87 lines
3.5 KiB
C
87 lines
3.5 KiB
C
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/* Low-level locking access to futex facilities. Stub version.
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Copyright (C) 2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library. If not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _LOWLEVELLOCK_FUTEX_H
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#define _LOWLEVELLOCK_FUTEX_H 1
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#include <errno.h>
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/* Values for 'private' parameter of locking macros. Note pthreadP.h
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optimizes for these exact values, though they are not required. */
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#define LLL_PRIVATE 0
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#define LLL_SHARED 128
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/* For most of these macros, the return value is never really used.
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Nevertheless, the protocol is that each one returns a negated errno
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code for failure or zero for success. (Note that the corresponding
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Linux system calls can sometimes return positive values for success
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cases too. We never use those values.) */
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/* Wait while *FUTEXP == VAL for an lll_futex_wake call on FUTEXP. */
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#define lll_futex_wait(futexp, val, private) \
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lll_futex_timed_wait (futexp, val, NULL, private)
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/* Wait until a lll_futex_wake call on FUTEXP, or TIMEOUT elapses. */
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#define lll_futex_timed_wait(futexp, val, timeout, private) \
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-ENOSYS
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/* This macro should be defined only if FUTEX_CLOCK_REALTIME is also defined.
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If CLOCKBIT is zero, this is identical to lll_futex_timed_wait.
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If CLOCKBIT has FUTEX_CLOCK_REALTIME set, then it's the same but
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TIMEOUT is counted by CLOCK_REALTIME rather than CLOCK_MONOTONIC. */
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#define lll_futex_timed_wait_bitset(futexp, val, timeout, clockbit, private) \
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-ENOSYS
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/* Wake up up to NR waiters on FUTEXP. */
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#define lll_futex_wake(futexp, nr, private) \
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-ENOSYS
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/* Wake up up to NR_WAKE waiters on FUTEXP. Move up to NR_MOVE of the
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rest from waiting on FUTEXP to waiting on MUTEX (a different futex). */
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#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
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-ENOSYS
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/* Wake up up to NR_WAKE waiters on FUTEXP and NR_WAKE2 on FUTEXP2. */
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#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
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-ENOSYS
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/* Like lll_futex_wait (FUTEXP, VAL, PRIVATE) but with the expectation
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that lll_futex_cmp_requeue_pi (FUTEXP, _, _, MUTEX, _, PRIVATE) will
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be used to do the wakeup. Confers priority-inheritance behavior on
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the waiter. */
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#define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \
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lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private)
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/* Like lll_futex_wait_requeue_pi, but with a timeout. */
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#define lll_futex_timed_wait_requeue_pi(futexp, val, timeout, clockbit, \
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mutex, private) \
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-ENOSYS
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/* Like lll_futex_requeue, but pairs with lll_futex_wait_requeue_pi
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and inherits priority from the waiter. */
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#define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, \
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val, private) \
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-ENOSYS
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#endif /* lowlevellock-futex.h */
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