AsynchronousTask: don't wait for exit status

Synchronous waiting for status is not supported, since it would be
vulnerable to hitting the recursion limit when a large number of tasks
need to be terminated simultaneously, like in bug #402335.

1 files changed, 11 insertions, 4 deletions

diff --git a/pym/_emerge/SequentialTaskQueue.py b/pym/_emerge/SequentialTaskQueue.py
index 3cd56d2d6..ebff430e3 100644
--- a/pym/_emerge/SequentialTaskQueue.py
+++ b/pym/_emerge/SequentialTaskQueue.py
@@ -55,13 +55,20 @@ class SequentialTaskQueue(SlotObject):
 			self.schedule()
 
 	def clear(self):
+		"""
+		Clear the task queue and asynchronously terminate any running tasks.
+		"""
 		self._task_queue.clear()
-		running_tasks = self.running_tasks
-		while running_tasks:
-			task = running_tasks.pop()
-			task.removeExitListener(self._task_exit)
+		for task in list(self.running_tasks):
 			task.cancel()
 
+	def wait(self):
+		"""
+		Synchronously wait for all running tasks to exit.
+		"""
+		while self.running_tasks:
+			next(iter(self.running_tasks)).wait()
+
 	def __bool__(self):
 		return bool(self._task_queue or self.running_tasks)