file locking...

[Nigel Rantor]

zugnush wrote:
> You could do something like this so that  every process will know if
> the file "belongs" to it without prior coordination, it  means a lot
> of redundant hashing though.
> 
> In [36]: import md5
> 
> In [37]: pool = 11
> 
> In [38]: process = 5
> 
> In [39]: [f for f in glob.glob('*') if int(md5.md5(f).hexdigest(),16)
> % pool == process ]
> Out[39]:

You're also relying on the hashing being perfectly distributed, 
otherwise some processes aren't going to be performing useful work even 
though there is useful work to perform.

In other words, why would you rely on a scheme that limits some 
processes to certain parts of the data? If we're already talking about 
trying to get away without some global lock for synchronisation this 
seems to go against the original intent of the problem...

   n