3.0.2: rlm_sql_null duplicating its statements

[Phil Mayers]

On 07/04/14 12:33, Arran Cudbard-Bell wrote:

> flock is sometimes just a wrapper around fcntl so may be just as broken,
> at least by moving to something we know is broken in terms of reflecting
> lock states internally, it means that we'll account for it in the code

True; it was working on native-flock-supporting systems accidentally in 
the old case, I bet.

Worth noting that flock() locks are inherited across fork/exec too 
(including exclusive locks). Which is nice...

> Anyway, I've just added a mutex around the writes for now.

I'm not sure that logic is right; doesn't the lock free (implicit in 
close()) need to be inside the mutex too?

>
> I spent a few days investigating locking schemes on *NIX a while back and ,
> came to the conclusion the only sane way of implementing a sane file locking
> scheme is to have a structure in the server core which holds all the currently
> open file handles, and their lock states.

Yes, it's a shame the APIs are so terrible.