Cover concurrent publishing on a shared connection

In preparation for #350.

Author: michaelklishin

projects/client/Unit/Unit.csproj

@@ -26,6 +26,7 @@
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">
+    <PackageReference Include="System.Runtime" Version="4.3.0" />
     <PackageReference Include="System.Collections.NonGeneric" Version="4.3.0" />
   </ItemGroup>
 

projects/client/Unit/src/unit/TestConcurrentAccessWithSharedConnection.cs

@@ -0,0 +1,80 @@
+// This source code is dual-licensed under the Apache License, version
+// 2.0, and the Mozilla Public License, version 1.1.
+//
+// The APL v2.0:
+//
+//---------------------------------------------------------------------------
+//   Copyright (c) 2007-2016 Pivotal Software, Inc.
+//
+//   Licensed under the Apache License, Version 2.0 (the "License");
+//   you may not use this file except in compliance with the License.
+//   You may obtain a copy of the License at
+//
+//       http://www.apache.org/licenses/LICENSE-2.0
+//
+//   Unless required by applicable law or agreed to in writing, software
+//   distributed under the License is distributed on an "AS IS" BASIS,
+//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//   See the License for the specific language governing permissions and
+//   limitations under the License.
+//---------------------------------------------------------------------------
+//
+// The MPL v1.1:
+//
+//---------------------------------------------------------------------------
+//  The contents of this file are subject to the Mozilla Public License
+//  Version 1.1 (the "License"); you may not use this file except in
+//  compliance with the License. You may obtain a copy of the License
+//  at http://www.mozilla.org/MPL/
+//
+//  Software distributed under the License is distributed on an "AS IS"
+//  basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+//  the License for the specific language governing rights and
+//  limitations under the License.
+//
+//  The Original Code is RabbitMQ.
+//
+//  The Initial Developer of the Original Code is Pivotal Software, Inc.
+//  Copyright (c) 2007-2016 Pivotal Software, Inc.  All rights reserved.
+//---------------------------------------------------------------------------
+
+using NUnit.Framework;
+
+using System;
+using System.Text;
+using System.Linq;
+using System.Threading;
+
+using RabbitMQ.Client;
+
+namespace RabbitMQ.Client.Unit {
+    [TestFixture]
+    public class TestConcurrentAccessWithSharedConnection : IntegrationFixture {
+
+        [Test]
+        public void TestConcurrentChannelOpenWithPublishing()
+        {
+            var n = 32;
+            var latch = new CountdownEvent(n);
+            foreach (var i in Enumerable.Range(0, n))
+            {
+                var t = new Thread(() => {
+                    // publishing on a shared channel is not supported
+                    // and would missing the point of this test anyway
+                    var ch = Conn.CreateModel();
+                    ch.ConfirmSelect();
+                    foreach (var j in Enumerable.Range(0, 10000))
+                    {
+                        var body = Encoding.ASCII.GetBytes(string.Empty);
+                        ch.BasicPublish(exchange: "", routingKey: "_______", basicProperties: ch.CreateBasicProperties(), body: body);
+                    }
+                    ch.WaitForConfirms(TimeSpan.FromSeconds(40));
+                    latch.Signal();
+                });
+                t.Start();                
+            }
+
+            Assert.IsTrue(latch.Wait(TimeSpan.FromSeconds(90)));
+        }
+    }
+}