sys/sys/taskqueue.h

   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  * $FreeBSD$
  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
  39 struct 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  */
  48 typedef void (*taskqueue_enqueue_fn)(void *context);
  49
  50 struct proc;
  51 struct taskqueue *taskqueue_create(const char *name, int mflags,
  52                                     taskqueue_enqueue_fn enqueue,
  53                                     void *context);
  54 int     taskqueue_start_threads(struct taskqueue **tqp, int count, int pri,
  55                                 const char *name, ...) __printflike(4, 5);
  56 int     taskqueue_enqueue(struct taskqueue *queue, struct task *task);
  57 void    taskqueue_drain(struct taskqueue *queue, struct task *task);
  58 struct taskqueue *taskqueue_find(const char *name);
  59 void    taskqueue_free(struct taskqueue *queue);
  60 void    taskqueue_run(struct taskqueue *queue);
  61
  62 /*
  63  * Functions for dedicated thread taskqueues
  64  */
  65 void    taskqueue_thread_loop(void *arg);
  66 void    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)                 \
  82 extern 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                                                                         \
  89 struct taskqueue *taskqueue_##name;                                     \
  90                                                                         \
  91 static void                                                             \
  92 taskqueue_define_##name(void *arg)                                      \
  93 {                                                                       \
  94         taskqueue_##name =                                              \
  95             taskqueue_create(#name, M_NOWAIT, (enqueue), (context));    \
  96         init;                                                           \
  97 }                                                                       \
  98                                                                         \
  99 SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND,            \
 100         taskqueue_define_##name, NULL)                                  \
 101                                                                         \
 102 struct __hack
 103 #define TASKQUEUE_DEFINE_THREAD(name)                                   \
 104 TASKQUEUE_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                                                                         \
 113 struct taskqueue *taskqueue_##name;                                     \
 114                                                                         \
 115 static void                                                             \
 116 taskqueue_define_##name(void *arg)                                      \
 117 {                                                                       \
 118         taskqueue_##name =                                              \
 119             taskqueue_create_fast(#name, M_NOWAIT, (enqueue),           \
 120             (context));                                                 \
 121         init;                                                           \
 122 }                                                                       \
 123                                                                         \
 124 SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND,            \
 125         taskqueue_define_##name, NULL)                                  \
 126                                                                         \
 127 struct __hack
 128 #define TASKQUEUE_FAST_DEFINE_THREAD(name)                              \
 129 TASKQUEUE_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  */
 138 TASKQUEUE_DECLARE(swi_giant);
 139 TASKQUEUE_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  */
 145 TASKQUEUE_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  */
 153 TASKQUEUE_DECLARE(fast);
 154 int     taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task);
 155 struct taskqueue *taskqueue_create_fast(const char *name, int mflags,
 156                                     taskqueue_enqueue_fn enqueue,
 157                                     void *context);
 158
 159 #endif /* !_SYS_TASKQUEUE_H_ */