54 lines
1.7 KiB
C
54 lines
1.7 KiB
C
/* 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. */
|
|
while (atomic_exchange_acq (futex, 2) != 0)
|
|
{
|
|
/* If *futex == 2, wait until woken or timeout. */
|
|
int err = __nacl_irt_futex.futex_wait_abs ((volatile int *) futex, 2,
|
|
abstime);
|
|
if (err != 0)
|
|
{
|
|
if (__glibc_likely (err == ETIMEDOUT))
|
|
return err;
|
|
assert (err == EAGAIN);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|