diff --git a/Lib/test/test_memoryio.py b/Lib/test/test_memoryio.py index 731299294e6877..8192502a40791b 100644 --- a/Lib/test/test_memoryio.py +++ b/Lib/test/test_memoryio.py @@ -6,10 +6,12 @@ import unittest from test import support +import gc import io import _pyio as pyio import pickle import sys +import weakref class IntLike: def __init__(self, num): @@ -477,6 +479,25 @@ def test_getbuffer_empty(self): buf2.release() memio.write(b'x') + def test_getbuffer_gc_collect(self): + memio = self.ioclass(b"1234567890") + buf = memio.getbuffer() + memiowr = weakref.ref(memio) + bufwr = weakref.ref(buf) + # Create a reference loop. + a = [buf] + a.append(a) + # The Python implementation emits an unraisable exception. + with support.catch_unraisable_exception(): + del memio + del buf + del a + # The C implementation emits an unraisable exception. + with support.catch_unraisable_exception(): + gc.collect() + self.assertIsNone(memiowr()) + self.assertIsNone(bufwr()) + def test_read1(self): buf = self.buftype("1234567890") self.assertEqual(self.ioclass(buf).read1(), buf) diff --git a/Misc/NEWS.d/next/Library/2023-10-23-18-42-26.gh-issue-111049.Ys7-o_.rst b/Misc/NEWS.d/next/Library/2023-10-23-18-42-26.gh-issue-111049.Ys7-o_.rst new file mode 100644 index 00000000000000..b1de348bea0a58 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2023-10-23-18-42-26.gh-issue-111049.Ys7-o_.rst @@ -0,0 +1,2 @@ +Fix crash during garbage collection of the :class:`io.BytesIO` buffer +object. diff --git a/Modules/_io/bytesio.c b/Modules/_io/bytesio.c index 7636394c35a459..9459affa4a87b0 100644 --- a/Modules/_io/bytesio.c +++ b/Modules/_io/bytesio.c @@ -988,7 +988,9 @@ static int bytesio_clear(bytesio *self) { Py_CLEAR(self->dict); - Py_CLEAR(self->buf); + if (self->exports == 0) { + Py_CLEAR(self->buf); + } return 0; } @@ -1093,13 +1095,6 @@ bytesiobuf_releasebuffer(bytesiobuf *obj, Py_buffer *view) b->exports--; } -static int -bytesiobuf_clear(bytesiobuf *self) -{ - Py_CLEAR(self->source); - return 0; -} - static int bytesiobuf_traverse(bytesiobuf *self, visitproc visit, void *arg) { @@ -1114,7 +1109,7 @@ bytesiobuf_dealloc(bytesiobuf *self) PyTypeObject *tp = Py_TYPE(self); /* bpo-31095: UnTrack is needed before calling any callbacks */ PyObject_GC_UnTrack(self); - (void)bytesiobuf_clear(self); + Py_CLEAR(self->source); tp->tp_free(self); Py_DECREF(tp); } @@ -1122,7 +1117,6 @@ bytesiobuf_dealloc(bytesiobuf *self) static PyType_Slot bytesiobuf_slots[] = { {Py_tp_dealloc, bytesiobuf_dealloc}, {Py_tp_traverse, bytesiobuf_traverse}, - {Py_tp_clear, bytesiobuf_clear}, // Buffer protocol {Py_bf_getbuffer, bytesiobuf_getbuffer},