Re: bdb db / cache locking problem (ITS#3201)

[jongchoi@OpenLDAP.org]

Hmm... but that does not explain the original ITS because only adds were
performed.
Then, does it mean that the entryinfo is not protected while entry itself is
protected by the transaction ?
- Jong-Hyuk

> OK... I've duplicated this problem by running test008 with cachesize set
> to 2 entries. modrdn crashes consistently in this case.
>
> The problem is that the cache only uses locking to determine whether an
> entry is idle or not, but locks only protect us from interference from
> other threads. In the case of modrdn, it is this operation itself,
> within a single thread, that is touching many entries and so churning
> the entry cache. Looks like we need to add a refcounter back to the
> EntryInfo. (slaps forehead...)