WSAEventSelect with FD_ACCEPT, recv returns WSAEWOULDBLOCK

Question

I'm trying to setup a socket that won't block on accept(...), using the following code:

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(("127.0.0.1", 1234))
event = win32event.CreateEvent(None, True, False, None)
win32file.WSAEventSelect(sock.fileno(), event, win32file.FD_ACCEPT)
sock.listen(5)
rc = win32event.WaitForSingleObject(event, win32event.INFINITE)

if not rc == win32event.WAIT_OBJECT_0:
    return

conn, addr = sock.accept()

while 1:
    data = conn.recv(1024)
    if not data: break
    conn.send(data)

conn.close()

When a client connects but there's no data, recv returns WSAEWOULDBLOCK. Reading MSDN explains this is the right behavior for non-blocking sockets but when using WSAEventSelect I only specified FD_ACCEPT, without FD_READ. Therefore I expect recv to block when there's no data, and to return with 0 when the connection was gracefully closed.

What am I doing wrong?

Answer 1

Solved this by: adding the following lines before accept:

win32file.WSAEventSelect(sock.fileno(), event, 0)
sock.setblocking(1)