Re: [j-devel] Checking arg types without setting up a try/except block

[<log...@gm...>]

package error_handler_benchmark;

public class BenchCatchThrow {

 static int coolDown;

 static void type_error_handler(BaseObject obj) {
  // cooldown; required so its not eliminated by JIT
  coolDown++;
 }

 static class BaseObject {
  public long longValue() {
   type_error_handler(this);
   return 0;
  }
 }

 static class RightObject extends BaseObject {
  public final long value = 666;

  @Override
  public long longValue() {
   return value;
  }
 }

 static class WrongObject extends BaseObject {
 }

 public static void main(String[] args) throws Exception {
  System.out.println("java.vm.vendor "
    + System.getProperty("java.vm.vendor"));
  System.out
    .println("java.version " + System.getProperty("java.version"));
  System.out.println("java.vm.version "
    + System.getProperty("java.vm.version"));
  for (int i = 1; i <= 10; i++) {
   System.out.println();
   System.out.println("Run " + i);
   mainBench();
  }
 }

 public static void mainBench() throws Exception {
  long m1Time = 0;
  long m2Time = 0;
  long m3Time = 0;
  for (int i = 0; i < 10; i++) {
   coolDown = 0;
   m1Time += benchM1();
   coolDown = 0;
   m2Time += benchM2();
   coolDown = 0;
   m3Time += benchM3();
  }
  System.out.println("Exception catching time = " + m1Time + "ms");
  System.out.println("Exception avoiding time = " + m3Time + "ms");
  System.out.println("Deterministic call time = " + m2Time + "ms");
  System.out.println("% = " + ((double) m2Time / (double) m1Time) * 100);
 }

 static BaseObject GOOD = new RightObject();
 static BaseObject BAD = new WrongObject();

 static final int ITERATIONS = 100000;

 private static long benchM1() {

  long start = System.currentTimeMillis();
  long count = 0;
  for (int i = ITERATIONS; i > 0; i--) {
   BaseObject arg = i % 2 == 0 ? GOOD : BAD;
   try {
    count += ((RightObject) arg).value;
   } catch (ClassCastException cce) {
    type_error_handler(arg);
   }
  }
  long end = System.currentTimeMillis();
  return (end - start);
 }

 private static long benchM2() {

  long start = System.currentTimeMillis();
  int count = 0;
  for (int i = ITERATIONS; i > 0; i--) {
   BaseObject arg = i % 2 == 0 ? GOOD : BAD;
   count += arg.longValue();
  }
  long end = System.currentTimeMillis();
  return (end - start);
 }


 private static long benchM3() {

  long start = System.currentTimeMillis();
  int count = 0;
  for (int i = ITERATIONS; i > 0; i--) {
   BaseObject arg = i % 2 == 0 ? GOOD : BAD;
    if (arg instanceof RightObject) count += ((RightObject) arg).value;
    else type_error_handler(arg);
  }
  long end = System.currentTimeMillis();
  return (end - start);
 }
}


OUTPUT:

java.vm.vendor Sun Microsystems Inc.
java.version 1.6.0_10
java.vm.version 11.0-b15

Run 1
Exception catching time = 5821ms
Exception avoiding time = 9ms
Deterministic call time = 5ms
% = 0.08589589417625838

Run 2
Exception catching time = 5413ms
Exception avoiding time = 3ms
Deterministic call time = 2ms
% = 0.03694808793644929

Run 3
Exception catching time = 5568ms
Exception avoiding time = 2ms
Deterministic call time = 4ms
% = 0.07183908045977011

Run 4
Exception catching time = 5464ms
Exception avoiding time = 3ms
Deterministic call time = 1ms
% = 0.018301610541727673

Run 5
Exception catching time = 5480ms
Exception avoiding time = 5ms
Deterministic call time = 3ms
% = 0.05474452554744526

Run 6
Exception catching time = 5626ms
Exception avoiding time = 3ms
Deterministic call time = 5ms
% = 0.08887308922858159

Run 7
Exception catching time = 5638ms
Exception avoiding time = 2ms
Deterministic call time = 1ms
% = 0.0177367860943597

Run 8
Exception catching time = 5579ms
Exception avoiding time = 3ms
Deterministic call time = 2ms
% = 0.0358487184083169

Run 9
Exception catching time = 5603ms
Exception avoiding time = 3ms
Deterministic call time = 2ms
% = 0.03569516330537212

Run 10
Exception catching time = 5434ms
Exception avoiding time = 5ms
Deterministic call time = 1ms
% = 0.01840264998159735