Synchronize the USB, CAM, and TASKQUEUE subsystems with FreeBSD RELENG_4.
[dragonfly.git] / sys / sys / taskqueue.h
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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 *
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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 1.3 2003/12/29 06:42:07 dillon Exp $
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28 */
29
30#ifndef _SYS_TASKQUEUE_H_
31#define _SYS_TASKQUEUE_H_
32
33#ifndef _KERNEL
34#error "no user-servicable parts inside"
35#endif
36
37#include <sys/queue.h>
38
39struct 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 */
47typedef 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 */
56typedef void (*taskqueue_enqueue_fn)(void *context);
57
58struct 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
66struct taskqueue *taskqueue_create(const char *name, int mflags,
67 taskqueue_enqueue_fn enqueue,
68 void *context);
69int taskqueue_enqueue(struct taskqueue *queue, struct task *task);
70struct taskqueue *taskqueue_find(const char *name);
71void taskqueue_free(struct taskqueue *queue);
72void 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) \
88extern struct taskqueue *taskqueue_##name
89
90/*
91 * Define and initialise a taskqueue.
92 */
93#define TASKQUEUE_DEFINE(name, enqueue, context, init) \
94 \
95struct taskqueue *taskqueue_##name; \
96 \
97static void \
98taskqueue_define_##name(void *arg) \
99{ \
100 taskqueue_##name = \
101 taskqueue_create(#name, M_NOWAIT, (enqueue), (context)); \
102 init; \
103} \
104 \
105SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND, \
106 taskqueue_define_##name, NULL) \
107 \
108struct __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 */
114TASKQUEUE_DECLARE(swi);
115
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116/*
117 * This queue is serviced by a kernel thread. To enqueue a task, call
118 * taskqueue_enqueue(taskqueue_thread, &task).
119 */
120TASKQUEUE_DECLARE(thread);
121
984263bc 122#endif /* !_SYS_TASKQUEUE_H_ */