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 
40 struct taskqueue;
41 struct thread;
42 
43 struct timeout_task {
44 	struct taskqueue *q;
45 	struct task t;
46 	struct callout c;
47 	int    f;
48 };
49 
50 enum 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 
58 typedef 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  */
67 typedef void (*taskqueue_enqueue_fn)(void *context);
68 
69 struct taskqueue *taskqueue_create(const char *name, int mflags,
70 				    taskqueue_enqueue_fn enqueue,
71 				    void *context);
72 int	taskqueue_start_threads(struct taskqueue **tqp, int count, int pri,
73 				const char *name, ...) __printflike(4, 5);
74 int	taskqueue_enqueue(struct taskqueue *queue, struct task *task);
75 int	taskqueue_enqueue_timeout(struct taskqueue *queue,
76 	    struct timeout_task *timeout_task, int ticks);
77 int	taskqueue_poll_is_busy(struct taskqueue *queue, struct task *task);
78 int	taskqueue_cancel(struct taskqueue *queue, struct task *task,
79 	    u_int *pendp);
80 int	taskqueue_cancel_timeout(struct taskqueue *queue,
81 	    struct timeout_task *timeout_task, u_int *pendp);
82 void	taskqueue_drain(struct taskqueue *queue, struct task *task);
83 void	taskqueue_drain_timeout(struct taskqueue *queue,
84 	    struct timeout_task *timeout_task);
85 void	taskqueue_drain_all(struct taskqueue *queue);
86 void	taskqueue_free(struct taskqueue *queue);
87 void	taskqueue_run(struct taskqueue *queue);
88 void	taskqueue_block(struct taskqueue *queue);
89 void	taskqueue_unblock(struct taskqueue *queue);
90 int	taskqueue_member(struct taskqueue *queue, struct thread *td);
91 void	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  */
104 void	taskqueue_thread_loop(void *arg);
105 void	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 
117 void _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)			\
127 extern 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 									\
134 struct taskqueue *taskqueue_##name;					\
135 									\
136 static void								\
137 taskqueue_define_##name(void *arg)					\
138 {									\
139 	taskqueue_##name =						\
140 	    taskqueue_create(#name, M_WAITOK, (enqueue), (context));	\
141 	init;								\
142 }									\
143 									\
144 SYSINIT(taskqueue_##name, SI_SUB_TASKQ, SI_ORDER_SECOND,		\
145 	taskqueue_define_##name, NULL);					\
146 									\
147 struct __hack
148 #define TASKQUEUE_DEFINE_THREAD(name)					\
149 TASKQUEUE_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 									\
158 struct taskqueue *taskqueue_##name;					\
159 									\
160 static void								\
161 taskqueue_define_##name(void *arg)					\
162 {									\
163 	taskqueue_##name =						\
164 	    taskqueue_create_fast(#name, M_WAITOK, (enqueue),		\
165 	    (context));							\
166 	init;								\
167 }									\
168 									\
169 SYSINIT(taskqueue_##name, SI_SUB_TASKQ, SI_ORDER_SECOND,		\
170 	taskqueue_define_##name, NULL);					\
171 									\
172 struct __hack
173 #define TASKQUEUE_FAST_DEFINE_THREAD(name)				\
174 TASKQUEUE_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  */
183 TASKQUEUE_DECLARE(swi_giant);
184 TASKQUEUE_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  */
190 TASKQUEUE_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  */
198 TASKQUEUE_DECLARE(fast);
199 int	taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task);
200 struct taskqueue *taskqueue_create_fast(const char *name, int mflags,
201 				    taskqueue_enqueue_fn enqueue,
202 				    void *context);
203 
204 #endif /* !_SYS_TASKQUEUE_H_ */
205