Wcf + asp.net + multiple threads - asp.net

Question

I have the following scenario:
A Service that does nothing but sleeps for the amount of time the WPF specifies through the WebRequest onject:
public class WorkerSvc : IWorkerSvc
{
#region IWorkerSvc Members
public void DoWork(int timeToSleep)
{
Trace.WriteLine(DateTime.Now.ToString() + "\tInside Stress Service with TimeToSleep: " + timeToSleep.ToString());
if (timeToSleep == 0)
return;
Thread.Sleep(timeToSleep * 1000);
Trace.WriteLine(DateTime.Now.ToString() + "\tThe Thread woke up.");
}
Then an aspx page (separate project) that calls into the service:
protected void Page_Load(object sender, EventArgs e)
{
System.Diagnostics.Trace.WriteLine(DateTime.Now.ToString() + " \tInside default stress web site page load;");
using (WorkerService.WorkerSvcClient client = new StressWebSite.WorkerService.WorkerSvcClient())
{
System.Diagnostics.Trace.WriteLine(DateTime.Now.ToString() + " \tCreated a new client of Stress WCF Service;");
var rowdata = Request.QueryString["SleepValue"];
System.Diagnostics.Trace.WriteLine(DateTime.Now.ToString() + " \tDetected Sleep Value in the Request: " + rowdata);
int realData = 0;
if (!string.IsNullOrEmpty(rowdata))
{
if (int.TryParse(rowdata, out realData))
{
System.Diagnostics.Trace.WriteLine(DateTime.Now.ToString() + " \tBefore Dowork() with SleepValue: " + realData);
client.DoWork(realData);
System.Diagnostics.Trace.WriteLine(DateTime.Now.ToString() + " \tAfter DoWork() with SleepValue: " + realData);
Response.Write(realData.ToString());
//Response.End();
}
}
}
}
A WPF Form That spanws a number of threads which essentially post some data to an aspx page:
private void PerformStress()
{
WebRequest request = WebRequest.Create(string.Concat(this.txtStressPageUrl.Text, "?", "SleepValue", "=", this.txtSleepValue.Text));
Trace.WriteLine("Created Web Request");
request.Credentials = CredentialCache.DefaultCredentials;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream dataStream = response.GetResponseStream();
StreamReader reader = new StreamReader(dataStream);
string responseFromServer = reader.ReadToEnd();
//return responseFromServer;
}
private void button3_Click(object sender, RoutedEventArgs e)
{
int stressThreadsCount = 0;
if (!int.TryParse(this.txtStressThreadCount.Text, out stressThreadsCount))
MessageBox.Show("Enter number of threads to stress");
ThreadStart start = delegate()
{
DispatcherOperation op = Dispatcher.BeginInvoke(DispatcherPriority.Normal, new Action(PerformStress));
DispatcherOperationStatus status = op.Status;
while (status != DispatcherOperationStatus.Completed)
{
status = op.Wait(TimeSpan.FromMilliseconds(1000));
if (status == DispatcherOperationStatus.Aborted)
{
//
}
}
};
for (int i = 0; i < stressThreadsCount; i++)
{
var t = new Thread(start);
//this.runningThreads.Add(t);
t.Start();
//t.Join();
}
}
The problem is that it looks like eventhough I spawn several threads from the WPF side, to post to the aspx page, all the threads are processed in a serial manner, meaning each thread is waiting for the service to return.
I run this set up under cassiny.
I did not specify the WCF service's behavior to be a singleton.
Please help to ID the issue - I'd like to simulate multiple requests to the IIS and a page that calls into WCF to prove a concept.

Answer 1

Singleton will only affect how many objects will be created to service requests. By default, though, WCF services will only process a single request at a time. To change that, you should decorate your service implementation with
[ServiceBehavior(ConcurrencyMode = ConcurrencyMode.Multiple)]
For more info, see here: http://msdn.microsoft.com/en-us/library/system.servicemodel.concurrencymode.aspx