jdk-24/hotspot/src/share/vm/memory/space.inline.hpp

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 * version 2 for more details (a copy is included in the LICENSE file that
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 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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inline HeapWord* Space::block_start(const void* p) {
  return block_start_const(p);
}

inline HeapWord* OffsetTableContigSpace::allocate(size_t size) {
  HeapWord* res = ContiguousSpace::allocate(size);
  if (res != NULL) {
    _offsets.alloc_block(res, size);
  }
  return res;
}

// Because of the requirement of keeping "_offsets" up to date with the
// allocations, we sequentialize these with a lock.  Therefore, best if
// this is used for larger LAB allocations only.
inline HeapWord* OffsetTableContigSpace::par_allocate(size_t size) {
  MutexLocker x(&_par_alloc_lock);
  // This ought to be just "allocate", because of the lock above, but that
  // ContiguousSpace::allocate asserts that either the allocating thread
  // holds the heap lock or it is the VM thread and we're at a safepoint.
  // The best I (dld) could figure was to put a field in ContiguousSpace
  // meaning "locking at safepoint taken care of", and set/reset that
  // here.  But this will do for now, especially in light of the comment
  // above.  Perhaps in the future some lock-free manner of keeping the
  // coordination.
  HeapWord* res = ContiguousSpace::par_allocate(size);
  if (res != NULL) {
    _offsets.alloc_block(res, size);
  }
  return res;
}

inline HeapWord*
OffsetTableContigSpace::block_start_const(const void* p) const {
  return _offsets.block_start(p);
}

inline HeapWord* ContiguousSpace::concurrent_iteration_safe_limit()
{
  assert(_concurrent_iteration_safe_limit <= top(),
         "_concurrent_iteration_safe_limit update missed");
  return _concurrent_iteration_safe_limit;
}

inline void ContiguousSpace::set_concurrent_iteration_safe_limit(HeapWord* new_limit)
{
  assert(new_limit <= top(), "uninitialized objects in the safe range");
  _concurrent_iteration_safe_limit = new_limit;
}