nptl/sysdeps/pthread/timer_gettime.c

   1 /* Copyright (C) 2000-2014 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
  17    not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <pthread.h>
  21 #include <time.h>
  22
  23 #include "posix-timer.h"
  24
  25
  26 /* Get current value of timer TIMERID and store it in VLAUE.  */
  27 int
  28 timer_gettime (timerid, value)
  29      timer_t timerid;
  30      struct itimerspec *value;
  31 {
  32   struct timer_node *timer;
  33   struct timespec now, expiry;
  34   int retval = -1, armed = 0, valid;
  35   clock_t clock = 0;
  36
  37   pthread_mutex_lock (&__timer_mutex);
  38
  39   timer = timer_id2ptr (timerid);
  40   valid = timer_valid (timer);
  41
  42   if (valid) {
  43     armed = timer->armed;
  44     expiry = timer->expirytime;
  45     clock = timer->clock;
  46     value->it_interval = timer->value.it_interval;
  47   }
  48
  49   pthread_mutex_unlock (&__timer_mutex);
  50
  51   if (valid)
  52     {
  53       if (armed)
  54         {
  55           clock_gettime (clock, &now);
  56           if (timespec_compare (&now, &expiry) < 0)
  57             timespec_sub (&value->it_value, &expiry, &now);
  58           else
  59             {
  60               value->it_value.tv_sec = 0;
  61               value->it_value.tv_nsec = 0;
  62             }
  63         }
  64       else
  65         {
  66           value->it_value.tv_sec = 0;
  67           value->it_value.tv_nsec = 0;
  68         }
  69
  70       retval = 0;
  71     }
  72   else
  73     __set_errno (EINVAL);
  74
  75   return retval;
  76 }