224 lines
6.1 KiB
C
224 lines
6.1 KiB
C
/* Copyright (C) 2005 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 Lesser General Public License as published by
|
|
the Free Software Foundation; either version 2.1 of the License, 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 Lesser General Public License for
|
|
more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
along with libgomp; see the file COPYING.LIB. If not, write to the
|
|
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
|
|
MA 02110-1301, USA. */
|
|
|
|
/* As a special exception, if you link this library with other files, some
|
|
of which are compiled with GCC, to produce an executable, this library
|
|
does not by itself cause the resulting executable to be covered by the
|
|
GNU General Public License. This exception does not however invalidate
|
|
any other reasons why the executable file might be covered by the GNU
|
|
General Public License. */
|
|
|
|
/* This file contains routines to manage the work-share queue for a team
|
|
of threads. */
|
|
|
|
#include "libgomp.h"
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
|
|
/* Create a new work share structure. */
|
|
|
|
struct gomp_work_share *
|
|
gomp_new_work_share (bool ordered, unsigned nthreads)
|
|
{
|
|
struct gomp_work_share *ws;
|
|
size_t size;
|
|
|
|
size = sizeof (*ws);
|
|
if (ordered)
|
|
size += nthreads * sizeof (ws->ordered_team_ids[0]);
|
|
|
|
ws = gomp_malloc_cleared (size);
|
|
gomp_mutex_init (&ws->lock);
|
|
ws->ordered_owner = -1;
|
|
|
|
return ws;
|
|
}
|
|
|
|
|
|
/* Free a work share structure. */
|
|
|
|
static void
|
|
free_work_share (struct gomp_work_share *ws)
|
|
{
|
|
gomp_mutex_destroy (&ws->lock);
|
|
free (ws);
|
|
}
|
|
|
|
|
|
/* The current thread is ready to begin the next work sharing construct.
|
|
In all cases, thr->ts.work_share is updated to point to the new
|
|
structure. In all cases the work_share lock is locked. Return true
|
|
if this was the first thread to reach this point. */
|
|
|
|
bool
|
|
gomp_work_share_start (bool ordered)
|
|
{
|
|
struct gomp_thread *thr = gomp_thread ();
|
|
struct gomp_team *team = thr->ts.team;
|
|
struct gomp_work_share *ws;
|
|
unsigned ws_index, ws_gen;
|
|
|
|
/* Work sharing constructs can be orphaned. */
|
|
if (team == NULL)
|
|
{
|
|
ws = gomp_new_work_share (ordered, 1);
|
|
thr->ts.work_share = ws;
|
|
thr->ts.static_trip = 0;
|
|
gomp_mutex_lock (&ws->lock);
|
|
return true;
|
|
}
|
|
|
|
gomp_mutex_lock (&team->work_share_lock);
|
|
|
|
/* This thread is beginning its next generation. */
|
|
ws_gen = ++thr->ts.work_share_generation;
|
|
|
|
/* If this next generation is not newer than any other generation in
|
|
the team, then simply reference the existing construct. */
|
|
if (ws_gen - team->oldest_live_gen < team->num_live_gen)
|
|
{
|
|
ws_index = ws_gen & team->generation_mask;
|
|
ws = team->work_shares[ws_index];
|
|
thr->ts.work_share = ws;
|
|
thr->ts.static_trip = 0;
|
|
|
|
gomp_mutex_lock (&ws->lock);
|
|
gomp_mutex_unlock (&team->work_share_lock);
|
|
|
|
return false;
|
|
}
|
|
|
|
/* Resize the work shares queue if we've run out of space. */
|
|
if (team->num_live_gen++ == team->generation_mask)
|
|
{
|
|
team->work_shares = gomp_realloc (team->work_shares,
|
|
2 * team->num_live_gen
|
|
* sizeof (*team->work_shares));
|
|
|
|
/* Unless oldest_live_gen is zero, the sequence of live elements
|
|
wraps around the end of the array. If we do nothing, we break
|
|
lookup of the existing elements. Fix that by unwrapping the
|
|
data from the front to the end. */
|
|
if (team->oldest_live_gen > 0)
|
|
memcpy (team->work_shares + team->num_live_gen,
|
|
team->work_shares,
|
|
(team->oldest_live_gen & team->generation_mask)
|
|
* sizeof (*team->work_shares));
|
|
|
|
team->generation_mask = team->generation_mask * 2 + 1;
|
|
}
|
|
|
|
ws_index = ws_gen & team->generation_mask;
|
|
ws = gomp_new_work_share (ordered, team->nthreads);
|
|
thr->ts.work_share = ws;
|
|
thr->ts.static_trip = 0;
|
|
team->work_shares[ws_index] = ws;
|
|
|
|
gomp_mutex_lock (&ws->lock);
|
|
gomp_mutex_unlock (&team->work_share_lock);
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
/* The current thread is done with its current work sharing construct.
|
|
This version does imply a barrier at the end of the work-share. */
|
|
|
|
void
|
|
gomp_work_share_end (void)
|
|
{
|
|
struct gomp_thread *thr = gomp_thread ();
|
|
struct gomp_team *team = thr->ts.team;
|
|
struct gomp_work_share *ws = thr->ts.work_share;
|
|
bool last;
|
|
|
|
thr->ts.work_share = NULL;
|
|
|
|
/* Work sharing constructs can be orphaned. */
|
|
if (team == NULL)
|
|
{
|
|
free_work_share (ws);
|
|
return;
|
|
}
|
|
|
|
last = gomp_barrier_wait_start (&team->barrier);
|
|
|
|
if (last)
|
|
{
|
|
unsigned ws_index;
|
|
|
|
ws_index = thr->ts.work_share_generation & team->generation_mask;
|
|
team->work_shares[ws_index] = NULL;
|
|
team->oldest_live_gen++;
|
|
team->num_live_gen = 0;
|
|
|
|
free_work_share (ws);
|
|
}
|
|
|
|
gomp_barrier_wait_end (&team->barrier, last);
|
|
}
|
|
|
|
|
|
/* The current thread is done with its current work sharing construct.
|
|
This version does NOT imply a barrier at the end of the work-share. */
|
|
|
|
void
|
|
gomp_work_share_end_nowait (void)
|
|
{
|
|
struct gomp_thread *thr = gomp_thread ();
|
|
struct gomp_team *team = thr->ts.team;
|
|
struct gomp_work_share *ws = thr->ts.work_share;
|
|
unsigned completed;
|
|
|
|
thr->ts.work_share = NULL;
|
|
|
|
/* Work sharing constructs can be orphaned. */
|
|
if (team == NULL)
|
|
{
|
|
free_work_share (ws);
|
|
return;
|
|
}
|
|
|
|
#ifdef HAVE_SYNC_BUILTINS
|
|
completed = __sync_add_and_fetch (&ws->threads_completed, 1);
|
|
#else
|
|
gomp_mutex_lock (&ws->lock);
|
|
completed = ++ws->threads_completed;
|
|
gomp_mutex_unlock (&ws->lock);
|
|
#endif
|
|
|
|
if (completed == team->nthreads)
|
|
{
|
|
unsigned ws_index;
|
|
|
|
gomp_mutex_lock (&team->work_share_lock);
|
|
|
|
ws_index = thr->ts.work_share_generation & team->generation_mask;
|
|
team->work_shares[ws_index] = NULL;
|
|
team->oldest_live_gen++;
|
|
team->num_live_gen--;
|
|
|
|
gomp_mutex_unlock (&team->work_share_lock);
|
|
|
|
free_work_share (ws);
|
|
}
|
|
}
|