When a thread touches such an object for the first time, a new thread-local __dict__ is created,
and the __init__ method is run.
But a thread switch can occur here; if the other thread touches the same object, it installs another
__dict__; when the first thread resumes, it updates the dictionary of the second...
This is the deep cause of the failures in test_multiprocessing involving "managers" objects.
Backport of r64601.
Add some asserts. In sysmodule, I think these were to try to silence
some warnings from Klokwork. They verify the assumptions of the format
of svn version output.
The assert in the thread module helped debug a problem on HP-UX.
Heavily revised, comprising revisions:
46640 - original trunk revision (backed out in r46655)
46647 - markup fix (backed out in r46655)
46692:46918 merged from branch aimacintyre-sf1454481
branch tested on buildbots (Windows buildbots had problems
not related to these changes).
46640 Patch #1454481: Make thread stack size runtime tunable.
46647 Markup fix
The first is causing many buildbots to fail test runs, and there
are multiple causes with seemingly no immediate prospects for
repairing them. See python-dev discussion.
Note that a branch can (and should) be created for resolving these
problems, like
svn copy svn+ssh://svn.python.org/python/trunk -r46640 svn+ssh://svn.python.org/python/branches/NEW_BRANCH
followed by merging rev 46647 to the new branch.
discussion.
There are two places of documentation that still mention __context__:
Doc/lib/libstdtypes.tex -- I wasn't quite sure how to rewrite that without
spending a whole lot of time thinking about it; and whatsnew, which Andrew
usually likes to change himself.
Anyway, this is the changes to the with-statement
so that __exit__ must return a true value in order
for a pending exception to be ignored.
The PEP (343) is already updated.
- New semantics for __exit__() -- it must re-raise the exception
if type is not None; the with-statement itself doesn't do this.
(See the updated PEP for motivation.)
- Added context managers to:
- file
- thread.LockType
- threading.{Lock,RLock,Condition,Semaphore,BoundedSemaphore}
- decimal.Context
- Added contextlib.py, which defines @contextmanager, nested(), closing().
- Unit tests all around; bot no docs yet.
