1 /* Copyright (C) 2007, 2008, 2009, 2011 Free Software Foundation, Inc.
2 Contributed by Richard Henderson <rth@redhat.com>.
4 This file is part of the GNU OpenMP Library (libgomp).
6 Libgomp is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
11 Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13 FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 Under Section 7 of GPL version 3, you are granted additional
17 permissions described in the GCC Runtime Library Exception, version
18 3.1, as published by the Free Software Foundation.
20 You should have received a copy of the GNU General Public License and
21 a copy of the GCC Runtime Library Exception along with this program;
22 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 <http://www.gnu.org/licenses/>. */
25 /* This file handles the maintainence of tasks in response to task
26 creation and termination. */
33 /* Create a new task data structure. */
36 gomp_init_task (struct gomp_task *task, struct gomp_task *parent_task,
37 struct gomp_task_icv *prev_icv)
39 task->parent = parent_task;
40 task->icv = *prev_icv;
41 task->kind = GOMP_TASK_IMPLICIT;
42 task->in_taskwait = false;
43 task->in_tied_task = false;
44 task->final_task = false;
45 task->children = NULL;
46 gomp_sem_init (&task->taskwait_sem, 0);
49 /* Clean up a task, after completing it. */
54 struct gomp_thread *thr = gomp_thread ();
55 struct gomp_task *task = thr->task;
57 gomp_finish_task (task);
58 thr->task = task->parent;
62 gomp_clear_parent (struct gomp_task *children)
64 struct gomp_task *task = children;
70 task = task->next_child;
72 while (task != children);
75 /* Called when encountering an explicit task directive. If IF_CLAUSE is
76 false, then we must not delay in executing the task. If UNTIED is true,
77 then the task may be executed by any member of the team. */
80 GOMP_task (void (*fn) (void *), void *data, void (*cpyfn) (void *, void *),
81 long arg_size, long arg_align, bool if_clause, unsigned flags)
83 struct gomp_thread *thr = gomp_thread ();
84 struct gomp_team *team = thr->ts.team;
86 #ifdef HAVE_BROKEN_POSIX_SEMAPHORES
87 /* If pthread_mutex_* is used for omp_*lock*, then each task must be
88 tied to one thread all the time. This means UNTIED tasks must be
89 tied and if CPYFN is non-NULL IF(0) must be forced, as CPYFN
90 might be running on different thread than FN. */
97 if (!if_clause || team == NULL
98 || (thr->task && thr->task->final_task)
99 || team->task_count > 64 * team->nthreads)
101 struct gomp_task task;
103 gomp_init_task (&task, thr->task, gomp_icv (false));
104 task.kind = GOMP_TASK_IFFALSE;
105 task.final_task = (thr->task && thr->task->final_task) || (flags & 2);
107 task.in_tied_task = thr->task->in_tied_task;
109 if (__builtin_expect (cpyfn != NULL, 0))
111 char buf[arg_size + arg_align - 1];
112 char *arg = (char *) (((uintptr_t) buf + arg_align - 1)
113 & ~(uintptr_t) (arg_align - 1));
121 gomp_mutex_lock (&team->task_lock);
122 gomp_clear_parent (task.children);
123 gomp_mutex_unlock (&team->task_lock);
129 struct gomp_task *task;
130 struct gomp_task *parent = thr->task;
134 task = gomp_malloc (sizeof (*task) + arg_size + arg_align - 1);
135 arg = (char *) (((uintptr_t) (task + 1) + arg_align - 1)
136 & ~(uintptr_t) (arg_align - 1));
137 gomp_init_task (task, parent, gomp_icv (false));
138 task->kind = GOMP_TASK_IFFALSE;
139 task->in_tied_task = parent->in_tied_task;
144 memcpy (arg, data, arg_size);
146 task->kind = GOMP_TASK_WAITING;
149 task->in_tied_task = true;
150 task->final_task = (flags & 2) >> 1;
151 gomp_mutex_lock (&team->task_lock);
152 if (parent->children)
154 task->next_child = parent->children;
155 task->prev_child = parent->children->prev_child;
156 task->next_child->prev_child = task;
157 task->prev_child->next_child = task;
161 task->next_child = task;
162 task->prev_child = task;
164 parent->children = task;
165 if (team->task_queue)
167 task->next_queue = team->task_queue;
168 task->prev_queue = team->task_queue->prev_queue;
169 task->next_queue->prev_queue = task;
170 task->prev_queue->next_queue = task;
174 task->next_queue = task;
175 task->prev_queue = task;
176 team->task_queue = task;
179 gomp_team_barrier_set_task_pending (&team->barrier);
180 do_wake = team->task_running_count + !parent->in_tied_task
182 gomp_mutex_unlock (&team->task_lock);
184 gomp_team_barrier_wake (&team->barrier, 1);
189 gomp_barrier_handle_tasks (gomp_barrier_state_t state)
191 struct gomp_thread *thr = gomp_thread ();
192 struct gomp_team *team = thr->ts.team;
193 struct gomp_task *task = thr->task;
194 struct gomp_task *child_task = NULL;
195 struct gomp_task *to_free = NULL;
197 gomp_mutex_lock (&team->task_lock);
198 if (gomp_barrier_last_thread (state))
200 if (team->task_count == 0)
202 gomp_team_barrier_done (&team->barrier, state);
203 gomp_mutex_unlock (&team->task_lock);
204 gomp_team_barrier_wake (&team->barrier, 0);
207 gomp_team_barrier_set_waiting_for_tasks (&team->barrier);
212 if (team->task_queue != NULL)
214 struct gomp_task *parent;
216 child_task = team->task_queue;
217 parent = child_task->parent;
218 if (parent && parent->children == child_task)
219 parent->children = child_task->next_child;
220 child_task->prev_queue->next_queue = child_task->next_queue;
221 child_task->next_queue->prev_queue = child_task->prev_queue;
222 if (child_task->next_queue != child_task)
223 team->task_queue = child_task->next_queue;
225 team->task_queue = NULL;
226 child_task->kind = GOMP_TASK_TIED;
227 team->task_running_count++;
228 if (team->task_count == team->task_running_count)
229 gomp_team_barrier_clear_task_pending (&team->barrier);
231 gomp_mutex_unlock (&team->task_lock);
234 gomp_finish_task (to_free);
240 thr->task = child_task;
241 child_task->fn (child_task->fn_data);
246 gomp_mutex_lock (&team->task_lock);
249 struct gomp_task *parent = child_task->parent;
252 child_task->prev_child->next_child = child_task->next_child;
253 child_task->next_child->prev_child = child_task->prev_child;
254 if (parent->children == child_task)
256 if (child_task->next_child != child_task)
257 parent->children = child_task->next_child;
260 parent->children = NULL;
261 if (parent->in_taskwait)
262 gomp_sem_post (&parent->taskwait_sem);
266 gomp_clear_parent (child_task->children);
267 to_free = child_task;
269 team->task_running_count--;
270 if (--team->task_count == 0
271 && gomp_team_barrier_waiting_for_tasks (&team->barrier))
273 gomp_team_barrier_done (&team->barrier, state);
274 gomp_mutex_unlock (&team->task_lock);
275 gomp_team_barrier_wake (&team->barrier, 0);
276 gomp_mutex_lock (&team->task_lock);
282 /* Called when encountering a taskwait directive. */
287 struct gomp_thread *thr = gomp_thread ();
288 struct gomp_team *team = thr->ts.team;
289 struct gomp_task *task = thr->task;
290 struct gomp_task *child_task = NULL;
291 struct gomp_task *to_free = NULL;
293 if (task == NULL || task->children == NULL)
295 gomp_mutex_lock (&team->task_lock);
298 if (task->children == NULL)
300 gomp_mutex_unlock (&team->task_lock);
303 gomp_finish_task (to_free);
308 if (task->children->kind == GOMP_TASK_WAITING)
310 child_task = task->children;
311 task->children = child_task->next_child;
312 child_task->prev_queue->next_queue = child_task->next_queue;
313 child_task->next_queue->prev_queue = child_task->prev_queue;
314 if (team->task_queue == child_task)
316 if (child_task->next_queue != child_task)
317 team->task_queue = child_task->next_queue;
319 team->task_queue = NULL;
321 child_task->kind = GOMP_TASK_TIED;
322 team->task_running_count++;
323 if (team->task_count == team->task_running_count)
324 gomp_team_barrier_clear_task_pending (&team->barrier);
327 /* All tasks we are waiting for are already running
328 in other threads. Wait for them. */
329 task->in_taskwait = true;
330 gomp_mutex_unlock (&team->task_lock);
333 gomp_finish_task (to_free);
339 thr->task = child_task;
340 child_task->fn (child_task->fn_data);
345 gomp_sem_wait (&task->taskwait_sem);
346 task->in_taskwait = false;
349 gomp_mutex_lock (&team->task_lock);
352 child_task->prev_child->next_child = child_task->next_child;
353 child_task->next_child->prev_child = child_task->prev_child;
354 if (task->children == child_task)
356 if (child_task->next_child != child_task)
357 task->children = child_task->next_child;
359 task->children = NULL;
361 gomp_clear_parent (child_task->children);
362 to_free = child_task;
365 team->task_running_count--;
370 /* Called when encountering a taskyield directive. */
373 GOMP_taskyield (void)
375 /* Nothing at the moment. */
381 struct gomp_thread *thr = gomp_thread ();
382 return thr->task && thr->task->final_task;
385 ialias (omp_in_final)