> "Merlin Moncure" <[EMAIL PROTECTED]> writes: > > ... is there any merit to promoting the user lock wrappers out of > contrib > > Dunno. Yours is the first message I can recall in quite a long time > indicating that anyone was using userlocks. I thought the code was kind > of dying on the vine. Of course it's hard to tell whether that's not > just *because* it's in contrib and not mainstream. But personally I'd > like to see some more evidence of use before we promote it. (And yeah, > the API could probably use some cleanup first.)
Well, what's interesting about user locks is that all the real substantive stuff is already built into the lock manager. The userlock contrib module, depending on how you count it, consists of about 10 lines of actual code and only (minimally) exposes the lock manager. It's like some GPL code has parked itself on top of an existing server feature (and the copyright on the code in this module is dubious anyways, it being defined strictly by function). Plus, there are some important missing parts lock being able to resolve a locktag back to a pid and being able to query a lock without acquiring it. Anyways, there is a reasonable argument to be made for keeping user locks a loadable module because of the potential for misuse...it's just too easy to bring down a server with them in place. A remedy might involve some combination of the following: 1. rename max_locks_per_transaction to something more reasonable...this leads one to believe persistent locks are not managed here (but they are). 2. consider bumping out of memory condition in lock table to 'fatal' to better guard against a process in runaway lock acquirement...at least there is a chance for recovery now. 3. enforce a limit to max#locks for each process that is less than the total maximum size (for example, no single process can acquire more than half of the entire lock table). IMO, with some safety and usabilty aspects rolled in, documentation changes, and re-packaging, plus throw out the gpl stuff, this makes a reasonable (if somewhat esoteric) bullet point feature for 8.1. Merlin ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
