1 /* writev supports all Linux kernels >= 2.0.
2 Copyright (C) 1997-2014 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
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 <http://www.gnu.org/licenses/>. */
21 #include <sys/param.h>
24 #include <sysdep-cancel.h>
25 #include <sys/syscall.h>
26 #include <kernel-features.h>
28 #ifndef __ASSUME_COMPLETE_READV_WRITEV
29 static ssize_t
__atomic_writev_replacement (int, const struct iovec
*,
30 int) internal_function
;
34 /* Not all versions of the kernel support the large number of records. */
36 # define UIO_FASTIOV 8 /* 8 is a safe number. */
41 __libc_writev (fd
, vector
, count
)
43 const struct iovec
*vector
;
49 result
= INLINE_SYSCALL (writev
, 3, fd
, vector
, count
);
52 int oldtype
= LIBC_CANCEL_ASYNC ();
54 result
= INLINE_SYSCALL (writev
, 3, fd
, vector
, count
);
56 LIBC_CANCEL_RESET (oldtype
);
59 #ifdef __ASSUME_COMPLETE_READV_WRITEV
62 if (result
>= 0 || errno
!= EINVAL
|| count
<= UIO_FASTIOV
)
65 return __atomic_writev_replacement (fd
, vector
, count
);
68 strong_alias (__libc_writev
, __writev
)
69 weak_alias (__libc_writev
, writev
)
71 #ifndef __ASSUME_COMPLETE_READV_WRITEV
72 # define __libc_writev static internal_function __atomic_writev_replacement
73 # include <sysdeps/posix/writev.c>