Win3mu's RangeAllocator

RangeAllocator.cs

// Manages allocations within an "address space".
public class RangeAllocator<T>
{
  // Constructor
  public RangeAllocator(int addressSpaceSize);

  // Info accessors
  public int AddressSpaceSize { get; set; }
  public int FreeSpace { get; }
  public int EntryCount { get; }

  // Defrag the heap, returns true if anything moved
  public bool Defrag();

  // Allocate
  public Range Alloc(int size, bool moveable, bool allowDefrag);
  public bool ReAlloc(Range allocation, int newSize, bool moveable, bool allocDefrag);
  public bool ReAllocInPlace(Range alloc, int newSize);
  public void Free(Range allocation);

  // Must be provided to allow move operations
  public IMoveListener MoveListener;

  // Publicly visible view on an allocation
  public abstract class Range
  {
      public abstract int Position { get; }
      public abstract int Size { get; }
      public abstract bool Moveable { get; }
      public T User;
      public int LockCount;
  }

  // Notify the client that a range is moving
  // The local heap listens to this to move the actual data
  // behind any allocations.
  public interface IMoveListener
  {
      void Move(Range user, int newPosition);
  }
}