[Python-checkins] cpython: Issue #19967: Defer the formating of the traceback in asyncio.Future destructor

Sat Dec 21 00:20:41 CET 2013

http://hg.python.org/cpython/rev/06ed1691efdc
changeset: 88104:06ed1691efdc
user: Victor Stinner <victor.stinner at gmail.com>
date: Sat Dec 21 00:19:33 2013 +0100
summary:
 Issue #19967: Defer the formating of the traceback in asyncio.Future destructor
files:
 Lib/asyncio/futures.py | 25 ++++++++++++++-----------
 1 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/Lib/asyncio/futures.py b/Lib/asyncio/futures.py
--- a/Lib/asyncio/futures.py
+++ b/Lib/asyncio/futures.py
@@ -131,8 +131,8 @@
 
 _blocking = False # proper use of future (yield vs yield from)
 
- _traceback = None # Used for Python 3.4 and later
- _tb_logger = None # Used for Python 3.3 only
+ _log_traceback = False # Used for Python 3.4 and later
+ _tb_logger = None # Used for Python 3.3 only
 
 def __init__(self, *, loop=None):
 """Initialize the future.
@@ -168,9 +168,13 @@
 
 if _PY34:
 def __del__(self):
- if self._traceback is not None:
- logger.error('Future/Task exception was never retrieved:\n%s',
- ''.join(self._traceback))
+ if not self._log_traceback:
+ # set_exception() was not called, or result() or exception()
+ # has consumed the exception
+ return
+ exc = self._exception
+ logger.error('Future/Task exception was never retrieved:',
+ exc_info=(exc.__class__, exc, exc.__traceback__))
 
 def cancel(self):
 """Cancel the future and schedule callbacks.
@@ -224,10 +228,10 @@
 raise CancelledError
 if self._state != _FINISHED:
 raise InvalidStateError('Result is not ready.')
- self._traceback = None
+ self._log_traceback = False
 if self._tb_logger is not None:
 self._tb_logger.clear()
- self._tb_logger = None
+ self._tb_logger = None
 if self._exception is not None:
 raise self._exception
 return self._result
@@ -244,10 +248,10 @@
 raise CancelledError
 if self._state != _FINISHED:
 raise InvalidStateError('Exception is not set.')
- self._traceback = None
+ self._log_traceback = False
 if self._tb_logger is not None:
 self._tb_logger.clear()
- self._tb_logger = None
+ self._tb_logger = None
 return self._exception
 
 def add_done_callback(self, fn):
@@ -301,8 +305,7 @@
 self._state = _FINISHED
 self._schedule_callbacks()
 if _PY34:
- self._traceback = traceback.format_exception(
- exception.__class__, exception, exception.__traceback__)
+ self._log_traceback = True
 else:
 self._tb_logger = _TracebackLogger(exception)
 # Arrange for the logger to be activated after all callbacks
-- 
Repository URL: http://hg.python.org/cpython
