Re: Event loop hangup when using TimeoutSource and IdleSource

[Jim Hodapp <james hodapp gmail com>]

Chris,

    I am sure that the library does not touch GTK+ functions. It's a  
C library and the only thing that touches the GUI is the GUI app  
itself and that's only via C++ and gtkmm. The library does no output  
other than to stderr. The library calls only get called one at a time.  
The only thing that is *parallel* is the loop in the library that is  
in a separate thread that calls select() to see if there's anything on  
the serial port to read, and checks the message queues to see if any  
commands need to go out to the device. I have the function that adds a  
new command to the message queue protected with a mutex just in case I  
ever have a GUI frontend that is multithreaded.

Thanks,

Jim


On Sep 24, 2009, at 4:54 PM, Chris Vine wrote:

> On Thu, 24 Sep 2009 16:43:21 -0400
> Jim Hodapp <james hodapp gmail com> wrote:
> > Chris,
> >
> >     I removed the inheritance statement from my Emsac class
> > definition and things seemed more stable. Things remained stable
> > until I moved the mouse over some widgets in the main window that
> > will accept focus and very shortly after that the application
> > segfaulted. The backtrace is as follows:
> > ...
> >
> > The GUI thread talks to the library thread directly through API
> > calls. I link the library into the GUI application and make direct
> > calls.
>
> Are you sure that these "direct calls" are thread safe?  Does the
> library call any GTK+ functions through its API and if so in what
> thread?  Your report about your mouse is symptomatic of what happens  
> if
> you try to address GTK+ from two different threads.
>
> Chris