More Related Content
Similar to Actor model an approach to concurrency 1.0 (freiburg)
Similar to Actor model an approach to concurrency 1.0 (freiburg) (20)
Recently uploaded
Recently uploaded (20)
Actor model an approach to concurrency 1.0 (freiburg)
- 1. The Actor Model 1 An alternative approach to concurrency Lorenzo Nicora Senior Consultant @ OpenCredo @nicusX https://opencredo.com/author/lorenzo/
- 2. ✓ (1973) Carl Hewitt: “A Universal Modular Actor Formalism for Artificial Intelligence” 2 A bit of History… 1973 2009 ✓ (2009) Akka toolkit, Scala/Java ✓ (1986) Ericsson: Erlang Lorenzo Nicora Actor Model
- 3. According to Alan Kay, author of Smalltalk and inventor of the “Object-Orientation”: 3 The original idea of Object An “Object” ✓ Is the basic unit of object-oriented system ✓ Has its own state ✓ Communicate with others by sending and receiving messages* * in Java, C++, C# (derived from Simula, not Smalltalk) Objects interact by invoking methods 1980 Lorenzo Nicora Actor Model
- 4. An “Actor” is a computational entity that, in response to a message it receives, can concurrently: a) Send a finite number of messages to other actors b) Create a finite number of new actors c) Designate the behaviour to be used for the next message it receives. [implies a state] 4 The Actor Actor Actor Actor Mailbox Mailbox Mailbox Lorenzo Nicora Actor Model
- 5. Actors interacts only by messaging Actors react to messages 5 Actors are Reactive Lorenzo Nicora Actor Model
- 6. An Actor handles one message a time Never concurrently An Actor has a state State cannot be modified from outside the actor 6 Thread-safe An Actor is inherently thread-safe No Lock/Synchronisation on State Lorenzo Nicora Actor Model
- 7. 7 Supervision Actors are created by Actors Parent -> Child Lorenzo Nicora Actor Model
- 8. 8 Supervision Failure Handling • If a Child throws an Exception, the Supervisor get notified • Supervision Strategy: e.g. relaunch, abandon… Failure is always handled consistently Parent = Supervisor Lorenzo Nicora Actor Model
- 9. 9 Lightweight Actor is lightweight Creating an Actor has little overhead beyond creating an Object Lorenzo Nicora Actor Model
- 10. Non-blocking implementation of Request/Response pattern with multiple downstream collaborators 10 Example: Non-blocking Request/Response • One-Actor-per-Request pattern • Enterprise Integration Patterns: ✴ Request/Reply ✴ Return Address ✴ Scatter-Gather, Aggregators ✴ Round-robin Message Router Lorenzo Nicora Actor Model
- 11. 11 Example: Non-blocking Request/Response Lorenzo Nicora Actor Model
- 12. 12 Example: Non-blocking Request/Response Lorenzo Nicora Actor Model
- 13. 13 Example: Non-blocking Request/Response Lorenzo Nicora Actor Model
- 14. 14 Example: Non-blocking Request/Response Lorenzo Nicora Actor Model
- 15. 15 Example: Non-blocking Request/Response Lorenzo Nicora Actor Model
- 16. 16 Example: Non-blocking Request/Response Lorenzo Nicora Actor Model
- 17. 17 Example: Non-blocking Request/Response Lorenzo Nicora Actor Model
- 18. 18 Example: Non-blocking Request/Response Lorenzo Nicora Actor Model
- 19. 19 Example: Non-blocking Request/Response Lorenzo Nicora Actor Model
- 20. 20 Example: Non-blocking Request/Response Lorenzo Nicora Actor Model
- 21. 21 Example: Non-blocking Request/Response Lorenzo Nicora Actor Model
- 22. 22 Conclusions Actor model: an alternative approach to concurrency Actors, Threads + Business logic implementation + inherently thread-safe - A new programming paradigm - to learn Lorenzo Nicora Actor Model
- 23. 23 Lorenzo Nicora Actor Model