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 struct taskqueue *ta_queue; /* taskqueue enqueued on */ 61 int ta_pending; /* count times queued */ 62 int ta_priority; /* priority of task in queue */ 63 task_fn_t *ta_func; /* task handler */ 64 void *ta_context; /* argument for handler */ 65 }; 66 67 struct timeout_task { 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_optq(struct taskqueue *queue, 81 struct taskqueue **qpp, struct task *task); 82 int taskqueue_enqueue_timeout(struct taskqueue *queue, 83 struct timeout_task *timeout_task, int ticks); 84 int taskqueue_cancel(struct taskqueue *queue, struct task *task, 85 u_int *pendp); 86 int taskqueue_cancel_simple(struct task *task); 87 int taskqueue_cancel_timeout(struct taskqueue *queue, 88 struct timeout_task *timeout_task, u_int *pendp); 89 void taskqueue_drain(struct taskqueue *queue, struct task *task); 90 void taskqueue_drain_simple(struct task *task); 91 void taskqueue_drain_timeout(struct taskqueue *queue, 92 struct timeout_task *timeout_task); 93 struct taskqueue *taskqueue_find(const char *name); 94 void taskqueue_free(struct taskqueue *queue); 95 void taskqueue_block(struct taskqueue *queue); 96 void taskqueue_unblock(struct taskqueue *queue); 97 98 #define TASK_INITIALIZER(priority, func, context) \ 99 { .ta_queue = NULL, \ 100 .ta_pending = 0, \ 101 .ta_priority = (priority), \ 102 .ta_func = (func), \ 103 .ta_context = (context) } 104 105 /* 106 * Functions for dedicated thread taskqueues 107 */ 108 void taskqueue_thread_loop(void *arg); 109 void taskqueue_thread_enqueue(void *context); 110 111 /* 112 * Initialise a task structure. 113 */ 114 #define TASK_INIT(task, priority, func, context) do { \ 115 (task)->ta_queue = NULL; \ 116 (task)->ta_pending = 0; \ 117 (task)->ta_priority = (priority); \ 118 (task)->ta_func = (func); \ 119 (task)->ta_context = (context); \ 120 } while (0) 121 122 void _timeout_task_init(struct taskqueue *queue, 123 struct timeout_task *timeout_task, int priority, task_fn_t func, 124 void *context); 125 #define TIMEOUT_TASK_INIT(queue, timeout_task, priority, func, context) \ 126 _timeout_task_init(queue, timeout_task, priority, func, context); 127 128 /* 129 * Declare a reference to a taskqueue. 130 */ 131 #define TASKQUEUE_DECLARE(name) \ 132 extern struct taskqueue *taskqueue_##name 133 134 /* 135 * Define and initialise a taskqueue. 136 */ 137 #define TASKQUEUE_DEFINE(name, enqueue, context, init) \ 138 \ 139 struct taskqueue *taskqueue_##name; \ 140 \ 141 static void \ 142 taskqueue_define_##name(void *arg) \ 143 { \ 144 taskqueue_##name = \ 145 taskqueue_create(#name, M_INTWAIT, (enqueue), (context)); \ 146 init; \ 147 } \ 148 \ 149 SYSINIT(taskqueue_##name, SI_SUB_PRE_DRIVERS, SI_ORDER_SECOND, \ 150 taskqueue_define_##name, NULL); \ 151 \ 152 struct __hack 153 154 #define TASKQUEUE_DEFINE_THREAD(name) \ 155 TASKQUEUE_DEFINE(name, taskqueue_thread_enqueue, &taskqueue_##name, \ 156 taskqueue_start_threads(&taskqueue_##name, 1, \ 157 TDPRI_KERN_DAEMON, -1, "%s taskq", #name)) 158 /* 159 * This queue is serviced by a software interrupt handler. To enqueue 160 * a task, call taskqueue_enqueue(taskqueue_swi, &task). 161 */ 162 TASKQUEUE_DECLARE(swi); 163 TASKQUEUE_DECLARE(swi_mp); 164 165 /* 166 * This queue is serviced by a per-cpu kernel thread. To enqueue a task, call 167 * taskqueue_enqueue(taskqueue_thread[mycpuid], &task). 168 */ 169 extern struct taskqueue *taskqueue_thread[]; 170 171 #endif /* !_SYS_TASKQUEUE_H_ */ 172