package 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 API compatibility purposes and because it's a useful way to box a value.
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.
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[A]):
val atomicNumber = Atomic(12.2) atomicNumber.incrementAndGet() // => 13.2
These also provide useful helpers for atomically mutating of
values (i.e. transform, transformAndGet, getAndTransform,
etc...) or of numbers of any kind (incrementAndGet, getAndAdd,
etc...).
- Alphabetic
- By Inheritance
- atomic
- AnyRef
- Any
- Hide All
- Show All
- Public
- All
Type Members
-
abstract
class
Atomic[A] extends Serializable
Base trait of all atomic references, no matter the type.
-
final
class
AtomicAny[A <: AnyRef] extends Atomic[A]
Atomic references wrapping
AnyRefvalues.Atomic references wrapping
AnyRefvalues.- A
is forced to be an
AnyRefbecause the equality test is by reference and not by value.
-
final
class
AtomicBoolean extends Atomic[Boolean]
Atomic references wrapping
Booleanvalues.Atomic references wrapping
Booleanvalues.Note that the equality test in
compareAndSetis value based, sinceBooleanis a primitive. -
trait
AtomicBuilder[A, R <: Atomic[A]] extends Serializable
For a given
Aindicates the most specificAtomic[A]reference type to use.For a given
Aindicates the most specificAtomic[A]reference type to use.In essence this is implementing a form of specialization driven by implicits.
-
final
class
AtomicByte extends AtomicNumber[Byte]
Atomic references wrapping
Bytevalues.Atomic references wrapping
Bytevalues.Note that the equality test in
compareAndSetis value based, sinceByteis a primitive. -
final
class
AtomicChar extends AtomicNumber[Char]
Atomic references wrapping
Charvalues.Atomic references wrapping
Charvalues.Note that the equality test in
compareAndSetis value based, sinceCharis a primitive. -
final
class
AtomicDouble extends AtomicNumber[Double]
Atomic references wrapping
Doublevalues.Atomic references wrapping
Doublevalues.Note that the equality test in
compareAndSetis value based, sinceDoubleis a primitive. -
final
class
AtomicFloat extends AtomicNumber[Float]
Atomic references wrapping
Floatvalues.Atomic references wrapping
Floatvalues.Note that the equality test in
compareAndSetis value based, sinceFloatis a primitive. -
final
class
AtomicInt extends AtomicNumber[Int]
Atomic references wrapping
Intvalues.Atomic references wrapping
Intvalues.Note that the equality test in
compareAndSetis value based, sinceIntis a primitive. -
final
class
AtomicLong extends AtomicNumber[Long]
Atomic references wrapping
Longvalues.Atomic references wrapping
Longvalues.Note that the equality test in
compareAndSetis value based, sinceLongis a primitive. -
abstract
class
AtomicNumber[A] extends Atomic[A]
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.
- A
should be something that's Numeric
-
final
class
AtomicNumberAny[A <: AnyRef] extends AtomicNumber[A]
Atomic references wrapping any values implementing Scala's
Numerictype class.Atomic references wrapping any values implementing Scala's
Numerictype class.Note that the equality test in
compareAndSetis reference based. This is because we are storingAnyRefreferences and on top of the JVM that's the semantic ofcompareAndSet. This behavior is kept consistent even on top of Scala.js / Javascript. -
final
class
AtomicShort extends AtomicNumber[Short]
Atomic references wrapping
Shortvalues.Atomic references wrapping
Shortvalues.Note that the equality test in
compareAndSetis value based, sinceShortis a primitive. -
sealed abstract
class
PaddingStrategy extends AnyRef
For applying padding to atomic references, in order to reduce cache contention.
For applying padding to atomic references, in order to reduce cache contention. JEP 142 should reduce the need for this along with the
@Contendedannotation, however that might have security restrictions, the runtime might not act on it since it's just a recommendation, plus it's nice to provide backwards compatibility.See: http://mail.openjdk.java.net/pipermail/hotspot-dev/2012-November/007309.html
The default strategy is NoPadding. In order to apply padding:
import monix.execution.atomic.Atomic import monix.execution.atomic.PaddingStrategy.Right64 val paddedAtomic = Atomic.withPadding(10, Right64)
Value Members
- object Atomic extends Serializable
- object AtomicAny extends Serializable
- object AtomicBoolean extends Serializable
- object AtomicBuilder extends Level2 with Serializable
- object AtomicByte extends Serializable
- object AtomicChar extends Serializable
- object AtomicDouble extends Serializable
- object AtomicFloat extends Serializable
- object AtomicInt extends Serializable
- object AtomicLong extends Serializable
- object AtomicNumberAny extends Serializable
- object AtomicShort extends Serializable
- object PaddingStrategy