/* Copyright (C) 2007, 2008, 2009, 2011 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->final_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) { 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 || (thr->task && thr->task->final_task) || team->task_count > 64 * team->nthreads) { struct gomp_task task; 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; 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 (team != NULL) { gomp_mutex_lock (&team->task_lock); if (task.children != NULL) 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; task->final_task = (flags & 2) >> 1; 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); 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; if (task == NULL || team == 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--; } } } /* Called when encountering a taskyield directive. */ void GOMP_taskyield (void) { /* Nothing at the moment. */ } int omp_in_final (void) { struct gomp_thread *thr = gomp_thread (); return thr->task && thr->task->final_task; } ialias (omp_in_final)