Don't retry runtime operation if close called on the client. (#313)

* Don't retry if close called on the client.

* Encapsulate closeCalled

* add this.

src/Microsoft.Azure.EventHubs/Amqp/AmqpEventDataSender.cs

@@ -87,7 +87,7 @@ namespace Microsoft.Azure.EventHubs.Amqp
                     {
                         // Evaluate retry condition?
                         TimeSpan? retryInterval = this.RetryPolicy.GetNextRetryInterval(ex, timeoutHelper.RemainingTime(), ++retryCount);
-                        if (retryInterval != null)
+                        if (retryInterval != null && !this.EventHubClient.CloseCalled)
                         {
                             await Task.Delay(retryInterval.Value).ConfigureAwait(false);
                             shouldRetry = true;

src/Microsoft.Azure.EventHubs/Amqp/AmqpPartitionReceiver.cs

@@ -105,7 +105,7 @@ namespace Microsoft.Azure.EventHubs.Amqp
                 {
                     // Evaluate retry condition?
                     TimeSpan? retryInterval = this.RetryPolicy.GetNextRetryInterval(ex, timeoutHelper.RemainingTime(), ++retryCount);
-                    if (retryInterval != null)
+                    if (retryInterval != null && !this.EventHubClient.CloseCalled)
                     {
                         await Task.Delay(retryInterval.Value).ConfigureAwait(false);
                         shouldRetry = true;

src/Microsoft.Azure.EventHubs/EventHubClient.cs

@@ -18,6 +18,7 @@ namespace Microsoft.Azure.EventHubs
     public abstract class EventHubClient : ClientEntity
     {
         EventDataSender innerSender;
+        bool closeCalled = false;
 
         internal EventHubClient(EventHubsConnectionStringBuilder csb)
             : base($"{nameof(EventHubClient)}{ClientEntity.GetNextId()}({csb.EntityPath})")
@@ -241,6 +242,8 @@ namespace Microsoft.Azure.EventHubs
         /// <returns></returns>
         public sealed override async Task CloseAsync()
         {
+            this.closeCalled = true;
+
             EventHubsEventSource.Log.ClientCloseStart(this.ClientId);
             try
             {
@@ -560,6 +563,8 @@ namespace Microsoft.Azure.EventHubs
             set;
         }
 
+        internal bool CloseCalled { get => this.closeCalled; }
+
         internal EventDataSender CreateEventSender(string partitionId = null)
         {
             return this.OnCreateEventSender(partitionId);