Added paused activity socket events

CryptoExchange.Net/CryptoExchange.Net.xml

@@ -2689,6 +2689,16 @@
             Connecting restored event
             </summary>
         </member>
+        <member name="E:CryptoExchange.Net.Sockets.SocketConnection.ActivityPaused">
+            <summary>
+            The connection is paused event
+            </summary>
+        </member>
+        <member name="E:CryptoExchange.Net.Sockets.SocketConnection.ActivityUnpaused">
+            <summary>
+            The connection is unpaused event
+            </summary>
+        </member>
         <member name="E:CryptoExchange.Net.Sockets.SocketConnection.Closed">
             <summary>
             Connecting closed event
@@ -2858,6 +2868,16 @@
             Event when the connection is restored. Timespan parameter indicates the time the socket has been offline for before reconnecting
             </summary>
         </member>
+        <member name="E:CryptoExchange.Net.Sockets.UpdateSubscription.ActivityPaused">
+            <summary>
+            Event when the connection to the server is paused. No operations can be performed while paused
+            </summary>
+        </member>
+        <member name="E:CryptoExchange.Net.Sockets.UpdateSubscription.ActivityUnpaused">
+            <summary>
+            Event when the connection to the server is unpaused
+            </summary>
+        </member>
         <member name="E:CryptoExchange.Net.Sockets.UpdateSubscription.Exception">
             <summary>
             Event when an exception happened

CryptoExchange.Net/SocketClient.cs

@@ -161,6 +161,11 @@ namespace CryptoExchange.Net
                     semaphoreSlim.Release();
             }
 
+            if (socket.PausedActivity)
+            {
+                log.Write(LogVerbosity.Info, "Socket has been paused, can't subscribe at this moment");
+                return new CallResult<UpdateSubscription>(default, new ServerError("Socket is paused"));
+            }
 
             if (request != null)
             {

CryptoExchange.Net/Sockets/SocketConnection.cs

@@ -25,6 +25,14 @@ namespace CryptoExchange.Net.Sockets
         /// </summary>
         public event Action<TimeSpan>? ConnectionRestored;
         /// <summary>
+        /// The connection is paused event
+        /// </summary>
+        public event Action? ActivityPaused;
+        /// <summary>
+        /// The connection is unpaused event
+        /// </summary>
+        public event Action? ActivityUnpaused;
+        /// <summary>
         /// Connecting closed event
         /// </summary>
         public event Action? Closed;
@@ -60,11 +68,26 @@ namespace CryptoExchange.Net.Sockets
         /// Time of disconnecting
         /// </summary>
         public DateTime? DisconnectTime { get; set; }
+
         /// <summary>
         /// If activity is paused
         /// </summary>
-        public bool PausedActivity { get; set; }
+        public bool PausedActivity
+        {
+            get => pausedActivity;
+            set
+            {
+                if (pausedActivity != value)
+                {
+                    pausedActivity = value;
+                    log.Write(LogVerbosity.Debug, "Paused activity: " + value);
+                    if(pausedActivity) ActivityPaused?.Invoke();
+                    else ActivityUnpaused?.Invoke();
+                }
+            }
+        }
 
+        private bool pausedActivity;
         private readonly List<SocketSubscription> handlers;
         private readonly object handlersLock = new object();
 
@@ -155,7 +178,7 @@ namespace CryptoExchange.Net.Sockets
                 var sw = Stopwatch.StartNew();
                 lock (handlersLock)
                 {
-                    foreach (var handler in handlers)
+                    foreach (var handler in handlers.ToList())
                     {
                         currentSubscription = handler;
                         if (handler.Request == null)

CryptoExchange.Net/Sockets/UpdateSubscription.cs

@@ -29,6 +29,24 @@ namespace CryptoExchange.Net.Sockets
             remove => connection.ConnectionRestored -= value;
         }
 
+        /// <summary>
+        /// Event when the connection to the server is paused. No operations can be performed while paused
+        /// </summary>
+        public event Action ActivityPaused
+        {
+            add => connection.ActivityPaused += value;
+            remove => connection.ActivityPaused -= value;
+        }
+
+        /// <summary>
+        /// Event when the connection to the server is unpaused
+        /// </summary>
+        public event Action ActivityUnpaused
+        {
+            add => connection.ActivityUnpaused += value;
+            remove => connection.ActivityUnpaused -= value;
+        }
+
         /// <summary>
         /// Event when an exception happened
         /// </summary>