* Handle cancellation token edge case (immediately canceled) in connection and channel CloseAsync

Author: lukebakken

projects/RabbitMQ.Client/Impl/Channel.cs

@@ -208,6 +208,14 @@ public Task CloseAsync(ushort replyCode, string replyText, bool abort,
         public async Task CloseAsync(ShutdownEventArgs args, bool abort,
             CancellationToken cancellationToken)
         {
+            CancellationToken originalCancellationToken = cancellationToken;
+            bool cancellationRequested = cancellationToken.IsCancellationRequested;
+            if (IsOpen && cancellationRequested)
+            {
+                // Note: we really do need to try and close this channel!
+                cancellationToken = CancellationToken.None;
+            }
+
             bool enqueued = false;
             var k = new ChannelCloseAsyncRpcContinuation(ContinuationTimeout, cancellationToken);
 
@@ -259,6 +267,7 @@ await ConsumerDispatcher.WaitForShutdownAsync()
                 MaybeDisposeContinuation(enqueued, k);
                 _rpcSemaphore.Release();
                 ChannelShutdownAsync -= k.OnConnectionShutdownAsync;
+                originalCancellationToken.ThrowIfCancellationRequested();
             }
         }
 

projects/RabbitMQ.Client/Impl/Connection.cs

@@ -320,6 +320,17 @@ public Task CloseAsync(ushort reasonCode, string reasonText, TimeSpan timeout, b
         ///</remarks>
         internal async Task CloseAsync(ShutdownEventArgs reason, bool abort, TimeSpan timeout, CancellationToken cancellationToken)
         {
+            if (timeout < InternalConstants.DefaultConnectionAbortTimeout)
+            {
+                timeout = InternalConstants.DefaultConnectionAbortTimeout;
+            }
+
+            if (IsOpen && cancellationToken.IsCancellationRequested)
+            {
+                // Note: we really do need to try and close this connection!
+                cancellationToken = CancellationToken.None;
+            }
+
             using var timeoutCts = new CancellationTokenSource(timeout);
             using var cts = CancellationTokenSource.CreateLinkedTokenSource(timeoutCts.Token, cancellationToken);
 
@@ -335,6 +346,7 @@ internal async Task CloseAsync(ShutdownEventArgs reason, bool abort, TimeSpan ti
             {
                 await OnShutdownAsync(reason)
                     .ConfigureAwait(false);
+
                 await _session0.SetSessionClosingAsync(false, cts.Token)
                     .ConfigureAwait(false);
 
@@ -393,7 +405,7 @@ await _session0.TransmitAsync(method, cts.Token)
 
             try
             {
-                await _mainLoopTask.WaitAsync(timeout, cts.Token)
+                await _mainLoopTask.WaitAsync(cts.Token)
                     .ConfigureAwait(false);
             }
             catch