[feature] Provide cancellation token in AcceptMessageSession

[ddobric]

Method AcceptMessageSession should make a usage of cancellation.

AcceptMessageSession (TimeSpan, CancellationToken)

Following code could be in this case simplified:

public async Task Start(CancellationToken cancelToken)
       {
           Task[] tasks = new Task[2];

           tasks[0] = Task.Run(async () =>
           {
               while (!cancelToken.IsCancellationRequested)
               {
                   try
                   {
                       var session = await this.SessionClient.AcceptMessageSessionAsync();
                       Debug.WriteLine($"Session: {session.SessionId}");                      
                   }
                   catch (ServiceBusTimeoutException ex)
                   {
                     
                   }
               }
           }, cancelToken);

           tasks[1] = Task.Run(async ()=> {
               while (!cancelToken.IsCancellationRequested)
               {
                   await Task.Delay(500);
               }
           });

           Task.WaitAny(tasks);
       } 

With cancellation:

public async Task Start(CancellationToken cancelToken)
       {
           Task[] tasks = new Task[2];

           tasks[0] = Task.Run(async () =>
           {
               while (!cancelToken.IsCancellationRequested)
               {
                   try
                   {
                       var session = await this.SessionClient.AcceptMessageSessionAsync(cancelToken);                      
                   }
                   catch (ServiceBusTimeoutException ex)
                   {
                   }
               }
           }, cancelToken);
       }

[SeanFeldman]

It's not just AcceptMessageSession() almost all async operations that involve IO work should have that support. For example: Azure/azure-service-bus-dotnet#439, Azure/azure-service-bus-dotnet#258, and Azure/azure-service-bus-dotnet#675.

This is an issue with the client in general. I've tried to convince here, but it didn't happen. With the client moving to a new repository, I'll raise it there (Azure/azure-sdk-for-net#6653), which you can upvote if you'd like. Either way, it belongs to https://github.com/Azure/azure-sdk-for-net/

[Areson]

I'd like to add my support to this as well. I have a message queue feeding a constrained resource, and from time to time that resource will issue an alert that it needs to stop processing for a time. I have to close the QueueClient at that point, but the message pumps keep functioning despite the client being closed, which causes a lot of noise.

[Mortana89]

Same here, we should be able to suspend the message pump without closing the client (sending should still be possible)

[EldertGrootenboer]

If this issue still occurs using the latest SDK, please let us know and we can re-open the issue.