nx:All of URLy Bird 1.1.3 about multiple thread test

[liqun chang]

Hi George:I am a chinese.and can not get Max'book.So only use you multiple thread test code.
I use the code that your provide.but when i test 300 threads,the owner field not same.part of thread throws security exception,another part do not
throw security exception.Why? could you help me?

[liqun chang]

Hi George:where did you go? as above mention,i test 300 threads,but the results of Owner fields is not same,also between 1800~1860,if my Random.nextLong() don't create unique value? In which situation can result in this result?please you help me?

[liqun chang]

Hi George,as you can see.

package test;
import test.*;
import javax.swing.*;
import java.io.*;
import suncertify.db.*;
class Update extends Thread
{
Data data;
int thread;
int count;
int recNo;
File file;
int id;

public Update(int t,int c,int r,File file)
{
thread=t;
count=c;
recNo=r;

data=new Data(file);

}
public void run()
{
for(int i=0;i<count;i++)
{
try
{
String name=thread+" : "+i+" : "+recNo;
long cookie=data.lock(recNo);
System.out.println(name+" record lock");
String[] fields=data.read(recNo);
System.out.println(name+" record read");
try
{

id=Integer.parseInt(fields[6].trim());

      }
catch(NumberFormatException ne){System.out.println("********");}
id++;
fields[6]=""+id;
data.update(recNo,fields,cookie);
System.out.println(name+"update");
data.unlock(recNo,cookie);
System.out.println(name+"unlock");
}

catch(Exception e)
{
System.err.println(e.getMessage());
e.printStackTrace(System.err);
}
}
}
}

public class testMutipleUpdate
{
File file;
public static void main(String args[])
{
new testMutipleUpdate();
}

public testMutipleUpdate()
{
JFileChooser fileChooser=new JFileChooser();
fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
int result=fileChooser.showOpenDialog(null);
if(result==JFileChooser.CANCEL_OPTION)
return;
file=fileChooser.getSelectedFile();

Update[][] tests=new Update[10][];
for(int i=0;i<tests.length;i++)
{
tests[i]=new Update[30];

for(int j=0;j<tests[i].length;j++)
{
tests[i][j]=new Update(j,200,j+1,file);
//public Update(int t,int c,int r,File file)
}

try
{
for(int j=0;j<tests[i].length;j++)
{
Thread.currentThread().sleep(100);
tests[i][j].start();
}
}
catch(InterruptedException ie)
{
}

}
System.out.println("complete all test");
}
}


  

From this test,i finally get the result of owner field,but they are not
2000,but from 1800~1860,and the stack trace display the security exception
? why can result in this situation?