PEP 669: Low Impact Monitoring for CPython

[nedbat (Ned Batchelder)]

I’m still concerned that this point hasn’t been addressed:

@nedbat

All branches from that point. I can see the advantage of tracking each direction independently, but it would be a special case and would impact performance and memory consumption.

You’ve placed great emphasis on the idea of disabling a callback after it has fired. In order to measure branch coverage, I need to know all of the branches that have been taken. If I disable the branch event once I’ve received it, and that disables all branches from that point, then I don’t have the information I need. That’s why I said it would be useless to disable the branch event if it didn’t take the destination into account.

As Petr says, a PEP doesn’t need to be a complete design document. But where it does include specific details, they should be the right details.

Disabling a branch event after its first firing will make it useless. If I only get low impact monitoring by disabling the event, then I won’t have low-impact branch coverage. Is this OK?

Maybe I’m misunderstanding the centrality of this idea.