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Diffstat (limited to 'REORG.TODO/sysdeps/unix/sysv/linux/lowlevellock-futex.h')
| -rw-r--r-- | REORG.TODO/sysdeps/unix/sysv/linux/lowlevellock-futex.h | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/unix/sysv/linux/lowlevellock-futex.h b/REORG.TODO/sysdeps/unix/sysv/linux/lowlevellock-futex.h new file mode 100644 index 0000000000..bb4fbae13b --- /dev/null +++ b/REORG.TODO/sysdeps/unix/sysv/linux/lowlevellock-futex.h @@ -0,0 +1,145 @@ +/* Low-level locking access to futex facilities. Linux version. + Copyright (C) 2005-2017 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 */ |