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/* low level locking for pthread library. Generic futex-using version.
Copyright (C) 2003-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
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
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <futex-internal.h>
#include <atomic.h>
#include <stap-probe.h>
void
__lll_lock_wait_private (int *futex)
{
if (atomic_load_relaxed (futex) == 2)
goto futex;
while (atomic_exchange_acquire (futex, 2) != 0)
{
futex:
LIBC_PROBE (lll_lock_wait_private, 1, futex);
futex_wait ((unsigned int *) futex, 2, LLL_PRIVATE); /* Wait if *futex == 2. */
}
}
/* This function doesn't get included in libc. */
#if IS_IN (libpthread)
void
__lll_lock_wait (int *futex, int private)
{
if (atomic_load_relaxed (futex) == 2)
goto futex;
while (atomic_exchange_acquire (futex, 2) != 0)
{
futex:
LIBC_PROBE (lll_lock_wait, 1, futex);
futex_wait ((unsigned int *) futex, 2, private); /* Wait if *futex == 2. */
}
}
#endif
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