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 307c478bd9Sstevel@tonic-gate /* 317c478bd9Sstevel@tonic-gate * insque() and remque() insert or remove an element from a queue. 327c478bd9Sstevel@tonic-gate * The queue is built from a doubly linked list whose elements are 337c478bd9Sstevel@tonic-gate * defined by a structure where the first member of the structure 347c478bd9Sstevel@tonic-gate * points to the next element in the queue and the second member 357c478bd9Sstevel@tonic-gate * of the structure points to the previous element in the queue. 367c478bd9Sstevel@tonic-gate */ 377c478bd9Sstevel@tonic-gate 38*7257d1b4Sraf #pragma weak _insque = insque 39*7257d1b4Sraf #pragma weak _remque = remque 407c478bd9Sstevel@tonic-gate 41*7257d1b4Sraf #include "lint.h" 427c478bd9Sstevel@tonic-gate #include <sys/types.h> 437c478bd9Sstevel@tonic-gate #include <stdlib.h> 447c478bd9Sstevel@tonic-gate #include <search.h> 457c478bd9Sstevel@tonic-gate 467c478bd9Sstevel@tonic-gate void insque(void * elem,void * pred)477c478bd9Sstevel@tonic-gateinsque(void *elem, void *pred) 487c478bd9Sstevel@tonic-gate { 497c478bd9Sstevel@tonic-gate if (pred == NULL) { /* This is the first element being inserted. */ 507c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_forw = NULL; 517c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_back = NULL; 527c478bd9Sstevel@tonic-gate } else if (((struct qelem *)pred)->q_forw == NULL) { 537c478bd9Sstevel@tonic-gate /* The element is inserted at */ 547c478bd9Sstevel@tonic-gate /* the end of the queue. */ 557c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_forw = NULL; 567c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_back = pred; 577c478bd9Sstevel@tonic-gate ((struct qelem *)pred)->q_forw = elem; 587c478bd9Sstevel@tonic-gate } else { /* The element is inserted in the middle of */ 597c478bd9Sstevel@tonic-gate /* the queue. */ 607c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_forw = ((struct qelem *)pred)->q_forw; 617c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_back = pred; 627c478bd9Sstevel@tonic-gate ((struct qelem *)pred)->q_forw->q_back = elem; 637c478bd9Sstevel@tonic-gate ((struct qelem *)pred)->q_forw = elem; 647c478bd9Sstevel@tonic-gate } 657c478bd9Sstevel@tonic-gate } 667c478bd9Sstevel@tonic-gate 677c478bd9Sstevel@tonic-gate void remque(void * elem)687c478bd9Sstevel@tonic-gateremque(void *elem) 697c478bd9Sstevel@tonic-gate { 707c478bd9Sstevel@tonic-gate if (((struct qelem *)elem)->q_back == NULL) { 717c478bd9Sstevel@tonic-gate /* The first element is removed. */ 727c478bd9Sstevel@tonic-gate if (((struct qelem *)elem)->q_forw == NULL) 737c478bd9Sstevel@tonic-gate /* The only element is removed. */ 747c478bd9Sstevel@tonic-gate return; 757c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_forw->q_back = NULL; 767c478bd9Sstevel@tonic-gate } else if (((struct qelem *)elem)->q_forw == NULL) { 777c478bd9Sstevel@tonic-gate /* The last element is removed */ 787c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_back->q_forw = NULL; 797c478bd9Sstevel@tonic-gate } else { /* The middle element is removed. */ 807c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_back->q_forw = 81*7257d1b4Sraf ((struct qelem *)elem)->q_forw; 827c478bd9Sstevel@tonic-gate ((struct qelem *)elem)->q_forw->q_back = 83*7257d1b4Sraf ((struct qelem *)elem)->q_back; 847c478bd9Sstevel@tonic-gate } 857c478bd9Sstevel@tonic-gate } 86