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
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
#![unstable(reason = "not public", issue = "none", feature = "fd")]
use crate::cmp;
use crate::io::{self, Initializer, IoSlice, IoSliceMut, Read};
use crate::mem;
use crate::sys::cvt;
use crate::sys_common::AsInner;
use libc::{self, c_int, c_void, ssize_t};
#[derive(Debug)]
pub struct FileDesc {
fd: c_int,
}
fn max_len() -> usize {
// The maximum read limit on most posix-like systems is `SSIZE_MAX`,
// with the man page quoting that if the count of bytes to read is
// greater than `SSIZE_MAX` the result is "unspecified".
<ssize_t>::max_value() as usize
}
impl FileDesc {
pub fn new(fd: c_int) -> FileDesc {
FileDesc { fd: fd }
}
pub fn raw(&self) -> c_int {
self.fd
}
/// Extracts the actual filedescriptor without closing it.
pub fn into_raw(self) -> c_int {
let fd = self.fd;
mem::forget(self);
fd
}
pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
let ret = cvt(unsafe {
libc::read(self.fd, buf.as_mut_ptr() as *mut c_void, cmp::min(buf.len(), max_len()))
})?;
Ok(ret as usize)
}
pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
let ret = cvt(unsafe {
libc::readv(
self.fd,
bufs.as_ptr() as *const libc::iovec,
cmp::min(bufs.len(), c_int::max_value() as usize) as c_int,
)
})?;
Ok(ret as usize)
}
pub fn read_to_end(&self, buf: &mut Vec<u8>) -> io::Result<usize> {
let mut me = self;
(&mut me).read_to_end(buf)
}
pub fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
unsafe fn cvt_pread(
fd: c_int,
buf: *mut c_void,
count: usize,
offset: i64,
) -> io::Result<isize> {
use libc::pread;
cvt(pread(fd, buf, count, offset))
}
unsafe {
cvt_pread(
self.fd,
buf.as_mut_ptr() as *mut c_void,
cmp::min(buf.len(), max_len()),
offset as i64,
)
.map(|n| n as usize)
}
}
pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
let ret = cvt(unsafe {
libc::write(self.fd, buf.as_ptr() as *const c_void, cmp::min(buf.len(), max_len()))
})?;
Ok(ret as usize)
}
pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
let ret = cvt(unsafe {
libc::writev(
self.fd,
bufs.as_ptr() as *const libc::iovec,
cmp::min(bufs.len(), c_int::max_value() as usize) as c_int,
)
})?;
Ok(ret as usize)
}
pub fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
unsafe fn cvt_pwrite(
fd: c_int,
buf: *const c_void,
count: usize,
offset: i64,
) -> io::Result<isize> {
use libc::pwrite;
cvt(pwrite(fd, buf, count, offset))
}
unsafe {
cvt_pwrite(
self.fd,
buf.as_ptr() as *const c_void,
cmp::min(buf.len(), max_len()),
offset as i64,
)
.map(|n| n as usize)
}
}
pub fn get_cloexec(&self) -> io::Result<bool> {
unsafe { Ok((cvt(libc::fcntl(self.fd, libc::F_GETFD))? & libc::FD_CLOEXEC) != 0) }
}
pub fn set_cloexec(&self) -> io::Result<()> {
unsafe {
let previous = cvt(libc::fcntl(self.fd, libc::F_GETFD))?;
let new = previous | libc::FD_CLOEXEC;
if new != previous {
cvt(libc::fcntl(self.fd, libc::F_SETFD, new))?;
}
Ok(())
}
}
pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
unsafe {
let v = nonblocking as c_int;
cvt(libc::ioctl(self.fd, libc::FIONBIO, &v))?;
Ok(())
}
}
// refer to pxPipeDrv library documentation.
// VxWorks uses fcntl to set O_NONBLOCK to the pipes
pub fn set_nonblocking_pipe(&self, nonblocking: bool) -> io::Result<()> {
unsafe {
let mut flags = cvt(libc::fcntl(self.fd, libc::F_GETFL, 0))?;
flags = if nonblocking { flags | libc::O_NONBLOCK } else { flags & !libc::O_NONBLOCK };
cvt(libc::fcntl(self.fd, libc::F_SETFL, flags))?;
Ok(())
}
}
pub fn duplicate(&self) -> io::Result<FileDesc> {
let fd = self.raw();
match cvt(unsafe { libc::fcntl(fd, libc::F_DUPFD_CLOEXEC, 0) }) {
Ok(newfd) => Ok(FileDesc::new(newfd)),
Err(e) => return Err(e),
}
}
}
impl<'a> Read for &'a FileDesc {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
(**self).read(buf)
}
#[inline]
unsafe fn initializer(&self) -> Initializer {
Initializer::nop()
}
}
impl AsInner<c_int> for FileDesc {
fn as_inner(&self) -> &c_int {
&self.fd
}
}
impl Drop for FileDesc {
fn drop(&mut self) {
// Note that errors are ignored when closing a file descriptor. The
// reason for this is that if an error occurs we don't actually know if
// the file descriptor was closed or not, and if we retried (for
// something like EINTR), we might close another valid file descriptor
// (opened after we closed ours.
let _ = unsafe { libc::close(self.fd) };
}
}
|
