atomicity.h

Glibc 2.3.2源代码(解压后有100多M)

/* Low-level functions for atomic operations.  Sparc64 version.
   Copyright (C) 1999 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 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; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _ATOMICITY_H
#define _ATOMICITY_H	1

#include <inttypes.h>

static inline int
__attribute__ ((unused))
exchange_and_add (volatile uint32_t *mem, int val)
{
  uint32_t tmp1, tmp2;

  __asm__ __volatile__("1:	lduw	[%2], %0\n\t"
		       "	add	%0, %3, %1\n\t"
		       "	cas	[%2], %0, %1\n\t"
		       "	sub	%0, %1, %0\n\t"
		       "	brnz,pn	%0, 1b\n\t"
		       "	 nop"
		       : "=&r" (tmp1), "=&r" (tmp2)
		       : "r" (mem), "r" (val)
		       : "memory");
  return tmp2;
}

static inline void
__attribute__ ((unused))
atomic_add (volatile uint32_t *mem, int val)
{
  uint32_t tmp1, tmp2;

  __asm__ __volatile__("1:	lduw	[%2], %0\n\t"
		       "	add	%0, %3, %1\n\t"
		       "	cas	[%2], %0, %1\n\t"
		       "	sub	%0, %1, %0\n\t"
		       "	brnz,pn	%0, 1b\n\t"
		       "	 nop"
		       : "=&r" (tmp1), "=&r" (tmp2)
		       : "r" (mem), "r" (val)
		       : "memory");
}

static inline int
__attribute__ ((unused))
compare_and_swap (volatile long int *p, long int oldval, long int newval)
{
  register long int tmp, tmp2;

  __asm__ __volatile__("1:	ldx	[%4], %0\n\t"
		       "	mov	%2, %1\n\t"
		       "	cmp	%0, %3\n\t"
		       "	bne,a,pn %%xcc, 2f\n\t"
		       "	 mov	0, %0\n\t"
		       "	casx	[%4], %0, %1\n\t"
		       "	sub	%0, %1, %0\n\t"
		       "	brnz,pn	%0, 1b\n\t"
		       "	 mov	1, %0\n\t"
		       "2:"
		       : "=&r" (tmp), "=&r" (tmp2)
		       : "r" (newval), "r" (oldval), "r" (p)
		       : "memory");
  return tmp;
}

#endif /* atomicity.h */