I don't think I was specifically involved in AWT fixes for that issue, but the concerns that David raises are all valid
and Phil correctly points out that this is much worse in a network display environment...
...jim
On 4/4/17 3:53 PM, Philip Race wrote:
AWT used to have really bad at X11 remote display and
it was looked at a few times and I think it was improved
noticeably when we could get rid of "round trip" requests.
I think Jim had a hand in some of that work.
So I am sure a round trip - or similar - is bad for performance.
If you want to measure the effect of such change, remote display to
your desktop from a machine in a geographically distant site.
It is the latency that kills performance, not the bandwidth.
-phil.
On 4/4/17, 3:43 PM, David Hill wrote:
On 4/4/17, 1:27 PM, Semyon Sadetsky wrote:
Hello Kevin & David,
Please review the fix for jfx9:
bug: https://bugs.openjdk.java.net/browse/JDK-8176844
webrev: http://cr.openjdk.java.net/~ssadetsky/8176844/
--Semyon
Semyon,
I have been sitting here for a while thinking about adding
gdk_display_sync(gdk_display_get_default());
I can see why this might address many issues, as it flushes the pipeline and
waits for the X11 server to catch up.
That is balanced out by a historical distrust of using XSync in any situation
where the consequences.
Part of me thinks it is minimal overhead though, the other part does not like
stalling the asynchronous X11 design.
The other part of me would like to use this only for the window events that
need it, instead of all of them.
and I found this in hte GTK docs:
gdk_events_pending ()
Waits for a GraphicsExpose or NoExpose event from the X server. This is used in
the GtkText and GtkCList widgets in
GTK+ to make sure any GraphicsExpose events are handled before the widget is
scrolled.
so perhaps this should be used in some cases (like setVisible).
sigh.
Will try to make up my mind tomorrow.
Dave.
