/* Copyright (C) 1994, 1995, 1997 Free Software Foundation, Inc.   This file is part of the GNU C Library.   The GNU C Library is free software; you can redistribute it and/or   modify it under the terms of the GNU Lesser General Public   License as published by the Free Software Foundation; either   version 2.1 of the License, or (at your option) any later version.   The GNU C Library is distributed in the hope that it will be useful,   but WITHOUT ANY WARRANTY; without even the implied warranty of   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU   Lesser General Public License for more details.   You should have received a copy of the GNU Lesser General Public   License along with the GNU C Library; if not, write to the Free   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA   02111-1307 USA.  */#include <stddef.h>#include <errno.h>#include <sys/time.h>#include <hurd.h>/* XXX Temporary cheezoid implementation; see __setitmr.c.  *//* These are defined in __setitmr.c.  */extern spin_lock_t _hurd_itimer_lock;extern struct itimerval _hurd_itimerval;extern struct timeval _hurd_itimer_started;static inline voidsubtract_timeval (struct timeval *from, const struct timeval *subtract){  from->tv_usec -= subtract->tv_usec;  from->tv_sec -= subtract->tv_sec;  while (from->tv_usec < 0)    {      --from->tv_sec;      from->tv_usec += 1000000;    }}/* Set *VALUE to the current setting of timer WHICH.   Return 0 on success, -1 on errors.  */int__getitimer (which, value)     enum __itimer_which which;     struct itimerval *value;{  struct itimerval val;  struct timeval elapsed;  switch (which)    {    default:      return __hurd_fail (EINVAL);    case ITIMER_VIRTUAL:    case ITIMER_PROF:      return __hurd_fail (ENOSYS);    case ITIMER_REAL:      break;    }  /* Get the time now.  */  if (__gettimeofday (&elapsed, NULL) < 0)    return -1;  /* Extract the current timer setting; and the time it was set, so we can     calculate the time elapsed so far.  */  HURD_CRITICAL_BEGIN;  __spin_lock (&_hurd_itimer_lock);  val = _hurd_itimerval;  subtract_timeval (&elapsed, &_hurd_itimer_started);  __spin_unlock (&_hurd_itimer_lock);  HURD_CRITICAL_END;  if ((val.it_value.tv_sec | val.it_value.tv_usec) != 0)    {      /* There is a pending alarm set.  VAL indicates the interval it was	 set for, relative to the time recorded in _hurd_itimer_started.	 Now compensate for the time elapsed since to get the user's	 conception of the current value of the timer (as if the value	 stored decreased every microsecond).  */      if (timercmp (&val.it_value, &elapsed, <))	{	  /* Hmm.  The timer should have just gone off, but has not been	     reset.  This is a possible timing glitch.  The alarm will signal	     soon, so fabricate a value for how soon.  */	  val.it_value.tv_sec = 0;	  val.it_value.tv_usec = 10; /* Random.  */	}      else	/* Subtract the time elapsed since the timer was set	   from the current timer value the user sees.  */	subtract_timeval (&val.it_value, &elapsed);    }  *value = val;  return 0;}weak_alias (__getitimer, getitimer)