text: /*-
   * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
   * Copyright (c) 1994 by Chris Provenzano, proven@mit.edu
   * 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. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *  This product includes software developed by Chris Provenzano.
   * 4. The name of Chris Provenzano may not be used to endorse or promote
   *    products derived from this software without specific prior written
   *    permission.
   *
   * THIS SOFTWARE IS PROVIDED BY CHRIS PROVENZANO ``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 CHRIS PROVENZANO 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: src/sys/sys/timers.h,v 1.11 2006/03/01 06:48:31 davidxu Exp $
   *
   * Description : Basic timers header.
   */
  
  #ifndef _SYS_TIMERS_H_
  #define _SYS_TIMERS_H_
  
  #include <sys/time.h>
  
  #ifdef _KERNEL
  /*
   * Structures used to manage POSIX timers in a process.
   */
  struct itimer {
  	struct mtx  		it_mtx;
  	struct sigevent		it_sigev;
  	struct itimerspec	it_time;
  	struct proc 		*it_proc;
  	int	it_flags;
  	int	it_usecount;
  	int	it_overrun;		/* Overruns currently accumulating */
  	int	it_overrun_last;	/* Overruns associated w/ a delivery */
  	int	it_clockid;
  	int	it_timerid;
  	ksiginfo_t	it_ksi;
  	union {
  		/* realtime */
  		struct {
  			struct callout it_callout;
  		} _rt;
  
  		/* cpu timer */
  		struct {
  			LIST_ENTRY(itimer)	it_link;
  			TAILQ_ENTRY(itimer)	it_worklink;
  			int			it_active;
  			int			it_cflags;
  		} _cpu;
  	} _data;
  };
  
  #define it_callout	_data._rt.it_callout
  #define it_link		_data._cpu.it_link
  #define it_active	_data._cpu.it_active
  #define	it_worklink	_data._cpu.it_worklink
  #define	it_cflags	_data._cpu.it_cflags
  
  #define	ITF_DELETING	0x01
  #define	ITF_WANTED	0x02
  
  #define	ITCF_ONWORKLIST	0x01
  
  #define	TIMER_MAX	32
  
  #define	ITIMER_LOCK(it)		mtx_lock(&(it)->it_mtx)
  #define	ITIMER_UNLOCK(it)	mtx_unlock(&(it)->it_mtx)
  
  LIST_HEAD(itimerlist, itimer);
  
  struct	itimers {
  	struct itimerlist	its_virtual;
  	struct itimerlist	its_prof;
  	TAILQ_HEAD(, itimer)	its_worklist;
  	struct itimer		*its_timers[TIMER_MAX];
  };
  
  struct	kclock {
  	int (*timer_create)(struct itimer *timer);
  	int (*timer_settime)(struct itimer * timer, int flags,
  		struct itimerspec * new_value,
  		struct itimerspec * old_value);
  	int (*timer_delete)(struct itimer * timer);
  	int (*timer_gettime)(struct itimer * timer,
  		struct itimerspec * cur_value);
  	void (*event_hook)(struct proc *p, clockid_t clock_id, int event);
  };
  
  /* Event values for event_hook() */
  #define	ITIMER_EV_EXEC	0
  #define	ITIMER_EV_EXIT	1
  
  int	itimer_accept(struct proc *p, int tid, ksiginfo_t *ksi);
  #endif
  #endif /* !_SYS_TIMERS_H_ */
  