// File Reflect4.java 

// The reflective call is 50 to 120 times slower than a virtual call.

import java.lang.reflect.*;                             // Method

class Reflect4 {
  public static void main(String[] args) 
    throws NoSuchMethodException, IllegalAccessException, 
           InvocationTargetException {
    int count = Integer.parseInt(args[0]);
    Class ty = SomeClass.class;                         // Get SomeClass class
    Method m = ty.getMethod("m", new Class[] {});       // Get m() method
    SomeClass o = new SomeClass();
    Object[] margs = new Object[] { };
    Timer t1 = new Timer();
    for (int i=count; i>0; i--)
      m.invoke(o, margs); 
    System.out.println("Reflective call to o.m: " + t1.Check());
    System.out.println(o.k);
    Timer t2 = new Timer();
    for (int i=count; i>0; i--)
      o.m(); 
    System.out.println("Virtual call to o.m: " + t2.Check());
    System.out.println(o.k);
    SomeClassInterface oi = o;
    Timer t3 = new Timer();
    for (int i=count; i>0; i--)
      oi.m(); 
    System.out.println("Interface call to oi.m: " + t3.Check());
    System.out.println(oi.getK());

  }
}

class SomeClass implements SomeClassInterface {
  public int k = 1;

  public void m() {
    if (k > 0)
      k++;
    else { // Some dummy code with a recursive call to prevent inlining
      for (int j=k; j<=0; j++) {
        k++;
        m();
      }
    }
  }

  public int getK() { return k; }
}

interface SomeClassInterface {
  public void m();
  public int getK();
}

// Crude timing utility ----------------------------------------
   
class Timer {
  private long start;

  public Timer() {
    start = System.currentTimeMillis();
  }

  public double Check() {
    return (System.currentTimeMillis()-start)/1000.0;
  }
}