Re: [GENERAL] Querying libpq compile time options

spaminos-sql(at)yahoo(dot)com wrote:
> From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
> > spaminos-sql(at)yahoo(dot)com wrote:
> > > Hi all
> > >
> > > I am writing an app that uses libpq, but because it is threaded I want to make sure that the dynamic
> > > library being used has been compiled with the right option.
> > > How do I do this?
> > >
> > > Is there a call such as "bool PQisThreadSafe()" that I can call?
>
> > Is this like detecting of libpq is SSL-enabled? I see PQgetssl(). Do
> > we need to add a libpq function to return true/false for threading?
> > Slony requires a threaded libpq, so it could do the test to prevent
> > wrong configurations. It would be nice to enabled threading by default,
> > but it is like SSL in that not all operating systems support it.
>
> Yes, this is exactly the issue I have: I want to enforce at runtime that the library being
> used is correct.
> btw, I noticed that for some reason the prebuild linux rpms for Fedora Core 3 are compiled
> without pthread support (and that's how I found out that I had to check the library on startup as I was getting strange lockups).
> I think the simplest is to add a new call just like the one you described for testing for ssl and tell people
> to call this function if they need the library to be thread safe.

Having heard no demand for libpq checking beyond threading, I have
implemented PQisthreadsafe(). I used PQisnonblocking() as an example.

One major argument for having a separate function, aside from lack of
demand for more, is that we are probably nearing the day when a theaded
libpq will be created by default on platforms that support it, and in
that case, there might not be a configure flag to check.

--
Bruce Momjian http://candle.pha.pa.us
EnterpriseDB http://www.enterprisedb.com

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