From 998c3856c1e922ece806c162858dc587a1e92e02 Mon Sep 17 00:00:00 2001 From: Tian Gao Date: Fri, 3 May 2024 11:45:46 -0700 Subject: gh-83856: Honor atexit for all multiprocessing start methods (GH-114279) Use atexit for all multiprocessing start methods to cleanup. See the GH-114279 PR discussion and related issue for details as to why. --- Lib/multiprocessing/forkserver.py | 4 ++++ Lib/multiprocessing/popen_fork.py | 4 ++++ Lib/multiprocessing/process.py | 7 ++----- Lib/test/_test_multiprocessing.py | 23 ++++++++++++++++++++++ .../2024-01-19-05-40-46.gh-issue-83856.jN5M80.rst | 1 + 5 files changed, 34 insertions(+), 5 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2024-01-19-05-40-46.gh-issue-83856.jN5M80.rst diff --git a/Lib/multiprocessing/forkserver.py b/Lib/multiprocessing/forkserver.py index 4642707..53b8c49 100644 --- a/Lib/multiprocessing/forkserver.py +++ b/Lib/multiprocessing/forkserver.py @@ -1,3 +1,4 @@ +import atexit import errno import os import selectors @@ -271,6 +272,8 @@ def main(listener_fd, alive_r, preload, main_path=None, sys_path=None): selector.close() unused_fds = [alive_r, child_w, sig_r, sig_w] unused_fds.extend(pid_to_fd.values()) + atexit._clear() + atexit.register(util._exit_function) code = _serve_one(child_r, fds, unused_fds, old_handlers) @@ -278,6 +281,7 @@ def main(listener_fd, alive_r, preload, main_path=None, sys_path=None): sys.excepthook(*sys.exc_info()) sys.stderr.flush() finally: + atexit._run_exitfuncs() os._exit(code) else: # Send pid to client process diff --git a/Lib/multiprocessing/popen_fork.py b/Lib/multiprocessing/popen_fork.py index 625981c..a57ef6b 100644 --- a/Lib/multiprocessing/popen_fork.py +++ b/Lib/multiprocessing/popen_fork.py @@ -1,3 +1,4 @@ +import atexit import os import signal @@ -66,10 +67,13 @@ class Popen(object): self.pid = os.fork() if self.pid == 0: try: + atexit._clear() + atexit.register(util._exit_function) os.close(parent_r) os.close(parent_w) code = process_obj._bootstrap(parent_sentinel=child_r) finally: + atexit._run_exitfuncs() os._exit(code) else: os.close(child_w) diff --git a/Lib/multiprocessing/process.py b/Lib/multiprocessing/process.py index 271ba3f..b45f7df 100644 --- a/Lib/multiprocessing/process.py +++ b/Lib/multiprocessing/process.py @@ -310,11 +310,8 @@ class BaseProcess(object): # _run_after_forkers() is executed del old_process util.info('child process calling self.run()') - try: - self.run() - exitcode = 0 - finally: - util._exit_function() + self.run() + exitcode = 0 except SystemExit as e: if e.code is None: exitcode = 0 diff --git a/Lib/test/_test_multiprocessing.py b/Lib/test/_test_multiprocessing.py index 5fc4181..46afdfc 100644 --- a/Lib/test/_test_multiprocessing.py +++ b/Lib/test/_test_multiprocessing.py @@ -6161,6 +6161,29 @@ class TestNamedResource(unittest.TestCase): self.assertFalse(err, msg=err.decode('utf-8')) +class _TestAtExit(BaseTestCase): + + ALLOWED_TYPES = ('processes',) + + @classmethod + def _write_file_at_exit(self, output_path): + import atexit + def exit_handler(): + with open(output_path, 'w') as f: + f.write("deadbeef") + atexit.register(exit_handler) + + def test_atexit(self): + # gh-83856 + with os_helper.temp_dir() as temp_dir: + output_path = os.path.join(temp_dir, 'output.txt') + p = self.Process(target=self._write_file_at_exit, args=(output_path,)) + p.start() + p.join() + with open(output_path) as f: + self.assertEqual(f.read(), 'deadbeef') + + class MiscTestCase(unittest.TestCase): def test__all__(self): # Just make sure names in not_exported are excluded diff --git a/Misc/NEWS.d/next/Library/2024-01-19-05-40-46.gh-issue-83856.jN5M80.rst b/Misc/NEWS.d/next/Library/2024-01-19-05-40-46.gh-issue-83856.jN5M80.rst new file mode 100644 index 0000000..b2889f2 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-01-19-05-40-46.gh-issue-83856.jN5M80.rst @@ -0,0 +1 @@ +Honor :mod:`atexit` for all :mod:`multiprocessing` start methods -- cgit v0.12