[jboss-user] [JBoss Web Services Development] New message: "Re: Parallel invocations of JaxWS services and getPort"

[Andrew Dinn]

User development,

A new message was posted in the thread "Parallel invocations of JaxWS services and getPort":

http://community.jboss.org/message/526276#526276

Author  : Andrew Dinn
Profile : http://community.jboss.org/people/adinn

Message:
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richard.opalka at jboss.com wrote:>  
> Hi Andrew,
>  
>    this is the problem of *broken by design JAX-WS specification* 
>  
> *Explanation:*
>    One of the problems when reusing proxy concurently is JAX-WS specification allows you to set invocation related properties on the proxy using BindingProvider methods. Consider the following code:
>  
> public void configureSession(EchoService serviceProxy, boolean keepSession)
> {
>    BindingProvider bp = (BindingProvider)serviceProxy;   bp.getRequestContext().put( BindingProvider.SESSION_MAINTAIN_PROPERTY, keepSession );
> }
> 
> If you would call above method on one proxy instance in e.g. 2 threads concurrently and each thread will set different keepSession policy, how would you implement this properly for the following scenario?
>  
> thread1.configureSession(proxy, true);
> thread2.configureSession(proxy, false);
> thread1.callService(proxy);
> thread2.callService(proxy);
> assertThereAreSessions(thread1);
> assertThereAreNoSession(thread2);
>  
> Do you see what I mean?

Yes, I understand that is the problme. That was what I was trying tyo explain.
 
> mailto:richard.opalka at jboss.com wrote:
>  
>  *Suggestion:*
>  
> Create/use service proxy per thread, not reuse it for multiple threads 
>  
 
Hm, I obviously did nto make myself clear. I am creating a new proxy for each thread. The problem is that they still interfere with each other. My code looks like this
 
> Service myService = getMyService(name, wsdl)
> final MyPort port1 = myService.getPort(endpointRef, MyPort.class, new AddressingFeature(true));
> final MyPort port2 = myService.getPort(endpointRef, MyPort.class, new AddressingFeature(true));
> configurePort(port1);
> cvonfigurePort(port2);
> Thread thread1 = new Thread() {
>   port1.myMethod()
> }
> Thread thread2 = new Thread() {
>   port2.myMethod()
> }
> 
> thread1.start();
> thread2.start();
> 
 
So, the problem appears to be happening even when I create a different port for each thread. Occasionally, the data associated with port 1 is overwritten and I end up with two calls on the server side both using the data from port 2. The data in question is set by a JaxWS handler on the calling side and read by a JaxWS handler on the server side. The client adds a header and the server removes it and uses it to set up the current transaction for the thread in a ThreadLocal.
 
I traced the code using Byteman to bytecode-inject print statements into the client just before the call to the proxy method and into the server as it enters the service method. Wen I run with 10 threads in parallel I occasionally see distinct values on the client side getting replaced with one value on the server side. If I switch on any other trace or inject more printouts the error does not normmally show because the timing of the threads changes.

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