1 /* Low-level lock implementation. High-level Hurd helpers.
2 Copyright (C) 1999-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #ifndef _HURD_LOCK_H
20 #define _HURD_LOCK_H 1
21
22 #include <mach/lowlevellock.h>
23
24 struct timespec;
25
26 /* Flags for robust locks. */
27 #define LLL_WAITERS (1U << 31)
28 #define LLL_DEAD_OWNER (1U << 30)
29
30 #define LLL_OWNER_MASK ~(LLL_WAITERS | LLL_DEAD_OWNER)
31
32 /* Wait on 64-bit address PTR, without blocking if its contents
33 are different from the pair <LO, HI>. */
34 #define __lll_xwait(ptr, lo, hi, flags) \
35 __gsync_wait (__mach_task_self (), \
36 (vm_offset_t)ptr, lo, hi, 0, flags | GSYNC_QUAD)
37
38 /* Same as '__lll_wait', but only block for MLSEC milliseconds. */
39 #define __lll_timed_wait(ptr, val, mlsec, flags) \
40 __gsync_wait (__mach_task_self (), \
41 (vm_offset_t)ptr, val, 0, mlsec, flags | GSYNC_TIMED)
42
43 /* Interruptible version. */
44 #define __lll_timed_wait_intr(ptr, val, mlsec, flags) \
45 __gsync_wait_intr (__mach_task_self (), \
46 (vm_offset_t)ptr, val, 0, mlsec, flags | GSYNC_TIMED)
47
48 /* Same as '__lll_xwait', but only block for MLSEC milliseconds. */
49 #define __lll_timed_xwait(ptr, lo, hi, mlsec, flags) \
50 __gsync_wait (__mach_task_self (), (vm_offset_t)ptr, \
51 lo, hi, mlsec, flags | GSYNC_TIMED | GSYNC_QUAD)
52
53 /* Same as '__lll_wait', but only block until TSP elapses,
54 using clock CLK. */
55 extern int __lll_abstimed_wait (void *__ptr, int __val,
56 const struct timespec *__tsp, int __flags, int __clk);
57
58 /* Interruptible version. */
59 extern int __lll_abstimed_wait_intr (void *__ptr, int __val,
60 const struct timespec *__tsp, int __flags, int __clk);
61
62 /* Same as 'lll_xwait', but only block until TSP elapses,
63 using clock CLK. */
64 extern int __lll_abstimed_xwait (void *__ptr, int __lo, int __hi,
65 const struct timespec *__tsp, int __flags, int __clk);
66
67 /* Same as 'lll_lock', but return with an error if TSP elapses,
68 using clock CLK. */
69 extern int __lll_abstimed_lock (void *__ptr,
70 const struct timespec *__tsp, int __flags, int __clk);
71
72 /* Acquire the lock at PTR, but return with an error if
73 the process containing the owner thread dies. */
74 extern int __lll_robust_lock (void *__ptr, int __flags);
75 #define lll_robust_lock(var, flags) \
76 __lll_robust_lock (&(var), flags)
77
78 /* Same as '__lll_robust_lock', but only block until TSP
79 elapses, using clock CLK. */
80 extern int __lll_robust_abstimed_lock (void *__ptr,
81 const struct timespec *__tsp, int __flags, int __clk);
82
83 /* Same as '__lll_robust_lock', but return with an error
84 if the lock cannot be acquired without blocking. */
85 extern int __lll_robust_trylock (void *__ptr);
86 #define lll_robust_trylock(var) \
87 __lll_robust_trylock (&(var))
88
89 /* Wake one or more threads waiting on address PTR,
90 setting its value to VAL before doing so. */
91 #define __lll_set_wake(ptr, val, flags) \
92 __gsync_wake (__mach_task_self (), \
93 (vm_offset_t)ptr, val, flags | GSYNC_MUTATE)
94
95 /* Release the robust lock at PTR. */
96 extern void __lll_robust_unlock (void *__ptr, int __flags);
97 #define lll_robust_unlock(var, flags) \
98 __lll_robust_unlock (&(var), flags)
99
100 /* Rearrange threads waiting on address SRC to instead wait on
101 DST, waking one of them if WAIT_ONE is non-zero. */
102 #define __lll_requeue(src, dst, wake_one, flags) \
103 __gsync_requeue (__mach_task_self (), (vm_offset_t)src, \
104 (vm_offset_t)dst, (boolean_t)wake_one, flags)
105
106 /* The following are hacks that allow us to simulate optional
107 parameters in C, to avoid having to pass the clock id for
108 every one of these calls, defaulting to CLOCK_REALTIME if
109 no argument is passed. */
110
111 #define lll_abstimed_wait(var, val, tsp, flags, ...) \
112 ({ \
113 const clockid_t __clk[] = { CLOCK_REALTIME, ##__VA_ARGS__ }; \
114 __lll_abstimed_wait (&(var), (val), (tsp), (flags), \
115 __clk[sizeof (__clk) / sizeof (__clk[0]) - 1]); \
116 })
117
118 #define lll_abstimed_wait_intr(var, val, tsp, flags, ...) \
119 ({ \
120 const clockid_t __clk[] = { CLOCK_REALTIME, ##__VA_ARGS__ }; \
121 __lll_abstimed_wait_intr (&(var), (val), (tsp), (flags), \
122 __clk[sizeof (__clk) / sizeof (__clk[0]) - 1]); \
123 })
124
125 #define lll_abstimed_xwait(var, lo, hi, tsp, flags, ...) \
126 ({ \
127 const clockid_t __clk[] = { CLOCK_REALTIME, ##__VA_ARGS__ }; \
128 __lll_abstimed_xwait (&(var), (lo), (hi), (tsp), (flags), \
129 __clk[sizeof (__clk) / sizeof (__clk[0]) - 1]); \
130 })
131
132 #define lll_abstimed_lock(var, tsp, flags, ...) \
133 ({ \
134 const clockid_t __clk[] = { CLOCK_REALTIME, ##__VA_ARGS__ }; \
135 __lll_abstimed_lock (&(var), (tsp), (flags), \
136 __clk[sizeof (__clk) / sizeof (__clk[0]) - 1]); \
137 })
138
139 #define lll_robust_abstimed_lock(var, tsp, flags, ...) \
140 ({ \
141 const clockid_t __clk[] = { CLOCK_REALTIME, ##__VA_ARGS__ }; \
142 __lll_robust_abstimed_lock (&(var), (tsp), (flags), \
143 __clk[sizeof (__clk) / sizeof (__clk[0]) - 1]); \
144 })
145
146
147 #endif