Charles-François Natali <neolo...@free.fr> added the comment:
> Probably because I'm a threading/multiprocessing neophyte :)
That's a very good reason :-)
Here's a version using two multiprocessing events. Note that I use
timeouts for wait() just to avoid being stuck if something goes wrong:
the test now runs in a dozen ms.
By the way, next time you need a duplex communication between two
processes, you can use socketpair(), which returns a pair of connected
sockets.
----------
Added file: http://bugs.python.org/file24049/test_mailbox_evt.diff
_______________________________________
Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue11867>
_______________________________________
diff --git a/Lib/test/test_mailbox.py b/Lib/test/test_mailbox.py
--- a/Lib/test/test_mailbox.py
+++ b/Lib/test/test_mailbox.py
@@ -17,6 +17,10 @@
import fcntl
except ImportError:
pass
+try:
+ import multiprocessing
+except ImportError:
+ multiprocessing = None
class TestBase(unittest.TestCase):
@@ -993,28 +997,36 @@
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.
+ # child
try:
+ # lock the mailbox, and signal the parent it can proceed
self._box.lock()
- time.sleep(2)
+ 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, sleep a bit to give the child time to acquire
- # the lock.
- time.sleep(0.5)
+ # 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)
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
