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Matlab SIL Interface Issues
Dear QBlade Team,
I’m trying to use QBlade’s SIL Interface from Ubuntu 20.04 with Python 3.8 and Matlab 21b, 23a, 24a.
Using the sample scripts from the documentation works for Python without any issues. But running the sample scripts for Matlab results for all versions mentioned in Segmentation Faults during the call to createInstance. I attached the output in the txt file, the OpenCL warning also appears for the Python interface, so I don’t think that’s an issue.
Has anybody experienced similar issues? Or does anybody know what I might be missing?
Best regards,
Aaron
Hi Aaron,
I think you forgot to attach the output you mentioned.
Anyways, in the sample script createInstance() is the first time that a function from the library is called. If that already fails I would assume that the QBlade library isnt found?
I just tested on windows and running the script worked immediately (I changed the matlab workDir to the folder containing the script).
Unfortunately I dont have a Linux system running matlab, so I cannot test there…
BR,
David
Hi David,
thank you for your quick response. Now I attached the segmentation fault.
And I also ran the sampleScript.m (from the documentation) but commented out line 32 with ‘QBLADE.createInstance(1,32);‘ and then the script runs through with this output:
”’
Using DLL file: ../libQBladeCE_2.0.9.3.so
Library loaded and path set successfully.
Simulation failed at timestep 1. Exiting loop.
Library unloaded successfully.
”’
While this is not the final working version, this seems to confirm to me that function calls to the dynamically linked library are working but specifically `createInstance()` causes the issue.
Anyway, I’ll continue to try different solutions.
Best regards,
Aaron
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Hi Aaron,
the error dump reveals whats happening:
[ 0] 0x00007fac5f12ce96 /home/matlabuser/Documents/R2023a/bin/glnxa64/matlab_startup_plugins/foundation/platform/pf_matlab_integ/../../../../../../bin/glnxa64/libQt5Network.so.5+00302742
[ 1] 0x00007fac5f131cbc /home/matlabuser/Documents/R2023a/bin/glnxa64/matlab_startup_plugins/foundation/platform/pf_matlab_integ/../../../../../../bin/glnxa64/libQt5Network.so.5+00322748
[ 2] 0x00007fac5f12e40a /home/matlabuser/Documents/R2023a/bin/glnxa64/matlab_startup_plugins/foundation/platform/pf_matlab_integ/../../../../../../bin/glnxa64/libQt5Network.so.5+00308234 _ZN21QNetworkAccessManagerD1Ev+00000188
[ 3] 0x00007fac503f22ad /home/matlabuser/Desktop/qblade/QBladeCE_2.0.9.3/SIL_Interface/../libQBladeCE_2.0.9.3.so+02626221 _Z9getGADatav+00001117
QBlade crashes when trying to call the getGAData() function. The reason for this crash is a Qt shared library conflict.
On Linux, MATLAB brings its own Qt 5 libraries into the process (different from the version QBlade uses). When QBlade’s shared library is loaded, Qt symbols from MATLAB and from QBlade’s build get mixed – in this case, specifically from libQt5Network.so.5.
You could try setting the environment variable LD_LIBRARY_PATH to point to QBlades Libraries folder before loading the library in MATLAB (even directly in the matlab script).
Also make sure that the required Qt libraries from your system /lib directory are copied into QBlades Libraries folder, so they are found first when the shared library is loaded. This may help to prevent the Qt “cross-talk”.
Unfortunately, I can’t test this myself since I don’t have a Linux system running MATLAB.
Best regards,
David
