gh-140373: Correctly emit PY_UNWIND event when generator is closed (GH-140767)

Author: efimov-mikhail

Include/internal/pycore_ceval.h

@@ -301,6 +301,7 @@ PyAPI_FUNC(PyObject *) _PyEval_ImportName(PyThreadState *, _PyInterpreterFrame *
 PyAPI_FUNC(PyObject *)_PyEval_MatchClass(PyThreadState *tstate, PyObject *subject, PyObject *type, Py_ssize_t nargs, PyObject *kwargs);
 PyAPI_FUNC(PyObject *)_PyEval_MatchKeys(PyThreadState *tstate, PyObject *map, PyObject *keys);
 PyAPI_FUNC(void) _PyEval_MonitorRaise(PyThreadState *tstate, _PyInterpreterFrame *frame, _Py_CODEUNIT *instr);
+PyAPI_FUNC(bool) _PyEval_NoToolsForUnwind(PyThreadState *tstate);
 PyAPI_FUNC(int) _PyEval_UnpackIterableStackRef(PyThreadState *tstate, PyObject *v, int argcnt, int argcntafter, _PyStackRef *sp);
 PyAPI_FUNC(void) _PyEval_FrameClearAndPop(PyThreadState *tstate, _PyInterpreterFrame *frame);
 PyAPI_FUNC(PyObject **) _PyObjectArray_FromStackRefArray(_PyStackRef *input, Py_ssize_t nargs, PyObject **scratch);

Lib/test/test_monitoring.py

@@ -1079,6 +1079,25 @@ def f():
 
         self.assertEqual(events, expected)
 
+    # gh-140373
+    def test_gen_unwind(self):
+        def gen():
+            yield 1
+
+        def f():
+            g = gen()
+            next(g)
+            g.close()
+
+        recorders = (
+            UnwindRecorder,
+        )
+        events = self.get_events(f, TEST_TOOL, recorders)
+        expected = [
+            ("unwind", GeneratorExit, "gen"),
+        ]
+        self.assertEqual(events, expected)
+
 class LineRecorder:
 
     event_type = E.LINE

Lib/test/test_sys_setprofile.py

@@ -272,6 +272,8 @@ def g(p):
         self.check_events(g, [(1, 'call', g_ident, None),
                               (2, 'call', f_ident, None),
                               (2, 'return', f_ident, 0),
+                              (2, 'call', f_ident, None),
+                              (2, 'return', f_ident, None),
                               (1, 'return', g_ident, None),
                               ], check_args=True)
 

Misc/NEWS.d/next/Core_and_Builtins/2025-10-29-20-59-10.gh-issue-140373.-uoaPP.rst

@@ -0,0 +1,2 @@
+Correctly emit ``PY_UNWIND`` event when generator object is closed. Patch by
+Mikhail Efimov.

Objects/genobject.c

@@ -407,11 +407,12 @@ gen_close(PyObject *self, PyObject *args)
     }
     _PyInterpreterFrame *frame = &gen->gi_iframe;
     if (is_resume(frame->instr_ptr)) {
+        bool no_unwind_tools = _PyEval_NoToolsForUnwind(_PyThreadState_GET());
         /* We can safely ignore the outermost try block
          * as it is automatically generated to handle
          * StopIteration. */
         int oparg = frame->instr_ptr->op.arg;
-        if (oparg & RESUME_OPARG_DEPTH1_MASK) {
+        if (oparg & RESUME_OPARG_DEPTH1_MASK && no_unwind_tools) {
             // RESUME after YIELD_VALUE and exception depth is 1
             assert((oparg & RESUME_OPARG_LOCATION_MASK) != RESUME_AT_FUNC_START);
             gen->gi_frame_state = FRAME_COMPLETED;

Python/ceval.c

@@ -2466,6 +2466,10 @@ monitor_unwind(PyThreadState *tstate,
     do_monitor_exc(tstate, frame, instr, PY_MONITORING_EVENT_PY_UNWIND);
 }
 
+bool
+_PyEval_NoToolsForUnwind(PyThreadState *tstate) {
+    return no_tools_for_global_event(tstate, PY_MONITORING_EVENT_PY_UNWIND);
+}
 
 static int
 monitor_handled(PyThreadState *tstate,