Matlab Crash: solver.get_parallel()

[stingjp]

Was trying to play around with parallelization. Set up a full muscle-driven, 3D tracking simulation. After getting the solver object, tried to call solver.get_parallel(), and it crashes MATLAB. Attached the crash log. solver.get_parallel_crashReport.txt

[stingjp]

Just tried to replicate, but used the solver.set_parallel(int) call first, and it didn't crash.

[nickbianco]

solver.get_parallel() crashes because the parallel property is optional, so it doesn't have a value by default. Makes sense that it doesn't crash after you set it.

There's some comments about why it is optional in the MocoCasADiSolver documentation.

[nickbianco]

It's not great that a crash occurs when the value is not set, but this property needs to stay optional so that the parallel setting logic remains intact.

Perhaps we add a warning in the MocoCasADiSolver docs that this property is optional and will crash if accessed before setting.

[aymanhab]

@nickbianco What is the meaning of the value passed in to set_parallel()? I'd assume some default of 0 or 1 would mean no parallelization without additional work but I don't know enough about how the solvers internals work.

[nickbianco]

The settings are described here: https://github.com/opensim-org/opensim-core/blob/6953a250f6dd6ffab2ebefdab03575973cfd80a3/OpenSim/Moco/MocoCasADiSolver/MocoCasADiSolver.h#L145

[jenhicks]

Please re-open if this is still causing issues.