From 235ff8e7418b0f3e24cbbef58e18dd589dc192dc Mon Sep 17 00:00:00 2001
From: Arthur Vickers <ajcvickers@hotmail.com>
Date: Tue, 17 Jan 2023 13:55:20 +0000
Subject: [PATCH] Move taking of lock earlier to avoid race in PruneCallback

Fixes #29952
---
 .../SqliteConnectionFactory.cs                | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/src/Microsoft.Data.Sqlite.Core/SqliteConnectionFactory.cs b/src/Microsoft.Data.Sqlite.Core/SqliteConnectionFactory.cs
index 1103aaf2fe8..1587f0cf117 100644
--- a/src/Microsoft.Data.Sqlite.Core/SqliteConnectionFactory.cs
+++ b/src/Microsoft.Data.Sqlite.Core/SqliteConnectionFactory.cs
@@ -138,20 +138,21 @@ private void PruneCallback(object? _)
                 }
             }
 
-            for (var i = _idlePoolGroups.Count - 1; i >= 0; i--)
+            _lock.EnterWriteLock();
+
+            try
             {
-                var poolGroup = _idlePoolGroups[i];
 
-                if (!poolGroup.Clear())
+                for (var i = _idlePoolGroups.Count - 1; i >= 0; i--)
                 {
-                    _idlePoolGroups.Remove(poolGroup);
-                }
-            }
+                    var poolGroup = _idlePoolGroups[i];
 
-            _lock.EnterWriteLock();
+                    if (!poolGroup.Clear())
+                    {
+                        _idlePoolGroups.Remove(poolGroup);
+                    }
+                }
 
-            try
-            {
                 var activePoolGroups = new Dictionary<string, SqliteConnectionPoolGroup>();
                 foreach (var entry in _poolGroups)
                 {