pthreads/pthread_spinlock.h

   1 /*
   2  * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright 1996 1995 by Open Software Foundation, Inc. 1997 1996 1995 1994 1993 1992 1991
  27  *              All Rights Reserved
  28  *
  29  * Permission to use, copy, modify, and distribute this software and
  30  * its documentation for any purpose and without fee is hereby granted,
  31  * provided that the above copyright notice appears in all copies and
  32  * that both the copyright notice and this permission notice appear in
  33  * supporting documentation.
  34  *
  35  * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
  36  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  37  * FOR A PARTICULAR PURPOSE.
  38  *
  39  * IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
  40  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  41  * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
  42  * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
  43  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  44  *
  45  */
  46 /*
  47  * MkLinux
  48  */
  49
  50 /*
  51  * POSIX Threads - IEEE 1003.1c
  52  */
  53
  54 #ifndef _POSIX_PTHREAD_SPINLOCK_H
  55 #define _POSIX_PTHREAD_SPINLOCK_H
  56
  57 #include <mach/mach.h>
  58 #define __APPLE_API_PRIVATE
  59 #include <machine/cpu_capabilities.h>
  60
  61 #ifndef __POSIX_LIB__
  62 #define __POSIX_LIB__
  63 #endif
  64
  65 #include "pthread_machdep.h"            /* Machine-dependent definitions. */
  66
  67 /* Number of times to spin when the lock is unavailable and we are on a
  68    multiprocessor.  On a uniprocessor we yield the processor immediately.  */
  69 #define MP_SPIN_TRIES   1000
  70 extern int _spin_tries;
  71 extern int __is_threaded;
  72
  73 /* Internal mutex locks for data structures */
  74 #define TRY_LOCK(v) (!__is_threaded || _spin_lock_try((pthread_lock_t *)&(v)))
  75
  76 /* _DO_SPINLOCK_LOCK() takes a (pthread_lock_t *) */
  77 #define _DO_SPINLOCK_LOCK(v) _spin_lock(v)
  78
  79 /* _DO_SPINLOCK_UNLOCK() takes a (pthread_lock_t *) */
  80 #define _DO_SPINLOCK_UNLOCK(v)  _spin_unlock(v)
  81
  82 /* LOCK() takes a (pthread_lock_t) */
  83 #define LOCK(v)                                                         \
  84     do {                                                                \
  85         if (__is_threaded) {                                            \
  86             _DO_SPINLOCK_LOCK((pthread_lock_t *)&(v));                  \
  87         }                                                               \
  88     } while (0)
  89
  90 /* UNLOCK() takes a (pthread_lock_t) */
  91 #define UNLOCK(v)                                                       \
  92     do {                                                                \
  93         if (__is_threaded) {                                            \
  94             _DO_SPINLOCK_UNLOCK((pthread_lock_t *)&(v));                \
  95         }                                                               \
  96     } while (0)
  97
  98 /* Prototypes. */
  99
 100 /* Functions defined in machine-dependent files. */
 101 extern void _spin_lock(pthread_lock_t *lockp);
 102 extern int _spin_lock_try(pthread_lock_t *lockp);
 103 extern void _spin_unlock(pthread_lock_t *lockp);
 104
 105 #endif /* _POSIX_PTHREAD_SPINLOCK_H */