Not unless you want to write WeakThreadSafeDic<TKey,TVal> On Tue, Feb 3, 2009 at 1:17 PM, Fabio Maulo <[email protected]> wrote:
> NHibernate.Util.ThreadSafeDictionary<TKey, TValue> ? > > 2009/2/3 Ayende Rahien <[email protected]> > > That is a hack. >> The issue is still there, but just harder to hit. >> We have to either make WeakHashtable thread safe (probably very hard) or >> lock around setting/getting from it >> >> >> On Tue, Feb 3, 2009 at 12:05 PM, Pierre Henri Kuate <[email protected]>wrote: >> >>> >>> After further investigation, I think that here is how the issue >>> occurs: >>> >>> There is only one Worker per SessionFactory so multiple calls to >>> TransactionalWorker.PerformWork() can be running on different threads >>> at the same time. >>> The only line that changes the WeakHashtable is: >>> synchronizationPerTransaction[transaction] = txSync; >>> >>> Looking at its implementation, we can see that it scavenges first then >>> set the value. So if a scavenge is running on one thread while a set >>> is being performed on another, we get that exception. >>> >>> To test this theory, I modified the code like this: >>> synchronizationPerTransaction.SetWithoutScavenging(transaction, >>> txSync); // Which just set the value in the innerHashtable >>> And that exception hasn't occur after multiple tests. >>> >>> What do you think about this solution? Hack or Fix? :) >>> >>> Note that this require adding a method to >>> NHibernate.Util.WeakHashtable and I wonder if it doesn't reveal a >>> larger problem... >>> >>> >>> On Feb 3, 10:21 am, Ayende Rahien <[email protected]> wrote: >>> > looks like an obivious multi threading issue. I'll look into it a bit. >>> > >>> > On Tue, Feb 3, 2009 at 9:58 AM, Pierre Henri Kuate <[email protected] >>> >wrote: >>> > >>> > >>> > >>> > > Hi all, >>> > >>> > > I have access to a 8-core workstation and I use it to stress test my >>> > > project. >>> > > I noticed that the concurrency tests in NHibernate.Search sometimes >>> > > fail with the following exception: >>> > >>> > > System.InvalidOperationException: Collection was modified; >>> enumeration >>> > > operation may not execute. >>> > > at System.Collections.Hashtable.HashtableEnumerator.MoveNext() >>> > > at NHibernate.Util.WeakHashtable.Scavenge() in C:\Dev\NHibernate >>> > > \NHibernate\Util\WeakHashtable.cs:line 150 >>> > > at NHibernate.Util.WeakHashtable.set_Item(Object key, Object value) >>> > > in C:\Dev\NHibernate\NHibernate\Util\WeakHashtable.cs:line 198 >>> > > at NHibernate.Search.Backend.Impl.TransactionalWorker.PerformWork >>> > > (Work work, ISessionImplementor session) in C:\Dev\NHibernate >>> > > \NHibernate.Search\Backend\Impl\TransactionalWorker.cs:line 28 >>> > > at NHibernate.Search.Event.FullTextIndexEventListener.ProcessWork >>> > > (Object entity, Object id, WorkType workType, AbstractEvent e) in C: >>> > > \Dev\NHibernate\NHibernate.Search\Event >>> > > \FullTextIndexEventListener.cs:line 54 >>> > > at NHibernate.Search.Event.FullTextIndexEventListener.OnPostUpdate >>> > > (PostUpdateEvent e) in C:\Dev\NHibernate\NHibernate.Search\Event >>> > > \FullTextIndexEventListener.cs:line 94 >>> > > at NHibernate.Action.EntityUpdateAction.PostUpdate() in C:\Dev >>> > > \NHibernate\NHibernate\Action\EntityUpdateAction.cs:line 172 >>> > > at NHibernate.Action.EntityUpdateAction.Execute() in C:\Dev >>> > > \NHibernate\NHibernate\Action\EntityUpdateAction.cs:line 128 >>> > > at NHibernate.Engine.ActionQueue.Execute(IExecutable executable) in >>> > > C:\Dev\NHibernate\NHibernate\Engine\ActionQueue.cs:line 130 >>> > > at NHibernate.Engine.ActionQueue.ExecuteActions(IList list) in C: >>> > > \Dev\NHibernate\NHibernate\Engine\ActionQueue.cs:line 113 >>> > > at NHibernate.Engine.ActionQueue.ExecuteActions() in C:\Dev >>> > > \NHibernate\NHibernate\Engine\ActionQueue.cs:line 147 >>> > > at >>> > > >>> NHibernate.Event.Default.AbstractFlushingEventListener.PerformExecutions >>> > > (IEventSource session) in C:\Dev\NHibernate\NHibernate\Event\Default >>> > > \AbstractFlushingEventListener.cs:line 241 >>> > > at NHibernate.Event.Default.DefaultFlushEventListener.OnFlush >>> > > (FlushEvent event) in C:\Dev\NHibernate\NHibernate\Event\Default >>> > > \DefaultFlushEventListener.cs:line 19 >>> > > at NHibernate.Impl.SessionImpl.Flush() in C:\Dev\NHibernate >>> > > \NHibernate\Impl\SessionImpl.cs:line 1215 >>> > > at NHibernate.Transaction.AdoTransaction.Commit() in C:\Dev >>> > > \NHibernate\NHibernate\Transaction\AdoTransaction.cs:line 177 >>> > > at NHibernate.Search.Tests.Worker.WorkerTestCase.ReverseWork(Object >>> > > state) in C:\Dev\NHibernate\NHibernate.Search.Tests\Worker >>> > > \WorkerTestCase.cs:line 216 >>> > >>> > > Note that it also occurs on my Core 2 Duo, but far less often. >>> > >>> > > Have you ever experienced this issue? Any suggestions on how to fix >>> it? >>> >>> >> >> >> > > > -- > Fabio Maulo > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "NHibernate Contrib - Development Group" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com.ar/group/nhcdevs?hl=en -~----------~----~----~----~------~----~------~--~---
