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-rw-r--r--libgomp/work.c264
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diff --git a/libgomp/work.c b/libgomp/work.c
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+/* Copyright (C) 2005, 2008, 2009 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 contains routines to manage the work-share queue for a team
+ of threads. */
+
+#include "libgomp.h"
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+/* Allocate a new work share structure, preferably from current team's
+ free gomp_work_share cache. */
+
+static struct gomp_work_share *
+alloc_work_share (struct gomp_team *team)
+{
+ struct gomp_work_share *ws;
+ unsigned int i;
+
+ /* This is called in a critical section. */
+ if (team->work_share_list_alloc != NULL)
+ {
+ ws = team->work_share_list_alloc;
+ team->work_share_list_alloc = ws->next_free;
+ return ws;
+ }
+
+#ifdef HAVE_SYNC_BUILTINS
+ ws = team->work_share_list_free;
+ /* We need atomic read from work_share_list_free,
+ as free_work_share can be called concurrently. */
+ __asm ("" : "+r" (ws));
+
+ if (ws && ws->next_free)
+ {
+ struct gomp_work_share *next = ws->next_free;
+ ws->next_free = NULL;
+ team->work_share_list_alloc = next->next_free;
+ return next;
+ }
+#else
+ gomp_mutex_lock (&team->work_share_list_free_lock);
+ ws = team->work_share_list_free;
+ if (ws)
+ {
+ team->work_share_list_alloc = ws->next_free;
+ team->work_share_list_free = NULL;
+ gomp_mutex_unlock (&team->work_share_list_free_lock);
+ return ws;
+ }
+ gomp_mutex_unlock (&team->work_share_list_free_lock);
+#endif
+
+ team->work_share_chunk *= 2;
+ ws = gomp_malloc (team->work_share_chunk * sizeof (struct gomp_work_share));
+ ws->next_alloc = team->work_shares[0].next_alloc;
+ team->work_shares[0].next_alloc = ws;
+ team->work_share_list_alloc = &ws[1];
+ for (i = 1; i < team->work_share_chunk - 1; i++)
+ ws[i].next_free = &ws[i + 1];
+ ws[i].next_free = NULL;
+ return ws;
+}
+
+/* Initialize an already allocated struct gomp_work_share.
+ This shouldn't touch the next_alloc field. */
+
+void
+gomp_init_work_share (struct gomp_work_share *ws, bool ordered,
+ unsigned nthreads)
+{
+ gomp_mutex_init (&ws->lock);
+ if (__builtin_expect (ordered, 0))
+ {
+#define INLINE_ORDERED_TEAM_IDS_CNT \
+ ((sizeof (struct gomp_work_share) \
+ - offsetof (struct gomp_work_share, inline_ordered_team_ids)) \
+ / sizeof (((struct gomp_work_share *) 0)->inline_ordered_team_ids[0]))
+
+ if (nthreads > INLINE_ORDERED_TEAM_IDS_CNT)
+ ws->ordered_team_ids
+ = gomp_malloc (nthreads * sizeof (*ws->ordered_team_ids));
+ else
+ ws->ordered_team_ids = ws->inline_ordered_team_ids;
+ memset (ws->ordered_team_ids, '\0',
+ nthreads * sizeof (*ws->ordered_team_ids));
+ ws->ordered_num_used = 0;
+ ws->ordered_owner = -1;
+ ws->ordered_cur = 0;
+ }
+ else
+ ws->ordered_team_ids = NULL;
+ gomp_ptrlock_init (&ws->next_ws, NULL);
+ ws->threads_completed = 0;
+}
+
+/* Do any needed destruction of gomp_work_share fields before it
+ is put back into free gomp_work_share cache or freed. */
+
+void
+gomp_fini_work_share (struct gomp_work_share *ws)
+{
+ gomp_mutex_destroy (&ws->lock);
+ if (ws->ordered_team_ids != ws->inline_ordered_team_ids)
+ free (ws->ordered_team_ids);
+ gomp_ptrlock_destroy (&ws->next_ws);
+}
+
+/* Free a work share struct, if not orphaned, put it into current
+ team's free gomp_work_share cache. */
+
+static inline void
+free_work_share (struct gomp_team *team, struct gomp_work_share *ws)
+{
+ gomp_fini_work_share (ws);
+ if (__builtin_expect (team == NULL, 0))
+ free (ws);
+ else
+ {
+ struct gomp_work_share *next_ws;
+#ifdef HAVE_SYNC_BUILTINS
+ do
+ {
+ next_ws = team->work_share_list_free;
+ ws->next_free = next_ws;
+ }
+ while (!__sync_bool_compare_and_swap (&team->work_share_list_free,
+ next_ws, ws));
+#else
+ gomp_mutex_lock (&team->work_share_list_free_lock);
+ next_ws = team->work_share_list_free;
+ ws->next_free = next_ws;
+ team->work_share_list_free = ws;
+ gomp_mutex_unlock (&team->work_share_list_free_lock);
+#endif
+ }
+}
+
+/* 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;
+
+ /* Work sharing constructs can be orphaned. */
+ if (team == NULL)
+ {
+ ws = gomp_malloc (sizeof (*ws));
+ gomp_init_work_share (ws, ordered, 1);
+ thr->ts.work_share = ws;
+ return ws;
+ }
+
+ ws = thr->ts.work_share;
+ thr->ts.last_work_share = ws;
+ ws = gomp_ptrlock_get (&ws->next_ws);
+ if (ws == NULL)
+ {
+ /* This thread encountered a new ws first. */
+ struct gomp_work_share *ws = alloc_work_share (team);
+ gomp_init_work_share (ws, ordered, team->nthreads);
+ thr->ts.work_share = ws;
+ return true;
+ }
+ else
+ {
+ thr->ts.work_share = ws;
+ return false;
+ }
+}
+
+/* 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;
+ gomp_barrier_state_t bstate;
+
+ /* Work sharing constructs can be orphaned. */
+ if (team == NULL)
+ {
+ free_work_share (NULL, thr->ts.work_share);
+ thr->ts.work_share = NULL;
+ return;
+ }
+
+ bstate = gomp_barrier_wait_start (&team->barrier);
+
+ if (gomp_barrier_last_thread (bstate))
+ {
+ if (__builtin_expect (thr->ts.last_work_share != NULL, 1))
+ free_work_share (team, thr->ts.last_work_share);
+ }
+
+ gomp_team_barrier_wait_end (&team->barrier, bstate);
+ thr->ts.last_work_share = NULL;
+}
+
+/* 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;
+
+ /* Work sharing constructs can be orphaned. */
+ if (team == NULL)
+ {
+ free_work_share (NULL, ws);
+ thr->ts.work_share = NULL;
+ return;
+ }
+
+ if (__builtin_expect (thr->ts.last_work_share == NULL, 0))
+ 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)
+ free_work_share (team, thr->ts.last_work_share);
+ thr->ts.last_work_share = NULL;
+}
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