support/support_create_timer.c

   1 /* Create a periodic timer.
   2    Copyright (C) 2021-2022 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   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
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <support/check.h>
  20 #include <support/support.h>
  21 #include <support/xsignal.h>
  22 #include <time.h>
  23
  24 static void
  25 dummy_alrm_handler (int sig)
  26 {
  27 }
  28
  29 timer_t
  30 support_create_timer (uint64_t sec, long int nsec, bool repeat,
  31                       void (*callback)(int))
  32 {
  33   struct sigaction sa;
  34   sa.sa_handler = callback != NULL ? callback : dummy_alrm_handler;
  35   sigemptyset (&sa.sa_mask);
  36   sa.sa_flags = 0;
  37   xsigaction (SIGALRM, &sa, NULL);
  38
  39   struct sigevent ev = {
  40     .sigev_notify = SIGEV_SIGNAL,
  41     .sigev_signo = SIGALRM
  42   };
  43   timer_t timerid;
  44   int r = timer_create (CLOCK_REALTIME, &ev, &timerid);
  45   if (r == -1)
  46     FAIL_EXIT1 ("timer_create: %m");
  47
  48   /* Single timer with 0.1s.  */
  49   struct itimerspec its =
  50     {
  51       { .tv_sec = repeat ? sec : 0, .tv_nsec = repeat ? nsec : 0 },
  52       { .tv_sec = sec, .tv_nsec = nsec }
  53     };
  54   r = timer_settime (timerid, 0, &its, NULL);
  55   if (r == -1)
  56     FAIL_EXIT1 ("timer_settime: %m");
  57
  58   return timerid;
  59 }
  60
  61 /* Disable the timer TIMER.  */
  62 void
  63 support_delete_timer (timer_t timer)
  64 {
  65   int r = timer_delete (timer);
  66   if (r == -1)
  67     FAIL_EXIT1 ("timer_delete: %m");
  68   xsignal (SIGALRM, SIG_DFL);
  69 }