]>
Commit | Line | Data |
---|---|---|
3df6f22e | 1 | /* Low-level locking access to futex facilities. Stub version. |
04277e02 | 2 | Copyright (C) 2014-2019 Free Software Foundation, Inc. |
3df6f22e RM |
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 | <http://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #ifndef _LOWLEVELLOCK_FUTEX_H | |
20 | #define _LOWLEVELLOCK_FUTEX_H 1 | |
21 | ||
22 | #include <errno.h> | |
23 | ||
24 | ||
25 | /* Values for 'private' parameter of locking macros. Note pthreadP.h | |
26 | optimizes for these exact values, though they are not required. */ | |
27 | #define LLL_PRIVATE 0 | |
28 | #define LLL_SHARED 128 | |
29 | ||
30 | ||
31 | /* For most of these macros, the return value is never really used. | |
32 | Nevertheless, the protocol is that each one returns a negated errno | |
33 | code for failure or zero for success. (Note that the corresponding | |
34 | Linux system calls can sometimes return positive values for success | |
35 | cases too. We never use those values.) */ | |
36 | ||
37 | ||
38 | /* Wait while *FUTEXP == VAL for an lll_futex_wake call on FUTEXP. */ | |
39 | #define lll_futex_wait(futexp, val, private) \ | |
40 | lll_futex_timed_wait (futexp, val, NULL, private) | |
41 | ||
42 | /* Wait until a lll_futex_wake call on FUTEXP, or TIMEOUT elapses. */ | |
43 | #define lll_futex_timed_wait(futexp, val, timeout, private) \ | |
44 | -ENOSYS | |
45 | ||
46 | /* This macro should be defined only if FUTEX_CLOCK_REALTIME is also defined. | |
47 | If CLOCKBIT is zero, this is identical to lll_futex_timed_wait. | |
48 | If CLOCKBIT has FUTEX_CLOCK_REALTIME set, then it's the same but | |
49 | TIMEOUT is counted by CLOCK_REALTIME rather than CLOCK_MONOTONIC. */ | |
50 | #define lll_futex_timed_wait_bitset(futexp, val, timeout, clockbit, private) \ | |
51 | -ENOSYS | |
52 | ||
53 | /* Wake up up to NR waiters on FUTEXP. */ | |
54 | #define lll_futex_wake(futexp, nr, private) \ | |
55 | -ENOSYS | |
56 | ||
57 | /* Wake up up to NR_WAKE waiters on FUTEXP. Move up to NR_MOVE of the | |
58 | rest from waiting on FUTEXP to waiting on MUTEX (a different futex). */ | |
59 | #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \ | |
60 | -ENOSYS | |
61 | ||
62 | /* Wake up up to NR_WAKE waiters on FUTEXP and NR_WAKE2 on FUTEXP2. */ | |
63 | #define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \ | |
64 | -ENOSYS | |
65 | ||
66 | ||
67 | /* Like lll_futex_wait (FUTEXP, VAL, PRIVATE) but with the expectation | |
68 | that lll_futex_cmp_requeue_pi (FUTEXP, _, _, MUTEX, _, PRIVATE) will | |
69 | be used to do the wakeup. Confers priority-inheritance behavior on | |
70 | the waiter. */ | |
71 | #define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \ | |
72 | lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private) | |
73 | ||
74 | /* Like lll_futex_wait_requeue_pi, but with a timeout. */ | |
75 | #define lll_futex_timed_wait_requeue_pi(futexp, val, timeout, clockbit, \ | |
76 | mutex, private) \ | |
77 | -ENOSYS | |
78 | ||
79 | /* Like lll_futex_requeue, but pairs with lll_futex_wait_requeue_pi | |
80 | and inherits priority from the waiter. */ | |
81 | #define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, \ | |
82 | val, private) \ | |
83 | -ENOSYS | |
84 | ||
85 | ||
86 | #endif /* lowlevellock-futex.h */ |