From 900c83f437c36f3b3d5385f64f26744884d6b2a3 Mon Sep 17 00:00:00 2001
From: Steve Molloy <smolloy@microsoft.com>
Date: Thu, 22 Aug 2024 16:01:16 -0700
Subject: [PATCH] [release/8.0-staging] Sys.RT.Caching.MemoryCache - Remove
 unhandled exception handler (#106221)

* Remove UnhandledException handler from MemoryCache to avoid deadlock.

* Update Sys.RT.Caching csproj for servicing build.
---
 .../src/System.Runtime.Caching.csproj          |  2 ++
 .../src/System/Runtime/Caching/MemoryCache.cs  | 18 ------------------
 2 files changed, 2 insertions(+), 18 deletions(-)

diff --git a/src/libraries/System.Runtime.Caching/src/System.Runtime.Caching.csproj b/src/libraries/System.Runtime.Caching/src/System.Runtime.Caching.csproj
index b3d85127f0212..241cbbffb2136 100644
--- a/src/libraries/System.Runtime.Caching/src/System.Runtime.Caching.csproj
+++ b/src/libraries/System.Runtime.Caching/src/System.Runtime.Caching.csproj
@@ -3,6 +3,8 @@
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent);$(NetCoreAppPrevious)-windows;$(NetCoreAppPrevious);$(NetCoreAppMinimum)-windows;$(NetCoreAppMinimum);netstandard2.0</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IsPackable>true</IsPackable>
+    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <ServicingVersion>1</ServicingVersion>
     <AddNETFrameworkPlaceholderFileToPackage>true</AddNETFrameworkPlaceholderFileToPackage>
     <AddXamarinPlaceholderFilesToPackage>true</AddXamarinPlaceholderFilesToPackage>
     <AddNETFrameworkAssemblyReferenceToPackage>true</AddNETFrameworkAssemblyReferenceToPackage>
diff --git a/src/libraries/System.Runtime.Caching/src/System/Runtime/Caching/MemoryCache.cs b/src/libraries/System.Runtime.Caching/src/System/Runtime/Caching/MemoryCache.cs
index e740eed69ed51..38514ce521abc 100644
--- a/src/libraries/System.Runtime.Caching/src/System/Runtime/Caching/MemoryCache.cs
+++ b/src/libraries/System.Runtime.Caching/src/System/Runtime/Caching/MemoryCache.cs
@@ -39,7 +39,6 @@ public class MemoryCache : ObjectCache, IEnumerable, IDisposable
         private bool _useMemoryCacheManager = true;
         private bool _throwOnDisposed;
         private EventHandler _onAppDomainUnload;
-        private UnhandledExceptionEventHandler _onUnhandledException;
 #if NETCOREAPP
         [UnsupportedOSPlatformGuard("browser")]
         private static bool _countersSupported => !OperatingSystem.IsBrowser();
@@ -219,9 +218,6 @@ private void InitDisposableMembers(NameValueCollection config)
                 EventHandler onAppDomainUnload = new EventHandler(OnAppDomainUnload);
                 appDomain.DomainUnload += onAppDomainUnload;
                 _onAppDomainUnload = onAppDomainUnload;
-                UnhandledExceptionEventHandler onUnhandledException = new UnhandledExceptionEventHandler(OnUnhandledException);
-                appDomain.UnhandledException += onUnhandledException;
-                _onUnhandledException = onUnhandledException;
                 dispose = false;
             }
             finally
@@ -238,16 +234,6 @@ private void OnAppDomainUnload(object unusedObject, EventArgs unusedEventArgs)
             Dispose();
         }
 
-        private void OnUnhandledException(object sender, UnhandledExceptionEventArgs eventArgs)
-        {
-            // if the CLR is terminating, dispose the cache.
-            // This will dispose the perf counters
-            if (eventArgs.IsTerminating)
-            {
-                Dispose();
-            }
-        }
-
         private static void ValidatePolicy(CacheItemPolicy policy)
         {
             if (policy.AbsoluteExpiration != ObjectCache.InfiniteAbsoluteExpiration
@@ -500,10 +486,6 @@ private void DisposeSafeCritical()
             {
                 appDomain.DomainUnload -= _onAppDomainUnload;
             }
-            if (_onUnhandledException != null)
-            {
-                appDomain.UnhandledException -= _onUnhandledException;
-            }
         }
 
         private object GetInternal(string key, string regionName)