| /* Copyright (C) 2008, 2009, 2011 Free Software Foundation, Inc. |
| Contributed by Jakub Jelinek <jakub@redhat.com>. |
| |
| This file is part of the GNU OpenMP Library (libgomp). |
| |
| Libgomp is free software; you can redistribute it and/or modify it |
| under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3, or (at your option) |
| any later version. |
| |
| Libgomp 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 General Public License for |
| more details. |
| |
| Under Section 7 of GPL version 3, you are granted additional |
| permissions described in the GCC Runtime Library Exception, version |
| 3.1, as published by the Free Software Foundation. |
| |
| You should have received a copy of the GNU General Public License and |
| a copy of the GCC Runtime Library Exception along with this program; |
| see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* This is a Linux specific implementation of a mutex synchronization |
| mechanism for libgomp. This type is private to the library. This |
| implementation uses atomic instructions and the futex syscall. */ |
| |
| #ifndef GOMP_WAIT_H |
| #define GOMP_WAIT_H 1 |
| |
| #include "libgomp.h" |
| #include <errno.h> |
| |
| #ifdef HAVE_ATTRIBUTE_VISIBILITY |
| # pragma GCC visibility push(hidden) |
| #endif |
| #include "libgomp_futex.h" |
| |
| static inline void do_wait (int *addr, int val) |
| { |
| unsigned long long i, count = gomp_spin_count_var; |
| |
| if (__builtin_expect (gomp_managed_threads > gomp_available_cpus, 0)) |
| count = gomp_throttled_spin_count_var; |
| for (i = 0; i < count; i++) |
| if (__builtin_expect (*addr != val, 0)) |
| return; |
| else |
| cpu_relax (); |
| futex_wait (addr, val); |
| } |
| |
| #ifdef HAVE_ATTRIBUTE_VISIBILITY |
| # pragma GCC visibility pop |
| #endif |
| |
| #endif /* GOMP_WAIT_H */ |
