diff options
Diffstat (limited to 'libgomp/task.c')
| -rw-r--r-- | libgomp/task.c | 364 |
1 files changed, 364 insertions, 0 deletions
diff --git a/libgomp/task.c b/libgomp/task.c new file mode 100644 index 000000000..95f163d53 --- /dev/null +++ b/libgomp/task.c @@ -0,0 +1,364 @@ +/* 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--; + } + } +} |