From a23ded48f5f66dc4b232b8f40d61cf26afbc6688 Mon Sep 17 00:00:00 2001
From: sobolevn <mail@sobolevn.me>
Date: Wed, 8 Jul 2026 01:03:47 +0300
Subject: [PATCH 1/2] gh-153292: Fix data race in `threading.RLock.__repr__` in
 FT builds

---
 .../test_free_threading/test_threading.py     | 29 +++++++++++++++++++
 ...-07-08-01-03-17.gh-issue-153292.oHDt3l.rst |  1 +
 Modules/_threadmodule.c                       |  2 +-
 3 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 Lib/test/test_free_threading/test_threading.py
 create mode 100644 Misc/NEWS.d/next/Library/2026-07-08-01-03-17.gh-issue-153292.oHDt3l.rst

diff --git a/Lib/test/test_free_threading/test_threading.py b/Lib/test/test_free_threading/test_threading.py
new file mode 100644
index 00000000000000..ba67f61c37a5dc
--- /dev/null
+++ b/Lib/test/test_free_threading/test_threading.py
@@ -0,0 +1,29 @@
+import unittest
+from test.support import threading_helper
+
+threading_helper.requires_working_threading(module=True)
+
+
+class TestRlock(unittest.TestCase):
+    def test_repr_race(self):
+        # gh-153292
+        import _thread
+        r = _thread.RLock()
+
+        def repr_thread():
+            for _ in range(2000):
+                try:
+                    repr(r)
+                except Exception:
+                    pass
+
+        def mutate_thread():
+            for _ in range(2000):
+                r.acquire()
+                r.release()
+
+        threading_helper.run_concurrently([repr_thread, mutate_thread])
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/Misc/NEWS.d/next/Library/2026-07-08-01-03-17.gh-issue-153292.oHDt3l.rst b/Misc/NEWS.d/next/Library/2026-07-08-01-03-17.gh-issue-153292.oHDt3l.rst
new file mode 100644
index 00000000000000..dc363e16007430
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-07-08-01-03-17.gh-issue-153292.oHDt3l.rst
@@ -0,0 +1 @@
+Fix data race in repr of :class:`threading.RLock` in free-threading build.
diff --git a/Modules/_threadmodule.c b/Modules/_threadmodule.c
index 7e1884edf5213e..e999fe20287e2d 100644
--- a/Modules/_threadmodule.c
+++ b/Modules/_threadmodule.c
@@ -1288,7 +1288,7 @@ static PyObject *
 rlock_repr(PyObject *op)
 {
     rlockobject *self = rlockobject_CAST(op);
-    PyThread_ident_t owner = self->lock.thread;
+    PyThread_ident_t owner = FT_ATOMIC_LOAD_ULLONG_RELAXED(self->lock.thread);
     int locked = rlock_locked_impl(self);
     size_t count;
     if (locked) {

From f36f0d61d3cdd7a259279549556b9706b675da3f Mon Sep 17 00:00:00 2001
From: sobolevn <mail@sobolevn.me>
Date: Wed, 8 Jul 2026 10:36:53 +0300
Subject: [PATCH 2/2] Address review

---
 Lib/test/test_free_threading/test_threading.py | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/Lib/test/test_free_threading/test_threading.py b/Lib/test/test_free_threading/test_threading.py
index ba67f61c37a5dc..b5a5ca272b9405 100644
--- a/Lib/test/test_free_threading/test_threading.py
+++ b/Lib/test/test_free_threading/test_threading.py
@@ -12,10 +12,7 @@ def test_repr_race(self):
 
         def repr_thread():
             for _ in range(2000):
-                try:
-                    repr(r)
-                except Exception:
-                    pass
+                repr(r)
 
         def mutate_thread():
             for _ in range(2000):