In concurrent computation, the actor model uses the actor as the basic building block. An actor can:
- make local decisions
- create more actors
- send more messages
- determine how to respond to the next message received
They can modify their own private state, but they affect others only through messages.
References
See also
- A process in operating systems is a program in execution — an actor is conceptually a process: isolated state, no shared memory, communicates with the outside world through well-defined channels
- A Context Switch Saves the PCB of the Running Process and Restores Another — actor runtimes (like Erlang’s BEAM) implement lightweight context switching between actors, analogous to OS context switching but at much lower cost
- The process scheduler chooses an available process — actor runtimes implement their own scheduler to dispatch messages to actors, mirroring the OS scheduler’s role for processes
- Functional Programming programs are trees of expressions, not sequences of steps — actors share the functional programming principle of avoiding shared mutable state; the difference is that FP eliminates state mutation entirely, actors isolate it per actor
- Reliability means preventing faults from causing failures — the actor model’s fault isolation is a direct mechanism for the reliability principle: a crashing actor (fault) doesn’t bring down the system (failure); process isolation is listed there as a key reliability strategy