[Book]: Actors in Scala

Actors in Scala

Table of contents:
Contents viii
List of Figures x
List of Listings xi
Preface xiii
1. Concurrency Everywhere 15 (download free sample chapter PDF)
2. Messages All the Way Up 25
3. Scala's Language Support for Actors 41
4. Actor Chat 42
5. Event-Based Programming 52
6. Exception Handling, Actor Termination and Shutdown 65
7. Customizing Actor Execution 80
8. Remote Actors 95
9. Using Scala Actors with Java APIs 96
10. Distributed and Parallel Computing with Scala Actors 97
Bibliography 98
About the Authors 100
Index 101

State: You're Doing It Wrong - Alternative Concurrency Paradigms For The JVM

"State: You're Doing It Wrong - Alternative Concurrency Paradigms For The JVM"

"What is an Identity?
A stable logical Identity associated with a series of different Values over time."

"What is State?
The Value an entity with a specific Identity has at a particular point in time."

"Haw do we know if something has State?
If a function is invoked with the same arguments at two different points in time and returns different values ... than it has State."

P.S. More on State (Clojure)

Akka - an open source, event-driven middleware project

"Akka - an open source, event-driven middleware project"

"... It is designed to allow developers to write simpler, correct concurrent applications using Actors, STM (software transactional memory) and transactors."

Event-Based Programming without Inversion of Control

"Event-Based Programming without Inversion of Control" from Philipp Haller, Martin Odersky(He designed the Scala programming language and Generic Java).
"...
Most programming models support event-driven programming only through inversion of control. Instead of calling blocking operations (e.g. for obtaining user input), a program merely registers its interest to be resumed on certain events (e.g. an event signaling a pressed button, or changed contents of a text eld). In the process, event handlers are installed in the execution environment which are called when certain events occur. The program never calls these event handlers itself. Instead, the execution environment dispatches events to the installed handlers. Thus, control over the execution of program logic is .

Virtually all approaches based on inversion of control suer from the following two problems: First, the interactive logic of a program is fragmented across multiple event handlers (or classes, as in the state design pattern [13]). Second, control ow among handlers is expressed implicitly through manipulation of shared state [10].
..."

A Survey of Concurrency Constructs

В презентации от SUN "A Survey of Concurrency Constructs" рассматриваются различные подходы в утилизации многоядерности + перечисляются плюсы/минусы каждого подхода:
- Threads/Locks
- Actors
- Dataflow
- Tuple spaces