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multithreadingnhibernatethread-safetycastle-windsorcastle

Thread safe issue with Castle.Facilities.NHibernateIntegration ISessionManager in Web context


So based on this question (here), of which I asked last week, I decided to go and have a look into the Castle project and use the Castle.Facilities.NHibernateIntegration facility.

I spent the best part of two days messing around with it and have come to the same issue: NHibernate Thread-Safe Sessions. I was hoping, out of the box, the built in ISessionManager was smart enough to handle threading, which is the reason why I decided to implement it.

In the very sparse documentation on that particular project it mentions that calling ISessionManager.OpenSession is much the same as calling session.GetCurrentSession. From this I gather there is no way for me to, force open, a new seperate session.

So has anyone the solution for me or any ideas how I can work with this issue?

(I know most people are going to say only work with one thread, but honestly think outside the box, some tools and routines automatically spawn a new thread. For instance, log4net and sessionstatestore. You can't just assume there will only be one thread, associated, with the current request.)

Notes:

  • I'm working on the web model with .NET 4 web application.

  • I invoke and resolve the Windsor container in the usual, documented way and let the container resolve the session manager. I do this in both threads.

  • Here is my Castle NHibernate config:

Code:

<facility id="nhibernate" isWeb="true" type="Castle.Facilities.NHibernateIntegration.NHibernateFacility, Castle.Facilities.NHibernateIntegration">
  <factory id="nhibernate.factory">
    <settings>
      <item key="connection.connection_string">#{NHibernateConnectionString}</item>
      <item key="connection.driver_class">#{NHibernateDriver}</item>
      <item key="connection.provider">NHibernate.Connection.DriverConnectionProvider</item>
      <item key="dialect">#{NHibernateDialect}</item>
      <item key="generate_statistics">true</item>
      <item key="proxyfactory.factory_class">NHibernate.ByteCode.Castle.ProxyFactoryFactory, NHibernate.ByteCode.Castle</item>
      <item key="show_sql">true</item>
    </settings>
    <assemblies>
      <assembly>Gigastence.Base.Common</assembly>
    </assemblies>
  </factory>
  • Here is my example DAO

Code:

public class NHibernateDao : INHibernateDao
{
    private ISessionManager sessionManager;

    public NHibernateDao(ISessionManager sessionManager)
    {
        this.sessionManager = sessionManager;
    }

    public void Append(LoggingEvent loggingEvent)
    {
        using (IStatelessSession session = sessionManager.OpenStatelessSession())
        {
            using (ITransaction tran = session.BeginTransaction())
            {
                Log data = new Log
                {
                    Id = Guid.NewGuid(),
                    Date = loggingEvent.TimeStamp,
                    Level = loggingEvent.Level.ToString(),
                    Logger = loggingEvent.LoggerName,
                    Thread = loggingEvent.ThreadName,
                    Message = loggingEvent.MessageObject.ToString()
                };

                if (loggingEvent.ExceptionObject != null)
                {
                    data.Exception = loggingEvent.ExceptionObject.ToString();
                }

                session.Insert(data);
                tran.Commit();
            }
        }
    }
}
  • And how I call the DAO. Note: This is on the newly spawned thread which is out of my hands.

Code:

public class NHibenateAppender : AppenderSkeleton
{
    protected override void Append(LoggingEvent loggingEvent)
    {
        if(IoC.IsInitialized)
        {
            var NHibernateLogger = IoC.Resolve<INHibernateDao>();
            NHibernateLogger.Append(loggingEvent);
        }
    }
}

Solution

  • If you want full control of the session, I believe that the NHibernateFacility actually registers the underlying ISessionFactory to the Windsor kernel.

    From that, you can invoke sessionFactory.OpenSession() which I think should always return a new session.

    I honestly don't really see what ISessionManager brings to the party...