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+/* Copyright (C) 2007, 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 handles the maintainence of tasks in response to task
+ creation and termination. */
+
+#include "libgomp.h"
+#include <stdlib.h>
+#include <string.h>
+
+
+/* Create a new task data structure. */
+
+void
+gomp_init_task (struct gomp_task *task, struct gomp_task *parent_task,
+ struct gomp_task_icv *prev_icv)
+{
+ task->parent = parent_task;
+ task->icv = *prev_icv;
+ task->kind = GOMP_TASK_IMPLICIT;
+ task->in_taskwait = false;
+ task->in_tied_task = false;
+ task->children = NULL;
+ gomp_sem_init (&task->taskwait_sem, 0);
+}
+
+/* Clean up a task, after completing it. */
+
+void
+gomp_end_task (void)
+{
+ struct gomp_thread *thr = gomp_thread ();
+ struct gomp_task *task = thr->task;
+
+ gomp_finish_task (task);
+ thr->task = task->parent;
+}
+
+static inline void
+gomp_clear_parent (struct gomp_task *children)
+{
+ struct gomp_task *task = children;
+
+ if (task)
+ do
+ {
+ task->parent = NULL;
+ task = task->next_child;
+ }
+ while (task != children);
+}
+
+/* Called when encountering an explicit task directive. If IF_CLAUSE is
+ false, then we must not delay in executing the task. If UNTIED is true,
+ then the task may be executed by any member of the team. */
+
+void
+GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *),
+ long arg_size, long arg_align, bool if_clause,
+ unsigned flags __attribute__((unused)))
+{
+ struct gomp_thread *thr = gomp_thread ();
+ struct gomp_team *team = thr->ts.team;
+
+#ifdef HAVE_BROKEN_POSIX_SEMAPHORES
+ /* If pthread_mutex_* is used for omp_*lock*, then each task must be
+ tied to one thread all the time. This means UNTIED tasks must be
+ tied and if CPYFN is non-NULL IF(0) must be forced, as CPYFN
+ might be running on different thread than FN. */
+ if (cpyfn)
+ if_clause = false;
+ if (flags & 1)
+ flags &= ~1;
+#endif
+
+ if (!if_clause || team == NULL
+ || team->task_count > 64 * team->nthreads)
+ {
+ struct gomp_task task;
+
+ gomp_init_task (&task, thr->task, gomp_icv (false));
+ task.kind = GOMP_TASK_IFFALSE;
+ if (thr->task)
+ task.in_tied_task = thr->task->in_tied_task;
+ thr->task = &task;
+ if (__builtin_expect (cpyfn != NULL, 0))
+ {
+ char buf[arg_size + arg_align - 1];
+ char *arg = (char *) (((uintptr_t) buf + arg_align - 1)
+ & ~(uintptr_t) (arg_align - 1));
+ cpyfn (arg, data);
+ fn (arg);
+ }
+ else
+ fn (data);
+ if (task.children)
+ {
+ gomp_mutex_lock (&team->task_lock);
+ gomp_clear_parent (task.children);
+ gomp_mutex_unlock (&team->task_lock);
+ }
+ gomp_end_task ();
+ }
+ else
+ {
+ struct gomp_task *task;
+ struct gomp_task *parent = thr->task;
+ char *arg;
+ bool do_wake;
+
+ task = gomp_malloc (sizeof (*task) + arg_size + arg_align - 1);
+ arg = (char *) (((uintptr_t) (task + 1) + arg_align - 1)
+ & ~(uintptr_t) (arg_align - 1));
+ gomp_init_task (task, parent, gomp_icv (false));
+ task->kind = GOMP_TASK_IFFALSE;
+ task->in_tied_task = parent->in_tied_task;
+ thr->task = task;
+ if (cpyfn)
+ cpyfn (arg, data);
+ else
+ memcpy (arg, data, arg_size);
+ thr->task = parent;
+ task->kind = GOMP_TASK_WAITING;
+ task->fn = fn;
+ task->fn_data = arg;
+ task->in_tied_task = true;
+ gomp_mutex_lock (&team->task_lock);
+ if (parent->children)
+ {
+ task->next_child = parent->children;
+ task->prev_child = parent->children->prev_child;
+ task->next_child->prev_child = task;
+ task->prev_child->next_child = task;
+ }
+ else
+ {
+ task->next_child = task;
+ task->prev_child = task;
+ }
+ parent->children = task;
+ if (team->task_queue)
+ {
+ task->next_queue = team->task_queue;
+ task->prev_queue = team->task_queue->prev_queue;
+ task->next_queue->prev_queue = task;
+ task->prev_queue->next_queue = task;
+ }
+ else
+ {
+ task->next_queue = task;
+ task->prev_queue = task;
+ team->task_queue = task;
+ }
+ ++team->task_count;
+ gomp_team_barrier_set_task_pending (&team->barrier);
+ do_wake = team->task_running_count + !parent->in_tied_task
+ < team->nthreads;
+ gomp_mutex_unlock (&team->task_lock);
+ if (do_wake)
+ gomp_team_barrier_wake (&team->barrier, 1);
+ }
+}
+
+void
+gomp_barrier_handle_tasks (gomp_barrier_state_t state)
+{
+ struct gomp_thread *thr = gomp_thread ();
+ struct gomp_team *team = thr->ts.team;
+ struct gomp_task *task = thr->task;
+ struct gomp_task *child_task = NULL;
+ struct gomp_task *to_free = NULL;
+
+ gomp_mutex_lock (&team->task_lock);
+ if (gomp_barrier_last_thread (state))
+ {
+ if (team->task_count == 0)
+ {
+ gomp_team_barrier_done (&team->barrier, state);
+ gomp_mutex_unlock (&team->task_lock);
+ gomp_team_barrier_wake (&team->barrier, 0);
+ return;
+ }
+ gomp_team_barrier_set_waiting_for_tasks (&team->barrier);
+ }
+
+ while (1)
+ {
+ if (team->task_queue != NULL)
+ {
+ struct gomp_task *parent;
+
+ child_task = team->task_queue;
+ parent = child_task->parent;
+ if (parent && parent->children == child_task)
+ parent->children = child_task->next_child;
+ child_task->prev_queue->next_queue = child_task->next_queue;
+ child_task->next_queue->prev_queue = child_task->prev_queue;
+ if (child_task->next_queue != child_task)
+ team->task_queue = child_task->next_queue;
+ else
+ team->task_queue = NULL;
+ child_task->kind = GOMP_TASK_TIED;
+ team->task_running_count++;
+ if (team->task_count == team->task_running_count)
+ gomp_team_barrier_clear_task_pending (&team->barrier);
+ }
+ gomp_mutex_unlock (&team->task_lock);
+ if (to_free)
+ {
+ gomp_finish_task (to_free);
+ free (to_free);
+ to_free = NULL;
+ }
+ if (child_task)
+ {
+ thr->task = child_task;
+ child_task->fn (child_task->fn_data);
+ thr->task = task;
+ }
+ else
+ return;
+ gomp_mutex_lock (&team->task_lock);
+ if (child_task)
+ {
+ struct gomp_task *parent = child_task->parent;
+ if (parent)
+ {
+ child_task->prev_child->next_child = child_task->next_child;
+ child_task->next_child->prev_child = child_task->prev_child;
+ if (parent->children == child_task)
+ {
+ if (child_task->next_child != child_task)
+ parent->children = child_task->next_child;
+ else
+ {
+ parent->children = NULL;
+ if (parent->in_taskwait)
+ gomp_sem_post (&parent->taskwait_sem);
+ }
+ }
+ }
+ gomp_clear_parent (child_task->children);
+ to_free = child_task;
+ child_task = NULL;
+ team->task_running_count--;
+ if (--team->task_count == 0
+ && gomp_team_barrier_waiting_for_tasks (&team->barrier))
+ {
+ gomp_team_barrier_done (&team->barrier, state);
+ gomp_mutex_unlock (&team->task_lock);
+ gomp_team_barrier_wake (&team->barrier, 0);
+ }
+ }
+ }
+}
+
+/* Called when encountering a taskwait directive. */
+
+void
+GOMP_taskwait (void)
+{
+ struct gomp_thread *thr = gomp_thread ();
+ struct gomp_team *team = thr->ts.team;
+ struct gomp_task *task = thr->task;
+ struct gomp_task *child_task = NULL;
+ struct gomp_task *to_free = NULL;
+
+ if (task == NULL || task->children == NULL)
+ return;
+ gomp_mutex_lock (&team->task_lock);
+ while (1)
+ {
+ if (task->children == NULL)
+ {
+ gomp_mutex_unlock (&team->task_lock);
+ if (to_free)
+ {
+ gomp_finish_task (to_free);
+ free (to_free);
+ }
+ return;
+ }
+ if (task->children->kind == GOMP_TASK_WAITING)
+ {
+ child_task = task->children;
+ task->children = child_task->next_child;
+ child_task->prev_queue->next_queue = child_task->next_queue;
+ child_task->next_queue->prev_queue = child_task->prev_queue;
+ if (team->task_queue == child_task)
+ {
+ if (child_task->next_queue != child_task)
+ team->task_queue = child_task->next_queue;
+ else
+ team->task_queue = NULL;
+ }
+ child_task->kind = GOMP_TASK_TIED;
+ team->task_running_count++;
+ if (team->task_count == team->task_running_count)
+ gomp_team_barrier_clear_task_pending (&team->barrier);
+ }
+ else
+ /* All tasks we are waiting for are already running
+ in other threads. Wait for them. */
+ task->in_taskwait = true;
+ gomp_mutex_unlock (&team->task_lock);
+ if (to_free)
+ {
+ gomp_finish_task (to_free);
+ free (to_free);
+ to_free = NULL;
+ }
+ if (child_task)
+ {
+ thr->task = child_task;
+ child_task->fn (child_task->fn_data);
+ thr->task = task;
+ }
+ else
+ {
+ gomp_sem_wait (&task->taskwait_sem);
+ task->in_taskwait = false;
+ return;
+ }
+ gomp_mutex_lock (&team->task_lock);
+ if (child_task)
+ {
+ child_task->prev_child->next_child = child_task->next_child;
+ child_task->next_child->prev_child = child_task->prev_child;
+ if (task->children == child_task)
+ {
+ if (child_task->next_child != child_task)
+ task->children = child_task->next_child;
+ else
+ task->children = NULL;
+ }
+ gomp_clear_parent (child_task->children);
+ to_free = child_task;
+ child_task = NULL;
+ team->task_count--;
+ team->task_running_count--;
+ }
+ }
+}