From d9b8d1329c19dbbd60a36d0e5e7efee06047531e Mon Sep 17 00:00:00 2001
From: yonatan-genai <yonatanh@gmail.com>
Date: Fri, 3 Apr 2026 23:58:46 +0300
Subject: [PATCH 1/2] gh-144766: Fix flaky test_trampoline_works_with_forks

The fork child ran full Python finalization instead of calling
os._exit(0), which is fragile when perf trampoline support is active
(unmapping executable memory and unregistering code watchers during
finalization can crash intermittently). The newer test added in the
same file (test_trampoline_works_after_fork_with_many_code_objects)
already uses os._exit(0) for this reason.

Also fix the parent's wait status handling: os.waitpid returns a raw
wait status, not an exit code. Use os.WEXITSTATUS to extract the
actual exit code, and check os.WIFSIGNALED for signal deaths.

<claude>
---
 Lib/test/test_perf_profiler.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_perf_profiler.py b/Lib/test/test_perf_profiler.py
index 597e6599352049..91a83531d0fb75 100644
--- a/Lib/test/test_perf_profiler.py
+++ b/Lib/test/test_perf_profiler.py
@@ -118,9 +118,12 @@ def foo():
                     if pid == 0:
                         print(os.getpid())
                         baz_fork()
+                        os._exit(0)
                     else:
                         _, status = os.waitpid(-1, 0)
-                        sys.exit(status)
+                        if os.WIFSIGNALED(status):
+                            sys.exit(1)
+                        sys.exit(os.WEXITSTATUS(status))
 
                 def bar():
                     foo()

From d9fa578036f3cbc0bca7e089b94a07a890b925f7 Mon Sep 17 00:00:00 2001
From: yonatan-genai <yonatanh@gmail.com>
Date: Sat, 4 Apr 2026 00:31:04 +0300
Subject: [PATCH 2/2] Add flush=True before os._exit and add NEWS entry

os._exit() does not flush Python IO buffers, so the print(os.getpid())
output was lost when stdout is piped. Add flush=True to ensure the
child PID reaches the parent.

Also add the required NEWS entry.

<claude>
---
 Lib/test/test_perf_profiler.py                                | 2 +-
 .../next/Tests/2026-04-04-00-00-00.gh-issue-144766.Yk3mPq.rst | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)
 create mode 100644 Misc/NEWS.d/next/Tests/2026-04-04-00-00-00.gh-issue-144766.Yk3mPq.rst

diff --git a/Lib/test/test_perf_profiler.py b/Lib/test/test_perf_profiler.py
index 91a83531d0fb75..ae6bfe513eba81 100644
--- a/Lib/test/test_perf_profiler.py
+++ b/Lib/test/test_perf_profiler.py
@@ -116,7 +116,7 @@ def baz_fork():
                 def foo():
                     pid = os.fork()
                     if pid == 0:
-                        print(os.getpid())
+                        print(os.getpid(), flush=True)
                         baz_fork()
                         os._exit(0)
                     else:
diff --git a/Misc/NEWS.d/next/Tests/2026-04-04-00-00-00.gh-issue-144766.Yk3mPq.rst b/Misc/NEWS.d/next/Tests/2026-04-04-00-00-00.gh-issue-144766.Yk3mPq.rst
new file mode 100644
index 00000000000000..6851b470e1ac97
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2026-04-04-00-00-00.gh-issue-144766.Yk3mPq.rst
@@ -0,0 +1,4 @@
+Fix flaky :func:`test_trampoline_works_with_forks` by using ``os._exit(0)``
+in the fork child to avoid fragile Python finalization, and by flushing
+stdout before exit. Also fix the parent's wait status handling to use
+``os.WEXITSTATUS()``.