2 * Copyright (c) 2000 Doug Rabson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/systm.h>
33 #include <sys/interrupt.h>
34 #include <sys/kernel.h>
35 #include <sys/kthread.h>
36 #include <sys/limits.h>
38 #include <sys/malloc.h>
39 #include <sys/mutex.h>
41 #include <sys/sched.h>
42 #include <sys/taskqueue.h>
43 #include <sys/unistd.h>
44 #include <machine/stdarg.h>
46 static MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues");
47 static void *taskqueue_giant_ih;
48 static void *taskqueue_ih;
50 struct taskqueue_busy {
51 struct task *tb_running;
52 TAILQ_ENTRY(taskqueue_busy) tb_link;
56 STAILQ_HEAD(, task) tq_queue;
57 taskqueue_enqueue_fn tq_enqueue;
59 TAILQ_HEAD(, taskqueue_busy) tq_active;
61 struct thread **tq_threads;
66 taskqueue_callback_fn tq_callbacks[TASKQUEUE_NUM_CALLBACKS];
67 void *tq_cb_contexts[TASKQUEUE_NUM_CALLBACKS];
70 #define TQ_FLAGS_ACTIVE (1 << 0)
71 #define TQ_FLAGS_BLOCKED (1 << 1)
72 #define TQ_FLAGS_PENDING (1 << 2)
74 #define DT_CALLOUT_ARMED (1 << 0)
79 mtx_lock_spin(&(tq)->tq_mutex); \
81 mtx_lock(&(tq)->tq_mutex); \
83 #define TQ_ASSERT_LOCKED(tq) mtx_assert(&(tq)->tq_mutex, MA_OWNED)
85 #define TQ_UNLOCK(tq) \
88 mtx_unlock_spin(&(tq)->tq_mutex); \
90 mtx_unlock(&(tq)->tq_mutex); \
92 #define TQ_ASSERT_UNLOCKED(tq) mtx_assert(&(tq)->tq_mutex, MA_NOTOWNED)
95 _timeout_task_init(struct taskqueue *queue, struct timeout_task *timeout_task,
96 int priority, task_fn_t func, void *context)
99 TASK_INIT(&timeout_task->t, priority, func, context);
100 callout_init_mtx(&timeout_task->c, &queue->tq_mutex, 0);
101 timeout_task->q = queue;
106 TQ_SLEEP(struct taskqueue *tq, void *p, struct mtx *m, int pri, const char *wm,
110 return (msleep_spin(p, m, wm, t));
111 return (msleep(p, m, pri, wm, t));
114 static struct taskqueue *
115 _taskqueue_create(const char *name __unused, int mflags,
116 taskqueue_enqueue_fn enqueue, void *context,
117 int mtxflags, const char *mtxname)
119 struct taskqueue *queue;
121 queue = malloc(sizeof(struct taskqueue), M_TASKQUEUE, mflags | M_ZERO);
125 STAILQ_INIT(&queue->tq_queue);
126 TAILQ_INIT(&queue->tq_active);
127 queue->tq_enqueue = enqueue;
128 queue->tq_context = context;
129 queue->tq_spin = (mtxflags & MTX_SPIN) != 0;
130 queue->tq_flags |= TQ_FLAGS_ACTIVE;
131 mtx_init(&queue->tq_mutex, mtxname, NULL, mtxflags);
137 taskqueue_create(const char *name, int mflags,
138 taskqueue_enqueue_fn enqueue, void *context)
140 return _taskqueue_create(name, mflags, enqueue, context,
141 MTX_DEF, "taskqueue");
145 taskqueue_set_callback(struct taskqueue *queue,
146 enum taskqueue_callback_type cb_type, taskqueue_callback_fn callback,
150 KASSERT(((cb_type >= TASKQUEUE_CALLBACK_TYPE_MIN) &&
151 (cb_type <= TASKQUEUE_CALLBACK_TYPE_MAX)),
152 ("Callback type %d not valid, must be %d-%d", cb_type,
153 TASKQUEUE_CALLBACK_TYPE_MIN, TASKQUEUE_CALLBACK_TYPE_MAX));
154 KASSERT((queue->tq_callbacks[cb_type] == NULL),
155 ("Re-initialization of taskqueue callback?"));
157 queue->tq_callbacks[cb_type] = callback;
158 queue->tq_cb_contexts[cb_type] = context;
162 * Signal a taskqueue thread to terminate.
165 taskqueue_terminate(struct thread **pp, struct taskqueue *tq)
168 while (tq->tq_tcount > 0 || tq->tq_callouts > 0) {
170 TQ_SLEEP(tq, pp, &tq->tq_mutex, PWAIT, "taskqueue_destroy", 0);
175 taskqueue_free(struct taskqueue *queue)
179 queue->tq_flags &= ~TQ_FLAGS_ACTIVE;
180 taskqueue_terminate(queue->tq_threads, queue);
181 KASSERT(TAILQ_EMPTY(&queue->tq_active), ("Tasks still running?"));
182 KASSERT(queue->tq_callouts == 0, ("Armed timeout tasks"));
183 mtx_destroy(&queue->tq_mutex);
184 free(queue->tq_threads, M_TASKQUEUE);
185 free(queue, M_TASKQUEUE);
189 taskqueue_enqueue_locked(struct taskqueue *queue, struct task *task)
195 * Count multiple enqueues.
197 if (task->ta_pending) {
198 if (task->ta_pending < USHRT_MAX)
204 * Optimise the case when all tasks have the same priority.
206 prev = STAILQ_LAST(&queue->tq_queue, task, ta_link);
207 if (!prev || prev->ta_priority >= task->ta_priority) {
208 STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link);
211 for (ins = STAILQ_FIRST(&queue->tq_queue); ins;
212 prev = ins, ins = STAILQ_NEXT(ins, ta_link))
213 if (ins->ta_priority < task->ta_priority)
217 STAILQ_INSERT_AFTER(&queue->tq_queue, prev, task, ta_link);
219 STAILQ_INSERT_HEAD(&queue->tq_queue, task, ta_link);
222 task->ta_pending = 1;
223 if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0)
224 queue->tq_enqueue(queue->tq_context);
226 queue->tq_flags |= TQ_FLAGS_PENDING;
231 taskqueue_enqueue(struct taskqueue *queue, struct task *task)
236 res = taskqueue_enqueue_locked(queue, task);
243 taskqueue_timeout_func(void *arg)
245 struct taskqueue *queue;
246 struct timeout_task *timeout_task;
249 queue = timeout_task->q;
250 KASSERT((timeout_task->f & DT_CALLOUT_ARMED) != 0, ("Stray timeout"));
251 timeout_task->f &= ~DT_CALLOUT_ARMED;
252 queue->tq_callouts--;
253 taskqueue_enqueue_locked(timeout_task->q, &timeout_task->t);
257 taskqueue_enqueue_timeout(struct taskqueue *queue,
258 struct timeout_task *timeout_task, int ticks)
263 KASSERT(timeout_task->q == NULL || timeout_task->q == queue,
265 KASSERT(!queue->tq_spin, ("Timeout for spin-queue"));
266 timeout_task->q = queue;
267 res = timeout_task->t.ta_pending;
269 taskqueue_enqueue_locked(queue, &timeout_task->t);
271 if ((timeout_task->f & DT_CALLOUT_ARMED) != 0) {
274 queue->tq_callouts++;
275 timeout_task->f |= DT_CALLOUT_ARMED;
277 ticks = -ticks; /* Ignore overflow. */
280 callout_reset(&timeout_task->c, ticks,
281 taskqueue_timeout_func, timeout_task);
289 taskqueue_block(struct taskqueue *queue)
293 queue->tq_flags |= TQ_FLAGS_BLOCKED;
298 taskqueue_unblock(struct taskqueue *queue)
302 queue->tq_flags &= ~TQ_FLAGS_BLOCKED;
303 if (queue->tq_flags & TQ_FLAGS_PENDING) {
304 queue->tq_flags &= ~TQ_FLAGS_PENDING;
305 queue->tq_enqueue(queue->tq_context);
311 taskqueue_run_locked(struct taskqueue *queue)
313 struct taskqueue_busy tb;
317 TQ_ASSERT_LOCKED(queue);
318 tb.tb_running = NULL;
319 TAILQ_INSERT_TAIL(&queue->tq_active, &tb, tb_link);
321 while (STAILQ_FIRST(&queue->tq_queue)) {
323 * Carefully remove the first task from the queue and
324 * zero its pending count.
326 task = STAILQ_FIRST(&queue->tq_queue);
327 STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link);
328 pending = task->ta_pending;
329 task->ta_pending = 0;
330 tb.tb_running = task;
333 task->ta_func(task->ta_context, pending);
336 tb.tb_running = NULL;
339 TAILQ_REMOVE(&queue->tq_active, &tb, tb_link);
343 taskqueue_run(struct taskqueue *queue)
347 taskqueue_run_locked(queue);
352 task_is_running(struct taskqueue *queue, struct task *task)
354 struct taskqueue_busy *tb;
356 TQ_ASSERT_LOCKED(queue);
357 TAILQ_FOREACH(tb, &queue->tq_active, tb_link) {
358 if (tb->tb_running == task)
365 taskqueue_cancel_locked(struct taskqueue *queue, struct task *task,
369 if (task->ta_pending > 0)
370 STAILQ_REMOVE(&queue->tq_queue, task, task, ta_link);
372 *pendp = task->ta_pending;
373 task->ta_pending = 0;
374 return (task_is_running(queue, task) ? EBUSY : 0);
378 taskqueue_cancel(struct taskqueue *queue, struct task *task, u_int *pendp)
383 error = taskqueue_cancel_locked(queue, task, pendp);
390 taskqueue_cancel_timeout(struct taskqueue *queue,
391 struct timeout_task *timeout_task, u_int *pendp)
393 u_int pending, pending1;
397 pending = !!callout_stop(&timeout_task->c);
398 error = taskqueue_cancel_locked(queue, &timeout_task->t, &pending1);
399 if ((timeout_task->f & DT_CALLOUT_ARMED) != 0) {
400 timeout_task->f &= ~DT_CALLOUT_ARMED;
401 queue->tq_callouts--;
406 *pendp = pending + pending1;
411 taskqueue_drain(struct taskqueue *queue, struct task *task)
415 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
418 while (task->ta_pending != 0 || task_is_running(queue, task))
419 TQ_SLEEP(queue, task, &queue->tq_mutex, PWAIT, "-", 0);
424 taskqueue_drain_timeout(struct taskqueue *queue,
425 struct timeout_task *timeout_task)
428 callout_drain(&timeout_task->c);
429 taskqueue_drain(queue, &timeout_task->t);
433 taskqueue_swi_enqueue(void *context)
435 swi_sched(taskqueue_ih, 0);
439 taskqueue_swi_run(void *dummy)
441 taskqueue_run(taskqueue_swi);
445 taskqueue_swi_giant_enqueue(void *context)
447 swi_sched(taskqueue_giant_ih, 0);
451 taskqueue_swi_giant_run(void *dummy)
453 taskqueue_run(taskqueue_swi_giant);
457 taskqueue_start_threads(struct taskqueue **tqp, int count, int pri,
458 const char *name, ...)
462 struct taskqueue *tq;
464 char ktname[MAXCOMLEN + 1];
472 vsnprintf(ktname, sizeof(ktname), name, ap);
475 tq->tq_threads = malloc(sizeof(struct thread *) * count, M_TASKQUEUE,
477 if (tq->tq_threads == NULL) {
478 printf("%s: no memory for %s threads\n", __func__, ktname);
482 for (i = 0; i < count; i++) {
484 error = kthread_add(taskqueue_thread_loop, tqp, NULL,
485 &tq->tq_threads[i], RFSTOPPED, 0, "%s", ktname);
487 error = kthread_add(taskqueue_thread_loop, tqp, NULL,
488 &tq->tq_threads[i], RFSTOPPED, 0,
491 /* should be ok to continue, taskqueue_free will dtrt */
492 printf("%s: kthread_add(%s): error %d", __func__,
494 tq->tq_threads[i] = NULL; /* paranoid */
498 for (i = 0; i < count; i++) {
499 if (tq->tq_threads[i] == NULL)
501 td = tq->tq_threads[i];
504 sched_add(td, SRQ_BORING);
512 taskqueue_run_callback(struct taskqueue *tq,
513 enum taskqueue_callback_type cb_type)
515 taskqueue_callback_fn tq_callback;
517 TQ_ASSERT_UNLOCKED(tq);
518 tq_callback = tq->tq_callbacks[cb_type];
519 if (tq_callback != NULL)
520 tq_callback(tq->tq_cb_contexts[cb_type]);
524 taskqueue_thread_loop(void *arg)
526 struct taskqueue **tqp, *tq;
530 taskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_INIT);
532 while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) {
533 taskqueue_run_locked(tq);
535 * Because taskqueue_run() can drop tq_mutex, we need to
536 * check if the TQ_FLAGS_ACTIVE flag wasn't removed in the
537 * meantime, which means we missed a wakeup.
539 if ((tq->tq_flags & TQ_FLAGS_ACTIVE) == 0)
541 TQ_SLEEP(tq, tq, &tq->tq_mutex, 0, "-", 0);
543 taskqueue_run_locked(tq);
546 * This thread is on its way out, so just drop the lock temporarily
547 * in order to call the shutdown callback. This allows the callback
548 * to look at the taskqueue, even just before it dies.
551 taskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_SHUTDOWN);
554 /* rendezvous with thread that asked us to terminate */
556 wakeup_one(tq->tq_threads);
562 taskqueue_thread_enqueue(void *context)
564 struct taskqueue **tqp, *tq;
569 TQ_ASSERT_LOCKED(tq);
573 TASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, NULL,
574 swi_add(NULL, "task queue", taskqueue_swi_run, NULL, SWI_TQ,
575 INTR_MPSAFE, &taskqueue_ih));
577 TASKQUEUE_DEFINE(swi_giant, taskqueue_swi_giant_enqueue, NULL,
578 swi_add(NULL, "Giant taskq", taskqueue_swi_giant_run,
579 NULL, SWI_TQ_GIANT, 0, &taskqueue_giant_ih));
581 TASKQUEUE_DEFINE_THREAD(thread);
584 taskqueue_create_fast(const char *name, int mflags,
585 taskqueue_enqueue_fn enqueue, void *context)
587 return _taskqueue_create(name, mflags, enqueue, context,
588 MTX_SPIN, "fast_taskqueue");
591 /* NB: for backwards compatibility */
593 taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task)
595 return taskqueue_enqueue(queue, task);
598 static void *taskqueue_fast_ih;
601 taskqueue_fast_enqueue(void *context)
603 swi_sched(taskqueue_fast_ih, 0);
607 taskqueue_fast_run(void *dummy)
609 taskqueue_run(taskqueue_fast);
612 TASKQUEUE_FAST_DEFINE(fast, taskqueue_fast_enqueue, NULL,
613 swi_add(NULL, "fast taskq", taskqueue_fast_run, NULL,
614 SWI_TQ_FAST, INTR_MPSAFE, &taskqueue_fast_ih));
617 taskqueue_member(struct taskqueue *queue, struct thread *td)
621 for (i = 0, j = 0; ; i++) {
622 if (queue->tq_threads[i] == NULL)
624 if (queue->tq_threads[i] == td) {
628 if (++j >= queue->tq_tcount)