atomic

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

On top of the JVM, this means dealing with lock-free thread-safe programming. Also works on top of Javascript, with Scala.js (for good reasons, as Atomic references are still useful in non-multi-threaded environments).

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. They also support weak operations, defined in WeakAtomic[T], such as (e.g. weakCompareAndSet, lazySet) or operations that block the current thread through spin-locking, until a condition happens (e.g. waitForCompareAndSet), methods exposed by BlockingAtomic[T].

Building a reference is easy with the provided constructor, which will automatically return the most specific type needed (in the following sample, that's an AtomicDouble, inheriting from AtomicNumber[T]):

val atomicNumber = Atomic(12.2)

atomicNumber.incrementAndGet()
// => 13.2

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

A high-level documentation describing the rationale for these can be found here: Atomic Reference

Linear Supertypes

AnyRef, Any

Type Members

trait Atomic[T] extends Any

Base trait of all atomic references, no matter the type.
final class AtomicAny[T] extends BlockableAtomic[T]
final class AtomicBoolean extends BlockableAtomic[Boolean]
trait AtomicBuilder[T, R <: Atomic[T]] extends AnyRef
final class AtomicByte extends AtomicNumber[Byte] with BlockableAtomic[Byte]
final class AtomicChar extends AtomicNumber[Char] with BlockableAtomic[Char]
final class AtomicDouble extends AtomicNumber[Double] with BlockableAtomic[Double]
final class AtomicFloat extends AtomicNumber[Float] with BlockableAtomic[Float]
final class AtomicInt extends AtomicNumber[Int] with BlockableAtomic[Int]
final class AtomicLong extends AtomicNumber[Long] with BlockableAtomic[Long]
trait AtomicNumber[T] extends Atomic[T]

Represents an Atomic reference holding a number, providing helpers for easily incrementing and decrementing it.
Represents an Atomic reference holding a number, providing helpers for easily incrementing and decrementing it.
T
should be something that's Numeric
final class AtomicNumberAny[T] extends AtomicNumber[T] with BlockableAtomic[T]
final class AtomicShort extends AtomicNumber[Short] with BlockableAtomic[Short]
trait BlockableAtomic[T] extends Atomic[T]

Represents Atomic references that can block the thread (with spin-locking) in wait of a successful condition (is not supported on top of Scala.
Represents Atomic references that can block the thread (with spin-locking) in wait of a successful condition (is not supported on top of Scala.js).
Useful when using an Atomic reference as a locking mechanism.

Value Members

object Atomic
object AtomicAny
object AtomicBoolean
object AtomicBuilder extends Level3
object AtomicByte
object AtomicChar
object AtomicDouble
object AtomicFloat
object AtomicInt
object AtomicLong
object AtomicNumber
object AtomicNumberAny
object AtomicShort
package padded

Atomic classes that are cache-padded for reducing cache contention, until JEP 142 and @Contended happens.
Atomic classes that are cache-padded for reducing cache contention, until JEP 142 and @Contended happens. See:
http://mail.openjdk.java.net/pipermail/hotspot-dev/2012-November/007309.html

package atomic

Type Members

trait Atomic[T] extends Any

final class AtomicAny[T] extends BlockableAtomic[T]

final class AtomicBoolean extends BlockableAtomic[Boolean]

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

final class AtomicByte extends AtomicNumber[Byte] with BlockableAtomic[Byte]

final class AtomicChar extends AtomicNumber[Char] with BlockableAtomic[Char]

final class AtomicDouble extends AtomicNumber[Double] with BlockableAtomic[Double]

final class AtomicFloat extends AtomicNumber[Float] with BlockableAtomic[Float]

final class AtomicInt extends AtomicNumber[Int] with BlockableAtomic[Int]

final class AtomicLong extends AtomicNumber[Long] with BlockableAtomic[Long]

trait AtomicNumber[T] extends Atomic[T]

final class AtomicNumberAny[T] extends AtomicNumber[T] with BlockableAtomic[T]

final class AtomicShort extends AtomicNumber[Short] with BlockableAtomic[Short]

trait BlockableAtomic[T] extends Atomic[T]

Value Members

object Atomic

object AtomicAny

object AtomicBoolean

object AtomicBuilder extends Level3

object AtomicByte

object AtomicChar

object AtomicDouble

object AtomicFloat

object AtomicInt

object AtomicLong

object AtomicNumber

object AtomicNumberAny

object AtomicShort

package padded

Inherited from AnyRef

Inherited from Any

Ungrouped