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 struct thread;
  41
  42 /*
  43  * A notification callback function which is called from
  44  * taskqueue_enqueue().  The context argument is given in the call to
  45  * taskqueue_create().  This function would normally be used to allow the
  46  * queue to arrange to run itself later (e.g., by scheduling a software
  47  * interrupt or waking a kernel thread).
  48  */
  49 typedef void (*taskqueue_enqueue_fn)(void *context);
  50
  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 void    taskqueue_drain_all(struct taskqueue *queue);
  59 void    taskqueue_free(struct taskqueue *queue);
  60 void    taskqueue_run(struct taskqueue *queue);
  61 void    taskqueue_block(struct taskqueue *queue);
  62 void    taskqueue_unblock(struct taskqueue *queue);
  63 int     taskqueue_member(struct taskqueue *queue, struct thread *td);
  64
  65 #define TASK_INITIALIZER(priority, func, context)       \
  66         { .ta_pending = 0,                              \
  67           .ta_priority = (priority),                    \
  68           .ta_func = (func),                            \
  69           .ta_context = (context) }
  70
  71 /*
  72  * Functions for dedicated thread taskqueues
  73  */
  74 void    taskqueue_thread_loop(void *arg);
  75 void    taskqueue_thread_enqueue(void *context);
  76
  77 /*
  78  * Initialise a task structure.
  79  */
  80 #define TASK_INIT(task, priority, func, context) do {   \
  81         (task)->ta_pending = 0;                         \
  82         (task)->ta_priority = (priority);               \
  83         (task)->ta_func = (func);                       \
  84         (task)->ta_context = (context);                 \
  85 } while (0)
  86
  87 /*
  88  * Declare a reference to a taskqueue.
  89  */
  90 #define TASKQUEUE_DECLARE(name)                 \
  91 extern struct taskqueue *taskqueue_##name
  92
  93 /*
  94  * Define and initialise a global taskqueue that uses sleep mutexes.
  95  */
  96 #define TASKQUEUE_DEFINE(name, enqueue, context, init)                  \
  97                                                                         \
  98 struct taskqueue *taskqueue_##name;                                     \
  99                                                                         \
 100 static void                                                             \
 101 taskqueue_define_##name(void *arg)                                      \
 102 {                                                                       \
 103         taskqueue_##name =                                              \
 104             taskqueue_create(#name, M_WAITOK, (enqueue), (context));    \
 105         init;                                                           \
 106 }                                                                       \
 107                                                                         \
 108 SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND,            \
 109         taskqueue_define_##name, NULL);                                 \
 110                                                                         \
 111 struct __hack
 112 #define TASKQUEUE_DEFINE_THREAD(name)                                   \
 113 TASKQUEUE_DEFINE(name, taskqueue_thread_enqueue, &taskqueue_##name,     \
 114         taskqueue_start_threads(&taskqueue_##name, 1, PWAIT,            \
 115         "%s taskq", #name))
 116
 117 /*
 118  * Define and initialise a global taskqueue that uses spin mutexes.
 119  */
 120 #define TASKQUEUE_FAST_DEFINE(name, enqueue, context, init)             \
 121                                                                         \
 122 struct taskqueue *taskqueue_##name;                                     \
 123                                                                         \
 124 static void                                                             \
 125 taskqueue_define_##name(void *arg)                                      \
 126 {                                                                       \
 127         taskqueue_##name =                                              \
 128             taskqueue_create_fast(#name, M_WAITOK, (enqueue),           \
 129             (context));                                                 \
 130         init;                                                           \
 131 }                                                                       \
 132                                                                         \
 133 SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND,            \
 134         taskqueue_define_##name, NULL);                                 \
 135                                                                         \
 136 struct __hack
 137 #define TASKQUEUE_FAST_DEFINE_THREAD(name)                              \
 138 TASKQUEUE_FAST_DEFINE(name, taskqueue_thread_enqueue,                   \
 139         &taskqueue_##name, taskqueue_start_threads(&taskqueue_##name    \
 140         1, PWAIT, "%s taskq", #name))
 141
 142 /*
 143  * These queues are serviced by software interrupt handlers.  To enqueue
 144  * a task, call taskqueue_enqueue(taskqueue_swi, &task) or
 145  * taskqueue_enqueue(taskqueue_swi_giant, &task).
 146  */
 147 TASKQUEUE_DECLARE(swi_giant);
 148 TASKQUEUE_DECLARE(swi);
 149
 150 /*
 151  * This queue is serviced by a kernel thread.  To enqueue a task, call
 152  * taskqueue_enqueue(taskqueue_thread, &task).
 153  */
 154 TASKQUEUE_DECLARE(thread);
 155
 156 /*
 157  * Queue for swi handlers dispatched from fast interrupt handlers.
 158  * These are necessarily different from the above because the queue
 159  * must be locked with spinlocks since sleep mutex's cannot be used
 160  * from a fast interrupt handler context.
 161  */
 162 TASKQUEUE_DECLARE(fast);
 163 int     taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task);
 164 struct taskqueue *taskqueue_create_fast(const char *name, int mflags,
 165                                     taskqueue_enqueue_fn enqueue,
 166                                     void *context);
 167
 168 #endif /* !_SYS_TASKQUEUE_H_ */