1 /*-
2 * Copyright (c) 2005 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 */
27
28 #ifndef _THR_DFLY_UMTX_H_
29 #define _THR_DFLY_UMTX_H_
30
31 #include <unistd.h>
32
33 #define cpu_pause() __asm __volatile("pause":::"memory")
34
35 typedef int umtx_t;
36
37 int __thr_umtx_lock(volatile umtx_t *mtx, int id, int timo);
38 int __thr_umtx_timedlock(volatile umtx_t *mtx, int id,
39 const struct timespec *timeout);
40 void __thr_umtx_unlock(volatile umtx_t *mtx, int v, int id);
41
42 static inline void
_thr_umtx_init(volatile umtx_t * mtx)43 _thr_umtx_init(volatile umtx_t *mtx)
44 {
45 *mtx = 0;
46 }
47
48 static inline int
_thr_umtx_trylock(volatile umtx_t * mtx,int id,int temporary)49 _thr_umtx_trylock(volatile umtx_t *mtx, int id, int temporary)
50 {
51 if (temporary)
52 sigblockall();
53 if (atomic_cmpset_acq_int(mtx, 0, id))
54 return (0);
55 cpu_pause();
56 if (atomic_cmpset_acq_int(mtx, 0, id))
57 return (0);
58 cpu_pause();
59 if (atomic_cmpset_acq_int(mtx, 0, id))
60 return (0);
61 if (temporary)
62 sigunblockall();
63 return (EBUSY);
64 }
65
66 static inline int
_thr_umtx_lock(volatile umtx_t * mtx,int id,int temporary)67 _thr_umtx_lock(volatile umtx_t *mtx, int id, int temporary)
68 {
69 int res;
70
71 if (temporary)
72 sigblockall();
73 if (atomic_cmpset_acq_int(mtx, 0, id))
74 return (0);
75 res = __thr_umtx_lock(mtx, id, 0);
76 if (res && temporary)
77 sigunblockall();
78 return res;
79 }
80
81 static inline int
_thr_umtx_timedlock(volatile umtx_t * mtx,int id,const struct timespec * timeout,int temporary)82 _thr_umtx_timedlock(volatile umtx_t *mtx, int id,
83 const struct timespec *timeout, int temporary)
84 {
85 int res;
86
87 if (temporary)
88 sigblockall();
89 if (atomic_cmpset_acq_int(mtx, 0, id)) {
90 return (0);
91 }
92 res = __thr_umtx_timedlock(mtx, id, timeout);
93 if (res && temporary)
94 sigunblockall();
95 return res;
96 }
97
98 static inline void
_thr_umtx_unlock(volatile umtx_t * mtx,int id,int temporary)99 _thr_umtx_unlock(volatile umtx_t *mtx, int id, int temporary)
100 {
101 int v;
102
103 v = atomic_swap_int(mtx, 0);
104 if (v != id)
105 __thr_umtx_unlock(mtx, v, id);
106 if (temporary)
107 sigunblockall();
108 }
109
110 int _thr_umtx_wait(volatile umtx_t *mtx, umtx_t exp,
111 const struct timespec *timeout, int clockid);
112 int _thr_umtx_wait_intr(volatile umtx_t *mtx, umtx_t exp);
113 void _thr_umtx_wake(volatile umtx_t *mtx, int count);
114 #endif
115