[Python-checkins] cpython (3.4): asyncio: Error if awaiting in parallel on the same coroutine

Wed Nov 18 12:40:46 EST 2015

https://hg.python.org/cpython/rev/89d66f912671
changeset: 99201:89d66f912671
branch: 3.4
parent: 99197:660bdfaada64
user: Yury Selivanov <yselivanov at sprymix.com>
date: Wed Nov 18 12:39:45 2015 -0500
summary:
 asyncio: Error if awaiting in parallel on the same coroutine
This change won't do anything in CPython 3.4
See https://github.com/python/asyncio/pull/293 for details.
files:
 Lib/asyncio/coroutines.py | 8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/Lib/asyncio/coroutines.py b/Lib/asyncio/coroutines.py
--- a/Lib/asyncio/coroutines.py
+++ b/Lib/asyncio/coroutines.py
@@ -140,7 +140,13 @@
 
 if compat.PY35:
 
- __await__ = __iter__ # make compatible with 'await' expression
+ def __await__(self):
+ cr_await = getattr(self.gen, 'cr_await', None)
+ if cr_await is not None:
+ raise RuntimeError(
+ "Cannot await on coroutine {!r} while it's "
+ "awaiting for {!r}".format(self.gen, cr_await))
+ return self
 
 @property
 def gi_yieldfrom(self):
-- 
Repository URL: https://hg.python.org/cpython
