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/* Copyright (C) 2015-2019 Free Software Foundation, Inc.
Contributed by Sebastian Huber <sebastian.huber@embedded-brains.de>.
This file is part of the GNU Offloading and Multi Processing 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 the thread pool management
for libgomp. This type is private to the library. */
#ifndef GOMP_POOL_H
#define GOMP_POOL_H 1
#include "libgomp.h"
#include <sys/lock.h>
#include <string.h>
/* For each scheduler instance there may be a thread pool reservoir
to limit the number of thread pools used by the OpenMP master threads of this
scheduler instance. The reservoirs are configured via the
GOMP_RTEMS_THREAD_POOLS environment variable. */
struct gomp_thread_pool_reservoir {
gomp_sem_t available;
pthread_spinlock_t lock;
size_t index;
int priority;
struct gomp_thread_pool *pools[];
};
struct gomp_tls_rtems_data {
struct gomp_thread_pool_reservoir *thread_pool_reservoir;
};
extern struct gomp_thread_pool_reservoir **gomp_thread_pool_reservoirs;
extern __thread struct gomp_tls_rtems_data gomp_tls_rtems_data;
static inline struct gomp_thread_pool_reservoir *
gomp_get_thread_pool_reservoir (void)
{
struct gomp_thread_pool_reservoir *res =
gomp_tls_rtems_data.thread_pool_reservoir;
if (res == NULL && gomp_thread_pool_reservoirs != NULL)
{
struct gomp_thread *thr = gomp_thread ();
thr->thread_pool = gomp_malloc_cleared (sizeof (*thr->thread_pool));
res = gomp_thread_pool_reservoirs[_Sched_Index ()];
gomp_tls_rtems_data.thread_pool_reservoir = res;
}
return res;
}
static inline struct gomp_thread_pool *
gomp_get_own_thread_pool (struct gomp_thread *thr, unsigned nthreads)
{
struct gomp_thread_pool *pool = thr->thread_pool;
if (__builtin_expect (pool == NULL, 0))
{
pool = gomp_malloc_cleared (sizeof (*pool));
pool->threads_busy = nthreads;
thr->thread_pool = pool;
}
return pool;
}
static inline struct gomp_thread_pool *
gomp_get_thread_pool (struct gomp_thread *thr, unsigned nthreads)
{
struct gomp_thread_pool *pool;
struct gomp_thread_pool_reservoir *res;
if (__builtin_expect (thr->thread_pool == NULL, 0))
pthread_setspecific (gomp_thread_destructor, thr);
res = gomp_get_thread_pool_reservoir ();
if (res != NULL)
{
gomp_sem_wait (&res->available);
pthread_spin_lock (&res->lock);
pool = res->pools[--res->index];
pthread_spin_unlock (&res->lock);
pool->threads_busy = nthreads;
thr->thread_pool = pool;
}
else
pool = gomp_get_own_thread_pool (thr, nthreads);
return pool;
}
static inline void
gomp_release_thread_pool (struct gomp_thread_pool *pool)
{
struct gomp_thread_pool_reservoir *res =
gomp_tls_rtems_data.thread_pool_reservoir;
if (res != NULL)
{
pthread_spin_lock (&res->lock);
res->pools[res->index++] = pool;
pthread_spin_unlock (&res->lock);
gomp_sem_post (&res->available);
}
}
static inline pthread_attr_t *
gomp_adjust_thread_attr (pthread_attr_t *attr, pthread_attr_t *mutable_attr)
{
struct gomp_thread_pool_reservoir *res = gomp_get_thread_pool_reservoir ();
if (res != NULL && res->priority > 0)
{
struct sched_param param;
int err;
if (attr != mutable_attr)
{
attr = mutable_attr;
pthread_attr_init (attr);
}
memset (&param, 0, sizeof (param));
param.sched_priority = res->priority;
err = pthread_attr_setschedparam (attr, &param);
if (err != 0)
gomp_fatal ("Thread attribute set scheduler parameters failed: %s", strerror (err));
err = pthread_attr_setschedpolicy (attr, SCHED_FIFO);
if (err != 0)
gomp_fatal ("Thread attribute set scheduler policy failed: %s", strerror (err));
err = pthread_attr_setinheritsched (attr, PTHREAD_EXPLICIT_SCHED);
if (err != 0)
gomp_fatal ("Thread attribute set explicit scheduler failed: %s", strerror (err));
}
return attr;
}
#endif /* GOMP_POOL_H */