Re: [Factor-talk] context switch benchmarking

[Slava P. <sl...@fa...>]

On 16-Apr-07, at 6:26 PM, Csaba Henk wrote:

> Hi!Based on the sample code in the concurrency docs, I put together  
> this:
>
> !!!!!!!!!!!!!!!!! gentest.factor
> USING: kernel arrays quotations match concurrency math ;
> IN: gentest
>
> : decr-server
>     receive {
>         {
>             { ?from ?tag _ }
>             [ 1- dup ?tag swap 2array ?from send decr-server ]
>         }
>     } match-cond ;

Try putting the recursive call to decr-server after the match-cond.

> Why does that happen, given that Factor features TCO?

Because the recursive call is not a tail call; match-cond is not  
calling the quotation in tail position.

The following is a tail call:

: foo ... foo ;

So is this:

: foo ... [ ... foo ] [ ... ] if ;

Because 'if' calls the quotation in tail position.

Slava