/*
*******************************************************************************
*  Copyright (c) 1996 Martin Poole
*******************************************************************************
**
** WARNING !!  WARNING !! WARNING !! WARNING !! WARNING !! WARNING !!
**
** Any changes to be made to this file should first be checked with
** mplib1 source control for library integrity.
**
** mplib1 source control can be reached at  mplib1@quatermass.co.uk
** 
*
*  $Source: /home/cvs/cvsroot/onelan/onelan/src/mplib1/libsrc/bpo_l_003.c,v $
*  $Author: mpoole $
*  $Date: 2002/10/07 09:37:36 $
*  $Revision: 1.2 $
*
*******************************************************************************
*
* Change History
*
* $Log: bpo_l_003.c,v $
* Revision 1.2  2002/10/07 09:37:36  mpoole
* Initial checkin of mplib1-3.1.0
*
* Revision 1.1  2002/10/07 09:36:53  mpoole
* Initial checkin of mplib1-3.1.0
*
*
*******************************************************************************
*/

#ident "$Header: /home/cvs/cvsroot/onelan/onelan/src/mplib1/libsrc/bpo_l_003.c,v 1.2 2002/10/07 09:37:36 mpoole Exp $"

/* ------------------------------------------------------------------
    Include files
   ------------------------------------------------------------------ */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/ipc.h>
#include <sys/shm.h>

#include <mplib1/mplib1_config.h>
#include <mplib1/bpo_lock.h>
#include <mplib1/bpo_list.h>
#include <include/bpo_list_internal.h>
#include <mplib1/bpo_init.h>

/* ------------------------------------------------------------------
    defines
   ------------------------------------------------------------------ */

/* ------------------------------------------------------------------
    Code starts here
   ------------------------------------------------------------------ */

bpo_Node_t *
bpo_Remove_List_Node( bpo_List_t *lp, bpo_Node_t *node1 )
{
    bpo_Node_t *nnode,*pnode;
    void *base;

    /* Ensure we have a list that is in shared, and that the
	supplied node is in the same shared segment.
    */
    if (   lp
	&& (base = Get_SODB_Base( lp ))
	&& (base == Get_SODB_Base( node1 ))
       )
    {
	/* Lock the list whilst we test the proerties of it and the node */
	bpo_pid_Lock( &lp->lno_Pid_Lock );

	/* Does the node look valid ?
	    It should have forward and back offsets
	    and should be in the designated list
	*/
	if (   node1->lno_Succ
	    && node1->lno_Pred
	    && node1->lno_List
	    && (node1->lno_List == lp->lno_me)
	   )
	{
	    /* get pointers to the surrounding nodes */
	    nnode = GNNODE( node1, node1->lno_Succ );
	    pnode = GNNODE( node1, node1->lno_Pred );
	    /* relink the list around the node we are removing */
	    if (nnode && nnode->lno_Pred == node1->lno_me)
		nnode->lno_Pred = node1->lno_Pred;
	    if (pnode && pnode->lno_Succ == node1->lno_me)
		pnode->lno_Succ = node1->lno_Succ;
	    /* do the list housekeeping */
	    lp->lno_count--;
	    lp->lno_serial_nbr++;
	    /* and clean up the node for next use */
	    node1->lno_Succ = 0;
	    node1->lno_Pred = 0;
	    node1->lno_List = 0;
	}else
	    node1=NULL;
	/* Unlock and off we go */
	bpo_pid_Unlock( &lp->lno_Pid_Lock );
    }else
	node1=NULL;
    return(node1);
}

bpo_Node_t *
bpo_Remove_Node( bpo_Node_t *node1 )
{
    return( bpo_Remove_List_Node( GRPTR( node1, node1->lno_List ), node1 ) );
}

/* -- End of File -- */