Re: [(RT RFC) PATCH v2 5/9] adaptive real-time lock support

From: Pavel Machek
Date: Tue Feb 26 2008 - 13:06:27 EST


On Tue 2008-02-26 08:03:43, Gregory Haskins wrote:
> >>> On Mon, Feb 25, 2008 at 5:03 PM, in message
> <20080225220313.GG2659@xxxxxxxxxx>, Pavel Machek <pavel@xxxxxx> wrote:
>
> >> +static inline void
> >> +prepare_adaptive_wait(struct rt_mutex *lock, struct adaptive_waiter
> > *adaptive)
> > ...
> >> +#define prepare_adaptive_wait(lock, busy) {}
> >
> > This is evil. Use empty inline function instead (same for the other
> > function, there you can maybe get away with it).
> >
>
> I went to implement your suggested change and I remembered why I did it this way: I wanted a macro so that the "struct adaptive_waiter" local variable will fall away without an #ifdef in the main body of code. So I have left this logic alone for now.

Hmm, but inline function will allow dead code elimination, too, no?

Anyway non-evil way to do it with macro is

#define prepare_adaptive_wait(lock, busy) do {} while (0)

...that behaves properly in complex statements.
Pavel
--
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