Test Your Effective Locking Mechanism by Threads

[Sudhansu Pati]

Hi all,
I am not sure how you guys are testing your locking strategy. I have used the followed testing program. May be you should use it. Because I had to go back and change my code a lot during testing.
Create1

<font size="2">
public class Create1 implements Runnable{
  Data d = new Data();
  public void run() {
    String [] s = {"Valid", "Create1", "saint Louis", "Manager", "9", "$400", ""};
      try {
        d.create(s);
      }
      catch (DuplicateKeyException ex) {
        ex.printStackTrace();
      }
  }
</font>

Create2

<font size="2">
public class Create2 implements Runnable{
  Data d = new Data();
  public void run() {
    String [] s = {"Valid", "Create2", "saint Louis", "Manager", "9", "$400", ""};
      try {
        d.create(s);
      }
      catch (DuplicateKeyException ex) {
        ex.printStackTrace();
      }
  }
</font>

Delete1

<font size="2">
public class Delete1 implements Runnable{
  Data d = new Data();
  int recNo = 0;
  public Delete1(int _recNo){
    recNo= _recNo;
  }
  public void run() {
    try {
      long lockCookie = d.lock(recNo);
      d.delete(recNo, lockCookie);
      d.unlock(recNo, lockCookie);
    }
    catch (SecurityException ex) {
      ex.printStackTrace();
    }
    catch (RecordNotFoundException ex) {
      ex.printStackTrace();
    }
  }
</font>

Delete2

public class Delete2 implements Runnable{
  Data d = new Data();
  int recNo = 0;
  public Delete2(int _recNo){
    recNo= _recNo;
  }
  public void run() {
    try {
      long lockCookie = d.lock(recNo);
      d.delete(recNo, lockCookie);
      d.unlock(recNo, lockCookie);
    }
    catch (SecurityException ex) {
      ex.printStackTrace();
    }
    catch (RecordNotFoundException ex) {
      ex.printStackTrace();
    }
  }

Update1

<font size="2">
public class Update1 implements Runnable{
  private static Data d = new Data();
  int recNo = 0;
  public Update1(int _recNo){
  recNo = _recNo;
  }
  public void run() {
    String [] s = { "Update1", "Cupertino", "CEO", "9", "$2000", ""};
    try {
      long lockCookie = d.lock(recNo);
      d.update(recNo, s, lockCookie);
      d.unlock(recNo, lockCookie);
    }
    catch (SecurityException ex) {
      ex.printStackTrace();
    }
    catch (RecordNotFoundException ex) {
      ex.printStackTrace();
    }
  }
}
</font>

Update2

<font size="2">
public class Update2 implements Runnable{
  private static Data d = new Data();
  int recNo = 0;
  public Update1(int _recNo){
  recNo = _recNo;
  }
  public void run() {
    String [] s = { "Update2", "Cupertino", "CEO", "9", "$2000", ""};
    try {
      long lockCookie = d.lock(recNo);
      d.update(recNo, s, lockCookie);
      d.unlock(recNo, lockCookie);
    }
    catch (SecurityException ex) {
      ex.printStackTrace();
    }
    catch (RecordNotFoundException ex) {
      ex.printStackTrace();
    }
  }
}
</font>

DataTest

<font size="2">
public class DataTest {
  public DataTest() {
  }
  public static void main(String[] args) {
    DataHelper dbHelper = new DataHelper();
    Data data = new Data();
    int recNo1= 35;
    Update1 u1 = new Update1(recNo1);
    Update2 u2 = new Update2(recNo1);
    Thread tu1 = new Thread(u1,"u1");
    Thread tu2 = new Thread(u2,"u2");
    Delete1 d1 = new Delete1(recNo1);
    Delete2 d2 = new Delete2(recNo1);
    Thread td1 = new Thread(d1,"d1");
    Thread td2 = new Thread(d2,"d2");
    tu2.start();
    tu1.start();
    td1.start();
    td2.start();
     Create1 c1 = new Create1();
     Create2 c2 = new Create2();
    Thread tc1 = new Thread(c1,"c1");
    Thread tc2 = new Thread(c2,"c2");
    tc1.start();
    tc2.start();
}
</font>

I think this code posting is ok, because this is outside of the assignment. But I found this very useful and you may too. If you have followed different testting strategy, post your code here.
[ October 05, 2003: Message edited by: Suds Pati ]

[Chris Harris]

Hi Suds,
I am planning to test me code using JUnit. I am only at the start of the project so I don't currently have any thing useful to show you.
You may want to look it up at :JUnit
Hope you find it useful
Chris

[Andrew Monkhouse]

Hi Suds,
Do you go back and manually verify that the database is OK after these tests?
I am guessing that you should see a few stack traces when you run this. Is that correct?
Chris did make a good suggestion with JUnit - it is very good, and a lot of businesses use it. Working on this assignment is a good time to learn how to use it yourself.
Regards, Andrew

[Sudhansu Pati]

Hi Andrew, Chris,

I am familiar with JUnit. Also I am using JBuilder which allows me to create TestCases, Test Suites on fly. JUnut will help you on functional testing. Every method can be tested with JUnit to see if the methods are returning the right value. But how would you test for deadlock, thread contention and livelock ? Can JUnit help me creating concurrent threads ?
Well, I have OptimizeIt Thread Debugger which will help me finding thread contention, dealdlock and livelock. But I have left the heavy use of tools for testing towards the end of the project.
How do I know my database status after the testing. I periodically display the entire database content in JBuilder. Also I monitor the exceptions and outputs (System.out.println()). Sometimes I use the JBuilder debugger.
Regards,
Suds

[Sakke Wiik]

But how would you test for deadlock, thread contention and livelock ? Can JUnit help me creating concurrent threads ?

Read this document, it explains how to use GroboUtils(http://groboutils.sourceforge.net/) for testing threads with JUnit: http://today.java.net/pub/a/today/2003/08/06/multithreadedTests.html
It also has basic dead-lock support using timers.

How do I know my database status after the testing.

Just re-read the databasefile and match it against the original. Or you could have the original stored as a static variable somewhere (or a more complex object if you for example read the databasefile into objects).
I have a BaseTest-class which I extend in my testclasses instead of TestCase, in which setUp-method I simply copy the original databasefile to a test-directory. This way each test works against a newly copied original databasefile, and after tests I could match the files if I need.
cheers,
Sakke