Use .NET 9's System.Threading.Lock instead of object for locking (#27)

Author: MarkCiliaVincenti

SharpCoreDB.Benchmarks/FairComparisonBenchmark.cs

@@ -187,7 +187,7 @@ private void RunSQLite(int threads)
         {
             var perThread = RECORDS / threads;
             var tasks = new Task[threads];
-            var lockObj = new object();
+            Lock lockObj = new();
 
             for (int t = 0; t < threads; t++)
             {

SharpCoreDB.Extensions/DapperPerformanceExtensions.cs

@@ -11,7 +11,7 @@ namespace SharpCoreDB.Extensions;
 public static class DapperPerformanceExtensions
 {
     private static readonly Dictionary<string, PerformanceMetrics> _metricsCache = new();
-    private static readonly object _metricsLock = new();
+    private static readonly Lock _metricsLock = new();
 
     /// <summary>
     /// Executes a query with performance tracking.

SharpCoreDB/Database.Core.cs

@@ -36,7 +36,7 @@ public partial class Database : IDatabase, IDisposable
     private readonly DatabaseConfig? config;
     private readonly QueryCache? queryCache;
     private readonly PageCache? pageCache;
-    private readonly object _walLock = new();  // ✅ C# 14: target-typed new
+    private readonly Lock _walLock = new();  // ✅ C# 14: target-typed new
     private readonly ConcurrentDictionary<string, CachedQueryPlan> _preparedPlans = new();
 
     private readonly GroupCommitWAL? groupCommitWal;

SharpCoreDB/MVCC/MvccManager.cs

@@ -23,7 +23,7 @@ public sealed class MvccManager<TKey, TData> : IDisposable
     private readonly ConcurrentDictionary<long, MvccTransaction> _activeTransactions = new();
     private long _currentVersion;
     private long _nextTransactionId;
-    private readonly object _versionLock = new();
+    private readonly Lock _versionLock = new();
 
     /// <summary>
     /// Initializes a new instance of the <see cref="MvccManager{TKey, TData}"/> class.

SharpCoreDB/MVCC/VersionedRow.cs

@@ -69,7 +69,7 @@ public VersionedRow<TData> Update(TData newData, long newVersion) =>
 public sealed class VersionChain<TData> where TData : class
 {
     private readonly List<VersionedRow<TData>> _versions = [];
-    private readonly object _lock = new();
+    private readonly Lock _lock = new();
 
     /// <summary>
     /// Gets the number of versions in this chain.

SharpCoreDB/Optimizations/InsertOptimizations.cs

@@ -22,7 +22,7 @@ public sealed class DelayedColumnTranspose
     {
         private readonly List<Dictionary<string, object>> _rowBuffer = [];
         private bool _isTransposed;
-        private readonly object _transposeLock = new();
+        private readonly Lock _transposeLock = new();
 
         /// <summary>
         /// Adds a row WITHOUT transposing (O(1) operation).

SharpCoreDB/Services/AutoMaintenanceService.cs

@@ -16,7 +16,7 @@ public class AutoMaintenanceService : IDisposable
     private readonly System.Timers.Timer timer;
     private int writeCount = 0;
     private readonly int writeThreshold;
-    private readonly object @lock = new();
+    private readonly Lock @lock = new();
     private bool disposed = false;
 
     /// <summary>

SharpCoreDB/Services/Storage.Append.cs

@@ -21,7 +21,7 @@ public partial class Storage
     // Track buffered appends during transaction
     private readonly Dictionary<string, List<(byte[] data, long position)>> bufferedAppends = new();
     private readonly Dictionary<string, long> cachedFileLengths = new();  // ✅ NEW: Cache file lengths
-    private readonly object appendLock = new object();
+    private readonly Lock appendLock = new();
 
     /// <inheritdoc />
     [MethodImpl(MethodImplOptions.AggressiveOptimization)]

SharpCoreDB/Services/Storage.Core.cs

@@ -27,7 +27,7 @@ public partial class Storage : IStorage
 
     // Transaction support
     private readonly TransactionBuffer transactionBuffer;
-    private readonly object transactionLock = new object();
+    private readonly Lock transactionLock = new();
 
     /// <summary>
     /// Initializes a new instance of the <see cref="Storage"/> class.

SharpCoreDB/SharpCoreDB/Core/File/BufferedWriteManager.cs

@@ -19,7 +19,7 @@ public class BufferedWriteManager : IDisposable
 {
     // Per-file buffered writes
     private readonly Dictionary<string, FileWriteBuffer> fileBuffers = [];
-    private readonly object bufferLock = new object();
+    private readonly Lock bufferLock = new();
 
     private bool disposed = false;