1 /* Copyright (C) 2005-2020 Free Software Foundation, Inc. 2 Contributed by Sebastian Huber <sebastian.huber@embedded-brains.de>. 3 4 This file is part of the GNU OpenMP Library (libgomp). 5 6 Libgomp is free software; you can redistribute it and/or modify it 7 under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 3, or (at your option) 9 any later version. 10 11 Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY 12 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 13 FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 more details. 15 16 Under Section 7 of GPL version 3, you are granted additional 17 permissions described in the GCC Runtime Library Exception, version 18 3.1, as published by the Free Software Foundation. 19 20 You should have received a copy of the GNU General Public License and 21 a copy of the GCC Runtime Library Exception along with this program; 22 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 <http://www.gnu.org/licenses/>. */ 24 25 /* This is the RTEMS implementation of a barrier synchronization 26 mechanism for libgomp. It is identical to the Linux implementation, except 27 that the futex API is slightly different. This type is private to the 28 library. */ 29 30 #include "libgomp.h" 31 #include "bar.h" 32 #include <limits.h> 33 34 static gomp_barrier_t * 35 generation_to_barrier (int *addr) 36 { 37 return (gomp_barrier_t *) 38 ((char *) addr - __builtin_offsetof (gomp_barrier_t, generation)); 39 } 40 41 static void 42 futex_wait (int *addr, int val) 43 { 44 gomp_barrier_t *bar = generation_to_barrier (addr); 45 _Futex_Wait (&bar->futex, addr, val); 46 } 47 48 static void 49 futex_wake (int *addr, int count) 50 { 51 gomp_barrier_t *bar = generation_to_barrier (addr); 52 _Futex_Wake (&bar->futex, count); 53 } 54 55 static int 56 do_spin (int *addr, int val) 57 { 58 unsigned long long i, count = gomp_spin_count_var; 59 60 if (__builtin_expect (gomp_managed_threads > gomp_available_cpus, 0)) 61 count = gomp_throttled_spin_count_var; 62 for (i = 0; i < count; i++) 63 if (__builtin_expect (__atomic_load_n (addr, MEMMODEL_RELAXED) != val, 0)) 64 return 0; 65 return 1; 66 } 67 68 static void 69 do_wait (int *addr, int val) 70 { 71 if (do_spin (addr, val)) 72 futex_wait (addr, val); 73 } 74 75 #define GOMP_WAIT_H 1 76 #include "../linux/bar.c" 77