#ifndef TIMER_H
#define TIMER_H
/*
 * ----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <address@hidden> wrote this file.  As long as you retain this notice you
 * can do whatever you want with this stuff. If we meet some day, and you think
 * this stuff is worth it, you can buy me a beer in return.        Joerg Wunsch
 * ----------------------------------------------------------------------------
 *
 * Simple timer queue management
 *
 * $Id: timer.h,v 1.1.1.1 2002/04/14 20:01:36 j Exp $
 */

/* argument to pass to an action function */
union timeoutarg
{
  uint16_t i;
  void *p;
};

/* the action function itself */
typedef void (*timeout_t)(union timeoutarg);
/* we maintain a 32-bit clock */
typedef uint32_t time_t;

/*
 * Insert one-shot timer `tm' ticks after now.  Call `fun'
 * with `arg' when timer expires.
 *
 * Returns handle to timer queue entry that can be saved for
 * later deletion of the event.  Returns 0 if fails (no more
 * memory for allocating a timer).
 */
void *timeout(time_t tm, timeout_t fun, union timeoutarg arg);

/*
 * Delete the timer handle from the queue.  Returns 0 for
 * success, -1 if event was not found in queue.
 */
int untimeout(void *handle);

/*
 * Must be called per hardware timer tick from main().  Should
 * not be called directly from within an interrupt service, since
 * the callback functions for expired timers will be called within
 * the context of timertick(), and since the queue handling has no
 * precautions against being interrupted.
 */
void timertick(void);

#endif /* TIMER_H */