[Python-Dev] Weird use of hash() -- will this work?

Christian Tismer tismer@tismer.com
Thu, 18 Jan 2001 22:56:08 +0100


"Eric S. Raymond" wrote:
> 
> So I'm writing a module to that needs to generate unique cookies.  The
> module will run inside one of two environments: (1) a trivial test wrapper,
> not threaded, and (2) a lomg-running multithreaded server.

What do you mean by "unique"? Unique regarding your long-running server?

If so, then I wonder why one should do
> 
> So, how about `time.time()` + hex(hash([]))?
>
instead of using a single, simple counter for all sessions?

> It looks to me like this will remain unique forever, because another thread
> would have to create an object at the same memory address during the same
> millisecond to collide.
> 
> Furthermore, it looks to me like this hack might be portable to any OS
> with a clock tick shorter than its timeslice.
> 
> Comments?

If I'm not overlooking something fundamental, the counter approach
seems to be simpler and most portable. :-)

but-sometimes-my-brain-malfunctions-badly-ly y'rs  - chris

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