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>
37 #include <sys/malloc.h>
38 #include <sys/mutex.h>
40 #include <sys/sched.h>
41 #include <sys/taskqueue.h>
42 #include <sys/unistd.h>
43 #include <machine/stdarg.h>
45 static MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues");
46 static void *taskqueue_giant_ih;
47 static void *taskqueue_ih;
50 STAILQ_HEAD(, task) tq_queue;
52 taskqueue_enqueue_fn tq_enqueue;
54 struct task *tq_running;
56 struct thread **tq_threads;
62 #define TQ_FLAGS_ACTIVE (1 << 0)
63 #define TQ_FLAGS_BLOCKED (1 << 1)
64 #define TQ_FLAGS_PENDING (1 << 2)
67 TQ_LOCK(struct taskqueue *tq)
70 mtx_lock_spin(&tq->tq_mutex);
72 mtx_lock(&tq->tq_mutex);
76 TQ_UNLOCK(struct taskqueue *tq)
79 mtx_unlock_spin(&tq->tq_mutex);
81 mtx_unlock(&tq->tq_mutex);
85 TQ_SLEEP(struct taskqueue *tq, void *p, struct mtx *m, int pri, const char *wm,
89 return (msleep_spin(p, m, wm, t));
90 return (msleep(p, m, pri, wm, t));
93 static struct taskqueue *
94 _taskqueue_create(const char *name, int mflags,
95 taskqueue_enqueue_fn enqueue, void *context,
96 int mtxflags, const char *mtxname)
98 struct taskqueue *queue;
100 queue = malloc(sizeof(struct taskqueue), M_TASKQUEUE, mflags | M_ZERO);
104 STAILQ_INIT(&queue->tq_queue);
105 queue->tq_name = name;
106 queue->tq_enqueue = enqueue;
107 queue->tq_context = context;
108 queue->tq_spin = (mtxflags & MTX_SPIN) != 0;
109 queue->tq_flags |= TQ_FLAGS_ACTIVE;
110 mtx_init(&queue->tq_mutex, mtxname, NULL, mtxflags);
116 taskqueue_create(const char *name, int mflags,
117 taskqueue_enqueue_fn enqueue, void *context)
119 return _taskqueue_create(name, mflags, enqueue, context,
120 MTX_DEF, "taskqueue");
124 * Signal a taskqueue thread to terminate.
127 taskqueue_terminate(struct thread **pp, struct taskqueue *tq)
130 while (tq->tq_tcount > 0) {
132 TQ_SLEEP(tq, pp, &tq->tq_mutex, PWAIT, "taskqueue_destroy", 0);
137 taskqueue_free(struct taskqueue *queue)
141 queue->tq_flags &= ~TQ_FLAGS_ACTIVE;
142 taskqueue_run(queue);
143 taskqueue_terminate(queue->tq_threads, queue);
144 mtx_destroy(&queue->tq_mutex);
145 free(queue->tq_threads, M_TASKQUEUE);
146 free(queue, M_TASKQUEUE);
150 taskqueue_enqueue(struct taskqueue *queue, struct task *task)
158 * Count multiple enqueues.
160 if (task->ta_pending) {
167 * Optimise the case when all tasks have the same priority.
169 prev = STAILQ_LAST(&queue->tq_queue, task, ta_link);
170 if (!prev || prev->ta_priority >= task->ta_priority) {
171 STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link);
174 for (ins = STAILQ_FIRST(&queue->tq_queue); ins;
175 prev = ins, ins = STAILQ_NEXT(ins, ta_link))
176 if (ins->ta_priority < task->ta_priority)
180 STAILQ_INSERT_AFTER(&queue->tq_queue, prev, task, ta_link);
182 STAILQ_INSERT_HEAD(&queue->tq_queue, task, ta_link);
185 task->ta_pending = 1;
186 if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0)
187 queue->tq_enqueue(queue->tq_context);
189 queue->tq_flags |= TQ_FLAGS_PENDING;
197 taskqueue_block(struct taskqueue *queue)
201 queue->tq_flags |= TQ_FLAGS_BLOCKED;
206 taskqueue_unblock(struct taskqueue *queue)
210 queue->tq_flags &= ~TQ_FLAGS_BLOCKED;
211 if (queue->tq_flags & TQ_FLAGS_PENDING) {
212 queue->tq_flags &= ~TQ_FLAGS_PENDING;
213 queue->tq_enqueue(queue->tq_context);
219 taskqueue_run(struct taskqueue *queue)
224 owned = mtx_owned(&queue->tq_mutex);
227 while (STAILQ_FIRST(&queue->tq_queue)) {
229 * Carefully remove the first task from the queue and
230 * zero its pending count.
232 task = STAILQ_FIRST(&queue->tq_queue);
233 STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link);
234 pending = task->ta_pending;
235 task->ta_pending = 0;
236 queue->tq_running = task;
239 task->ta_func(task->ta_context, pending);
242 queue->tq_running = NULL;
247 * For compatibility, unlock on return if the queue was not locked
248 * on entry, although this opens a race window.
255 taskqueue_drain(struct taskqueue *queue, struct task *task)
257 if (queue->tq_spin) { /* XXX */
258 mtx_lock_spin(&queue->tq_mutex);
259 while (task->ta_pending != 0 || task == queue->tq_running)
260 msleep_spin(task, &queue->tq_mutex, "-", 0);
261 mtx_unlock_spin(&queue->tq_mutex);
263 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
265 mtx_lock(&queue->tq_mutex);
266 while (task->ta_pending != 0 || task == queue->tq_running)
267 msleep(task, &queue->tq_mutex, PWAIT, "-", 0);
268 mtx_unlock(&queue->tq_mutex);
273 taskqueue_swi_enqueue(void *context)
275 swi_sched(taskqueue_ih, 0);
279 taskqueue_swi_run(void *dummy)
281 taskqueue_run(taskqueue_swi);
285 taskqueue_swi_giant_enqueue(void *context)
287 swi_sched(taskqueue_giant_ih, 0);
291 taskqueue_swi_giant_run(void *dummy)
293 taskqueue_run(taskqueue_swi_giant);
297 taskqueue_start_threads(struct taskqueue **tqp, int count, int pri,
298 const char *name, ...)
302 struct taskqueue *tq;
304 char ktname[MAXCOMLEN];
312 vsnprintf(ktname, MAXCOMLEN, name, ap);
315 tq->tq_threads = malloc(sizeof(struct thread *) * count, M_TASKQUEUE,
317 if (tq->tq_threads == NULL) {
318 printf("%s: no memory for %s threads\n", __func__, ktname);
322 for (i = 0; i < count; i++) {
324 error = kthread_add(taskqueue_thread_loop, tqp, NULL,
325 &tq->tq_threads[i], RFSTOPPED, 0, ktname);
327 error = kthread_add(taskqueue_thread_loop, tqp, NULL,
328 &tq->tq_threads[i], RFSTOPPED, 0,
331 /* should be ok to continue, taskqueue_free will dtrt */
332 printf("%s: kthread_add(%s): error %d", __func__,
334 tq->tq_threads[i] = NULL; /* paranoid */
338 for (i = 0; i < count; i++) {
339 if (tq->tq_threads[i] == NULL)
341 td = tq->tq_threads[i];
344 sched_add(td, SRQ_BORING);
352 taskqueue_thread_loop(void *arg)
354 struct taskqueue **tqp, *tq;
359 while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) {
362 * Because taskqueue_run() can drop tq_mutex, we need to
363 * check if the TQ_FLAGS_ACTIVE flag wasn't removed in the
364 * meantime, which means we missed a wakeup.
366 if ((tq->tq_flags & TQ_FLAGS_ACTIVE) == 0)
368 TQ_SLEEP(tq, tq, &tq->tq_mutex, 0, "-", 0);
371 /* rendezvous with thread that asked us to terminate */
373 wakeup_one(tq->tq_threads);
379 taskqueue_thread_enqueue(void *context)
381 struct taskqueue **tqp, *tq;
386 mtx_assert(&tq->tq_mutex, MA_OWNED);
390 TASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, NULL,
391 swi_add(NULL, "task queue", taskqueue_swi_run, NULL, SWI_TQ,
392 INTR_MPSAFE, &taskqueue_ih));
394 TASKQUEUE_DEFINE(swi_giant, taskqueue_swi_giant_enqueue, NULL,
395 swi_add(NULL, "Giant taskq", taskqueue_swi_giant_run,
396 NULL, SWI_TQ_GIANT, 0, &taskqueue_giant_ih));
398 TASKQUEUE_DEFINE_THREAD(thread);
401 taskqueue_create_fast(const char *name, int mflags,
402 taskqueue_enqueue_fn enqueue, void *context)
404 return _taskqueue_create(name, mflags, enqueue, context,
405 MTX_SPIN, "fast_taskqueue");
408 /* NB: for backwards compatibility */
410 taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task)
412 return taskqueue_enqueue(queue, task);
415 static void *taskqueue_fast_ih;
418 taskqueue_fast_enqueue(void *context)
420 swi_sched(taskqueue_fast_ih, 0);
424 taskqueue_fast_run(void *dummy)
426 taskqueue_run(taskqueue_fast);
429 TASKQUEUE_FAST_DEFINE(fast, taskqueue_fast_enqueue, NULL,
430 swi_add(NULL, "Fast task queue", taskqueue_fast_run, NULL,
431 SWI_TQ_FAST, INTR_MPSAFE, &taskqueue_fast_ih));
434 taskqueue_member(struct taskqueue *queue, struct thread *td)
439 for (i = 0, j = 0; ; i++) {
440 if (queue->tq_threads[i] == NULL)
442 if (queue->tq_threads[i] == td) {
446 if (++j >= queue->tq_tcount)