[REBOL] Re: Concurrent access to data file

[CRS - Psy Sel/SPO, COUSSEMENT Christophe, CPN]

>   i solved this problem with poem access on my site by
> creating new read and write functions that "lock" the 
> file while it's being read from or written to. 
>   the lock is just a temporary file that is removed as
> soon as the read or write is finished. the lock exists
> only as long as it takes to grab the data out of the
> file or write to the file ... so the lock does not 
> exists the whole time the script is running, just for
> about a fraction of a second, if that.
>   read locks are time stamped so there may be multiples
> of them, this is because a read lock only prevents 
> writing, not reading. a write lock is just a single 
> file that prevents other processes from writing to or
> reading from the file.
> 
>   the read and write functions recheck for the lock
> file's existence about every 100th of a second. the 
> read function only checks for a write lock while the
> write function checks for a read or write lock.
> 
>   i'd share the functions with you, but i wrote them
> in perl. should be very easy to do in rebol.
        [Thanks Erin for answering.
        I think the solution you propose here is the one I presented when
initiating this thread.
        It's a -relative- safe one (see thread for discussion about it) but
will give poor performences when 40 to 80 PC's you want to dump their data
together ...
        Thanks anyway ;-)

        Best Regards,

        chr==
        ]  

>   cheerfulness,
> 
>                                       -----EAT
> 
> 
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