From 0dd30412e2f48b47bb5725a310f18bb42e78631d Mon Sep 17 00:00:00 2001
From: Tim Haasdyk <tim_haasdyk@sil.org>
Date: Tue, 24 Mar 2026 14:00:44 +0100
Subject: [PATCH] Fix InitializeConstructors race condition

---
 .../Infrastructure/Impl/CmObjectSurrogate.cs  | 20 +++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/SIL.LCModel/Infrastructure/Impl/CmObjectSurrogate.cs b/src/SIL.LCModel/Infrastructure/Impl/CmObjectSurrogate.cs
index 69123547..e9a67288 100644
--- a/src/SIL.LCModel/Infrastructure/Impl/CmObjectSurrogate.cs
+++ b/src/SIL.LCModel/Infrastructure/Impl/CmObjectSurrogate.cs
@@ -33,6 +33,7 @@ namespace SIL.LCModel.Infrastructure.Impl
 	internal sealed class CmObjectSurrogate : ICmObjectSurrogate //, IEquatable<CmObjectSurrogate>
 	{
 		private static Dictionary<string, ConstructorInfo> s_classToConstructorInfo;
+		private static readonly object s_constructorLock = new object();
 		/// <summary>
 		/// It's common that hundreds of thousands of surrogates only use a few hundred class names. This is a local interning
 		/// of those names.
@@ -225,16 +226,19 @@ internal static CmObjectSurrogate CreateSnapshot(ICmObject obj)
 
 		internal static void InitializeConstructors(List<Type> cmObjectTypes)
 		{
-			if (s_classToConstructorInfo != null) return;
-
-			s_classToConstructorInfo = new Dictionary<string, ConstructorInfo>();
-			// Get default constructor.
-			// Only do this once, since they are stored in a static data member.
-			foreach (var lcmType in cmObjectTypes)
+			lock (s_constructorLock)
 			{
-				if (lcmType.IsAbstract) continue;
+				if (s_classToConstructorInfo != null) return;
+
+				s_classToConstructorInfo = new Dictionary<string, ConstructorInfo>();
+				// Get default constructor.
+				// Only do this once, since they are stored in a static data member.
+				foreach (var lcmType in cmObjectTypes)
+				{
+					if (lcmType.IsAbstract) continue;
 
-				s_classToConstructorInfo.Add(lcmType.Name, lcmType.GetConstructor(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, null, Type.EmptyTypes, null));
+					s_classToConstructorInfo.Add(lcmType.Name, lcmType.GetConstructor(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, null, Type.EmptyTypes, null));
+				}
 			}
 		}