#ifndef MPLIB1_BPO_LOCK_INTERNAL
#define MPLIB1_BPO_LOCK_INTERNAL
/*
*******************************************************************************
*  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/include/bpo_lock_internal.h,v $
*  $Author: mpoole $
*  $Date: 2002/10/07 09:37:49 $
*  $Revision: 1.2 $
*
*******************************************************************************
*
* Change History
*
* $Log: bpo_lock_internal.h,v $
* Revision 1.2  2002/10/07 09:37:49  mpoole
* Initial checkin of mplib1-3.1.0
*
* Revision 1.1  2002/10/07 09:36:50  mpoole
* Initial checkin of mplib1-3.1.0
*
*
*******************************************************************************
*/

#ident "$Header: /home/cvs/cvsroot/onelan/onelan/src/mplib1/include/bpo_lock_internal.h,v 1.2 2002/10/07 09:37:49 mpoole Exp $"
#ifndef MPLIB1_CONFIG
#include <mplib1/mplib1_config.h>
#endif
#ifndef MPLIB1_BPO_LOCK
#include <mplib1/bpo_lock.h>
#endif

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

/* ------------------------------------------------------------------
    structures
   ------------------------------------------------------------------ */

/* ------------------------------------------------------------------
    function definitions
   ------------------------------------------------------------------ */

/* Only one of the following ifdef blocks should be enabled */
#ifdef HAVE_LWP_MUTEX
#define Xchg(a)       _lwp_mutex_trylock(a)
#define Clr(a)        _lwp_mutex_unlock(a)
#endif

#ifdef HAVE_PTHREADS

/* No explicit defines needed */

#endif

#ifdef HAVE_MSEM
/* XPG4 varient */

/*#define Xchg(a) msem_lock(a,0)*/
/*#define Clr(a)  msem_unlock(a)*/

#endif

#ifdef HAVE_MUTEX

#define Xchg(a) acquire_lock(a)
#define Clr(a)  release_lock(a)
#define Lckval(a)	((long)(a->abi_lock))

#endif

#ifdef HAVE_SYS_ATOMIC
#include <sys/atomic.h>
#define Xchg(a)	atomic_xchg_long((long *)a,1)
#define Clr(a)	atomic_xchg_long((long *)a,0)
#define Lckval(a)	((long)(*(long *)a))

#endif

#ifdef HAVE_LINUX_BITOPS
#include <asm/bitops.h>
/* a more recent linux set of operations */
#define Xchg(a)		test_and_set_bit(0,a)
#define Clr(a)		test_and_clear_bit(0,a)
#define Lckval(a) 	test_bit(0,a)
#else
#ifdef HAVE_GCC_I386
/* The following was swiped from <asm/bitops.h> in the linux distribution */
/*
 * Some hacks to defeat gcc over-optimizations..
 */
struct __dummy { unsigned long a[100]; };
#define ADDR (*(struct __dummy *) addr)

__inline__ static int Xchg(volatile void * addr)
{
        int oldbit;

        __asm__ __volatile__("btsl %2,%1\n\tsbbl %0,%0"
                :"=r" (oldbit),"=m" (ADDR)
                :"r" (0));
        return oldbit;
}

__inline__ static int Clr( volatile void * addr)
{
        int oldbit;

        __asm__ __volatile__("btrl %2,%1\n\tsbbl %0,%0"
                :"=r" (oldbit),"=m" (ADDR)
                :"r" (0));
        return oldbit;
}


#define Lckval(a)	((long)(*a))
#endif
#endif

#ifdef HAVE_SVR4_I386
/* The following were grabbed from <sys/mp/mpmacros.h> on NCR 3000 */
asm int
Xchg(lp)
{
%       mem     lp;
        movl    lp,%eax
        xchgl   %eax,(%eax)
}

asm void
Clr(lp)
{
%       mem     lp;
        movl    lp,%eax
        movl    $0,(%eax)
%       reg     lp;
        movl    $0,(lp)
}

#define Lckval(a)	((long)(*a))
#endif

#ifdef HAVE_SVR4_I386B
/* The following was grabbed from <sys/atomic.h> on Sequent Ptx4.2.0 */
/*
 * atomic_xchg_long
 *
 * Atomically exchange the specified value with that at the specified
 * address, returning the old value.
 * The only reason for having both atomic_xchg_*() and atomic_xchg_u*()
 * primitives is to keep the compiler and lint happy without huge
 * numbers of error-hiding casts.
 *
 * Parameters:
 *      long *longptr;                  Address of long to exchange
 *      long newval;                    New value to exchange into *longptr.
 */

#ifdef __STDC__
__asm long atomic_xchg_long(volatile long *const longptr, long const newval)
#else
asm long atomic_xchg_long(longptr, newval)
#endif
{
%con longptr, newval;
        movl            longptr, %ecx   /* Get addr to known register.  */
        movl            newval, %eax    /* Get new value to known register. */
        xchgl           %eax, (%ecx)    /* Perform the exchange.        */
%con longptr; mem newval;
        movl            longptr, %ecx   /* Get addr to known register.  */
        movl            newval, %eax    /* Get new value to known register. */
        xchgl           %eax, (%ecx)    /* Perform the exchange.        */
%mem longptr; con newval;
        movl            longptr, %ecx   /* Get addr to known register.  */
        movl            newval, %eax    /* Get new value to known register. */
        xchgl           %eax, (%ecx)    /* Perform the exchange.        */
%mem longptr, newval;
        movl            longptr, %ecx   /* Get addr to known register.  */
        movl            newval, %eax    /* Get new value to known register. */
        xchgl           %eax, (%ecx)    /* Perform the exchange.        */
}
#define Xchg(a)	atomic_xchg_long((long *)a,1)
#define Clr(a)	atomic_xchg_long((long *)a,0)
#define Lckval(a)	((long)(*(long *)a))

#endif


#endif
/* -- End of File -- */