AtomicReference weakCompareAndSetPlain() method in Java with Examples

The weakCompareAndSetPlain() method of a AtomicReference class is used to atomically sets the value to newValue for AtomicReference if the current value is equal to expectedValue passed as parameter. This method updates the value with memory semantics of setting as if the variable was declared non-volatile and non-final.This method returns true if set a new value to AtomicReference is successful. Syntax:

public final boolean
       weakCompareAndSetPlain(V expectedValue,
                              V newValue)

Parameters: This method accepts expectedValue which is the expected value and newValue which is the new value to set. Return value: This method returns true if successful. Below programs illustrate the weakCompareAndSetPlain() method: Program 1:

Java

// Java program to demonstrate
// AtomicReference.weakCompareAndSetPlain() method

import java.util.concurrent.atomic.AtomicReference;

public class GFG {
    public static void main(String[] args)
    {

        // create an atomic reference object
        // which stores Integer.
        AtomicReference<Long> ref
            = new AtomicReference<Long>();

        // set some value
        ref.set(1234L);

        // apply weakCompareAndSetPlain()
        boolean result
            = ref.weakCompareAndSetPlain(
                1111L,
                999999L);

        // print value
        System.out.println("Setting new value"
                           + " is successful = "
                           + result);
        System.out.println("Value = " + ref.get());
    }
}

Output:

Program 2:

Java

// Java program to demonstrate
// AtomicReference.weakCompareAndSetPlain() method

import java.util.concurrent.atomic.AtomicReference;

public class GFG {
    public static void main(String[] args)
    {
        // create an atomic reference object
        // which stores String.
        AtomicReference<String> ref
            = new AtomicReference<String>();

        // set some value
        ref.set("WELCOME TO GEEKS FOR GEEKS");

        // apply weakCompareAndSetPlain()
        boolean result
            = ref.weakCompareAndSetPlain(
                "WELCOME TO GEEKS FOR GEEKS",
                "GFG GEEKS");

        // print value
        System.out.println("Setting new value"
                           + " is successful = "
                           + result);
        System.out.println("Value  = " + ref.get());
    }
}

Output:

References: https://docs.oracle.com/javase/10/docs/api/java/util/concurrent/atomic/AtomicReference.html#weakCompareAndSetPlain(V, V)