[patch] AsynchronousTask: disable event loop recursion

0001-AsynchronousTask-disable-event-loop-recursion-bug-65.patch (text/plain), 2.04 KB, created by Zac Medico on 2018-04-26 10:01:33 UTC

From 3bd2154ced96d5e4f0214d47fc8f981b7a55fb26 Mon Sep 17 00:00:00 2001
From: Zac Medico <[e-mail]>
Date: Thu, 26 Apr 2018 02:51:43 -0700
Subject: [PATCH] AsynchronousTask: disable event loop recursion (bug 653856)

Make the wait() and _async_wait() methods raise InvalidStateError
when the event loop is running and the returncode is not available,
since these cases would trigger event loop recursion.

Bug: https://bugs.gentoo.org/653856
---
 pym/_emerge/AsynchronousTask.py | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/pym/_emerge/AsynchronousTask.py b/pym/_emerge/AsynchronousTask.py
index 7d2e6253b..5cc6d3b7d 100644
--- a/pym/_emerge/AsynchronousTask.py
+++ b/pym/_emerge/AsynchronousTask.py
@@ -4,6 +4,7 @@
 import signal
 
 from portage import os
+from portage.util.futures import asyncio
 from portage.util.SlotObject import SlotObject
 
 class AsynchronousTask(SlotObject):
@@ -17,8 +18,7 @@ class AsynchronousTask(SlotObject):
 	"""
 
 	__slots__ = ("background", "cancelled", "returncode", "scheduler") + \
-		("_exit_listeners", "_exit_listener_stack", "_start_listeners",
-		"_waiting")
+		("_exit_listeners", "_exit_listener_stack", "_start_listeners")
 
 	_cancelled_returncode = - signal.SIGINT
 
@@ -71,12 +71,9 @@ class AsynchronousTask(SlotObject):
 		Deprecated. Use async_wait() instead.
 		"""
 		if self.returncode is None:
-			if not self._waiting:
-				self._waiting = True
-				try:
-					self._wait()
-				finally:
-					self._waiting = False
+			if self.scheduler.is_running():
+				raise asyncio.InvalidStateError('Result is not ready.')
+			self.scheduler.run_until_complete(self.async_wait())
 		self._wait_hook()
 		return self.returncode
 
@@ -91,6 +88,8 @@ class AsynchronousTask(SlotObject):
 		loop recursion (or stack overflow) that synchronous calling of
 		exit listeners can cause. This method is thread-safe.
 		"""
+		if self.returncode is None:
+			raise asyncio.InvalidStateError('Result is not ready.')
 		self.scheduler.idle_add(self._async_wait_cb)
 
 	def _async_wait_cb(self):
-- 
2.13.6