1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
/* readv supports all Linux kernels >= 2.0.
Copyright (C) 1997, 1998, 2000, 2002 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <stddef.h>
#include <sys/param.h>
#include <sys/uio.h>
#include <sysdep-cancel.h>
#include <sys/syscall.h>
#include <bp-checks.h>
extern ssize_t __syscall_readv (int, __const struct iovec *__unbounded, int);
static ssize_t __atomic_readv_replacement (int, __const struct iovec *,
int) internal_function;
/* Not all versions of the kernel support the large number of records. */
#ifndef UIO_FASTIOV
# define UIO_FASTIOV 8 /* 8 is a safe number. */
#endif
/* We should deal with kernel which have a smaller UIO_FASTIOV as well
as a very big count. */
static ssize_t
do_readv (fd, vector, count)
int fd;
const struct iovec *vector;
int count;
{
ssize_t bytes_read;
bytes_read = INLINE_SYSCALL (readv, 3, fd, CHECK_N (vector, count), count);
if (bytes_read >= 0 || errno != EINVAL || count <= UIO_FASTIOV)
return bytes_read;
return __atomic_readv_replacement (fd, vector, count);
}
ssize_t
__libc_readv (fd, vector, count)
int fd;
const struct iovec *vector;
int count;
{
if (SINGLE_THREAD_P)
return do_readv (fd, vector, count);
int oldtype = LIBC_CANCEL_ASYNC ();
int result = do_readv (fd, vector, count);
LIBC_CANCEL_RESET (oldtype);
return result;
}
strong_alias (__libc_readv, __readv)
weak_alias (__libc_readv, readv)
#define __libc_readv static internal_function __atomic_readv_replacement
#include <sysdeps/posix/readv.c>
|
