ITAGAKI Takahiro wrote: > Tom Lane <[EMAIL PROTECTED]> wrote: > > > > I have a question about SHM_QUEUE. Why do we need this component? > > It's a hangover from Berkeley days that no one has felt a need to remove > > yet. > > > > > Then, can we replace SHM_QUEUE by a pointer-based double-linked list? > > What exactly will you gain by it? I'm not inclined to fool with that > > code for trivial reasons ... > > Hmmm, my next question is whether we should use SHM_QUEUE or not in > new modules. The point deluded me when I wrote DSM and I wondered > the autovacuum-multiworkers patch uses SHM_QUEUE.
Good question. I used SHM_QUEUE because I just believed the comments that said that ShmemBase would be different on each process, and so using plain pointers would not work. I admit I didn't even try. So if the list can be implemented in a different way, I have no problem with changing that code -- but then, if there's no practical problem with it I feel uninclined to continue messing with the patch until it's committed. -- Alvaro Herrera http://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
