1 /* Copyright (C) 2005, 2008, 2009 Free Software Foundation, Inc. 2 Contributed by Richard Henderson <rth@redhat.com>. 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 file handles the SINGLE construct. */ 26 27 #include "libgomp.h" 28 29 30 /* This routine is called when first encountering a SINGLE construct that 31 doesn't have a COPYPRIVATE clause. Returns true if this is the thread 32 that should execute the clause. */ 33 34 bool 35 GOMP_single_start (void) 36 { 37 #ifdef HAVE_SYNC_BUILTINS 38 struct gomp_thread *thr = gomp_thread (); 39 struct gomp_team *team = thr->ts.team; 40 unsigned long single_count; 41 42 if (__builtin_expect (team == NULL, 0)) 43 return true; 44 45 single_count = thr->ts.single_count++; 46 return __sync_bool_compare_and_swap (&team->single_count, single_count, 47 single_count + 1L); 48 #else 49 bool ret = gomp_work_share_start (false); 50 if (ret) 51 gomp_work_share_init_done (); 52 gomp_work_share_end_nowait (); 53 return ret; 54 #endif 55 } 56 57 /* This routine is called when first encountering a SINGLE construct that 58 does have a COPYPRIVATE clause. Returns NULL if this is the thread 59 that should execute the clause; otherwise the return value is pointer 60 given to GOMP_single_copy_end by the thread that did execute the clause. */ 61 62 void * 63 GOMP_single_copy_start (void) 64 { 65 struct gomp_thread *thr = gomp_thread (); 66 67 bool first; 68 void *ret; 69 70 first = gomp_work_share_start (false); 71 72 if (first) 73 { 74 gomp_work_share_init_done (); 75 ret = NULL; 76 } 77 else 78 { 79 gomp_team_barrier_wait (&thr->ts.team->barrier); 80 81 ret = thr->ts.work_share->copyprivate; 82 gomp_work_share_end_nowait (); 83 } 84 85 return ret; 86 } 87 88 /* This routine is called when the thread that entered a SINGLE construct 89 with a COPYPRIVATE clause gets to the end of the construct. */ 90 91 void 92 GOMP_single_copy_end (void *data) 93 { 94 struct gomp_thread *thr = gomp_thread (); 95 struct gomp_team *team = thr->ts.team; 96 97 if (team != NULL) 98 { 99 thr->ts.work_share->copyprivate = data; 100 gomp_team_barrier_wait (&team->barrier); 101 } 102 103 gomp_work_share_end_nowait (); 104 } 105