/// <summary>
/// Allocate a new swapper id for the given <seealso cref="PageSwapper"/>.
/// </summary>
internal int Allocate(PageSwapper swapper)
{
lock (this)
{
SwapperMapping[] swapperMappings = this._swapperMappings;
// First look for an available freed slot.
lock ( _free )
{
if (!_free.Empty)
{
int id = _free.intIterator().next();
_free.remove(id);
swapperMappings[id] = new SwapperMapping(id, swapper);
this._swapperMappings = swapperMappings; // Volatile store synchronizes-with loads in getters.
return(id);
}
}
// No free slot was found above, so we extend the array to make room for a new slot.
int id = swapperMappings.Length;
if (id + 1 > _maxSwapperId)
{
throw new System.InvalidOperationException("All swapper ids are allocated: " + _maxSwapperId);
}
swapperMappings = Arrays.copyOf(swapperMappings, id + 1);
swapperMappings[id] = new SwapperMapping(id, swapper);
this._swapperMappings = swapperMappings; // Volatile store synchronizes-with loads in getters.
return(id);
}
}
private bool NextFromTxState()
{
if (_txTypeIterator == null && !_txTypes.Empty)
{
_txTypeIterator = _txTypes.intIterator();
//here it may be tempting to do txTypes.clear()
//however that will also clear the iterator
}
if (_txTypeIterator != null && _txTypeIterator.hasNext())
{
_storeCursor.setCurrent(_txTypeIterator.next(), NO_ID, NO_ID, NO_ID);
return(true);
}
return(false);
}