chore: Leverage new Lock types (#4983)

Author: jamescrosswell

GlobalUsings.cs

@@ -1,5 +1,12 @@
 // These are used in all projects except samples.
 
+// Use the new System.Threading.Lock type on .NET 9+, which enables compiler optimisations.
+// On earlier targets, alias it to object so the same lock pattern works everywhere,
+// but don't use the variant of "Polyfill", as it may cause issues on Runtimes that support "Thread.Abort" (e.g. .NET Framework)
+#if !NET9_0_OR_GREATER
+global using Lock = object;
+#endif
+
 global using System.Buffers;
 global using System.Collections;
 global using System.Collections.Concurrent;

src/Sentry.Log4Net/SentryAppender.cs

@@ -10,7 +10,7 @@ public class SentryAppender : AppenderSkeleton
     private readonly Func<string, IDisposable> _initAction;
     private volatile IDisposable? _sdkHandle;
 
-    private readonly object _initSync = new();
+    private readonly Lock _initSync = new();
 
     internal static readonly SdkVersion NameAndVersion
         = typeof(SentryAppender).Assembly.GetNameAndVersion();

src/Sentry.Maui/Internal/MauiDeviceData.cs

@@ -6,10 +6,8 @@ namespace Sentry.Maui.Internal;
 
 internal static class MauiDeviceData
 {
-#if NET9_0_OR_GREATER && ANDROID
+#if ANDROID
     private static readonly Lock JniLock = new();
-#elif ANDROID
-    private static readonly object JniLock = new();
 #endif
 
     public static void ApplyMauiDeviceData(this Device device, IDiagnosticLogger? logger,

src/Sentry.Maui/Internal/ScreenshotAttachment.cs

@@ -27,10 +27,8 @@ internal class ScreenshotAttachmentContent : IAttachmentContent
 {
     private readonly SentryMauiOptions _options;
 
-#if NET9_0_OR_GREATER && ANDROID
+#if ANDROID
     private static readonly Lock JniLock = new();
-#elif ANDROID
-    private static readonly object JniLock = new();
 #endif
 
     public ScreenshotAttachmentContent(SentryMauiOptions options)

src/Sentry/Internal/Hub.cs

@@ -8,7 +8,7 @@ namespace Sentry.Internal;
 
 internal class Hub : IHub, IDisposable
 {
-    private readonly object _sessionPauseLock = new();
+    private readonly Lock _sessionPauseLock = new();
 
     private readonly ISystemClock _clock;
     private readonly ISessionManager _sessionManager;

src/Sentry/Internal/InstallationIdHelper.cs

@@ -5,7 +5,7 @@ namespace Sentry.Internal;
 
 internal class InstallationIdHelper(SentryOptions options)
 {
-    private readonly object _installationIdLock = new();
+    private readonly Lock _installationIdLock = new();
     private string? _installationId;
 
     public string? TryGetInstallationId()

src/Sentry/Internal/Signal.cs

@@ -2,7 +2,7 @@ namespace Sentry.Internal;
 
 internal class Signal : IDisposable
 {
-    private readonly object _lock = new();
+    private readonly Lock _lock = new();
     private readonly SemaphoreSlim _semaphore = new(0, 1);
 
     public Signal(bool isReleasedInitially = false)

src/Sentry/Scope.cs

@@ -22,7 +22,7 @@ public class Scope : IEventLike
 
     internal bool Locked { get; set; }
 
-    private readonly object _lastEventIdSync = new();
+    private readonly Lock _lastEventIdSync = new();
     private SentryId _lastEventId;
 
     internal SentryId LastEventId
@@ -43,7 +43,7 @@ internal SentryId LastEventId
         }
     }
 
-    private readonly object _evaluationSync = new();
+    private readonly Lock _evaluationSync = new();
     private volatile bool _hasEvaluated;
 
     /// <summary>

src/Sentry/SentryMessageHandler.cs

@@ -10,7 +10,7 @@ public abstract class SentryMessageHandler : DelegatingHandler
 {
     private readonly IHub _hub;
     private readonly SentryOptions? _options;
-    private readonly object _innerHandlerLock = new();
+    private readonly Lock _innerHandlerLock = new();
 
     /// <summary>
     /// Constructs an instance of <see cref="SentryMessageHandler"/>.

src/Sentry/TransactionTracer.cs

@@ -316,7 +316,7 @@ private void AddChildSpan(SpanTracer span)
 
     private class LastActiveSpanTracker
     {
-        private readonly object _lock = new object();
+        private readonly Lock _lock = new();
 
         private readonly Lazy<Stack<ISpan>> _trackedSpans = new();
         private Stack<ISpan> TrackedSpans => _trackedSpans.Value;