Fix ConnectionPool deadlock triggered by gc

Garbage collector sometimes are invoked in block of code which acquired ConnectionPool._lock.
This cause deadlock blocking indefinitely whole thread.

Author: jaroslawporada

CHANGES

@@ -55,6 +55,7 @@
     * Fix for Unhandled exception related to self.host with unix socket (#2496)
     * Improve error output for master discovery 
     * Make `ClusterCommandsProtocol` an actual Protocol
+    * Fix ConnectionPool deadlock triggered by gc
 
 * 4.1.3 (Feb 8, 2022)
   * Fix flushdb and flushall (#1926)

redis/connection.py

@@ -1008,7 +1008,7 @@ def __repr__(self) -> (str, str):
         )
 
     def reset(self) -> None:
-        self._lock = threading.Lock()
+        self._lock = threading.RLock()
         self._created_connections = 0
         self._available_connections = []
         self._in_use_connections = set()