Re: How to clear pending events?

[jcupitt gmail com]

On 8/27/07, Andrew E. Makeev <andrew solvo ru> wrote:
> When GUI-objects are destroyed, Glib::Dispatcher notifiers are destroyed
> as well, but it happens before MAIN-LOOP actually reads all events those
> were stored by notifiers. So, application crashes, when trying to access
> data from Glib::DispatchNotifier structure.

I have a similar thing in my (plain C) application. A set of
background threads calculate image tiles for display. If an image
display window is destroyed, I need to not respond to any more tile
repaints from the background.

My solution was simply to keep a list of valid tile generators and for
my GUI thread to check each incoming tile's source. If it sees an
event coming from a dead tile generator, it discards it.

This is potentially crashable if an address is reused: a tile
generator with a pending tile might be destroyed and a new one then
made which happened to be at the same point in memory as the old one.
This hasn't been a problem for me, since tile generators are only made
much later, after the queue will have cleared.

I guess if this is a problem you'd need the data generators to track
their pending requests and cancel them all on destroy. This should be
easy if you use g_idle_add() rather than Glib::Dispatcher.

(I hope I've understood your problem)

John