subr_taskqueue.c revision 61033
161033Sdfr/*- 261033Sdfr * Copyright (c) 2000 Doug Rabson 361033Sdfr * All rights reserved. 461033Sdfr * 561033Sdfr * Redistribution and use in source and binary forms, with or without 661033Sdfr * modification, are permitted provided that the following conditions 761033Sdfr * are met: 861033Sdfr * 1. Redistributions of source code must retain the above copyright 961033Sdfr * notice, this list of conditions and the following disclaimer. 1061033Sdfr * 2. Redistributions in binary form must reproduce the above copyright 1161033Sdfr * notice, this list of conditions and the following disclaimer in the 1261033Sdfr * documentation and/or other materials provided with the distribution. 1361033Sdfr * 1461033Sdfr * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1561033Sdfr * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1661033Sdfr * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1761033Sdfr * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 1861033Sdfr * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1961033Sdfr * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2061033Sdfr * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2161033Sdfr * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2261033Sdfr * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2361033Sdfr * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2461033Sdfr * SUCH DAMAGE. 2561033Sdfr * 2661033Sdfr * $FreeBSD: head/sys/kern/subr_taskqueue.c 61033 2000-05-28 15:45:30Z dfr $ 2761033Sdfr */ 2861033Sdfr 2961033Sdfr#include <sys/param.h> 3061033Sdfr#include <sys/queue.h> 3161033Sdfr#include <sys/systm.h> 3261033Sdfr#include <sys/kernel.h> 3361033Sdfr#include <sys/taskqueue.h> 3461033Sdfr#include <sys/interrupt.h> 3561033Sdfr#include <sys/malloc.h> 3661033Sdfr#include <machine/ipl.h> 3761033Sdfr 3861033SdfrMALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues"); 3961033Sdfr 4061033Sdfrstatic STAILQ_HEAD(taskqueue_list, taskqueue) taskqueue_queues; 4161033Sdfr 4261033Sdfrstruct taskqueue { 4361033Sdfr STAILQ_ENTRY(taskqueue) tq_link; 4461033Sdfr STAILQ_HEAD(, task) tq_queue; 4561033Sdfr const char *tq_name; 4661033Sdfr taskqueue_enqueue_fn tq_enqueue; 4761033Sdfr void *tq_context; 4861033Sdfr int tq_draining; 4961033Sdfr}; 5061033Sdfr 5161033Sdfrstruct taskqueue * 5261033Sdfrtaskqueue_create(const char *name, int mflags, 5361033Sdfr taskqueue_enqueue_fn enqueue, void *context) 5461033Sdfr{ 5561033Sdfr struct taskqueue *queue; 5661033Sdfr static int once = 1; 5761033Sdfr int s; 5861033Sdfr 5961033Sdfr queue = malloc(sizeof(struct taskqueue), M_TASKQUEUE, mflags); 6061033Sdfr if (!queue) 6161033Sdfr return 0; 6261033Sdfr STAILQ_INIT(&queue->tq_queue); 6361033Sdfr queue->tq_name = name; 6461033Sdfr queue->tq_enqueue = enqueue; 6561033Sdfr queue->tq_context = context; 6661033Sdfr queue->tq_draining = 0; 6761033Sdfr 6861033Sdfr s = splhigh(); 6961033Sdfr if (once) { 7061033Sdfr STAILQ_INIT(&taskqueue_queues); 7161033Sdfr once = 0; 7261033Sdfr } 7361033Sdfr STAILQ_INSERT_TAIL(&taskqueue_queues, queue, tq_link); 7461033Sdfr splx(s); 7561033Sdfr 7661033Sdfr return queue; 7761033Sdfr} 7861033Sdfr 7961033Sdfrvoid 8061033Sdfrtaskqueue_free(struct taskqueue *queue) 8161033Sdfr{ 8261033Sdfr int s = splhigh(); 8361033Sdfr queue->tq_draining = 1; 8461033Sdfr splx(s); 8561033Sdfr 8661033Sdfr taskqueue_run(queue); 8761033Sdfr 8861033Sdfr s = splhigh(); 8961033Sdfr STAILQ_REMOVE(&taskqueue_queues, queue, taskqueue, tq_link); 9061033Sdfr splx(s); 9161033Sdfr 9261033Sdfr free(queue, M_TASKQUEUE); 9361033Sdfr} 9461033Sdfr 9561033Sdfrstruct taskqueue * 9661033Sdfrtaskqueue_find(const char *name) 9761033Sdfr{ 9861033Sdfr struct taskqueue *queue; 9961033Sdfr int s; 10061033Sdfr 10161033Sdfr s = splhigh(); 10261033Sdfr STAILQ_FOREACH(queue, &taskqueue_queues, tq_link) 10361033Sdfr if (!strcmp(queue->tq_name, name)) { 10461033Sdfr splx(s); 10561033Sdfr return queue; 10661033Sdfr } 10761033Sdfr splx(s); 10861033Sdfr return 0; 10961033Sdfr} 11061033Sdfr 11161033Sdfrint 11261033Sdfrtaskqueue_enqueue(struct taskqueue *queue, struct task *task) 11361033Sdfr{ 11461033Sdfr struct task *ins; 11561033Sdfr struct task *prev; 11661033Sdfr 11761033Sdfr int s = splhigh(); 11861033Sdfr 11961033Sdfr /* 12061033Sdfr * Don't allow new tasks on a queue which is being freed. 12161033Sdfr */ 12261033Sdfr if (queue->tq_draining) { 12361033Sdfr splx(s); 12461033Sdfr return EPIPE; 12561033Sdfr } 12661033Sdfr 12761033Sdfr /* 12861033Sdfr * Count multiple enqueues. 12961033Sdfr */ 13061033Sdfr if (task->ta_pending) { 13161033Sdfr task->ta_pending++; 13261033Sdfr splx(s); 13361033Sdfr return 0; 13461033Sdfr } 13561033Sdfr 13661033Sdfr /* 13761033Sdfr * Optimise the case when all tasks have the same priority. 13861033Sdfr */ 13961033Sdfr prev = STAILQ_LAST(&queue->tq_queue); 14061033Sdfr if (!prev || prev->ta_priority >= task->ta_priority) { 14161033Sdfr STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link); 14261033Sdfr } else { 14361033Sdfr prev = 0; 14461033Sdfr for (ins = STAILQ_FIRST(&queue->tq_queue); ins; 14561033Sdfr prev = ins, ins = STAILQ_NEXT(ins, ta_link)) 14661033Sdfr if (ins->ta_priority < task->ta_priority) 14761033Sdfr break; 14861033Sdfr 14961033Sdfr if (prev) 15061033Sdfr STAILQ_INSERT_AFTER(&queue->tq_queue, prev, task, ta_link); 15161033Sdfr else 15261033Sdfr STAILQ_INSERT_HEAD(&queue->tq_queue, task, ta_link); 15361033Sdfr } 15461033Sdfr 15561033Sdfr task->ta_pending = 1; 15661033Sdfr if (queue->tq_enqueue) 15761033Sdfr queue->tq_enqueue(queue->tq_context); 15861033Sdfr 15961033Sdfr splx(s); 16061033Sdfr 16161033Sdfr return 0; 16261033Sdfr} 16361033Sdfr 16461033Sdfrvoid 16561033Sdfrtaskqueue_run(struct taskqueue *queue) 16661033Sdfr{ 16761033Sdfr int s; 16861033Sdfr struct task *task; 16961033Sdfr int pending; 17061033Sdfr 17161033Sdfr s = splhigh(); 17261033Sdfr while (STAILQ_FIRST(&queue->tq_queue)) { 17361033Sdfr /* 17461033Sdfr * Carefully remove the first task from the queue and 17561033Sdfr * zero its pending count. 17661033Sdfr */ 17761033Sdfr task = STAILQ_FIRST(&queue->tq_queue); 17861033Sdfr STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link); 17961033Sdfr pending = task->ta_pending; 18061033Sdfr task->ta_pending = 0; 18161033Sdfr splx(s); 18261033Sdfr 18361033Sdfr task->ta_func(task->ta_context, pending); 18461033Sdfr 18561033Sdfr s = splhigh(); 18661033Sdfr } 18761033Sdfr splx(s); 18861033Sdfr} 18961033Sdfr 19061033Sdfrstatic void 19161033Sdfrtaskqueue_swi_enqueue(void *context) 19261033Sdfr{ 19361033Sdfr setsofttq(); 19461033Sdfr} 19561033Sdfr 19661033Sdfrstatic void 19761033Sdfrtaskqueue_swi_run(void) 19861033Sdfr{ 19961033Sdfr taskqueue_run(taskqueue_swi); 20061033Sdfr} 20161033Sdfr 20261033SdfrTASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, 0, 20361033Sdfr register_swi(SWI_TQ, taskqueue_swi_run)); 204