diff options
Diffstat (limited to 'src/console/zmq/green/poll.py')
-rwxr-xr-x | src/console/zmq/green/poll.py | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/src/console/zmq/green/poll.py b/src/console/zmq/green/poll.py new file mode 100755 index 00000000..8f016129 --- /dev/null +++ b/src/console/zmq/green/poll.py @@ -0,0 +1,95 @@ +import zmq +import gevent +from gevent import select + +from zmq import Poller as _original_Poller + + +class _Poller(_original_Poller): + """Replacement for :class:`zmq.Poller` + + Ensures that the greened Poller below is used in calls to + :meth:`zmq.Poller.poll`. + """ + _gevent_bug_timeout = 1.33 # minimum poll interval, for working around gevent bug + + def _get_descriptors(self): + """Returns three elements tuple with socket descriptors ready + for gevent.select.select + """ + rlist = [] + wlist = [] + xlist = [] + + for socket, flags in self.sockets: + if isinstance(socket, zmq.Socket): + rlist.append(socket.getsockopt(zmq.FD)) + continue + elif isinstance(socket, int): + fd = socket + elif hasattr(socket, 'fileno'): + try: + fd = int(socket.fileno()) + except: + raise ValueError('fileno() must return an valid integer fd') + else: + raise TypeError('Socket must be a 0MQ socket, an integer fd ' + 'or have a fileno() method: %r' % socket) + + if flags & zmq.POLLIN: + rlist.append(fd) + if flags & zmq.POLLOUT: + wlist.append(fd) + if flags & zmq.POLLERR: + xlist.append(fd) + + return (rlist, wlist, xlist) + + def poll(self, timeout=-1): + """Overridden method to ensure that the green version of + Poller is used. + + Behaves the same as :meth:`zmq.core.Poller.poll` + """ + + if timeout is None: + timeout = -1 + + if timeout < 0: + timeout = -1 + + rlist = None + wlist = None + xlist = None + + if timeout > 0: + tout = gevent.Timeout.start_new(timeout/1000.0) + + try: + # Loop until timeout or events available + rlist, wlist, xlist = self._get_descriptors() + while True: + events = super(_Poller, self).poll(0) + if events or timeout == 0: + return events + + # wait for activity on sockets in a green way + # set a minimum poll frequency, + # because gevent < 1.0 cannot be trusted to catch edge-triggered FD events + _bug_timeout = gevent.Timeout.start_new(self._gevent_bug_timeout) + try: + select.select(rlist, wlist, xlist) + except gevent.Timeout as t: + if t is not _bug_timeout: + raise + finally: + _bug_timeout.cancel() + + except gevent.Timeout as t: + if t is not tout: + raise + return [] + finally: + if timeout > 0: + tout.cancel() + |