linuxthreads/sysdeps/pthread/timer_gettime.c

   1 /* Copyright (C) 2000, 2004 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Kaz Kylheku <kaz@ashi.footprints.net>.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <errno.h>
  21 #include <pthread.h>
  22 #include <time.h>
  23
  24 #include "posix-timer.h"
  25
  26
  27 /* Get current value of timer TIMERID and store it in VLAUE.  */
  28 int
  29 timer_gettime (timerid, value)
  30      timer_t timerid;
  31      struct itimerspec *value;
  32 {
  33   struct timer_node *timer;
  34   struct timespec now, expiry;
  35   int retval = -1, armed = 0, valid;
  36   clock_t clock = 0;
  37
  38   pthread_mutex_lock (&__timer_mutex);
  39
  40   timer = timer_id2ptr (timerid);
  41   valid = timer_valid (timer);
  42
  43   if (valid) {
  44     armed = timer->armed;
  45     expiry = timer->expirytime;
  46     clock = timer->clock;
  47     value->it_interval = timer->value.it_interval;
  48   }
  49
  50   pthread_mutex_unlock (&__timer_mutex);
  51
  52   if (valid)
  53     {
  54       if (armed)
  55         {
  56           clock_gettime (clock, &now);
  57           if (timespec_compare (&now, &expiry) < 0)
  58             timespec_sub (&value->it_value, &expiry, &now);
  59           else
  60             {
  61               value->it_value.tv_sec = 0;
  62               value->it_value.tv_nsec = 0;
  63             }
  64         }
  65       else
  66         {
  67           value->it_value.tv_sec = 0;
  68           value->it_value.tv_nsec = 0;
  69         }
  70
  71       retval = 0;
  72     }
  73   else
  74     __set_errno (EINVAL);
  75
  76   return retval;
  77 }