taskqueue.h revision 145729 
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 145729 2005-05-01 00:38:11Z sam $
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, struct proc **);
54int	taskqueue_enqueue(struct taskqueue *queue, struct task *task);
55void	taskqueue_drain(struct taskqueue *queue, struct task *task);
56struct taskqueue *taskqueue_find(const char *name);
57void	taskqueue_free(struct taskqueue *queue);
58void	taskqueue_run(struct taskqueue *queue);
59
60/*
61 * Functions for dedicated thread taskqueues
62 */
63void	taskqueue_thread_loop(void *arg);
64void	taskqueue_thread_enqueue(void *context);
65
66/*
67 * Initialise a task structure.
68 */
69#define TASK_INIT(task, priority, func, context) do {	\
70	(task)->ta_pending = 0;				\
71	(task)->ta_priority = (priority);		\
72	(task)->ta_func = (func);			\
73	(task)->ta_context = (context);			\
74} while (0)
75
76/*
77 * Declare a reference to a taskqueue.
78 */
79#define TASKQUEUE_DECLARE(name)			\
80extern struct taskqueue *taskqueue_##name
81
82/*
83 * Define and initialise a taskqueue.
84 */
85#define TASKQUEUE_DEFINE(name, enqueue, context, init)			\
86									\
87struct taskqueue *taskqueue_##name;					\
88									\
89static void								\
90taskqueue_define_##name(void *arg)					\
91{									\
92	static struct proc *taskqueue_##name##_proc;			\
93	taskqueue_##name =						\
94	    taskqueue_create(#name, M_NOWAIT, (enqueue), (context),	\
95	    &taskqueue_##name##_proc);					\
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	kthread_create(taskqueue_thread_loop, &taskqueue_##name,	\
106	&taskqueue_##name##_proc, 0, 0, #name " taskq"))
107
108/*
109 * These queues are serviced by software interrupt handlers.  To enqueue
110 * a task, call taskqueue_enqueue(taskqueue_swi, &task) or
111 * taskqueue_enqueue(taskqueue_swi_giant, &task).
112 */
113TASKQUEUE_DECLARE(swi_giant);
114TASKQUEUE_DECLARE(swi);
115
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
122/*
123 * Queue for swi handlers dispatched from fast interrupt handlers.
124 * These are necessarily different from the above because the queue
125 * must be locked with spinlocks since sleep mutex's cannot be used
126 * from a fast interrupt handler context.
127 */
128TASKQUEUE_DECLARE(fast);
129int	taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task);
130
131#endif /* !_SYS_TASKQUEUE_H_ */
132