AtomicReference (Java Platform SE 8 ) (original) (raw)

• java.lang.Object

• • java.util.concurrent.atomic.AtomicReference

• Type Parameters:
  V - The type of object referred to by this reference
  All Implemented Interfaces:
  Serializable

public class AtomicReference
extends Object
implements Serializable
An object reference that may be updated atomically. See the java.util.concurrent.atomic package specification for description of the properties of atomic variables.
Since:
1.5
See Also:
Serialized Form

• • Constructor Summary

  Constructors

  Constructor	Description
  AtomicReference()	Creates a new AtomicReference with null initial value.
  AtomicReference(V initialValue)	Creates a new AtomicReference with the given initial value.

  • Method Summary

  All Methods Instance Methods Concrete Methods

  Modifier and Type	Method	Description
  V	accumulateAndGet(V x,BinaryOperator<V> accumulatorFunction)	Atomically updates the current value with the results of applying the given function to the current and given values, returning the updated value.
  boolean	compareAndSet(V expect,V update)	Atomically sets the value to the given updated value if the current value == the expected value.
  V	get()	Gets the current value.
  V	getAndAccumulate(V x,BinaryOperator<V> accumulatorFunction)	Atomically updates the current value with the results of applying the given function to the current and given values, returning the previous value.
  V	getAndSet(V newValue)	Atomically sets to the given value and returns the old value.
  V	getAndUpdate(UnaryOperator<V> updateFunction)	Atomically updates the current value with the results of applying the given function, returning the previous value.
  void	lazySet(V newValue)	Eventually sets to the given value.
  void	set(V newValue)	Sets to the given value.
  String	toString()	Returns the String representation of the current value.
  V	updateAndGet(UnaryOperator<V> updateFunction)	Atomically updates the current value with the results of applying the given function, returning the updated value.
  boolean	weakCompareAndSet(V expect,V update)	Atomically sets the value to the given updated value if the current value == the expected value.

     * ### Methods inherited from class java.lang.[Object](../../../../java/lang/Object.html "class in java.lang")  
     `[clone](../../../../java/lang/Object.html#clone--), [equals](../../../../java/lang/Object.html#equals-java.lang.Object-), [finalize](../../../../java/lang/Object.html#finalize--), [getClass](../../../../java/lang/Object.html#getClass--), [hashCode](../../../../java/lang/Object.html#hashCode--), [notify](../../../../java/lang/Object.html#notify--), [notifyAll](../../../../java/lang/Object.html#notifyAll--), [wait](../../../../java/lang/Object.html#wait--), [wait](../../../../java/lang/Object.html#wait-long-), [wait](../../../../java/lang/Object.html#wait-long-int-)`

• • Constructor Detail

     * #### AtomicReference  
     public AtomicReference([V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") initialValue)  
     Creates a new AtomicReference with the given initial value.  
     Parameters:  
     `initialValue` \- the initial value  
     * #### AtomicReference  
     public AtomicReference()  
     Creates a new AtomicReference with null initial value.  

  • Method Detail

    * #### get  
    public final [V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") get()  
    Gets the current value.  
    Returns:  
    the current value  
    * #### set  
    public final void set([V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") newValue)  
    Sets to the given value.  
    Parameters:  
    `newValue` \- the new value  
    * #### lazySet  
    public final void lazySet([V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") newValue)  
    Eventually sets to the given value.  
    Parameters:  
    `newValue` \- the new value  
    Since:  
    1.6  
    * #### compareAndSet  
    public final boolean compareAndSet([V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") expect,  
                                       [V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") update)  
    Atomically sets the value to the given updated value if the current value `==` the expected value.  
    Parameters:  
    `expect` \- the expected value  
    `update` \- the new value  
    Returns:  
    `true` if successful. False return indicates that the actual value was not equal to the expected value.  
    * #### weakCompareAndSet  
    public final boolean weakCompareAndSet([V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") expect,  
                                           [V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") update)  
    Parameters:  
    `expect` \- the expected value  
    `update` \- the new value  
    Returns:  
    `true` if successful  
    * #### getAndSet  
    public final [V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") getAndSet([V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") newValue)  
    Atomically sets to the given value and returns the old value.  
    Parameters:  
    `newValue` \- the new value  
    Returns:  
    the previous value  
    * #### getAndUpdate  
    public final [V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") getAndUpdate([UnaryOperator](../../../../java/util/function/UnaryOperator.html "interface in java.util.function")<[V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference")> updateFunction)  
    Atomically updates 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` \- a side-effect-free function  
    Returns:  
    the previous value  
    Since:  
    1.8  
    * #### updateAndGet  
    public final [V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") updateAndGet([UnaryOperator](../../../../java/util/function/UnaryOperator.html "interface in java.util.function")<[V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference")> updateFunction)  
    Atomically updates 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` \- a side-effect-free function  
    Returns:  
    the updated value  
    Since:  
    1.8  
    * #### getAndAccumulate  
    public final [V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") getAndAccumulate([V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") x,  
                                    [BinaryOperator](../../../../java/util/function/BinaryOperator.html "interface in java.util.function")<[V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference")> accumulatorFunction)  
    Atomically updates 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` \- the update value  
    `accumulatorFunction` \- a side-effect-free function of two arguments  
    Returns:  
    the previous value  
    Since:  
    1.8  
    * #### accumulateAndGet  
    public final [V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") accumulateAndGet([V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference") x,  
                                    [BinaryOperator](../../../../java/util/function/BinaryOperator.html "interface in java.util.function")<[V](../../../../java/util/concurrent/atomic/AtomicReference.html "type parameter in AtomicReference")> accumulatorFunction)  
    Atomically updates 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` \- the update value  
    `accumulatorFunction` \- a side-effect-free function of two arguments  
    Returns:  
    the updated value  
    Since:  
    1.8  
    * #### toString  
    public [String](../../../../java/lang/String.html "class in java.lang") toString()  
    Returns the String representation of the current value.  
    Overrides:  
    `[toString](../../../../java/lang/Object.html#toString--)` in class `[Object](../../../../java/lang/Object.html "class in java.lang")`  
    Returns:  
    the String representation of the current value

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