1 /* writev supports all Linux kernels >= 2.0.
2 Copyright (C) 1997-2013 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 <bp-checks.h>
27 #include <kernel-features.h>
29 #ifndef __ASSUME_COMPLETE_READV_WRITEV
30 static ssize_t __atomic_writev_replacement (int, const struct iovec *,
31 int) internal_function;
35 /* Not all versions of the kernel support the large number of records. */
37 # define UIO_FASTIOV 8 /* 8 is a safe number. */
42 __libc_writev (fd, vector, count)
44 const struct iovec *vector;
50 result = INLINE_SYSCALL (writev, 3, fd, CHECK_N (vector, count), count);
53 int oldtype = LIBC_CANCEL_ASYNC ();
55 result = INLINE_SYSCALL (writev, 3, fd, CHECK_N (vector, count), count);
57 LIBC_CANCEL_RESET (oldtype);
60 #ifdef __ASSUME_COMPLETE_READV_WRITEV
63 if (result >= 0 || errno != EINVAL || count <= UIO_FASTIOV)
66 return __atomic_writev_replacement (fd, vector, count);
69 strong_alias (__libc_writev, __writev)
70 weak_alias (__libc_writev, writev)
72 #ifndef __ASSUME_COMPLETE_READV_WRITEV
73 # define __libc_writev static internal_function __atomic_writev_replacement
74 # include <sysdeps/posix/writev.c>