* Use try/except ImportError or test_support.import_module() to import thread
and threading modules
* Add @unittest.skipUnless(threading, ...) to testcases using threads
issues that crop up from time to time, but this change seems to have been
pretty stable (no spurious warnings) for about a week.
Other modules which use threads may require similar use of
threading_setup/threading_cleanup from test_support.
A possibility to deadlock (on the hidden import lock) was created here
in 2.3, seemingly when tempfile.py started to call functions in
random.py. The cure is "the usual": don't spawn threads as a side
effect of importing, when the spawned threads themselves do imports
(directly or indirectly), and the code that spawned the threads is
waiting for the threads to finish (they can't finish, because they're
waiting for the import lock the spawner still holds). Worming around
this is why the "test_main" mechanism was introduced in regrest, so
it's a straightforward fix.
NOT a bugfix candidate; the problem was introduced in 2.3.
imports e.g. test_support must do so using an absolute package name
such as "import test.test_support" or "from test import test_support".
This also updates the README in Lib/test, and gets rid of the
duplicate data dirctory in Lib/test/data (replaced by
Lib/email/test/data).
Now Tim and Jack can have at it. :)
pid across threads (but in that case, it's still the same process, and so
still sharing the "template" cache in tempfile.py). Repaired that, and
added a new std test.
On Linux, someone please run that standalone with more files and/or more
threads; e.g.,
python lib/test/test_threadedtempfile.py -f 1000 -t 10
to run with 10 threads each creating (and deleting) 1000 temp files.
Ezio Melotti
Victor Stinner
Tim Peters
Collin Winter
Neal Norwitz
Barry Warsaw
Guido van Rossum