Subj : an interesting threading-question
To   : comp.programming.threads
From : Oliver S.
Date : Wed Sep 14 2005 11:59 pm

I've got a question regarding threading with C/C++:
When I call a function which is out of scope for the compiler turn
(f.e. in another module without global optimization or a OS-function),
the compiler would have to flush all preceding writes and execute all
preceding reads to non-local variables (and local variables which have
been passed as references to "unknown" functions as well) to ensure
that these variables can be seen by the called function and that pre-
ceding reads wouldn't read data which could have been changed by the
called function - and this is usually done by a combined read/write
-barrier (and this is the same for following reads/writes and thus,
explicit barriers are often not necessary). But this is only necessary
for the executing thread to become self-consistent and not to become
consistent with other threads. So theroretically this barriers could
affect only the self-consitency and there could be further mechanisms
which would help to become globally consistent. So soes anyone know
an architecture which has two consistency-levels on account of this?

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