[RFC] reloader: wait for finished request

[blueyed]

The server should not be restarted while debugging (pdb.set_trace()).

Use case:

1. pdb.set_trace in the code
2. trigger web request
3. start debugging / messing around, maybe even use edit (via pdbpp) to edit files
4. save something being watched

This ends up in garbarge on the screen, and the server process/thread getting killed.

With this patch it waits for wsgi requests to finish before reloading.

Not much tested yet, and could certainly need a revisit/cleanup.

[davidism]

I'm hesitant to make these sorts of changes to the reload right now, as it's already a fairly complex system that I'm not having the easiest time maintaining. I'm worried about other behaviors as well, such as the reloader never triggering due to a large file upload/download, or a long running request. I'd say the much simpler answer for now is to disable the reloader if it's getting you during debugging.