Re: some ideas for multithreading support

[Sam S. <sd...@gn...>]

Hi,

> *  <Wbret-Plevy.Ubruyr@g-flfgrzf.pbz> [2017-12-20 14:40:46 +0000]:
>
>
> Regarding concurrent hash-tables, I'd relax the requirements about iteration:
>
> - Iteration must terminate.
> - The set of keys need not match the serializable database isolation level.
> - It's OK for some keys to be missing from the enumeration! That's the price
>   an application pays for going through a table without adequate outer locking.
> - No key shall be presented twice(?) (except if it's removed + re-added meanwhile)
> - Iteration must not crash.

I may be missing something, but it seems to me that the requirements are
contradictory:

If one thread keeps adding and removing a key, then the other thread may
iterate over the table forever, presenting the same key over and over
again.

However, this seems like a corner case.

-- 
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