopClosureType, nv_suffix)  \
 535   OOP_ITERATE_DEFN(OopClosureType, nv_suffix)               \
 536   OOP_ITERATE_SIZE_DEFN(OopClosureType, nv_suffix)          \
 537   OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix)
 538 
 539 ALL_OOP_OOP_ITERATE_CLOSURES_1(ALL_OOPDESC_OOP_ITERATE)
 540 ALL_OOP_OOP_ITERATE_CLOSURES_2(ALL_OOPDESC_OOP_ITERATE)
 541 
 542 intptr_t oopDesc::identity_hash() {
 543   // Fast case; if the object is unlocked and the hash value is set, no locking is needed
 544   // Note: The mark must be read into local variable to avoid concurrent updates.
 545   markOop mrk = mark();
 546   if (mrk->is_unlocked() && !mrk->has_no_hash()) {
 547     return mrk->hash();
 548   } else if (mrk->is_marked()) {
 549     return mrk->hash();
 550   } else {
 551     return slow_identity_hash();
 552   }
 553 }
 554 
 555 bool oopDesc::has_displaced_mark() const {
 556   return mark()->has_displaced_mark_helper();
 557 }
 558 
 559 markOop oopDesc::displaced_mark() const {
 560   return mark()->displaced_mark_helper();
 561 }
 562 
 563 void oopDesc::set_displaced_mark(markOop m) {
 564   mark()->set_displaced_mark_helper(m);
 565 }
 566 
 567 #endif // SHARE_VM_OOPS_OOP_INLINE_HPP