Dear Reinhard Meyer,
In message <4d3c0271.4070...@emk-elektronik.de> you wrote:
>
> There were several suggestions about that in the past (including from me)
> that involve rework everywhere HZ related timeouts are used. I still
> prefer a method as follows (because it does not need repeated mul/div
> calculations
> nor necessarily 64 bit arithmetic):
>
> u32 timeout = timeout_init(100); /* 100ms timeout */
>
> do {...} while (!timed_out(timeout));
I dislike this approach. I immediately fear the same problem I just
saw (incorrectly) in Albert's proposal - timeout_init() seems to
store the timeouut information in some internal varoable, which is
then checked by timed_out() - this is bound to fail as soon as
somebody atttempts to nest timeouts.
Your implementation may be different, but you can bet sooner or later
comes up with such a bugy implementation.
And it is not needed.
PLease see my proposal: we do not needs several timer or timeout
related functions, all we need is a plain "get timer" function,
without any arguments. And the resulting code makes it obvious to the
reader that such loops can be nested as you like.
> time_out(x):
> return ((i32)(x - fast_tick)) < 0;
>
> If the tick were really high speed (and then 64 bits),
> fast_tick could be derived by shifting the tick some bits to the right.
I have no idea what "fast_tick" versus "tick" means here, nor why we
would need more than one tick.
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de
As a general rule, the freedom of any people can be judged by the
volume of their laughter.
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