diff options
| -rw-r--r-- | Lib/logging/handlers.py | 6 | ||||
| -rw-r--r-- | Lib/test/test_logging.py | 21 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2020-08-07-15-18-16.bpo-41503.IYftcu.rst | 1 |
3 files changed, 27 insertions, 1 deletions
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 @@ class MemoryHandler(BufferingHandler): """ 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 eb5b926..d8b3727 100644 --- a/Lib/test/test_logging.py +++ b/Lib/test/test_logging.py @@ -1160,6 +1160,27 @@ class MemoryHandlerTest(BaseTest): # 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 0000000..c34996d --- /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.
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