Great question! Your core idea—using OS processes (with PID as the actor address), IPC for message passing, and spawning new processes to create actors—is a valid starting point for a naive actor-like system, but there are several key Actor Model properties you might not have considered that are required to align with the formal definition of the model. Let’s break them down:

Key Actor Model Properties You’re Missing (or Need to Explicitly Implement) #

• Serial, Single-Threaded Message Processing
  A fundamental rule of the Actor Model is that an actor processes one message at a time, in the order they’re received. While OS processes give you isolation, if your process spins up multiple threads to handle incoming IPC messages, you’ll break this seriality—leading to race conditions on the actor’s internal state. You must enforce that each process (actor) uses a single thread to pull and process messages from its IPC queue, with no concurrent handling.

• Supervision & Fault Tolerance
  Actor systems rely on a supervision hierarchy to handle failures: parent actors monitor their children, and can restart, terminate, or adjust the behavior of child actors if they crash. OS processes do provide isolation (one process crashing won’t take down others), but the OS doesn’t natively implement this actor-specific supervision logic. You’d need to build your own mechanism to track process health, detect crashes, and trigger recovery actions based on defined policies.

• Location Transparency
  The Actor Model abstracts away an actor’s physical location—you should be able to send a message to an actor whether it’s running locally on the same machine or remotely on another node. Using PIDs as addresses ties actors to local OS processes, making it impossible to extend your system to a distributed environment without a layer of abstraction over the address space. Real actor frameworks (like Erlang/OTP) use abstract actor references that route messages transparently, regardless of location.

• Guaranteed Asynchronous Message Sending
  Actor Model requires that sending a message is a non-blocking, fire-and-forget operation. While many IPC mechanisms (like message queues, async sockets) support this, some synchronous IPC methods (e.g., blocking pipe reads/writes) would force the sender to wait for the receiver, violating this property. You need to ensure all message sends are fully asynchronous and don’t block the sender’s execution.

What You’re Already Getting Right #

To be clear, your approach does hit some core Actor Model marks:

• Isolation: Processes don’t share memory, so actors can only interact via messages (no direct state access from outside).
• Unique Addressing: PIDs act as unique identifiers for each actor, enabling targeted message sending.
• Spawnability: Creating a new process maps directly to spawning a new actor.

Summary #

Using OS processes + IPC can work for a simple, local actor system, but to build a fully compliant Actor Model implementation, you’ll need to add the missing properties outlined above. For most production use cases, leveraging existing actor frameworks (like Akka, Erlang/OTP) is more practical, as they handle these details out of the box—but your approach is a great way to understand the foundational mechanics of the model.

内容的提问来源于stack exchange，提问作者Citrullin