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fb4cc8a0 | 1 | /* Low-level lock implementation. Mach gsync-based version. |
6d7e8eda | 2 | Copyright (C) 1994-2023 Free Software Foundation, Inc. |
fb4cc8a0 AA |
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 | |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
fb4cc8a0 AA |
18 | |
19 | #ifndef _MACH_LOWLEVELLOCK_H | |
20 | #define _MACH_LOWLEVELLOCK_H 1 | |
21 | ||
22 | #include <mach/gnumach.h> | |
23 | #include <atomic.h> | |
24 | ||
25 | /* Gsync flags. */ | |
26 | #ifndef GSYNC_SHARED | |
79962d89 ST |
27 | # define GSYNC_SHARED 0x01 |
28 | # define GSYNC_QUAD 0x02 | |
29 | # define GSYNC_TIMED 0x04 | |
30 | # define GSYNC_BROADCAST 0x08 | |
31 | # define GSYNC_MUTATE 0x10 | |
fb4cc8a0 AA |
32 | #endif |
33 | ||
34 | /* Static initializer for low-level locks. */ | |
18c2ab9a | 35 | #define LLL_LOCK_INITIALIZER 0 |
fb4cc8a0 | 36 | |
644d98ec | 37 | #define LLL_PRIVATE 0 |
33038a7d | 38 | #define LLL_SHARED GSYNC_SHARED |
644d98ec | 39 | |
59bb023c ST |
40 | /* Interruptible version of __gsync_wait. */ |
41 | extern kern_return_t __gsync_wait_intr | |
42 | ( | |
43 | mach_port_t task, | |
44 | vm_offset_t addr, | |
45 | unsigned val1, | |
46 | unsigned val2, | |
47 | natural_t msec, | |
48 | int flags | |
49 | ); | |
50 | ||
fb4cc8a0 AA |
51 | /* Wait on address PTR, without blocking if its contents |
52 | * are different from VAL. */ | |
bec41242 | 53 | #define __lll_wait(ptr, val, flags) \ |
fb4cc8a0 AA |
54 | __gsync_wait (__mach_task_self (), \ |
55 | (vm_offset_t)(ptr), (val), 0, 0, (flags)) | |
bec41242 ST |
56 | #define lll_wait(var, val, flags) \ |
57 | __lll_wait (&(var), val, flags) | |
fb4cc8a0 | 58 | |
59bb023c ST |
59 | /* Interruptible version. */ |
60 | #define __lll_wait_intr(ptr, val, flags) \ | |
61 | __gsync_wait_intr (__mach_task_self (), \ | |
62 | (vm_offset_t)(ptr), (val), 0, 0, (flags)) | |
63 | #define lll_wait_intr(var, val, flags) \ | |
64 | __lll_wait_intr ((&var), val, flags) | |
65 | ||
fb4cc8a0 | 66 | /* Wake one or more threads waiting on address PTR. */ |
bec41242 | 67 | #define __lll_wake(ptr, flags) \ |
fb4cc8a0 | 68 | __gsync_wake (__mach_task_self (), (vm_offset_t)(ptr), 0, (flags)) |
bec41242 ST |
69 | #define lll_wake(var, flags) \ |
70 | __lll_wake (&(var), flags) | |
fb4cc8a0 AA |
71 | |
72 | /* Acquire the lock at PTR. */ | |
bec41242 | 73 | #define __lll_lock(ptr, flags) \ |
fb4cc8a0 AA |
74 | ({ \ |
75 | int *__iptr = (int *)(ptr); \ | |
76 | int __flags = (flags); \ | |
34a5a146 JM |
77 | if (*__iptr != 0 \ |
78 | || atomic_compare_and_exchange_bool_acq (__iptr, 1, 0) != 0) \ | |
fb4cc8a0 AA |
79 | while (1) \ |
80 | { \ | |
22f4ab2d | 81 | if (atomic_exchange_acquire (__iptr, 2) == 0) \ |
fb4cc8a0 | 82 | break; \ |
bec41242 | 83 | __lll_wait (__iptr, 2, __flags); \ |
fb4cc8a0 AA |
84 | } \ |
85 | (void)0; \ | |
86 | }) | |
bec41242 ST |
87 | #define lll_lock(var, flags) \ |
88 | __lll_lock (&(var), flags) | |
fb4cc8a0 AA |
89 | |
90 | /* Try to acquire the lock at PTR, without blocking. | |
91 | Evaluates to zero on success. */ | |
bec41242 | 92 | #define __lll_trylock(ptr) \ |
fb4cc8a0 AA |
93 | ({ \ |
94 | int *__iptr = (int *)(ptr); \ | |
34a5a146 JM |
95 | *__iptr == 0 \ |
96 | && atomic_compare_and_exchange_bool_acq (__iptr, 1, 0) == 0 ? 0 : -1; \ | |
fb4cc8a0 | 97 | }) |
bec41242 ST |
98 | #define lll_trylock(var) \ |
99 | __lll_trylock (&(var)) | |
fb4cc8a0 AA |
100 | |
101 | /* Release the lock at PTR. */ | |
bec41242 | 102 | #define __lll_unlock(ptr, flags) \ |
fb4cc8a0 AA |
103 | ({ \ |
104 | int *__iptr = (int *)(ptr); \ | |
22f4ab2d | 105 | if (atomic_exchange_release (__iptr, 0) == 2) \ |
bec41242 | 106 | __lll_wake (__iptr, (flags)); \ |
fb4cc8a0 AA |
107 | (void)0; \ |
108 | }) | |
bec41242 ST |
109 | #define lll_unlock(var, flags) \ |
110 | __lll_unlock (&(var), flags) | |
fb4cc8a0 AA |
111 | |
112 | #endif |