gh-110167: Fix test_socket deadlock in doCleanups() (#110416)

Fix a deadlock in test_socket when server fails with a timeout but
the client is still running in its thread. Don't hold a lock to call
cleanup functions in doCleanups(). One of the cleanup function waits
until the client completes, whereas the client could deadlock if it
called addCleanup() in such situation.

doCleanups() is called when the server completed, but the client can
still be running in its thread especially if the server failed with a
timeout. Don't put a lock on doCleanups() to prevent deadlock between
addCleanup() called in the client and doCleanups() waiting for
self.done.wait of ThreadableTest._setUp().
This commit is contained in:
Victor Stinner 2023-10-05 20:53:03 +02:00 committed by GitHub
parent 1f3af03f83
commit 318f5df271
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 12 additions and 5 deletions

View File

@ -218,8 +218,13 @@ class SocketUDPLITETest(SocketUDPTest):
class ThreadSafeCleanupTestCase:
"""Subclass of unittest.TestCase with thread-safe cleanup methods.
This subclass protects the addCleanup() and doCleanups() methods
with a recursive lock.
This subclass protects the addCleanup() method with a recursive lock.
doCleanups() is called when the server completed, but the client can still
be running in its thread especially if the server failed with a timeout.
Don't put a lock on doCleanups() to prevent deadlock between addCleanup()
called in the client and doCleanups() waiting for self.done.wait of
ThreadableTest._setUp() (gh-110167)
"""
def __init__(self, *args, **kwargs):
@ -230,9 +235,6 @@ class ThreadSafeCleanupTestCase:
with self._cleanup_lock:
return super().addCleanup(*args, **kwargs)
def doCleanups(self, *args, **kwargs):
with self._cleanup_lock:
return super().doCleanups(*args, **kwargs)
class SocketCANTest(unittest.TestCase):

View File

@ -0,0 +1,5 @@
Fix a deadlock in test_socket when server fails with a timeout but the
client is still running in its thread. Don't hold a lock to call cleanup
functions in doCleanups(). One of the cleanup function waits until the
client completes, whereas the client could deadlock if it called
addCleanup() in such situation. Patch by Victor Stinner.