Question

I have been bitten by a poorly architected solution. It is not thread safe!

I have several shared classes and members in the solution, and during development all was cool…
BizTalk has sunk my battle ship.

We are using a custom BizTalk Adapter to call my assemblies. The Adapter is calling my code and running things in parallel, so I assume it is using multiple threads all under the same AppDomain.

What I would like to do is make my code run under its own AppDomain so the shared problems I have will not muck with each other.

I have a very simple class that the BizTalk adapter is instantiating then running a Process() method.

I would like to create a new AppDomain inside my Process() method, so each time BizTalk spins another thread, it will have its own version of the static classes and methods.

BizTalkAdapter Code:

  // this is inside the BizTalkAdapter and it is calling the Loader class //   private void SendMessage(IBaseMessage message, TransactionalTransmitProperties properties)     {          Stream strm = message.BodyPart.GetOriginalDataStream();         string connectionString = properties.ConnectionString;         string msgFileName = message.Context.Read('ReceivedFileName', 'http://schemas.microsoft.com/BizTalk/2003/file-properties') as string;           Loader loader = new Loader(strm, msgFileName, connectionString);         loader.Process();          EventLog.WriteEntry('Loader', 'Successfully processed: ' + msgFileName);      } 

This is the class BizTalk Calls:

public class Loader {      private string connectionString;     private string fileName;     private Stream stream;     private DataFile dataFile;      public Loader(Stream stream, string fileName, string connectionString)     {         this.connectionString = connectionString;         this.fileName = fileName;         this.stream = stream;     }        public void Process()     {          //*****  Create AppDomain HERE *****         // run following code entirely under that domain         dataFile = new DataFile(aredStream, fileName, connectionString);         dataFile.ParseFile();         dataFile.Save();         // get rid of the AppDomain here...      }  } 

FYI: The Loader class is in a seperate DLL from the dataFile class.

Any help would be appreciated. I will continue to working on making the code Thread-Safe, but I feel like this could be the ‘simple’ answer.

If anyone has any other thought, please throw in.

Thank you,
Keith

Just for completeness.

I did find that if I marked the send adapter as ‘Ordered Delivery’ in the ‘Transport Advanced Options’ dialog I was able to avoid the multi-thread issues I was having.

I figure this is another possible answer to my problem, but not necessarily to the question.

Answer 1

Using app domains you could do something like this:

public class Loader {      private string connectionString;     private string fileName;     private Stream stream;     private DataFile dataFile;      public Loader(Stream stream, string fileName, string connectionString)     {         this.connectionString = connectionString;         this.fileName = fileName;         this.stream = stream;     }        public void Process()     {         //*****  Create AppDomain HERE *****         string threadID = Thread.CurrentThread.ManagedThreadId.ToString();         AppDomain appDomain = AppDomain.CreateDomain(threadID);          DataFile dataFile =              (DataFile) appDomain.CreateInstanceAndUnwrap(                         '<DataFile AssemblyName>',                          'DataFile',                          true,                          BindingFlags.Default,                         null,                         new object[]                          {                              aredstream,                              filename,                              connectionString                          },                         null,                         null,                         null);         dataFile.ParseFile();         dataFile.Save();          appDomain.Unload(threadID);            } }