1 /* 2 * Copyright (c) 1993 John Brezak 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 19 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 24 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 25 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 #if defined(LIBC_SCCS) && !defined(lint) 31 __RCSID("$NetBSD: insque.c,v 1.2 2005/07/06 17:17:15 drochner Exp $"); 32 #endif /* LIBC_SCCS and not lint */ 33 34 #include <assert.h> 35 #include <search.h> 36 37 struct qelem { 38 struct qelem *q_forw; 39 struct qelem *q_back; 40 }; 41 42 void 43 insque(entry, pred) 44 void *entry; 45 void *pred; 46 { 47 struct qelem *e = (struct qelem *) entry; 48 struct qelem *p = (struct qelem *) pred; 49 50 _DIAGASSERT(e != 0); 51 52 e->q_back = p; 53 if (p) { 54 e->q_forw = p->q_forw; 55 if (p->q_forw) 56 p->q_forw->q_back = e; 57 p->q_forw = e; 58 } else 59 e->q_forw = 0; 60 } 61