This is a feature of the window manager you are using, in this case Compiz. Many window managers and implementations implement a protocol called _NET_WM_PING, which is a way for one X11 client to verify that another is handling and responding to X11 events.
Not all applications support this protocol, but most do, especially if they are using a fancy widget toolkit like GTK+ or Qt. An X11 client can give a hint to the window manager by listing _NET_WM_PING in a property of its window called WM_PROTOCOLS. Compiz will periodically send a ClientMessage to the target client using XSendEvent(), which includes a timestamp. The receiving client is supposed to respond immediately by sending the same message back to the sender. The idea is that each X11 client should have one thread that is processing events from the X server. If that thread is blocking because of deadlock, or some operation that is taking a long time, then it will not respond to these pings in a timely manner. If it is not processing these messages, it certainly isn't going to be able to process events from the user, so the window is considered non-responsive. The desaturation you see is a signal to you that the application isn't going to be responsive to any input. Firefox and Eclipse are both large, complicated applications that share a UI loop with lots of semi-trusted code. It's easy for one of your extensions, or JavaScript from a web page to block the UI thread. If you upgrade to a more recent version of Ubuntu, you'll be able to use FIrefox 3.6, which is *much* better at dealing with this. Or you could download Google Chrome :). -Kyle On Thu, Dec 2, 2010 at 8:04 AM, <[email protected]> wrote: >> -------- Original Message -------- >> Subject: [vox-tech] application greyed out >> From: Hai Yi <[email protected]> >> Date: Thu, December 02, 2010 4:24 am >> To: "lugod's technical discussion forum" <[email protected]> >> >> >> hello All: I am using ubuntu 9.10, in a quite frequent fashion, I >> noticed that the whole UI screen of some applications just grey out >> after working a while, as if they are under heavy resource consuming >> tasks. >> >> So far, this happened to Firefox > > This happens to me when using Firefox. It seems to be a reaction > to the website taking too long to respond. Most likely, it occurs > when the website starts sending the page but then stops in the > middle. But this is just a guess. > > <snip> > > _______________________________________________ > vox-tech mailing list > [email protected] > http://lists.lugod.org/mailman/listinfo/vox-tech > _______________________________________________ vox-tech mailing list [email protected] http://lists.lugod.org/mailman/listinfo/vox-tech
