christophfroehlich
commented
2 years ago I played a little bit with Multiprocessingand concurrent.futures.
I got to the point
TypeError: cannot pickle '_jpype._JPackage' object
which means that I cannot run more than one simulation with the same orh instance. There is a pickle support of jpype, but I've no glue how to start with it.. https://github.com/jpype-project/jpype/issues/533
Trying to create more than one instance of orhelper.OpenRocketInstance() gives
File "....\ortools\lib\site-packages\orhelper_orhelper.py", line 50, in enter jpype.startJVM(jvm_path, "-ea", f"-Djava.class.path={self.jar_path}") File "....\ortools\lib\site-packages\jpype_core.py", line 177, in startJVM raise OSError('JVM cannot be restarted')
It seems to be impossible to launch the JVM (i.e., orhelper.OpenRocketInstance()) more than once within the same python script: https://github.com/jpype-project/jpype/issues/959
@PatrickKa Any ideas how to overcome this?
Maybe we can duplicate the jar file and load two orhelper for different files. But for creating more than one OR-jar file we would have to adapt orhelper, because the jar file is hardcoded: https://github.com/SilentSys/orhelper/blob/bc240170b8fde9077c7e4ab6cd2aa01ace142a36/orhelper/_orhelper.py#L14
The dispersion analysis, basically a monte-carlo simulation, is predestinated for parallelization.
How could one implement this within this python/java framework? Maybe https://docs.python.org/3/library/multiprocessing.html would do the job.