From 1d276ec6f8403590a6a1a18c560ce75b9221572b Mon Sep 17 00:00:00 2001
From: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Date: Mon, 16 Dec 2024 20:18:02 +0200
Subject: [PATCH] Revert "gh-127586: properly restore blocked signals in
 resource_tracker.py (GH-127587)" (#127983)

This reverts commit 46006a1b355f75d06c10e7b8086912c483b34487.
---
 Lib/multiprocessing/resource_tracker.py           |  7 +++----
 Lib/test/_test_multiprocessing.py                 | 15 ---------------
 ...2024-12-03-20-28-08.gh-issue-127586.zgotYF.rst |  3 ---
 3 files changed, 3 insertions(+), 22 deletions(-)
 delete mode 100644 Misc/NEWS.d/next/Library/2024-12-03-20-28-08.gh-issue-127586.zgotYF.rst

diff --git a/Lib/multiprocessing/resource_tracker.py b/Lib/multiprocessing/resource_tracker.py
index 90e036ae905afa..20ddd9c50e3d88 100644
--- a/Lib/multiprocessing/resource_tracker.py
+++ b/Lib/multiprocessing/resource_tracker.py
@@ -155,14 +155,13 @@ def ensure_running(self):
                 # that can make the child die before it registers signal handlers
                 # for SIGINT and SIGTERM. The mask is unregistered after spawning
                 # the child.
-                prev_sigmask = None
                 try:
                     if _HAVE_SIGMASK:
-                        prev_sigmask = signal.pthread_sigmask(signal.SIG_BLOCK, _IGNORED_SIGNALS)
+                        signal.pthread_sigmask(signal.SIG_BLOCK, _IGNORED_SIGNALS)
                     pid = util.spawnv_passfds(exe, args, fds_to_pass)
                 finally:
-                    if prev_sigmask is not None:
-                        signal.pthread_sigmask(signal.SIG_SETMASK, prev_sigmask)
+                    if _HAVE_SIGMASK:
+                        signal.pthread_sigmask(signal.SIG_UNBLOCK, _IGNORED_SIGNALS)
             except:
                 os.close(w)
                 raise
diff --git a/Lib/test/_test_multiprocessing.py b/Lib/test/_test_multiprocessing.py
index 01e92f0d8d6b30..80b08b8ac66899 100644
--- a/Lib/test/_test_multiprocessing.py
+++ b/Lib/test/_test_multiprocessing.py
@@ -6044,21 +6044,6 @@ def test_resource_tracker_exit_code(self):
                 self._test_resource_tracker_leak_resources(
                     cleanup=cleanup,
                 )
-    @unittest.skipUnless(hasattr(signal, "pthread_sigmask"), "pthread_sigmask is not available")
-    def test_resource_tracker_blocked_signals(self):
-        #
-        # gh-127586: Check that resource_tracker does not override blocked signals of caller.
-        #
-        from multiprocessing.resource_tracker import ResourceTracker
-        signals = {signal.SIGTERM, signal.SIGINT, signal.SIGUSR1}
-
-        for sig in signals:
-            signal.pthread_sigmask(signal.SIG_SETMASK, {sig})
-            self.assertEqual(signal.pthread_sigmask(signal.SIG_BLOCK, set()), {sig})
-            tracker = ResourceTracker()
-            tracker.ensure_running()
-            self.assertEqual(signal.pthread_sigmask(signal.SIG_BLOCK, set()), {sig})
-            tracker._stop()
 
 class TestSimpleQueue(unittest.TestCase):
 
diff --git a/Misc/NEWS.d/next/Library/2024-12-03-20-28-08.gh-issue-127586.zgotYF.rst b/Misc/NEWS.d/next/Library/2024-12-03-20-28-08.gh-issue-127586.zgotYF.rst
deleted file mode 100644
index 80217bd4a10503..00000000000000
--- a/Misc/NEWS.d/next/Library/2024-12-03-20-28-08.gh-issue-127586.zgotYF.rst
+++ /dev/null
@@ -1,3 +0,0 @@
-:class:`multiprocessing.pool.Pool` now properly restores blocked signal handlers
-of the parent thread when creating processes via either *spawn* or
-*forkserver*.