Actors in SALSA

SALSA programmers write behaviors which include encapsulated state and message handlers for actor instances:

• New actors get created in SALSA by instantiating particular behaviors (with the new keyword). Creating an actor returns its reference.

• The message sending operator (<-) is used to send messages to actors; messages contain a name that refers to the message handler for the message and optionally a list of arguments.

• Actors, once created, process incoming messages, one at a time.

While SALSA supports the actor model, it goes further in providing linguistic abstractions for common coordination patterns in concurrent and distributed applications. For concurrency, it provides token passing continuations, join blocks, first-class continuations, named tokens, and message properties. For distribution, remote actor creation, and remote referencing, it provides universal naming abstractions, location-transparent communication, and migration support. Furthermore, SALSA provides automatic local and distributed garbage collection.