poll crash sliently

test_poll.py

import pyuv
import socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(("www.sohu.com", 80))
rfile = sock.makefile('rb', -1)
wfile = sock.makefile('wb', 0)
loop = pyuv.Loop.default_loop()
rpoll = pyuv.Poll(loop, rfile.fileno())
def poll_read(poll, event, error):
    pass
def poll_write(poll, event, error):
    print "eee"
    pass
rpoll.start(pyuv.UV_READABLE, poll_read)
wpoll = pyuv.Poll(loop, wfile.fileno())
wpoll.start(pyuv.UV_WRITABLE, poll_write)
loop.run()
print "stop"