lib/libthread_xu/thread/thr_umtx.h

   1 /*-
   2  * Copyright (c) 2003 David Xu <davidxu@freebsd.org>
   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  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $DragonFly: src/lib/libthread_xu/thread/thr_umtx.h,v 1.5 2008/04/14 20:12:41 dillon Exp $
  27  */
  28
  29 #ifndef _THR_DFLY_UMTX_H_
  30 #define _THR_DFLY_UMTX_H_
  31
  32 #include <unistd.h>
  33
  34 #define UMTX_LOCKED     1
  35 #define UMTX_CONTESTED  2
  36
  37 typedef int umtx_t;
  38
  39 int     __thr_umtx_lock(volatile umtx_t *mtx, int timo);
  40 int     __thr_umtx_timedlock(volatile umtx_t *mtx,
  41                  const struct timespec *timeout);
  42 void    __thr_umtx_unlock(volatile umtx_t *mtx);
  43
  44 static inline void
  45 _thr_umtx_init(volatile umtx_t *mtx)
  46 {
  47     *mtx = 0;
  48 }
  49
  50 static inline int
  51 _thr_umtx_trylock(volatile umtx_t *mtx, int id __unused)
  52 {
  53     if (atomic_cmpset_acq_int(mtx, 0, 1))
  54         return (0);
  55     return (EBUSY);
  56 }
  57
  58 static inline int
  59 _thr_umtx_lock(volatile umtx_t *mtx, int id __unused)
  60 {
  61     if (atomic_cmpset_acq_int(mtx, 0, 1))
  62         return (0);
  63     return (__thr_umtx_lock(mtx, 0));
  64 }
  65
  66 static inline int
  67 _thr_umtx_timedlock(volatile umtx_t *mtx, int id __unused,
  68     const struct timespec *timeout)
  69 {
  70     if (atomic_cmpset_acq_int(mtx, 0, 1))
  71         return (0);
  72     return (__thr_umtx_timedlock(mtx, timeout));
  73 }
  74
  75 static inline void
  76 _thr_umtx_unlock(volatile umtx_t *mtx, int id __unused)
  77 {
  78     if (atomic_cmpset_acq_int(mtx, 1, 0))
  79         return;
  80     __thr_umtx_unlock(mtx);
  81 }
  82
  83 int _thr_umtx_wait(volatile umtx_t *mtx, umtx_t exp,
  84                    const struct timespec *timeout, int clockid);
  85 void _thr_umtx_wake(volatile umtx_t *mtx, int count);
  86
  87 #endif