Breaking ReadFile() blocking - Named Pipe (Windows API)

Question

To simplify, this is a situation where a NamedPipe SERVER is waiting for a NamedPipe CLIENT to write to the pipe (using WriteFile())

The Windows API that is blocking

Answer 1

Just use SetNamedPipeHandleState function https://docs.microsoft.com/en-us/windows/win32/api/namedpipeapi/nf-namedpipeapi-setnamedpipehandlestate

Use the PIPE_NOWAIT flag when calling this function.

hNamedPipe should be the handle that returned from CreateFile function.

After that, the call to ReadFile will not block the thread when no data available.