Thread: Optimizing Singleton Design Pattern

If you're not modifying the singleton (either externally or internally) then theoretically every thread can access the singleton mutually with no negative effects.

If you're able to partition the singleton into "sections" (for example, you have a 2D array and each thread operates on only a small block of the array), then again you can safely access the singleton without requiring synchronization.

If your threads require a complete lock on the singleton (or a partial lock that all threads need), then there's no optimization which can take place because at most only 1 thread can safely access the singleton. This is a design bottleneck and no amount of optimization can fix this. The only option is to redesign your application to avoid this case.

Without a more specific example (aka code) it's difficult to determine how to get more performance out of your code, or if this is even required.

Here is my singletonclss code

class SingletonClass {
 
	private static SingletonClass singletonObject;
	/** A private Constructor prevents any other class from instantiating. */
	private SingletonClass() {
		//	 Optional Code
	}
	public static synchronized SingletonClass getSingletonObject() {
		if (singletonObject == null) {
			singletonObject = new SingletonClass();
		}
		return singletonObject;
	}
	public Object clone() throws CloneNotSupportedException {
		throw new CloneNotSupportedException();
	}
}

public class SingletonObjectDemo {
 
	public static void main(String args[]) {
		//		SingletonClass obj = new SingletonClass();
                //Compilation error not allowed
		SingletonClass obj = SingletonClass.getSingletonObject();
		// Your Business Logic
		System.out.println("Singleton object obtained");
	}
}

On thing I can see right away is to get rid of the synchronization, as well as immediately initializing the singleton object (use a static initializer block, or just initialize it when you declare it). You're getter method can then simply return the singleton object without checking to see if it's null and creating the singleton object. This will allow multiple threads to retrieve the singleton object at the same time. However, there's no way for me to know how you're using that object which would say whether you can safely use that object in multiple threads at the same time.