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bpo-32751: Wait for task cancel in asyncio.wait_for() when timeout <=… · python/cpython@c517fc7

3 files changed

lines changed

Original file line numberDiff line numberDiff line change

@@ -445,8 +445,13 @@ async def wait_for(fut, timeout, *, loop=None):

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if fut.done():

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return fut.result()

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448-

fut.cancel()

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raise exceptions.TimeoutError()

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await _cancel_and_wait(fut, loop=loop)

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try:

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fut.result()

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except exceptions.CancelledError as exc:

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raise exceptions.TimeoutError() from exc

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else:

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raise exceptions.TimeoutError()

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waiter = loop.create_future()

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timeout_handle = loop.call_later(timeout, _release_waiter, waiter)

Original file line numberDiff line numberDiff line change

@@ -1131,6 +1131,9 @@ async def inner():

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nonlocal task_done

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try:

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await asyncio.sleep(0.2)

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except asyncio.CancelledError:

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await asyncio.sleep(_EPSILON)

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raise

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finally:

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task_done = True

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@@ -1145,6 +1148,34 @@ async def inner():

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chained = cm.exception.__context__

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self.assertEqual(type(chained), asyncio.CancelledError)

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def test_wait_for_waits_for_task_cancellation_w_timeout_0(self):

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loop = asyncio.new_event_loop()

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self.addCleanup(loop.close)

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task_done = False

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async def foo():

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async def inner():

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nonlocal task_done

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try:

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await asyncio.sleep(10)

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except asyncio.CancelledError:

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await asyncio.sleep(_EPSILON)

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raise

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finally:

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task_done = True

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inner_task = self.new_task(loop, inner())

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await asyncio.sleep(_EPSILON)

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await asyncio.wait_for(inner_task, timeout=0)

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with self.assertRaises(asyncio.TimeoutError) as cm:

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loop.run_until_complete(foo())

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self.assertTrue(task_done)

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chained = cm.exception.__context__

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self.assertEqual(type(chained), asyncio.CancelledError)

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def test_wait_for_reraises_exception_during_cancellation(self):

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loop = asyncio.new_event_loop()

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self.addCleanup(loop.close)

Original file line numberDiff line numberDiff line change

@@ -0,0 +1,3 @@

1+

When cancelling the task due to a timeout, :meth:`asyncio.wait_for` will now

2+

wait until the cancellation is complete also in the case when *timeout* is

3+

<= 0, like it does with positive timeouts.