Concurrency In Scala

Matthew Rathbone shows different concurrency options available in Scala:

Scala is a functional programming language that aims to avoid side effects by encouraging you to use immutable variables (called ‘values’), and data structures.

So by default in Scala when you build a list, array, string, or other object, that object is immutable and cannot be changed or updated.

This might seem unrelated, but think about a thread which has been given a list of strings to process, perhaps each string is a website that needs crawling.

In the Java model, this list might be updated by other threads at the same time (adding / removing websites), so you need to make sure you either have a thread-safe list, or you safeguard access to it with the protected keyword or a Mutex.

By default in Scala this list is immutable, so you can be sure that the list cannot be modified by other threads, because it cannot be modified at all.

While this does force you to program in different ways to work around the immutability, it does have the tremendous effect of simplifying thread-safety concerns. The value of this cannot be understated, it’s a huge burden to worry about thread safety all the time, but in Scala much of that burden goes away.

Read the whole thing if you’re looking at writing Spark applications in Scala.  If you’re thinking about functional programming in .NET languages, F# is  there for you.

Related Posts

The Decorator Pattern

Nancy Jain explains the Decorator pattern: Decorator design pattern is a structural design pattern. Structural design patterns focus on Class and Object composition and decorator design pattern is about adding responsibilities to objects dynamically. Decorator design pattern gives some additional responsibility to our base class. This pattern is about creating a decorator class that can […]

Read More

Why .NET And Java Have StringBuilders

Randolph West walks us through a performance troubleshooting issue with a twist: So we branch the the code in source control, and start writing a helper class to manage the data for us closer to the application. We throw in a SqlDataAdapter, use the Fill() method to bring back all the rows from the query in one go, and then […]

Read More

Categories

March 2017
MTWTFSS
« Feb Apr »
 12345
6789101112
13141516171819
20212223242526
2728293031