1 /*
2 * Copyright © 2015 Intel
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24 #ifndef UTIL_FUTEX_H
25 #define UTIL_FUTEX_H
26
27 #if defined(HAVE_LINUX_FUTEX_H)
28 #define UTIL_FUTEX_SUPPORTED 1
29
30 #include <limits.h>
31 #include <stdint.h>
32 #include <unistd.h>
33 #include <linux/futex.h>
34 #include <sys/syscall.h>
35 #include <sys/time.h>
36
sys_futex(void * addr1,int op,int val1,const struct timespec * timeout,void * addr2,int val3)37 static inline long sys_futex(void *addr1, int op, int val1, const struct timespec *timeout, void *addr2, int val3)
38 {
39 return syscall(SYS_futex, addr1, op, val1, timeout, addr2, val3);
40 }
41
futex_wake(uint32_t * addr,int count)42 static inline int futex_wake(uint32_t *addr, int count)
43 {
44 return sys_futex(addr, FUTEX_WAKE, count, NULL, NULL, 0);
45 }
46
futex_wait(uint32_t * addr,int32_t value,const struct timespec * timeout)47 static inline int futex_wait(uint32_t *addr, int32_t value, const struct timespec *timeout)
48 {
49 /* FUTEX_WAIT_BITSET with FUTEX_BITSET_MATCH_ANY is equivalent to
50 * FUTEX_WAIT, except that it treats the timeout as absolute. */
51 return sys_futex(addr, FUTEX_WAIT_BITSET, value, timeout, NULL,
52 FUTEX_BITSET_MATCH_ANY);
53 }
54
55 #elif defined(__FreeBSD__)
56 #define UTIL_FUTEX_SUPPORTED 1
57
58 #include <assert.h>
59 #include <errno.h>
60 #include <fcntl.h>
61 #include <sys/types.h>
62 #include <sys/umtx.h>
63 #include <sys/time.h>
64
futex_wake(uint32_t * addr,int count)65 static inline int futex_wake(uint32_t *addr, int count)
66 {
67 assert(count == (int)(uint32_t)count); /* Check that bits weren't discarded */
68 return _umtx_op(addr, UMTX_OP_WAKE, (uint32_t)count, NULL, NULL) == -1 ? errno : 0;
69 }
70
futex_wait(uint32_t * addr,int32_t value,struct timespec * timeout)71 static inline int futex_wait(uint32_t *addr, int32_t value, struct timespec *timeout)
72 {
73 void *uaddr = NULL, *uaddr2 = NULL;
74 struct _umtx_time tmo = {
75 ._flags = UMTX_ABSTIME,
76 ._clockid = CLOCK_MONOTONIC
77 };
78
79 assert(value == (int)(uint32_t)value); /* Check that bits weren't discarded */
80
81 if (timeout != NULL) {
82 tmo._timeout = *timeout;
83 uaddr = (void *)(uintptr_t)sizeof(tmo);
84 uaddr2 = (void *)&tmo;
85 }
86
87 return _umtx_op(addr, UMTX_OP_WAIT_UINT, (uint32_t)value, uaddr, uaddr2) == -1 ? errno : 0;
88 }
89 #elif defined(__DragonFly__)
90 #define UTIL_FUTEX_SUPPORTED 1
91
92 #include <errno.h>
93 #include <unistd.h>
94 #include <time.h>
95
futex_wake(uint32_t * ptr,int count)96 static inline int futex_wake(uint32_t *ptr, int count)
97 {
98 return umtx_wakeup((volatile const int*)ptr, count);
99 }
100
futex_wait(uint32_t * ptr,int value,struct timespec * timeout)101 static inline int futex_wait(uint32_t *ptr, int value, struct timespec *timeout)
102 {
103 int timo = 0;
104 int ret;
105 if (timeout != NULL) {
106 timo = timeout->tv_sec * 1000*1000 + timeout->tv_nsec / 1000; /* XXX check overflow? */
107 if (timo < 0)
108 timo = 1 << 26; /* about 1 minute or so */ // 0x7fffffff; /* XXX ~35 minutes */
109 if (timo == 0 && timeout->tv_nsec > 0)
110 timo = 1; /* cap up to one 1us */
111 }
112 ret = umtx_sleep((volatile const int*)ptr, value, timo);
113 if (ret == 0)
114 return 0;
115 /* errno mangling for compat */
116 if (errno == EBUSY)
117 return EWOULDBLOCK;
118 if (errno == EWOULDBLOCK)
119 return ETIMEDOUT;
120 return errno;
121 }
122
123 #elif defined(__OpenBSD__)
124 #define UTIL_FUTEX_SUPPORTED 1
125
126 #include <sys/time.h>
127 #include <sys/futex.h>
128
futex_wake(uint32_t * addr,int count)129 static inline int futex_wake(uint32_t *addr, int count)
130 {
131 return futex(addr, FUTEX_WAKE, count, NULL, NULL);
132 }
133
futex_wait(uint32_t * addr,int32_t value,const struct timespec * timeout)134 static inline int futex_wait(uint32_t *addr, int32_t value, const struct timespec *timeout)
135 {
136 struct timespec tsnow, tsrel;
137
138 if (timeout == NULL)
139 return futex(addr, FUTEX_WAIT, value, NULL, NULL);
140
141 clock_gettime(CLOCK_MONOTONIC, &tsnow);
142 if (timespeccmp(&tsnow, timeout, <))
143 timespecsub(timeout, &tsnow, &tsrel);
144 else
145 timespecclear(&tsrel);
146 return futex(addr, FUTEX_WAIT, value, &tsrel, NULL);
147 }
148
149 #else
150 #define UTIL_FUTEX_SUPPORTED 0
151 #endif
152
153 #endif /* UTIL_FUTEX_H */
154