taskqueue.h revision 154333 
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: head/sys/sys/taskqueue.h 154333 2006-01-14 01:55:24Z scottl $
27 */
28
29#ifndef _SYS_TASKQUEUE_H_
30#define _SYS_TASKQUEUE_H_
31
32#ifndef _KERNEL
33#error "no user-servicable parts inside"
34#endif
35
36#include <sys/queue.h>
37#include <sys/_task.h>
38
39struct taskqueue;
40
41/*
42 * A notification callback function which is called from
43 * taskqueue_enqueue().  The context argument is given in the call to
44 * taskqueue_create().  This function would normally be used to allow the
45 * queue to arrange to run itself later (e.g., by scheduling a software
46 * interrupt or waking a kernel thread).
47 */
48typedef void (*taskqueue_enqueue_fn)(void *context);
49
50struct proc;
51struct taskqueue *taskqueue_create(const char *name, int mflags,
52				    taskqueue_enqueue_fn enqueue,
53				    void *context);
54int	taskqueue_start_threads(struct taskqueue **tqp, int count, int pri,
55				const char *name, ...) __printflike(4, 5);
56int	taskqueue_enqueue(struct taskqueue *queue, struct task *task);
57void	taskqueue_drain(struct taskqueue *queue, struct task *task);
58struct taskqueue *taskqueue_find(const char *name);
59void	taskqueue_free(struct taskqueue *queue);
60void	taskqueue_run(struct taskqueue *queue);
61
62/*
63 * Functions for dedicated thread taskqueues
64 */
65void	taskqueue_thread_loop(void *arg);
66void	taskqueue_thread_enqueue(void *context);
67
68/*
69 * Initialise a task structure.
70 */
71#define TASK_INIT(task, priority, func, context) do {	\
72	(task)->ta_pending = 0;				\
73	(task)->ta_priority = (priority);		\
74	(task)->ta_func = (func);			\
75	(task)->ta_context = (context);			\
76} while (0)
77
78/*
79 * Declare a reference to a taskqueue.
80 */
81#define TASKQUEUE_DECLARE(name)			\
82extern struct taskqueue *taskqueue_##name
83
84/*
85 * Define and initialise a global taskqueue that uses sleep mutexes.
86 */
87#define TASKQUEUE_DEFINE(name, enqueue, context, init)			\
88									\
89struct taskqueue *taskqueue_##name;					\
90									\
91static void								\
92taskqueue_define_##name(void *arg)					\
93{									\
94	taskqueue_##name =						\
95	    taskqueue_create(#name, M_NOWAIT, (enqueue), (context));	\
96	init;								\
97}									\
98									\
99SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND,		\
100	taskqueue_define_##name, NULL)					\
101									\
102struct __hack
103#define TASKQUEUE_DEFINE_THREAD(name)					\
104TASKQUEUE_DEFINE(name, taskqueue_thread_enqueue, &taskqueue_##name,	\
105	taskqueue_start_threads(&taskqueue_##name, 1, PWAIT,		\
106	"%s taskq", #name))
107
108/*
109 * Define and initialise a global taskqueue that uses spin mutexes.
110 */
111#define TASKQUEUE_FAST_DEFINE(name, enqueue, context, init)		\
112									\
113struct taskqueue *taskqueue_##name;					\
114									\
115static void								\
116taskqueue_define_##name(void *arg)					\
117{									\
118	taskqueue_##name =						\
119	    taskqueue_create_fast(#name, M_NOWAIT, (enqueue),		\
120	    (context));							\
121	init;								\
122}									\
123									\
124SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND,		\
125	taskqueue_define_##name, NULL)					\
126									\
127struct __hack
128#define TASKQUEUE_FAST_DEFINE_THREAD(name)				\
129TASKQUEUE_FAST_DEFINE(name, taskqueue_thread_enqueue,			\
130	&taskqueue_##name, taskqueue_start_threads(&taskqueue_##name	\
131	1, PWAIT, "%s taskq", #name))
132
133/*
134 * These queues are serviced by software interrupt handlers.  To enqueue
135 * a task, call taskqueue_enqueue(taskqueue_swi, &task) or
136 * taskqueue_enqueue(taskqueue_swi_giant, &task).
137 */
138TASKQUEUE_DECLARE(swi_giant);
139TASKQUEUE_DECLARE(swi);
140
141/*
142 * This queue is serviced by a kernel thread.  To enqueue a task, call
143 * taskqueue_enqueue(taskqueue_thread, &task).
144 */
145TASKQUEUE_DECLARE(thread);
146
147/*
148 * Queue for swi handlers dispatched from fast interrupt handlers.
149 * These are necessarily different from the above because the queue
150 * must be locked with spinlocks since sleep mutex's cannot be used
151 * from a fast interrupt handler context.
152 */
153TASKQUEUE_DECLARE(fast);
154int	taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task);
155struct taskqueue *taskqueue_create_fast(const char *name, int mflags,
156				    taskqueue_enqueue_fn enqueue,
157				    void *context);
158
159#endif /* !_SYS_TASKQUEUE_H_ */
160