Will ROS2 (rclpy, etc.) support PyPy which would enable better performance?
Originally posted by thinwybk on ROS Answers with karma: 468 on 2018-05-23
Post score: 1
1 Answer
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There's no plan to do so, no. But anyone from the community could try to get it working. We do, however, make heavy use of C extensions, so I don't know well those integrate into PyPy. Last time I looked at it, PyPy only supported FFI-like bindings. Our current implementation uses CPython directly from C code to create PyObjects and stuff like that.
Originally posted by William with karma: 17335 on 2018-05-23
This answer was ACCEPTED on the original site
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Original comments
Comment by thinwybk on 2018-05-23:
What's your estimated effort for rclpy only? :)
Comment by William on 2018-05-23:
I have no idea. Assuming you go with the CFFI route (reusing our C API), you'll still have to write a lot of conversion code in Python and deal with generate messages (not sure if the generated Python messages will work as-is). It might be a considerable effort, but I don't know for sure.
Comment by thinwybk on 2018-05-24:
W.r.t. parallel thread execution: PyPy suffers from GIL (like e.g. CPython does) and the GIL-free pypy-stm is highly experimental.
Comment by thinwybk on 2018-05-26:
Just for completion: Multiprocessing allows parallel execution until the number of processors is reached. Has in comparison to multithreading some advantages/disadvantages.
