AtomicLongArray updateAndGet() method in Java with Examples

The Java.util.concurrent.atomic.AtomicLongArray.updateAndGet() is an inbuilt method in Java that updates the value at any given index of the AtomicLongArray after applying a given update function on the value at that index. The method takes the index value of the AtomicLongArray and the update function as the parameters and updates the value at that index by applying the update function on that value. The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.

Syntax:

public final long updateAndGet(int i, LongUnaryOperator updateFunction)

Parameters: The function accepts two parameters:

  • i which is the index where update is to be made.
  • updateFunction which is the update function of single argument that tells what update is to be made.

    • Return value: The function returns a long value which is the value after applying the specified update function.

    Below programs illustrate the above method:
    Program 1:

    filter_none

    edit
    close

    play_arrow

    link
    brightness_4
    code

    // Java program that demonstrates
    // the updateAndGet() function
      
    import java.util.concurrent.atomic.AtomicLongArray;
    import java.util.function.LongUnaryOperator;
      
    public class GFG {
        public static void main(String args[])
        {
            // Initializing an array
            long a[] = { 1, 2, 3, 4, 5 };
      
            // Initializing an AtomicLongArray with array a
            AtomicLongArray arr = new AtomicLongArray(a);
      
            // Displaying the AtomicLongArray
            System.out.println("The array : " + arr);
      
            // Index where update is to be made
            int idx = 4;
      
            // Declaring the updateFunction
            LongUnaryOperator squaredFunction = (l) -> l * l;
      
            // Updating the value at idx
            // applying updateFunction
            arr.updateAndGet(idx, squaredFunction);
      
            // Displaying the AtomicLongArray
            System.out.println("The array after update : "
                               + arr);
        }
    }

    chevron_right

    

    

    
                        filter_none
    

    

    

    

    
Output:
    

    The array : [1, 2, 3, 4, 5]
The array after update : [1, 2, 3, 4, 25]

    

    

    Program 2:
    

    

    

    

    

    
                                    filter_none
    

    

                                        edit
    
                                    close
    

    

                                        play_arrow
    

    

                                        link
    
                                    brightness_4
    
                                    code
                                
    

    

    

    

    

    

    


    


    

    // Java program that demonstrates 
    

    // the updateAndGet() function 
    

      
    

    import java.util.concurrent.atomic.AtomicLongArray; 
    

    import java.util.function.LongUnaryOperator; 
    

      
    

    public class GFG { 
    

        public static void main(String args[]) 
    

        { 
    

            // Initializing an array 
    

            long a[] = { 1, 2, 3, 4, 5 }; 
    

      
    

            // Initializing an AtomicLongArray with array a 
    

            AtomicLongArray arr = new AtomicLongArray(a); 
    

      
    

            // Displaying the AtomicLongArray 
    

            System.out.println("The array : " + arr); 
    

      
    

            // Index where update is to be made 
    

            int idx = 3; 
    

      
    

            // Declaring the updateFunction 
    

            LongUnaryOperator cubeFunction = (l) -> l * l * l; 
    

      
    

            // Updating the value at idx 
    

            // applying updateFunction 
    

            arr.updateAndGet(idx, cubeFunction); 
    

      
    

            // Displaying the AtomicLongArray 
    

            System.out.println("The array after update : "
    

                               + arr); 
    

        } 
    

    } 
    

    
    		

    
    

    

    

    

    

    

    
                        chevron_right
    

    

    

    
                        filter_none
    

    

    

    

    
Output:
    

    The array : [1, 2, 3, 4, 5]
The array after update : [1, 2, 3, 64, 5]

    

    

    Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/atomic/AtomicLongArray.html#updateAndGet-int-java.util.function.LongUnaryOperator-
    

    
          
          
          
          
    
            
    
    
    
        My Personal Notes
        arrow_drop_up
    
    
    
    
        
        
    
            
            
        
    
    
    

    Recommended Posts:
    rupesh_rao
    Coder Machine Learner Social Activist Vocalist
    If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
    Please Improve this article if you find anything incorrect by clicking on  the "Improve Article" button below.