/*	$NetBSD$	*/

/*-
 * Copyright (c) 2014 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Taylor R. Campbell.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#ifndef	_SYS_TASK_H_
#define	_SYS_TASK_H_

#include <sys/types.h>
#include <sys/callout.h>
#include <sys/mutex.h>
#include <sys/queue.h>

struct task;
struct taskqueue;
struct taskworker;

typedef void task_fn_t(struct task *);

struct task {
	struct taskworker	*volatile task_worker;
	task_fn_t		*task_fn;
	TAILQ_ENTRY(task)	task_entry;
};

struct delayed_task {
	struct task		dt_task;
	struct callout		dt_callout;
};

static inline struct delayed_task *
to_delayed_task(struct task *task)
{

	return container_of(task, struct delayed_task, dt_task);
}

#define	TASKQUEUE_PERCPU	0x01

void	tasks_init(void);

int	taskqueue_get(struct taskqueue **, pri_t);
void	taskqueue_put(struct taskqueue *);

int	taskqueue_create(struct taskqueue **, const char *, pri_t, int, int);
void	taskqueue_destroy(struct taskqueue *);

void	taskqueue_drain(struct taskqueue *);

static inline void
task_init(struct task *task, task_fn_t *fn)
{

	task->task_worker = NULL;
	task->task_fn = fn;
}

void	task_destroy(struct task *);

void	task_done(struct task *);

void	task_schedule(struct taskqueue *, struct task *);
bool	task_cancel(struct task *, kmutex_t *);
bool	task_cancel_async(struct task *);

/* Not part of the API -- don't use this outside delayed_task_init.  */
void	delayed_task_timeout(void *);

static inline void
delayed_task_init(struct delayed_task *dt, task_fn_t *fn)
{

	task_init(&dt->dt_task);
	callout_init(&dt->dt_callout, CALLOUT_MPSAFE);
	callout_setfunc(&dt->dt_callout, delayed_task_timeout, dt);
}

void	delayed_task_destroy(struct delayed_task *);

void	delayed_task_schedule_ticks(struct taskqueue *, struct delayed_task *,
	    int);
#if notyet
/* Once we have high-resolution timers, we should support them here.  */
void	delayed_task_schedule_nsec(struct taskqueue *, struct delayed_task *,
	    int32_t, uint32_t);
#endif
bool	delayed_task_cancel(struct delayed_task *, kmutex_t *);
bool	delayed_task_cancel_async(struct delayed_task *);

#endif	/* _SYS_TASK_H_ */