Python select.kqueue() Examples

def DefaultSelector():
    """ This function serves as a first call for DefaultSelector to
    detect if the select module is being monkey-patched incorrectly
    by eventlet, greenlet, and preserve proper behavior. """
    global _DEFAULT_SELECTOR
    if _DEFAULT_SELECTOR is None:
        if _can_allocate('kqueue'):
            _DEFAULT_SELECTOR = KqueueSelector
        elif _can_allocate('epoll'):
            _DEFAULT_SELECTOR = EpollSelector
        elif _can_allocate('poll'):
            _DEFAULT_SELECTOR = PollSelector
        elif hasattr(select, 'select'):
            _DEFAULT_SELECTOR = SelectSelector
        else:  # Platform-specific: AppEngine
            raise ValueError('Platform does not have a selector')
    return _DEFAULT_SELECTOR() 

def DefaultSelector():
    """ This function serves as a first call for DefaultSelector to
    detect if the select module is being monkey-patched incorrectly
    by eventlet, greenlet, and preserve proper behavior. """
    global _DEFAULT_SELECTOR
    if _DEFAULT_SELECTOR is None:
        if _can_allocate('kqueue'):
            _DEFAULT_SELECTOR = KqueueSelector
        elif _can_allocate('epoll'):
            _DEFAULT_SELECTOR = EpollSelector
        elif _can_allocate('poll'):
            _DEFAULT_SELECTOR = PollSelector
        elif hasattr(select, 'select'):
            _DEFAULT_SELECTOR = SelectSelector
        else:  # Platform-specific: AppEngine
            raise ValueError('Platform does not have a selector')
    return _DEFAULT_SELECTOR() 

def _can_allocate(struct):
    """ Checks that select structs can be allocated by the underlying
    operating system, not just advertised by the select module. We don't
    check select() because we'll be hopeful that most platforms that
    don't have it available will not advertise it. (ie: GAE) """
    try:
        # select.poll() objects won't fail until used.
        if struct == 'poll':
            p = select.poll()
            p.poll(0)

        # All others will fail on allocation.
        else:
            getattr(select, struct)().close()
        return True
    except (OSError, AttributeError) as e:
        return False


# Choose the best implementation, roughly:
# kqueue == epoll > poll > select. Devpoll not supported. (See above)
# select() also can't accept a FD > FD_SETSIZE (usually around 1024) 

def DefaultSelector():
    """ This function serves as a first call for DefaultSelector to
    detect if the select module is being monkey-patched incorrectly
    by eventlet, greenlet, and preserve proper behavior. """
    global _DEFAULT_SELECTOR
    if _DEFAULT_SELECTOR is None:
        if _can_allocate('kqueue'):
            _DEFAULT_SELECTOR = KqueueSelector
        elif _can_allocate('epoll'):
            _DEFAULT_SELECTOR = EpollSelector
        elif _can_allocate('poll'):
            _DEFAULT_SELECTOR = PollSelector
        elif hasattr(select, 'select'):
            _DEFAULT_SELECTOR = SelectSelector
        else:  # Platform-specific: AppEngine
            raise ValueError('Platform does not have a selector')
    return _DEFAULT_SELECTOR() 

def _can_allocate(struct):
    """ Checks that select structs can be allocated by the underlying
    operating system, not just advertised by the select module. We don't
    check select() because we'll be hopeful that most platforms that
    don't have it available will not advertise it. (ie: GAE) """
    try:
        # select.poll() objects won't fail until used.
        if struct == 'poll':
            p = select.poll()
            p.poll(0)

        # All others will fail on allocation.
        else:
            getattr(select, struct)().close()
        return True
    except (OSError, AttributeError) as e:
        return False


# Choose the best implementation, roughly:
# kqueue == epoll > poll > select. Devpoll not supported. (See above)
# select() also can't accept a FD > FD_SETSIZE (usually around 1024) 

def _can_allocate(struct):
    """ Checks that select structs can be allocated by the underlying
    operating system, not just advertised by the select module. We don't
    check select() because we'll be hopeful that most platforms that
    don't have it available will not advertise it. (ie: GAE) """
    try:
        # select.poll() objects won't fail until used.
        if struct == 'poll':
            p = select.poll()
            p.poll(0)

        # All others will fail on allocation.
        else:
            getattr(select, struct)().close()
        return True
    except (OSError, AttributeError) as e:
        return False


# Choose the best implementation, roughly:
# kqueue == epoll > poll > select. Devpoll not supported. (See above)
# select() also can't accept a FD > FD_SETSIZE (usually around 1024) 

def DefaultSelector():
    """This function serves as a first call for DefaultSelector to detect.

    It is for when the select module is being monkey-patched incorrectly by eventlet, greenlet,
    and preserve proper behavior.
    """
    global _DEFAULT_SELECTOR
    if _DEFAULT_SELECTOR is None:
        if _can_allocate('kqueue'):
            _DEFAULT_SELECTOR = KqueueSelector
        elif _can_allocate('epoll'):
            _DEFAULT_SELECTOR = EpollSelector
        elif _can_allocate('poll'):
            _DEFAULT_SELECTOR = PollSelector
        elif hasattr(select, 'select'):
            _DEFAULT_SELECTOR = SelectSelector
        else:  # Platform-specific: AppEngine
            raise ValueError('Platform does not have a selector')
    return _DEFAULT_SELECTOR() 

def _can_allocate(struct):
    """ Checks that select structs can be allocated by the underlying
    operating system, not just advertised by the select module. We don't
    check select() because we'll be hopeful that most platforms that
    don't have it available will not advertise it. (ie: GAE) """
    try:
        # select.poll() objects won't fail until used.
        if struct == 'poll':
            p = select.poll()
            p.poll(0)

        # All others will fail on allocation.
        else:
            getattr(select, struct)().close()
        return True
    except (OSError, AttributeError) as e:
        return False


# Choose the best implementation, roughly:
# kqueue == epoll > poll > select. Devpoll not supported. (See above)
# select() also can't accept a FD > FD_SETSIZE (usually around 1024) 

def _can_allocate(struct):
    """Checks that select structs can be allocated by the underlying operating system.

    Otherwise it could be just advertised by the select module. We don't check select() because we'll be hopeful
    that most platforms that don't have it available will not advertise it. (ie: GAE).
    """
    try:
        # select.poll() objects won't fail until used.
        if struct == 'poll':
            p = select.poll()
            p.poll(0)

        # All others will fail on allocation.
        else:
            getattr(select, struct)().close()
        return True
    except (OSError, AttributeError):
        return False


# Choose the best implementation, roughly:
# kqueue == epoll > poll > select. Devpoll not supported. (See above)
# select() also can't accept a FD > FD_SETSIZE (usually around 1024) 

def DefaultSelector():
    """ This function serves as a first call for DefaultSelector to
    detect if the select module is being monkey-patched incorrectly
    by eventlet, greenlet, and preserve proper behavior. """
    global _DEFAULT_SELECTOR
    if _DEFAULT_SELECTOR is None:
        if _can_allocate('kqueue'):
            _DEFAULT_SELECTOR = KqueueSelector
        elif _can_allocate('epoll'):
            _DEFAULT_SELECTOR = EpollSelector
        elif _can_allocate('poll'):
            _DEFAULT_SELECTOR = PollSelector
        elif hasattr(select, 'select'):
            _DEFAULT_SELECTOR = SelectSelector
        else:  # Platform-specific: AppEngine
            raise ValueError('Platform does not have a selector')
    return _DEFAULT_SELECTOR() 

def poll(self, timeout):
        kevents = self._kqueue.control(None, 1000, timeout)
        events = {}
        for kevent in kevents:
            fd = kevent.ident
            if kevent.filter == select.KQ_FILTER_READ:
                events[fd] = events.get(fd, 0) | IOLoop.READ
            if kevent.filter == select.KQ_FILTER_WRITE:
                if kevent.flags & select.KQ_EV_EOF:
                    # If an asynchronous connection is refused, kqueue
                    # returns a write event with the EOF flag set.
                    # Turn this into an error for consistency with the
                    # other IOLoop implementations.
                    # Note that for read events, EOF may be returned before
                    # all data has been consumed from the socket buffer,
                    # so we only check for EOF on write events.
                    events[fd] = IOLoop.ERROR
                else:
                    events[fd] = events.get(fd, 0) | IOLoop.WRITE
            if kevent.flags & select.KQ_EV_ERROR:
                events[fd] = events.get(fd, 0) | IOLoop.ERROR
        return events.items() 

def __init__(self):
        if hasattr(select, 'epoll'):
            self._impl = select.epoll()
            model = 'epoll'
        elif hasattr(select, 'kqueue'):
            self._impl = KqueueLoop()
            model = 'kqueue'
        elif hasattr(select, 'select'):
            self._impl = SelectLoop()
            model = 'select'
        else:
            raise Exception('can not find any available functions in select '
                            'package')
        self._fdmap = {}  # (f, handler)
        self._last_time = time.time()
        self._periodic_callbacks = []
        self._stopping = False
        logging.debug('using event model: %s', model) 

def test_issue30058(self):
        # changelist must be an iterable
        kq = select.kqueue()
        a, b = socket.socketpair()
        ev = select.kevent(a, select.KQ_FILTER_READ, select.KQ_EV_ADD | select.KQ_EV_ENABLE)

        kq.control([ev], 0)
        # not a list
        kq.control((ev,), 0)
        # __len__ is not consistent with __iter__
        class BadList:
            def __len__(self):
                return 0
            def __iter__(self):
                for i in range(100):
                    yield ev
        kq.control(BadList(), 0)
        # doesn't have __len__
        kq.control(iter([ev]), 0)

        a.close()
        b.close()
        kq.close() 

def poll(self, timeout=None):
        events = self.kqueue.control(self.events, 128, timeout)
        rv = []
        for ev in events:
            obj = self.event_to_object.get(ev.ident)
            if obj is None:
                # It happens surprisingly frequently that kqueue returns
                # write events things no longer in the kqueue.  Not sure
                # why
                continue
            if ev.filter == select.KQ_FILTER_READ:
                rv.append((obj, 'read'))
            elif ev.filter == select.KQ_FILTER_WRITE:
                rv.append((obj, 'write'))
            if ev.flags & select.KQ_EV_EOF:
                rv.append((obj, 'close'))
        return rv 

def _can_allocate(struct):
    """ Checks that select structs can be allocated by the underlying
    operating system, not just advertised by the select module. We don't
    check select() because we'll be hopeful that most platforms that
    don't have it available will not advertise it. (ie: GAE) """
    try:
        # select.poll() objects won't fail until used.
        if struct == 'poll':
            p = select.poll()
            p.poll(0)

        # All others will fail on allocation.
        else:
            getattr(select, struct)().close()
        return True
    except (OSError, AttributeError) as e:
        return False


# Choose the best implementation, roughly:
# kqueue == epoll > poll > select. Devpoll not supported. (See above)
# select() also can't accept a FD > FD_SETSIZE (usually around 1024) 

def poll(self, timeout):
        kevents = self._kqueue.control(None, 1000, timeout)
        events = {}
        for kevent in kevents:
            fd = kevent.ident
            if kevent.filter == select.KQ_FILTER_READ:
                events[fd] = events.get(fd, 0) | IOLoop.READ
            if kevent.filter == select.KQ_FILTER_WRITE:
                if kevent.flags & select.KQ_EV_EOF:
                    # If an asynchronous connection is refused, kqueue
                    # returns a write event with the EOF flag set.
                    # Turn this into an error for consistency with the
                    # other IOLoop implementations.
                    # Note that for read events, EOF may be returned before
                    # all data has been consumed from the socket buffer,
                    # so we only check for EOF on write events.
                    events[fd] = IOLoop.ERROR
                else:
                    events[fd] = events.get(fd, 0) | IOLoop.WRITE
            if kevent.flags & select.KQ_EV_ERROR:
                events[fd] = events.get(fd, 0) | IOLoop.ERROR
        return events.items() 

def _can_allocate(struct):
    """ Checks that select structs can be allocated by the underlying
    operating system, not just advertised by the select module. We don't
    check select() because we'll be hopeful that most platforms that
    don't have it available will not advertise it. (ie: GAE) """
    try:
        # select.poll() objects won't fail until used.
        if struct == 'poll':
            p = select.poll()
            p.poll(0)

        # All others will fail on allocation.
        else:
            getattr(select, struct)().close()
        return True
    except (OSError, AttributeError) as e:
        return False


# Choose the best implementation, roughly:
# kqueue == epoll > poll > select. Devpoll not supported. (See above)
# select() also can't accept a FD > FD_SETSIZE (usually around 1024) 

def DefaultSelector():
    """ This function serves as a first call for DefaultSelector to
    detect if the select module is being monkey-patched incorrectly
    by eventlet, greenlet, and preserve proper behavior. """
    global _DEFAULT_SELECTOR
    if _DEFAULT_SELECTOR is None:
        if _can_allocate('kqueue'):
            _DEFAULT_SELECTOR = KqueueSelector
        elif _can_allocate('epoll'):
            _DEFAULT_SELECTOR = EpollSelector
        elif _can_allocate('poll'):
            _DEFAULT_SELECTOR = PollSelector
        elif hasattr(select, 'select'):
            _DEFAULT_SELECTOR = SelectSelector
        else:  # Platform-specific: AppEngine
            raise ValueError('Platform does not have a selector')
    return _DEFAULT_SELECTOR() 

def _can_allocate(struct):
    """ Checks that select structs can be allocated by the underlying
    operating system, not just advertised by the select module. We don't
    check select() because we'll be hopeful that most platforms that
    don't have it available will not advertise it. (ie: GAE) """
    try:
        # select.poll() objects won't fail until used.
        if struct == 'poll':
            p = select.poll()
            p.poll(0)

        # All others will fail on allocation.
        else:
            getattr(select, struct)().close()
        return True
    except (OSError, AttributeError) as e:
        return False


# Choose the best implementation, roughly:
# kqueue == epoll > poll > select. Devpoll not supported. (See above)
# select() also can't accept a FD > FD_SETSIZE (usually around 1024) 

def poll(self, timeout):
        kevents = self._kqueue.control(None, 1000, timeout)
        events = {}
        for kevent in kevents:
            fd = kevent.ident
            if kevent.filter == select.KQ_FILTER_READ:
                events[fd] = events.get(fd, 0) | IOLoop.READ
            if kevent.filter == select.KQ_FILTER_WRITE:
                if kevent.flags & select.KQ_EV_EOF:
                    # If an asynchronous connection is refused, kqueue
                    # returns a write event with the EOF flag set.
                    # Turn this into an error for consistency with the
                    # other IOLoop implementations.
                    # Note that for read events, EOF may be returned before
                    # all data has been consumed from the socket buffer,
                    # so we only check for EOF on write events.
                    events[fd] = IOLoop.ERROR
                else:
                    events[fd] = events.get(fd, 0) | IOLoop.WRITE
            if kevent.flags & select.KQ_EV_ERROR:
                events[fd] = events.get(fd, 0) | IOLoop.ERROR
        return events.items() 

def poll(self, timeout):
        kevents = self._kqueue.control(None, 1000, timeout)
        events = {}
        for kevent in kevents:
            fd = kevent.ident
            if kevent.filter == select.KQ_FILTER_READ:
                events[fd] = events.get(fd, 0) | IOLoop.READ
            if kevent.filter == select.KQ_FILTER_WRITE:
                if kevent.flags & select.KQ_EV_EOF:
                    # If an asynchronous connection is refused, kqueue
                    # returns a write event with the EOF flag set.
                    # Turn this into an error for consistency with the
                    # other IOLoop implementations.
                    # Note that for read events, EOF may be returned before
                    # all data has been consumed from the socket buffer,
                    # so we only check for EOF on write events.
                    events[fd] = IOLoop.ERROR
                else:
                    events[fd] = events.get(fd, 0) | IOLoop.WRITE
            if kevent.flags & select.KQ_EV_ERROR:
                events[fd] = events.get(fd, 0) | IOLoop.ERROR
        return events.items() 

def _can_allocate(struct):
    """ Checks that select structs can be allocated by the underlying
    operating system, not just advertised by the select module. We don't
    check select() because we'll be hopeful that most platforms that
    don't have it available will not advertise it. (ie: GAE) """
    try:
        # select.poll() objects won't fail until used.
        if struct == 'poll':
            p = select.poll()
            p.poll(0)

        # All others will fail on allocation.
        else:
            getattr(select, struct)().close()
        return True
    except (OSError, AttributeError) as e:
        return False


# Choose the best implementation, roughly:
# kqueue == epoll > poll > select. Devpoll not supported. (See above)
# select() also can't accept a FD > FD_SETSIZE (usually around 1024) 

def DefaultSelector():
    """ This function serves as a first call for DefaultSelector to
    detect if the select module is being monkey-patched incorrectly
    by eventlet, greenlet, and preserve proper behavior. """
    global _DEFAULT_SELECTOR
    if _DEFAULT_SELECTOR is None:
        if _can_allocate('kqueue'):
            _DEFAULT_SELECTOR = KqueueSelector
        elif _can_allocate('epoll'):
            _DEFAULT_SELECTOR = EpollSelector
        elif _can_allocate('poll'):
            _DEFAULT_SELECTOR = PollSelector
        elif hasattr(select, 'select'):
            _DEFAULT_SELECTOR = SelectSelector
        else:  # Platform-specific: AppEngine
            raise ValueError('Platform does not have a selector')
    return _DEFAULT_SELECTOR() 

def _can_allocate(struct):
    """ Checks that select structs can be allocated by the underlying
    operating system, not just advertised by the select module. We don't
    check select() because we'll be hopeful that most platforms that
    don't have it available will not advertise it. (ie: GAE) """
    try:
        # select.poll() objects won't fail until used.
        if struct == 'poll':
            p = select.poll()
            p.poll(0)

        # All others will fail on allocation.
        else:
            getattr(select, struct)().close()
        return True
    except (OSError, AttributeError) as e:
        return False


# Choose the best implementation, roughly:
# kqueue == epoll > poll > select. Devpoll not supported. (See above)
# select() also can't accept a FD > FD_SETSIZE (usually around 1024) 

def DefaultSelector():
    """ This function serves as a first call for DefaultSelector to
    detect if the select module is being monkey-patched incorrectly
    by eventlet, greenlet, and preserve proper behavior. """
    global _DEFAULT_SELECTOR
    if _DEFAULT_SELECTOR is None:
        if _can_allocate('kqueue'):
            _DEFAULT_SELECTOR = KqueueSelector
        elif _can_allocate('epoll'):
            _DEFAULT_SELECTOR = EpollSelector
        elif _can_allocate('poll'):
            _DEFAULT_SELECTOR = PollSelector
        elif hasattr(select, 'select'):
            _DEFAULT_SELECTOR = SelectSelector
        else:  # Platform-specific: AppEngine
            raise ValueError('Platform does not have a selector')
    return _DEFAULT_SELECTOR() 

def poll(self, timeout):
        kevents = self._kqueue.control(None, 1000, timeout)
        events = {}
        for kevent in kevents:
            fd = kevent.ident
            if kevent.filter == select.KQ_FILTER_READ:
                events[fd] = events.get(fd, 0) | IOLoop.READ
            if kevent.filter == select.KQ_FILTER_WRITE:
                if kevent.flags & select.KQ_EV_EOF:
                    # If an asynchronous connection is refused, kqueue
                    # returns a write event with the EOF flag set.
                    # Turn this into an error for consistency with the
                    # other IOLoop implementations.
                    # Note that for read events, EOF may be returned before
                    # all data has been consumed from the socket buffer,
                    # so we only check for EOF on write events.
                    events[fd] = IOLoop.ERROR
                else:
                    events[fd] = events.get(fd, 0) | IOLoop.WRITE
            if kevent.flags & select.KQ_EV_ERROR:
                events[fd] = events.get(fd, 0) | IOLoop.ERROR
        return events.items() 

def queue_event(self, event):
        """
        Handles queueing a single event object.

        :param event:
            An instance of :class:`watchdog.events.FileSystemEvent`
            or a subclass.
        """
        # Handles all the book keeping for queued events.
        # We do not need to fire moved/deleted events for all subitems in
        # a directory tree here, because this function is called by kqueue
        # for all those events anyway.
        EventEmitter.queue_event(self, event)
        if event.event_type == EVENT_TYPE_CREATED:
            self._register_kevent(event.src_path, event.is_directory)
        elif event.event_type == EVENT_TYPE_MOVED:
            self._unregister_kevent(event.src_path)
            self._register_kevent(event.dest_path, event.is_directory)
        elif event.event_type == EVENT_TYPE_DELETED:
            self._unregister_kevent(event.src_path) 

def __init__(self):
        if hasattr(select, 'epoll'):
            self._impl = select.epoll()
            model = 'epoll'
        elif hasattr(select, 'kqueue'):
            self._impl = KqueueLoop()
            model = 'kqueue'
        elif hasattr(select, 'select'):
            self._impl = SelectLoop()
            model = 'select'
        else:
            raise Exception('can not find any available functions in select '
                            'package')
        self._fdmap = {}  # (f, handler)
        self._last_time = time.time()
        self._periodic_callbacks = []
        self._stopping = False
        logging.debug('using event model: %s', model) 

def _can_allocate(struct):
    """ Checks that select structs can be allocated by the underlying
    operating system, not just advertised by the select module. We don't
    check select() because we'll be hopeful that most platforms that
    don't have it available will not advertise it. (ie: GAE) """
    try:
        # select.poll() objects won't fail until used.
        if struct == 'poll':
            p = select.poll()
            p.poll(0)

        # All others will fail on allocation.
        else:
            getattr(select, struct)().close()
        return True
    except (OSError, AttributeError) as e:
        return False


# Choose the best implementation, roughly:
# kqueue == epoll > poll > select. Devpoll not supported. (See above)
# select() also can't accept a FD > FD_SETSIZE (usually around 1024) 

def DefaultSelector():
    """ This function serves as a first call for DefaultSelector to
    detect if the select module is being monkey-patched incorrectly
    by eventlet, greenlet, and preserve proper behavior. """
    global _DEFAULT_SELECTOR
    if _DEFAULT_SELECTOR is None:
        if _can_allocate('kqueue'):
            _DEFAULT_SELECTOR = KqueueSelector
        elif _can_allocate('epoll'):
            _DEFAULT_SELECTOR = EpollSelector
        elif _can_allocate('poll'):
            _DEFAULT_SELECTOR = PollSelector
        elif hasattr(select, 'select'):
            _DEFAULT_SELECTOR = SelectSelector
        else:  # Platform-specific: AppEngine
            raise ValueError('Platform does not have a selector')
    return _DEFAULT_SELECTOR()