commit 2c050e52f1ccf5db03819e4ed70690521d67e9fa
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Sun Aug 16 08:34:27 2020 -0700
committer GitHub <noreply@github.com> Sun Aug 16 08:34:27 2020 -0700
tree 20b2948def6a80d25027051c54bea98dcc99bc00
parent 28bf82661ac9dfaf1b2d0fd0ac98fc0b31cd95bb

[3.9] bpo-41503: Fix race between setTarget and flush in logging.handlers.MemoryHandler (GH-21765) (GH-21897)



(cherry picked from commit 2353d77fad7ed9d11d8a4d66b5dd1306cdb94125)


Co-authored-by: Irit Katriel <iritkatriel@yahoo.com>

Automerge-Triggered-By: @vsajip

Lib/logging/handlers.py

diff --git a/Lib/logging/handlers.py b/Lib/logging/handlers.py
index 4a120e9..867ef4e 100644
--- a/Lib/logging/handlers.py
+++ b/Lib/logging/handlers.py
@@ -1324,7 +1324,11 @@
         """
         Set the target handler for this handler.
         """
-        self.target = target
+        self.acquire()
+        try:
+            self.target = target
+        finally:
+            self.release()
 
     def flush(self):
         """