多线程 – 将SharpArchitecture的NHibernateSession与不同的线程

protected void Application_BeginRequest(object sender,EventArgs e)
    {
        NHibernateInitializer.Instance().InitializeNHibernateOnce(InitializeNHibernateSession);
    }

    private void InitializeNHibernateSession(ISessionStorage sessionStorage)
    {
        NHibernateSession.ConfigurationCache = new NHibernateConfigurationFileCache(
            new[] { "App.Core" });
        NHibernateSession.Init(
            sessionStorage,new[] { Server.MapPath("~/bin/" + ApplicationSettings.Instance.NHibernateMappingAssembly) },new AutoPersistenceModelGenerator().Generate(),Server.MapPath("~/NHibernate.config"));

        NHibernateSession.AddConfiguration(ApplicationSettings.NHIBERNATE_OTHER_DB,Server.MapPath("~/NHibernateForOtherDb.config"),null,null);
    }

protected void Application_Start()
    {
            ....
            ThreadingManager.Instance.ExecuteAction(() =>
            {
                // initialize another NHibernateSession within SharpArchitecture somehow
                NHibernateInitializer.Instance().InitializeNHibernateOnce(InitializeNHibernateSession);

                var service = container.Resolve<IDatabaseSynchronizationService>();
                service.SynchronizeRepositories();
            });
}

我假设sessionStorage是一个SharpArch.Web.NHibernate.WebSessionStorage对象,对吧？如果是这样那么问题不在于NHibernate会话是空的,它可能在你的线程上,HttpContext.Current为null,并且WebSessionStorage对象依赖于HttpContext.Current来完成它的工作(见 this code,特别是第37行),其中,当从线程调用时,context为null,因此发生null异常).

我认为解决方案是编写一个不同的SessionStorage对象,检查HttpContext.Current是否为null,如果是,则使用线程本地存储来存储NHibernate会话(这个解决方案是从其他StackOverflow文章中讨论的同样的事情：NullReferenceException when initializing NServiceBus within web application Application_Start method)

编辑

也许这样的东西：

public class HybridWebSessionStorage : ISessionStorage
{

    static ThreadLocal<SimpleSessionStorage> threadLocalSessionStorage;

    public HybridWebSessionStorage( HttpApplication app )
    {
        app.EndRequest += Application_EndRequest;
    }

    public ISession GetSessionForKey( string factoryKey )
    {
        SimpleSessionStorage storage = GetSimpleSessionStorage();
        return storage.GetSessionForKey( factoryKey );
    }

    public void SetSessionForKey( string factoryKey,ISession session )
    {
        SimpleSessionStorage storage = GetSimpleSessionStorage();
        storage.SetSessionForKey( factoryKey,session );
    }

    public System.Collections.Generic.IEnumerable<ISession> GetAllSessions()
    {
        SimpleSessionStorage storage = GetSimpleSessionStorage();
        return storage.GetAllSessions();
    }

    private SimpleSessionStorage GetSimpleSessionStorage()
    {
        HttpContext context = HttpContext.Current;
        SimpleSessionStorage storage;
        if ( context != null )
        {
            storage = context.Items[ HttpContextSessionStorageKey ] as SimpleSessionStorage;
            if ( storage == null )
            {
                storage = new SimpleSessionStorage();
                context.Items[ HttpContextSessionStorageKey ] = storage;
            }
        }
        else
        {
            if ( threadLocalSessionStorage == null )
                threadLocalSessionStorage = new ThreadLocal<SimpleSessionStorage>( () => new SimpleSessionStorage() );
            storage = threadLocalSessionStorage.Value;
        }
        return storage;
    }

    private static readonly string HttpContextSessionStorageKey = "HttpContextSessionStorageKey";

    private void Application_EndRequest( object sender,EventArgs e )
    {
        NHibernateSession.CloseAllSessions();

        HttpContext context = HttpContext.Current;
        context.Items.Remove( HttpContextSessionStorageKey );
    }
}

注意：您必须确保在完成线程工作后调用NHibernateSession.CloseAllSessions(),因为当线程完成时,Application_EndRequest不会被触发.