Some issues with sslot 0.3 are fixed and I have added thread-safe signal-slots, based on the implementation suggested by Sean Kelly.

The thread-safe signals are the SignalMT and MapSignalMT classes.

There is one situation in multi-threaded code which I think is still unsafe and I have not been able to fix that: when during emission of a signal a delegate slot is invalidated from another thread due to garbage collection or manual deletion. This is ok from within a single thread though. I hope this is an acceptable situation for a thread-safe implementation.

Please note that this my first implementation of thread-safe signals, and although I have been very careful it may have some rough edges and it is certainly not optimal.

links:
http://lutger.ifastnet.com/
http://lutger.ifastnet.com/sslot/overview.html
(sorry for the ads, it seems my free hosting solution has changed its terms)