When an async stream such as AsynchronousSocketStream is used in a synchronous manner, typically by the server monitor, it can leak buffers from the buffer pool when the stream is closed while waiting for a response. This can happen when the server monitor is interrupted.

In practice this happens rarely since the server monitor is only interrupted when it's closed, so the leak is not all that important. However, it makes it hard to write assertions about the absence of leaks when running integration tests.