37 lines
1.4 KiB
ReStructuredText
37 lines
1.4 KiB
ReStructuredText
LAMMPS error handling in Python
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*******************************
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Compiling the shared library with :ref:`C++ exception support <exceptions>` provides a better error
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handling experience. Without exceptions the LAMMPS code will terminate the
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current Python process with an error message. C++ exceptions allow capturing
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them on the C++ side and rethrowing them on the Python side. This way
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LAMMPS errors can be handled through the Python exception handling mechanism.
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.. code-block:: Python
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from lammps import lammps, MPIAbortException
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lmp = lammps()
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try:
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# LAMMPS will normally terminate itself and the running process if an error
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# occurs. This would kill the Python interpreter. To avoid this, make sure to
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# compile with LAMMPS_EXCEPTIONS enabled. This ensures the library API calls
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# will not terminate the parent process. Instead, the library wrapper will
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# detect that an error has occured and throw a Python exception
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lmp.command('unknown')
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except MPIAbortException as ae:
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# Single MPI process got killed. This would normally be handled by an MPI abort
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pass
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except Exception as e:
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# All (MPI) processes have reached this error
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pass
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.. warning::
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Capturing a LAMMPS exception in Python can still mean that the
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current LAMMPS process is in an illegal state and must be terminated. It is
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advised to save your data and terminate the Python instance as quickly as
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possible.
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