Merge pull request #2161 from OPCFoundation/master371

Merge updated master371 branch in release/1.4.371

Author: mregen

Applications/ConsoleReferenceClient/Program.cs

@@ -130,7 +130,7 @@ public static async Task Main(string[] args)
                 };
 
                 // load the application configuration.
-                var config = await application.LoadApplicationConfiguration(silent: false);
+                var config = await application.LoadApplicationConfiguration(silent: false).ConfigureAwait(false);
 
                 // override logfile
                 if (logFile != null)
@@ -189,7 +189,7 @@ public static async Task Main(string[] args)
                             uaClient.UserIdentity = new UserIdentity(username, userpassword ?? string.Empty);
                         }
 
-                        bool connected = await uaClient.ConnectAsync(serverUrl.ToString(), false);
+                        bool connected = await uaClient.ConnectAsync(serverUrl.ToString(), false).ConfigureAwait(false);
                         if (connected)
                         {
                             output.WriteLine("Connected! Ctrl-C to quit.");
@@ -229,7 +229,7 @@ public static async Task Main(string[] args)
 
                                 if (jsonvalues && variableIds != null)
                                 {
-                                    await samples.ReadAllValuesAsync(uaClient, variableIds);
+                                    await samples.ReadAllValuesAsync(uaClient, variableIds).ConfigureAwait(false);
                                 }
 
                                 if (subscribe)
@@ -262,7 +262,7 @@ await samples.SubscribeAllValuesAsync(uaClient,
                                         publishingInterval: 5000,
                                         queueSize: 10,
                                         lifetimeCount: 12,
-                                        keepAliveCount: 2);
+                                        keepAliveCount: 2).ConfigureAwait(false);
 
                                     // Wait for DataChange notifications from MonitoredItems
                                     quit = quitEvent.WaitOne(timeout > 0 ? waitTime : Timeout.Infinite);

Applications/ConsoleReferenceClient/UAClient.cs

@@ -270,11 +270,27 @@ private void Client_ReconnectComplete(object sender, EventArgs e)
                 // if session recovered, Session property is null
                 if (m_reconnectHandler.Session != null)
                 {
-                    m_session = m_reconnectHandler.Session as Session;
+                    // ensure only a new instance is disposed
+                    // after reactivate, the same session instance may be returned
+                    if (!Object.ReferenceEquals(m_session, m_reconnectHandler.Session))
+                    {
+                        m_output.WriteLine("--- RECONNECTED TO NEW SESSION --- {0}", m_reconnectHandler.Session.SessionId);
+                        var session = m_session;
+                        session.KeepAlive -= Session_KeepAlive;
+                        m_session = m_reconnectHandler.Session as Session;
+                        m_session.KeepAlive += Session_KeepAlive;
+                        Utils.SilentDispose(session);
+                    }
+                    else
+                    {
+                        m_output.WriteLine("--- REACTIVATED SESSION --- {0}", m_reconnectHandler.Session.SessionId);
+                    }
+                }
+                else
+                {
+                    m_output.WriteLine("--- RECONNECT KeepAlive recovered ---");
                 }
             }
-
-            m_output.WriteLine("--- RECONNECTED ---");
         }
         #endregion
 

Libraries/Opc.Ua.Client/Session.cs

@@ -5766,10 +5766,17 @@ private bool BelowPublishRequestLimit(int requestCount)
         /// <summary>
         /// Returns the minimum number of active publish request that should be used.
         /// </summary>
+        /// <remarks>
+        /// Returns 0 if there are no subscriptions.
+        /// </remarks>
         private int GetMinPublishRequestCount()
         {
             lock (SyncRoot)
             {
+                if (m_subscriptions.Count == 0)
+                {
+                    return 0;
+                }
                 return Math.Max(m_subscriptions.Count, m_minPublishRequestCount);
             }
         }