Hanging Sun application

[Charlie Martin]

I have a problem with a Sun window system application, under SunOS 3.5.
The problem is that an application which I have written hangs and responds
to no keyboard events about one time in seven when it is run.  It responds
correctly to mouse events, and can be terminated by using the frame menu.

The application has a ttysw subwindow and a simple graphics subwindow; it
can be thought of as a limited terminal emulator written to avoid the use
of tektool which isn't very satisfactory for our application.

Does anyone have any idea how (a) this can happen -- I especially dislike
the apparent randomness and intermittence of the problem -- or (b) any
hints how to debug the blooming thing?

Thanks for all assistance.

Charlie Martin (crm at cs.duke.edu,mcnc!duke!crm)