/// <summary>
/// Creates a lane at specific slot with the size given by the settings NextCapacity callback.
/// The slot must be null or Disposed.
/// </summary>
/// <param name="index">The index of the lane in the highway.</param>
/// <returns>The newly created lane instance or null if fails.</returns>
/// <exception cref="MemoryLaneException">Thresholds are reached:
/// MaxLanesCountReached or MaxTotalAllocBytesReached</exception>
public MemoryLane ReopenLane(int index)
{
// [i] The Allocation procedure will never look back at null slots when expanding
// thus there is no competition that may require locking.
if (Lanes.AppendIndex < index)
{
return(null);
}
var lane = Lanes[index];
if (lane == null || lane.IsDisposed)
{
var newLane = allocLane(settings.NextCapacity(index), true);
// In case that multiple threads attempt to reopen the same slot
if (Lanes.CAS(index, newLane, lane) != lane)
{
newLane.Dispose();
}
return(Lanes[index]);
}
else
{
return(null);
}
}