libgomp/single.c

   1 /* Copyright (C) 2005 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 Lesser General Public License as published by
   8    the Free Software Foundation; either version 2.1 of the License, or
   9    (at your option) 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 Lesser General Public License for
  14    more details.
  15
  16    You should have received a copy of the GNU Lesser General Public License
  17    along with libgomp; see the file COPYING.LIB.  If not, write to the
  18    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  19    MA 02110-1301, USA.  */
  20
  21 /* As a special exception, if you link this library with other files, some
  22    of which are compiled with GCC, to produce an executable, this library
  23    does not by itself cause the resulting executable to be covered by the
  24    GNU General Public License.  This exception does not however invalidate
  25    any other reasons why the executable file might be covered by the GNU
  26    General Public License.  */
  27
  28 /* This file handles the SINGLE construct.  */
  29
  30 #include "libgomp.h"
  31
  32
  33 /* This routine is called when first encountering a SINGLE construct that
  34    doesn't have a COPYPRIVATE clause.  Returns true if this is the thread
  35    that should execute the clause.  */
  36
  37 bool
  38 GOMP_single_start (void)
  39 {
  40   bool ret = gomp_work_share_start (false);
  41   gomp_mutex_unlock (&gomp_thread ()->ts.work_share->lock);
  42   gomp_work_share_end_nowait ();
  43   return ret;
  44 }
  45
  46 /* This routine is called when first encountering a SINGLE construct that
  47    does have a COPYPRIVATE clause.  Returns NULL if this is the thread
  48    that should execute the clause; otherwise the return value is pointer
  49    given to GOMP_single_copy_end by the thread that did execute the clause.  */
  50
  51 void *
  52 GOMP_single_copy_start (void)
  53 {
  54   struct gomp_thread *thr = gomp_thread ();
  55
  56   bool first;
  57   void *ret;
  58
  59   first = gomp_work_share_start (false);
  60   gomp_mutex_unlock (&thr->ts.work_share->lock);
  61
  62   if (first)
  63     ret = NULL;
  64   else
  65     {
  66       gomp_barrier_wait (&thr->ts.team->barrier);
  67
  68       ret = thr->ts.work_share->copyprivate;
  69       gomp_work_share_end_nowait ();
  70     }
  71
  72   return ret;
  73 }
  74
  75 /* This routine is called when the thread that entered a SINGLE construct
  76    with a COPYPRIVATE clause gets to the end of the construct.  */
  77
  78 void
  79 GOMP_single_copy_end (void *data)
  80 {
  81   struct gomp_thread *thr = gomp_thread ();
  82   struct gomp_team *team = thr->ts.team;
  83
  84   if (team != NULL)
  85     {
  86       thr->ts.work_share->copyprivate = data;
  87       gomp_barrier_wait (&team->barrier);
  88     }
  89
  90   gomp_work_share_end_nowait ();
  91 }