ForkExecutor: use async_start method

Also, fix AsynchronousTask.async_start to handle cancellation of the
_async_start coroutine, ensuring that start and exit listeners are
notified in this case (otherwise RetryForkExecutorTestCase will hang).

Signed-off-by: Zac Medico <zmedico@gentoo.org>

1 files changed, 13 insertions, 2 deletions

diff --git a/lib/_emerge/AsynchronousTask.py b/lib/_emerge/AsynchronousTask.py
index d1e23cdf1..1e9e177cb 100644
--- a/lib/_emerge/AsynchronousTask.py
+++ b/lib/_emerge/AsynchronousTask.py
@@ -25,8 +25,19 @@ class AsynchronousTask(SlotObject):
 
 	@coroutine
 	def async_start(self):
-		yield self._async_start()
-		self._start_hook()
+		try:
+			if self._was_cancelled():
+				raise asyncio.CancelledError
+			yield self._async_start()
+			if self._was_cancelled():
+				raise asyncio.CancelledError
+		except asyncio.CancelledError:
+			self.cancel()
+			self._was_cancelled()
+			self._async_wait()
+			raise
+		finally:
+			self._start_hook()
 
 	@coroutine
 	def _async_start(self):