Date: Tue, 6 May 2025 17:15:05 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: e8286eb29516 - main - sys/queue.h: add STAILQ_REVERSE Message-ID: <202505061715.546HF5QT089292@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=e8286eb295165ea1852abe4ae355f85ad1ec3356 commit e8286eb295165ea1852abe4ae355f85ad1ec3356 Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2025-05-03 08:13:14 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2025-05-06 17:14:56 +0000 sys/queue.h: add STAILQ_REVERSE The implementation of the traditional interview question about in-place reversing of the single-linked list. Reviewed by: markj, olce Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D50131 --- sys/sys/queue.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/sys/sys/queue.h b/sys/sys/queue.h index a29ad6b94f03..b2ba3d63bb0c 100644 --- a/sys/sys/queue.h +++ b/sys/sys/queue.h @@ -564,6 +564,21 @@ struct { \ (head2)->stqh_last = &STAILQ_FIRST(head2); \ } while (0) +#define STAILQ_REVERSE(head, type, field) do { \ + if (STAILQ_EMPTY(head)) \ + break; \ + QUEUE_TYPEOF(type) *_Var, *_Varp, *_Varn; \ + for (_Var = STAILQ_FIRST(head), _Varp = NULL; \ + _Var != NULL;) { \ + _Varn = STAILQ_NEXT(_Var, field); \ + STAILQ_NEXT(_Var, field) = _Varp; \ + _Varp = _Var; \ + _Var = _Varn; \ + } \ + (head)->stqh_last = &STAILQ_NEXT(STAILQ_FIRST(head), field); \ + (head)->stqh_first = _Varp; \ +} while (0) + #define STAILQ_END(head) NULL
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202505061715.546HF5QT089292>