[flext] GUI Seems to hang up (OSX Lion, PD-extended 0.42.5)

[Spencer Russell]

I'm developing an external based on Flext to interface with the
Snyderphonics Manta control surface using hidapi.

It seems to be working well, but in my help patch after a while it
seems that the GUI hangs, though the messages coming from the manta
are still being handled and I still hear the audio continue to respond
correctly.

I've seen both the main PD consol window stop responding, and also the
patch window, and sometimes both. It doesn't take more than a minute
or two of playing around to generate the bug

Here's the GDB output during the hang:
https://gist.github.com/1695888

It seems like the commands that are going to the GUI are getting
munged together? I don't know much about how the whole GUI
communication works, so I figured I'd post out to see if anyone can
help debug.

Is this an issue with my object, or with PD? Something with Flext? I
do have a separate thread running that polls the device and sends
messages out when new data is available, but my understanding is the
Flext queues those messages up and (hopefully) properly spits them out
to the main PD thread.

The source for my external is at: https://github.com/ssfrr/libmanta

Thanks for any help!

-spencer