librt/clock_nanosleep.c

   1 /* Copyright (C) 2003-2018 Free Software Foundation, Inc.
   2
   3    The GNU C Library is free software; you can redistribute it and/or
   4    modify it under the terms of the GNU Lesser General Public
   5    License as published by the Free Software Foundation; either
   6    version 2.1 of the License, or (at your option) any later version.
   7
   8    The GNU C Library is distributed in the hope that it will be useful,
   9    but WITHOUT ANY WARRANTY; without even the implied warranty of
  10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11    Lesser General Public License for more details.
  12
  13    You should have received a copy of the GNU Lesser General Public
  14    License along with the GNU C Library; if not, see
  15    <http://www.gnu.org/licenses/>.  */
  16
  17 #include <time.h>
  18 #include <errno.h>
  19 #include <cancel.h>
  20 #include <sys/syscall.h>
  21
  22 #include "kernel-posix-cpu-timers.h"
  23
  24
  25 /* We can simply use the syscall.  The CPU clocks are not supported
  26    with this function.  */
  27 int
  28 clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
  29                    struct timespec *rem)
  30 {
  31   INTERNAL_SYSCALL_DECL (err);
  32   int r;
  33
  34   if (clock_id == CLOCK_THREAD_CPUTIME_ID)
  35     return EINVAL;
  36   if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
  37     clock_id = MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED);
  38
  39   if (SINGLE_THREAD_P)
  40     r = INTERNAL_SYSCALL (clock_nanosleep, err, 4, clock_id, flags, req, rem);
  41   else
  42     {
  43       int oldstate = LIBC_CANCEL_ASYNC ();
  44
  45       r = INTERNAL_SYSCALL (clock_nanosleep, err, 4, clock_id, flags, req,
  46                             rem);
  47
  48       LIBC_CANCEL_RESET (oldstate);
  49     }
  50
  51   return (INTERNAL_SYSCALL_ERROR_P (r, err)
  52           ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
  53 }