gcc/libgomp/single.c

105 lines
3.0 KiB
C

/* Copyright (C) 2005, 2008, 2009 Free Software Foundation, Inc.
Contributed by Richard Henderson <rth@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 file handles the SINGLE construct. */
#include "libgomp.h"
/* This routine is called when first encountering a SINGLE construct that
doesn't have a COPYPRIVATE clause. Returns true if this is the thread
that should execute the clause. */
bool
GOMP_single_start (void)
{
#ifdef HAVE_SYNC_BUILTINS
struct gomp_thread *thr = gomp_thread ();
struct gomp_team *team = thr->ts.team;
unsigned long single_count;
if (__builtin_expect (team == NULL, 0))
return true;
single_count = thr->ts.single_count++;
return __sync_bool_compare_and_swap (&team->single_count, single_count,
single_count + 1L);
#else
bool ret = gomp_work_share_start (false);
if (ret)
gomp_work_share_init_done ();
gomp_work_share_end_nowait ();
return ret;
#endif
}
/* This routine is called when first encountering a SINGLE construct that
does have a COPYPRIVATE clause. Returns NULL if this is the thread
that should execute the clause; otherwise the return value is pointer
given to GOMP_single_copy_end by the thread that did execute the clause. */
void *
GOMP_single_copy_start (void)
{
struct gomp_thread *thr = gomp_thread ();
bool first;
void *ret;
first = gomp_work_share_start (false);
if (first)
{
gomp_work_share_init_done ();
ret = NULL;
}
else
{
gomp_team_barrier_wait (&thr->ts.team->barrier);
ret = thr->ts.work_share->copyprivate;
gomp_work_share_end_nowait ();
}
return ret;
}
/* This routine is called when the thread that entered a SINGLE construct
with a COPYPRIVATE clause gets to the end of the construct. */
void
GOMP_single_copy_end (void *data)
{
struct gomp_thread *thr = gomp_thread ();
struct gomp_team *team = thr->ts.team;
if (team != NULL)
{
thr->ts.work_share->copyprivate = data;
gomp_team_barrier_wait (&team->barrier);
}
gomp_work_share_end_nowait ();
}