Re: why is it called "asm-generic/atomic.h"?

From: Stefan Richter
Date: Thu Jun 07 2007 - 11:31:32 EST


Robert P. J. Day wrote:
> i'm just curious -- why does that particular header file have that
> name? its opening comment reads:
>
> * Allows to provide arch independent atomic definitions without the need to
> * edit all arch specific atomic.h files.
>
> but that's *not* what that header file does.

The file name is correct, and the comment is correct too. It indeed
_allows_ to define architecture-independent operations on atomic types,
and it currently does so for atomic_long_t. There is no need to do so
for atomic_t, because all architectures already had their own set of
atomic_t operations when asm-generic/atomic.h was added. (And I presume
they varied too much to justify an additional generic implementation
plus #ifndef HAVE_ARCH_SOMETHING games.)

PS: The atomic_long_t operations currently don't need to be protected
by #ifndef HAVE_ARCH_SOMETHING and won't need to be in foreseeable
future, therefore they don't have this protection.
--
Stefan Richter
-=====-=-=== -==- --===
http://arcgraph.de/sr/
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