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: stable/10/sys/sys/taskqueue.h 337042 2018-08-01 13:13:43Z hselasky $
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#include <sys/_callout.h>
39
40struct taskqueue;
41struct thread;
42
43struct timeout_task {
44	struct taskqueue *q;
45	struct task t;
46	struct callout c;
47	int    f;
48};
49
50enum taskqueue_callback_type {
51	TASKQUEUE_CALLBACK_TYPE_INIT,
52	TASKQUEUE_CALLBACK_TYPE_SHUTDOWN,
53};
54#define	TASKQUEUE_CALLBACK_TYPE_MIN	TASKQUEUE_CALLBACK_TYPE_INIT
55#define	TASKQUEUE_CALLBACK_TYPE_MAX	TASKQUEUE_CALLBACK_TYPE_SHUTDOWN
56#define	TASKQUEUE_NUM_CALLBACKS		TASKQUEUE_CALLBACK_TYPE_MAX + 1
57
58typedef void (*taskqueue_callback_fn)(void *context);
59
60/*
61 * A notification callback function which is called from
62 * taskqueue_enqueue().  The context argument is given in the call to
63 * taskqueue_create().  This function would normally be used to allow the
64 * queue to arrange to run itself later (e.g., by scheduling a software
65 * interrupt or waking a kernel thread).
66 */
67typedef void (*taskqueue_enqueue_fn)(void *context);
68
69struct taskqueue *taskqueue_create(const char *name, int mflags,
70				    taskqueue_enqueue_fn enqueue,
71				    void *context);
72int	taskqueue_start_threads(struct taskqueue **tqp, int count, int pri,
73				const char *name, ...) __printflike(4, 5);
74int	taskqueue_enqueue(struct taskqueue *queue, struct task *task);
75int	taskqueue_enqueue_timeout(struct taskqueue *queue,
76	    struct timeout_task *timeout_task, int ticks);
77int	taskqueue_poll_is_busy(struct taskqueue *queue, struct task *task);
78int	taskqueue_cancel(struct taskqueue *queue, struct task *task,
79	    u_int *pendp);
80int	taskqueue_cancel_timeout(struct taskqueue *queue,
81	    struct timeout_task *timeout_task, u_int *pendp);
82void	taskqueue_drain(struct taskqueue *queue, struct task *task);
83void	taskqueue_drain_timeout(struct taskqueue *queue,
84	    struct timeout_task *timeout_task);
85void	taskqueue_drain_all(struct taskqueue *queue);
86void	taskqueue_free(struct taskqueue *queue);
87void	taskqueue_run(struct taskqueue *queue);
88void	taskqueue_block(struct taskqueue *queue);
89void	taskqueue_unblock(struct taskqueue *queue);
90int	taskqueue_member(struct taskqueue *queue, struct thread *td);
91void	taskqueue_set_callback(struct taskqueue *queue,
92	    enum taskqueue_callback_type cb_type,
93	    taskqueue_callback_fn callback, void *context);
94
95#define TASK_INITIALIZER(priority, func, context)	\
96	{ .ta_pending = 0,				\
97	  .ta_priority = (priority),			\
98	  .ta_func = (func),				\
99	  .ta_context = (context) }
100
101/*
102 * Functions for dedicated thread taskqueues
103 */
104void	taskqueue_thread_loop(void *arg);
105void	taskqueue_thread_enqueue(void *context);
106
107/*
108 * Initialise a task structure.
109 */
110#define TASK_INIT(task, priority, func, context) do {	\
111	(task)->ta_pending = 0;				\
112	(task)->ta_priority = (priority);		\
113	(task)->ta_func = (func);			\
114	(task)->ta_context = (context);			\
115} while (0)
116
117void _timeout_task_init(struct taskqueue *queue,
118	    struct timeout_task *timeout_task, int priority, task_fn_t func,
119	    void *context);
120#define	TIMEOUT_TASK_INIT(queue, timeout_task, priority, func, context) \
121	_timeout_task_init(queue, timeout_task, priority, func, context);
122
123/*
124 * Declare a reference to a taskqueue.
125 */
126#define TASKQUEUE_DECLARE(name)			\
127extern struct taskqueue *taskqueue_##name
128
129/*
130 * Define and initialise a global taskqueue that uses sleep mutexes.
131 */
132#define TASKQUEUE_DEFINE(name, enqueue, context, init)			\
133									\
134struct taskqueue *taskqueue_##name;					\
135									\
136static void								\
137taskqueue_define_##name(void *arg)					\
138{									\
139	taskqueue_##name =						\
140	    taskqueue_create(#name, M_WAITOK, (enqueue), (context));	\
141	init;								\
142}									\
143									\
144SYSINIT(taskqueue_##name, SI_SUB_TASKQ, SI_ORDER_SECOND,		\
145	taskqueue_define_##name, NULL);					\
146									\
147struct __hack
148#define TASKQUEUE_DEFINE_THREAD(name)					\
149TASKQUEUE_DEFINE(name, taskqueue_thread_enqueue, &taskqueue_##name,	\
150	taskqueue_start_threads(&taskqueue_##name, 1, PWAIT,		\
151	"%s taskq", #name))
152
153/*
154 * Define and initialise a global taskqueue that uses spin mutexes.
155 */
156#define TASKQUEUE_FAST_DEFINE(name, enqueue, context, init)		\
157									\
158struct taskqueue *taskqueue_##name;					\
159									\
160static void								\
161taskqueue_define_##name(void *arg)					\
162{									\
163	taskqueue_##name =						\
164	    taskqueue_create_fast(#name, M_WAITOK, (enqueue),		\
165	    (context));							\
166	init;								\
167}									\
168									\
169SYSINIT(taskqueue_##name, SI_SUB_TASKQ, SI_ORDER_SECOND,		\
170	taskqueue_define_##name, NULL);					\
171									\
172struct __hack
173#define TASKQUEUE_FAST_DEFINE_THREAD(name)				\
174TASKQUEUE_FAST_DEFINE(name, taskqueue_thread_enqueue,			\
175	&taskqueue_##name, taskqueue_start_threads(&taskqueue_##name	\
176	1, PWAIT, "%s taskq", #name))
177
178/*
179 * These queues are serviced by software interrupt handlers.  To enqueue
180 * a task, call taskqueue_enqueue(taskqueue_swi, &task) or
181 * taskqueue_enqueue(taskqueue_swi_giant, &task).
182 */
183TASKQUEUE_DECLARE(swi_giant);
184TASKQUEUE_DECLARE(swi);
185
186/*
187 * This queue is serviced by a kernel thread.  To enqueue a task, call
188 * taskqueue_enqueue(taskqueue_thread, &task).
189 */
190TASKQUEUE_DECLARE(thread);
191
192/*
193 * Queue for swi handlers dispatched from fast interrupt handlers.
194 * These are necessarily different from the above because the queue
195 * must be locked with spinlocks since sleep mutex's cannot be used
196 * from a fast interrupt handler context.
197 */
198TASKQUEUE_DECLARE(fast);
199int	taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task);
200struct taskqueue *taskqueue_create_fast(const char *name, int mflags,
201				    taskqueue_enqueue_fn enqueue,
202				    void *context);
203
204#endif /* !_SYS_TASKQUEUE_H_ */
205