From 5804f878e779712e803be927ca8a6df389d82cdf Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Tue, 24 Mar 2020 16:32:26 +0100 Subject: bpo-20526: Fix PyThreadState_Clear(): don't decref frame (GH-19120) PyThreadState.frame is a borrowed reference, not a strong reference: PyThreadState_Clear() must not call Py_CLEAR(tstate->frame). Remove test_threading.test_warnings_at_exit(): we cannot warranty that the Python thread state of daemon threads is cleared in a reliable way during Python shutdown. --- Python/pystate.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'Python/pystate.c') diff --git a/Python/pystate.c b/Python/pystate.c index 6331a854c8..8f0b6b87d6 100644 --- a/Python/pystate.c +++ b/Python/pystate.c @@ -765,11 +765,19 @@ PyThreadState_Clear(PyThreadState *tstate) { int verbose = tstate->interp->config.verbose; - if (verbose && tstate->frame != NULL) + if (verbose && tstate->frame != NULL) { + /* bpo-20526: After the main thread calls + _PyRuntimeState_SetFinalizing() in Py_FinalizeEx(), threads must + exit when trying to take the GIL. If a thread exit in the middle of + _PyEval_EvalFrameDefault(), tstate->frame is not reset to its + previous value. It is more likely with daemon threads, but it can + happen with regular threads if threading._shutdown() fails + (ex: interrupted by CTRL+C). */ fprintf(stderr, "PyThreadState_Clear: warning: thread still has a frame\n"); + } - Py_CLEAR(tstate->frame); + /* Don't clear tstate->frame: it is a borrowed reference */ Py_CLEAR(tstate->dict); Py_CLEAR(tstate->async_exc); -- cgit v1.2.1