Reactor Lifecycle

A reactor has active and inactive states. While in an inactive state no sockets are active, no DNS calls are active, and no tasks are scheduled. Any of these may be true in an active state.

The normal reactor lifecycle is summarized in this state diagram:

Start

Calls to haka_mqtt.reactor.Reactor.start() can be used to activate an inactive reactor otherwise they have no effect.

Stop

Calls to haka_mqtt.reactor.Reactor.stop() may be used to at the earliest possible opportunity cleanly disconnect from a server.

Subscribe/Unsubscribe

Subscribe/unsubscribe calls made before a call to haka_mqtt.reactor.Reactor.stop() will have their associated packets delivered before the socket outgoing write channel is closed. Whether the packets are acknowledged on not depends on server implementation.

Publish

Calls made to publish before a call to haka_mqtt.reactor.Reactor.stop() will have the associated packets delivered before the socket’s outgoing write channel is closed. The server may or may not acknowledge QoS=1 publishes before closing the socket. QoS=2 packets may be acknowledge with a pubrec packet but the reactor will not acknowledge the pubrec packet with a pubrel since the outgoing socket stream would already have been closed. Any pubrel packets qeued before the call to stop will be delivered before the outgoing write channel is closed and may or may not be acknowledged by the server with a pubcomp.

Terminate

A haka_mqtt.reactor.Reactor.terminate() call prompty closes all haka-mqtt reactor resources and places the reactor into a stopped state. All schedule deadlines are promptly cancelled. All socket resources are promptly closed. Any asynchronous hostname lookups are cancelled. “Prompt” in this case means before the terminate call returns.