Java

Hierarchical State Machines

A Java implementation of the kind of hierarchical state machine described in the book Practical Statecharts in C/C++, Quantum Programming for Embedded Systems, by Miro Samek, Ph.D.

That book has box-outs detailing the tiny overhead of it's mechanisms in terms of assembly instruction counts. My version replaces those mechanisms with multiple hash table lookups and use of the Reflection API so does not offer the same level of performance. It also allocates from the garbage-collected heap as it runs, with the limit of the allocation load hard to determine, and spits out a little garbage for every transition.

• Source Code

I've also re-implemented the Calculator main motivating example statechart used in that book as a web applet: