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      1 /*	$NetBSD: callout.h,v 1.22 2005/12/11 12:25:20 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2000, 2003 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
      9  * NASA Ames Research Center.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *	This product includes software developed by the NetBSD
     22  *	Foundation, Inc. and its contributors.
     23  * 4. Neither the name of The NetBSD Foundation nor the names of its
     24  *    contributors may be used to endorse or promote products derived
     25  *    from this software without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     37  * POSSIBILITY OF SUCH DAMAGE.
     38  */
     39 
     40 /*
     41  * Copyright (c) 2000-2001 Artur Grabowski <art (at) openbsd.org>
     42  * All rights reserved.
     43  *
     44  * Redistribution and use in source and binary forms, with or without
     45  * modification, are permitted provided that the following conditions
     46  * are met:
     47  *
     48  * 1. Redistributions of source code must retain the above copyright
     49  *    notice, this list of conditions and the following disclaimer.
     50  * 2. Redistributions in binary form must reproduce the above copyright
     51  *    notice, this list of conditions and the following disclaimer in the
     52  *    documentation and/or other materials provided with the distribution.
     53  * 3. The name of the author may not be used to endorse or promote products
     54  *    derived from this software without specific prior written permission.
     55  *
     56  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
     57  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
     58  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
     59  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     60  * EXEMPLARY, OR CONSEQUENTIAL  DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     61  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     62  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     63  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     64  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     65  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     66  */
     67 
     68 #ifndef _SYS_CALLOUT_H_
     69 #define _SYS_CALLOUT_H_
     70 
     71 /*
     72  * The following funkyness is to appease gcc3's strict aliasing.
     73  */
     74 struct callout;
     75 struct callout_circq {
     76 	/* next element */
     77 	union {
     78 		struct callout		*elem;
     79 		struct callout_circq	*list;
     80 	} cq_next;
     81 	/* previous element */
     82 	union {
     83 		struct callout		*elem;
     84 		struct callout_circq	*list;
     85 	} cq_prev;
     86 };
     87 #define	cq_next_e	cq_next.elem
     88 #define	cq_prev_e	cq_prev.elem
     89 #define	cq_next_l	cq_next.list
     90 #define	cq_prev_l	cq_prev.list
     91 
     92 struct callout {
     93 	struct callout_circq c_list;		/* linkage on queue */
     94 	void	(*c_func)(void *);		/* function to call */
     95 	void	*c_arg;				/* function argument */
     96 	int	c_time;				/* when callout fires */
     97 	int	c_flags;			/* state of this entry */
     98 };
     99 
    100 #define	CALLOUT_PENDING		0x0002	/* callout is on the queue */
    101 #define	CALLOUT_FIRED		0x0004	/* callout has fired */
    102 #define	CALLOUT_INVOKING	0x0008	/* callout function is being invoked */
    103 
    104 #define	CALLOUT_INITIALIZER_SETFUNC(func, arg)				\
    105 				{ {{NULL}, {NULL}}, func, arg, 0, 0 }
    106 
    107 #define	CALLOUT_INITIALIZER	CALLOUT_INITIALIZER_SETFUNC(NULL, NULL)
    108 
    109 #ifdef _KERNEL
    110 void	callout_startup(void);
    111 void	callout_init(struct callout *);
    112 void	callout_setfunc(struct callout *, void (*)(void *), void *);
    113 void	callout_reset(struct callout *, int, void (*)(void *), void *);
    114 void	callout_schedule(struct callout *, int);
    115 void	callout_stop(struct callout *);
    116 int	callout_hardclock(void);
    117 
    118 #define	callout_setfunc(c, f, a)					\
    119 do {									\
    120 	(c)->c_func = (f);						\
    121 	(c)->c_arg = (a);						\
    122 } while (/*CONSTCOND*/0)
    123 
    124 #define	callout_pending(c)	((c)->c_flags & CALLOUT_PENDING)
    125 #define	callout_expired(c)	((c)->c_flags & CALLOUT_FIRED)
    126 #define	callout_active(c)	((c)->c_flags & (CALLOUT_PENDING|CALLOUT_FIRED))
    127 #define	callout_invoking(c)	((c)->c_flags & CALLOUT_INVOKING)
    128 #define	callout_ack(c)		((c)->c_flags &= ~CALLOUT_INVOKING)
    129 #endif /* _KERNEL */
    130 
    131 #endif /* !_SYS_CALLOUT_H_ */
    132