code: protected void set(V v) {
          if (U.compareAndSwapInt(this, STATE, NEW, COMPLETING)) {
              outcome = v;
              U.putOrderedInt(this, STATE, NORMAL); // final state
              finishCompletion();
          }
      }
docs: Sets the result of this future to the given value unless
  this future has already been set or has been cancelled.
  
  <p>This method is invoked internally by the {@link #run} method
  upon successful completion of the computation.
  
  @param v the value