Re: How to clear pending events?

["Andrew E. Makeev" <andrew solvo ru>]

В Срд, 29/08/2007 в 14:33 +0100, jcupitt gmail com пишет:
> 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.
> 

Well, thanks for the suggestion. It could work if my application was on
development stage, but it is in production now :).

I found a solution - keep Glib::Dispatcher objects alive, until next
request to create new one.

Just having function like (g_)gtk_main_clear_events() or
(g_)gtk_main_ignore_events() would be more convinient than watching
signal objects life time and blocking list of signals you would to
ignore.

Regards,
-andrew