3

Are there any MQTT libraries that do not block while connecting?

I'm currently using PubSubClient, and the connection part contains this code: https://github.com/knolleary/pubsubclient/blob/master/src/PubSubClient.cpp

        while (!_client->available()) {
            unsigned long t = millis();
            if (t-lastInActivity >= ((int32_t) MQTT_SOCKET_TIMEOUT*1000UL)) {
                _state = MQTT_CONNECTION_TIMEOUT;
                _client->stop();
                return false;
            }
        }

I'd like my main loop to continue, or a callback to be called, while the MQTT connection is established, rather than waiting for ages if the MQTT server is unavailable.

Update:

I wrote a modification to take a callback function, and called it in an else clause added to that if statement, and discovered that the blocking delay is not this while loop. I think it's in the _client->connect at the start of the method.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.