I took a look at the document. Basically you want to have two
different versions of the Arrow shared library loaded into the same
process, with some code linked to one library and some code linked to
another. This is very similar to the problem that Boost addresses with
the `bcp --namespace=$MY_PRIVATE_BOOST_NAMESPACE ...` operation.
To obtain strict symbol isolation you have to change the "arrow::"
namespace in the C++ libraries you are shipping in your application.
AFAIK, this is a bit of a nuisance to do. One way to achieve it is to
replace every use of
namespace arrow {
...
}
with
BEGIN_ARROW_NS
...
END_ARROW_NS
or similar. Then you would do something like `cmake
-DARROW_NAMESPACE=mwarrow ...` when configuring your build.
This change could certainly be implemented in the Arrow library, which
is a one-time mechanical operation but will create some ongoing
non-intuitiveness anytime new files are created. All headers must also
therefore depend on a central `arrow/config.h` which contains the
needed namespace macros.
On Fri, Mar 5, 2021 at 9:19 AM Antoine Pitrou <anto...@python.org> wrote:
>
>
> Hi Tashin,
>
> Sorry for the lack of response. Unfortunatly I feel a bit out of my
> depth on linker issues. I hope someone else can give advice.
>
> Regards
>
> Antoine.
>
>
> Le 05/03/2021 à 16:09, Tahsin Hassan a écrit :
> > Hi,
> >
> > I was wondering whether folks had a chance to look over the material and
> > had any pointers for the proposed approach.
> > If I should post in some other format or clarify something, please let me
> > know.
> > In the meantime, I will try out the steps we propose.
> >
> > Regards,
> > Tahsin
> >
> >
> > From: Tahsin Hassan <thas...@mathworks.com>
> > Date: Thursday, February 25, 2021 at 11:43 AM
> > To: dev@arrow.apache.org <dev@arrow.apache.org>
> > Subject: Re: [C++] libarrow isolation
> > Hi Antoine,
> >
> > I struggled a bit to put all my thoughts in an email format, that will be
> > easily consumable.
> > So, I wrote up a github markdown to add some more detail to the issue, we
> > are facing.
> >
> > Could you take a look, and let us know your thoughts?
> > https://github.com/mathworks/matlab-arrow-support-files/blob/main/libarrowclash.md
> >
> > Regards,
> > Tahsin
> >
> > From: Antoine Pitrou <anto...@python.org>
> > Date: Tuesday, February 23, 2021 at 1:21 PM
> > To: dev@arrow.apache.org <dev@arrow.apache.org>
> > Subject: Re: [C++] libarrow isolation
> >
> > Hi Tahsin,
> >
> > I see. So the error happens when loading PyArrow into MATLAB, I
> > suppose? What kind of error do you get?
> >
> > Regards
> >
> > Antoine.
> >
> >
> > Le 23/02/2021 à 18:12, Tahsin Hassan a écrit :
> >> Hi Antoine,
> >>
> >> MATLAB is using RTLD_GLOBAL. Hope that helps in clarifying the workflow.
> >>
> >> Regrards,
> >> Tahsin
> >>
> >> ________________________________
> >> From: Antoine Pitrou <anto...@python.org>
> >> Sent: Monday, February 22, 2021 9:41 AM
> >> To: dev@arrow.apache.org <dev@arrow.apache.org>
> >> Subject: Re: [C++] libarrow isolation
> >>
> >>
> >> Le 22/02/2021 à 15:29, Tahsin Hassan a écrit :
> >>> Hi all,
> >>>
> >>> MATLAB uses the Arrow C++ libraries (i.e. libarrow.so) to read and write
> >>> Parquet files
> >>> (https://www.mathworks.com/help/matlab/ref/parquetread.html) While
> >>> exploring ways to integrate more tightly with Arrow, we've run into a
> >>> symbol/library naming clash issue.
> >>>
> >>> When running pyarrow within the MATLAB process
> >>> (https://www.mathworks.com/help/matlab/call-python-libraries.html?s_tid=CRUX_lftnav
> >>> ), the libarrow.so loaded by pyarrow clashes with the libarrow.so
> >>> shipping with MATLAB.
> >>
> >> For the record, Python loads extension modules (such as PyArrow) with
> >> RTLD_LOCAL. I assume MATLAB doesn't?
> >>
> >> Regards
> >>
> >> Antoine.
> >>
> >>
> >
