mahos.node.comm.Context

class mahos.node.comm.Context(context: 'Context' | zmq.Context | None = None, poll_timeout_ms: int | None = None, linger_ms: int | None = None)

The communication context for mahos nodes.

Parameters:

• context – if passed, internal ZMQ context is shared.

• poll_timeout_ms – polling timeout in milliseconds.

Current implementation is based on ZMQ.

Communication is divided into two classes: 1. Inbound (rep, sub, broker) 2. Outbound (req, pub)

When adding inbound communication, register a function handler. The handler is called when an inbound message is received. The poll() method polls and handles all registered inbound messages. (So, users don’t have to care about it.)

When adding outbound communication, a sender object (Requester or Publisher) is returned. Through that object, users can send messages (and receive replies for Requester) at their own timing.

Note that context itself is thread-safe, but derived objects (ZMQ sockets) are not. Let’s consider a use case: You start a sub-thread for inbound message polling (in a loop), and use main-thread for outbound message sending (and provide API to get inbound message, etc.). In this case, only sub-thread should add inbound messages and use poll() method; and only main-thread should add outbound messages and use sender objects. See mahos.node.client for example implementations.

__init__(context: 'Context' | zmq.Context | None = None, poll_timeout_ms: int | None = None, linger_ms: int | None = None)

Methods

__init__([context, poll_timeout_ms, linger_ms])
add_broker(xpub_endpoint, xsub_endpoint[, ...])	Add broker (xpub/xsub) handlers.
add_pub(endpoint, topic[, logger])	Add and return a Publisher.
add_pub_handler(endpoint[, root_topic])	Add PUBHandler for logging.
add_rep(endpoint[, handler, req_type])	Add rep handler.
add_req(endpoint[, timeout_ms, rep_type, logger])	Add and return a Requester.
add_sub(endpoint[, topic, handler, ...])	Add sub handler.
close([close_zmq_ctx])	Close this context.
poll()	Poll inbound sockets and call corresponding handlers.
zmq_context()	Get internal ZMQ context.