xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Low-level locking access to futex facilities. Stub version. |
| 2 | Copyright (C) 2014-2016 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 | <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 */ |