fix(timers): Fixes multiple issue with timer wheel (#705)

* Fixed an issue where a timer truncated the link list.
* Fixed an issue where a timer stopped and started itself within an OnTick causing it to remove itself from the link list, but still think it's running.

Projects/Server/Timer/Timer.TimerWheel.cs

@@ -74,22 +74,28 @@ namespace Server
                 }
 
                 var timer = _rings[i][ringIndex];
-
                 if (timer != null)
                 {
                     events = true;
 
-                    if (i > 0 && timer._remaining > 0)
+                    do
                     {
-                        Promote(timer);
+                        var next = _rings[i][ringIndex] = timer._nextTimer;
-                    }
-                    else
-                    {
-                        Execute(timer);
-                    }
 
-                    // Clear the slot
+                        timer.Detach();
-                    _rings[i][ringIndex] = null;
+
+                        if (i > 0 && timer._remaining > 0)
+                        {
+                            // Promote
+                            AddTimer(timer, timer._remaining);
+                        }
+                        else
+                        {
+                            Execute(timer);
+                        }
+
+                        timer = next;
+                    } while (timer != null);
                 }
 
                 if (!turnNextWheel)
@@ -103,50 +109,29 @@ namespace Server
 
         private static void Execute(Timer timer)
         {
-            do
+            var finished = timer.Count != 0 && ++timer.Index >= timer.Count;
+
+            var version = timer.Version;
+
+            var prof = timer.GetProfile();
+            prof?.Start();
+            timer.OnTick();
+            prof?.Finish();
+
+            // If the timer has not been stopped, and it has not been altered (restarted, returned etc)
+            if (timer.Running && timer.Version == version)
             {
-                var next = timer._nextTimer;
+                if (finished)
-                var prof = timer.GetProfile();
-                var finished = timer.Count != 0 && ++timer.Index >= timer.Count;
-
-                // We remove it before `OnTick()` so time references can be nulled and returned to cache safely from within OnTick.
-                // This can be done in OnTick by checking if Index < Count - 1 (still more iterations left)
-                RemoveTimer(timer);
-
-                var version = timer.Version;
-
-                prof?.Start();
-                timer.OnTick();
-                prof?.Finish();
-
-                // If the timer has not been stopped, and it has not been altered (shared timers)
-                if (timer.Running && timer.Version == version)
                 {
-                    if (finished)
+                    timer.Stop();
-                    {
-                        timer.Stop();
-                    }
-                    else
-                    {
-                        timer.Delay = timer.Interval;
-                        timer.Next = Core.Now + timer.Interval;
-                        AddTimer(timer, (long)timer.Delay.TotalMilliseconds);
-                    }
                 }
-
+                else
-                timer = next;
+                {
-            } while (timer != null);
+                    timer.Delay = timer.Interval;
-        }
+                    timer.Next = Core.Now + timer.Interval;
-
+                    AddTimer(timer, (long)timer.Delay.TotalMilliseconds);
-        private static void Promote(Timer timer)
+                }
-        {
+            }
-            do
-            {
-                var next = timer._nextTimer;
-                RemoveTimer(timer);
-                AddTimer(timer, timer._remaining);
-                timer = next;
-            } while (timer != null);
         }
 
         private static void AddTimer(Timer timer, long delay)
@@ -182,6 +167,7 @@ namespace Server
                     timer._slot = (int)slot;
 
                     _rings[i][slot] = timer;
+
                     break;
                 }
 
@@ -191,16 +177,6 @@ namespace Server
             }
         }
 
-        private static void RemoveTimer(Timer timer)
-        {
-            if (timer._prevTimer == null)
-            {
-                _rings[timer._ring][timer._slot] = timer._nextTimer;
-            }
-
-            timer.Detach();
-        }
-
         public static void DumpInfo(TextWriter tw)
         {
             tw.WriteLine("Date: {0}\n", Core.Now.ToLocalTime());

Projects/Server/Timer/Timer.cs

@@ -81,6 +81,7 @@ namespace Server
                 return this;
             }
 
+            Index = 0;
             Running = true;
             AddTimer(this, (long)Delay.TotalMilliseconds);
 
@@ -101,8 +102,15 @@ namespace Server
                 return;
             }
 
-            RemoveTimer(this);
+            // We are at the head
+            if (_rings[_ring][_slot] == this)
+            {
+                _rings[_ring][_slot] = _nextTimer;
+            }
+
+            Detach();
             Running = false;
+            Version++;
             var prof = GetProfile();
 
             if (prof != null)

Projects/Server/World/EntityPersistence.cs

@@ -162,6 +162,8 @@ namespace Server
             using FileStream bin = new FileStream(dataPath, FileMode.Open, FileAccess.Read, FileShare.Read);
             BufferReader br = null;
 
+            var deleteAllFailures = false;
+
             foreach (var entry in entities)
             {
                 T t = entry.Entity;
@@ -210,11 +212,21 @@ namespace Server
                     Console.WriteLine($"***** Bad deserialize of {t.GetType()} *****");
                     Console.WriteLine(error);
 
-                    Console.WriteLine("Delete the object and continue? (y/n)");
+                    ConsoleKey pressedKey;
 
-                    if (Console.ReadKey(true).Key != ConsoleKey.Y)
+                    if (!deleteAllFailures)
                     {
-                        throw new Exception("Deserialization failed.");
+                        Console.WriteLine("Delete the object and continue? (y/n/a)");
+                        pressedKey = Console.ReadKey(true).Key;
+
+                        if (pressedKey == ConsoleKey.A)
+                        {
+                            deleteAllFailures = true;
+                        }
+                        else if (pressedKey != ConsoleKey.Y)
+                        {
+                            throw new Exception("Deserialization failed.");
+                        }
                     }
 
                     t.Delete();

Projects/UOContent/Engines/Spawners/BaseSpawner.cs

@@ -110,7 +110,11 @@ namespace Server.Engines.Spawners
             {
                 m_Count = value;
 
-                if (m_Timer != null && (!IsFull && !m_Timer.Running || IsFull && m_Timer.Running))
+                if (IsFull)
+                {
+                    m_Timer?.Stop();
+                }
+                else if (m_Timer?.Running != true)
                 {
                     DoTimer();
                 }
@@ -372,11 +376,8 @@ namespace Server.Engines.Spawners
 
         public void Stop()
         {
-            if (m_Running)
+            m_Timer?.Stop();
-            {
+            m_Running = false;
-                m_Timer?.Stop();
-                m_Running = false;
-            }
         }
 
         public void Defrag()