/* low level locking for pthread library. Generic futex-using version. Copyright (C) 2003-2019 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