Re: [Opensg-users] Ptrs, threading, and crashes

[Gerrit V. <vo...@ca...>]

Hi,

ok, after thinking a little and fixing my initial rather brain dead
tries ;), coming back to the initial problem set ;)

On Thu, 2009-03-26 at 17:21 -0500, Carsten Neumann wrote:
> 	Hi Gerrit, all,
> 
>
> Thinking about this some more Dirk and I found three problematic scenarios:
> 
> 1) the above situation with a beacon pointing "back" to an object that 
> already has a sub[Weak]Reference() running,

that should be fixed again.

> 2) an object that only has a weak pointer to it (e.g. it is held in a 
> cache).

not sure about that one, what was the problem with having only
a weak ptr to an object ? Except that you maybe could resurrect the
object through a very low level interface. But if we need to we should
be able to avoid this now.

> 3) two threads one giving up a reference to an object the other one 
> giving up a weak reference (this case currently still has a race I think).

yes it should have had. With the change to single ref count op
locations and the spinlock so that the refcount state can only
be seen in a consistent form I hope that should be gone.

kind regards,
  gerrit