Include/sys/callout.h

	callout.h revision 4fd606d1f5abe38e1f42c38de1d2e895166bd0f4
/*  $NetBSD: callout.h,v 1.22 2005/12/11 12:25:20 christos Exp $    */

/*-
 * Copyright (c) 2000, 2003 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
 * NASA Ames Research Center.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *  This product includes software developed by the NetBSD
 *  Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * 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.
 */

/*
 * Copyright (c) 2000-2001 Artur Grabowski <art@openbsd.org>
 * 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.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``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 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_CALLOUT_H_
#define _SYS_CALLOUT_H_

/*
 * The following funkyness is to appease gcc3's strict aliasing.
 */
struct callout;
struct callout_circq {
    /* next element */
    union {
        struct callout      *elem;
        struct callout_circq    *list;
    } cq_next;
    /* previous element */
    union {
        struct callout      *elem;
        struct callout_circq    *list;
    } cq_prev;
};
#define cq_next_e   cq_next.elem
#define cq_prev_e   cq_prev.elem
#define cq_next_l   cq_next.list
#define cq_prev_l   cq_prev.list

struct callout {
    struct callout_circq c_list;        /* linkage on queue */
    void    (*c_func)(void *);      /* function to call */
    void    *c_arg;             /* function argument */
    int c_time;             /* when callout fires */
    int c_flags;            /* state of this entry */
};

#define CALLOUT_PENDING     0x0002  /* callout is on the queue */
#define CALLOUT_FIRED       0x0004  /* callout has fired */
#define CALLOUT_INVOKING    0x0008  /* callout function is being invoked */

#define CALLOUT_INITIALIZER_SETFUNC(func, arg)              \
                { {{NULL}, {NULL}}, func, arg, 0, 0 }

#define CALLOUT_INITIALIZER CALLOUT_INITIALIZER_SETFUNC(NULL, NULL)

#ifdef _KERNEL
void    callout_startup(void);
void    callout_init(struct callout *);
void    callout_setfunc(struct callout *, void (*)(void *), void *);
void    callout_reset(struct callout *, int, void (*)(void *), void *);
void    callout_schedule(struct callout *, int);
void    callout_stop(struct callout *);
int callout_hardclock(void);

#define callout_setfunc(c, f, a)                    \
do {                                    \
    (c)->c_func = (f);                      \
    (c)->c_arg = (a);                       \
} while (/*CONSTCOND*/0)

#define callout_pending(c)  ((c)->c_flags & CALLOUT_PENDING)
#define callout_expired(c)  ((c)->c_flags & CALLOUT_FIRED)
#define callout_active(c)   ((c)->c_flags & (CALLOUT_PENDING|CALLOUT_FIRED))
#define callout_invoking(c) ((c)->c_flags & CALLOUT_INVOKING)
#define callout_ack(c)      ((c)->c_flags &= ~CALLOUT_INVOKING)
#endif /* _KERNEL */

#endif /* !_SYS_CALLOUT_H_ */