XDamage on pixmaps and XFlush/XSync

[Tamas K Papp]

Hi,

I am using cairo on a pixmap buffer, which I use to redraw the content
of the X11 window when needed -- if X asks for it, or if the pixmap
changes.  As suggested on the cairo list, I am using the Xdamage
extension for the latter.

My problem is that XDamage events are received by the window only when
it gets other events.  It turns out that calling XSync or XFlush after
drawing solves this, and my impression is that the XDamage extension
just puts the events into the output queue when the pixmap changes but
doesn't flush them.

Questions:

1. is this correct?

2. what can I do about it?  Is there any way to make XDamage flush
those events so I don't have to call XSync manually each time I draw
on the pixmap?

Thanks,

Tamas