Re: [Boost-users] [boost-users][signals2] thread-safe disconnection for intrusively ref-counted objects

Subject: Re: [Boost-users] [boost-users][signals2] thread-safe disconnection for intrusively ref-counted objects
From: Frank Mori Hess (frank.hess_at_[hidden])
Date: 2009-05-12 15:07:40

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On Tuesday 12 May 2009, Igor R wrote:
> // pseudo-code!
> class intrusively_refcounted : //...
> {
> private:
>   void listenToAsyncSubsystem()
>   {
>     // signals will come from another thread
>    
> asyncSubsystem_.someEvent.connect(slot_type(&intrusively_refcounted::handle
>r, this).track(???)); // can't use here shared_ptr/weak_ptr for tracking }
> };
>
> I could store a connection object, so that it would be
> destroyed/disconnected in ~intrusively_refcounted(), but I guess it's
> not thread-safe, just like the approach with "trackable".
>
> So what would be the correct approach?

Could you implement intrusively_refcounted with a pimpl owned by a shared_ptr?  
So a group of equivalent intrusively_refcounted objects might share a single 
dynamically allocated shared_ptr which the delete when the refcount hits 
zero, and it could also be used to obtain a weak_ptr for tracking.
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