Comment 125 for bug 226470

The conditions documented by "D. Hugh".indicate the potential problems of a multi-CPU system with software not designed for such. The problem is that when an async window/tab refresh comes in the second CPU may get it while the first CPU is dealing with the process of deleting and redrawing the first window.

You have to delete the async refresh operations before you attempt to redraw a tab or window.

The X server is taking things stuck into a queue and if you stick a "delete window" operation into the queue and then an async operation sticks a "do something with that window" into the queue it is not surprising that problems result.

The X (windows) server I believe is working ok. It is Firefox which is not recognizing that it is attempting operations on windows in the process of being deleted.

There should either be a block on operations on windows being deleted or there should be an elimination of refresh operations on windows being deleted.