Re: Patch to Throwable and StackTraceElement (reduced CPU usage)

[Mike Skells]

Doh,
This time with the patches, test code, and CPU usage stats attached

Regard

Mike 



>________________________________
>From: Alan Bateman <alan.bate...@oracle.com>
>To: mike.ske...@talk21.com
>Cc: Core-Libs-Dev <core-libs-dev@openjdk.java.net>
>Sent: Monday, 10 October 2011, 0:15
>Subject: Re: Patch to Throwable and StackTraceElement (reduced CPU usage)
>
>mike.ske...@talk21.com wrote:
>> :
>>
>>
>> I include the patch, a micro-benchmark and the results of the 
>> micro-benchmark which show an improvement of 80% throughput (ie it is almost 
>> twice as fast)
>>  
>Mike - I don't think there is a patch attached to your mail.
>
>
>
/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package compare;

import java.io.PrintWriter;
import java.io.StringWriter;

/**
 *
 * @author mike
 */
public class TestThrow {

    public static void main(String[] args) throws InterruptedException {
        try {
            generateThrow1(5);
        } catch (Throwable t) {
            int count = 100;
            StringWriter sw = new StringWriter(20000);
            PrintWriter pw = new PrintWriter(sw);

            System.out.println(sw);
            for (int j = 0; j < 100; j++) {
                long total = 0;
                for (int i = 0; i < count; i++) {
                    sw.getBuffer().setLength(0);
                    long start = System.nanoTime();
                    t.printStackTrace(pw);
                    long end = System.nanoTime();
                    total += end - start;
                }
                System.out.println((total / count));
                
            }



        }
    }

    private static void generateThrow1(int depth) {
        generateThrow2(depth);
    }

    private static void generateThrow2(int depth) {
        generateThrow3(depth);
    }

    private static void generateThrow3(int depth) {
        generateThrow4(depth);
    }

    private static void generateThrow4(int depth) {
        generateThrow5(depth);
    }

    private static void generateThrow5(int depth) {
        if (depth == 0) {
            throw new RuntimeException("some text ..." + depth);
        } else {
            try {
                generateThrow1(depth - 1);
            } catch (RuntimeException x) {
                throw new RuntimeException("some text ..." + depth, x);
            }
        }
    }
}