Issue in singleton class

In reply to Ashwath Saralaya:

So if obj_singleton is not null, create method will return nothing?
You should change your code like this:

    static function singleton create ();
        if (obj_singleton == null)begin
            obj_singleton = new();
            $display("Creating object ");
        end
        else begin
            $display("Already object exists");
        end
        return obj_singleton;
    endfunction

By the way, in singleton pattern, both obj_singleton in your code and new() function MUST be declared as a local variable, otherwise, your obj_singleton can be changed easily.