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?

johan 0

@Emil I'm having the same problem, with the original Hub on version 3.0.12. How do I get the fix? Workaround at the moment is to make the module crash every 10 seconds and enable restart on crash. If I would get over the limit before crashing myself, the bug is triggered and it will fail without restarting.

peter.kueffner

Thanks a lot! I will make sure to try the fix when the firmware update comes out.

Are there any plans to when this will happen?
And is there any way to get a notification for new firmware updates?

Emil

@peter-kueffner The issue has been fixed and the fix will be included in the next firmware update.

peter.kueffner

Hi @Emil, is there any progress on the issue?

Emil

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