peter.kueffner peter.kueffner
3 May 2022, 14:53

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?