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From Craig L Russell <Craig.Russ...@SUN.com>
Subject Re: refresh()
Date Wed, 02 May 2007 08:27:38 GMT
Hi Christiaan,

On May 2, 2007, at 12:54 AM, Christiaan des Bouvrie wrote:

> "// get fresh instances from the datastore
> pm.getDataStoreCache().evictAll(collection);
> pm.refresh(collection);"
>
> That was indeed my initial approach. Unfortunately the evictAll()
> nullifies references in the pc objects which caused
> nullpointerexceptions in our multi-threaded application (multi- 
> threaded
> option is set to true).

This sounds like a bug in the jdo implementation. The use of evictAll  
should never cause side effects other than performance. That is, when  
you evict instances from the DataStoreCache, the effect is that  
access to the evicted instance must use the connection to the  
datastore instead of using the cached instance.

In fact, the use of the Multithreaded flag is intended to make your  
application run correctly with multiple threads using the same  
PersistenceManager at the expense of running slower.

Multithreaded access to the PersistenceManagerFactory and  
DataStoreCache is always thread-safe. Note that access to the  
DataStoreCache is not related to PersistenceManager but  
PersistenceManagerFactory.

Regards,

Craig
>
>
>
> Kind regards,
>
> Christiaan
>

Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:Craig.Russell@sun.com
P.S. A good JDO? O, Gasp!


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