Why can't Java constructors be synchronized?

Question

According to the Java Language Specification, constructors cannot be marked synchronized because other threads cannot see the object being created until the thread creating

Answer 1

The following code can achieve the expected result for synchronized constructor.

public class SynchronisedConstructor implements Runnable {

    private int myInt;

    /*synchronized*/ static {
        System.out.println("Within static block");
    }

    public SynchronisedConstructor(){
        super();
        synchronized(this){
            System.out.println("Within sync block in constructor");
            myInt = 3;
        }
    }

    @Override
    public void run() {
        print();
    }

    public synchronized void print() {
        System.out.println(Thread.currentThread().getName());
        System.out.println(myInt);
    }

    public static void main(String[] args) {

        SynchronisedConstructor sc = new SynchronisedConstructor();

        Thread t1 = new Thread(sc);
        t1.setName("t1");
        Thread t2 = new Thread(sc);
        t2.setName("t2");

        t1.start();
        t2.start();
    }
}