Struct tokio::net::UnixStream
source · [−]pub struct UnixStream { /* private fields */ }
Expand description
A structure representing a connected Unix socket.
This socket can be connected directly with UnixStream::connect
or accepted
from a listener with UnixListener::incoming
. Additionally, a pair of
anonymous Unix sockets can be created with UnixStream::pair
.
To shut down the stream in the write direction, you can call the
shutdown()
method. This will cause the other peer to receive a read of
length 0, indicating that no more data will be sent. This only closes
the stream in one direction.
Implementations
sourceimpl UnixStream
impl UnixStream
sourcepub async fn connect<P>(path: P) -> Result<UnixStream> where
P: AsRef<Path>,
pub async fn connect<P>(path: P) -> Result<UnixStream> where
P: AsRef<Path>,
Connects to the socket named by path
.
This function will create a new Unix socket and connect to the path specified, associating the returned stream with the default event loop’s handle.
sourcepub async fn ready(&self, interest: Interest) -> Result<Ready>
pub async fn ready(&self, interest: Interest) -> Result<Ready>
Waits for any of the requested ready states.
This function is usually paired with try_read()
or try_write()
. It
can be used to concurrently read / write to the same socket on a single
task without splitting the socket.
Cancel safety
This method is cancel safe. Once a readiness event occurs, the method
will continue to return immediately until the readiness event is
consumed by an attempt to read or write that fails with WouldBlock
or
Poll::Pending
.
Examples
Concurrently read and write to the stream on the same task without splitting.
use tokio::io::Interest;
use tokio::net::UnixStream;
use std::error::Error;
use std::io;
#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
let dir = tempfile::tempdir().unwrap();
let bind_path = dir.path().join("bind_path");
let stream = UnixStream::connect(bind_path).await?;
loop {
let ready = stream.ready(Interest::READABLE | Interest::WRITABLE).await?;
if ready.is_readable() {
let mut data = vec![0; 1024];
// Try to read data, this may still fail with `WouldBlock`
// if the readiness event is a false positive.
match stream.try_read(&mut data) {
Ok(n) => {
println!("read {} bytes", n);
}
Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
continue;
}
Err(e) => {
return Err(e.into());
}
}
}
if ready.is_writable() {
// Try to write data, this may still fail with `WouldBlock`
// if the readiness event is a false positive.
match stream.try_write(b"hello world") {
Ok(n) => {
println!("write {} bytes", n);
}
Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
continue;
}
Err(e) => {
return Err(e.into());
}
}
}
}
}
sourcepub async fn readable(&self) -> Result<()>
pub async fn readable(&self) -> Result<()>
Waits for the socket to become readable.
This function is equivalent to ready(Interest::READABLE)
and is usually
paired with try_read()
.
Cancel safety
This method is cancel safe. Once a readiness event occurs, the method
will continue to return immediately until the readiness event is
consumed by an attempt to read that fails with WouldBlock
or
Poll::Pending
.
Examples
use tokio::net::UnixStream;
use std::error::Error;
use std::io;
#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
// Connect to a peer
let dir = tempfile::tempdir().unwrap();
let bind_path = dir.path().join("bind_path");
let stream = UnixStream::connect(bind_path).await?;
let mut msg = vec![0; 1024];
loop {
// Wait for the socket to be readable
stream.readable().await?;
// Try to read data, this may still fail with `WouldBlock`
// if the readiness event is a false positive.
match stream.try_read(&mut msg) {
Ok(n) => {
msg.truncate(n);
break;
}
Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
continue;
}
Err(e) => {
return Err(e.into());
}
}
}
println!("GOT = {:?}", msg);
Ok(())
}
sourcepub fn poll_read_ready(&self, cx: &mut Context<'_>) -> Poll<Result<()>>
pub fn poll_read_ready(&self, cx: &mut Context<'_>) -> Poll<Result<()>>
Polls for read readiness.
If the unix stream is not currently ready for reading, this method will
store a clone of the Waker
from the provided Context
. When the unix
stream becomes ready for reading, Waker::wake
will be called on the
waker.
Note that on multiple calls to poll_read_ready
or poll_read
, only
the Waker
from the Context
passed to the most recent call is
scheduled to receive a wakeup. (However, poll_write_ready
retains a
second, independent waker.)
This function is intended for cases where creating and pinning a future
via readable
is not feasible. Where possible, using readable
is
preferred, as this supports polling from multiple tasks at once.
Return value
The function returns:
Poll::Pending
if the unix stream is not ready for reading.Poll::Ready(Ok(()))
if the unix stream is ready for reading.Poll::Ready(Err(e))
if an error is encountered.
Errors
This function may encounter any standard I/O error except WouldBlock
.
sourcepub fn try_read(&self, buf: &mut [u8]) -> Result<usize>
pub fn try_read(&self, buf: &mut [u8]) -> Result<usize>
Try to read data from the stream into the provided buffer, returning how many bytes were read.
Receives any pending data from the socket but does not wait for new data
to arrive. On success, returns the number of bytes read. Because
try_read()
is non-blocking, the buffer does not have to be stored by
the async task and can exist entirely on the stack.
Usually, readable()
or ready()
is used with this function.
Return
If data is successfully read, Ok(n)
is returned, where n
is the
number of bytes read. Ok(0)
indicates the stream’s read half is closed
and will no longer yield data. If the stream is not ready to read data
Err(io::ErrorKind::WouldBlock)
is returned.
Examples
use tokio::net::UnixStream;
use std::error::Error;
use std::io;
#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
// Connect to a peer
let dir = tempfile::tempdir().unwrap();
let bind_path = dir.path().join("bind_path");
let stream = UnixStream::connect(bind_path).await?;
loop {
// Wait for the socket to be readable
stream.readable().await?;
// Creating the buffer **after** the `await` prevents it from
// being stored in the async task.
let mut buf = [0; 4096];
// Try to read data, this may still fail with `WouldBlock`
// if the readiness event is a false positive.
match stream.try_read(&mut buf) {
Ok(0) => break,
Ok(n) => {
println!("read {} bytes", n);
}
Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
continue;
}
Err(e) => {
return Err(e.into());
}
}
}
Ok(())
}
sourcepub fn try_read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize>
pub fn try_read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize>
Tries to read data from the stream into the provided buffers, returning how many bytes were read.
Data is copied to fill each buffer in order, with the final buffer
written to possibly being only partially filled. This method behaves
equivalently to a single call to try_read()
with concatenated
buffers.
Receives any pending data from the socket but does not wait for new data
to arrive. On success, returns the number of bytes read. Because
try_read_vectored()
is non-blocking, the buffer does not have to be
stored by the async task and can exist entirely on the stack.
Usually, readable()
or ready()
is used with this function.
Return
If data is successfully read, Ok(n)
is returned, where n
is the
number of bytes read. Ok(0)
indicates the stream’s read half is closed
and will no longer yield data. If the stream is not ready to read data
Err(io::ErrorKind::WouldBlock)
is returned.
Examples
use tokio::net::UnixStream;
use std::error::Error;
use std::io::{self, IoSliceMut};
#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
// Connect to a peer
let dir = tempfile::tempdir().unwrap();
let bind_path = dir.path().join("bind_path");
let stream = UnixStream::connect(bind_path).await?;
loop {
// Wait for the socket to be readable
stream.readable().await?;
// Creating the buffer **after** the `await` prevents it from
// being stored in the async task.
let mut buf_a = [0; 512];
let mut buf_b = [0; 1024];
let mut bufs = [
IoSliceMut::new(&mut buf_a),
IoSliceMut::new(&mut buf_b),
];
// Try to read data, this may still fail with `WouldBlock`
// if the readiness event is a false positive.
match stream.try_read_vectored(&mut bufs) {
Ok(0) => break,
Ok(n) => {
println!("read {} bytes", n);
}
Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
continue;
}
Err(e) => {
return Err(e.into());
}
}
}
Ok(())
}
sourcepub fn try_read_buf<B: BufMut>(&self, buf: &mut B) -> Result<usize>
pub fn try_read_buf<B: BufMut>(&self, buf: &mut B) -> Result<usize>
Tries to read data from the stream into the provided buffer, advancing the buffer’s internal cursor, returning how many bytes were read.
Receives any pending data from the socket but does not wait for new data
to arrive. On success, returns the number of bytes read. Because
try_read_buf()
is non-blocking, the buffer does not have to be stored by
the async task and can exist entirely on the stack.
Usually, readable()
or ready()
is used with this function.
Return
If data is successfully read, Ok(n)
is returned, where n
is the
number of bytes read. Ok(0)
indicates the stream’s read half is closed
and will no longer yield data. If the stream is not ready to read data
Err(io::ErrorKind::WouldBlock)
is returned.
Examples
use tokio::net::UnixStream;
use std::error::Error;
use std::io;
#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
// Connect to a peer
let dir = tempfile::tempdir().unwrap();
let bind_path = dir.path().join("bind_path");
let stream = UnixStream::connect(bind_path).await?;
loop {
// Wait for the socket to be readable
stream.readable().await?;
let mut buf = Vec::with_capacity(4096);
// Try to read data, this may still fail with `WouldBlock`
// if the readiness event is a false positive.
match stream.try_read_buf(&mut buf) {
Ok(0) => break,
Ok(n) => {
println!("read {} bytes", n);
}
Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
continue;
}
Err(e) => {
return Err(e.into());
}
}
}
Ok(())
}
sourcepub async fn writable(&self) -> Result<()>
pub async fn writable(&self) -> Result<()>
Waits for the socket to become writable.
This function is equivalent to ready(Interest::WRITABLE)
and is usually
paired with try_write()
.
Cancel safety
This method is cancel safe. Once a readiness event occurs, the method
will continue to return immediately until the readiness event is
consumed by an attempt to write that fails with WouldBlock
or
Poll::Pending
.
Examples
use tokio::net::UnixStream;
use std::error::Error;
use std::io;
#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
// Connect to a peer
let dir = tempfile::tempdir().unwrap();
let bind_path = dir.path().join("bind_path");
let stream = UnixStream::connect(bind_path).await?;
loop {
// Wait for the socket to be writable
stream.writable().await?;
// Try to write data, this may still fail with `WouldBlock`
// if the readiness event is a false positive.
match stream.try_write(b"hello world") {
Ok(n) => {
break;
}
Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
continue;
}
Err(e) => {
return Err(e.into());
}
}
}
Ok(())
}
sourcepub fn poll_write_ready(&self, cx: &mut Context<'_>) -> Poll<Result<()>>
pub fn poll_write_ready(&self, cx: &mut Context<'_>) -> Poll<Result<()>>
Polls for write readiness.
If the unix stream is not currently ready for writing, this method will
store a clone of the Waker
from the provided Context
. When the unix
stream becomes ready for writing, Waker::wake
will be called on the
waker.
Note that on multiple calls to poll_write_ready
or poll_write
, only
the Waker
from the Context
passed to the most recent call is
scheduled to receive a wakeup. (However, poll_read_ready
retains a
second, independent waker.)
This function is intended for cases where creating and pinning a future
via writable
is not feasible. Where possible, using writable
is
preferred, as this supports polling from multiple tasks at once.
Return value
The function returns:
Poll::Pending
if the unix stream is not ready for writing.Poll::Ready(Ok(()))
if the unix stream is ready for writing.Poll::Ready(Err(e))
if an error is encountered.
Errors
This function may encounter any standard I/O error except WouldBlock
.
sourcepub fn try_write(&self, buf: &[u8]) -> Result<usize>
pub fn try_write(&self, buf: &[u8]) -> Result<usize>
Tries to write a buffer to the stream, returning how many bytes were written.
The function will attempt to write the entire contents of buf
, but
only part of the buffer may be written.
This function is usually paired with writable()
.
Return
If data is successfully written, Ok(n)
is returned, where n
is the
number of bytes written. If the stream is not ready to write data,
Err(io::ErrorKind::WouldBlock)
is returned.
Examples
use tokio::net::UnixStream;
use std::error::Error;
use std::io;
#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
// Connect to a peer
let dir = tempfile::tempdir().unwrap();
let bind_path = dir.path().join("bind_path");
let stream = UnixStream::connect(bind_path).await?;
loop {
// Wait for the socket to be writable
stream.writable().await?;
// Try to write data, this may still fail with `WouldBlock`
// if the readiness event is a false positive.
match stream.try_write(b"hello world") {
Ok(n) => {
break;
}
Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
continue;
}
Err(e) => {
return Err(e.into());
}
}
}
Ok(())
}
sourcepub fn try_write_vectored(&self, buf: &[IoSlice<'_>]) -> Result<usize>
pub fn try_write_vectored(&self, buf: &[IoSlice<'_>]) -> Result<usize>
Tries to write several buffers to the stream, returning how many bytes were written.
Data is written from each buffer in order, with the final buffer read
from possible being only partially consumed. This method behaves
equivalently to a single call to try_write()
with concatenated
buffers.
This function is usually paired with writable()
.
Return
If data is successfully written, Ok(n)
is returned, where n
is the
number of bytes written. If the stream is not ready to write data,
Err(io::ErrorKind::WouldBlock)
is returned.
Examples
use tokio::net::UnixStream;
use std::error::Error;
use std::io;
#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
// Connect to a peer
let dir = tempfile::tempdir().unwrap();
let bind_path = dir.path().join("bind_path");
let stream = UnixStream::connect(bind_path).await?;
let bufs = [io::IoSlice::new(b"hello "), io::IoSlice::new(b"world")];
loop {
// Wait for the socket to be writable
stream.writable().await?;
// Try to write data, this may still fail with `WouldBlock`
// if the readiness event is a false positive.
match stream.try_write_vectored(&bufs) {
Ok(n) => {
break;
}
Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
continue;
}
Err(e) => {
return Err(e.into());
}
}
}
Ok(())
}
sourcepub fn try_io<R>(
&self,
interest: Interest,
f: impl FnOnce() -> Result<R>
) -> Result<R>
pub fn try_io<R>(
&self,
interest: Interest,
f: impl FnOnce() -> Result<R>
) -> Result<R>
Tries to read or write from the socket using a user-provided IO operation.
If the socket is ready, the provided closure is called. The closure
should attempt to perform IO operation from the socket by manually
calling the appropriate syscall. If the operation fails because the
socket is not actually ready, then the closure should return a
WouldBlock
error and the readiness flag is cleared. The return value
of the closure is then returned by try_io
.
If the socket is not ready, then the closure is not called
and a WouldBlock
error is returned.
The closure should only return a WouldBlock
error if it has performed
an IO operation on the socket that failed due to the socket not being
ready. Returning a WouldBlock
error in any other situation will
incorrectly clear the readiness flag, which can cause the socket to
behave incorrectly.
The closure should not perform the IO operation using any of the methods
defined on the Tokio UnixStream
type, as this will mess with the
readiness flag and can cause the socket to behave incorrectly.
Usually, readable()
, writable()
or ready()
is used with this function.
sourcepub fn from_std(stream: UnixStream) -> Result<UnixStream>
pub fn from_std(stream: UnixStream) -> Result<UnixStream>
Creates new UnixStream
from a std::os::unix::net::UnixStream
.
This function is intended to be used to wrap a UnixStream from the standard library in the Tokio equivalent. The conversion assumes nothing about the underlying stream; it is left up to the user to set it in non-blocking mode.
Panics
This function panics if thread-local runtime is not set.
The runtime is usually set implicitly when this function is called
from a future driven by a tokio runtime, otherwise runtime can be set
explicitly with Runtime::enter
function.
sourcepub fn into_std(self) -> Result<UnixStream>
pub fn into_std(self) -> Result<UnixStream>
Turns a tokio::net::UnixStream
into a std::os::unix::net::UnixStream
.
The returned std::os::unix::net::UnixStream
will have nonblocking
mode set as true
. Use set_nonblocking
to change the blocking
mode if needed.
Examples
use std::error::Error;
use std::io::Read;
use tokio::net::UnixListener;
#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
let dir = tempfile::tempdir().unwrap();
let bind_path = dir.path().join("bind_path");
let mut data = [0u8; 12];
let listener = UnixListener::bind(&bind_path)?;
let (tokio_unix_stream, _) = listener.accept().await?;
let mut std_unix_stream = tokio_unix_stream.into_std()?;
std_unix_stream.set_nonblocking(false)?;
std_unix_stream.read_exact(&mut data)?;
Ok(())
}
sourcepub fn pair() -> Result<(UnixStream, UnixStream)>
pub fn pair() -> Result<(UnixStream, UnixStream)>
Creates an unnamed pair of connected sockets.
This function will create a pair of interconnected Unix sockets for communicating back and forth between one another. Each socket will be associated with the default event loop’s handle.
sourcepub fn local_addr(&self) -> Result<SocketAddr>
pub fn local_addr(&self) -> Result<SocketAddr>
Returns the socket address of the local half of this connection.
Examples
use tokio::net::UnixStream;
let dir = tempfile::tempdir().unwrap();
let bind_path = dir.path().join("bind_path");
let stream = UnixStream::connect(bind_path).await?;
println!("{:?}", stream.local_addr()?);
sourcepub fn peer_addr(&self) -> Result<SocketAddr>
pub fn peer_addr(&self) -> Result<SocketAddr>
Returns the socket address of the remote half of this connection.
Examples
use tokio::net::UnixStream;
let dir = tempfile::tempdir().unwrap();
let bind_path = dir.path().join("bind_path");
let stream = UnixStream::connect(bind_path).await?;
println!("{:?}", stream.peer_addr()?);
sourcepub fn peer_cred(&self) -> Result<UCred>
pub fn peer_cred(&self) -> Result<UCred>
Returns effective credentials of the process which called connect
or pair
.
sourcepub fn take_error(&self) -> Result<Option<Error>>
pub fn take_error(&self) -> Result<Option<Error>>
Returns the value of the SO_ERROR
option.
sourcepub fn split<'a>(&'a mut self) -> (ReadHalf<'a>, WriteHalf<'a>)
pub fn split<'a>(&'a mut self) -> (ReadHalf<'a>, WriteHalf<'a>)
Splits a UnixStream
into a read half and a write half, which can be used
to read and write the stream concurrently.
This method is more efficient than into_split
, but the halves cannot be
moved into independently spawned tasks.
sourcepub fn into_split(self) -> (OwnedReadHalf, OwnedWriteHalf)
pub fn into_split(self) -> (OwnedReadHalf, OwnedWriteHalf)
Splits a UnixStream
into a read half and a write half, which can be used
to read and write the stream concurrently.
Unlike split
, the owned halves can be moved to separate tasks, however
this comes at the cost of a heap allocation.
Note: Dropping the write half will shut down the write half of the
stream. This is equivalent to calling shutdown()
on the UnixStream
.
Trait Implementations
sourceimpl AsRawFd for UnixStream
impl AsRawFd for UnixStream
sourceimpl AsRef<UnixStream> for ReadHalf<'_>
impl AsRef<UnixStream> for ReadHalf<'_>
sourcefn as_ref(&self) -> &UnixStream
fn as_ref(&self) -> &UnixStream
Converts this type into a shared reference of the (usually inferred) input type.
sourceimpl AsRef<UnixStream> for WriteHalf<'_>
impl AsRef<UnixStream> for WriteHalf<'_>
sourcefn as_ref(&self) -> &UnixStream
fn as_ref(&self) -> &UnixStream
Converts this type into a shared reference of the (usually inferred) input type.
sourceimpl AsRef<UnixStream> for OwnedReadHalf
impl AsRef<UnixStream> for OwnedReadHalf
sourcefn as_ref(&self) -> &UnixStream
fn as_ref(&self) -> &UnixStream
Converts this type into a shared reference of the (usually inferred) input type.
sourceimpl AsRef<UnixStream> for OwnedWriteHalf
impl AsRef<UnixStream> for OwnedWriteHalf
sourcefn as_ref(&self) -> &UnixStream
fn as_ref(&self) -> &UnixStream
Converts this type into a shared reference of the (usually inferred) input type.
sourceimpl AsyncRead for UnixStream
impl AsyncRead for UnixStream
sourceimpl AsyncWrite for UnixStream
impl AsyncWrite for UnixStream
sourcefn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8]
) -> Poll<Result<usize>>
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8]
) -> Poll<Result<usize>>
Attempt to write bytes from buf
into the object. Read more
sourcefn poll_write_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &[IoSlice<'_>]
) -> Poll<Result<usize>>
fn poll_write_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &[IoSlice<'_>]
) -> Poll<Result<usize>>
Like poll_write
, except that it writes from a slice of buffers. Read more
sourcefn is_write_vectored(&self) -> bool
fn is_write_vectored(&self) -> bool
Determines if this writer has an efficient poll_write_vectored
implementation. Read more
sourceimpl Debug for UnixStream
impl Debug for UnixStream
sourceimpl TryFrom<UnixStream> for UnixStream
impl TryFrom<UnixStream> for UnixStream
sourcefn try_from(stream: UnixStream) -> Result<Self>
fn try_from(stream: UnixStream) -> Result<Self>
Consumes stream, returning the tokio I/O object.
This is equivalent to
UnixStream::from_std(stream)
.
Auto Trait Implementations
impl RefUnwindSafe for UnixStream
impl Send for UnixStream
impl Sync for UnixStream
impl Unpin for UnixStream
impl UnwindSafe for UnixStream
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more