From e623dedab28a1fec6270c05f9643e68bfb98b7c3 Mon Sep 17 00:00:00 2001 From: Garrett D'Amore Date: Sat, 25 Nov 2023 17:35:35 -0800 Subject: fixes #1523 rare SEGV in sub nni_list_remove Credit goes to Wu Xuan (@willwu1217) for diagnosing and proposing a fix as part of #1695. This approach takes a revised approach to avoid adding extra memory, and it also is slightly faster as we do not need to update both pointers in the linked list, by reusing the reap node. As part of this a new internal API, nni_aio_completions, is introduced. In all likelihood we will be able to use this to solve some similar crashes in other areas of the code. --- src/core/aio.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'src/core/aio.c') diff --git a/src/core/aio.c b/src/core/aio.c index 564e91a3..e849b33d 100644 --- a/src/core/aio.c +++ b/src/core/aio.c @@ -508,6 +508,39 @@ nni_aio_list_active(nni_aio *aio) return (nni_list_node_active(&aio->a_prov_node)); } +// completions list. +// Implementation note: in order to avoid wasting space, we +// reuse the reap node -- which will be inactive here. +void +nni_aio_completions_init(nni_aio_completions *clp) +{ + *clp = NULL; +} + +void +nni_aio_completions_add(nni_aio_completions *clp, nni_aio *aio, int result, size_t count) +{ + NNI_ASSERT(!nni_aio_list_active(aio)); + aio->a_reap_node.rn_next = *clp; + aio->a_result = result; + aio->a_count = count; + *clp = aio; +} + +void +nni_aio_completions_run(nni_aio_completions *clp) +{ + nni_aio *aio; + nni_aio *cl = *clp; + *clp = NULL; + + while ((aio = cl) != NULL) { + cl = (void *)aio->a_reap_node.rn_next; + aio->a_reap_node.rn_next = NULL; + nni_aio_finish_sync(aio, aio->a_result, aio->a_count); + } +} + static void nni_aio_expire_add(nni_aio *aio) { -- cgit v1.2.3-70-g09d2