Add asyncio.TimeoutError as an exit exception

Added ``asyncio.exceptions.TimeoutError``,
``asyncio.exceptions.CancelledError`` as so-called "exit exceptions", a
class of exceptions that include things like ``GreenletExit`` and
``KeyboardInterrupt``, which are considered to be events that warrant
considering a DBAPI connection to be in an unusable state where it should
be recycled.

Fixes: #6592
Change-Id: Idcfa7aaa2d7660838b907388db9c6457afa6edbd

1 files changed, 4 insertions, 0 deletions

diff --git a/lib/sqlalchemy/util/concurrency.py b/lib/sqlalchemy/util/concurrency.py
index 60db9cfff..463547319 100644
--- a/lib/sqlalchemy/util/concurrency.py
+++ b/lib/sqlalchemy/util/concurrency.py
@@ -12,6 +12,7 @@ if compat.py3k:
         from ._concurrency_py3k import await_only
         from ._concurrency_py3k import await_fallback
         from ._concurrency_py3k import greenlet_spawn
+        from ._concurrency_py3k import is_exit_exception
         from ._concurrency_py3k import AsyncAdaptedLock
         from ._concurrency_py3k import _util_async_run  # noqa F401
         from ._concurrency_py3k import (
@@ -36,6 +37,9 @@ if not have_greenlet:
                 "the greenlet library is required to use this function."
             )
 
+    def is_exit_exception(e):  # noqa F811
+        return not isinstance(e, Exception)
+
     def await_only(thing):  # noqa F811
         _not_implemented()