Class SaltEvent

salt/utils/event.py:232–1057

Warning! Use the get_event function or the code will not be RAET compatible The base class used to manage salt events

class SaltEvent:
    """
    Warning! Use the get_event function or the code will not be
    RAET compatible
    The base class used to manage salt events
    """

    # Live SaltEvent instances tracked weakly so the at-fork handler can
    # drop ZMQ pub/push sockets and asyncio/tornado loops inherited by
    # any forked child.  Sharing a parent's subscriber across sibling
    # children races the SUB-side message dispatch and deadlocks the
    # asyncio loop the same way RemoteClient does -- see fileclient.py.
    _instances = weakref.WeakSet()
    _atfork_registered = False

    @classmethod
    def _register_atfork(cls):
        if cls._atfork_registered or not hasattr(os, "register_at_fork"):
            return
        os.register_at_fork(after_in_child=cls._after_fork_in_child)
        cls._atfork_registered = True

    @classmethod
    def _after_fork_in_child(cls):
        # Drop inherited ZMQ socket / IOLoop references without close():
        # close() would tear down FDs and asyncio loop state copied from
        # the parent and could affect the parent's bus.  Connections will
        # be lazily reopened by connect_pub() / connect_pull() on next
        # use.
        for inst in list(cls._instances):
            try:
                inst.subscriber = None
                inst.pusher = None
                inst.cpub = False
                inst.cpush = False
            except Exception:  # pylint: disable=broad-except
                pass

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.destroy()

    def __init__(
        self,
        node,
        sock_dir=None,
        opts=None,
        listen=True,
        io_loop=None,
        keep_loop=False,
        raise_errors=False,
    ):
        """
        :param IOLoop io_loop: Pass in an io_loop if you want asynchronous
                               operation for obtaining events. Eg use of
                               set_event_handler() API. Otherwise, operation