sysdeps/unix/sysv/linux/clock_nanosleep.c

   1 /* Copyright (C) 2003-2019 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
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <time.h>
  19 #include <errno.h>
  20
  21 #include <sysdep-cancel.h>
  22 #include "kernel-posix-cpu-timers.h"
  23
  24 #include <shlib-compat.h>
  25
  26 /* We can simply use the syscall.  The CPU clocks are not supported
  27    with this function.  */
  28 int
  29 __clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
  30                    struct timespec *rem)
  31 {
  32   if (clock_id == CLOCK_THREAD_CPUTIME_ID)
  33     return EINVAL;
  34   if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
  35     clock_id = MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED);
  36
  37   /* If the call is interrupted by a signal handler or encounters an error,
  38      it returns a positive value similar to errno.  */
  39   INTERNAL_SYSCALL_DECL (err);
  40   int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
  41                                    req, rem);
  42   return (INTERNAL_SYSCALL_ERROR_P (r, err)
  43           ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
  44 }
  45
  46 versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, GLIBC_2_17);
  47 /* clock_nanosleep moved to libc in version 2.17;
  48    old binaries may expect the symbol version it had in librt.  */
  49 #if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17)
  50 strong_alias (__clock_nanosleep, __clock_nanosleep_2);
  51 compat_symbol (libc, __clock_nanosleep_2, clock_nanosleep, GLIBC_2_2);
  52 #endif