| /* Low-level locking access to futex facilities. Linux version. |
| Copyright (C) 2005-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #ifndef _LOWLEVELLOCK_FUTEX_H |
| #define _LOWLEVELLOCK_FUTEX_H 1 |
| |
| #ifndef __ASSEMBLER__ |
| #include <sysdep.h> |
| #include <tls.h> |
| #include <kernel-features.h> |
| #endif |
| |
| #define FUTEX_WAIT 0 |
| #define FUTEX_WAKE 1 |
| #define FUTEX_REQUEUE 3 |
| #define FUTEX_CMP_REQUEUE 4 |
| #define FUTEX_WAKE_OP 5 |
| #define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) | 1) |
| #define FUTEX_LOCK_PI 6 |
| #define FUTEX_UNLOCK_PI 7 |
| #define FUTEX_TRYLOCK_PI 8 |
| #define FUTEX_WAIT_BITSET 9 |
| #define FUTEX_WAKE_BITSET 10 |
| #define FUTEX_WAIT_REQUEUE_PI 11 |
| #define FUTEX_CMP_REQUEUE_PI 12 |
| #define FUTEX_PRIVATE_FLAG 128 |
| #define FUTEX_CLOCK_REALTIME 256 |
| |
| #define FUTEX_BITSET_MATCH_ANY 0xffffffff |
| |
| /* Values for 'private' parameter of locking macros. Yes, the |
| definition seems to be backwards. But it is not. The bit will be |
| reversed before passing to the system call. */ |
| #define LLL_PRIVATE 0 |
| #define LLL_SHARED FUTEX_PRIVATE_FLAG |
| |
| #ifndef __ASSEMBLER__ |
| |
| #if IS_IN (libc) || IS_IN (rtld) |
| /* In libc.so or ld.so all futexes are private. */ |
| # ifdef __ASSUME_PRIVATE_FUTEX |
| # define __lll_private_flag(fl, private) \ |
| ({ \ |
| /* Prevent warnings in callers of this macro. */ \ |
| int __lll_private_flag_priv __attribute__ ((unused)); \ |
| __lll_private_flag_priv = (private); \ |
| ((fl) | FUTEX_PRIVATE_FLAG); \ |
| }) |
| # else |
| # define __lll_private_flag(fl, private) \ |
| ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex)) |
| # endif |
| #else |
| # ifdef __ASSUME_PRIVATE_FUTEX |
| # define __lll_private_flag(fl, private) \ |
| (((fl) | FUTEX_PRIVATE_FLAG) ^ (private)) |
| # else |
| # define __lll_private_flag(fl, private) \ |
| (__builtin_constant_p (private) \ |
| ? ((private) == 0 \ |
| ? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex)) \ |
| : (fl)) \ |
| : ((fl) | (((private) ^ FUTEX_PRIVATE_FLAG) \ |
| & THREAD_GETMEM (THREAD_SELF, header.private_futex)))) |
| # endif |
| #endif |
| |
| #define lll_futex_syscall(nargs, futexp, op, ...) \ |
| ({ \ |
| INTERNAL_SYSCALL_DECL (__err); \ |
| long int __ret = INTERNAL_SYSCALL (futex, __err, nargs, futexp, op, \ |
| __VA_ARGS__); \ |
| (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (__ret, __err)) \ |
| ? -INTERNAL_SYSCALL_ERRNO (__ret, __err) : 0); \ |
| }) |
| |
| #define lll_futex_wait(futexp, val, private) \ |
| lll_futex_timed_wait (futexp, val, NULL, private) |
| |
| #define lll_futex_timed_wait(futexp, val, timeout, private) \ |
| lll_futex_syscall (4, futexp, \ |
| __lll_private_flag (FUTEX_WAIT, private), \ |
| val, timeout) |
| |
| #define lll_futex_timed_wait_bitset(futexp, val, timeout, clockbit, private) \ |
| lll_futex_syscall (6, futexp, \ |
| __lll_private_flag (FUTEX_WAIT_BITSET | (clockbit), \ |
| private), \ |
| val, timeout, NULL /* Unused. */, \ |
| FUTEX_BITSET_MATCH_ANY) |
| |
| #define lll_futex_wake(futexp, nr, private) \ |
| lll_futex_syscall (4, futexp, \ |
| __lll_private_flag (FUTEX_WAKE, private), nr, 0) |
| |
| /* Returns non-zero if error happened, zero if success. */ |
| #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \ |
| lll_futex_syscall (6, futexp, \ |
| __lll_private_flag (FUTEX_CMP_REQUEUE, private), \ |
| nr_wake, nr_move, mutex, val) |
| |
| /* Returns non-zero if error happened, zero if success. */ |
| #define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \ |
| lll_futex_syscall (6, futexp, \ |
| __lll_private_flag (FUTEX_WAKE_OP, private), \ |
| nr_wake, nr_wake2, futexp2, \ |
| FUTEX_OP_CLEAR_WAKE_IF_GT_ONE) |
| |
| /* Priority Inheritance support. */ |
| #define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \ |
| lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private) |
| |
| #define lll_futex_timed_wait_requeue_pi(futexp, val, timeout, clockbit, \ |
| mutex, private) \ |
| lll_futex_syscall (5, futexp, \ |
| __lll_private_flag (FUTEX_WAIT_REQUEUE_PI \ |
| | (clockbit), private), \ |
| val, timeout, mutex) |
| |
| |
| #define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, \ |
| val, private) \ |
| lll_futex_syscall (6, futexp, \ |
| __lll_private_flag (FUTEX_CMP_REQUEUE_PI, \ |
| private), \ |
| nr_wake, nr_move, mutex, val) |
| |
| #endif /* !__ASSEMBLER__ */ |
| |
| #endif /* lowlevellock-futex.h */ |