Name: boT120536			Date: 03/16/2001


fog1: {9} % java -version
java version "1.3.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0)
Java HotSpot(TM) Client VM (build 1.3.0, mixed mode)

When I insert URLs into a Map is runs VERY!!! slowly, yet uses no CPU.
When I insert URLs with the same Host, is runs fast, and no problem.
When the URLs have different Hosts, the bug occurs.
URL is final class, so I couldn't subclass from it to try and work around it, 
by changing the hash funtion, etc.

I've already tried setting the loadfactor to .5 and setting the initial
capacity to like 10000.  And I've tried setting it small.  It barely get to
10 or 15 URLs and has problems.  The performance it very bursty, like it
does 5 and then hangs, then does 10 and hangs, then 2 and hangs.   For
example, in 10 min, I only was able to put 653 URLs into the map.  VERY bad
performance.

I thought at first it was a hashing problem (too many hashings going on),
but if that were the case, the CPU should be stressed.  CPU is virtually 0.

I've tried increasing threads priority, with little effect.

I'm running on a Dual 666MHz PIII, 256MB ram with Linux.  Same thing on win2k.


Code that causes the problem:
import java.lang.*;
import java.util.*;
import java.net.*;
import java.io.*;

public class h{
    public static void main(String[] args){
	//This CODE goes very slow!!!!  But the CPU is not in used, so probably a locking problem
        try{
	    Map m_TrackedLinks = new HashMap();
	    int count = 0;
            while(true){
		Integer I = new Integer(count++);
		URL url = new URL("http://www.a" + I.toString() + ".com/" +I.toString());
                m_TrackedLinks.put(url, "Hello world");
		System.out.println("Adding url: " + url.toString());
            }
	    
        }
        catch(Exception e){System.out.println("Had a problems");}
    }
}

Same code, but this time with the same Host.  It works really fast.
import java.lang.*;
import java.util.*;
import java.net.*;
import java.io.*;

public class g{
    public static void main(String[] args){
        try{
	    Map m_TrackedLinks = new HashMap();
	    int count = 0;
            while(true){
		Integer I = new Integer(count++);
		URL url = new URL("http://www.a.com/" + I.toString());
                m_TrackedLinks.put(url, "Hello world");
		System.out.println("Adding url: " + url.toString());
            }
	    
        }
        catch(Exception e){System.out.println("Had a problems");}
    }
}
(Review ID: 118970) 
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