Retro68/gcc/libgomp/task.c
2014-09-21 19:33:12 +02:00

1000 lines
27 KiB
C

/* Copyright (C) 2007-2014 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>
typedef struct gomp_task_depend_entry *hash_entry_type;
static inline void *
htab_alloc (size_t size)
{
return gomp_malloc (size);
}
static inline void
htab_free (void *ptr)
{
free (ptr);
}
#include "hashtab.h"
static inline hashval_t
htab_hash (hash_entry_type element)
{
return hash_pointer (element->addr);
}
static inline bool
htab_eq (hash_entry_type x, hash_entry_type y)
{
return x->addr == y->addr;
}
/* 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->final_task = false;
task->copy_ctors_done = false;
task->children = NULL;
task->taskgroup = NULL;
task->dependers = NULL;
task->depend_hash = NULL;
task->depend_count = 0;
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,
void **depend)
{
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 parallel or taskgroup has been cancelled, don't start new tasks. */
if (team
&& (gomp_team_barrier_cancelled (&team->barrier)
|| (thr->task->taskgroup && thr->task->taskgroup->cancelled)))
return;
if (!if_clause || team == NULL
|| (thr->task && thr->task->final_task)
|| team->task_count > 64 * team->nthreads)
{
struct gomp_task task;
/* If there are depend clauses and earlier deferred sibling tasks
with depend clauses, check if there isn't a dependency. If there
is, fall through to the deferred task handling, as we can't
schedule such tasks right away. There is no need to handle
depend clauses for non-deferred tasks other than this, because
the parent task is suspended until the child task finishes and thus
it can't start further child tasks. */
if ((flags & 8) && thr->task && thr->task->depend_hash)
{
struct gomp_task *parent = thr->task;
struct gomp_task_depend_entry elem, *ent = NULL;
size_t ndepend = (uintptr_t) depend[0];
size_t nout = (uintptr_t) depend[1];
size_t i;
gomp_mutex_lock (&team->task_lock);
for (i = 0; i < ndepend; i++)
{
elem.addr = depend[i + 2];
ent = htab_find (parent->depend_hash, &elem);
for (; ent; ent = ent->next)
if (i >= nout && ent->is_in)
continue;
else
break;
if (ent)
break;
}
gomp_mutex_unlock (&team->task_lock);
if (ent)
goto defer;
}
gomp_init_task (&task, thr->task, gomp_icv (false));
task.kind = GOMP_TASK_IFFALSE;
task.final_task = (thr->task && thr->task->final_task) || (flags & 2);
if (thr->task)
{
task.in_tied_task = thr->task->in_tied_task;
task.taskgroup = thr->task->taskgroup;
}
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);
/* Access to "children" is normally done inside a task_lock
mutex region, but the only way this particular task.children
can be set is if this thread's task work function (fn)
creates children. So since the setter is *this* thread, we
need no barriers here when testing for non-NULL. We can have
task.children set by the current thread then changed by a
child thread, but seeing a stale non-NULL value is not a
problem. Once past the task_lock acquisition, this thread
will see the real value of task.children. */
if (task.children != NULL)
{
gomp_mutex_lock (&team->task_lock);
gomp_clear_parent (task.children);
gomp_mutex_unlock (&team->task_lock);
}
gomp_end_task ();
}
else
{
defer:;
struct gomp_task *task;
struct gomp_task *parent = thr->task;
struct gomp_taskgroup *taskgroup = parent->taskgroup;
char *arg;
bool do_wake;
size_t depend_size = 0;
if (flags & 8)
depend_size = ((uintptr_t) depend[0]
* sizeof (struct gomp_task_depend_entry));
task = gomp_malloc (sizeof (*task) + depend_size
+ arg_size + arg_align - 1);
arg = (char *) (((uintptr_t) (task + 1) + depend_size + 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;
task->taskgroup = taskgroup;
thr->task = task;
if (cpyfn)
{
cpyfn (arg, data);
task->copy_ctors_done = true;
}
else
memcpy (arg, data, arg_size);
thr->task = parent;
task->kind = GOMP_TASK_WAITING;
task->fn = fn;
task->fn_data = arg;
task->final_task = (flags & 2) >> 1;
gomp_mutex_lock (&team->task_lock);
/* If parallel or taskgroup has been cancelled, don't start new
tasks. */
if (__builtin_expect ((gomp_team_barrier_cancelled (&team->barrier)
|| (taskgroup && taskgroup->cancelled))
&& !task->copy_ctors_done, 0))
{
gomp_mutex_unlock (&team->task_lock);
gomp_finish_task (task);
free (task);
return;
}
if (taskgroup)
taskgroup->num_children++;
if (depend_size)
{
size_t ndepend = (uintptr_t) depend[0];
size_t nout = (uintptr_t) depend[1];
size_t i;
hash_entry_type ent;
task->depend_count = ndepend;
task->num_dependees = 0;
if (parent->depend_hash == NULL)
parent->depend_hash
= htab_create (2 * ndepend > 12 ? 2 * ndepend : 12);
for (i = 0; i < ndepend; i++)
{
task->depend[i].addr = depend[2 + i];
task->depend[i].next = NULL;
task->depend[i].prev = NULL;
task->depend[i].task = task;
task->depend[i].is_in = i >= nout;
task->depend[i].redundant = false;
hash_entry_type *slot
= htab_find_slot (&parent->depend_hash, &task->depend[i],
INSERT);
hash_entry_type out = NULL;
if (*slot)
{
/* If multiple depends on the same task are the
same, all but the first one are redundant.
As inout/out come first, if any of them is
inout/out, it will win, which is the right
semantics. */
if ((*slot)->task == task)
{
task->depend[i].redundant = true;
continue;
}
for (ent = *slot; ent; ent = ent->next)
{
/* depend(in:...) doesn't depend on earlier
depend(in:...). */
if (i >= nout && ent->is_in)
continue;
if (!ent->is_in)
out = ent;
struct gomp_task *tsk = ent->task;
if (tsk->dependers == NULL)
{
tsk->dependers
= gomp_malloc (sizeof (struct gomp_dependers_vec)
+ 6 * sizeof (struct gomp_task *));
tsk->dependers->n_elem = 1;
tsk->dependers->allocated = 6;
tsk->dependers->elem[0] = task;
task->num_dependees++;
continue;
}
/* We already have some other dependency on tsk
from earlier depend clause. */
else if (tsk->dependers->n_elem
&& (tsk->dependers->elem[tsk->dependers->n_elem
- 1]
== task))
continue;
else if (tsk->dependers->n_elem
== tsk->dependers->allocated)
{
tsk->dependers->allocated
= tsk->dependers->allocated * 2 + 2;
tsk->dependers
= gomp_realloc (tsk->dependers,
sizeof (struct gomp_dependers_vec)
+ (tsk->dependers->allocated
* sizeof (struct gomp_task *)));
}
tsk->dependers->elem[tsk->dependers->n_elem++] = task;
task->num_dependees++;
}
task->depend[i].next = *slot;
(*slot)->prev = &task->depend[i];
}
*slot = &task->depend[i];
/* There is no need to store more than one depend({,in}out:)
task per address in the hash table chain, because each out
depends on all earlier outs, thus it is enough to record
just the last depend({,in}out:). For depend(in:), we need
to keep all of the previous ones not terminated yet, because
a later depend({,in}out:) might need to depend on all of
them. So, if the new task's clause is depend({,in}out:),
we know there is at most one other depend({,in}out:) clause
in the list (out) and to maintain the invariant we now
need to remove it from the list. */
if (!task->depend[i].is_in && out)
{
if (out->next)
out->next->prev = out->prev;
out->prev->next = out->next;
out->redundant = true;
}
}
if (task->num_dependees)
{
gomp_mutex_unlock (&team->task_lock);
return;
}
}
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 (taskgroup)
{
if (taskgroup->children)
{
task->next_taskgroup = taskgroup->children;
task->prev_taskgroup = taskgroup->children->prev_taskgroup;
task->next_taskgroup->prev_taskgroup = task;
task->prev_taskgroup->next_taskgroup = task;
}
else
{
task->next_taskgroup = task;
task->prev_taskgroup = task;
}
taskgroup->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;
++team->task_queued_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);
}
}
static inline bool
gomp_task_run_pre (struct gomp_task *child_task, struct gomp_task *parent,
struct gomp_taskgroup *taskgroup, struct gomp_team *team)
{
if (parent && parent->children == child_task)
parent->children = child_task->next_child;
if (taskgroup && taskgroup->children == child_task)
taskgroup->children = child_task->next_taskgroup;
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;
if (--team->task_queued_count == 0)
gomp_team_barrier_clear_task_pending (&team->barrier);
if ((gomp_team_barrier_cancelled (&team->barrier)
|| (taskgroup && taskgroup->cancelled))
&& !child_task->copy_ctors_done)
return true;
return false;
}
static void
gomp_task_run_post_handle_depend_hash (struct gomp_task *child_task)
{
struct gomp_task *parent = child_task->parent;
size_t i;
for (i = 0; i < child_task->depend_count; i++)
if (!child_task->depend[i].redundant)
{
if (child_task->depend[i].next)
child_task->depend[i].next->prev = child_task->depend[i].prev;
if (child_task->depend[i].prev)
child_task->depend[i].prev->next = child_task->depend[i].next;
else
{
hash_entry_type *slot
= htab_find_slot (&parent->depend_hash, &child_task->depend[i],
NO_INSERT);
if (*slot != &child_task->depend[i])
abort ();
if (child_task->depend[i].next)
*slot = child_task->depend[i].next;
else
htab_clear_slot (parent->depend_hash, slot);
}
}
}
static size_t
gomp_task_run_post_handle_dependers (struct gomp_task *child_task,
struct gomp_team *team)
{
struct gomp_task *parent = child_task->parent;
size_t i, count = child_task->dependers->n_elem, ret = 0;
for (i = 0; i < count; i++)
{
struct gomp_task *task = child_task->dependers->elem[i];
if (--task->num_dependees != 0)
continue;
struct gomp_taskgroup *taskgroup = task->taskgroup;
if (parent)
{
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 (parent->in_taskwait)
{
parent->in_taskwait = false;
gomp_sem_post (&parent->taskwait_sem);
}
}
if (taskgroup)
{
if (taskgroup->children)
{
task->next_taskgroup = taskgroup->children;
task->prev_taskgroup = taskgroup->children->prev_taskgroup;
task->next_taskgroup->prev_taskgroup = task;
task->prev_taskgroup->next_taskgroup = task;
}
else
{
task->next_taskgroup = task;
task->prev_taskgroup = task;
}
taskgroup->children = task;
if (taskgroup->in_taskgroup_wait)
{
taskgroup->in_taskgroup_wait = false;
gomp_sem_post (&taskgroup->taskgroup_sem);
}
}
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;
++team->task_queued_count;
++ret;
}
free (child_task->dependers);
child_task->dependers = NULL;
if (ret > 1)
gomp_team_barrier_set_task_pending (&team->barrier);
return ret;
}
static inline size_t
gomp_task_run_post_handle_depend (struct gomp_task *child_task,
struct gomp_team *team)
{
if (child_task->depend_count == 0)
return 0;
/* If parent is gone already, the hash table is freed and nothing
will use the hash table anymore, no need to remove anything from it. */
if (child_task->parent != NULL)
gomp_task_run_post_handle_depend_hash (child_task);
if (child_task->dependers == NULL)
return 0;
return gomp_task_run_post_handle_dependers (child_task, team);
}
static inline void
gomp_task_run_post_remove_parent (struct gomp_task *child_task)
{
struct gomp_task *parent = child_task->parent;
if (parent == NULL)
return;
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)
return;
if (child_task->next_child != child_task)
parent->children = child_task->next_child;
else
{
/* We access task->children in GOMP_taskwait
outside of the task lock mutex region, so
need a release barrier here to ensure memory
written by child_task->fn above is flushed
before the NULL is written. */
__atomic_store_n (&parent->children, NULL, MEMMODEL_RELEASE);
if (parent->in_taskwait)
{
parent->in_taskwait = false;
gomp_sem_post (&parent->taskwait_sem);
}
}
}
static inline void
gomp_task_run_post_remove_taskgroup (struct gomp_task *child_task)
{
struct gomp_taskgroup *taskgroup = child_task->taskgroup;
if (taskgroup == NULL)
return;
child_task->prev_taskgroup->next_taskgroup = child_task->next_taskgroup;
child_task->next_taskgroup->prev_taskgroup = child_task->prev_taskgroup;
if (taskgroup->num_children > 1)
--taskgroup->num_children;
else
{
/* We access taskgroup->num_children in GOMP_taskgroup_end
outside of the task lock mutex region, so
need a release barrier here to ensure memory
written by child_task->fn above is flushed
before the NULL is written. */
__atomic_store_n (&taskgroup->num_children, 0, MEMMODEL_RELEASE);
}
if (taskgroup->children != child_task)
return;
if (child_task->next_taskgroup != child_task)
taskgroup->children = child_task->next_taskgroup;
else
{
taskgroup->children = NULL;
if (taskgroup->in_taskgroup_wait)
{
taskgroup->in_taskgroup_wait = false;
gomp_sem_post (&taskgroup->taskgroup_sem);
}
}
}
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;
int do_wake = 0;
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)
{
bool cancelled = false;
if (team->task_queue != NULL)
{
child_task = team->task_queue;
cancelled = gomp_task_run_pre (child_task, child_task->parent,
child_task->taskgroup, team);
if (__builtin_expect (cancelled, 0))
{
if (to_free)
{
gomp_finish_task (to_free);
free (to_free);
to_free = NULL;
}
goto finish_cancelled;
}
team->task_running_count++;
child_task->in_tied_task = true;
}
gomp_mutex_unlock (&team->task_lock);
if (do_wake)
{
gomp_team_barrier_wake (&team->barrier, do_wake);
do_wake = 0;
}
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)
{
finish_cancelled:;
size_t new_tasks
= gomp_task_run_post_handle_depend (child_task, team);
gomp_task_run_post_remove_parent (child_task);
gomp_clear_parent (child_task->children);
gomp_task_run_post_remove_taskgroup (child_task);
to_free = child_task;
child_task = NULL;
if (!cancelled)
team->task_running_count--;
if (new_tasks > 1)
{
do_wake = team->nthreads - team->task_running_count;
if (do_wake > new_tasks)
do_wake = new_tasks;
}
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);
gomp_mutex_lock (&team->task_lock);
}
}
}
}
/* 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;
int do_wake = 0;
/* The acquire barrier on load of task->children here synchronizes
with the write of a NULL in gomp_task_run_post_remove_parent. It is
not necessary that we synchronize with other non-NULL writes at
this point, but we must ensure that all writes to memory by a
child thread task work function are seen before we exit from
GOMP_taskwait. */
if (task == NULL
|| __atomic_load_n (&task->children, MEMMODEL_ACQUIRE) == NULL)
return;
gomp_mutex_lock (&team->task_lock);
while (1)
{
bool cancelled = false;
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;
cancelled
= gomp_task_run_pre (child_task, task, child_task->taskgroup,
team);
if (__builtin_expect (cancelled, 0))
{
if (to_free)
{
gomp_finish_task (to_free);
free (to_free);
to_free = NULL;
}
goto finish_cancelled;
}
}
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 (do_wake)
{
gomp_team_barrier_wake (&team->barrier, do_wake);
do_wake = 0;
}
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);
gomp_mutex_lock (&team->task_lock);
if (child_task)
{
finish_cancelled:;
size_t new_tasks
= gomp_task_run_post_handle_depend (child_task, team);
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);
gomp_task_run_post_remove_taskgroup (child_task);
to_free = child_task;
child_task = NULL;
team->task_count--;
if (new_tasks > 1)
{
do_wake = team->nthreads - team->task_running_count
- !task->in_tied_task;
if (do_wake > new_tasks)
do_wake = new_tasks;
}
}
}
}
/* Called when encountering a taskyield directive. */
void
GOMP_taskyield (void)
{
/* Nothing at the moment. */
}
void
GOMP_taskgroup_start (void)
{
struct gomp_thread *thr = gomp_thread ();
struct gomp_team *team = thr->ts.team;
struct gomp_task *task = thr->task;
struct gomp_taskgroup *taskgroup;
/* If team is NULL, all tasks are executed as
GOMP_TASK_IFFALSE tasks and thus all children tasks of
taskgroup and their descendant tasks will be finished
by the time GOMP_taskgroup_end is called. */
if (team == NULL)
return;
taskgroup = gomp_malloc (sizeof (struct gomp_taskgroup));
taskgroup->prev = task->taskgroup;
taskgroup->children = NULL;
taskgroup->in_taskgroup_wait = false;
taskgroup->cancelled = false;
taskgroup->num_children = 0;
gomp_sem_init (&taskgroup->taskgroup_sem, 0);
task->taskgroup = taskgroup;
}
void
GOMP_taskgroup_end (void)
{
struct gomp_thread *thr = gomp_thread ();
struct gomp_team *team = thr->ts.team;
struct gomp_task *task = thr->task;
struct gomp_taskgroup *taskgroup;
struct gomp_task *child_task = NULL;
struct gomp_task *to_free = NULL;
int do_wake = 0;
if (team == NULL)
return;
taskgroup = task->taskgroup;
/* The acquire barrier on load of taskgroup->num_children here
synchronizes with the write of 0 in gomp_task_run_post_remove_taskgroup.
It is not necessary that we synchronize with other non-0 writes at
this point, but we must ensure that all writes to memory by a
child thread task work function are seen before we exit from
GOMP_taskgroup_end. */
if (__atomic_load_n (&taskgroup->num_children, MEMMODEL_ACQUIRE) == 0)
goto finish;
gomp_mutex_lock (&team->task_lock);
while (1)
{
bool cancelled = false;
if (taskgroup->children == NULL)
{
if (taskgroup->num_children)
goto do_wait;
gomp_mutex_unlock (&team->task_lock);
if (to_free)
{
gomp_finish_task (to_free);
free (to_free);
}
goto finish;
}
if (taskgroup->children->kind == GOMP_TASK_WAITING)
{
child_task = taskgroup->children;
cancelled
= gomp_task_run_pre (child_task, child_task->parent, taskgroup,
team);
if (__builtin_expect (cancelled, 0))
{
if (to_free)
{
gomp_finish_task (to_free);
free (to_free);
to_free = NULL;
}
goto finish_cancelled;
}
}
else
{
do_wait:
/* All tasks we are waiting for are already running
in other threads. Wait for them. */
taskgroup->in_taskgroup_wait = true;
}
gomp_mutex_unlock (&team->task_lock);
if (do_wake)
{
gomp_team_barrier_wake (&team->barrier, do_wake);
do_wake = 0;
}
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 (&taskgroup->taskgroup_sem);
gomp_mutex_lock (&team->task_lock);
if (child_task)
{
finish_cancelled:;
size_t new_tasks
= gomp_task_run_post_handle_depend (child_task, team);
child_task->prev_taskgroup->next_taskgroup
= child_task->next_taskgroup;
child_task->next_taskgroup->prev_taskgroup
= child_task->prev_taskgroup;
--taskgroup->num_children;
if (taskgroup->children == child_task)
{
if (child_task->next_taskgroup != child_task)
taskgroup->children = child_task->next_taskgroup;
else
taskgroup->children = NULL;
}
gomp_task_run_post_remove_parent (child_task);
gomp_clear_parent (child_task->children);
to_free = child_task;
child_task = NULL;
team->task_count--;
if (new_tasks > 1)
{
do_wake = team->nthreads - team->task_running_count
- !task->in_tied_task;
if (do_wake > new_tasks)
do_wake = new_tasks;
}
}
}
finish:
task->taskgroup = taskgroup->prev;
gomp_sem_destroy (&taskgroup->taskgroup_sem);
free (taskgroup);
}
int
omp_in_final (void)
{
struct gomp_thread *thr = gomp_thread ();
return thr->task && thr->task->final_task;
}
ialias (omp_in_final)