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Mike Bayer
17f1b30a94
Repaired a regression caused by the fix for 🎫`8419` which caused asyncpg connections to be reset (i.e. transaction ``rollback()`` called) and returned to the pool normally in the case that the connection were not explicitly returned to the connection pool and was instead being intercepted by Python garbage collection, which would fail if the garbage collection operation were being called outside of the asyncio event loop, leading to a large amount of stack trace activity dumped into logging and standard output. The correct behavior is restored, which is that all asyncio connections that are garbage collected due to not being explicitly returned to the connection pool are detached from the pool and discarded, along with a warning, rather than being returned the pool, as they cannot be reliably reset. In the case of asyncpg connections, the asyncpg-specific ``terminate()`` method will be used to end the connection more gracefully within this process as opposed to just dropping it. This change includes a small behavioral change that is hoped to be useful for debugging asyncio applications, where the warning that's emitted in the case of asyncio connections being unexpectedly garbage collected has been made slightly more aggressive by moving it outside of a ``try/except`` block and into a ``finally:`` block, where it will emit unconditionally regardless of whether the detach/termination operation succeeded or not. It will also have the effect that applications or test suites which promote Python warnings to exceptions will see this as a full exception raise, whereas previously it was not possible for this warning to actually propagate as an exception. Applications and test suites which need to tolerate this warning in the interim should adjust the Python warnings filter to allow these warnings to not raise. The behavior for traditional sync connections remains unchanged, that garbage collected connections continue to be returned to the pool normally without emitting a warning. This will likely be changed in a future major release to at least emit a similar warning as is emitted for asyncio drivers, as it is a usage error for pooled connections to be intercepted by garbage collection without being properly returned to the pool. Fixes: #9237 Change-Id: Ib35cfb2e628f2eb2da6d2b65674702556f55603a