ghd_queue.c revision 507c32411f3f101e90ca2120f042b5ee698ba1d5
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 1999 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/types.h>
#include <sys/param.h>
#include <sys/debug.h>
#include "ghd_queue.h"
void
L1_add(L1_t *lp, L1el_t *lep, void *datap)
{
/* init the list element */
lep->le_nextp = NULL;
lep->le_datap = datap;
if (!lp->l1_tailp) {
/* list is empty */
lp->l1_headp = lep;
} else {
/* add it to the tailend */
lp->l1_tailp->le_nextp = lep;
}
lp->l1_tailp = lep;
}
/*
* L1Delete()
*
* Remove a specific entry from a singly-linked list.
*
*/
void
L1_delete(L1_t *lp, L1el_t *lep)
{
L1el_t *prevp;
if (lp->l1_headp == lep) {
/* it's the first entry in the list */
if ((lp->l1_headp = lep->le_nextp) == NULL) {
/* the list is now empty */
lp->l1_tailp = NULL;
}
return;
}
for (prevp = lp->l1_headp; prevp != NULL; prevp = prevp->le_nextp) {
if (prevp->le_nextp == lep) {
if ((prevp->le_nextp = lep->le_nextp) == NULL)
lp->l1_tailp = prevp;
return;
}
}
/* its not on this list */
}
/*
* L1_remove()
*
* Remove the entry at the head of the list (if any).
*
*/
void *
L1_remove(L1_t *lp)
{
L1el_t *lep;
/* pop the first one off the list head */
if ((lep = lp->l1_headp) == NULL) {
return (NULL);
}
/* if the list is now empty fix the tail pointer */
if ((lp->l1_headp = lep->le_nextp) == NULL)
lp->l1_tailp = NULL;
lep->le_nextp = NULL;
return (lep->le_datap);
}
void
L2_add(L2el_t *headp, L2el_t *elementp, void *private)
{
ASSERT(headp != NULL && elementp != NULL);
ASSERT(headp->l2_nextp != NULL);
ASSERT(headp->l2_prevp != NULL);
elementp->l2_private = private;
elementp->l2_nextp = headp;
elementp->l2_prevp = headp->l2_prevp;
headp->l2_prevp->l2_nextp = elementp;
headp->l2_prevp = elementp;
}
void
L2_delete(L2el_t *elementp)
{
ASSERT(elementp != NULL);
ASSERT(elementp->l2_nextp != NULL);
ASSERT(elementp->l2_prevp != NULL);
ASSERT(elementp->l2_nextp->l2_prevp == elementp);
ASSERT(elementp->l2_prevp->l2_nextp == elementp);
elementp->l2_prevp->l2_nextp = elementp->l2_nextp;
elementp->l2_nextp->l2_prevp = elementp->l2_prevp;
/* link it to itself in case someone does a double delete */
elementp->l2_nextp = elementp;
elementp->l2_prevp = elementp;
}
void
L2_add_head(L2el_t *headp, L2el_t *elementp, void *private)
{
ASSERT(headp != NULL && elementp != NULL);
ASSERT(headp->l2_nextp != NULL);
ASSERT(headp->l2_prevp != NULL);
elementp->l2_private = private;
elementp->l2_prevp = headp;
elementp->l2_nextp = headp->l2_nextp;
headp->l2_nextp->l2_prevp = elementp;
headp->l2_nextp = elementp;
}
/*
* L2_remove()
*
* Remove the entry from the head of the list (if any).
*
*/
void *
L2_remove_head(L2el_t *headp)
{
L2el_t *elementp;
ASSERT(headp != NULL);
if (L2_EMPTY(headp))
return (NULL);
elementp = headp->l2_nextp;
headp->l2_nextp = elementp->l2_nextp;
elementp->l2_nextp->l2_prevp = headp;
/* link it to itself in case someone does a double delete */
elementp->l2_nextp = elementp;
elementp->l2_prevp = elementp;
return (elementp->l2_private);
}
void *
L2_next(L2el_t *elementp)
{
ASSERT(elementp != NULL);
if (L2_EMPTY(elementp))
return (NULL);
return (elementp->l2_nextp->l2_private);
}