pthreads/pthread_spinlock.h

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