Emulates the UNIX socketpair() system call on Windows. This function uses a trick with non-blocking sockets to prevent the need for a thread. A socketpair can be used as a full-duplex, select()able pipe on Windows.

winsocketpair.py

def socketpair(family=socket.AF_INET, type=socket.SOCK_STREAM, proto=0):
    """Emulate the Unix socketpair() function on Windows."""
    # We create a connected TCP socket. Note the trick with setblocking(0)
    # that prevents us from having to create a thread.
    lsock = socket.socket(family, type, proto)
    lsock.bind(('localhost', 0)) 
    lsock.listen(1)
    addr, port = lsock.getsockname()
    csock = socket.socket(family, type, proto)
    csock.setblocking(0)
    try:
        csock.connect((addr, port))
    except socket.error, e:
        if e.errno != errno.WSAEWOULDBLOCK:
            raise
    ssock, addr = lsock.accept()
    csock.setblocking(1)
    lsock.close()
    return (ssock, csock)

FWIW, now that .socketpair() support is in Python 3.5,
I published a backports.socketpair package on PyPi.

@mhills thank you!

Is this gist considered public domain?

Hi,

I am come from Python's socket module of a similar function socketpair() to this one.
Which has a URL refer to here.

Would anyone tell me, why socketpair requires a socket status back to blocked.
Namely, What the setblocking(1) at the last is used for ?

As I can understand the Event Loop of Python Asyncio is socketpair (with select/epoll/...) based,
but Python Asyncio works fine (nonblocked), thus confused me about setblocking(1).

Hello,

Could you please supply a license for your code?
(It's found in Python's socket.py,
https://github.com/python/cpython/blob/master/Lib/socketserver.py
which is why I am asking)
Thanks!

<removed for now, will relink later>