[Python-checkins] r76120 - in python/branches/release31-maint: Lib/_threading_local.py Lib/threading.py Misc/NEWS

Thu Nov 5 14:51:19 CET 2009

Author: antoine.pitrou
Date: Thu Nov 5 14:51:19 2009
New Revision: 76120
Log:
Merged revisions 76119 via svnmerge from 
svn+ssh://pythondev@svn.python.org/python/branches/py3k
................
 r76119 | antoine.pitrou | 2009年11月05日 14:49:14 +0100 (jeu., 05 nov. 2009) | 10 lines
 
 Merged revisions 76117 via svnmerge from 
 svn+ssh://pythondev@svn.python.org/python/trunk
 
 ........
 r76117 | antoine.pitrou | 2009年11月05日 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.
 ........
................
Modified:
 python/branches/release31-maint/ (props changed)
 python/branches/release31-maint/Lib/_threading_local.py
 python/branches/release31-maint/Lib/threading.py
 python/branches/release31-maint/Misc/NEWS
Modified: python/branches/release31-maint/Lib/_threading_local.py
==============================================================================

--- python/branches/release31-maint/Lib/_threading_local.py	(original)
+++ python/branches/release31-maint/Lib/_threading_local.py	Thu Nov 5 14:51:19 2009
@@ -217,10 +217,12 @@
 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
 
Modified: python/branches/release31-maint/Lib/threading.py
==============================================================================
--- python/branches/release31-maint/Lib/threading.py	(original)
+++ python/branches/release31-maint/Lib/threading.py	Thu Nov 5 14:51:19 2009
@@ -798,6 +798,10 @@
 
 activeCount = active_count
 
+def _enumerate():
+ # Same as enumerate(), but without the lock. Internal use only.
+ return list(_active.values()) + list(_limbo.values())
+
 def enumerate():
 with _active_limbo_lock:
 return list(_active.values()) + list(_limbo.values())
Modified: python/branches/release31-maint/Misc/NEWS
==============================================================================
--- python/branches/release31-maint/Misc/NEWS	(original)
+++ python/branches/release31-maint/Misc/NEWS	Thu Nov 5 14:51:19 2009
@@ -40,6 +40,9 @@
 Library
 -------
 
+- Issue #7264: Fix a possible deadlock when deallocating thread-local objects
+ which are part of a reference cycle.
+
 - Issue #6896: mailbox.Maildir now invalidates its internal cache each time
 a modification is done through it. This fixes inconsistencies and test
 failures on systems with slightly bogus mtime behaviour.
