Subj : [x86] simultaneous writes
To   : comp.programming.threads
From : Michael Pryhodko
Date : Wed Mar 30 2005 10:33 pm

Suppose that two threads running on two processors write at the SAME
time different 32bit values to the same 4-bytes aligned address on x86
platform (i.e. write is atomic). 'sfence' executed immediately after to
flush store buffers. (consider that before 'write' store buffers were
empty).

What will happen?

1. is it possible that after this different processors will see
different values in their caches? As far as I understand cache
coherency mechanism will prevent it, right?
2. how platform decides which value "win"?

Bye.
Sincerely yours, Michael.

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