Re: [RFC, 2.6] a simple FIFO implementation

[Bill Davidsen]

Stelian Pop wrote:
> Hi all,
>
> Is there a reason there is no API implementing a simple in-kernel
> FIFO ? A linked list is a bit overkill...
>
> Besides my sonypi and meye drivers which could use this, there are
> quite a few other drivers which re-implement the circular buffer
> over and over again...
>
> An initial implementation follows below. Comments ?

Many.

- you don't need both size and len, just the length
- you don't need a count of what's in the fifo, calc from tail-head
- you don't need remaining, when the tail reaches the head
  you're out of data.
- you want to do at most two memcpy operations, the loop is just
  unproductive overhead.
- if the fifo goes empty set the head and tail back to zero so you don't
  wrap (assumes doing just two memcpy ops) when you don't need to

--
   -bill davidsen (davidsen@xxxxxxx)
"The secret to procrastination is to put things off until the
 last possible moment - but no longer"  -me
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