/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
*          Copyright (c) 2020-2023 Contributors to ksh 93u+m           *
*                      and is licensed under the                       *
*                 Eclipse Public License, Version 2.0                  *
*                                                                      *
*                A copy of the License is available at                 *
*      https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html      *
*         (with md5 checksum 84283fa8859daf213bdda5a9f8d1be1d)         *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                   Phong Vo <kpv@research.att.com>                    *
*                  Martijn Dekker <martijn@inlv.org>                   *
*                                                                      *
***********************************************************************/

#include	"vmhdr.h"

/*	Change the discipline for a region.  The old discipline
**	is returned.  If the new discipline is NULL then the
**	discipline is not changed.
**
**	Written by Kiem-Phong Vo, kpv@research.att.com, 01/16/94.
*/
Vmdisc_t* vmdisc(Vmalloc_t* vm, Vmdisc_t* disc)
{
	Vmdisc_t*	old = vm->disc;

	if(disc)
	{	if(old->exceptf &&
		   (*old->exceptf)(vm,VM_DISC,disc,old) != 0 )
			return NULL;
		vm->disc = disc;
	}
	return old;
}
