Bug 23531

Summary:	TpConnectionManager leaks async call if disposed before it becomes ready (or not)
Product:	Telepathy	Reporter:	Will Thompson <will>
Component:	tp-glib	Assignee:	Telepathy bugs list <telepathy-bugs>
Status:	RESOLVED MOVED	QA Contact:	Telepathy bugs list <telepathy-bugs>
Severity:	normal
Priority:	medium
Version:	unspecified
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:

Description Will Thompson 2009-08-26 10:06:51 UTC

As far as I can tell, waiting_for_ready only gets freed up in tp_connection_manager_ready_or_failed(). That function is called when the TpCM gets information from the CM or from a .manager file, or when the CM's name goes away. If TpCM is disposed while introspection is in progress (or before the idle in which the manager file is read fires), I don't think they'll get called.

(Also, the currently-running method call is not cancelled, so I think it'll probably crash too.)

This is not as simple as putting a call to tp_connection_manager_ready_or_failed() into _dispose(). On that path lies madness:

 * Application makes a TpCM, calls call_when_ready() on it;
 * User does something, the application decides it no longer cares about the TpCM, and unrefs it;
 * The application's callback fires;
 * If the application developer wasn't very careful to move its pointer to the TpCM out of the way before unreffing it, the callback will probably go wrong and crash.

(That said: if you have multiple different bits of your application setting up call_when_ready callbacks, it's already scary if one of them unref()s the TpCM because the callback might fire later. Argh.)

Comment 1 Simon McVittie 2013-07-22 17:33:51 UTC

Since some version older than 0.20, call_when_ready has been a wrapper around tp_proxy_prepare_async(), which keeps the proxy alive until it has become ready (or failed to do so).

> (Also, the currently-running method call is not cancelled, so I think it'll
> probably crash too.)

This still stands, but is mitigated by the fact that most applications will be preparing the proxy now, so it won't get disposed that soon.

Comment 2 GitLab Migration User 2019-12-03 19:23:21 UTC

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