Flic Hub firmware bug causes crash after sending 36 UDP packets.

peter.kueffner

I was developing a module on the Flic Hub using the Flic Hub SDK. The module sends out all button presses as UDP messages.

While working on the module, I noticed a strange bug, which I assume is a firmware issue - when sending the 36th UDP message, the module crashes with a

FATAL ERROR:
uncaught: 'cannot push beyond allocated stack'

I made a minimal module that will reproduce the bug consistently:

var dgram = require("dgram");

function SendJSON(data)
{
    try {
        udp = dgram.createSocket("udp4");
        udp.send(data, 32768, "127.0.0.1", function(err) {
                console.log("UDP sent. Return: " + err);
                udp.close();
            });
    } catch(e) {
        console.log("Error sending button state!");
    }
};

var i = 0;
var myInt = setInterval(function() {
        i ++;
        console.log("Sending packet " + i);
        SendJSON("" + i + "  ");
    }, 100);

Flic Hub SDK Console output:

Sending packet 1
UDP sent. Return: null
Sending packet 2
UDP sent. Return: null
Sending packet 3
UDP sent. Return: null
[...]
Sending packet 34
UDP sent. Return: null
Sending packet 35
UDP sent. Return: null
Sending packet 36
FATAL ERROR:
uncaught: 'cannot push beyond allocated stack'

I consider this a firmware bug because of the following reasons:

the "fatal error" is not catched by the try-catch block
the module is still considered "running" even after the crash (the SDK's "play" button stays in "can be stopped" state)

Is there any solution to this?

Emil

Thanks for the report. We will take a look. It seems like a bug in the hub sdk.