Microbenchmark for Bridge vs reflection vs direct access

tunah (Sam McCall) — Wed, 21 Nov 2007 11:51:06 GMT
import java.lang.reflect.Method;



public class TimingTest {

	public interface IFoo { public void foo(); }

	public interface PubFoo { public void foo(); }

	public static class Impl implements PubFoo { public void foo(){} }



	static final int COUNT = 10000000;

	public static void main(String[] args) throws Exception {

		Impl impl = new Impl();

		int count;



		startTiming("Bridge (including BCEL)");

		IFoo ifoo = Bridge.expose(impl, IFoo.class);

		stopTiming();

		startTiming("Bridge (BCEL loaded)");

		Bridge.expose(impl, PubFoo.class);

		stopTiming();



		System.out.println(COUNT+" virtual invocations, warm");



		startTiming("Direct");

		for(int i=0; i			impl.foo();

		stopTiming();



		Method m = impl.getClass().getMethod("foo",new Class[0]);

		startTiming("Reflection");

		for(int i=0; i			m.invoke(impl);

		stopTiming();



		startTiming("Bridge");

		for(int i=0; i			ifoo.foo();

		stopTiming();





		System.out.println("1 virtual invocation on "+COUNT+" objects");



		startTiming("Direct");

		for(int i=0; i			impl.foo();

		stopTiming();



		startTiming("Reflection");

		Method tmpM = null;

		Class[] no_args = new Class[0];

		for(int i=0; i			if(tmpM == null || tmpM.getDeclaringClass() != impl.getClass())

				tmpM = impl.getClass().getMethod("foo",no_args);

			tmpM.invoke(impl);

		}

		stopTiming();



		startTiming("Bridge");

		for(int i=0; i			IFoo temp = Bridge.expose(impl, IFoo.class);

		}

		stopTiming();



		

		System.out.println(COUNT+" interface invocations, warm");

		PubFoo pfoo = (PubFoo)impl;

		Method mi = impl.getClass().getInterfaces()[0].getMethod("foo", new Class[]{});

		IFoo iifoo = Bridge.expose(impl, PubFoo.class, IFoo.class);



		startTiming("Direct");

		for(int i=0; i			pfoo.foo();

		stopTiming();



		startTiming("Reflection");

		for(int i=0; i			mi.invoke(impl);

		stopTiming();



		startTiming("Bridge");

		for(int i=0; i			iifoo.foo();

		stopTiming();

		

	}

	static long timer;

	static void startTiming(String task) {

		System.out.printf("  * %12s - ", task);

		System.out.flush();

		timer = System.currentTimeMillis();

	}

	static void stopTiming() {

		long time = System.currentTimeMillis() - timer;

		System.out.println(time+" ms");

	}

}
DZone Snippets: benchmark code

Microbenchmark for Bridge vs reflection vs direct access
