/* Copyright (C) 2000, 2001 Free Software Foundation, Inc.   This file is part of the GNU C Library.   Contributed by Kaz Kylheku <kaz@ashi.footprints.net>.   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; see the file COPYING.LIB.  If not,   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,   Boston, MA 02111-1307, USA.  */#include <errno.h>#include <pthread.h>#include <time.h>#include "posix-timer.h"/* Set timer TIMERID to VALUE, returning old value in OVLAUE.  */inttimer_settime (timerid, flags, value, ovalue)     timer_t timerid;     int flags;     const struct itimerspec *value;     struct itimerspec *ovalue;{  struct timer_node *timer;  struct thread_node *thread = NULL;  struct timespec now;  int have_now = 0, need_wakeup = 0;  int retval = -1;  timer = timer_id2ptr (timerid);  if (timer == NULL)    {      __set_errno (EINVAL);      goto bail;    }  if (value->it_interval.tv_nsec < 0      || value->it_interval.tv_nsec >= 1000000000      || value->it_value.tv_nsec < 0      || value->it_value.tv_nsec >= 1000000000)    {      __set_errno (EINVAL);      goto bail;    }  /* Will need to know current time since this is a relative timer;     might as well make the system call outside of the lock now! */  if ((flags & TIMER_ABSTIME) == 0)    {      clock_gettime (timer->clock, &now);      have_now = 1;    }  pthread_mutex_lock (&__timer_mutex);  timer_addref (timer);  /* One final check of timer validity; this one is possible only     until we have the mutex, because it accesses the inuse flag. */  if (! timer_valid(timer))    {      __set_errno (EINVAL);      goto unlock_bail;    }  if (ovalue != NULL)    {      ovalue->it_interval = timer->value.it_interval;      if (timer->armed)	{	  if (! have_now)	    {	      pthread_mutex_unlock (&__timer_mutex);	      clock_gettime (timer->clock, &now);	      have_now = 1;	      pthread_mutex_lock (&__timer_mutex);	      timer_addref (timer);	    }	  timespec_sub (&ovalue->it_value, &timer->expirytime, &now);	}      else	{	  ovalue->it_value.tv_sec = 0;	  ovalue->it_value.tv_nsec = 0;	}    }  timer->value = *value;  list_unlink_ip (&timer->links);  timer->armed = 0;  thread = timer->thread;  /* A value of { 0, 0 } causes the timer to be stopped. */  if (value->it_value.tv_sec != 0      || __builtin_expect (value->it_value.tv_nsec != 0, 1))    {      if ((flags & TIMER_ABSTIME) != 0)	/* The user specified the expiration time.  */	timer->expirytime = value->it_value;      else	timespec_add (&timer->expirytime, &now, &value->it_value);      /* Only need to wake up the thread if timer is inserted	 at the head of the queue. */      if (thread != NULL)	need_wakeup = __timer_thread_queue_timer (thread, timer);      timer->armed = 1;    }  retval = 0;unlock_bail:  timer_delref (timer);  pthread_mutex_unlock (&__timer_mutex);bail:  if (thread != NULL && need_wakeup)    __timer_thread_wakeup (thread);  return retval;}