.\" $OpenBSD: insque.3,v 1.6 2005/07/26 04:20:23 jaredy Exp $ .\" Copyright (c) 1993 John Brezak .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. The name of the author may be used to endorse or promote products .\" derived from this software without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" .Dd August 12, 1993 .Dt INSQUE 3 .Os .Sh NAME .Nm insque , .Nm remque .Nd insert/remove element from a queue .Sh SYNOPSIS .Fd #include .Ft void .Fn insque "void *elem" "void *pred" .Ft void .Fn remque "void *elem" .Sh DESCRIPTION .Bf -symbolic These interfaces have been superceded by the .Xr queue 3 macros and are provided for compatibility with legacy code. .Ef .Pp .Fn insque and .Fn remque manipulate queues built from doubly linked lists. The queue can be either circular or linear. Each element in the queue must be of the following form: .Bd -literal -offset indent struct qelem { struct qelem *q_forw; struct qelem *q_back; char q_data[]; }; .Ed .Pp The first two elements in the struct must be pointers of the same type that point to the previous and next elements in the queue respectively. Any subsequent data in the struct is application-dependent. .Pp The .Fn insque function inserts .Fa elem into a queue immediately after .Fa pred . .Pp The .Fn remque function removes .Fa elem from the queue. .Pp These functions are not atomic unless that machine architecture allows it. .Sh SEE ALSO .Xr queue 3 .Sh STANDARDS The .Fn insque and .Fn remque functions conform to the .St -p1003.1-2001 and .St -xpg4.3 specifications. .Sh HISTORY The .Fn insque and .Fn remque functions are derived from the .Li insque and .Li remque instructions on the .Tn VAX . They first appeared in .Bx 4.2 .