Interrupting the kernel does not work on Windows

[amilsted]

I am running IJulia v1.4.1 on Julia v0.5.0 under Windows 10.

I am unable to interrupt the kernel during a computation with Julia running on Windows, despite being able to interrupt the same operations without issue with Julia running on Linux. This is not a new issue - I have been using IJulia for about a year (mostly with Julia v0.4.x) and have never so far found the kernel interrupt feature to work on Windows.

In summary: The "interrupt" option in the "Kernel" menu appears to do nothing except flash the message "Interrupting the kernel" when the kernel is running on Windows.

[amilsted]

Presumably related to quinnj/Sublime-IJulia#33.

[stevengj]

Jupyter is supposed to be sending a SIGINT to the kernel process. @minrk, does it do something different on Windows, since signals work differently there?

[minrk]

Yes, signals are weird on Windows, so we send a Windows Event here, created here. The event is passed as the JPY_INTERRUPT_EVENT environment variable (an integer). IPython's handling of this is here.

I have a vague recollection that this was because when the kernel is given a new process group, it can no longer be interrupted.

I opened jupyter/jupyter_client#244 to document this, and possibly revert to sending plain signals on Windows.

[jankatins]

This might be related: jupyter/jupyter_client#104

[filmor]

Since I had the same issue with my Erlang Jupyter kernel, I've added an interrupt_mode configuration option that allows you to receive a message instead of a SIGINT (jupyter/jupyter_client#294). I'll look into implementing this in IJulia.

[carstenbauer]

This would be a big improvement! Not being able to interrupt a calculation is super bad.... Thanks for working on it!

[carstenbauer]

@filmor Did you make any progress here?

[filmor]

I did (well, actually only after you pinged and I looked into it again ;)), it works for me and is pending review.