sysdeps/unix/sysv/linux/preadv.c

   1 /* Copyright (C) 2009-2017 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 <sys/uio.h>
  19 #include <sysdep-cancel.h>
  20
  21 #ifndef __OFF_T_MATCHES_OFF64_T
  22
  23 # ifdef __ASSUME_PREADV
  24
  25 #  ifndef __NR_preadv
  26 #   define __NR_preadv __NR_preadv64
  27 #  endif
  28
  29 ssize_t
  30 preadv (int fd, const struct iovec *vector, int count, off_t offset)
  31 {
  32   return SYSCALL_CANCEL (preadv, fd, vector, count, LO_HI_LONG (offset));
  33 }
  34 # else
  35 static ssize_t __atomic_preadv_replacement (int, const struct iovec *,
  36                                             int, off_t) internal_function;
  37 ssize_t
  38 preadv (int fd, const struct iovec *vector, int count, off_t offset)
  39 {
  40 #  ifdef __NR_preadv
  41   ssize_t result = SYSCALL_CANCEL (preadv, fd, vector, count,
  42                                    LO_HI_LONG (offset));
  43   if (result >= 0 || errno != ENOSYS)
  44     return result;
  45 #  endif
  46   return __atomic_preadv_replacement (fd, vector, count, offset);
  47 }
  48 #  define PREADV static internal_function __atomic_preadv_replacement
  49 #  define PREAD __pread
  50 #  define OFF_T off_t
  51 #  include <sysdeps/posix/preadv.c>
  52 # endif /* __ASSUME_PREADV  */
  53 #endif