_socket3.py 文件源码

def socketpair(family=AF_INET, type=SOCK_STREAM, proto=0):
        if family == AF_INET:
            host = _LOCALHOST
        elif family == AF_INET6:
            host = _LOCALHOST_V6
        else:
            raise ValueError("Only AF_INET and AF_INET6 socket address families "
                             "are supported")
        if type != SOCK_STREAM:
            raise ValueError("Only SOCK_STREAM socket type is supported")
        if proto != 0:
            raise ValueError("Only protocol zero is supported")

        # We create a connected TCP socket. Note the trick with
        # setblocking(False) that prevents us from having to create a thread.
        lsock = socket(family, type, proto)
        try:
            lsock.bind((host, 0))
            lsock.listen(128)
            # On IPv6, ignore flow_info and scope_id
            addr, port = lsock.getsockname()[:2]
            csock = socket(family, type, proto)
            try:
                csock.setblocking(False)
                try:
                    csock.connect((addr, port))
                except (BlockingIOError, InterruptedError):
                    pass
                csock.setblocking(True)
                ssock, _ = lsock.accept()
            except:
                csock.close()
                raise
        finally:
            lsock.close()
        return (ssock, csock)