/*-
* Copyright (c) 2000 Doug Rabson
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _SYS_TASKQUEUE_H_
#define _SYS_TASKQUEUE_H_
#ifndef _KERNEL
#error "no user-servicable parts inside"
#endif
#include <sys/queue.h>
struct taskqueue;
/*
* Each task includes a function which is called from
* taskqueue_run(). The first argument is taken from the 'ta_context'
* field of struct task and the second argument is a count of how many
* times the task was enqueued before the call to taskqueue_run().
*/
typedef void task_fn_t(void *context, int pending);
/*
* A notification callback function which is called from
* taskqueue_enqueue(). The context argument is given in the call to
* taskqueue_create(). This function would normally be used to allow the
* queue to arrange to run itself later (e.g., by scheduling a software
* interrupt or waking a kernel thread).
*/
typedef void (*taskqueue_enqueue_fn)(void *context);
struct task {
STAILQ_ENTRY(task) ta_link; /* link for queue */
int ta_pending; /* count times queued */
int ta_priority; /* priority of task in queue */
task_fn_t *ta_func; /* task handler */
void *ta_context; /* argument for handler */
};
struct taskqueue *taskqueue_create(const char *name, int mflags,
taskqueue_enqueue_fn enqueue,
void *context);
int taskqueue_enqueue(struct taskqueue *queue, struct task *task);
struct taskqueue *taskqueue_find(const char *name);
void taskqueue_free(struct taskqueue *queue);
void taskqueue_run(struct taskqueue *queue);
/*
* Initialise a task structure.
*/
#define TASK_INIT(task, priority, func, context) do { \
(task)->ta_pending = 0; \
(task)->ta_priority = (priority); \
(task)->ta_func = (func); \
(task)->ta_context = (context); \
} while (0)
/*
* Declare a reference to a taskqueue.
*/
#define TASKQUEUE_DECLARE(name) \
extern struct taskqueue *taskqueue_##name
/*
* Define and initialise a taskqueue.
*/
#define TASKQUEUE_DEFINE(name, enqueue, context, init) \
\
struct taskqueue *taskqueue_##name; \
\
static void \
taskqueue_define_##name(void *arg) \
{ \
taskqueue_##name = \
taskqueue_create(#name, M_NOWAIT, (enqueue), (context)); \
init; \
} \
\
SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND, \
taskqueue_define_##name, NULL) \
\
struct __hack
/*
* This queue is serviced by a software interrupt handler. To enqueue
* a task, call taskqueue_enqueue(taskqueue_swi, &task).
*/
TASKQUEUE_DECLARE(swi);
#endif /* !_SYS_TASKQUEUE_H_ */
