#ifndef __CLOCK_H_
#define __CLOCK_H_
/*
   clock.h

   If you wish to incorporate preemption into your project, you will
   need the following routines.

   Tian Lim	1/26/96

   last modified 4/7/96
                 8/8/96 (sungeun)
               10/13/97 (Neal Cardwell)
   
   */

#include <sys/time.h>
#include <signal.h>

/* ClockHandler is a ptr to a function such as "void clkhndlr(void)". */
typedef 	void (*ClockHandler) ();

/*
   PERIOD is the clock period in microseconds.  It is the interval at
   which clock ticks will be sent
   */
#define		PERIOD	500

/* Are interrupts enabled? */
typedef int boolean_t;
extern boolean_t interrupts;		/* this is defined in clock.c */
#define ENABLED 	1
#define DISABLED 	0


/* routines to set the interrupts flag */
extern void enable_interrupts();
extern void disable_interrupts();

/* minithread_clock_init
 * installs your clock interrupt service routine h.
 * h will be called every PERIOD microseconds (defined above).
 * interrupts are disabled by default.  After you enable interrupts
 * then your handler will be called automatically on every clock tick.
 */
extern void minithread_clock_init(ClockHandler h);

#endif  __CLOCK_H_