From 665bb1ddb761e50a5c2762ea877a497109c91280 Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@python.org>
Date: Mon, 15 Jun 2026 18:19:59 +0200
Subject: [PATCH 1/3] gh-151496: Use process groups in test_dtrace

Create a new process group to run bpftrace commands, so it's possible
to kill also child processes on timeout.
---
 Lib/test/test_dtrace.py | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/Lib/test/test_dtrace.py b/Lib/test/test_dtrace.py
index 6286b6d21b572e3..5b977c347edaf45 100644
--- a/Lib/test/test_dtrace.py
+++ b/Lib/test/test_dtrace.py
@@ -1,6 +1,7 @@
 import dis
 import os.path
 import re
+import signal
 import subprocess
 import sys
 import sysconfig
@@ -50,6 +51,26 @@ def normalize_trace_output(output):
         )
 
 
+USE_PROCESS_GROUP = (hasattr(os, "setsid") and hasattr(os, "killpg"))
+
+def create_process_group(*args, **kwargs):
+    if USE_PROCESS_GROUP:
+        kwargs['start_new_session'] = True
+    return subprocess.Popen(*args, **kwargs)
+
+def kill_process_group(proc):
+    use_killpg = USE_PROCESS_GROUP
+    if use_killpg:
+        parent_sid = os.getsid(0)
+        sid = os.getsid(proc.pid)
+        use_killpg = (sid != parent_sid)
+
+    if use_killpg:
+        os.killpg(proc.pid, signal.SIGKILL)
+    else:
+        proc.kill()
+
+
 class TraceBackend:
     EXTENSION = None
     COMMAND = None
@@ -205,7 +226,7 @@ def run_case(self, name, optimize_python=None):
         program = self.PROGRAMS[name].format(python=sys.executable)
 
         try:
-            proc = subprocess.Popen(
+            proc = create_process_group(
                 ["bpftrace", "-e", program, "-c", " ".join(subcommand)],
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE,
@@ -213,7 +234,7 @@ def run_case(self, name, optimize_python=None):
             )
             stdout, stderr = proc.communicate(timeout=60)
         except subprocess.TimeoutExpired:
-            proc.kill()
+            kill_process_group(proc)
             raise AssertionError("bpftrace timed out")
         except (FileNotFoundError, PermissionError) as e:
             raise unittest.SkipTest(f"bpftrace not available: {e}")
@@ -243,7 +264,7 @@ def assert_usable(self):
         # Check if bpftrace is available and can attach to USDT probes
         program = f'usdt:{sys.executable}:python:function__entry {{ printf("probe: success\\n"); exit(); }}'
         try:
-            proc = subprocess.Popen(
+            proc = create_process_group(
                 ["bpftrace", "-e", program, "-c", f"{sys.executable} -c pass"],
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE,
@@ -251,7 +272,7 @@ def assert_usable(self):
             )
             stdout, stderr = proc.communicate(timeout=10)
         except subprocess.TimeoutExpired:
-            proc.kill()
+            kill_process_group(proc)
             proc.communicate()  # Clean up
             raise unittest.SkipTest("bpftrace timed out during usability check")
         except OSError as e:

From 81ebe07c8273b2853fcb04cc78b48aca1c027b54 Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@python.org>
Date: Mon, 15 Jun 2026 18:26:01 +0200
Subject: [PATCH 2/3] Simplify kill_process_group()

---
 Lib/test/test_dtrace.py | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/Lib/test/test_dtrace.py b/Lib/test/test_dtrace.py
index 5b977c347edaf45..5ade826756b7c9c 100644
--- a/Lib/test/test_dtrace.py
+++ b/Lib/test/test_dtrace.py
@@ -59,13 +59,7 @@ def create_process_group(*args, **kwargs):
     return subprocess.Popen(*args, **kwargs)
 
 def kill_process_group(proc):
-    use_killpg = USE_PROCESS_GROUP
-    if use_killpg:
-        parent_sid = os.getsid(0)
-        sid = os.getsid(proc.pid)
-        use_killpg = (sid != parent_sid)
-
-    if use_killpg:
+    if USE_PROCESS_GROUP:
         os.killpg(proc.pid, signal.SIGKILL)
     else:
         proc.kill()

From b5bf28700ca1d710e25da538567030cf3e055594 Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@python.org>
Date: Tue, 16 Jun 2026 12:15:30 +0200
Subject: [PATCH 3/3] Address stratakis' review

---
 Lib/test/test_dtrace.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/Lib/test/test_dtrace.py b/Lib/test/test_dtrace.py
index 5ade826756b7c9c..592f59d77f92217 100644
--- a/Lib/test/test_dtrace.py
+++ b/Lib/test/test_dtrace.py
@@ -60,9 +60,13 @@ def create_process_group(*args, **kwargs):
 
 def kill_process_group(proc):
     if USE_PROCESS_GROUP:
-        os.killpg(proc.pid, signal.SIGKILL)
+        try:
+            os.killpg(proc.pid, signal.SIGKILL)
+        except ProcessLookupError:
+            pass
     else:
         proc.kill()
+    proc.communicate()  # Clean up
 
 
 class TraceBackend:
@@ -267,7 +271,6 @@ def assert_usable(self):
             stdout, stderr = proc.communicate(timeout=10)
         except subprocess.TimeoutExpired:
             kill_process_group(proc)
-            proc.communicate()  # Clean up
             raise unittest.SkipTest("bpftrace timed out during usability check")
         except OSError as e:
             raise unittest.SkipTest(f"bpftrace not available: {e}")