From 0ef66202e1e91cc6330d81980c3a78dc38676bb9 Mon Sep 17 00:00:00 2001
From: Ingmar Steen <i.steen@nrc.nl>
Date: Fri, 30 Sep 2022 17:28:17 +0200
Subject: [PATCH 1/2] Close connection when _fill_free_pool is cancelled.

Cancelling _fill_free_pool before a new connection is added to
self._free prevents it from being cleaned up which causes a
lingering connection and eventually the postgresql server running
out of sockets.
---
 aiopg/pool.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/aiopg/pool.py b/aiopg/pool.py
index 4d6015c6..9d0cf5e7 100644
--- a/aiopg/pool.py
+++ b/aiopg/pool.py
@@ -347,6 +347,9 @@ async def _fill_free_pool(self, override_min: bool) -> None:
                 # raise exception if pool is closing
                 self._free.append(conn)
                 self._cond.notify()
+            except asyncio.CancelledError:
+                conn.close()
+                raise
             finally:
                 self._acquiring -= 1
         if self._free:
@@ -369,6 +372,9 @@ async def _fill_free_pool(self, override_min: bool) -> None:
                 # raise exception if pool is closing
                 self._free.append(conn)
                 self._cond.notify()
+            except asyncio.CancelledError:
+                conn.close()
+                raise
             finally:
                 self._acquiring -= 1
 

From 1f39c7c36b0e8376f6d55f4c14f12352dec9b6c3 Mon Sep 17 00:00:00 2001
From: Ingmar Steen <i.steen@nrc.nl>
Date: Fri, 30 Sep 2022 17:35:45 +0200
Subject: [PATCH 2/2] Guard against the unlikely event conn will not be set.

---
 aiopg/pool.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/aiopg/pool.py b/aiopg/pool.py
index 9d0cf5e7..1b6e58c0 100644
--- a/aiopg/pool.py
+++ b/aiopg/pool.py
@@ -332,6 +332,7 @@ async def _fill_free_pool(self, override_min: bool) -> None:
 
         while self.size < self.minsize:
             self._acquiring += 1
+            conn = None
             try:
                 conn = await connect(
                     self._dsn,
@@ -348,7 +349,8 @@ async def _fill_free_pool(self, override_min: bool) -> None:
                 self._free.append(conn)
                 self._cond.notify()
             except asyncio.CancelledError:
-                conn.close()
+                if conn is not None:
+                    conn.close()
                 raise
             finally:
                 self._acquiring -= 1
@@ -357,6 +359,7 @@ async def _fill_free_pool(self, override_min: bool) -> None:
 
         if override_min and (not self.maxsize or self.size < self.maxsize):
             self._acquiring += 1
+            conn = None
             try:
                 conn = await connect(
                     self._dsn,
@@ -373,7 +376,8 @@ async def _fill_free_pool(self, override_min: bool) -> None:
                 self._free.append(conn)
                 self._cond.notify()
             except asyncio.CancelledError:
-                conn.close()
+                if conn is not None:
+                    conn.close()
                 raise
             finally:
                 self._acquiring -= 1