Occasional segmentation fault when non-blocking function is interrupted by end of script

[mgeier]

This only happens if a script ends before playback is finished.

This isn't a real problem since you would use a blocking call or at least sd.wait() in a Python script.
But crashing the interpreter isn't really nice ...

This is an example script to reproduce the error:

import sounddevice as sd
import numpy as np

sd.play(np.zeros(100000))

Note that the crash doesn't happen every time, only occasionally.

[tgarc]

I was trying to look at this but I quickly realized that sounddevice isn't actually a compiled extension which makes it more difficult to debug C issues like this. Is it much more troublesome to make it into a compiled extension?

[mgeier]

I'm not sure if I understand ...

It would be reasonably simple to switch from CFFI's ABI mode to API mode, see http://cffi.readthedocs.io/en/latest/cdef.html.
This would change hardly anything in the implementation, most notably, the callback would still be implemented in Python.

If by "compiled extension" you mean manually writing C code using the Python C API, this would be an insane amount of work. Also, PyAudio already does that: https://people.csail.mit.edu/hubert/pyaudio/.
In this case, the callback would still be written in Python.

If you mean to keep CFFI (in API mode) but implement the callback in C, that's what I'm doing in https://github.com/mgeier/python-rtmixer/.

Finally, if you are talking about using the Python C API and implementing the callback in C, that's what pyo does: https://github.com/belangeo/pyo.

[tgarc]

Sorry about the vagueness, I actually just meant using CFFI in API mode. All this would do is produce some debuggable C code.

[mgeier]

OK. It should be straightforward, but I haven't actually tried it.

Do you want me to make a branch for API mode?

[tgarc]

Nah, I wouldn't put this at a high priority. I will experiment with it in the near future. I've done it for a previous project and I agree it *should* be straightforward.

…

On Mon, Feb 6, 2017 at 11:43 AM, Matthias Geier ***@***.***> wrote: OK. It should be straightforward, but I haven't actually tried it. Do you want me to make a branch for API mode? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#1 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAaVHGL9uARHrapPAYB6tAxeWTHk_hmlks5rZ1vPgaJpZM4FIMt0> .

[mgeier]

Fixed by #75.