2 * Copyright (c) 2000 Doug Rabson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 #ifndef _SYS_TASKQUEUE_H_
30 #define _SYS_TASKQUEUE_H_
33 #error "no user-servicable parts inside"
36 #include <sys/queue.h>
41 * Each task includes a function which is called from
42 * taskqueue_run(). The first argument is taken from the 'ta_context'
43 * field of struct task and the second argument is a count of how many
44 * times the task was enqueued before the call to taskqueue_run().
46 typedef void task_fn_t(void *context, int pending);
49 * A notification callback function which is called from
50 * taskqueue_enqueue(). The context argument is given in the call to
51 * taskqueue_create(). This function would normally be used to allow the
52 * queue to arrange to run itself later (e.g., by scheduling a software
53 * interrupt or waking a kernel thread).
55 typedef void (*taskqueue_enqueue_fn)(void *context);
58 STAILQ_ENTRY(task) ta_link; /* link for queue */
59 int ta_pending; /* count times queued */
60 int ta_priority; /* priority of task in queue */
61 task_fn_t *ta_func; /* task handler */
62 void *ta_context; /* argument for handler */
65 struct taskqueue *taskqueue_create(const char *name, int mflags,
66 taskqueue_enqueue_fn enqueue,
68 int taskqueue_enqueue(struct taskqueue *queue, struct task *task);
69 struct taskqueue *taskqueue_find(const char *name);
70 void taskqueue_free(struct taskqueue *queue);
71 void taskqueue_run(struct taskqueue *queue);
74 * Initialise a task structure.
76 #define TASK_INIT(task, priority, func, context) do { \
77 (task)->ta_pending = 0; \
78 (task)->ta_priority = (priority); \
79 (task)->ta_func = (func); \
80 (task)->ta_context = (context); \
84 * Declare a reference to a taskqueue.
86 #define TASKQUEUE_DECLARE(name) \
87 extern struct taskqueue *taskqueue_##name
90 * Define and initialise a taskqueue.
92 #define TASKQUEUE_DEFINE(name, enqueue, context, init) \
94 struct taskqueue *taskqueue_##name; \
97 taskqueue_define_##name(void *arg) \
100 taskqueue_create(#name, M_NOWAIT, (enqueue), (context)); \
104 SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND, \
105 taskqueue_define_##name, NULL) \
110 * This queue is serviced by a software interrupt handler. To enqueue
111 * a task, call taskqueue_enqueue(taskqueue_swi, &task).
113 TASKQUEUE_DECLARE(swi);
115 #endif /* !_SYS_TASKQUEUE_H_ */