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
20613	LocMem cache may cause deadlocks	Rafal Stozek	nobody	"LocMem cache uses locks to synchronize access to the cache dict.

The problem is that pickle dumps/loads is executed inside code blocks which acquired a reader/writer lock. Pickle dumps/loads can execute parts of user's code to accomplish it's task. The problem starts when user's code tries to retrieve something from the cache.

In that situation for example set() acquires a lock, calls pickle.dumps() which calls user's code, which calls get(), which tries to acquire a lock - causing a deadlock. Very rare situation but it does happen."	Bug	closed	Core (Cache system)	dev	Normal	fixed			Accepted	1	0	0	0	1	0