mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-26 23:10:06 +00:00
56 lines
1.7 KiB
C
56 lines
1.7 KiB
C
/* 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 <lowlevellock.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);
|
|
lll_futex_wait (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);
|
|
lll_futex_wait (futex, 2, private); /* Wait if *futex == 2. */
|
|
}
|
|
}
|
|
#endif
|