Merge branch 'main' into small_int_immortal

Author: eendebakpt

Doc/library/argparse.rst

@@ -195,7 +195,7 @@ your usage messages.
 When a custom usage message is specified for the main parser, you may also want to
 consider passing  the ``prog`` argument to :meth:`~ArgumentParser.add_subparsers`
 or the ``prog`` and the ``usage`` arguments to
-:meth:`~_SubParsersAction.add_parser`, to ensure consistent command prefixes and 
+:meth:`~_SubParsersAction.add_parser`, to ensure consistent command prefixes and
 usage information across subparsers.
 
 

Include/internal/pycore_interp.h

@@ -283,6 +283,8 @@ struct _is {
 
     /* the initial PyInterpreterState.threads.head */
     _PyThreadStateImpl _initial_thread;
+    // _initial_thread should be the last field of PyInterpreterState.
+    // See https://github.com/python/cpython/issues/127117.
 };
 
 

Include/internal/pycore_runtime.h

@@ -169,6 +169,12 @@ typedef struct pyruntimestate {
     struct _Py_unicode_runtime_state unicode_state;
     struct _types_runtime_state types;
 
+#if defined(__EMSCRIPTEN__) && defined(PY_CALL_TRAMPOLINE)
+    // Used in "Python/emscripten_trampoline.c" to choose between type
+    // reflection trampoline and EM_JS trampoline.
+    bool wasm_type_reflection_available;
+#endif
+
     /* All the objects that are shared by the runtime's interpreters. */
     struct _Py_cached_objects cached_objects;
     struct _Py_static_objects static_objects;
@@ -189,13 +195,8 @@ typedef struct pyruntimestate {
 
     /* _PyRuntimeState.interpreters.main */
     PyInterpreterState _main_interpreter;
-
-#if defined(__EMSCRIPTEN__) && defined(PY_CALL_TRAMPOLINE)
-    // Used in "Python/emscripten_trampoline.c" to choose between type
-    // reflection trampoline and EM_JS trampoline.
-    bool wasm_type_reflection_available;
-#endif
-
+    // _main_interpreter should be the last field of _PyRuntimeState.
+    // See https://github.com/python/cpython/issues/127117.
 } _PyRuntimeState;
 
 

Lib/concurrent/futures/thread.py

@@ -41,6 +41,7 @@ def _python_exit():
     os.register_at_fork(before=_global_shutdown_lock.acquire,
                         after_in_child=_global_shutdown_lock._at_fork_reinit,
                         after_in_parent=_global_shutdown_lock.release)
+    os.register_at_fork(after_in_child=_threads_queues.clear)
 
 
 class WorkerContext:

Lib/test/test_concurrent_futures/test_thread_pool.py

@@ -66,6 +66,25 @@ def submit(pool):
                 with futures.ProcessPoolExecutor(1, mp_context=mp.get_context('fork')) as workers:
                     workers.submit(tuple)
 
+    @support.requires_fork()
+    @unittest.skipUnless(hasattr(os, 'register_at_fork'), 'need os.register_at_fork')
+    def test_process_fork_from_a_threadpool(self):
+        # bpo-43944: clear concurrent.futures.thread._threads_queues after fork,
+        # otherwise child process will try to join parent thread
+        def fork_process_and_return_exitcode():
+            # Ignore the warning about fork with threads.
+            with self.assertWarnsRegex(DeprecationWarning,
+                                       r"use of fork\(\) may lead to deadlocks in the child"):
+                p = mp.get_context('fork').Process(target=lambda: 1)
+                p.start()
+            p.join()
+            return p.exitcode
+
+        with futures.ThreadPoolExecutor(1) as pool:
+            process_exitcode = pool.submit(fork_process_and_return_exitcode).result()
+
+        self.assertEqual(process_exitcode, 0)
+
     def test_executor_map_current_future_cancel(self):
         stop_event = threading.Event()
         log = []

Misc/NEWS.d/next/Library/2023-02-15-23-54-42.gh-issue-88110.KU6erv.rst

@@ -0,0 +1,2 @@
+Fixed :class:`multiprocessing.Process` reporting a ``.exitcode`` of 1 even on success when
+using the ``"fork"`` start method while using a :class:`concurrent.futures.ThreadPoolExecutor`.