Abstract
A synchronization mechanism using asynchronous activation and cancellation is considered. A process can receive asynchronous signals. The signals can either suspend the current activity causing the process to execute a handling procedure, or they can cancel the current computation. The Petri Net formalism is employed to describe the behavior of the system. An extension to Color Petri Nets, Region Based PN, is proposed to model actions affecting a set of places while the exact marking is neither known nor important.