Question

I was wondering what happens if there are more than one thread waiting for data to be available using System.Net.Sockets.NetworkStream.Read:

 numberOfBytesRead = myNetworkStream.Read(myReadBuffer, 0, myReadBuffer.Length);

where myNetworkStream is shared. When data is available, does only one thread see it or all the threads?

Answer 1

From the documentation:

Use the Write and Read methods for simple single thread synchronous blocking I/O. If you want to process your I/O using separate threads, consider using the BeginWrite and EndWrite methods, or the BeginRead and EndRead methods for communication.

…

Read and write operations can be performed simultaneously on an instance of the NetworkStream class without the need for synchronization. As long as there is one unique thread for the write operations and one unique thread for the read operations, there will be no cross-interference between read and write threads and no synchronization is required.

So I would say behavior is undefined.