[Haskell-cafe]Re: Hugsvs GHC (again)was: Re: Somerandomnewbiequestions

Keean Schupke k.schupke at imperial.ac.uk
Thu Jan 20 09:55:54 EST 2005


Keith Wansbrough wrote:

>>read. I don't see the problem... (Okay, I can see that if select lies, 
>>and the
>>read takes a long time you might miss the next scheduling timeslot - but
>>as far as I am aware select doesn't lie, and read will return immediately
>>if select says there is data ready)...
>>    
>>
>
>select() _does_ lie for "ordinary files", e.g., disk files.  It
>assumes the data is immediately readable, even if it hasn't pulled it
>off disk yet.  If the "ordinary" file actually resides on an NFS
>volume, or CD, or something else slow, then you have a problem.
>
>--KW 8-)
>
>  
>
But the kernel does read-ahead so this data should just be a buffer copy.

    Keean.


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