From: Jim Starkey
Date: January 29 2009 7:51pm
Subject: Re: Another Idea for Transaction Lifetime Control
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Jim Starkey wrote:
> Here's another idea.  Define an "in-use" flag in the transaction 
> object.  Before a scavenge, clear the in-use flag for transactions.  
> During scavenge, set the flag on every transaction referenced.  At the 
> end of scavenge, purge all transaction that are a) committed and b) 
> not marked as in-use.
>
> Since the flag is used exclusively by the scavenge thread, no locking 
> is required.
>
Sigh.  This suffers from the same problem as most of the other 
proposals, which is no guarantee that another thread doesn't have a 
stale pointer to the transaction.  Oh, well.

Cycle locks, anyone...

-- 
Jim Starkey
President, NimbusDB, Inc.
978 526-1376