Fix race condition in MemoryCache.Compact()

StevenTCramer · StevenTCramer · commit bf34c4f3a2c6 · 2025-11-02T12:56:58.000+07:00
Fixes #12430 Add ToArray() snapshot before OrderBy to prevent concurrent modification exceptions during enumeration of ConcurrentDictionary.
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Utilities/MemoryCache`2.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Utilities/MemoryCache`2.cs
@@ -64,7 +64,7 @@ public void Set(TKey key, TValue value)
 
     protected virtual void Compact()
     {
-        var kvps = _dict.OrderBy(x => x.Value.LastAccess).ToArray();
+        var kvps = _dict.ToArray().OrderBy(x => x.Value.LastAccess).ToArray();
 
         for (var i = 0; i < _sizeLimit / 2; i++)
         {

Original file line number	Diff line number	Diff line change
`@@ -64,7 +64,7 @@ public void Set(TKey key, TValue value)`
`64`	`64`
`65`	`65`	`protected virtual void Compact()`
`66`	`66`	`{`
`67`		`- var kvps = _dict.OrderBy(x => x.Value.LastAccess).ToArray();`
	`67`	`+ var kvps = _dict.ToArray().OrderBy(x => x.Value.LastAccess).ToArray();`
`68`	`68`
`69`	`69`	`for (var i = 0; i < _sizeLimit / 2; i++)`
`70`	`70`	`{`