Re: [Boost-users] [signals] Automatic connection management and MT

From: Gottlob Frege (gottlobfrege_at_[hidden])
Date: 2007-02-01 16:47:45

On 1/30/07, Timmo Stange <ts_at_[hidden]> wrote:
> I'm working on a preliminary solution for an interface-compatible
> but thread-safe implementation of Signals for my project so that I
> will be able to switch to Boost.Signals should Doug Gregor find
> the time to add thread-safety there.
>
> While deciding what parts to include and which to leave out, I
> noticed that the automatic connection management is probably not
> usable in a multi-threaded context in the current form. Using a
> base class destructor (signals::trackable) to monitor an observer's
> lifetime is bound to result in race condition trouble with the order
> of destruction in a class hierarchy.
>
> Has that been discussed somewhere and are there any proposed
> solutions/alternatives?
>

What if the signal held a weak_ptr to the slot-object?  Before
calling, it turns it into a shared_ptr, and voila, you won't get
deleted during the call?

Tony