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 #include <machine/atomic.h>
  44 #include <machine/cpufunc.h>
  45
  46 /*
  47  * The general mutex structure provides recursive shared and exclusive
  48  * locks, downgrade, a non-blocking upgrade, and various other functions.
  49  *
  50  * The structure is 16-byte aligned and either 16 or 32 bytes, designed
  51  * for 32 or 64 bit cpus.
  52  */
  53 struct thread;
  54
  55 struct mtx_link {
  56         struct mtx_link *next;
  57         struct mtx_link *prev;
  58         struct thread   *owner;
  59         int             state;
  60         void            (*callback)(struct mtx_link *, void *arg, int error);
  61         void            *arg;
  62 };
  63
  64 typedef struct mtx_link mtx_link_t;
  65
  66 struct mtx {
  67         volatile u_int  mtx_lock;
  68         int             mtx_reserved01; /* future use & struct alignmnent */
  69         struct thread   *mtx_owner;
  70         mtx_link_t      *mtx_exlink;
  71         mtx_link_t      *mtx_shlink;
  72         const char      *mtx_ident;
  73 } __cachealign;
  74
  75 typedef struct mtx      mtx_t;
  76 typedef u_int           mtx_state_t;
  77
  78 #define MTX_INITIALIZER(ident)  { .mtx_lock = 0, .mtx_owner = NULL, \
  79                                   .mtx_exlink = NULL, .mtx_shlink = NULL, \
  80                                   .mtx_ident = ident }
  81
  82 #define MTX_EXCLUSIVE   0x80000000
  83 #define MTX_SHWANTED    0x40000000
  84 #define MTX_EXWANTED    0x20000000
  85 #define MTX_LINKSPIN    0x10000000
  86 #define MTX_MASK        0x0FFFFFFF
  87
  88 #define MTX_OWNER_NONE  NULL
  89 #define MTX_OWNER_ANON  ((struct thread *)-2)
  90
  91 #define MTX_LINK_IDLE           0
  92 #define MTX_LINK_LINKED_SH      (MTX_LINK_LINKED | 1)
  93 #define MTX_LINK_LINKED_EX      (MTX_LINK_LINKED | 2)
  94 #define MTX_LINK_ACQUIRED       3
  95 #define MTX_LINK_CALLEDBACK     4
  96 #define MTX_LINK_ABORTED        5
  97
  98 #define MTX_LINK_LINKED         0x1000
  99
 100 #endif
 101
 102 /*
 103  * See also sys/mutex2.h
 104  */
 105 #ifdef _KERNEL
 106
 107 int     _mtx_lock_ex_link(mtx_t *mtx, mtx_link_t *link, int flags, int to);
 108 int     _mtx_lock_ex(mtx_t *mtx, int flags, int to);
 109 int     _mtx_lock_sh_link(mtx_t *mtx, mtx_link_t *link, int flags, int to);
 110 int     _mtx_lock_sh(mtx_t *mtx, int flags, int to);
 111 int     _mtx_lock_ex_quick(mtx_t *mtx);
 112 int     _mtx_lock_sh_quick(mtx_t *mtx);
 113 void    _mtx_spinlock(mtx_t *mtx);
 114 int     _mtx_spinlock_try(mtx_t *mtx);
 115 int     _mtx_lock_ex_try(mtx_t *mtx);
 116 int     _mtx_lock_sh_try(mtx_t *mtx);
 117 void    _mtx_downgrade(mtx_t *mtx);
 118 int     _mtx_upgrade_try(mtx_t *mtx);
 119 void    _mtx_unlock(mtx_t *mtx);
 120 void    mtx_abort_link(mtx_t *mtx, mtx_link_t *link);
 121 int     mtx_wait_link(mtx_t *mtx, mtx_link_t *link, int flags, int to);
 122
 123 #endif
 124
 125 #endif