Unbuffered Overlapped IO in .NET (continued)

See the first article about overlapped IO.
As promised, I've created Buffered version of OverlappedStream. It has a byte[] buffer instead of unmanaged IntPtr, as there are no restrictions on memory alignment when FILE_FLAG_NO_BUFFERING is not used.
Also, in unbuffered version both WriteFileGather and ReadFileScatted functions were implemented. The restrictions for buffer size and alignment are different for Gather/Scatter operations: buffers should be of system page size and have the same alignment. OverlappedStreamUnbuffered.SystemPageSize property returns this value and it has to be used for buffer allocations.

Some examples

OverlappedStreamUnbuffered stream = new OverlappedStreamUnbuffered(
 path, 
 System.IO.FileMode.OpenOrCreate,
 System.IO.FileAccess.ReadWrite, 
 System.IO.FileShare.Read, 
 OverlappedStreamUnbuffered.UnbufferedFileOptions.None);

IntPtr[] buffers = new IntPtr[BUFFERS];
for (int i = 0; i < buffers.Length; i++)
{
 // allocate aligned buffers with VirtualAlloc or custom class
 buffers[i] = UnmanagedBufferPool.Alloc((int)OverlappedStreamUnbuffered.SystemPageSize);
}

IAsyncResult ar = stream.BeginReadScatter(buffers, startAddr, null, null);

uint bytesRead = OverlappedStream.EndOperation(ar, throwOnError);
// it is also possible to use more common syntax:
// stream.EndRead(ar);

Final notes

Asynchronous file access is often tricky, same as any multithreaded programming. One of non-obvious behaviours is that thread exit aborts pending IO operations started in this thread. It is well described here: http://www.beefycode.com/post/Overlapped-IO-Aborted-by-Terminating-Thread.aspx.
Therefore always wait for completion of all async operations even if they are initiated from a thread pool thread.

Full source code can be found on https://overlappedstream.codeplex.com/