diff options
| -rw-r--r-- | Include/cpython/pystate.h | 1 | ||||
| -rw-r--r-- | Lib/test/test_threading.py | 28 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Core and Builtins/2020-03-23-18-08-34.bpo-20526.NHNZIv.rst | 3 | ||||
| -rw-r--r-- | Python/pystate.c | 12 |
4 files changed, 14 insertions, 30 deletions
diff --git a/Include/cpython/pystate.h b/Include/cpython/pystate.h index de35296..4ea509d 100644 --- a/Include/cpython/pystate.h +++ b/Include/cpython/pystate.h @@ -55,6 +55,7 @@ struct _ts { struct _ts *next; PyInterpreterState *interp; + /* Borrowed reference to the current frame (it can be NULL) */ struct _frame *frame; int recursion_depth; char overflowed; /* The stack has overflowed. Allow 50 more calls diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py index 87c68df..f1037b5 100644 --- a/Lib/test/test_threading.py +++ b/Lib/test/test_threading.py @@ -776,34 +776,6 @@ class ThreadTests(BaseTestCase): """) self.assertEqual(out.rstrip(), b"thread_dict.atexit = 'value'") - def test_warnings_at_exit(self): - # bpo-19466: try to call most destructors at Python shutdown before - # destroying Python thread states - filename = __file__ - rc, out, err = assert_python_ok("-Wd", "-c", """if 1: - import time - import threading - from test import support - - def open_sleep(): - # a warning will be emitted when the open file will be - # destroyed (without being explicitly closed) while the daemon - # thread is destroyed - fileobj = open(%a, 'rb') - start_event.set() - time.sleep(support.LONG_TIMEOUT) - - start_event = threading.Event() - - thread = threading.Thread(target=open_sleep, daemon=True) - thread.start() - - # wait until the thread started - start_event.wait() - """ % filename) - self.assertRegex(err.rstrip(), - b"^sys:1: ResourceWarning: unclosed file ") - class ThreadJoinOnShutdown(BaseTestCase): diff --git a/Misc/NEWS.d/next/Core and Builtins/2020-03-23-18-08-34.bpo-20526.NHNZIv.rst b/Misc/NEWS.d/next/Core and Builtins/2020-03-23-18-08-34.bpo-20526.NHNZIv.rst new file mode 100644 index 0000000..c808b76 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2020-03-23-18-08-34.bpo-20526.NHNZIv.rst @@ -0,0 +1,3 @@ +Fix :c:func:`PyThreadState_Clear()`. ``PyThreadState.frame`` is a borrowed +reference, not a strong reference: ``PyThreadState_Clear()`` must not call +``Py_CLEAR(tstate->frame)``. diff --git a/Python/pystate.c b/Python/pystate.c index 6331a85..8f0b6b8 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); |