From edea1d4906f403f5769035b46a339f855775ab50 Mon Sep 17 00:00:00 2001
From: Kamron Batman <3953314+kamronbatman@users.noreply.github.com>
Date: Thu, 13 May 2021 18:22:42 -0700
Subject: [PATCH] fix(core): Fixes core tick count for VMs (#600)

Some architectures (specifically docker) have an issue with tick count and high precision timing.
This handles those weird cases so instead of outright freezing, you may get timer precision loss.
---
 Projects/Server/Main.cs | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/Projects/Server/Main.cs b/Projects/Server/Main.cs
index 15e7732e0..0612de954 100644
--- a/Projects/Server/Main.cs
+++ b/Projects/Server/Main.cs
@@ -125,12 +125,26 @@ namespace Server
         [ThreadStatic]
         private static DateTime _now;
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private static long GetTicks() => 1000L * Stopwatch.GetTimestamp() / Stopwatch.Frequency;
+        // For Unix Stopwatch.Frequency is normalized to 1ns
+        // We don't anticipate needing this for Windows/OSX
+        private static long _maxTickCountBeforePrecisionLoss = long.MaxValue / 1000L;
+        private static long _ticksPerMillisecond = Stopwatch.Frequency / 1000L;
 
         public static long TickCount
         {
-            get => _tickCount == 0 ? GetTicks() : _tickCount;
+            get
+            {
+                if (_tickCount != 0)
+                {
+                    return _tickCount;
+                }
+
+                var timestamp = Stopwatch.GetTimestamp();
+                return timestamp > _maxTickCountBeforePrecisionLoss
+                    ? timestamp / _ticksPerMillisecond
+                    // No precision loss
+                    : 1000L * timestamp / Stopwatch.Frequency;
+            }
             set => _tickCount = value;
         }