diff options
Diffstat (limited to 'libpthread/linuxthreads/sysdeps/i386/i686/pt-machine.h')
-rw-r--r-- | libpthread/linuxthreads/sysdeps/i386/i686/pt-machine.h | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/libpthread/linuxthreads/sysdeps/i386/i686/pt-machine.h b/libpthread/linuxthreads/sysdeps/i386/i686/pt-machine.h new file mode 100644 index 000000000..2e52abe2e --- /dev/null +++ b/libpthread/linuxthreads/sysdeps/i386/i686/pt-machine.h @@ -0,0 +1,78 @@ +/* Machine-dependent pthreads configuration and inline functions. + i686 version. + Copyright (C) 1996-2001, 2002, 2003 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Richard Henderson <rth@tamu.edu>. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; see the file COPYING.LIB. If + not, see <http://www.gnu.org/licenses/>. */ + +#ifndef _PT_MACHINE_H +#define _PT_MACHINE_H 1 + +#ifndef PT_EI +# define PT_EI __extern_always_inline +#endif +#include <bits/kernel-features.h> + +#ifndef __ASSEMBLER__ +extern long int testandset (int *spinlock); +extern int __compare_and_swap (long int *p, long int oldval, long int newval); + +/* Get some notion of the current stack. Need not be exactly the top + of the stack, just something somewhere in the current frame. */ +#define CURRENT_STACK_FRAME __builtin_frame_address (0) + + +/* Spinlock implementation; required. */ +PT_EI long int +testandset (int *spinlock) +{ + long int ret; + + __asm__ __volatile__ ( + "xchgl %0, %1" + : "=r" (ret), "=m" (*spinlock) + : "0" (1), "m" (*spinlock) + : "memory"); + + return ret; +} + + +/* Compare-and-swap for semaphores. It's always available on i686. */ +#define HAS_COMPARE_AND_SWAP + +PT_EI int +__compare_and_swap (long int *p, long int oldval, long int newval) +{ + char ret; + long int readval; + + __asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0" + : "=q" (ret), "=m" (*p), "=a" (readval) + : "r" (newval), "m" (*p), "a" (oldval) + : "memory"); + return ret; +} +#endif + +#if __ASSUME_LDT_WORKS > 0 +#include "../useldt.h" +#endif + +/* The P4 and above really want some help to prevent overheating. */ +#define BUSY_WAIT_NOP __asm__ ("rep; nop") + +#endif /* pt-machine.h */ |