Hi,
This link will be of interest to those wanting easy concurrency. Works best for simple cases and can be used as a primitive in building up more complex concurrency controls. However, use with caution, especially when larger amounts of code are being executed that could conflict with other threads is involved. This applies even in the single native thread multiple Smalltalk "light weight green" processes environment of most Smalltalks.
http://onsmalltalk.com/programming/smalltalk/smalltalk-concurrency-playing-w...
Cheers,
Peter