Re: C++ Background Workers? - Mailing list pgsql-general

From Tom Lane
Subject Re: C++ Background Workers?
Date
Msg-id 2232.1404421250@sss.pgh.pa.us
Whole thread Raw
In response to C++ Background Workers?  (Quinlan Pfiffer <quinlan@aquameta.com>)
Responses Re: C++ Background Workers?  (Quinlan Pfiffer <quinlan@aquameta.com>)
List pgsql-general
Quinlan Pfiffer <quinlan@aquameta.com> writes:
> I'm trying to build a custom background worker for 9.3 in C++.
> Recompiling for -fPIC (as it says to) correctly builds the shared library,
> but then when I try to run Postgres with my .so file being loaded I get
> this:
> https://gist.github.com/qpfiffer/e59c9260b687a23e2743

Is it really necessary to make us go visit some random website for a
two-line error log?

For the archives (since I bet the above link will be 404 soon), the
failure looked like this:

2014-07-03 12:08:42 PDT FATAL:  could not load library "/usr/lib/postgresql/9.3/lib/pg_webrtc.so":
/usr/lib/postgresql/9.3/lib/pg_webrtc.so:undefined symbol: _Z30BackgroundWorkerUnblockSignalsv 

It looks to me like you need extern "C" { ... } around the
Postgres header files you're importing, so that the C++
compiler won't think it should mangle function names
declared therein.

            regards, tom lane


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