Avoid potential deadlock in getaddrinfo #848
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Test failed to create a sender thread due to a name clash between sender the thread and the sender callback parameter. Sender thread produces lots of expected errors (of "Connection refused" kind), so we also silence errors from the client library.
time.sleep(0) allows python to switch to another thread, allowing main thread to progress through stages quicker, while still being able to catch deadlocks from getaddrinfo or improper locking in fork hooks.
Try sending metric from the child process. This makes sure that all locks are still in a serviceable state after the fork.
getaddrinfo may use an internal lock that, in case of a concurrent fork, may be left in locked state and cause child process to deadlock.
vickenty
added
the
changelog/Fixed
pre_fork is now mutually exclusive with get_socket() until post_fork is called, so the sequence of events that the test was testing is no longer possible.
carlosroman
previously approved these changes
Aug 23, 2024
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This issue has been automatically marked as stale because it has not had activity in the last 30 days. |
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What does this PR do?
Avoid deadlock in the child process in getaddrinfo if the application forks while a thread is trying to create a socket.
Description of the Change
Acquire socket lock before forking to prevent the client library from calling getaddrinfo at the same time.
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changelog/label attached. If applicable it should have thebackward-incompatiblelabel attached.do-not-merge/label attached.kind/andseverity/labels attached at least.