subr_taskqueue.c revision 69774
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 69774 2000-12-08 20:09:00Z phk $ 2761033Sdfr */ 2861033Sdfr 2961033Sdfr#include <sys/param.h> 3065822Sjhb#include <sys/bus.h> 3161033Sdfr#include <sys/queue.h> 3261033Sdfr#include <sys/systm.h> 3361033Sdfr#include <sys/kernel.h> 3461033Sdfr#include <sys/taskqueue.h> 3561033Sdfr#include <sys/interrupt.h> 3666698Sjhb#include <sys/ipl.h> 3761033Sdfr#include <sys/malloc.h> 3861033Sdfr 3969774Sphkstatic MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues"); 4061033Sdfr 4161033Sdfrstatic STAILQ_HEAD(taskqueue_list, taskqueue) taskqueue_queues; 4261033Sdfr 4367551Sjhbstatic struct intrhand *taskqueue_ih; 4467551Sjhb 4561033Sdfrstruct taskqueue { 4661033Sdfr STAILQ_ENTRY(taskqueue) tq_link; 4761033Sdfr STAILQ_HEAD(, task) tq_queue; 4861033Sdfr const char *tq_name; 4961033Sdfr taskqueue_enqueue_fn tq_enqueue; 5061033Sdfr void *tq_context; 5161033Sdfr int tq_draining; 5261033Sdfr}; 5361033Sdfr 5461033Sdfrstruct taskqueue * 5561033Sdfrtaskqueue_create(const char *name, int mflags, 5661033Sdfr taskqueue_enqueue_fn enqueue, void *context) 5761033Sdfr{ 5861033Sdfr struct taskqueue *queue; 5961033Sdfr static int once = 1; 6061033Sdfr int s; 6161033Sdfr 6261033Sdfr queue = malloc(sizeof(struct taskqueue), M_TASKQUEUE, mflags); 6361033Sdfr if (!queue) 6461033Sdfr return 0; 6561033Sdfr STAILQ_INIT(&queue->tq_queue); 6661033Sdfr queue->tq_name = name; 6761033Sdfr queue->tq_enqueue = enqueue; 6861033Sdfr queue->tq_context = context; 6961033Sdfr queue->tq_draining = 0; 7061033Sdfr 7161033Sdfr s = splhigh(); 7261033Sdfr if (once) { 7361033Sdfr STAILQ_INIT(&taskqueue_queues); 7461033Sdfr once = 0; 7561033Sdfr } 7661033Sdfr STAILQ_INSERT_TAIL(&taskqueue_queues, queue, tq_link); 7761033Sdfr splx(s); 7861033Sdfr 7961033Sdfr return queue; 8061033Sdfr} 8161033Sdfr 8261033Sdfrvoid 8361033Sdfrtaskqueue_free(struct taskqueue *queue) 8461033Sdfr{ 8561033Sdfr int s = splhigh(); 8661033Sdfr queue->tq_draining = 1; 8761033Sdfr splx(s); 8861033Sdfr 8961033Sdfr taskqueue_run(queue); 9061033Sdfr 9161033Sdfr s = splhigh(); 9261033Sdfr STAILQ_REMOVE(&taskqueue_queues, queue, taskqueue, tq_link); 9361033Sdfr splx(s); 9461033Sdfr 9561033Sdfr free(queue, M_TASKQUEUE); 9661033Sdfr} 9761033Sdfr 9861033Sdfrstruct taskqueue * 9961033Sdfrtaskqueue_find(const char *name) 10061033Sdfr{ 10161033Sdfr struct taskqueue *queue; 10261033Sdfr int s; 10361033Sdfr 10461033Sdfr s = splhigh(); 10561033Sdfr STAILQ_FOREACH(queue, &taskqueue_queues, tq_link) 10661033Sdfr if (!strcmp(queue->tq_name, name)) { 10761033Sdfr splx(s); 10861033Sdfr return queue; 10961033Sdfr } 11061033Sdfr splx(s); 11161033Sdfr return 0; 11261033Sdfr} 11361033Sdfr 11461033Sdfrint 11561033Sdfrtaskqueue_enqueue(struct taskqueue *queue, struct task *task) 11661033Sdfr{ 11761033Sdfr struct task *ins; 11861033Sdfr struct task *prev; 11961033Sdfr 12061033Sdfr int s = splhigh(); 12161033Sdfr 12261033Sdfr /* 12361033Sdfr * Don't allow new tasks on a queue which is being freed. 12461033Sdfr */ 12561033Sdfr if (queue->tq_draining) { 12661033Sdfr splx(s); 12761033Sdfr return EPIPE; 12861033Sdfr } 12961033Sdfr 13061033Sdfr /* 13161033Sdfr * Count multiple enqueues. 13261033Sdfr */ 13361033Sdfr if (task->ta_pending) { 13461033Sdfr task->ta_pending++; 13561033Sdfr splx(s); 13661033Sdfr return 0; 13761033Sdfr } 13861033Sdfr 13961033Sdfr /* 14061033Sdfr * Optimise the case when all tasks have the same priority. 14161033Sdfr */ 14264199Shsu prev = STAILQ_LAST(&queue->tq_queue, task, ta_link); 14361033Sdfr if (!prev || prev->ta_priority >= task->ta_priority) { 14461033Sdfr STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link); 14561033Sdfr } else { 14661033Sdfr prev = 0; 14761033Sdfr for (ins = STAILQ_FIRST(&queue->tq_queue); ins; 14861033Sdfr prev = ins, ins = STAILQ_NEXT(ins, ta_link)) 14961033Sdfr if (ins->ta_priority < task->ta_priority) 15061033Sdfr break; 15161033Sdfr 15261033Sdfr if (prev) 15361033Sdfr STAILQ_INSERT_AFTER(&queue->tq_queue, prev, task, ta_link); 15461033Sdfr else 15561033Sdfr STAILQ_INSERT_HEAD(&queue->tq_queue, task, ta_link); 15661033Sdfr } 15761033Sdfr 15861033Sdfr task->ta_pending = 1; 15961033Sdfr if (queue->tq_enqueue) 16061033Sdfr queue->tq_enqueue(queue->tq_context); 16161033Sdfr 16261033Sdfr splx(s); 16361033Sdfr 16461033Sdfr return 0; 16561033Sdfr} 16661033Sdfr 16761033Sdfrvoid 16861033Sdfrtaskqueue_run(struct taskqueue *queue) 16961033Sdfr{ 17061033Sdfr int s; 17161033Sdfr struct task *task; 17261033Sdfr int pending; 17361033Sdfr 17461033Sdfr s = splhigh(); 17561033Sdfr while (STAILQ_FIRST(&queue->tq_queue)) { 17661033Sdfr /* 17761033Sdfr * Carefully remove the first task from the queue and 17861033Sdfr * zero its pending count. 17961033Sdfr */ 18061033Sdfr task = STAILQ_FIRST(&queue->tq_queue); 18161033Sdfr STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link); 18261033Sdfr pending = task->ta_pending; 18361033Sdfr task->ta_pending = 0; 18461033Sdfr splx(s); 18561033Sdfr 18661033Sdfr task->ta_func(task->ta_context, pending); 18761033Sdfr 18861033Sdfr s = splhigh(); 18961033Sdfr } 19061033Sdfr splx(s); 19161033Sdfr} 19261033Sdfr 19361033Sdfrstatic void 19461033Sdfrtaskqueue_swi_enqueue(void *context) 19561033Sdfr{ 19667551Sjhb sched_swi(taskqueue_ih, SWI_NOSWITCH); 19761033Sdfr} 19861033Sdfr 19961033Sdfrstatic void 20067551Sjhbtaskqueue_swi_run(void *dummy) 20161033Sdfr{ 20261033Sdfr taskqueue_run(taskqueue_swi); 20361033Sdfr} 20461033Sdfr 20561033SdfrTASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, 0, 20667551Sjhb taskqueue_ih = sinthand_add("task queue", NULL, 20767551Sjhb taskqueue_swi_run, NULL, SWI_TQ, 0)); 208