turning off tbb dependency without recompiling deal.II ?

[Mathieu]

Hello everyone,

my question is a follow-up on this question that I created some weeks ago.

In a nutshell, I want to link deal.II against matlab, which results in a segmentation fault.

#include <deal.II/grid/grid_generator.h>

#include "MatlabEngine.hpp"

#include "MatlabDataArray.hpp"

//step-1.cc

int main()

{

matlab::engine::startMATLAB(); //provided by  matlab

dealii::Triangulation<2> triangulation;

}

The call to startMATLAB() results in a segfault, however,

there is no segfault if I comment the triangulation object.

Matthias Maier pointed me in the right direction by considering

ldd ./step-1

which lists, amongst many others, a symbol to the deal.II library and

libtbb.so.2 (thread building blocks)

I could figure out that matlab links against their own shipped version of tbb,

which probably results in the "symbol clash" that Matthias also mentioned.

I compiled deal.II with tbb enabled.

My question is if there is a way to "turn off" the tbb dependency (using a cmake variable) locally such that

ldd ./step-1

does not contain libtbb.so.2 anymore.

I know that one can do for instance

export DEAL_II_NUM_THREADS=1,

but that has no effect on the ldd call.

Thank you,

Math

[Wolfgang Bangerth]

On 7/12/23 11:56, Mathieu wrote:
>
> I compiled deal.II with tbb enabled.

> My *question* is if there is a way to "turn off" the tbb dependency (using a

> cmake variable) locally such that
> ldd ./step-1

> does not contain *libtbb.so.2* anymore.

> I know that one can do for instance
> export DEAL_II_NUM_THREADS=1,
> but that has no effect on the ldd call.

Right. You need to recompile and reinstall deal.II if you change this
configuration parameter.

Best
W.

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Wolfgang Bangerth email: bang...@colostate.edu
www: http://www.math.colostate.edu/~bangerth/