From 3a52a991648b736ebe6bd348d3ac4db570970bc6 Mon Sep 17 00:00:00 2001
From: Tim Haasdyk <tim_haasdyk@sil.org>
Date: Tue, 5 May 2026 12:21:32 +0200
Subject: [PATCH] Fix LcmMetaDataCache race condition on static Flid counter

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

diff --git a/src/SIL.LCModel/Infrastructure/Impl/LcmMetaDataCache.cs b/src/SIL.LCModel/Infrastructure/Impl/LcmMetaDataCache.cs
index c2646c2b..b1e6886b 100644
--- a/src/SIL.LCModel/Infrastructure/Impl/LcmMetaDataCache.cs
+++ b/src/SIL.LCModel/Infrastructure/Impl/LcmMetaDataCache.cs
@@ -69,25 +69,29 @@ internal sealed class LcmMetaDataCache : IFwMetaDataCacheManaged, IFwMetaDataCac
 		#endregion Data Members for IFwMetaDataCache Support
 
 		#region Construction
+		private static readonly object s_constructorLock = new object();
 
 		/// <summary>
 		/// Constructor.
 		/// </summary>
 		internal LcmMetaDataCache()
 		{
-			m_initialized = false;
+			lock (s_constructorLock)
+			{
+				m_initialized = false;
 
-			// Reset static counters for attrs.
-			VirtualPropertyAttribute.ResetFlidCounter();
-			FieldDescription.ClearDataAbout();
+				// Reset static counters for attrs.
+				VirtualPropertyAttribute.ResetFlidCounter();
+				FieldDescription.ClearDataAbout();
 
-			var cmObjectTypesBaseFirst = CmObjectTypesBaseFirst();
+				var cmObjectTypesBaseFirst = CmObjectTypesBaseFirst();
 
-			CmObjectSurrogate.InitializeConstructors(cmObjectTypesBaseFirst);
+				CmObjectSurrogate.InitializeConstructors(cmObjectTypesBaseFirst);
 
-			InitializeMetaDataCache(cmObjectTypesBaseFirst);
+				InitializeMetaDataCache(cmObjectTypesBaseFirst);
 
-			m_initialized = true;
+				m_initialized = true;
+			}
 		}
 
 		/// <summary/>