[Qt-interest] How to "snapshot" a QObject if it can't be copied?

[David Walthall]

Hostile Fork wrote:
> Hi all...
> 
> I have a QObject-derived class.  It has signals and slots that modify
> the object's data in a multithreaded environment.  (Yeah, yeah, who
> doesn't?)  :)
> 
> I'd like to be able to snapshot that object.  Because certain routines
> would be harmed by getting different answers from method calls on this
> QObject (if modifications happen on the other thread while they are
> working).  So routines have a QObject pointer, they call snapshot(),
> then they make all their method calls on the snapshot.  That way they
> don't see the modifications.

It sounds like what you actually need is a mutex.  If you need an object
to be unchanged during an operation, use a mutex to protect the object.
 In fact, if you can modify an object in one thread while accessing it
in another thread, you need a mutex.

David