1 /*- 2 * Copyright (c) 2000 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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. 13 * 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 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/bus.h> 33 #include <sys/kernel.h> 34 #include <sys/kthread.h> 35 #include <sys/libkern.h> 36 #include <sys/limits.h> 37 #include <sys/lock.h> 38 #include <sys/malloc.h> 39 #include <sys/mutex.h> 40 #include <sys/proc.h> 41 #include <sys/smp.h> 42 #include <sys/taskqueue.h> 43 #include <machine/stdarg.h> 44 45 static MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues"); 46 static void *taskqueue_giant_ih; 47 static void *taskqueue_ih; 48 49 struct taskqueue_busy { 50 struct task *tb_running; 51 TAILQ_ENTRY(taskqueue_busy) tb_link; 52 }; 53 54 struct task * const TB_DRAIN_WAITER = (struct task *)0x1; 55 56 struct taskqueue { 57 STAILQ_HEAD(, task) tq_queue; 58 taskqueue_enqueue_fn tq_enqueue; 59 void *tq_context; 60 char *tq_name; 61 TAILQ_HEAD(, taskqueue_busy) tq_active; 62 struct mtx tq_mutex; 63 #ifdef __HAIKU__ 64 sem_id tq_sem; 65 thread_id *tq_threads; 66 thread_id tq_thread_storage; 67 int tq_threadcount; 68 #else 69 struct thread **tq_threads; 70 #endif 71 int tq_tcount; 72 int tq_spin; 73 int tq_flags; 74 int tq_callouts; 75 taskqueue_callback_fn tq_callbacks[TASKQUEUE_NUM_CALLBACKS]; 76 void *tq_cb_contexts[TASKQUEUE_NUM_CALLBACKS]; 77 }; 78 79 #define TQ_FLAGS_ACTIVE (1 << 0) 80 #define TQ_FLAGS_BLOCKED (1 << 1) 81 #define TQ_FLAGS_UNLOCKED_ENQUEUE (1 << 2) 82 83 #define DT_CALLOUT_ARMED (1 << 0) 84 #define DT_DRAIN_IN_PROGRESS (1 << 1) 85 86 #define TQ_LOCK(tq) \ 87 do { \ 88 if ((tq)->tq_spin) \ 89 mtx_lock_spin(&(tq)->tq_mutex); \ 90 else \ 91 mtx_lock(&(tq)->tq_mutex); \ 92 } while (0) 93 #define TQ_ASSERT_LOCKED(tq) mtx_assert(&(tq)->tq_mutex, MA_OWNED) 94 95 #define TQ_UNLOCK(tq) \ 96 do { \ 97 if ((tq)->tq_spin) \ 98 mtx_unlock_spin(&(tq)->tq_mutex); \ 99 else \ 100 mtx_unlock(&(tq)->tq_mutex); \ 101 } while (0) 102 #define TQ_ASSERT_UNLOCKED(tq) mtx_assert(&(tq)->tq_mutex, MA_NOTOWNED) 103 104 void 105 _timeout_task_init(struct taskqueue *queue, struct timeout_task *timeout_task, 106 int priority, task_fn_t func, void *context) 107 { 108 109 TASK_INIT(&timeout_task->t, priority, func, context); 110 callout_init_mtx(&timeout_task->c, &queue->tq_mutex, 111 CALLOUT_RETURNUNLOCKED); 112 timeout_task->q = queue; 113 timeout_task->f = 0; 114 } 115 116 static struct taskqueue * 117 _taskqueue_create(const char *name, int mflags, 118 taskqueue_enqueue_fn enqueue, void *context, 119 int mtxflags, const char *mtxname __unused) 120 { 121 struct taskqueue *queue; 122 char *tq_name; 123 124 tq_name = malloc(TASKQUEUE_NAMELEN, M_TASKQUEUE, mflags | M_ZERO); 125 if (tq_name == NULL) 126 return (NULL); 127 128 queue = malloc(sizeof(struct taskqueue), M_TASKQUEUE, mflags | M_ZERO); 129 if (queue == NULL) { 130 free(tq_name, M_TASKQUEUE); 131 return (NULL); 132 } 133 134 snprintf(tq_name, TASKQUEUE_NAMELEN, "%s", (name) ? name : "taskqueue"); 135 136 STAILQ_INIT(&queue->tq_queue); 137 TAILQ_INIT(&queue->tq_active); 138 queue->tq_enqueue = enqueue; 139 queue->tq_context = context; 140 queue->tq_name = tq_name; 141 queue->tq_spin = (mtxflags & MTX_SPIN) != 0; 142 queue->tq_flags |= TQ_FLAGS_ACTIVE; 143 if (enqueue == taskqueue_thread_enqueue) 144 queue->tq_flags |= TQ_FLAGS_UNLOCKED_ENQUEUE; 145 mtx_init(&queue->tq_mutex, tq_name, NULL, mtxflags); 146 147 return (queue); 148 } 149 150 struct taskqueue * 151 taskqueue_create(const char *name, int mflags, 152 taskqueue_enqueue_fn enqueue, void *context) 153 { 154 155 return _taskqueue_create(name, mflags, enqueue, context, 156 MTX_DEF, name); 157 } 158 159 void 160 taskqueue_set_callback(struct taskqueue *queue, 161 enum taskqueue_callback_type cb_type, taskqueue_callback_fn callback, 162 void *context) 163 { 164 165 KASSERT(((cb_type >= TASKQUEUE_CALLBACK_TYPE_MIN) && 166 (cb_type <= TASKQUEUE_CALLBACK_TYPE_MAX)), 167 ("Callback type %d not valid, must be %d-%d", cb_type, 168 TASKQUEUE_CALLBACK_TYPE_MIN, TASKQUEUE_CALLBACK_TYPE_MAX)); 169 KASSERT((queue->tq_callbacks[cb_type] == NULL), 170 ("Re-initialization of taskqueue callback?")); 171 172 queue->tq_callbacks[cb_type] = callback; 173 queue->tq_cb_contexts[cb_type] = context; 174 } 175 176 void 177 taskqueue_free(struct taskqueue *queue) 178 { 179 180 TQ_LOCK(queue); 181 queue->tq_flags &= ~TQ_FLAGS_ACTIVE; 182 taskqueue_terminate(queue->tq_threads, queue); 183 KASSERT(TAILQ_EMPTY(&queue->tq_active), ("Tasks still running?")); 184 KASSERT(queue->tq_callouts == 0, ("Armed timeout tasks")); 185 #ifdef __HAIKU__ 186 TQ_UNLOCK(queue); 187 #endif 188 mtx_destroy(&queue->tq_mutex); 189 free(queue->tq_threads, M_TASKQUEUE); 190 free(queue->tq_name, M_TASKQUEUE); 191 free(queue, M_TASKQUEUE); 192 } 193 194 static int 195 taskqueue_enqueue_locked(struct taskqueue *queue, struct task *task) 196 { 197 struct task *ins; 198 struct task *prev; 199 200 KASSERT(task->ta_func != NULL, ("enqueueing task with NULL func")); 201 /* 202 * Count multiple enqueues. 203 */ 204 if (task->ta_pending) { 205 if (task->ta_pending < USHRT_MAX) 206 task->ta_pending++; 207 TQ_UNLOCK(queue); 208 return (0); 209 } 210 211 /* 212 * Optimise the case when all tasks have the same priority. 213 */ 214 prev = STAILQ_LAST(&queue->tq_queue, task, ta_link); 215 if (!prev || prev->ta_priority >= task->ta_priority) { 216 STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link); 217 } else { 218 prev = NULL; 219 for (ins = STAILQ_FIRST(&queue->tq_queue); ins; 220 prev = ins, ins = STAILQ_NEXT(ins, ta_link)) 221 if (ins->ta_priority < task->ta_priority) 222 break; 223 224 if (prev) 225 STAILQ_INSERT_AFTER(&queue->tq_queue, prev, task, ta_link); 226 else 227 STAILQ_INSERT_HEAD(&queue->tq_queue, task, ta_link); 228 } 229 230 task->ta_pending = 1; 231 if ((queue->tq_flags & TQ_FLAGS_UNLOCKED_ENQUEUE) != 0) 232 TQ_UNLOCK(queue); 233 if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0) 234 queue->tq_enqueue(queue->tq_context); 235 if ((queue->tq_flags & TQ_FLAGS_UNLOCKED_ENQUEUE) == 0) 236 TQ_UNLOCK(queue); 237 238 /* Return with lock released. */ 239 return (0); 240 } 241 242 int 243 taskqueue_enqueue(struct taskqueue *queue, struct task *task) 244 { 245 int res; 246 247 TQ_LOCK(queue); 248 res = taskqueue_enqueue_locked(queue, task); 249 /* The lock is released inside. */ 250 251 return (res); 252 } 253 254 static void 255 taskqueue_timeout_func(void *arg) 256 { 257 struct taskqueue *queue; 258 struct timeout_task *timeout_task; 259 260 timeout_task = arg; 261 queue = timeout_task->q; 262 KASSERT((timeout_task->f & DT_CALLOUT_ARMED) != 0, ("Stray timeout")); 263 timeout_task->f &= ~DT_CALLOUT_ARMED; 264 queue->tq_callouts--; 265 taskqueue_enqueue_locked(timeout_task->q, &timeout_task->t); 266 /* The lock is released inside. */ 267 } 268 269 int 270 taskqueue_enqueue_timeout(struct taskqueue *queue, 271 struct timeout_task *timeout_task, int _ticks) 272 { 273 int res; 274 275 TQ_LOCK(queue); 276 KASSERT(timeout_task->q == NULL || timeout_task->q == queue, 277 ("Migrated queue")); 278 KASSERT(!queue->tq_spin, ("Timeout for spin-queue")); 279 timeout_task->q = queue; 280 res = timeout_task->t.ta_pending; 281 if (timeout_task->f & DT_DRAIN_IN_PROGRESS) { 282 /* Do nothing */ 283 TQ_UNLOCK(queue); 284 res = -1; 285 } else if (_ticks == 0) { 286 taskqueue_enqueue_locked(queue, &timeout_task->t); 287 /* The lock is released inside. */ 288 } else { 289 if ((timeout_task->f & DT_CALLOUT_ARMED) != 0) { 290 res++; 291 } else { 292 queue->tq_callouts++; 293 timeout_task->f |= DT_CALLOUT_ARMED; 294 if (_ticks < 0) 295 _ticks = -_ticks; /* Ignore overflow. */ 296 } 297 if (_ticks > 0) { 298 callout_reset(&timeout_task->c, _ticks, 299 taskqueue_timeout_func, timeout_task); 300 } 301 TQ_UNLOCK(queue); 302 } 303 return (res); 304 } 305 306 static void 307 taskqueue_task_nop_fn(void *context, int pending) 308 { 309 } 310 311 void 312 taskqueue_block(struct taskqueue *queue) 313 { 314 315 TQ_LOCK(queue); 316 queue->tq_flags |= TQ_FLAGS_BLOCKED; 317 TQ_UNLOCK(queue); 318 } 319 320 void 321 taskqueue_unblock(struct taskqueue *queue) 322 { 323 324 TQ_LOCK(queue); 325 queue->tq_flags &= ~TQ_FLAGS_BLOCKED; 326 if (!STAILQ_EMPTY(&queue->tq_queue)) 327 queue->tq_enqueue(queue->tq_context); 328 TQ_UNLOCK(queue); 329 } 330 331 static void 332 taskqueue_run_locked(struct taskqueue *queue) 333 { 334 struct taskqueue_busy tb; 335 struct taskqueue_busy *tb_first; 336 struct task *task; 337 int pending; 338 339 KASSERT(queue != NULL, ("tq is NULL")); 340 TQ_ASSERT_LOCKED(queue); 341 tb.tb_running = NULL; 342 343 while (STAILQ_FIRST(&queue->tq_queue)) { 344 TAILQ_INSERT_TAIL(&queue->tq_active, &tb, tb_link); 345 346 /* 347 * Carefully remove the first task from the queue and 348 * zero its pending count. 349 */ 350 task = STAILQ_FIRST(&queue->tq_queue); 351 KASSERT(task != NULL, ("task is NULL")); 352 STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link); 353 pending = task->ta_pending; 354 task->ta_pending = 0; 355 tb.tb_running = task; 356 TQ_UNLOCK(queue); 357 358 KASSERT(task->ta_func != NULL, ("task->ta_func is NULL")); 359 #ifdef __HAIKU__ 360 if ((task->ta_flags & TASK_NEEDSGIANT) != 0) 361 mtx_lock(&Giant); 362 #endif 363 task->ta_func(task->ta_context, pending); 364 #ifdef __HAIKU__ 365 if ((task->ta_flags & TASK_NEEDSGIANT) != 0) 366 mtx_unlock(&Giant); 367 #endif 368 369 TQ_LOCK(queue); 370 tb.tb_running = NULL; 371 372 TAILQ_REMOVE(&queue->tq_active, &tb, tb_link); 373 tb_first = TAILQ_FIRST(&queue->tq_active); 374 } 375 } 376 377 void 378 taskqueue_run(struct taskqueue *queue) 379 { 380 381 TQ_LOCK(queue); 382 taskqueue_run_locked(queue); 383 TQ_UNLOCK(queue); 384 } 385 386 static int 387 task_is_running(struct taskqueue *queue, struct task *task) 388 { 389 struct taskqueue_busy *tb; 390 391 TQ_ASSERT_LOCKED(queue); 392 TAILQ_FOREACH(tb, &queue->tq_active, tb_link) { 393 if (tb->tb_running == task) 394 return (1); 395 } 396 return (0); 397 } 398 399 static int 400 taskqueue_cancel_locked(struct taskqueue *queue, struct task *task, 401 u_int *pendp) 402 { 403 404 if (task->ta_pending > 0) 405 STAILQ_REMOVE(&queue->tq_queue, task, task, ta_link); 406 if (pendp != NULL) 407 *pendp = task->ta_pending; 408 task->ta_pending = 0; 409 return (task_is_running(queue, task) ? EBUSY : 0); 410 } 411 412 int 413 taskqueue_cancel(struct taskqueue *queue, struct task *task, u_int *pendp) 414 { 415 int error; 416 417 TQ_LOCK(queue); 418 error = taskqueue_cancel_locked(queue, task, pendp); 419 TQ_UNLOCK(queue); 420 421 return (error); 422 } 423 424 int 425 taskqueue_cancel_timeout(struct taskqueue *queue, 426 struct timeout_task *timeout_task, u_int *pendp) 427 { 428 u_int pending, pending1; 429 int error; 430 431 TQ_LOCK(queue); 432 pending = !!(callout_stop(&timeout_task->c) > 0); 433 error = taskqueue_cancel_locked(queue, &timeout_task->t, &pending1); 434 if ((timeout_task->f & DT_CALLOUT_ARMED) != 0) { 435 timeout_task->f &= ~DT_CALLOUT_ARMED; 436 queue->tq_callouts--; 437 } 438 TQ_UNLOCK(queue); 439 440 if (pendp != NULL) 441 *pendp = pending + pending1; 442 return (error); 443 } 444 445 void 446 taskqueue_drain_timeout(struct taskqueue *queue, 447 struct timeout_task *timeout_task) 448 { 449 450 /* 451 * Set flag to prevent timer from re-starting during drain: 452 */ 453 TQ_LOCK(queue); 454 KASSERT((timeout_task->f & DT_DRAIN_IN_PROGRESS) == 0, 455 ("Drain already in progress")); 456 timeout_task->f |= DT_DRAIN_IN_PROGRESS; 457 TQ_UNLOCK(queue); 458 459 callout_drain(&timeout_task->c); 460 taskqueue_drain(queue, &timeout_task->t); 461 462 /* 463 * Clear flag to allow timer to re-start: 464 */ 465 TQ_LOCK(queue); 466 timeout_task->f &= ~DT_DRAIN_IN_PROGRESS; 467 TQ_UNLOCK(queue); 468 } 469 470 int 471 taskqueue_start_threads(struct taskqueue **tqp, int count, int pri, 472 const char *format, ...) 473 { 474 char name[64]; 475 int error; 476 va_list vl; 477 478 va_start(vl, format); 479 vsnprintf(name, sizeof(name), format, vl); 480 va_end(vl); 481 482 error = _taskqueue_start_threads(tqp, count, pri, name); 483 return (error); 484 } 485 486 static inline void 487 taskqueue_run_callback(struct taskqueue *tq, 488 enum taskqueue_callback_type cb_type) 489 { 490 taskqueue_callback_fn tq_callback; 491 492 TQ_ASSERT_UNLOCKED(tq); 493 tq_callback = tq->tq_callbacks[cb_type]; 494 if (tq_callback != NULL) 495 tq_callback(tq->tq_cb_contexts[cb_type]); 496 } 497 498 int 499 taskqueue_member(struct taskqueue *queue, struct thread *td) 500 { 501 int i, j, ret = 0; 502 503 for (i = 0, j = 0; ; i++) { 504 if (queue->tq_threads[i] == NULL) 505 continue; 506 if (queue->tq_threads[i] == td) { 507 ret = 1; 508 break; 509 } 510 if (++j >= queue->tq_tcount) 511 break; 512 } 513 return (ret); 514 } 515 516 struct taskqueue * 517 taskqueue_create_fast(const char *name, int mflags, 518 taskqueue_enqueue_fn enqueue, void *context) 519 { 520 return _taskqueue_create(name, mflags, enqueue, context, 521 MTX_SPIN, "fast_taskqueue"); 522 } 523