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Subject: Re: [PATCH 1/5] lib: introduce call_once()
From: Joe Perches <joe@perches.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>, nickpiggin@yahoo.com.au,
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Date: Tue, 11 Mar 2008 11:56:55 -0700
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On Tue, 2008-03-11 at 10:35 -0700, Andrew Morton wrote:
> #define ONCE()                                              \
>     ({                                              \
>             static long flag;                       \
>                                                     \
>             return !test_and_set_bit(0, flag);      \
>     })

test_and_set_bit takes an address

Perhaps:

#define DO_ONCE(x) \
	({ static long flag; if (test_and_set_bit(0, &flag)) x; 1; })

DO_ONCE(foo);