Finite-State Machine

The Finite-State Machine semantic module defines an entity lifecycle as states and allowed transitions. The parser validates the topology and derives event cardinality from it. The generated instrumentation APIs use that topology to enforce transition order.

For example, a task might move from queued to running, then to either completed or failed. Making that lifecycle part of the schema gives analysis tools enough meaning to detect unexpected transitions, find work that never reached a final state, and measure how long entities remained in each state. A user interface can also present the declared lifecycle and the observed path through it.

When an API must return an FSM whose current state is selected at runtime, the Dynamic state lesson shows how to preserve that state while moving transition validation to runtime.

The Resource lessons later show how an FSM state can declare the resources an entity uses while it remains in that state.