[Python-checkins] bpo-41503: Fix race between setTarget and flush in logging.handlers.MemoryHandler (GH-21765)
Irit Katriel
webhook-mailer at python.org
Sun Aug 16 11:10:22 EDT 2020
https://github.com/python/cpython/commit/2353d77fad7ed9d11d8a4d66b5dd1306cdb94125
commit: 2353d77fad7ed9d11d8a4d66b5dd1306cdb94125
branch: master
author: Irit Katriel <iritkatriel at yahoo.com>
committer: GitHub <noreply at github.com>
date: 2020-08-16T16:10:13+01:00
summary:
bpo-41503: Fix race between setTarget and flush in logging.handlers.MemoryHandler (GH-21765)
files:
A Misc/NEWS.d/next/Library/2020-08-07-15-18-16.bpo-41503.IYftcu.rst
M Lib/logging/handlers.py
M Lib/test/test_logging.py
diff --git a/Lib/logging/handlers.py b/Lib/logging/handlers.py
index 4a120e9f1ec48..867ef4ebc7600 100644
--- a/Lib/logging/handlers.py
+++ b/Lib/logging/handlers.py
@@ -1324,7 +1324,11 @@ def setTarget(self, target):
"""
Set the target handler for this handler.
"""
- self.target = target
+ self.acquire()
+ try:
+ self.target = target
+ finally:
+ self.release()
def flush(self):
"""
diff --git a/Lib/test/test_logging.py b/Lib/test/test_logging.py
index eb5b926908a19..d8b3727eb1185 100644
--- a/Lib/test/test_logging.py
+++ b/Lib/test/test_logging.py
@@ -1160,6 +1160,27 @@ def test_flush_on_close(self):
# assert that no new lines have been added
self.assert_log_lines(lines) # no change
+ def test_race_between_set_target_and_flush(self):
+ class MockRaceConditionHandler:
+ def __init__(self, mem_hdlr):
+ self.mem_hdlr = mem_hdlr
+
+ def removeTarget(self):
+ self.mem_hdlr.setTarget(None)
+
+ def handle(self, msg):
+ t = threading.Thread(target=self.removeTarget)
+ t.daemon = True
+ t.start()
+
+ target = MockRaceConditionHandler(self.mem_hdlr)
+ self.mem_hdlr.setTarget(target)
+
+ for _ in range(10):
+ time.sleep(0.005)
+ self.mem_logger.info("not flushed")
+ self.mem_logger.warning("flushed")
+
class ExceptionFormatter(logging.Formatter):
"""A special exception formatter."""
diff --git a/Misc/NEWS.d/next/Library/2020-08-07-15-18-16.bpo-41503.IYftcu.rst b/Misc/NEWS.d/next/Library/2020-08-07-15-18-16.bpo-41503.IYftcu.rst
new file mode 100644
index 0000000000000..c34996d881937
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-08-07-15-18-16.bpo-41503.IYftcu.rst
@@ -0,0 +1 @@
+Fixed a race between setTarget and flush in logging.handlers.MemoryHandler.
\ No newline at end of file
More information about the Python-checkins
mailing list