[clavigne]

Scala async coroutines build FSMs that are just standard objects. They aren't very commonly used, but the same approach could probably be adapted to C.

Basically the compiler compiles async function to a very simple FSM object where each assignment to a local variable that lives longer than a yield point becomes a member of the FSM object. This is done after the transformation to a simple normal form, at which point the function basically looks like bytecode. The compiler generate a new class for every async coroutines.

The generated FSM classes are statically sized so they could in principle be stack allocated, and their instances can be manipulated like any other JVM object.

At $work we have a system using scala async that has all of these features (arrays of FSMs, serialization, distribution by sending to network etc.) Of course there are complications (file handles for example) and it's easier with a GC.