88 lines
4.1 KiB
C
88 lines
4.1 KiB
C
/* Low-level locking access to futex facilities. NaCl version.
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Copyright (C) 2015 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 <nacl-interfaces.h>
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#include <time.h>
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#pragma GCC diagnostic ignored "-Wunused-value" /* XXX */
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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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#define FUTEX_PRIVATE_FLAG 0 /* XXX */
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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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(- __nacl_irt_futex.futex_wait_abs ((volatile int *) (futexp), val, NULL))
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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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({ \
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/* This timeout is relative, but the IRT call wants it absolute. */\
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const struct timespec *_to = (timeout); \
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struct timespec _ts; \
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int _err = 0; \
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if (_to != NULL \
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&& __glibc_likely ((_err = __nacl_irt_clock.clock_gettime \
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(CLOCK_REALTIME, &_ts)) == 0)) \
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{ \
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_ts.tv_sec += _to->tv_sec; \
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_ts.tv_nsec += _to->tv_nsec; \
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while (_ts.tv_nsec >= 1000000000) \
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{ \
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_ts.tv_nsec -= 1000000000; \
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++_ts.tv_sec; \
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} \
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_to = &_ts; \
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} \
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if (_err == 0) \
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_err = __nacl_irt_futex.futex_wait_abs \
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((volatile int *) (futexp), val, _to); \
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-_err; \
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})
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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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({ \
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int _woken; \
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- __nacl_irt_futex.futex_wake ((volatile int *) (futexp), nr, &_woken); \
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})
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/* NaCl does not support the requeue operation. The only use of this is in
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pthread_cond_broadcast, which handles an error return by falling back to
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plain lll_futex_wake. */
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#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
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((futexp), (nr_wake), (nr_move), (mutex), (val), (private), -ENOSYS)
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/* NaCl does not support the special wake-unlock operation. The only use
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of this is in pthread_cond_signal, which handles an error return by
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falling back to plain lll_futex_wake. */
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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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((futexp), (nr_wake), (nr_wake2), (futexp2), (private), -ENOSYS)
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#endif /* lowlevellock-futex.h */
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