[erlang-questions] wxErlang

Bob Cowdery <>
Sat Jan 12 21:56:23 CET 2008

Hi Dan

I hope you can help on this one. I have a situation where erlang will
spontaneously exit. I thought this was probably one of my linked-in
drivers going barmy but I've tracked it down to something in wx.

The situation is this. I have several UI processes running, They share
nothing and don't need to interact directly as that's all handled by a
back-end FSM. I have therefore given them each their own environment and
do not pass the environment across. Two of these processes are graphical
in that they just draw stuff on the window. One of these draws a
real-time graph refreshed every 100ms, the other is a set of digits that
scroll and use mouse motion and wheel events. Both use wxBufferedDC to
avoid flicker.

It seems that there is some interaction between these two widgets. I can
see some of the drawing operations on one widget being reproduced on the
other. If I play with the scrolling digits I can get erlang to
spontaneously exit. I suspect this is a threading issue as I have seen
erratic drawing before when attacking the GUI from two different

Unfortunately I have so far failed to reproduce this in a simple example
but if you don't have any ideas I will keep trying.

Great toolkit by the way, keep up the good work.


More information about the erlang-questions mailing list