RFC: KUSER_SHARED_DATA update patch to fix bug 29168
dragon at dancingdragon.be
Wed Mar 21 12:50:15 CDT 2012
> - The shared data structure should be modified with atomic
> accesses only. (Or use a criticalsection if possible.)
According the this website, Windows updates the times too frequently to
use a critical section:
The values are written in the order High2, Low, High1. Applications
read them in the reverse order; as long as the two High values are the
same, the composite value is considered correct. This is a fairly
common algorithm for detecting clock tick without atomic operations or
I could certainly use atomic operations for each of the 32-bit word
writes. But since Windows apps expect the word write order, I don't
think it's necessary or advisable to do 64-bit atomic ops.
> However, I do not know if we can have additional threads at all in a
> Win32 process without confusing the win32 processes, or if this needs
> to be solved differently (APC?).
A previous version of my patch used NtTimer/APC:
The APC code is commented out but still present in that version of the
It did not work, by which I mean SW:TOR did not successfully login. It
was clearly the best solution, so I'd be happy to return to it if we can
make the callback times more precise.
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