text: /*-
   * Copyright (c) 2010 Isilon Systems, Inc.
   * Copyright (c) 2010 iX Systems, Inc.
   * Copyright (c) 2010 Panasas, Inc.
   * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice unmodified, this list of conditions, and the following
   *    disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * $FreeBSD$
   */
  #ifndef	_ATOMIC_LONG_H_
  #define	_ATOMIC_LONG_H_
  
  #include <sys/cdefs.h>
  #include <sys/types.h>
  #include <machine/atomic.h>
  
  #define	ATOMIC_LONG_INIT(x)	{ .counter = (x) }
  
  typedef struct {
  	volatile long counter;
  } atomic_long_t;
  
  #define	atomic_long_add(i, v)		atomic_long_add_return((i), (v))
  #define	atomic_long_inc_return(v)	atomic_long_add_return(1, (v))
  #define	atomic_long_inc_not_zero(v)	atomic_long_add_unless((v), 1, 0)
  
  static inline long
  atomic_long_add_return(long i, atomic_long_t *v)
  {
  	return i + atomic_fetchadd_long(&v->counter, i);
  }
  
  static inline void
  atomic_long_set(atomic_long_t *v, long i)
  {
  	atomic_store_rel_long(&v->counter, i);
  }
  
  static inline long
  atomic_long_read(atomic_long_t *v)
  {
  	return atomic_load_acq_long(&v->counter);
  }
  
  static inline long
  atomic_long_inc(atomic_long_t *v)
  {
  	return atomic_fetchadd_long(&v->counter, 1) + 1;
  }
  
  static inline long
  atomic_long_dec(atomic_long_t *v)
  {
  	return atomic_fetchadd_long(&v->counter, -1) - 1;
  }
  
  static inline int
  atomic_long_add_unless(atomic_long_t *v, long a, long u)
  {
  	long c;
  
  	for (;;) {
  		c = atomic_long_read(v);
  		if (unlikely(c == u))
  			break;
  		if (likely(atomic_cmpset_long(&v->counter, c, c + a)))
  			break;
  	}
  	return (c != u);
  }
  
  static inline long
  atomic_long_dec_and_test(atomic_long_t *v)
  {
  	long i = atomic_long_add(-1, v);
  	return i == 0 ;
  }
  
  #endif	/* _ATOMIC_LONG_H_ */
  