Added in API level 1

AtomicReference

open class AtomicReference<V : Any!> : Serializable

kotlin.Any
↳	java.util.concurrent.atomic.AtomicReference

An object reference that may be updated atomically. See the VarHandle specification for descriptions of the properties of atomic accesses.

Summary

Public constructors
`AtomicReference(initialValue: V)` Creates a new AtomicReference with the given initial value.
`AtomicReference()` Creates a new AtomicReference with null initial value.

Public methods
V	`accumulateAndGet(x: V, accumulatorFunction: BinaryOperator<V>!)` Atomically updates (with memory effects as specified by `java.lang.invoke.VarHandle#compareAndSet`) the current value with the results of applying the given function to the current and given values, returning the updated value.
V	`compareAndExchange(expectedValue: V, newValue: V)` Atomically sets the value to `newValue` if the current value, referred to as the witness value, `== expectedValue`, with memory effects as specified by `VarHandle#compareAndExchange`.
V	`compareAndExchangeAcquire(expectedValue: V, newValue: V)` Atomically sets the value to `newValue` if the current value, referred to as the witness value, `== expectedValue`, with memory effects as specified by `VarHandle#compareAndExchangeAcquire`.
V	`compareAndExchangeRelease(expectedValue: V, newValue: V)` Atomically sets the value to `newValue` if the current value, referred to as the witness value, `== expectedValue`, with memory effects as specified by `VarHandle#compareAndExchangeRelease`.
Boolean	`compareAndSet(expectedValue: V, newValue: V)` Atomically sets the value to `newValue` if the current value `== expectedValue`, with memory effects as specified by `VarHandle#compareAndSet`.
V	`get()` Returns the current value, with memory effects as specified by `VarHandle#getVolatile`.
V	`getAcquire()` Returns the current value, with memory effects as specified by `VarHandle#getAcquire`.
V	`getAndAccumulate(x: V, accumulatorFunction: BinaryOperator<V>!)` Atomically updates (with memory effects as specified by `java.lang.invoke.VarHandle#compareAndSet`) the current value with the results of applying the given function to the current and given values, returning the previous value.
V	`getAndSet(newValue: V)` Atomically sets the value to `newValue` and returns the old value, with memory effects as specified by `VarHandle#getAndSet`.
V	`getAndUpdate(updateFunction: UnaryOperator<V>!)` Atomically updates (with memory effects as specified by `java.lang.invoke.VarHandle#compareAndSet`) the current value with the results of applying the given function, returning the previous value.
V	`getOpaque()` Returns the current value, with memory effects as specified by `VarHandle#getOpaque`.
V	`getPlain()` Returns the current value, with memory semantics of reading as if the variable was declared non-`volatile`.
Unit	`lazySet(newValue: V)` Sets the value to `newValue`, with memory effects as specified by `VarHandle#setRelease`.
Unit	`set(newValue: V)` Sets the value to `newValue`, with memory effects as specified by `VarHandle#setVolatile`.
Unit	`setOpaque(newValue: V)` Sets the value to `newValue`, with memory effects as specified by `VarHandle#setOpaque`.
Unit	`setPlain(newValue: V)` Sets the value to `newValue`, with memory semantics of setting as if the variable was declared non-`volatile` and non-`final`.
Unit	`setRelease(newValue: V)` Sets the value to `newValue`, with memory effects as specified by `VarHandle#setRelease`.
open String	`toString()` Returns the String representation of the current value.
V	`updateAndGet(updateFunction: UnaryOperator<V>!)` Atomically updates (with memory effects as specified by `java.lang.invoke.VarHandle#compareAndSet`) the current value with the results of applying the given function, returning the updated value.
Boolean	`weakCompareAndSet(expectedValue: V, newValue: V)` Possibly atomically sets the value to `newValue` if the current value `== expectedValue`, with memory effects as specified by `VarHandle#weakCompareAndSetPlain`.
Boolean	`weakCompareAndSetAcquire(expectedValue: V, newValue: V)` Possibly atomically sets the value to `newValue` if the current value `== expectedValue`, with memory effects as specified by `VarHandle#weakCompareAndSetAcquire`.
Boolean	`weakCompareAndSetPlain(expectedValue: V, newValue: V)` Possibly atomically sets the value to `newValue` if the current value `== expectedValue`, with memory effects as specified by `VarHandle#weakCompareAndSetPlain`.
Boolean	`weakCompareAndSetRelease(expectedValue: V, newValue: V)` Possibly atomically sets the value to `newValue` if the current value `== expectedValue`, with memory effects as specified by `VarHandle#weakCompareAndSetRelease`.
Boolean	`weakCompareAndSetVolatile(expectedValue: V, newValue: V)` Possibly atomically sets the value to `newValue` if the current value `== expectedValue`, with memory effects as specified by `VarHandle#weakCompareAndSet`.

Public constructors

AtomicReference

Added in API level 1

AtomicReference(initialValue: V)

Creates a new AtomicReference with the given initial value.

Parameters
`initialValue`	V: the initial value

AtomicReference

Added in API level 1

AtomicReference()

Creates a new AtomicReference with null initial value.

Public methods

accumulateAndGet

Added in API level 24

fun accumulateAndGet(
    x: V, 
    accumulatorFunction: BinaryOperator<V>!
): V

Atomically updates (with memory effects as specified by java.lang.invoke.VarHandle#compareAndSet) the current value with the results of applying the given function to the current and given values, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value as its first argument, and the given update as the second argument.

Parameters
`x`	V: the update value
`accumulatorFunction`	BinaryOperator<V>!: a side-effect-free function of two arguments

Return
`V`	the updated value

compareAndExchange

Added in API level 33

fun compareAndExchange(
    expectedValue: V, 
    newValue: V
): V

Atomically sets the value to newValue if the current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle#compareAndExchange.

Parameters
`expectedValue`	V: the expected value
`newValue`	V: the new value

Return
`V`	the witness value, which will be the same as the expected value if successful

compareAndExchangeAcquire

Added in API level 33

fun compareAndExchangeAcquire(
    expectedValue: V, 
    newValue: V
): V

Atomically sets the value to newValue if the current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle#compareAndExchangeAcquire.

Parameters
`expectedValue`	V: the expected value
`newValue`	V: the new value

Return
`V`	the witness value, which will be the same as the expected value if successful

compareAndExchangeRelease

Added in API level 33

fun compareAndExchangeRelease(
    expectedValue: V, 
    newValue: V
): V

Atomically sets the value to newValue if the current value, referred to as the witness value, == expectedValue, with memory effects as specified by VarHandle#compareAndExchangeRelease.

Parameters
`expectedValue`	V: the expected value
`newValue`	V: the new value

Return
`V`	the witness value, which will be the same as the expected value if successful

compareAndSet

Added in API level 1

fun compareAndSet(
    expectedValue: V, 
    newValue: V
): Boolean

Atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle#compareAndSet.

Parameters
`expectedValue`	V: the expected value
`newValue`	V: the new value

Return
`Boolean`	`true` if successful. False return indicates that the actual value was not equal to the expected value.

get

Added in API level 1

fun get(): V

Returns the current value, with memory effects as specified by VarHandle#getVolatile.

Return
`V`	the current value

getAcquire

Added in API level 33

fun getAcquire(): V

Returns the current value, with memory effects as specified by VarHandle#getAcquire.

Return
`V`	the value

getAndAccumulate

Added in API level 24

fun getAndAccumulate(
    x: V, 
    accumulatorFunction: BinaryOperator<V>!
): V

Atomically updates (with memory effects as specified by java.lang.invoke.VarHandle#compareAndSet) the current value with the results of applying the given function to the current and given values, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads. The function is applied with the current value as its first argument, and the given update as the second argument.

Parameters
`x`	V: the update value
`accumulatorFunction`	BinaryOperator<V>!: a side-effect-free function of two arguments

Return
`V`	the previous value

getAndSet

Added in API level 1

fun getAndSet(newValue: V): V

Atomically sets the value to newValue and returns the old value, with memory effects as specified by VarHandle#getAndSet.

Parameters
`newValue`	V: the new value

Return
`V`	the previous value

getAndUpdate

Added in API level 24

fun getAndUpdate(updateFunction: UnaryOperator<V>!): V

Atomically updates (with memory effects as specified by java.lang.invoke.VarHandle#compareAndSet) the current value with the results of applying the given function, returning the previous value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.

Parameters
`updateFunction`	UnaryOperator<V>!: a side-effect-free function

Return
`V`	the previous value

getOpaque

Added in API level 33

fun getOpaque(): V

Returns the current value, with memory effects as specified by VarHandle#getOpaque.

Return
`V`	the value

getPlain

Added in API level 33

fun getPlain(): V

Returns the current value, with memory semantics of reading as if the variable was declared non-volatile.

Return
`V`	the value

lazySet

Added in API level 9

fun lazySet(newValue: V): Unit

Sets the value to newValue, with memory effects as specified by VarHandle#setRelease.

Parameters
`newValue`	V: the new value

set

Added in API level 1

fun set(newValue: V): Unit

Sets the value to newValue, with memory effects as specified by VarHandle#setVolatile.

Parameters
`newValue`	V: the new value

setOpaque

Added in API level 33

fun setOpaque(newValue: V): Unit

Sets the value to newValue, with memory effects as specified by VarHandle#setOpaque.

Parameters
`newValue`	V: the new value

setPlain

Added in API level 33

fun setPlain(newValue: V): Unit

Sets the value to newValue, with memory semantics of setting as if the variable was declared non-volatile and non-final.

Parameters
`newValue`	V: the new value

setRelease

Added in API level 33

fun setRelease(newValue: V): Unit

Sets the value to newValue, with memory effects as specified by VarHandle#setRelease.

Parameters
`newValue`	V: the new value

toString

Added in API level 1

open fun toString(): String

Returns the String representation of the current value.

Return
`String`	the String representation of the current value

updateAndGet

Added in API level 24

fun updateAndGet(updateFunction: UnaryOperator<V>!): V

Atomically updates (with memory effects as specified by java.lang.invoke.VarHandle#compareAndSet) the current value with the results of applying the given function, returning the updated value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.

Parameters
`updateFunction`	UnaryOperator<V>!: a side-effect-free function

Return
`V`	the updated value

weakCompareAndSet

Added in API level 1
Deprecated in API level 33

fun weakCompareAndSet(
    expectedValue: V, 
    newValue: V
): Boolean

Deprecated: This method has plain memory effects but the method name implies volatile memory effects (see methods such as compareAndExchange and compareAndSet). To avoid confusion over plain or volatile memory effects it is recommended that the method weakCompareAndSetPlain be used instead.

Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle#weakCompareAndSetPlain.

Parameters
`expectedValue`	V: the expected value
`newValue`	V: the new value

Return
`Boolean`	`true` if successful

See Also

#weakCompareAndSetPlain

weakCompareAndSetAcquire

Added in API level 33

fun weakCompareAndSetAcquire(
    expectedValue: V, 
    newValue: V
): Boolean

Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle#weakCompareAndSetAcquire.

Parameters
`expectedValue`	V: the expected value
`newValue`	V: the new value

Return
`Boolean`	`true` if successful

weakCompareAndSetPlain

Added in API level 33

fun weakCompareAndSetPlain(
    expectedValue: V, 
    newValue: V
): Boolean

Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle#weakCompareAndSetPlain.

Parameters
`expectedValue`	V: the expected value
`newValue`	V: the new value

Return
`Boolean`	`true` if successful

weakCompareAndSetRelease

Added in API level 33

fun weakCompareAndSetRelease(
    expectedValue: V, 
    newValue: V
): Boolean

Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle#weakCompareAndSetRelease.

Parameters
`expectedValue`	V: the expected value
`newValue`	V: the new value

Return
`Boolean`	`true` if successful

weakCompareAndSetVolatile

Added in API level 33

fun weakCompareAndSetVolatile(
    expectedValue: V, 
    newValue: V
): Boolean

Possibly atomically sets the value to newValue if the current value == expectedValue, with memory effects as specified by VarHandle#weakCompareAndSet.

Parameters
`expectedValue`	V: the expected value
`newValue`	V: the new value

Return
`Boolean`	`true` if successful