diff options
Diffstat (limited to 'libpthread/sysdeps/ia32/bits/atomic.h')
-rw-r--r-- | libpthread/sysdeps/ia32/bits/atomic.h | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/libpthread/sysdeps/ia32/bits/atomic.h b/libpthread/sysdeps/ia32/bits/atomic.h new file mode 100644 index 00000000..0dfc1f60 --- /dev/null +++ b/libpthread/sysdeps/ia32/bits/atomic.h @@ -0,0 +1,66 @@ +/* Atomic operations. i386 version. + Copyright (C) 2000 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library 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; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#ifndef _BITS_ATOMIC_H +#define _BITS_ATOMIC_H 1 + +typedef __volatile int __atomic_t; + +static inline void +__atomic_inc (__atomic_t *__var) +{ + __asm__ __volatile ("lock; incl %0" : "=m" (*__var) : "m" (*__var)); +} + +static inline void +__atomic_dec (__atomic_t *__var) +{ + __asm__ __volatile ("lock; decl %0" : "=m" (*__var) : "m" (*__var)); +} + +static inline int +__atomic_dec_and_test (__atomic_t *__var) +{ + unsigned char __ret; + + __asm__ __volatile ("lock; decl %0; sete %1" + : "=m" (*__var), "=qm" (__ret) : "m" (*__var)); + return __ret != 0; +} + +/* We assume that an __atomicptr_t is only used for pointers to + word-aligned objects, and use the lowest bit for a simple lock. */ +typedef __volatile int * __atomicptr_t; + +/* Actually we don't implement that yet, and assume that we run on + something that has the i486 instruction set. */ +static inline int +__atomicptr_compare_and_swap (__atomicptr_t *__ptr, void *__oldval, + void * __newval) +{ + char __ret; + int __dummy; + + __asm__ __volatile ("lock; cmpxchgl %3, %1; sete %0" + : "=q" (__ret), "=m" (*__ptr), "=a" (__dummy) + : "r" (__newval), "m" (*__ptr), "a" (__oldval)); + return __ret; +} + +#endif |