lib/libc/include/spinlock.h

   1 /*
   2  * Copyright (c) 1998 John Birrell <jb@cimlogic.com.au>.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by John Birrell.
  16  * 4. Neither the name of the author nor the names of any co-contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $FreeBSD: src/lib/libc/include/spinlock.h,v 1.4 1999/08/27 23:59:48 peter Exp $
  33  * $DragonFly: src/lib/libc/include/spinlock.h,v 1.4 2005/01/31 22:29:29 dillon Exp $
  34  *
  35  * Lock definitions used in both libc and libpthread.
  36  *
  37  */
  38
  39 #ifndef _SPINLOCK_H_
  40 #define _SPINLOCK_H_
  41 #include <sys/cdefs.h>
  42 #include <sys/types.h>
  43
  44 /*
  45  * Lock structure with room for debugging information.
  46  */
  47 typedef struct {
  48         volatile long   access_lock;
  49         volatile long   lock_owner;
  50         volatile char   *fname;
  51         volatile int    lineno;
  52 } spinlock_t;
  53
  54 #define _SPINLOCK_INITIALIZER   { 0, 0, 0, 0 }
  55
  56 #define _SPINUNLOCK(_lck)       _spinunlock(_lck)
  57 #ifdef  _LOCK_DEBUG
  58 #define _SPINLOCK(_lck)         _spinlock_debug(_lck, __FILE__, __LINE__)
  59 #else
  60 #define _SPINLOCK(_lck)         _spinlock(_lck)
  61 #endif
  62
  63 /*
  64  * Thread function prototype definitions:
  65  */
  66 __BEGIN_DECLS
  67 long    _atomic_lock (volatile long *);
  68 void    _spinlock (spinlock_t *);
  69 void    _spinlock_debug (spinlock_t *, char *, int);
  70 void    _spinunlock (spinlock_t *);
  71 __END_DECLS
  72
  73 #endif /* _SPINLOCK_H_ */