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NaCl: Add NaCl-specific __lll_timedlock_wait.

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Roland McGrath 2015-05-26 15:30:47 -07:00
parent 68c97aef62
commit 1f3a37b19c
2 changed files with 54 additions and 0 deletions
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2015-05-26 Roland McGrath <roland@hack.frob.com>
* sysdeps/nacl/lll_timedlock_wait.c: New file.
* nptl/lowlevellock.c (__lll_timedlock_wait): Moved ...
* nptl/lll_timedlock_wait.c: ... to this new file.
* nptl/Makefile (libpthread-routines): Add it.

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sysdeps/nacl/lll_timedlock_wait.c Normal file
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/* Timed low level locking for pthread library. NaCl version.
Copyright (C) 2015 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/>. */
#include <assert.h>
#include <atomic.h>
#include <errno.h>
#include <lowlevellock.h>
#include <sys/time.h>
/* This behaves the same as the generic version in nptl/. It's simpler
because it doesn't need to convert an absolute timeout to a relative
one (and back again in the lll_futex_timed_wait macro). */
int
__lll_timedlock_wait (int *futex, const struct timespec *abstime, int private)
{
/* Reject invalid timeouts. */
if (__glibc_unlikely (abstime->tv_nsec < 0)
|| __glibc_unlikely (abstime->tv_nsec >= 1000000000))
return EINVAL;
/* Try locking. */
int result = 0;
while (atomic_exchange_acq (futex, 2) != 0)
{
/* If *futex == 2, wait until woken or timeout. */
result = __nacl_irt_futex.futex_wait_abs ((volatile int *) futex, 2,
abstime);
if (__glibc_likely (result == 0)
|| __glibc_likely (result == ETIMEDOUT))
break;
assert (result == EAGAIN);
}
return result;
}