[Python-checkins] cpython (3.4): asyncio: sync with Tulip

Mon Jun 30 14:41:00 CEST 2014

http://hg.python.org/cpython/rev/defd09a5339a
changeset: 91483:defd09a5339a
branch: 3.4
parent: 91480:4c8fc852244a
user: Victor Stinner <victor.stinner at gmail.com>
date: Mon Jun 30 14:39:11 2014 +0200
summary:
 asyncio: sync with Tulip
- Sort imports
- Simplify/optimize iscoroutine(). Inline inspect.isgenerator(obj): replace it
 with isinstance(obj, types.GeneratorType)
- CoroWrapper: check at runtime if Python has the yield-from bug #21209. If
 Python has the bug, check if CoroWrapper.send() was called by yield-from to
 decide if parameters must be unpacked or not.
- Fix "Task was destroyed but it is pending!" warning in
 test_task_source_traceback()
files:
 Lib/asyncio/base_events.py | 4 +-
 Lib/asyncio/coroutines.py | 57 ++++++++++++++--
 Lib/test/test_asyncio/test_tasks.py | 1 +
 3 files changed, 52 insertions(+), 10 deletions(-)

diff --git a/Lib/asyncio/base_events.py b/Lib/asyncio/base_events.py
--- a/Lib/asyncio/base_events.py
+++ b/Lib/asyncio/base_events.py
@@ -19,11 +19,11 @@
 import heapq
 import inspect
 import logging
+import os
 import socket
 import subprocess
+import time
 import traceback
-import time
-import os
 import sys
 
 from . import coroutines
diff --git a/Lib/asyncio/coroutines.py b/Lib/asyncio/coroutines.py
--- a/Lib/asyncio/coroutines.py
+++ b/Lib/asyncio/coroutines.py
@@ -3,14 +3,20 @@
 
 import functools
 import inspect
+import opcode
 import os
 import sys
 import traceback
+import types
 
 from . import events
 from . import futures
 from .log import logger
 
+
+# Opcode of "yield from" instruction
+_YIELD_FROM = opcode.opmap['YIELD_FROM']
+
 # If you set _DEBUG to true, @coroutine will wrap the resulting
 # generator objects in a CoroWrapper instance (defined below). That
 # instance will log a message when the generator is never iterated
@@ -25,6 +31,31 @@
 
 _PY35 = (sys.version_info >= (3, 5))
 
+
+# Check for CPython issue #21209
+def has_yield_from_bug():
+ class MyGen:
+ def __init__(self):
+ self.send_args = None
+ def __iter__(self):
+ return self
+ def __next__(self):
+ return 42
+ def send(self, *what):
+ self.send_args = what
+ return None
+ def yield_from_gen(gen):
+ yield from gen
+ value = (1, 2, 3)
+ gen = MyGen()
+ coro = yield_from_gen(gen)
+ next(coro)
+ coro.send(value)
+ return gen.send_args != (value,)
+_YIELD_FROM_BUG = has_yield_from_bug()
+del has_yield_from_bug
+
+
 class CoroWrapper:
 # Wrapper for coroutine in _DEBUG mode.
 
@@ -40,13 +71,21 @@
 def __next__(self):
 return next(self.gen)
 
- def send(self, *value):
- # We use `*value` because of a bug in CPythons prior
- # to 3.4.1. See issue #21209 and test_yield_from_corowrapper
- # for details. This workaround should be removed in 3.5.0.
- if len(value) == 1:
- value = value[0]
- return self.gen.send(value)
+ if _YIELD_FROM_BUG:
+ # For for CPython issue #21209: using "yield from" and a custom
+ # generator, generator.send(tuple) unpacks the tuple instead of passing
+ # the tuple unchanged. Check if the caller is a generator using "yield
+ # from" to decide if the parameter should be unpacked or not.
+ def send(self, *value):
+ frame = sys._getframe()
+ caller = frame.f_back
+ assert caller.f_lasti >= 0
+ if caller.f_code.co_code[caller.f_lasti] != _YIELD_FROM:
+ value = value[0]
+ return self.gen.send(value)
+ else:
+ def send(self, value):
+ return self.gen.send(value)
 
 def throw(self, exc):
 return self.gen.throw(exc)
@@ -119,9 +158,11 @@
 return getattr(func, '_is_coroutine', False)
 
 
+_COROUTINE_TYPES = (CoroWrapper, types.GeneratorType)
+
 def iscoroutine(obj):
 """Return True if obj is a coroutine object."""
- return isinstance(obj, CoroWrapper) or inspect.isgenerator(obj)
+ return isinstance(obj, _COROUTINE_TYPES)
 
 
 def _format_coroutine(coro):
diff --git a/Lib/test/test_asyncio/test_tasks.py b/Lib/test/test_asyncio/test_tasks.py
--- a/Lib/test/test_asyncio/test_tasks.py
+++ b/Lib/test/test_asyncio/test_tasks.py
@@ -1621,6 +1621,7 @@
 (__file__,
 lineno,
 'test_task_source_traceback'))
+ self.loop.run_until_complete(task)
 
 
 class GatherTestsBase:
-- 
Repository URL: http://hg.python.org/cpython
