Are Dynamic Finds Thread Safe?

Hi,

Hope someone can help here.

I'm running a scheduled app to process multiple databases at once. It's designed to be multithreading and for the most part it works fine.

The problem is that every so often I get the following error when processing one of the databases;

System.ApplicationException: cannot find the query 'dbo.TransferBids_Find_Dynamic' in the embedded xml file.

   at FootballPro.Data.WorldDatabase.Data.SqlClient.StoredProcedureProvider.GetProcedureBodyFromEmbeddedResource(String name) in [SNIP]WorldDatabase.Data.SqlClient\StoredProcedureProvider.cs:line 161

This only seems to occour when processing the databases using threads, if they're processed consecutively then the error doesn't appear.

The code causing it is;

TransferBidsService bidsService = new TransferBidsService();
TransferBidsParameterBuilder tbParamBuilder = new TransferBidsParameterBuilder();
tbParamBuilder.AppendEquals(TransferBidsColumn.Status, ((int)TRANSFERBIDSTATUS.TBS_PENDING).ToString());
tbParamBuilder.AppendEquals(TransferBidsColumn.PlayerId, Data.PlayerId.ToString());
TList<TransferBids> outstandingBids = bidsService.Find(tbParamBuilder);

does anyone have any ideas?

cheers, Iain

What version of the templates are you using (check changes.log)?  I thought that this was resolved in one of the more recent builds.

.netTiers v2.2.0.603

The full exception stack trace is:

System.ApplicationException: cannot find the query 'dbo.TransferBids_Find_Dynamic' in the embedded xml file.

   at SqlClient.StoredProcedureProvider.GetProcedureBodyFromEmbeddedResource(String name) in SqlClient\StoredProcedureProvider.cs:line 161

   at SqlClient.StoredProcedureProvider.GetCommandWrapper(Database database, String commandName, Type columnEnum, SqlFilterParameterCollection parameters, String orderBy, Int32 start, Int32 pageLength) in SqlClient\StoredProcedureProvider.cs:line 204

   at SqlClient.SqlTransferBidsProviderBase.Find(TransactionManager transactionManager, IFilterParameterCollection parameters, String orderBy, Int32 start, Int32 pageLength, Int32& count) in SqlClient\SqlTransferBidsProviderBase.generated.cs:line 324

   at Services.TransferBidsServiceBase.Find(IFilterParameterCollection parameters, String orderBy, Int32 start, Int32 pageLength, Int32& count) in Services\TransferBidsServiceBase.generated.cs:line 547

   at Services.TransferBidsServiceBase.Find(IFilterParameterCollection parameters, String orderBy) in Services\TransferBidsServiceBase.generated.cs:line 508

   at Services.TransferBidsServiceBase.Find(IFilterParameterCollection parameters) in Services\TransferBidsServiceBase.generated.cs:line 496

If that's any help?

I've trimmed the full filenames for clarity

cheers, Iain

Oy....  It looks like the StoredProcedureProvider is not thread safe, even though some attempts have been made to make it so.  Unfortunately, my knowledge of threading and locking issues is pretty scarce, so I don't know how to fix the issue.  Perhaps someone with more threading knowledge can step up and take a look at this class and provide some direction.

Bah, there goes my hope for an easy fix

 Well, thanks for your help.

 Does anyone know how to fix that?

cheers,
Iain

Try the patch attached to this post, i think it is caused by the lack of a lock on the indexer property, this simple patch just ensures the hashtables are initialized fully before being accessed.  Please let us know if this fixes your issue, so that it may be incorporated into the release by the .netTiers team. 

Thanks mate, that seems to have sorted it.

 I'll keep you posted if it happens again.

cheers,
Iain

Added as SVN663.

hth 

swin