use new Lock type for explicit synchronization

CompatBot/EventHandlers/BotReactionsHandler.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Linq;
 using System.Text.RegularExpressions;
+using System.Threading;
 using System.Threading.Tasks;
 using CompatBot.Commands.Attributes;
 using CompatBot.Database;
@@ -72,7 +73,7 @@ internal static partial class BotReactionsHandler
         [GeneratedRegex(@"\b((?<kot>kot(to)?)|(?<doggo>doggo|jarves))\b", RegexOptions.IgnoreCase | RegexOptions.Singleline | RegexOptions.ExplicitCapture)]
         private static partial Regex Paws();
         private static readonly Random Rng = new();
-        private static readonly object TheDoor = new();
+        private static readonly Lock TheDoor = new();
 
         public static DiscordEmoji RandomNegativeReaction { get { lock (TheDoor) return SadReactions[Rng.Next(SadReactions.Length)]; } }
         public static DiscordEmoji RandomPositiveReaction { get { lock (TheDoor) return ThankYouReactions[Rng.Next(ThankYouReactions.Length)]; } }

CompatBot/Utils/BufferCopyStream.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Buffers;
 using System.IO;
+using System.Threading;
 
 namespace CompatBot.Utils;
 
@@ -14,7 +15,7 @@ internal class BufferCopyStream : Stream, IDisposable
     private readonly byte[] writeBuf;
     private readonly byte[] readBuf;
     private int bufStart, bufLength;
-    private readonly object sync = new();
+    private readonly Lock sync = new();
     private bool disposed;
 
     public BufferCopyStream(Stream? baseStream, int bufferSize = 4096)

CompatBot/Utils/FixedLengthBuffer.cs

@@ -2,13 +2,14 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading;
 
 namespace CompatBot.Utils;
 
 internal class FixedLengthBuffer<TKey, TValue>: IList<TValue>
     where TKey: notnull
 {
-    internal readonly object SyncObj = new();
+    internal readonly Lock SyncObj = new();
 
     public FixedLengthBuffer(Func<TValue, TKey> keyGenerator)
     {