glibc/sysdeps/unix/sysv/linux/clock_nanosleep.c

/* Copyright (C) 2003-2019 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <time.h>
#include <errno.h>

#include <sysdep-cancel.h>
#include "kernel-posix-cpu-timers.h"

#include <shlib-compat.h>

/* We can simply use the syscall.  The CPU clocks are not supported
   with this function.  */
int
__clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
		   struct timespec *rem)
{
  if (clock_id == CLOCK_THREAD_CPUTIME_ID)
    return EINVAL;
  if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
    clock_id = MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED);

  /* If the call is interrupted by a signal handler or encounters an error,
     it returns a positive value similar to errno.  */
  INTERNAL_SYSCALL_DECL (err);
  int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
				   req, rem);
  return (INTERNAL_SYSCALL_ERROR_P (r, err)
	  ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
}

versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, GLIBC_2_17);
/* clock_nanosleep moved to libc in version 2.17;
   old binaries may expect the symbol version it had in librt.  */
#if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17)
strong_alias (__clock_nanosleep, __clock_nanosleep_2);
compat_symbol (libc, __clock_nanosleep_2, clock_nanosleep, GLIBC_2_2);
#endif