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 1.3.2.2 2003/09/10 00:40:39 ken Exp $ 27 * $DragonFly: src/sys/sys/taskqueue.h,v 1.6 2005/09/21 18:58:55 hsu Exp $ 28 */ 29 30 #ifndef _SYS_TASKQUEUE_H_ 31 #define _SYS_TASKQUEUE_H_ 32 33 #if !defined(_KERNEL) 34 #error "This file should not be included by userland programs." 35 #endif 36 37 #include <sys/queue.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 taskqueue *taskqueue_create(const char *name, int mflags, 67 taskqueue_enqueue_fn enqueue, 68 void *context); 69 int taskqueue_enqueue(struct taskqueue *queue, struct task *task); 70 struct taskqueue *taskqueue_find(const char *name); 71 void taskqueue_free(struct taskqueue *queue); 72 void taskqueue_run(struct taskqueue *queue); 73 74 /* 75 * Initialise a task structure. 76 */ 77 #define TASK_INIT(task, priority, func, context) do { \ 78 (task)->ta_pending = 0; \ 79 (task)->ta_priority = (priority); \ 80 (task)->ta_func = (func); \ 81 (task)->ta_context = (context); \ 82 } while (0) 83 84 /* 85 * Declare a reference to a taskqueue. 86 */ 87 #define TASKQUEUE_DECLARE(name) \ 88 extern struct taskqueue *taskqueue_##name 89 90 /* 91 * Define and initialise a taskqueue. 92 */ 93 #define TASKQUEUE_DEFINE(name, enqueue, context, init) \ 94 \ 95 struct taskqueue *taskqueue_##name; \ 96 \ 97 static void \ 98 taskqueue_define_##name(void *arg) \ 99 { \ 100 taskqueue_##name = \ 101 taskqueue_create(#name, M_INTWAIT, (enqueue), (context)); \ 102 init; \ 103 } \ 104 \ 105 SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND, \ 106 taskqueue_define_##name, NULL) \ 107 \ 108 struct __hack 109 110 /* 111 * This queue is serviced by a software interrupt handler. To enqueue 112 * a task, call taskqueue_enqueue(taskqueue_swi, &task). 113 */ 114 TASKQUEUE_DECLARE(swi); 115 116 /* 117 * This queue is serviced by a per-cpu kernel thread. To enqueue a task, call 118 * taskqueue_enqueue(taskqueue_thread[mycpuid], &task). 119 */ 120 extern struct taskqueue *taskqueue_thread[]; 121 122 #endif /* !_SYS_TASKQUEUE_H_ */ 123