Fix Lock's usage of NativeRuntimeEventSource.Log to account for recur…

…sive accesses during its own class construction - `NativeRuntimeEventSource.Log` can be null if it's being constructed in the same thread earlier in the stack, added null checks Fixes dotnet#94728
kouvel · Jan 16, 2024 · 1daa56c · 1daa56c
1 parent a08d3fc
commit 1daa56c
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Showing 2 changed files with 5 additions and 5 deletions.
diff --git a/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Threading/Lock.NativeAot.cs b/src/coreclr/nativeaot/System.Private.CoreLib/src/System/Threading/Lock.NativeAot.cs
@@ -173,7 +173,7 @@ private static bool TryInitializeStatics()
                 s_minSpinCount = DetermineMinSpinCount();
 
                 // Also initialize some types that are used later to prevent potential class construction cycles
-                NativeRuntimeEventSource.Log.IsEnabled();
+                _ = NativeRuntimeEventSource.Log;
             }
             catch
             {

diff --git a/src/libraries/System.Private.CoreLib/src/System/Threading/Lock.cs b/src/libraries/System.Private.CoreLib/src/System/Threading/Lock.cs
@@ -444,9 +444,9 @@ private ThreadId TryEnterSlow(int timeoutMs, ThreadId currentThreadId)
 
         Wait:
             bool areContentionEventsEnabled =
-                NativeRuntimeEventSource.Log.IsEnabled(
+                NativeRuntimeEventSource.Log?.IsEnabled(
                     EventLevel.Informational,
-                    NativeRuntimeEventSource.Keywords.ContentionKeyword);
+                    NativeRuntimeEventSource.Keywords.ContentionKeyword) ?? false;
             AutoResetEvent waitEvent = _waitEvent ?? CreateWaitEvent(areContentionEventsEnabled);
             if (State.TryLockBeforeWait(this))
             {
@@ -463,7 +463,7 @@ private ThreadId TryEnterSlow(int timeoutMs, ThreadId currentThreadId)
                 long waitStartTimeTicks = 0;
                 if (areContentionEventsEnabled)
                 {
-                    NativeRuntimeEventSource.Log.ContentionStart(this);
+                    NativeRuntimeEventSource.Log!.ContentionStart(this);
                     waitStartTimeTicks = Stopwatch.GetTimestamp();
                 }
 
@@ -535,7 +535,7 @@ private ThreadId TryEnterSlow(int timeoutMs, ThreadId currentThreadId)
                     {
                         double waitDurationNs =
                             (Stopwatch.GetTimestamp() - waitStartTimeTicks) * 1_000_000_000.0 / Stopwatch.Frequency;
-                        NativeRuntimeEventSource.Log.ContentionStop(waitDurationNs);
+                        NativeRuntimeEventSource.Log!.ContentionStop(waitDurationNs);
                     }
 
                     return currentThreadId;