From fa19879a176c0e64d747d6aa476f69ade7d9c1be Mon Sep 17 00:00:00 2001
From: "Andrey.Kudashkin" <andrey.kudashkin@russianpost.ru>
Date: Sun, 31 Jan 2021 06:34:16 +0300
Subject: [PATCH] 3396-pool-delete-on-pruning: Support for changes #3485

---
 src/Npgsql/NpgsqlConnection.cs  |  9 ---------
 src/Npgsql/NpgsqlEventSource.cs |  8 ++++++++
 src/Npgsql/PoolManager.cs       | 14 +++++++++++++-
 3 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/src/Npgsql/NpgsqlConnection.cs b/src/Npgsql/NpgsqlConnection.cs
index 7467e7de51..0739ac9a5a 100644
--- a/src/Npgsql/NpgsqlConnection.cs
+++ b/src/Npgsql/NpgsqlConnection.cs
@@ -189,15 +189,6 @@ void GetPoolAndSettings()
             var newPool = new ConnectorPool(Settings, canonical);
             _pool = PoolManager.GetOrAdd(canonical, newPool);
 
-            // If the pool we created was the one that ended up being stored we need to increment the appropriate counter.
-            // Avoids a race condition where multiple threads will create a pool but only one will be stored.
-            if (_pool == newPool)
-            {
-                // If the pool we created was the one that ended up being stored we need to increment the appropriate counter.
-                // Avoids a race condition where multiple threads will create a pool but only one will be stored.
-                NpgsqlEventSource.Log.PoolCreated(newPool);
-            }
-
             _pool = PoolManager.GetOrAdd(_connectionString, _pool);
         }
 
diff --git a/src/Npgsql/NpgsqlEventSource.cs b/src/Npgsql/NpgsqlEventSource.cs
index f9355f9108..4e3435d075 100644
--- a/src/Npgsql/NpgsqlEventSource.cs
+++ b/src/Npgsql/NpgsqlEventSource.cs
@@ -89,6 +89,14 @@ internal void PoolCreated(ConnectorPool pool)
             }
         }
 
+        internal void PoolDeleted(ConnectorPool pool)
+        {
+            lock (_poolsLock)
+            {
+                _pools.Remove(pool);
+            }
+        }
+
         internal void MultiplexingBatchSent(int numCommands, int waits, Stopwatch stopwatch)
         {
             // TODO: CAS loop instead of 4 separate interlocked operations?
diff --git a/src/Npgsql/PoolManager.cs b/src/Npgsql/PoolManager.cs
index 21bd0b977c..b63a161bf4 100644
--- a/src/Npgsql/PoolManager.cs
+++ b/src/Npgsql/PoolManager.cs
@@ -76,6 +76,9 @@ internal static ConnectorPool GetOrAdd(string key, ConnectorPool pool)
                 _pools[_nextSlot].Key = key;
                 _pools[_nextSlot].Pool = pool;
                 Interlocked.Increment(ref _nextSlot);
+
+                NpgsqlEventSource.Log.PoolCreated(pool);
+
                 return pool;
             }
         }
@@ -110,7 +113,9 @@ internal static void Delete(ConnectorPool pool)
 
                 Interlocked.Decrement(ref _nextSlot);
                 _pools = newPools;
-            }    
+
+                NpgsqlEventSource.Log.PoolDeleted(pool);
+            }
         }
 
         internal static void Clear(string connString)
@@ -151,6 +156,13 @@ internal static void Reset()
             lock (Lock)
             {
                 ClearAll();
+                var pools = _pools;
+                foreach (var (_, pool) in pools)
+                {
+                    if (pool != null)
+                        NpgsqlEventSource.Log.PoolDeleted(pool);
+                }
+                
                 _pools = new (string, ConnectorPool)[InitialPoolsSize];
                 _nextSlot = 0;
             }