gcc/libgomp/config/rtems/bar.c
2021-01-04 10:26:59 +01:00

77 lines
2.3 KiB
C

/* Copyright (C) 2005-2021 Free Software Foundation, Inc.
Contributed by Sebastian Huber <sebastian.huber@embedded-brains.de>.
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 the RTEMS implementation of a barrier synchronization
mechanism for libgomp. It is identical to the Linux implementation, except
that the futex API is slightly different. This type is private to the
library. */
#include "libgomp.h"
#include "bar.h"
#include <limits.h>
static gomp_barrier_t *
generation_to_barrier (int *addr)
{
return (gomp_barrier_t *)
((char *) addr - __builtin_offsetof (gomp_barrier_t, generation));
}
static void
futex_wait (int *addr, int val)
{
gomp_barrier_t *bar = generation_to_barrier (addr);
_Futex_Wait (&bar->futex, addr, val);
}
static void
futex_wake (int *addr, int count)
{
gomp_barrier_t *bar = generation_to_barrier (addr);
_Futex_Wake (&bar->futex, count);
}
static int
do_spin (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 (__atomic_load_n (addr, MEMMODEL_RELAXED) != val, 0))
return 0;
return 1;
}
static void
do_wait (int *addr, int val)
{
if (do_spin (addr, val))
futex_wait (addr, val);
}
#define GOMP_WAIT_H 1
#include "../linux/bar.c"