package atomic

A small toolkit of classes that support compare-and-swap semantics for mutation of variables.

On top of the JVM, this means dealing with lock-free thread-safe programming. On top of Javascript / Scala.js using Atomic references is still good because:

1. boxing values in a smart reference with nice helpers for transformations is always a good idea. 2. on the JVM there are times when synchronization, and when used for synchronization, atomic references can now cross compile to Scala.js 3. compareAndSet is actually a good idea to have even in an asynchronous, non-multi-threaded environment, such as Javascript, because it takes time into account and time related problems can happen even without multi-threading

The backbone of Atomic references is this method:

def compareAndSet(expect: T, update: T): Boolean

This method atomically sets a variable to the update value if it currently holds the expect value, reporting true on success or false on failure. The classes in this package also contain methods to get and unconditionally set values. In comparison with the JVM version, these Atomic references do not have methods for weakly setting values (i.e. weakCompareAndSet, lazySet), since those really make no sense in Javascript.

Building a reference is easy with the provided constructor, which will automatically return the most specific type needed:

val atomicNumber = Atomic(12L)


In comparison with java.util.concurrent.AtomicReference, these references implement common interfaces that you can use generically (i.e. Atomic[T], AtomicNumber[T]). And also provide useful helpers for atomically mutating of values (i.e. transform, transformAndGet, getAndTransform, etc...).

Other differences with the JVM-variant - in Scala.js you do not have access to the methods meant to block (spin-lock) the current thread (e.g. waitForCompareAndSet, waitForCondition, etc...), as the semantics of those operations aren't possible on top of Scala.js

Linear Supertypes
AnyRef, Any
  1. Alphabetic
  2. By inheritance
  1. atomic
  2. AnyRef
  3. Any
  1. Hide All
  2. Show all
Learn more about member selection
  1. Public
  2. All

Type Members

  1. trait Atomic[T] extends Any

    Base trait of all atomic references, no matter the type.

  2. final class AtomicAny[T] extends Atomic[T]

  3. type AtomicBoolean = AtomicAny[Boolean]

  4. trait AtomicBuilder[T, R <: Atomic[T]] extends AnyRef

  5. type AtomicByte = AtomicNumberAny[Byte]

  6. type AtomicChar = AtomicNumberAny[Char]

  7. type AtomicDouble = AtomicNumberAny[Double]

  8. type AtomicFloat = AtomicNumberAny[Float]

  9. type AtomicInt = AtomicNumberAny[Int]

  10. type AtomicLong = AtomicNumberAny[Long]

  11. trait AtomicNumber[T] extends Atomic[T]

    Represents an Atomic reference holding a number, providing helpers for easily incrementing and decrementing it.

  12. final class AtomicNumberAny[T] extends AtomicNumber[T]

  13. type AtomicShort = AtomicNumberAny[Short]

Value Members

  1. object Atomic

  2. object AtomicAny

  3. object AtomicBoolean

  4. object AtomicBuilder extends Level3

  5. object AtomicByte

  6. object AtomicChar

  7. object AtomicDouble

  8. object AtomicFloat

  9. object AtomicInt

  10. object AtomicLong

  11. object AtomicNumber

  12. object AtomicNumberAny

  13. object AtomicShort

  14. package padded

    Provided for source-level compatibility with the JVM version.

Inherited from AnyRef

Inherited from Any