subr_taskqueue.c revision 65822
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 65822 2000-09-13 18:33:25Z jhb $ 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> 3661033Sdfr#include <sys/malloc.h> 3761033Sdfr#include <machine/ipl.h> 3861033Sdfr 3961033SdfrMALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues"); 4061033Sdfr 4161033Sdfrstatic STAILQ_HEAD(taskqueue_list, taskqueue) taskqueue_queues; 4261033Sdfr 4361033Sdfrstruct taskqueue { 4461033Sdfr STAILQ_ENTRY(taskqueue) tq_link; 4561033Sdfr STAILQ_HEAD(, task) tq_queue; 4661033Sdfr const char *tq_name; 4761033Sdfr taskqueue_enqueue_fn tq_enqueue; 4861033Sdfr void *tq_context; 4961033Sdfr int tq_draining; 5061033Sdfr}; 5161033Sdfr 5261033Sdfrstruct taskqueue * 5361033Sdfrtaskqueue_create(const char *name, int mflags, 5461033Sdfr taskqueue_enqueue_fn enqueue, void *context) 5561033Sdfr{ 5661033Sdfr struct taskqueue *queue; 5761033Sdfr static int once = 1; 5861033Sdfr int s; 5961033Sdfr 6061033Sdfr queue = malloc(sizeof(struct taskqueue), M_TASKQUEUE, mflags); 6161033Sdfr if (!queue) 6261033Sdfr return 0; 6361033Sdfr STAILQ_INIT(&queue->tq_queue); 6461033Sdfr queue->tq_name = name; 6561033Sdfr queue->tq_enqueue = enqueue; 6661033Sdfr queue->tq_context = context; 6761033Sdfr queue->tq_draining = 0; 6861033Sdfr 6961033Sdfr s = splhigh(); 7061033Sdfr if (once) { 7161033Sdfr STAILQ_INIT(&taskqueue_queues); 7261033Sdfr once = 0; 7361033Sdfr } 7461033Sdfr STAILQ_INSERT_TAIL(&taskqueue_queues, queue, tq_link); 7561033Sdfr splx(s); 7661033Sdfr 7761033Sdfr return queue; 7861033Sdfr} 7961033Sdfr 8061033Sdfrvoid 8161033Sdfrtaskqueue_free(struct taskqueue *queue) 8261033Sdfr{ 8361033Sdfr int s = splhigh(); 8461033Sdfr queue->tq_draining = 1; 8561033Sdfr splx(s); 8661033Sdfr 8761033Sdfr taskqueue_run(queue); 8861033Sdfr 8961033Sdfr s = splhigh(); 9061033Sdfr STAILQ_REMOVE(&taskqueue_queues, queue, taskqueue, tq_link); 9161033Sdfr splx(s); 9261033Sdfr 9361033Sdfr free(queue, M_TASKQUEUE); 9461033Sdfr} 9561033Sdfr 9661033Sdfrstruct taskqueue * 9761033Sdfrtaskqueue_find(const char *name) 9861033Sdfr{ 9961033Sdfr struct taskqueue *queue; 10061033Sdfr int s; 10161033Sdfr 10261033Sdfr s = splhigh(); 10361033Sdfr STAILQ_FOREACH(queue, &taskqueue_queues, tq_link) 10461033Sdfr if (!strcmp(queue->tq_name, name)) { 10561033Sdfr splx(s); 10661033Sdfr return queue; 10761033Sdfr } 10861033Sdfr splx(s); 10961033Sdfr return 0; 11061033Sdfr} 11161033Sdfr 11261033Sdfrint 11361033Sdfrtaskqueue_enqueue(struct taskqueue *queue, struct task *task) 11461033Sdfr{ 11561033Sdfr struct task *ins; 11661033Sdfr struct task *prev; 11761033Sdfr 11861033Sdfr int s = splhigh(); 11961033Sdfr 12061033Sdfr /* 12161033Sdfr * Don't allow new tasks on a queue which is being freed. 12261033Sdfr */ 12361033Sdfr if (queue->tq_draining) { 12461033Sdfr splx(s); 12561033Sdfr return EPIPE; 12661033Sdfr } 12761033Sdfr 12861033Sdfr /* 12961033Sdfr * Count multiple enqueues. 13061033Sdfr */ 13161033Sdfr if (task->ta_pending) { 13261033Sdfr task->ta_pending++; 13361033Sdfr splx(s); 13461033Sdfr return 0; 13561033Sdfr } 13661033Sdfr 13761033Sdfr /* 13861033Sdfr * Optimise the case when all tasks have the same priority. 13961033Sdfr */ 14064199Shsu prev = STAILQ_LAST(&queue->tq_queue, task, ta_link); 14161033Sdfr if (!prev || prev->ta_priority >= task->ta_priority) { 14261033Sdfr STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link); 14361033Sdfr } else { 14461033Sdfr prev = 0; 14561033Sdfr for (ins = STAILQ_FIRST(&queue->tq_queue); ins; 14661033Sdfr prev = ins, ins = STAILQ_NEXT(ins, ta_link)) 14761033Sdfr if (ins->ta_priority < task->ta_priority) 14861033Sdfr break; 14961033Sdfr 15061033Sdfr if (prev) 15161033Sdfr STAILQ_INSERT_AFTER(&queue->tq_queue, prev, task, ta_link); 15261033Sdfr else 15361033Sdfr STAILQ_INSERT_HEAD(&queue->tq_queue, task, ta_link); 15461033Sdfr } 15561033Sdfr 15661033Sdfr task->ta_pending = 1; 15761033Sdfr if (queue->tq_enqueue) 15861033Sdfr queue->tq_enqueue(queue->tq_context); 15961033Sdfr 16061033Sdfr splx(s); 16161033Sdfr 16261033Sdfr return 0; 16361033Sdfr} 16461033Sdfr 16561033Sdfrvoid 16661033Sdfrtaskqueue_run(struct taskqueue *queue) 16761033Sdfr{ 16861033Sdfr int s; 16961033Sdfr struct task *task; 17061033Sdfr int pending; 17161033Sdfr 17261033Sdfr s = splhigh(); 17361033Sdfr while (STAILQ_FIRST(&queue->tq_queue)) { 17461033Sdfr /* 17561033Sdfr * Carefully remove the first task from the queue and 17661033Sdfr * zero its pending count. 17761033Sdfr */ 17861033Sdfr task = STAILQ_FIRST(&queue->tq_queue); 17961033Sdfr STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link); 18061033Sdfr pending = task->ta_pending; 18161033Sdfr task->ta_pending = 0; 18261033Sdfr splx(s); 18361033Sdfr 18461033Sdfr task->ta_func(task->ta_context, pending); 18561033Sdfr 18661033Sdfr s = splhigh(); 18761033Sdfr } 18861033Sdfr splx(s); 18961033Sdfr} 19061033Sdfr 19161033Sdfrstatic void 19261033Sdfrtaskqueue_swi_enqueue(void *context) 19361033Sdfr{ 19461033Sdfr setsofttq(); 19561033Sdfr} 19661033Sdfr 19761033Sdfrstatic void 19861033Sdfrtaskqueue_swi_run(void) 19961033Sdfr{ 20061033Sdfr taskqueue_run(taskqueue_swi); 20161033Sdfr} 20261033Sdfr 20361033SdfrTASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, 0, 20461033Sdfr register_swi(SWI_TQ, taskqueue_swi_run)); 205