The getAndSet() method of a AtomicReference class is used to atomically sets the value of AtomicReference object to newValue which is passed as parameter and returns the old value of the AtomicReference object, with memory effects as specified by VarHandle.getAndSet(java.lang.Object…).VarHandle.getAndSet(java.lang.Object…) specified that variable is handle as memory semantics of setting as if the variable was declared volatile.
Syntax:
public final V getAndSet?(V newValue)
Parameters: This method accepts newValue which is the new value.
Return value: This method returns the old value of AtomicReference.
Below programs illustrate the getAndSet() method:
Program 1:
Java
// Java program to demonstrate// AtomicReference.getAndSet() methodimport java.util.concurrent.atomic.AtomicReference;public class GFG { public static void main(String[] args) { // create an atomic reference object. AtomicReference<Double> ref = new AtomicReference<Double>(); // set some value ref.set(1234.00); // get and replace value double oldValue = ref.getAndSet((double)3213); // print System.out.println("OLD Value = " + oldValue); System.out.println("NEW Value = " + ref.get()); }} |
OLD Value = 1234.0 NEW Value = 3213.0
Program 2:
Java
// Java program to demonstrate// AtomicReference.getAndSet() methodimport java.util.concurrent.atomic.AtomicReference;public class GFG { public static void main(String[] args) { // create an atomic reference object. AtomicReference<String> ref = new AtomicReference<String>(); // set some value ref.set("AtomicReference old value"); // get and replace value String oldValue = ref.getAndSet( "AtomicReference new value"); // print System.out.println("OLD Value = " + oldValue); System.out.println("NEW Value = " + ref.get()); }} |
OLD Value = AtomicReference old value NEW Value = AtomicReference new value
References: https://docs.oracle.com/javase/10/docs/api/java/util/concurrent/atomic/AtomicReference.html#getAndSet(V)
