p.py

import pyuv
import signal
import socket


class SignalWaker(object):

    def __init__(self):
        # Based on Zope async.py: http://svn.zope.org/zc.ngi/trunk/src/zc/ngi/async.py

        self.writer = socket.socket()
        # Disable buffering -- pulling the trigger sends 1 byte,
        # and we want that sent immediately, to wake up ASAP.
        self.writer.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)

        count = 0
        while True:
            count += 1
            # Bind to a local port; for efficiency, let the OS pick
            # a free port for us.
            # Unfortunately, stress tests showed that we may not
            # be able to connect to that port ("Address already in
            # use") despite that the OS picked it.  This appears
            # to be a race bug in the Windows socket implementation.
            # So we loop until a connect() succeeds (almost always
            # on the first try).  See the long thread at
            # http://mail.zope.org/pipermail/zope/2005-July/160433.html
            # for hideous details.
            a = socket.socket()
            a.bind(("127.0.0.1", 0))
            a.listen(1)
            connect_address = a.getsockname()
            try:
                self.writer.connect(connect_address)
            except socket.error:
                if count >= 10:  # I've never seen it go above 2
                    a.close()
                    self.writer.close()
                    raise socket.error("Cannot bind socket pair")
                # Close `a` and try again
                a.close()
            else:
                # success
                break

        self.reader, addr = a.accept()
        self.reader.setblocking(0)
        self.writer.setblocking(0)
        a.close()

    def read_fileno(self):
        return self.reader.fileno()

    def write_fileno(self):
        return self.writer.fileno()

    def consume(self):
        try:
            while True:
                result = self.reader.recv(1024)
                if not result:
                    break
        except (IOError, socket.error):
            pass

    def close(self):
        self.reader.close()
        self.writer.close()


waker = SignalWaker()
signal.set_wakeup_fd(waker.write_fileno())

def poll_cb(*args):
    print "poll_cb"
    waker.consume()

def cb(*args):
    print "aaaaa"


loop = pyuv.Loop.default_loop()

p = pyuv.Prepare(loop)
p.start(cb)

signal_poller = pyuv.Poll(loop, waker.read_fileno())
signal_poller.unref()
signal_poller.start(pyuv.UV_READABLE, poll_cb)

loop.run()