1 /* Copyright (C) 2000-2022 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public License as
6    published by the Free Software Foundation; either version 2.1 of the
7    License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; see the file COPYING.LIB.  If
16    not, see <https://www.gnu.org/licenses/>.  */
17 
18 #include <errno.h>
19 #include <pthread.h>
20 #include <time.h>
21 
22 #include "posix-timer.h"
23 
24 
25 /* Get current value of timer TIMERID and store it in VLAUE.  */
26 int
timer_gettime(timer_t timerid,struct itimerspec * value)27 timer_gettime (timer_t timerid, struct itimerspec *value)
28 {
29   struct timer_node *timer;
30   struct timespec now, expiry;
31   int retval = -1, armed = 0, valid;
32   clock_t clock = 0;
33 
34   pthread_mutex_lock (&__timer_mutex);
35 
36   timer = timer_id2ptr (timerid);
37   valid = timer_valid (timer);
38 
39   if (valid) {
40     armed = timer->armed;
41     expiry = timer->expirytime;
42     clock = timer->clock;
43     value->it_interval = timer->value.it_interval;
44   }
45 
46   pthread_mutex_unlock (&__timer_mutex);
47 
48   if (valid)
49     {
50       if (armed)
51 	{
52 	  __clock_gettime (clock, &now);
53 	  if (timespec_compare (&now, &expiry) < 0)
54 	    timespec_sub (&value->it_value, &expiry, &now);
55 	  else
56 	    {
57 	      value->it_value.tv_sec = 0;
58 	      value->it_value.tv_nsec = 0;
59 	    }
60 	}
61       else
62 	{
63 	  value->it_value.tv_sec = 0;
64 	  value->it_value.tv_nsec = 0;
65 	}
66 
67       retval = 0;
68     }
69   else
70     __set_errno (EINVAL);
71 
72   return retval;
73 }
74