id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
9722	Use pyinotify (where available) instead of polling filesystem every second to detect changes	Chris Lamb	Unai Zalakain	"This patch series adds support for pyinotify to replace the ""poll-every-one-second"" mechanism in django.utils.autoreload on systems where that library is available.

Inotify is an event-driven notifier for monitoring filesytems changes. Instead of dancing around the filesystem comparing modification times every second, we can simply register all the files we are interested in and let the thread block until one of them changes. When this happens, we reload the server as before.

This has the following advantages over the current polling system:

 * Scales far better to larger projects.
 * Response time to code changes is drastically reduced - the server restarts pretty much instantly instead of having to wait ~0.5 seconds for the reload.
 * More robust change detection - pretty much all forms of modification of the interested file are noticed (in particular, moving the file and editing the file without changing the mtime)
 * Saves battery usage - I have to use --noreload on my laptop (with encrypted filesystems) as it noticably reduces my battery life. Django is killing kittens.
 * Cleaner implementation - Polling is just dirty, and requires us to maintain a huge dict full of modification times.

Whilst inotify is Linux-specific, the patch gracefully degrades if a suitable version of pyinotify is not available. It does not add pyinotify as a dependency to Django.
"	New feature	closed	Core (Management commands)	dev	Release blocker	fixed		unai@…	Ready for checkin	1	0	0	0	0	0