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 * $FreeBSD: src/sys/sys/taskqueue.h,v 1.31 2011/12/19 18:55:13 jhb Exp $ 27 */ 28 29 #ifndef _SYS_TASKQUEUE_H_ 30 #define _SYS_TASKQUEUE_H_ 31 32 #if !defined(_KERNEL) 33 #error "This file should not be included by userland programs." 34 #endif 35 36 #include <sys/queue.h> 37 #include <sys/callout.h> 38 39 struct taskqueue; 40 41 /* 42 * Each task includes a function which is called from 43 * taskqueue_run(). The first argument is taken from the 'ta_context' 44 * field of struct task and the second argument is a count of how many 45 * times the task was enqueued before the call to taskqueue_run(). 46 */ 47 typedef void task_fn_t(void *context, int pending); 48 49 /* 50 * A notification callback function which is called from 51 * taskqueue_enqueue(). The context argument is given in the call to 52 * taskqueue_create(). This function would normally be used to allow the 53 * queue to arrange to run itself later (e.g., by scheduling a software 54 * interrupt or waking a kernel thread). 55 */ 56 typedef void (*taskqueue_enqueue_fn)(void *context); 57 58 struct task { 59 STAILQ_ENTRY(task) ta_link; /* link for queue */ 60 int ta_pending; /* count times queued */ 61 int ta_priority; /* priority of task in queue */ 62 task_fn_t *ta_func; /* task handler */ 63 void *ta_context; /* argument for handler */ 64 }; 65 66 struct timeout_task { 67 struct taskqueue *q; 68 struct task t; 69 struct callout c; 70 int f; 71 }; 72 73 struct taskqueue *taskqueue_create(const char *name, int mflags, 74 taskqueue_enqueue_fn enqueue, 75 void *context); 76 int taskqueue_start_threads(struct taskqueue **tqp, int count, int pri, 77 int ncpu, const char *name, ...) 78 __printflike(5, 6); 79 int taskqueue_enqueue(struct taskqueue *queue, struct task *task); 80 int taskqueue_enqueue_timeout(struct taskqueue *queue, 81 struct timeout_task *timeout_task, int ticks); 82 int taskqueue_cancel(struct taskqueue *queue, struct task *task, 83 u_int *pendp); 84 int taskqueue_cancel_timeout(struct taskqueue *queue, 85 struct timeout_task *timeout_task, u_int *pendp); 86 void taskqueue_drain(struct taskqueue *queue, struct task *task); 87 void taskqueue_drain_timeout(struct taskqueue *queue, 88 struct timeout_task *timeout_task); 89 struct taskqueue *taskqueue_find(const char *name); 90 void taskqueue_free(struct taskqueue *queue); 91 void taskqueue_block(struct taskqueue *queue); 92 void taskqueue_unblock(struct taskqueue *queue); 93 94 #define TASK_INITIALIZER(priority, func, context) \ 95 { .ta_pending = 0, \ 96 .ta_priority = (priority), \ 97 .ta_func = (func), \ 98 .ta_context = (context) } 99 100 /* 101 * Functions for dedicated thread taskqueues 102 */ 103 void taskqueue_thread_loop(void *arg); 104 void taskqueue_thread_enqueue(void *context); 105 106 /* 107 * Initialise a task structure. 108 */ 109 #define TASK_INIT(task, priority, func, context) do { \ 110 (task)->ta_pending = 0; \ 111 (task)->ta_priority = (priority); \ 112 (task)->ta_func = (func); \ 113 (task)->ta_context = (context); \ 114 } while (0) 115 116 void _timeout_task_init(struct taskqueue *queue, 117 struct timeout_task *timeout_task, int priority, task_fn_t func, 118 void *context); 119 #define TIMEOUT_TASK_INIT(queue, timeout_task, priority, func, context) \ 120 _timeout_task_init(queue, timeout_task, priority, func, context); 121 122 /* 123 * Declare a reference to a taskqueue. 124 */ 125 #define TASKQUEUE_DECLARE(name) \ 126 extern struct taskqueue *taskqueue_##name 127 128 /* 129 * Define and initialise a taskqueue. 130 */ 131 #define TASKQUEUE_DEFINE(name, enqueue, context, init) \ 132 \ 133 struct taskqueue *taskqueue_##name; \ 134 \ 135 static void \ 136 taskqueue_define_##name(void *arg) \ 137 { \ 138 taskqueue_##name = \ 139 taskqueue_create(#name, M_INTWAIT, (enqueue), (context)); \ 140 init; \ 141 } \ 142 \ 143 SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND, \ 144 taskqueue_define_##name, NULL); \ 145 \ 146 struct __hack 147 148 #define TASKQUEUE_DEFINE_THREAD(name) \ 149 TASKQUEUE_DEFINE(name, taskqueue_thread_enqueue, &taskqueue_##name, \ 150 taskqueue_start_threads(&taskqueue_##name, 1, prio, \ 151 "%s taskq", #name)) 152 /* 153 * This queue is serviced by a software interrupt handler. To enqueue 154 * a task, call taskqueue_enqueue(taskqueue_swi, &task). 155 */ 156 TASKQUEUE_DECLARE(swi); 157 TASKQUEUE_DECLARE(swi_mp); 158 159 /* 160 * This queue is serviced by a per-cpu kernel thread. To enqueue a task, call 161 * taskqueue_enqueue(taskqueue_thread[mycpuid], &task). 162 */ 163 extern struct taskqueue *taskqueue_thread[]; 164 165 #endif /* !_SYS_TASKQUEUE_H_ */ 166