ResolverTask: added for async resolution.

DnsServerCore/Dns/ResolverTask.cs

@@ -0,0 +1,61 @@
+/*
+Technitium DNS Server
+Copyright (C) 2020  Shreyas Zare (shreyas@technitium.com)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+using System;
+using System.Threading.Tasks;
+using TechnitiumLibrary.Net.Dns;
+
+namespace DnsServerCore.Dns
+{
+    class ResolverTask
+    {
+        #region variables
+
+        readonly DateTime _createdOn;
+        readonly TaskCompletionSource<DnsDatagram> _taskCompletionSource;
+
+        #endregion
+
+        #region constructor
+
+        public ResolverTask()
+        {
+            _createdOn = DateTime.UtcNow;
+            _taskCompletionSource = new TaskCompletionSource<DnsDatagram>();
+        }
+
+        #endregion
+
+        #region public
+
+        public bool IsStuck(int timeout)
+        {
+            return (DateTime.UtcNow - _createdOn).TotalMilliseconds > timeout;
+        }
+
+        #endregion
+
+        #region properties
+
+        public TaskCompletionSource<DnsDatagram> TaskCompletionSource
+        { get { return _taskCompletionSource; } }
+
+        #endregion
+    }
+}