David Greene wrote:
Moreover, how do I actually extract information from the state machine? Since fifo_scheduler<>::processor_handle is a weak_ptr<> I can't use it to query the state of the machine or extract any machine-specific information (such as elapsed time in the StopWatch example, if it were asynchronous).
The fact that it's a weak_ptr is an implementation detail. You don't need to know that as a user. Besides creation and destruction of FSMs, the fifo_scheduler interface only allows you to send events. So, the only means of data exchange is through callbacks and events (as outlined in the other post). It is not possible to access the state_machine subclass objects directly because that would mean accessing data shared between threads. This in turn would mean that every state_machine member function needs to be protected by mutexes, which is a recipe for disaster, in my experience. HTH & Regards, -- Andreas Huber When replying by private email, please remove the words spam and trap from the address shown in the header.