From the X11 protocol spec:
"If background None is specified, the window has no defined background."
This means that toolkits and apps cannot rely on the "transparent" nature
of the current implementation! At some point before the next release,
XACE will switch back to a solid background as the default.
Subject: [PATCH] fix some performance gaps in Xace
The XaceHook function is used in several hotpaths.
The problem with it (performance wise) is twofold:
* The XaceHook function has a big switch() statement for the hook number in it
* The XaceHook function uses varargs to reassemble the final dispatch arguments again
Both are expensive operations... for something that is known at compile time
This patch turns the hotpath XaceHook call into a direct call to avoid
the switch and varargs; this gives me over 10% performance gain
on the x11perf benchmark.
delivery of events to windows and clients.
This is tentative. It's likely that an additional last-resort hook will
be necessary for code that calls TryClientEvents or WriteEventsToClient
directly. It's also possible that new xace machinery will be necessary
to classify events and pull useful resource ID's out of them.
The failure case also needs some thinking through. Should event delivery
"succeed" or should it report undeliverable?
Finally, XKB appears to call WriteToClient to pass events. Sigh.
arbitrary X status codes instead of just TRUE/FALSE.
The dix layer in most cases still does not propagate the return value of
XACE hooks back to the client, however. There is more error propagation
work to do.
