From cc696254242038fe03ce5feba936980ea20e2eac Mon Sep 17 00:00:00 2001
From: vsadov <8218165+VSadov@users.noreply.github.com>
Date: Thu, 3 Apr 2025 10:30:59 -0700
Subject: [PATCH] Moved a static field initialization from Thread to
 ProcessorIdCache

---
 .../src/System/Threading/ProcessorIdCache.cs               | 7 +++++++
 .../System.Private.CoreLib/src/System/Threading/Thread.cs  | 7 -------
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/Threading/ProcessorIdCache.cs b/src/libraries/System.Private.CoreLib/src/System/Threading/ProcessorIdCache.cs
index a31516c94f048a..25fac4050acf13 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Threading/ProcessorIdCache.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Threading/ProcessorIdCache.cs
@@ -22,6 +22,10 @@ internal static class ProcessorIdCache
         // We will not adjust higher than this though.
         private const int MaxIdRefreshRate = 5000;
 
+        // a speed check will determine refresh rate of the cache and will report if caching is not advisable.
+        // we will record that in a readonly static so that it could become a JIT constant and bypass caching entirely.
+        private static readonly bool s_isProcessorNumberReallyFast = ProcessorIdCache.ProcessorNumberSpeedCheck();
+
         private static int RefreshCurrentProcessorId()
         {
             int currentProcessorId = Thread.GetCurrentProcessorNumber();
@@ -44,6 +48,9 @@ private static int RefreshCurrentProcessorId()
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal static int GetCurrentProcessorId()
         {
+            if (s_isProcessorNumberReallyFast)
+                return Thread.GetCurrentProcessorNumber();
+
             int currentProcessorIdCache = t_currentProcessorIdCache--;
             if ((currentProcessorIdCache & ProcessorIdCacheCountDownMask) == 0)
             {
diff --git a/src/libraries/System.Private.CoreLib/src/System/Threading/Thread.cs b/src/libraries/System.Private.CoreLib/src/System/Threading/Thread.cs
index 4dc0a5002e7e78..f92abc7789ab7c 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Threading/Thread.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Threading/Thread.cs
@@ -719,16 +719,9 @@ public static void SetData(LocalDataStoreSlot slot, object? value)
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static int GetCurrentProcessorId()
         {
-            if (s_isProcessorNumberReallyFast)
-                return GetCurrentProcessorNumber();
-
             return ProcessorIdCache.GetCurrentProcessorId();
         }
 
-        // a speed check will determine refresh rate of the cache and will report if caching is not advisable.
-        // we will record that in a readonly static so that it could become a JIT constant and bypass caching entirely.
-        private static readonly bool s_isProcessorNumberReallyFast = ProcessorIdCache.ProcessorNumberSpeedCheck();
-
 #if FEATURE_WASM_MANAGED_THREADS
         [ThreadStatic]
         public static bool ThrowOnBlockingWaitOnJSInteropThread;