[3.15] gh-154431: Revert "gh-154431: Fix data race in sys.audithook (GH-154462)" (GH-154769) (GH-154774)

This reverts commit 596cd5c.
This commit caused a refleak.

(cherry picked from commit c7b9a13)

Co-authored-by: Petr Viktorin <encukou@gmail.com>

Author: miss-islington

Include/internal/pycore_interp_structs.h

@@ -988,7 +988,6 @@ struct _is {
     struct _obmalloc_state *obmalloc;
 
     PyObject *audit_hooks;
-    PyMutex audit_hooks_mutex;
     PyType_WatchCallback type_watchers[TYPE_MAX_WATCHERS];
     PyCode_WatchCallback code_watchers[CODE_MAX_WATCHERS];
     PyContext_WatchCallback context_watchers[CONTEXT_MAX_WATCHERS];

Lib/test/test_free_threading/test_sys.py

@@ -44,20 +44,6 @@ def worker(worker_id):
         workers = [lambda: worker(i) for i in range(5)]
         threading_helper.run_concurrently(workers)
 
-    def test_sys_audit_hooks(self):
-        def _hook(*args):
-            return None
-
-        def adder():
-            for _ in range(100):
-                sys.addaudithook(_hook)
-
-        def auditor():
-            for _ in range(2000):
-                sys.audit("fusil.tsan.test")
-
-        threading_helper.run_concurrently([adder, auditor])
-
 
 if __name__ == "__main__":
     unittest.main()

Misc/NEWS.d/next/Library/2026-07-22-12-42-53.gh-issue-154431.U2kXXZ.rst

@@ -580,7 +580,6 @@ init_interpreter(PyInterpreterState *interp,
     llist_init(&interp->mem_free_queue.head);
     llist_init(&interp->asyncio_tasks_head);
     interp->asyncio_tasks_lock = (PyMutex){0};
-    interp->audit_hooks_mutex = (PyMutex){0};
     for (int i = 0; i < _PY_MONITORING_UNGROUPED_EVENTS; i++) {
         interp->monitors.tools[i] = 0;
     }

Python/pystate.c

@@ -236,7 +236,7 @@ should_audit(PyInterpreterState *interp)
         return 0;
     }
     return (interp->runtime->audit_hooks.head
-            || FT_ATOMIC_LOAD_PTR_ACQUIRE(interp->audit_hooks)
+            || interp->audit_hooks
             || PyDTrace_AUDIT_ENABLED());
 }
 
@@ -306,14 +306,13 @@ sys_audit_tstate(PyThreadState *ts, const char *event,
     }
 
     /* Call interpreter hooks */
-    PyObject *audit_hooks = FT_ATOMIC_LOAD_PTR_ACQUIRE(is->audit_hooks);
-    if (audit_hooks) {
+    if (is->audit_hooks) {
         eventName = PyUnicode_FromString(event);
         if (!eventName) {
             goto exit;
         }
 
-        hooks = PyObject_GetIter(audit_hooks);
+        hooks = PyObject_GetIter(is->audit_hooks);
         if (!hooks) {
             goto exit;
         }
@@ -537,29 +536,20 @@ sys_addaudithook_impl(PyObject *module, PyObject *hook)
     }
 
     PyInterpreterState *interp = tstate->interp;
-    PyMutex mutex = interp->audit_hooks_mutex;
-    PyMutex_Lock(&mutex);
-
     if (interp->audit_hooks == NULL) {
-        PyObject *new_list = PyList_New(0);
-        if (new_list == NULL) {
-            goto error;
+        interp->audit_hooks = PyList_New(0);
+        if (interp->audit_hooks == NULL) {
+            return NULL;
         }
         /* Avoid having our list of hooks show up in the GC module */
-        PyObject_GC_UnTrack(new_list);
-        FT_ATOMIC_STORE_PTR_RELEASE(interp->audit_hooks, new_list);
+        PyObject_GC_UnTrack(interp->audit_hooks);
     }
 
     if (PyList_Append(interp->audit_hooks, hook) < 0) {
-        goto error;
+        return NULL;
     }
 
-    PyMutex_Unlock(&mutex);
     Py_RETURN_NONE;
-
-error:
-    PyMutex_Unlock(&mutex);
-    return NULL;
 }
 
 /*[clinic input]