2 * Copyright (c) 2009 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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
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.
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
38 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
41 #include <sys/types.h>
43 #include <machine/atomic.h>
44 #include <machine/cpufunc.h>
47 * The general mutex structure provides recursive shared and exclusive
48 * locks, downgrade, a non-blocking upgrade, and various other functions.
50 * The structure is 16-byte aligned and either 16 or 32 bytes, designed
51 * for 32 or 64 bit cpus.
56 struct mtx_link *next;
57 struct mtx_link *prev;
62 typedef struct mtx_link *mtx_link_t;
65 volatile u_int mtx_lock;
67 struct thread *mtx_owner;
71 typedef struct mtx *mtx_t;
73 #define MTX_INITIALIZER { .mtx_lock = 0, .mtx_refs = 0, \
74 .mtx_owner = NULL, .mtx_link = NULL }
76 #define MTX_EXCLUSIVE 0x80000000
77 #define MTX_SHWANTED 0x40000000
78 #define MTX_EXWANTED 0x20000000
79 #define MTX_EXLINK 0x10000000
80 #define MTX_MASK 0x0FFFFFFF
82 #define MTX_PCATCH 0x00000001
84 #define MTX_OWNER_NONE NULL
85 #define MTX_OWNER_ANON ((struct thread *)-2)
87 #define MTX_LINK_IDLE 0
88 #define MTX_LINK_ABORTED -1
89 #define MTX_LINK_LINKED 1
90 #define MTX_LINK_ACQUIRED 2
95 * See also sys/mutex2.h
99 int _mtx_lock_ex_link(mtx_t mtx, mtx_link_t link, const char *ident, int flags, int to);
100 int _mtx_lock_ex(mtx_t mtx, const char *ident, int flags, int to);
101 int _mtx_lock_sh(mtx_t mtx, const char *ident, int flags, int to);
102 int _mtx_lock_ex_quick(mtx_t mtx, const char *ident);
103 int _mtx_lock_sh_quick(mtx_t mtx, const char *ident);
104 void _mtx_spinlock(mtx_t mtx);
105 int _mtx_spinlock_try(mtx_t mtx);
106 int _mtx_lock_ex_try(mtx_t mtx);
107 int _mtx_lock_sh_try(mtx_t mtx);
108 void _mtx_downgrade(mtx_t mtx);
109 int _mtx_upgrade_try(mtx_t mtx);
110 void _mtx_unlock(mtx_t mtx);
111 void mtx_abort_ex_link(mtx_t mtx, mtx_link_t link);