/*
 *	ttylock.h
 *	(c) 1997 by Fabrizio Polacco <fpolacco@debian.org>
 *	this header file is part of the lockdev library.
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU Library General Public
 *	License as published by the Free Software Foundation; version 2
 *	dated June, 1991.
 *
 *	This program is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU General Public License for more details.
 *
 *	You should have received a copy of the GNU Library General
 *	Public License along with this program;  if not, write to the
 *	Free Software Foundation, Inc., 675 Mass Ave., Cambridge, MA
 *	02139, USA.
 *
 *	This header file provides an alternative API to the services of
 *	the lockdev library, the same API implemented by AIX.
 *	It is intended as a quick help for any program originally
 *	designed for the AIX that wants to move to lockdev.
 *
 */

#ifndef _TTYLOCK_H_
#define _TTYLOCK_H_

#ifdef	__cplusplus
extern "C" {
#endif

#ifndef	__P
#  if defined	(__STDC__) || defined (_AIX) \
		|| (defined (__mips) && defined (_SYSTYPE_SVR4)) \
		|| defined(WIN32) || defined(__cplusplus)
#    define	__P(protos) protos
#  else
#    define	__P(protos) ()
#  endif
#endif

#include <lockdev.h>


/* API of the library */

int	ttylock __P(( char * devname));
int	ttywait __P(( char * devname));
int	ttyunlock __P(( char * devname));
int	ttylocked __P(( char * devname));


static inline int
ttylock( devname)
	char * devname;
{
	/* should set errno ? */
	return( dev_lock( devname) == 0 ? 0 : -1);
}

static inline int
ttyunlock( devname)
	char * devname;
{
	return( dev_unlock( devname, 0));
}

static inline int
ttylocked( devname)
	char * devname;
{
	return( dev_testlock( devname) == 0 ? 0 : -1);
}

static inline int
ttywait( devname)
	char * devname;
{
	while( dev_testlock( devname)) {
		sleep(1);
	}
}


#ifdef	__cplusplus
};
#endif

#endif /* _TTYLOCK_H_ */