[Python-checkins] python/dist/src/Misc NEWS, 1.831.4.156, 1.831.4.157

Sun Oct 31 02:13:39 CEST 2004

Update of /cvsroot/python/python/dist/src/Misc
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv2582/Misc
Modified Files:
 Tag: release23-maint
	NEWS 
Log Message:
SF 1055820: weakref callback vs gc vs threads
In cyclic gc, clear all weakrefs to unreachable objects before allowing any
Python code (weakref callbacks or __del__ methods) to run.
This is a critical bugfix, affecting all versions of Python since weakrefs
were introduced.
Index: NEWS
===================================================================
RCS file: /cvsroot/python/python/dist/src/Misc/NEWS,v
retrieving revision 1.831.4.156
retrieving revision 1.831.4.157
diff -u -d -r1.831.4.156 -r1.831.4.157

--- NEWS	20 Oct 2004 11:55:54 -0000	1.831.4.156
+++ NEWS	31 Oct 2004 00:13:05 -0000	1.831.4.157
@@ -12,6 +12,17 @@
 Core and builtins
 -----------------
 
+- Bug #1055820 Cyclic garbage collection was not protecting against that
+ calling a live weakref to a piece of cyclic trash could resurrect an
+ insane mutation of the trash if any Python code ran during gc (via
+ running a dead object's __del__ method, running another callback on a
+ weakref to a dead object, or via any Python code run in any other thread
+ that managed to obtain the GIL while a __del__ or callback was running
+ in the thread doing gc). The most likely symptom was "impossible"
+ ``AttributeEror`` exceptions, appearing seemingly at random, on weakly
+ referenced objects. The cure was to clear all weakrefs to unreachable
+ objects before allowing any callbacks to run.
+
 - Bug #951851: Python crashed when reading import table of certain
 Windows DLLs
 
@@ -88,7 +99,7 @@
 - Bug #679953: zipfile can now handle file sizes over 2 GB. Previously the
 compressed and uncompressed file sizes were being stored as signed longs
 instead of unsigned as the ZIP spec specifies.
- 
+
 - Bug #981530: Fix UnboundLocalError in shutil.rmtree(). This affects
 the documented behavior: the function passed to the onerror()
 handler can now also be os.listdir.
@@ -134,7 +145,7 @@
 
 - Bug #1034496: Use -h instead of -soname for Solaris compatibility.
 
-- Patch #973204: Use -rpath instead of -R for runtime_library_dirs 
+- Patch #973204: Use -rpath instead of -R for runtime_library_dirs
 on Irix and True64.
 
 - Bug #978645: Modules/getpath.c now builds properly under --disable-framework
