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
8616	File-based sessions dropped with SESSION_SAVE_EVERY_REQUEST = True	warren@…	Jacob	"When using django.contrib.sessions.backends.file with SESSION_SAVE_EVERY_REQUEST = True, repeated requests for the same session that arrive very close together will cause corruption in the session file and result in a dropped session.  The recent changes in the session framework went a long ways in resolving this issue, but not quite far enough.

To resolve the problem, I tried using django.core.files.locks to lock the file when open for reading or writing.  However, this proved not sufficiently atomic.  The problem can be resolved using the atomic file locking flags when opening the session file for reading or writing.  Unfortunately, these are not available on all platforms.  The attached patch uses them if they are available.  This fixes the problem on platforms that support the atomic file locking flags."		closed	contrib.sessions	dev		fixed	session, file, race	wiser0	Accepted	1	0	1	0	0	0