/*
  +----------------------------------------------------------------------+
  | APC                                                                  |
  +----------------------------------------------------------------------+
  | Copyright (c) 2006 The PHP Group                                     |
  +----------------------------------------------------------------------+
  | This source file is subject to version 3.01 of the PHP license,      |
  | that is bundled with this package in the file LICENSE, and is        |
  | available through the world-wide-web at the following url:           |
  | http://www.php.net/license/3_01.txt                                  |
  | If you did not receive a copy of the PHP license and are unable to   |
  | obtain it through the world-wide-web, please send a note to          |
  | license@php.net so we can mail you a copy immediately.               |
  +----------------------------------------------------------------------+
  | Authors: Brian Shire <shire@php.net>                                 |
  +----------------------------------------------------------------------+

 */

/* $Id: atomic.h,v 1.1 2006/09/29 07:13:01 shire Exp $ */


#include <sys/syscall.h>
#include <sys/time.h>
#include <linux/futex.h>

/* int sys_futex (void *futex, int op, int val, const struct timespec *timeout); */
static inline long int apc_sys_futex(void *futex, int op, int val, const struct timespec *timeout) {

  long int ret;

  /* i386 system calls are performed with nt 80h operation.
   *  the argument order is a, b, c, d, S, D  
   */ 
  asm volatile ("int $0x80" 
       : "=a" (ret)
       : "0" (SYS_futex), 
         "b" (futex), 
         "c" (op), 
         "d" (val),
         "S" (timeout)
       : "memory"
      );

  return ret;

} 


static inline int apc_cmpxchg(volatile int *ptr, int old, int new) {

    int prev;

    asm volatile ("LOCK cmpxchgl %1, %2"
                   : "=a" (prev)
                   : "r" (new), 
                     "m" (*(ptr)), 
                     "0"(old)
                   : "memory", "cc"
                 );

    return prev;
}

static inline int apc_xchg(volatile int *ptr, int new) {

  int ret;
  
  asm volatile ("LOCK xchgl %[new], %[ptr]"
                : "=a" (ret)
                : [new] "0" (new), 
                  [ptr] "m" (*(ptr))
                : "memory"
               );

  return ret;
  
}