1 /* Machine-specific definition for spin locks. Alpha version.
2 Copyright (C) 1994, 1997 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
20 #ifndef _MACHINE_LOCK_H
21 #define _MACHINE_LOCK_H
23 /* The type of a spin lock variable. */
25 typedef __volatile
long int __spin_lock_t
;
27 /* Value to initialize `__spin_lock_t' variables to. */
29 #define __SPIN_LOCK_INITIALIZER 0L
32 #ifndef _EXTERN_INLINE
33 #define _EXTERN_INLINE extern __inline
39 __spin_unlock (__spin_lock_t
*__lock
)
41 __asm__
__volatile__ ("mb; stq $31, %0; mb"
45 /* Try to lock LOCK; return nonzero if we locked it, zero if another has. */
48 __spin_try_lock (register __spin_lock_t
*__lock
)
50 register long int __rtn
, __tmp
;
54 __asm__
__volatile__ ("mb; ldq_l %0,%1" /* Load lock value into TMP. */
55 : "=r" (__tmp
) : "m" (*__lock
));
56 __rtn
= 2; /* Load locked value into RTN. */
58 /* The lock is already taken. */
61 /* The lock is not taken; try to get it now. */
62 __asm__
__volatile__ ("stq_c %0,%1"
63 : "=r" (__rtn
), "=m" (*__lock
)
64 : "0" (__rtn
), "1" (*__lock
));
65 /* RTN is clear if stq_c was interrupted; loop to try the lock again. */
67 /* RTN is now nonzero; we have the lock. */
71 /* Return nonzero if LOCK is locked. */
74 __spin_lock_locked (__spin_lock_t
*__lock
)
80 #endif /* machine-lock.h */