Apr 24, 2025 · Apr 24, 2025 · Apr 25, 2025 · Apr 25, 2025 · Apr 25, 2025 · Apr 25, 2025
diff --git a/Include/cpython/pystate.h b/Include/cpython/pystate.h
 * PyThreadState_Ensure() or PyInterpreterState_Release(). */
 PyAPI_FUNC(PyInterpreterState *) PyInterpreterState_Hold(void);

 PyAPI_FUNC(PyInterpreterState *) PyInterpreterState_Lookup(int64_t interp_id);

 /* Release a reference to an interpreter incremented by PyInterpreterState_Hold() */
 PyAPI_FUNC(void) PyInterpreterState_Release(PyInterpreterState *interp);

diff --git a/Python/pystate.c b/Python/pystate.c
 int
 _PyThreadState_MustExit(PyThreadState *tstate)
 {
    if (!tstate->daemon) {
        return 0;
    }
    int state = _Py_atomic_load_int_relaxed(&tstate->state);
    return state == _Py_THREAD_SHUTTING_DOWN;
 }
    return interp;
 }

 PyInterpreterState *
 PyInterpreterState_Lookup(int64_t interp_id)
 {
    PyInterpreterState *interp = _PyInterpreterState_LookUpID(interp_id);
    if (interp == NULL) {
        return NULL;
    }
    HEAD_LOCK(&_PyRuntime); // Prevent deletion
    struct _Py_finalizing_threads finalizing = interp->threads.finalizing;
    PyMutex *mutex = &finalizing.mutex;
    PyMutex_Lock(mutex); // Synchronize TOCTOU with the event flag
    if (_PyEvent_IsSet(&finalizing.finished)) {
        /* Interpreter has already finished threads */
        interp = NULL;
    } else {
        _Py_atomic_add_ssize(&finalizing.countdown, 1);
    }
    PyMutex_Unlock(mutex);
    HEAD_UNLOCK(&_PyRuntime);

    return interp;
 }

 void
 PyInterpreterState_Release(PyInterpreterState *interp)
 {
Original file line number	Diff line number	Diff line change
Expand Up		@@ -283,6 +283,8 @@ PyAPI_FUNC(void) _PyInterpreterState_SetEvalFrameFunc(
		* PyThreadState_Ensure() or PyInterpreterState_Release(). */
		PyAPI_FUNC(PyInterpreterState *) PyInterpreterState_Hold(void);

		PyAPI_FUNC(PyInterpreterState *) PyInterpreterState_Lookup(int64_t interp_id);

		/* Release a reference to an interpreter incremented by PyInterpreterState_Hold() */
		PyAPI_FUNC(void) PyInterpreterState_Release(PyInterpreterState *interp);

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Original file line number	Diff line number	Diff line change
Expand Up		@@ -3074,9 +3074,6 @@ _PyThreadState_CheckConsistency(PyThreadState *tstate)
		int
		_PyThreadState_MustExit(PyThreadState *tstate)
		{
		if (!tstate->daemon) {
		return 0;
		}
		int state = _Py_atomic_load_int_relaxed(&tstate->state);
		return state == _Py_THREAD_SHUTTING_DOWN;
		}
Expand DownExpand Up		@@ -3221,6 +3218,29 @@ PyInterpreterState_Hold(void)
		return interp;
		}

		PyInterpreterState *
		PyInterpreterState_Lookup(int64_t interp_id)
		{
		PyInterpreterState *interp = _PyInterpreterState_LookUpID(interp_id);
		if (interp == NULL) {
		return NULL;
		}
		HEAD_LOCK(&_PyRuntime); // Prevent deletion
		struct _Py_finalizing_threads finalizing = interp->threads.finalizing;
		PyMutex *mutex = &finalizing.mutex;
		PyMutex_Lock(mutex); // Synchronize TOCTOU with the event flag
		if (_PyEvent_IsSet(&finalizing.finished)) {
		/* Interpreter has already finished threads */
		interp = NULL;
		} else {
		_Py_atomic_add_ssize(&finalizing.countdown, 1);
		}
		PyMutex_Unlock(mutex);
		HEAD_UNLOCK(&_PyRuntime);

		return interp;
		}

		void
		PyInterpreterState_Release(PyInterpreterState *interp)
		{
Expand Down