[Helma-user] java.util.ConcurrentModificationException on app.addRepository

[Bernhard Fröhlich]

> Hello list,
>
> we load our widgets on helma start with app.addRepository and sometimes we
> get the following error code:
>
> ...
> [2008/07/17 11:19:23] [INFO] START INFO load widgets [Application
> twoday_w1_s2]
> [2008/07/17 11:19:23] [INFO] ---- adding repository
> C:\helma-1.6.2\apps\twoday_w1_1_1\core\widgets\amazon\code
> [2008/07/17 11:19:23] [ERROR] null:
> java.util.ConcurrentModificationException
> java.util.ConcurrentModificationException
>         at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793)
>         at java.util.HashMap$ValueIterator.next(HashMap.java:821)
>         at
> helma.framework.core.TypeManager.checkRepositories(TypeManager.java:204)
>         at
> helma.framework.core.TypeManager.checkPrototypes(TypeManager.java:124)
>         at
> helma.scripting.rhino.RhinoCore.updatePrototypes(RhinoCore.java:330)
>         at
> helma.scripting.rhino.RhinoEngine.enterContext(RhinoEngine.java:174)
>         at
> helma.framework.core.RequestEvaluator.run(RequestEvaluator.java:172)
>         at java.lang.Thread.run(Thread.java:619)
> [2008/07/17 11:19:23] [INFO] ---- adding repository
> C:\helma-1.6.2\apps\twoday_w1_1_1\core\widgets\archive\code
> [2008/07/17 11:19:23] [INFO] ---- adding repository
> C:\helma-1.6.2\apps\twoday_w1_1_1\core\widgets\credits\code
> ...
> the error is reproduceable on some machines (windows, linux) under
> helma1.6.0 and helma 1.6.2, java1.6.0_01 and java1.6.0_06. it seems to be
> a
> racing condition?


I am not familiar with the Helma code but as far as i can tell there seems
to be a missing synchronisation in TypeManager.java:checkRepositories()
because the Iterator is not protected from getting invalid.

So it seems like an helma bug - would you mind creating an bugreport?

Bernhard Fröhlich