Merged revisions 76117 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
........
r76117 | antoine.pitrou | 2009-11-05 14:42:29 +0100 (jeu., 05 nov. 2009) | 5 lines
Issue #7264: Fix a possible deadlock when deallocating thread-local objects
which are part of a reference cycle.
........
diff --git a/Lib/_threading_local.py b/Lib/_threading_local.py
index 4eda630..243d84e 100644
--- a/Lib/_threading_local.py
+++ b/Lib/_threading_local.py
@@ -218,10 +218,12 @@
key = object.__getattribute__(self, '_local__key')
try:
- threads = list(threading.enumerate())
+ # We use the non-locking API since we might already hold the lock
+ # (__del__ can be called at any point by the cyclic GC).
+ threads = threading._enumerate()
except:
- # If enumerate fails, as it seems to do during
- # shutdown, we'll skip cleanup under the assumption
+ # If enumerating the current threads fails, as it seems to do
+ # during shutdown, we'll skip cleanup under the assumption
# that there is nothing to clean up.
return
diff --git a/Lib/threading.py b/Lib/threading.py
index 1182f19..18c28b7 100644
--- a/Lib/threading.py
+++ b/Lib/threading.py
@@ -815,6 +815,10 @@
active_count = activeCount
+def _enumerate():
+ # Same as enumerate(), but without the lock. Internal use only.
+ return _active.values() + _limbo.values()
+
def enumerate():
_active_limbo_lock.acquire()
active = _active.values() + _limbo.values()
diff --git a/Misc/NEWS b/Misc/NEWS
index 7bcad72..71d613b 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -24,6 +24,9 @@
Library
-------
+- Issue #7264: Fix a possible deadlock when deallocating thread-local objects
+ which are part of a reference cycle.
+
- Issue #7249: Methods of io.BytesIO now allow `long` as well as `int`
arguments.