Re: [BUGS] Patch to allow C extension modules to initialize/finish

Tom Lane wrote:

>"Ralf S. Engelschall" <rse@engelschall.com> writes:
>  
>
>>Hence I propose the patch below (applies to PostgreSQL 8.1.4) which
>>mimics the dlopen(3) and dlclose(3) behaviour of some Unix platforms
>>and resolves and calls _PG_init and _PG_fini functions of an extension
>>module right after/before the pg_dlopen/pg_dlclose calls in the FMGR.
>>    
>>
>
>This seems like a reasonably good idea, and we have got uses for at
>least the "init" case in most or all of our PLs.  It's nominally too
>late for 8.2 feature freeze, but I said just a couple days ago that
>we shouldn't take a very hard line on that.  Does anyone object to
>considering this for 8.2?
>  
>

I don't. We've been porous in the past and I think we should be prepared 
to be a bit lenient again, especially since this release is not hugely 
feature rich.

>One question I have is whether it really works as expected in all cases.
>In particular what if the library is "preloaded" into the postmaster?
>Both plpgsql and plperl seem to think they might need to make a
>distinction between things to do at library load time and things to do
>per-backend ... and yet, neither of them *actually* have anything they
>need to do per-backend.
>  
>


I have longterm plans for plperl concerning preloading perl modules, 
which might involve the preloaded lib. At the moment it's just a thought 
in my head, though.

>Also, what about Windows?  I assume that DSOs don't remain attached
>across the pseudo-fork/exec, will that mess anything up?
>
>
>  
>

Good question.

cheers

andrew