sys/sys/mutex.h

   1 /*
   2  * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #ifndef _SYS_MUTEX_H_
  36 #define _SYS_MUTEX_H_
  37
  38 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
  39
  40 #ifndef _SYS_TYPES_H_
  41 #include <sys/types.h>
  42 #endif
  43 #ifndef _MACHINE_ATOMIC_H_
  44 #include <machine/atomic.h>
  45 #endif
  46 #ifndef _MACHINE_CPUFUNC_H_
  47 #include <machine/cpufunc.h>
  48 #endif
  49
  50 /*
  51  * The general mutex structure provides recursive shared and exclusive
  52  * locks, downgrade, a non-blocking upgrade, and various other functions.
  53  *
  54  * The structure is 16-byte aligned and either 16 or 32 bytes, designed
  55  * for 32 or 64 bit cpus.
  56  */
  57 struct thread;
  58
  59 struct mtx_link {
  60         struct mtx_link *next;
  61         struct mtx_link *prev;
  62         struct thread   *owner;
  63         int             state;
  64 };
  65
  66 typedef struct mtx_link *mtx_link_t;
  67
  68 struct mtx {
  69         volatile u_int  mtx_lock;
  70         int             mtx_refs;
  71         struct thread   *mtx_owner;
  72         mtx_link_t      mtx_link;
  73 } __cachealign;
  74
  75 typedef struct mtx *mtx_t;
  76
  77 #define MTX_EXCLUSIVE   0x80000000
  78 #define MTX_SHWANTED    0x40000000
  79 #define MTX_EXWANTED    0x20000000
  80 #define MTX_EXLINK      0x10000000
  81 #define MTX_MASK        0x0FFFFFFF
  82
  83 #define MTX_PCATCH      0x00000001
  84
  85 #define MTX_OWNER_NONE  NULL
  86 #define MTX_OWNER_ANON  (struct thread *)-2)
  87
  88 #define MTX_LINK_IDLE           0
  89 #define MTX_LINK_ABORTED        -1
  90 #define MTX_LINK_LINKED         1
  91 #define MTX_LINK_ACQUIRED       2
  92
  93 #endif
  94
  95 /*
  96  * See also sys/mutex2.h
  97  */
  98 #ifdef _KERNEL
  99
 100 int     _mtx_lock_ex_link(mtx_t mtx, mtx_link_t link, const char *ident, int flags, int to);
 101 int     _mtx_lock_ex(mtx_t mtx, const char *ident, int flags, int to);
 102 int     _mtx_lock_sh(mtx_t mtx, const char *ident, int flags, int to);
 103 int     _mtx_lock_ex_quick(mtx_t mtx, const char *ident);
 104 int     _mtx_lock_sh_quick(mtx_t mtx, const char *ident);
 105 void    _mtx_spinlock_ex(mtx_t mtx);
 106 void    _mtx_spinlock_sh(mtx_t mtx);
 107 int     _mtx_lock_ex_try(mtx_t mtx);
 108 int     _mtx_lock_sh_try(mtx_t mtx);
 109 void    _mtx_downgrade(mtx_t mtx);
 110 int     _mtx_upgrade_try(mtx_t mtx);
 111 void    _mtx_unlock(mtx_t mtx);
 112 void    mtx_abort_ex_link(mtx_t mtx, mtx_link_t link);
 113
 114 #endif
 115
 116 #endif