diff options
Diffstat (limited to 'Lib/test/test_mailbox.py')
| -rw-r--r-- | Lib/test/test_mailbox.py | 40 |
1 files changed, 27 insertions, 13 deletions
diff --git a/Lib/test/test_mailbox.py b/Lib/test/test_mailbox.py index 75e0a8d4f6..9fdcbde0cc 100644 --- a/Lib/test/test_mailbox.py +++ b/Lib/test/test_mailbox.py @@ -15,6 +15,10 @@ try: import fcntl except ImportError: pass +try: + import multiprocessing +except ImportError: + multiprocessing = None # Silence Py3k warning rfc822 = test_support.import_module('rfc822', deprecated=True) @@ -865,26 +869,36 @@ class _TestMboxMMDF(TestMailbox): self.assertEqual(contents, f.read()) self._box = self._factory(self._path) + @unittest.skipUnless(hasattr(os, 'fork'), "Test needs fork().") + @unittest.skipUnless(multiprocessing, "Test needs multiprocessing.") def test_lock_conflict(self): - # Fork off a subprocess that will lock the file for 2 seconds, - # unlock it, and then exit. - if not hasattr(os, 'fork'): - return + # Fork off a child process that will lock the mailbox temporarily, + # unlock it and exit. + ready = multiprocessing.Event() + done = multiprocessing.Event() + pid = os.fork() if pid == 0: - # In the child, lock the mailbox. - self._box.lock() - time.sleep(2) - self._box.unlock() - os._exit(0) - - # In the parent, sleep a bit to give the child time to acquire - # the lock. - time.sleep(0.5) + # child + try: + # lock the mailbox, and signal the parent it can proceed + self._box.lock() + ready.set() + + # wait until the parent is done, and unlock the mailbox + done.wait(5) + self._box.unlock() + finally: + os._exit(0) + + # In the parent, wait until the child signals it locked the mailbox. + ready.wait(5) try: self.assertRaises(mailbox.ExternalClashError, self._box.lock) finally: + # Signal the child it can now release the lock and exit. + done.set() # Wait for child to exit. Locking should now succeed. exited_pid, status = os.waitpid(pid, 0) |