149 lines
3.8 KiB
C
149 lines
3.8 KiB
C
/* Copyright (C) 2005-2013 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 CRITICAL construct. */
|
|
|
|
#include "libgomp.h"
|
|
#include <stdlib.h>
|
|
|
|
|
|
static gomp_mutex_t default_lock;
|
|
|
|
void
|
|
GOMP_critical_start (void)
|
|
{
|
|
/* There is an implicit flush on entry to a critical region. */
|
|
__atomic_thread_fence (MEMMODEL_RELEASE);
|
|
gomp_mutex_lock (&default_lock);
|
|
}
|
|
|
|
void
|
|
GOMP_critical_end (void)
|
|
{
|
|
gomp_mutex_unlock (&default_lock);
|
|
}
|
|
|
|
#ifndef HAVE_SYNC_BUILTINS
|
|
static gomp_mutex_t create_lock_lock;
|
|
#endif
|
|
|
|
void
|
|
GOMP_critical_name_start (void **pptr)
|
|
{
|
|
gomp_mutex_t *plock;
|
|
|
|
/* If a mutex fits within the space for a pointer, and is zero initialized,
|
|
then use the pointer space directly. */
|
|
if (GOMP_MUTEX_INIT_0
|
|
&& sizeof (gomp_mutex_t) <= sizeof (void *)
|
|
&& __alignof (gomp_mutex_t) <= sizeof (void *))
|
|
plock = (gomp_mutex_t *)pptr;
|
|
|
|
/* Otherwise we have to be prepared to malloc storage. */
|
|
else
|
|
{
|
|
plock = *pptr;
|
|
|
|
if (plock == NULL)
|
|
{
|
|
#ifdef HAVE_SYNC_BUILTINS
|
|
gomp_mutex_t *nlock = gomp_malloc (sizeof (gomp_mutex_t));
|
|
gomp_mutex_init (nlock);
|
|
|
|
plock = __sync_val_compare_and_swap (pptr, NULL, nlock);
|
|
if (plock != NULL)
|
|
{
|
|
gomp_mutex_destroy (nlock);
|
|
free (nlock);
|
|
}
|
|
else
|
|
plock = nlock;
|
|
#else
|
|
gomp_mutex_lock (&create_lock_lock);
|
|
plock = *pptr;
|
|
if (plock == NULL)
|
|
{
|
|
plock = gomp_malloc (sizeof (gomp_mutex_t));
|
|
gomp_mutex_init (plock);
|
|
__sync_synchronize ();
|
|
*pptr = plock;
|
|
}
|
|
gomp_mutex_unlock (&create_lock_lock);
|
|
#endif
|
|
}
|
|
}
|
|
|
|
gomp_mutex_lock (plock);
|
|
}
|
|
|
|
void
|
|
GOMP_critical_name_end (void **pptr)
|
|
{
|
|
gomp_mutex_t *plock;
|
|
|
|
/* If a mutex fits within the space for a pointer, and is zero initialized,
|
|
then use the pointer space directly. */
|
|
if (GOMP_MUTEX_INIT_0
|
|
&& sizeof (gomp_mutex_t) <= sizeof (void *)
|
|
&& __alignof (gomp_mutex_t) <= sizeof (void *))
|
|
plock = (gomp_mutex_t *)pptr;
|
|
else
|
|
plock = *pptr;
|
|
|
|
gomp_mutex_unlock (plock);
|
|
}
|
|
|
|
/* This mutex is used when atomic operations don't exist for the target
|
|
in the mode requested. The result is not globally atomic, but works so
|
|
long as all parallel references are within #pragma omp atomic directives.
|
|
According to responses received from omp@openmp.org, appears to be within
|
|
spec. Which makes sense, since that's how several other compilers
|
|
handle this situation as well. */
|
|
|
|
static gomp_mutex_t atomic_lock;
|
|
|
|
void
|
|
GOMP_atomic_start (void)
|
|
{
|
|
gomp_mutex_lock (&atomic_lock);
|
|
}
|
|
|
|
void
|
|
GOMP_atomic_end (void)
|
|
{
|
|
gomp_mutex_unlock (&atomic_lock);
|
|
}
|
|
|
|
#if !GOMP_MUTEX_INIT_0
|
|
static void __attribute__((constructor))
|
|
initialize_critical (void)
|
|
{
|
|
gomp_mutex_init (&default_lock);
|
|
gomp_mutex_init (&atomic_lock);
|
|
#ifndef HAVE_SYNC_BUILTINS
|
|
gomp_mutex_init (&create_lock_lock);
|
|
#endif
|
|
}
|
|
#endif
|