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author | Jake Tesler <jake.tesler@gmail.com> | 2019-11-19 19:50:12 (GMT) |
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committer | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2019-11-19 19:50:12 (GMT) |
commit | c6b20be85c0de6f2355c67ae6e7e578941275cc0 (patch) | |
tree | 1482aa6693e3fa4001a0a77c8fd50fb1a0223f66 /Lib/test/_test_multiprocessing.py | |
parent | 892221bfa04a41cf581f988ba19dc263f557e157 (diff) | |
download | cpython-c6b20be85c0de6f2355c67ae6e7e578941275cc0.zip cpython-c6b20be85c0de6f2355c67ae6e7e578941275cc0.tar.gz cpython-c6b20be85c0de6f2355c67ae6e7e578941275cc0.tar.bz2 |
bpo-38707: Fix for multiprocessing.Process MainThread.native_id (GH-17088)
This PR implements a fix for `multiprocessing.Process` objects; the error occurs when Processes are created using either `fork` or `forkserver` as the `start_method`.
In these instances, the `MainThread` of the newly created `Process` object retains all attributes from its parent's `MainThread` object, including the `native_id` attribute. The resulting behavior is such that the new process' `MainThread` captures an incorrect/outdated `native_id` (the parent's instead of its own).
This change forces the Process object to update its `native_id` attribute during the bootstrap process.
cc @vstinner
https://bugs.python.org/issue38707
Automerge-Triggered-By: @pitrou
Diffstat (limited to 'Lib/test/_test_multiprocessing.py')
-rw-r--r-- | Lib/test/_test_multiprocessing.py | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/Lib/test/_test_multiprocessing.py b/Lib/test/_test_multiprocessing.py index f7bebc6..611291c 100644 --- a/Lib/test/_test_multiprocessing.py +++ b/Lib/test/_test_multiprocessing.py @@ -361,6 +361,28 @@ class _TestProcess(BaseTestCase): self.assertNotIn(p, self.active_children()) close_queue(q) + @unittest.skipUnless(threading._HAVE_THREAD_NATIVE_ID, "needs native_id") + def test_process_mainthread_native_id(self): + if self.TYPE == 'threads': + self.skipTest('test not appropriate for {}'.format(self.TYPE)) + + current_mainthread_native_id = threading.main_thread().native_id + + q = self.Queue(1) + p = self.Process(target=self._test_process_mainthread_native_id, args=(q,)) + p.start() + + child_mainthread_native_id = q.get() + p.join() + close_queue(q) + + self.assertNotEqual(current_mainthread_native_id, child_mainthread_native_id) + + @classmethod + def _test_process_mainthread_native_id(cls, q): + mainthread_native_id = threading.main_thread().native_id + q.put(mainthread_native_id) + @classmethod def _sleep_some(cls): time.sleep(100) |