#ifndef _linux_POSIX_TIMERS_H
  #define _linux_POSIX_TIMERS_H
  
  #include <linux/spinlock.h>
  #include <linux/list.h>
  #include <linux/sched.h>
  
  union cpu_time_count {
  	cputime_t cpu;
  	unsigned long long sched;
  };
  
  struct cpu_timer_list {
  	struct list_head entry;
  	union cpu_time_count expires, incr;
  	struct task_struct *task;
  	int firing;
  };
  
  #define CPUCLOCK_PID(clock)		((pid_t) ~((clock) >> 3))
  #define CPUCLOCK_PERTHREAD(clock) \
  	(((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)
  #define CPUCLOCK_PID_MASK	7
  #define CPUCLOCK_PERTHREAD_MASK	4
  #define CPUCLOCK_WHICH(clock)	((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK)
  #define CPUCLOCK_CLOCK_MASK	3
  #define CPUCLOCK_PROF		0
  #define CPUCLOCK_VIRT		1
  #define CPUCLOCK_SCHED		2
  #define CPUCLOCK_MAX		3
  
  #define MAKE_PROCESS_CPUCLOCK(pid, clock) \
  	((~(clockid_t) (pid) << 3) | (clockid_t) (clock))
  #define MAKE_THREAD_CPUCLOCK(tid, clock) \
  	MAKE_PROCESS_CPUCLOCK((tid), (clock) | CPUCLOCK_PERTHREAD_MASK)
  
  /* POSIX.1b interval timer structure. */
  struct k_itimer {
  	struct list_head list;		/* free/ allocate list */
  	spinlock_t it_lock;
  	clockid_t it_clock;		/* which timer type */
  	timer_t it_id;			/* timer id */
  	int it_overrun;			/* overrun on pending signal  */
  	int it_overrun_last;		/* overrun on last delivered signal */

  	int it_requeue_pending;		/* waiting to requeue this timer */

  #define REQUEUE_PENDING 1
  	int it_sigev_notify;		/* notify word of sigevent struct */
  	int it_sigev_signo;		/* signo word of sigevent struct */
  	sigval_t it_sigev_value;	/* value word of sigevent struct */
  	struct task_struct *it_process;	/* process to send signal to */
  	struct sigqueue *sigq;		/* signal queue entry. */
  	union {
  		struct {

  			struct hrtimer timer;
  			ktime_t interval;

  		} real;
  		struct cpu_timer_list cpu;
  		struct {
  			unsigned int clock;
  			unsigned int node;
  			unsigned long incr;
  			unsigned long expires;
  		} mmtimer;
  	} it;
  };

  struct k_clock {

  	int res;		/* in nanoseconds */

  	int (*clock_getres) (const clockid_t which_clock, struct timespec *tp);

  	int (*clock_set) (const clockid_t which_clock, struct timespec * tp);
  	int (*clock_get) (const clockid_t which_clock, struct timespec * tp);

  	int (*timer_create) (struct k_itimer *timer);

  	int (*nsleep) (const clockid_t which_clock, int flags,

  		       struct timespec *, struct timespec __user *);

  	long (*nsleep_restart) (struct restart_block *restart_block);

  	int (*timer_set) (struct k_itimer * timr, int flags,
  			  struct itimerspec * new_setting,
  			  struct itimerspec * old_setting);
  	int (*timer_del) (struct k_itimer * timr);
  #define TIMER_RETRY 1
  	void (*timer_get) (struct k_itimer * timr,
  			   struct itimerspec * cur_setting);
  };

  void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock);

  /* error handlers for timer_create, nanosleep and settime */

  int do_posix_clock_nonanosleep(const clockid_t, int flags, struct timespec *,
  			       struct timespec __user *);

  int do_posix_clock_nosettime(const clockid_t, struct timespec *tp);

  
  /* function to call to trigger timer event */
  int posix_timer_event(struct k_itimer *timr, int si_private);

  int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *ts);
  int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *ts);
  int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *ts);
  int posix_cpu_timer_create(struct k_itimer *timer);
  int posix_cpu_nsleep(const clockid_t which_clock, int flags,

  		     struct timespec *rqtp, struct timespec __user *rmtp);

  long posix_cpu_nsleep_restart(struct restart_block *restart_block);

  int posix_cpu_timer_set(struct k_itimer *timer, int flags,
  			struct itimerspec *new, struct itimerspec *old);
  int posix_cpu_timer_del(struct k_itimer *timer);
  void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp);
  
  void posix_cpu_timer_schedule(struct k_itimer *timer);
  
  void run_posix_cpu_timers(struct task_struct *task);
  void posix_cpu_timers_exit(struct task_struct *task);
  void posix_cpu_timers_exit_group(struct task_struct *task);
  
  void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,
  			   cputime_t *newval, cputime_t *oldval);

  long clock_nanosleep_restart(struct restart_block *restart_block);

  #endif