From: peter@transvirtual.com
Date: Mon Jan 04 1999 - 18:48:15 EST
On Mon, 04 Jan 1999, Godmar Back wrote:
>Peter and I had discussed how to avoid polling in the awt, but this
>is the first time I look at his code. Judging from the comments in
>the code, there seem to be some problems with approach.
>I would strongly suspect that the problem comes from the fact that
>the transport routines in Xlib cannot deal with a non-blocking fd.
That's right. You have to make sure that blocking does only happens in
nextEvent(), e.g. because you have to give up the Toolkit lock (or you end up
in deadlocks). If the blocking is deterministic (e.g. with some round-trips),
that's Ok, but otherwise it is a nogo. But I think I figured out all
relevant Xlib calls, and haven't experienced any problems for quite a while
(even though this might vary between different Xlibs / servers). Xlib really
isn't multi-threaded at its heart, but I think we qualify for one of the first
really multi-threaded X-apps (w/o any polling). The impacts can be rather
dramatic, I once got a speed improvement for the CaffeineMark Dialog test
(which is rather strange because it doesn't reflect real AWT app structure) of
a factor of >20 compared to the JDK.
Edouard - thanks for the List / PopupWindow hints, will take that in, too. It's
getting high time for a new update.
-- Peter
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