Is my problem a XmlSerializer race condition?

See more:

C#5.0

serialization

Hi ^_^

Just when I think my Workflow Engine is in order, this happens >_<<br mode="hold" />
So, I have an instance of an IMessage that I need to clone. here is that process:

public IMessage Requeue()
{
    //New instance of this object.  Clone() is below
    var message = Clone();
    if (ReferenceEquals(message, this))
    {
        throw new InvalidOperationException("Clone must return a different object!");
    }

    //Reset the new instance
    message.Id = 0;
    message.Started = false;
    message.Complete = false;
    message.ReadTimestamp = null;
    message.CompleteTimestamp = null;
    message.Due = DateTime.Now + TimeSpan.FromSeconds(10);
        
    //save to the db    
    message.Save();

    //I only use this return for logging atm
    return message;
            
}

protected virtual IMessage Clone()
{
    IMessage message = (IMessage)Activator.CreateInstance(GetType());
    
    //Need to set the values of the derived type (methods below)
    message.SerializedData = Serialize();
    message = DeSerialize(message);

    return message;
}

public string Serialize()
{
    Type thisType = GetType();
    var serializer = new XmlSerializer(thisType);
    TextWriter writer = new StringWriter();
    serializer.Serialize(writer, this);

    //My issue is that in several cases, writer.ToString()==null?!?
    return writer.ToString();
}

The messages need to carry forward the derived type property values or the process is useless. I caught a case at message.Save(); where the SerializedData was null and reran the Clone() method. That time it worked.

My message parser is multi-threaded, but each message parse is handled in a single thread from start to finish (including re-queuing a clone).

I don't get why this isn't working unless XmlSerializer has some race condition issues or is not truly thread-safe. I couldn't find any evidence of this online, but I'm close to writing my own XmlSerializer. It seems like it would be easy enough but I don't want to if I don't have to.


Any advice would be appreciated
Thanks ^_^
Andy