mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-12 11:29:30 +00:00
303 lines
8.2 KiB
C
303 lines
8.2 KiB
C
/* Copyright (C) 2005-2018 Free Software Foundation, Inc.
|
||
Contributed by Richard Henderson <rth@redhat.com>.
|
||
|
||
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 file handles the (bare) PARALLEL construct. */
|
||
|
||
#include "libgomp.h"
|
||
#include <limits.h>
|
||
|
||
|
||
/* Determine the number of threads to be launched for a PARALLEL construct.
|
||
This algorithm is explicitly described in OpenMP 3.0 section 2.4.1.
|
||
SPECIFIED is a combination of the NUM_THREADS clause and the IF clause.
|
||
If the IF clause is false, SPECIFIED is forced to 1. When NUM_THREADS
|
||
is not present, SPECIFIED is 0. */
|
||
|
||
unsigned
|
||
gomp_resolve_num_threads (unsigned specified, unsigned count)
|
||
{
|
||
struct gomp_thread *thr = gomp_thread ();
|
||
struct gomp_task_icv *icv;
|
||
unsigned threads_requested, max_num_threads, num_threads;
|
||
unsigned long busy;
|
||
struct gomp_thread_pool *pool;
|
||
|
||
icv = gomp_icv (false);
|
||
|
||
if (specified == 1)
|
||
return 1;
|
||
else if (thr->ts.active_level >= 1 && !icv->nest_var)
|
||
return 1;
|
||
else if (thr->ts.active_level >= gomp_max_active_levels_var)
|
||
return 1;
|
||
|
||
/* If NUM_THREADS not specified, use nthreads_var. */
|
||
if (specified == 0)
|
||
threads_requested = icv->nthreads_var;
|
||
else
|
||
threads_requested = specified;
|
||
|
||
max_num_threads = threads_requested;
|
||
|
||
/* If dynamic threads are enabled, bound the number of threads
|
||
that we launch. */
|
||
if (icv->dyn_var)
|
||
{
|
||
unsigned dyn = gomp_dynamic_max_threads ();
|
||
if (dyn < max_num_threads)
|
||
max_num_threads = dyn;
|
||
|
||
/* Optimization for parallel sections. */
|
||
if (count && count < max_num_threads)
|
||
max_num_threads = count;
|
||
}
|
||
|
||
/* UINT_MAX stands for infinity. */
|
||
if (__builtin_expect (icv->thread_limit_var == UINT_MAX, 1)
|
||
|| max_num_threads == 1)
|
||
return max_num_threads;
|
||
|
||
/* The threads_busy counter lives in thread_pool, if there
|
||
isn't a thread_pool yet, there must be just one thread
|
||
in the contention group. If thr->team is NULL, this isn't
|
||
nested parallel, so there is just one thread in the
|
||
contention group as well, no need to handle it atomically. */
|
||
pool = thr->thread_pool;
|
||
if (thr->ts.team == NULL || pool == NULL)
|
||
{
|
||
num_threads = max_num_threads;
|
||
if (num_threads > icv->thread_limit_var)
|
||
num_threads = icv->thread_limit_var;
|
||
if (pool)
|
||
pool->threads_busy = num_threads;
|
||
return num_threads;
|
||
}
|
||
|
||
#ifdef HAVE_SYNC_BUILTINS
|
||
do
|
||
{
|
||
busy = pool->threads_busy;
|
||
num_threads = max_num_threads;
|
||
if (icv->thread_limit_var - busy + 1 < num_threads)
|
||
num_threads = icv->thread_limit_var - busy + 1;
|
||
}
|
||
while (__sync_val_compare_and_swap (&pool->threads_busy,
|
||
busy, busy + num_threads - 1)
|
||
!= busy);
|
||
#else
|
||
gomp_mutex_lock (&gomp_managed_threads_lock);
|
||
num_threads = max_num_threads;
|
||
busy = pool->threads_busy;
|
||
if (icv->thread_limit_var - busy + 1 < num_threads)
|
||
num_threads = icv->thread_limit_var - busy + 1;
|
||
pool->threads_busy += num_threads - 1;
|
||
gomp_mutex_unlock (&gomp_managed_threads_lock);
|
||
#endif
|
||
|
||
return num_threads;
|
||
}
|
||
|
||
void
|
||
GOMP_parallel_start (void (*fn) (void *), void *data, unsigned num_threads)
|
||
{
|
||
num_threads = gomp_resolve_num_threads (num_threads, 0);
|
||
gomp_team_start (fn, data, num_threads, 0, gomp_new_team (num_threads));
|
||
}
|
||
|
||
void
|
||
GOMP_parallel_end (void)
|
||
{
|
||
struct gomp_task_icv *icv = gomp_icv (false);
|
||
if (__builtin_expect (icv->thread_limit_var != UINT_MAX, 0))
|
||
{
|
||
struct gomp_thread *thr = gomp_thread ();
|
||
struct gomp_team *team = thr->ts.team;
|
||
unsigned int nthreads = team ? team->nthreads : 1;
|
||
gomp_team_end ();
|
||
if (nthreads > 1)
|
||
{
|
||
/* If not nested, there is just one thread in the
|
||
contention group left, no need for atomicity. */
|
||
if (thr->ts.team == NULL)
|
||
thr->thread_pool->threads_busy = 1;
|
||
else
|
||
{
|
||
#ifdef HAVE_SYNC_BUILTINS
|
||
__sync_fetch_and_add (&thr->thread_pool->threads_busy,
|
||
1UL - nthreads);
|
||
#else
|
||
gomp_mutex_lock (&gomp_managed_threads_lock);
|
||
thr->thread_pool->threads_busy -= nthreads - 1;
|
||
gomp_mutex_unlock (&gomp_managed_threads_lock);
|
||
#endif
|
||
}
|
||
}
|
||
}
|
||
else
|
||
gomp_team_end ();
|
||
}
|
||
ialias (GOMP_parallel_end)
|
||
|
||
void
|
||
GOMP_parallel (void (*fn) (void *), void *data, unsigned num_threads, unsigned int flags)
|
||
{
|
||
num_threads = gomp_resolve_num_threads (num_threads, 0);
|
||
gomp_team_start (fn, data, num_threads, flags, gomp_new_team (num_threads));
|
||
fn (data);
|
||
ialias_call (GOMP_parallel_end) ();
|
||
}
|
||
|
||
bool
|
||
GOMP_cancellation_point (int which)
|
||
{
|
||
if (!gomp_cancel_var)
|
||
return false;
|
||
|
||
struct gomp_thread *thr = gomp_thread ();
|
||
struct gomp_team *team = thr->ts.team;
|
||
if (which & (GOMP_CANCEL_LOOP | GOMP_CANCEL_SECTIONS))
|
||
{
|
||
if (team == NULL)
|
||
return false;
|
||
return team->work_share_cancelled != 0;
|
||
}
|
||
else if (which & GOMP_CANCEL_TASKGROUP)
|
||
{
|
||
if (thr->task->taskgroup && thr->task->taskgroup->cancelled)
|
||
return true;
|
||
/* FALLTHRU into the GOMP_CANCEL_PARALLEL case,
|
||
as #pragma omp cancel parallel also cancels all explicit
|
||
tasks. */
|
||
}
|
||
if (team)
|
||
return gomp_team_barrier_cancelled (&team->barrier);
|
||
return false;
|
||
}
|
||
ialias (GOMP_cancellation_point)
|
||
|
||
bool
|
||
GOMP_cancel (int which, bool do_cancel)
|
||
{
|
||
if (!gomp_cancel_var)
|
||
return false;
|
||
|
||
if (!do_cancel)
|
||
return ialias_call (GOMP_cancellation_point) (which);
|
||
|
||
struct gomp_thread *thr = gomp_thread ();
|
||
struct gomp_team *team = thr->ts.team;
|
||
if (which & (GOMP_CANCEL_LOOP | GOMP_CANCEL_SECTIONS))
|
||
{
|
||
/* In orphaned worksharing region, all we want to cancel
|
||
is current thread. */
|
||
if (team != NULL)
|
||
team->work_share_cancelled = 1;
|
||
return true;
|
||
}
|
||
else if (which & GOMP_CANCEL_TASKGROUP)
|
||
{
|
||
if (thr->task->taskgroup && !thr->task->taskgroup->cancelled)
|
||
{
|
||
gomp_mutex_lock (&team->task_lock);
|
||
thr->task->taskgroup->cancelled = true;
|
||
gomp_mutex_unlock (&team->task_lock);
|
||
}
|
||
return true;
|
||
}
|
||
team->team_cancelled = 1;
|
||
gomp_team_barrier_cancel (team);
|
||
return true;
|
||
}
|
||
|
||
/* The public OpenMP API for thread and team related inquiries. */
|
||
|
||
int
|
||
omp_get_num_threads (void)
|
||
{
|
||
struct gomp_team *team = gomp_thread ()->ts.team;
|
||
return team ? team->nthreads : 1;
|
||
}
|
||
|
||
int
|
||
omp_get_thread_num (void)
|
||
{
|
||
return gomp_thread ()->ts.team_id;
|
||
}
|
||
|
||
/* This wasn't right for OpenMP 2.5. Active region used to be non-zero
|
||
when the IF clause doesn't evaluate to false, starting with OpenMP 3.0
|
||
it is non-zero with more than one thread in the team. */
|
||
|
||
int
|
||
omp_in_parallel (void)
|
||
{
|
||
return gomp_thread ()->ts.active_level > 0;
|
||
}
|
||
|
||
int
|
||
omp_get_level (void)
|
||
{
|
||
return gomp_thread ()->ts.level;
|
||
}
|
||
|
||
int
|
||
omp_get_ancestor_thread_num (int level)
|
||
{
|
||
struct gomp_team_state *ts = &gomp_thread ()->ts;
|
||
if (level < 0 || level > ts->level)
|
||
return -1;
|
||
for (level = ts->level - level; level > 0; --level)
|
||
ts = &ts->team->prev_ts;
|
||
return ts->team_id;
|
||
}
|
||
|
||
int
|
||
omp_get_team_size (int level)
|
||
{
|
||
struct gomp_team_state *ts = &gomp_thread ()->ts;
|
||
if (level < 0 || level > ts->level)
|
||
return -1;
|
||
for (level = ts->level - level; level > 0; --level)
|
||
ts = &ts->team->prev_ts;
|
||
if (ts->team == NULL)
|
||
return 1;
|
||
else
|
||
return ts->team->nthreads;
|
||
}
|
||
|
||
int
|
||
omp_get_active_level (void)
|
||
{
|
||
return gomp_thread ()->ts.active_level;
|
||
}
|
||
|
||
ialias (omp_get_num_threads)
|
||
ialias (omp_get_thread_num)
|
||
ialias (omp_in_parallel)
|
||
ialias (omp_get_level)
|
||
ialias (omp_get_ancestor_thread_num)
|
||
ialias (omp_get_team_size)
|
||
ialias (omp_get_active_level)
|