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