17c478bd9Sstevel@tonic-gate /* 27c478bd9Sstevel@tonic-gate * CDDL HEADER START 37c478bd9Sstevel@tonic-gate * 47c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*7257d1b4Sraf * Common Development and Distribution License (the "License"). 6*7257d1b4Sraf * You may not use this file except in compliance with the License. 77c478bd9Sstevel@tonic-gate * 87c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 97c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 107c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions 117c478bd9Sstevel@tonic-gate * and limitations under the License. 127c478bd9Sstevel@tonic-gate * 137c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 147c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 157c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 167c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 177c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 187c478bd9Sstevel@tonic-gate * 197c478bd9Sstevel@tonic-gate * CDDL HEADER END 207c478bd9Sstevel@tonic-gate */ 21*7257d1b4Sraf 227c478bd9Sstevel@tonic-gate /* 23*7257d1b4Sraf * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 247c478bd9Sstevel@tonic-gate * Use is subject to license terms. 257c478bd9Sstevel@tonic-gate */ 267c478bd9Sstevel@tonic-gate 277c478bd9Sstevel@tonic-gate /* Copyright (c) 1988 AT&T */ 287c478bd9Sstevel@tonic-gate /* All Rights Reserved */ 297c478bd9Sstevel@tonic-gate 30*7257d1b4Sraf #pragma ident "%Z%%M% %I% %E% SMI" 317c478bd9Sstevel@tonic-gate 327c478bd9Sstevel@tonic-gate /* 337c478bd9Sstevel@tonic-gate * insque() and remque() insert or remove an element from a queue. 347c478bd9Sstevel@tonic-gate * The queue is built from a doubly linked list whose elements are 357c478bd9Sstevel@tonic-gate * defined by a structure where the first member of the structure 367c478bd9Sstevel@tonic-gate * points to the next element in the queue and the second member 377c478bd9Sstevel@tonic-gate * of the structure points to the previous element in the queue. 387c478bd9Sstevel@tonic-gate */ 397c478bd9Sstevel@tonic-gate 40*7257d1b4Sraf #pragma weak _insque = insque 41*7257d1b4Sraf #pragma weak _remque = remque 427c478bd9Sstevel@tonic-gate 43*7257d1b4Sraf #include "lint.h" 447c478bd9Sstevel@tonic-gate #include <sys/types.h> 457c478bd9Sstevel@tonic-gate #include <stdlib.h> 467c478bd9Sstevel@tonic-gate #include <search.h> 477c478bd9Sstevel@tonic-gate 487c478bd9Sstevel@tonic-gate void insque(void * elem,void * pred)497c478bd9Sstevel@tonic-gateinsque(void *elem, void *pred) 507c478bd9Sstevel@tonic-gate { 517c478bd9Sstevel@tonic-gate if (pred == NULL) { /* This is the first element being inserted. */ 527c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_forw = NULL; 537c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_back = NULL; 547c478bd9Sstevel@tonic-gate } else if (((struct qelem *)pred)->q_forw == NULL) { 557c478bd9Sstevel@tonic-gate /* The element is inserted at */ 567c478bd9Sstevel@tonic-gate /* the end of the queue. */ 577c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_forw = NULL; 587c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_back = pred; 597c478bd9Sstevel@tonic-gate ((struct qelem *)pred)->q_forw = elem; 607c478bd9Sstevel@tonic-gate } else { /* The element is inserted in the middle of */ 617c478bd9Sstevel@tonic-gate /* the queue. */ 627c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_forw = ((struct qelem *)pred)->q_forw; 637c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_back = pred; 647c478bd9Sstevel@tonic-gate ((struct qelem *)pred)->q_forw->q_back = elem; 657c478bd9Sstevel@tonic-gate ((struct qelem *)pred)->q_forw = elem; 667c478bd9Sstevel@tonic-gate } 677c478bd9Sstevel@tonic-gate } 687c478bd9Sstevel@tonic-gate 697c478bd9Sstevel@tonic-gate void remque(void * elem)707c478bd9Sstevel@tonic-gateremque(void *elem) 717c478bd9Sstevel@tonic-gate { 727c478bd9Sstevel@tonic-gate if (((struct qelem *)elem)->q_back == NULL) { 737c478bd9Sstevel@tonic-gate /* The first element is removed. */ 747c478bd9Sstevel@tonic-gate if (((struct qelem *)elem)->q_forw == NULL) 757c478bd9Sstevel@tonic-gate /* The only element is removed. */ 767c478bd9Sstevel@tonic-gate return; 777c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_forw->q_back = NULL; 787c478bd9Sstevel@tonic-gate } else if (((struct qelem *)elem)->q_forw == NULL) { 797c478bd9Sstevel@tonic-gate /* The last element is removed */ 807c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_back->q_forw = NULL; 817c478bd9Sstevel@tonic-gate } else { /* The middle element is removed. */ 827c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_back->q_forw = 837c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_forw; 847c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_forw->q_back = 857c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_back; 867c478bd9Sstevel@tonic-gate } 877c478bd9Sstevel@tonic-gate } 88