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Quelle named_pipe.rs
Sprache: unbekannt
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//! Tokio support for [Windows named pipes].
//!
//! [Windows named pipes]: https://docs.microsoft.com/en-us/windows/win32/ipc/named-pipes
use std::ffi::c_void;
use std::ffi::OsStr;
use std::io::{self, Read, Write};
use std::pin::Pin;
use std::ptr;
use std::task::{Context, Poll};
use crate::io::{AsyncRead, AsyncWrite, Interest, PollEvented, ReadBuf, Ready};
use crate::os::windows::io::{AsHandle, AsRawHandle, BorrowedHandle, FromRawHandle, Ra wHandle};
cfg_io_util! {
use bytes::BufMut;
}
// Hide imports which are not used when generating documentation.
#[cfg(not(docsrs))]
mod doc {
pub(super) use crate::os::windows::ffi::OsStrExt;
pub(super) mod windows_sys {
pub(crate) use windows_sys::{
Win32::Foundation::*, Win32::Storage::FileSystem::*, Win32::System::Pipes::*,
Win32::System::SystemServices::*,
};
}
pub(super) use mio::windows as mio_windows;
}
// NB: none of these shows up in public API, so don't document them.
#[cfg(docsrs)]
mod doc {
pub(super) mod mio_windows {
pub type NamedPipe = crate::doc::NotDefinedHere;
}
}
use self::doc::*;
/// A [Windows named pipe] server.
///
/// Accepting client connections involves creating a server with
/// [`ServerOptions::create`] and waiting for clients to connect using
/// [`NamedPipeServer::connect`].
///
/// To avoid having clients sporadically fail with
/// [`std::io::ErrorKind::NotFound`] when they connect to a server, we must
/// ensure that at least one server instance is available at all times. This
/// means that the typical listen loop for a server is a bit involved, because
/// we have to ensure that we never drop a server accidentally while a client
/// might connect.
///
/// So a correctly implemented server looks like this:
///
/// ```no_run
/// use std::io;
/// use tokio::net::windows::named_pipe::ServerOptions;
///
/// const PIPE_NAME: &str = r"\\.\pipe\named-pipe-idiomatic-server";
///
/// # #[tokio::main] async fn main() -> std::io::Result<()> {
/// // The first server needs to be constructed early so that clients can
/// // be correctly connected. Otherwise calling .wait will cause the client to
/// // error.
/// //
/// // Here we also make use of `first_pipe_instance`, which will ensure that
/// // there are no other servers up and running already.
/// let mut server = ServerOptions::new()
/// .first_pipe_instance(true)
/// .create(PIPE_NAME)?;
///
/// // Spawn the server loop.
/// let server = tokio::spawn(async move {
/// loop {
/// // Wait for a client to connect.
/// server.connect().await?;
/// let connected_client = server;
///
/// // Construct the next server to be connected before sending the one
/// // we already have of onto a task. This ensures that the server
/// // isn't closed (after it's done in the task) before a new one is
/// // available. Otherwise the client might error with
/// // `io::ErrorKind::NotFound`.
/// server = ServerOptions::new().create(PIPE_NAME)?;
///
/// let client = tokio::spawn(async move {
/// /* use the connected client */
/// # Ok::<_, std::io::Error>(())
/// });
/// # if true { break } // needed for type inference to work
/// }
///
/// Ok::<_, io::Error>(())
/// });
///
/// /* do something else not server related here */
/// # Ok(()) }
/// ```
///
/// [Windows named pipe]: https://docs.microsoft.com/en-us/windows/win32/ipc/named-pipes
#[derive(Debug)]
pub struct NamedPipeServer {
io: PollEvented<mio_windows::NamedPipe>,
}
impl NamedPipeServer {
/// Constructs a new named pipe server from the specified raw handle.
///
/// This function will consume ownership of the handle given, passing
/// responsibility for closing the handle to the returned object.
///
/// This function is also unsafe as the primitives currently returned have
/// the contract that they are the sole owner of the file descriptor they
/// are wrapping. Usage of this function could accidentally allow violating
/// this contract which can cause memory unsafety in code that relies on it
/// being true.
///
/// # Errors
///
/// This errors if called outside of a [Tokio Runtime], or in a runtime that
/// has not [enabled I/O], or if any OS-specific I/O errors occur.
///
/// [Tokio Runtime]: crate::runtime::Runtime
/// [enabled I/O]: crate::runtime::Builder::enable_io
pub unsafe fn from_raw_handle(handle: RawHandle) -> io::Result<Self> {
let named_pipe = mio_windows::NamedPipe::from_raw_handle(handle);
Ok(Self {
io: PollEvented::new(named_pipe)?,
})
}
/// Retrieves information about the named pipe the server is associated
/// with.
///
/// ```no_run
/// use tokio::net::windows::named_pipe::{PipeEnd, PipeMode, ServerOptions};
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-server-info";
///
/// # #[tokio::main] async fn main() -> std::io::Result<()> {
/// let server = ServerOptions::new()
/// .pipe_mode(PipeMode::Message)
/// .max_instances(5)
/// .create(PIPE_NAME)?;
///
/// let server_info = server.info()?;
///
/// assert_eq!(server_info.end, PipeEnd::Server);
/// assert_eq!(server_info.mode, PipeMode::Message);
/// assert_eq!(server_info.max_instances, 5);
/// # Ok(()) }
/// ```
pub fn info(&self) -> io::Result<PipeInfo> {
// Safety: we're ensuring the lifetime of the named pipe.
unsafe { named_pipe_info(self.io.as_raw_handle()) }
}
/// Enables a named pipe server process to wait for a client process to
/// connect to an instance of a named pipe. A client process connects by
/// creating a named pipe with the same name.
///
/// This corresponds to the [`ConnectNamedPipe`] system call.
///
/// # Cancel safety
///
/// This method is cancellation safe in the sense that if it is used as the
/// event in a [`select!`](crate::select) statement and some other branch
/// completes first, then no connection events have been lost.
///
/// [`ConnectNamedPipe`]: https://docs.microsoft.com/en-us/windows/win32/api/namedpipeapi/nf-namedpipeapi-connectnamedpipe
///
/// # Example
///
/// ```no_run
/// use tokio::net::windows::named_pipe::ServerOptions;
///
/// const PIPE_NAME: &str = r"\\.\pipe\mynamedpipe";
///
/// # #[tokio::main] async fn main() -> std::io::Result<()> {
/// let pipe = ServerOptions::new().create(PIPE_NAME)?;
///
/// // Wait for a client to connect.
/// pipe.connect().await?;
///
/// // Use the connected client...
/// # Ok(()) }
/// ```
pub async fn connect(&self) -> io::Result<()> {
match self.io.connect() {
Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
self.io
.registration()
.async_io(Interest::WRITABLE, || self.io.connect())
.await
}
x => x,
}
}
/// Disconnects the server end of a named pipe instance from a client
/// process.
///
/// ```
/// use tokio::io::AsyncWriteExt;
/// use tokio::net::windows::named_pipe::{ClientOptions, ServerOptions};
/// use windows_sys::Win32::Foundation::ERROR_PIPE_NOT_CONNECTED;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-disconnect";
///
/// # #[tokio::main] async fn main() -> std::io::Result<()> {
/// let server = ServerOptions::new()
/// .create(PIPE_NAME)?;
///
/// let mut client = ClientOptions::new()
/// .open(PIPE_NAME)?;
///
/// // Wait for a client to become connected.
/// server.connect().await?;
///
/// // Forcibly disconnect the client.
/// server.disconnect()?;
///
/// // Write fails with an OS-specific error after client has been
/// // disconnected.
/// let e = client.write(b"ping").await.unwrap_err();
/// assert_eq!(e.raw_os_error(), Some(ERROR_PIPE_NOT_CONNECTED as i32));
/// # Ok(()) }
/// ```
pub fn disconnect(&self) -> io::Result<()> {
self.io.disconnect()
}
/// 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 pipe on a single
/// task without splitting the pipe.
///
/// The function may complete without the pipe being ready. This is a
/// false-positive and attempting an operation will return with
/// `io::ErrorKind::WouldBlock`. The function can also return with an empty
/// [`Ready`] set, so you should always check the returned value and possibly
/// wait again if the requested states are not set.
///
/// # Examples
///
/// Concurrently read and write to the pipe on the same task without
/// splitting.
///
/// ```no_run
/// use tokio::io::Interest;
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-server-ready";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let server = named_pipe::ServerOptions::new()
/// .create(PIPE_NAME)?;
///
/// loop {
/// let ready = server.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 server.try_read(&mut data) {
/// Ok(n) => {
/// println!("read {} bytes", n);
/// }
/// Err(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 server.try_write(b"hello world") {
/// Ok(n) => {
/// println!("write {} bytes", n);
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
/// }
/// }
/// ```
pub async fn ready(&self, interest: Interest) -> io::Result<Ready> {
let event = self.io.registration().readiness(interest).await?;
Ok(event.ready)
}
/// Waits for the pipe to become readable.
///
/// This function is equivalent to `ready(Interest::READABLE)` and is usually
/// paired with `try_read()`.
///
/// # Examples
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-server-readable";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let server = named_pipe::ServerOptions::new()
/// .create(PIPE_NAME)?;
///
/// let mut msg = vec![0; 1024];
///
/// loop {
/// // Wait for the pipe to be readable
/// server.readable().await?;
///
/// // Try to read data, this may still fail with `WouldBlock`
/// // if the readiness event is a false positive.
/// match server.try_read(&mut msg) {
/// Ok(n) => {
/// msg.truncate(n);
/// break;
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
///
/// println!("GOT = {:?}", msg);
/// Ok(())
/// }
/// ```
pub async fn readable(&self) -> io::Result<()> {
self.ready(Interest::READABLE).await?;
Ok(())
}
/// Polls for read readiness.
///
/// If the pipe is not currently ready for reading, this method will
/// store a clone of the `Waker` from the provided `Context`. When the pipe
/// 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 pipe is not ready for reading.
/// * `Poll::Ready(Ok(()))` if the pipe 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`.
///
/// [`readable`]: method@Self::readable
pub fn poll_read_ready(&self, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
self.io.registration().poll_read_ready(cx).map_ok(|_| ())
}
/// Tries to read data from the pipe into the provided buffer, returning how
/// many bytes were read.
///
/// Receives any pending data from the pipe 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.
///
/// [`readable()`]: NamedPipeServer::readable()
/// [`ready()`]: NamedPipeServer::ready()
///
/// # Return
///
/// If data is successfully read, `Ok(n)` is returned, where `n` is the
/// number of bytes read. If `n` is `0`, then it can indicate one of two scenarios:
///
/// 1. The pipe's read half is closed and will no longer yield data.
/// 2. The specified buffer was 0 bytes in length.
///
/// If the pipe is not ready to read data,
/// `Err(io::ErrorKind::WouldBlock)` is returned.
///
/// # Examples
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-server-try-read";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let server = named_pipe::ServerOptions::new()
/// .create(PIPE_NAME)?;
///
/// loop {
/// // Wait for the pipe to be readable
/// server.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 server.try_read(&mut buf) {
/// Ok(0) => break,
/// Ok(n) => {
/// println!("read {} bytes", n);
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
///
/// Ok(())
/// }
/// ```
pub fn try_read(&self, buf: &mut [u8]) -> io::Result<usize> {
self.io
.registration()
.try_io(Interest::READABLE, || (&*self.io).read(buf))
}
/// Tries to read data from the pipe 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 pipe 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.
///
/// [`try_read()`]: NamedPipeServer::try_read()
/// [`readable()`]: NamedPipeServer::readable()
/// [`ready()`]: NamedPipeServer::ready()
///
/// # Return
///
/// If data is successfully read, `Ok(n)` is returned, where `n` is the
/// number of bytes read. `Ok(0)` indicates the pipe's read half is closed
/// and will no longer yield data. If the pipe is not ready to read data
/// `Err(io::ErrorKind::WouldBlock)` is returned.
///
/// # Examples
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io::{self, IoSliceMut};
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-server-try-read-vectored";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let server = named_pipe::ServerOptions::new()
/// .create(PIPE_NAME)?;
///
/// loop {
/// // Wait for the pipe to be readable
/// server.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 server.try_read_vectored(&mut bufs) {
/// Ok(0) => break,
/// Ok(n) => {
/// println!("read {} bytes", n);
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
///
/// Ok(())
/// }
/// ```
pub fn try_read_vectored(&self, bufs: &mut [io::IoSliceMut<'_>]) -> io::Result<usize> {
self.io
.registration()
.try_io(Interest::READABLE, || (&*self.io).read_vectored(bufs))
}
cfg_io_util! {
/// 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 pipe 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.
///
/// [`readable()`]: NamedPipeServer::readable()
/// [`ready()`]: NamedPipeServer::ready()
///
/// # 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
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-client-readable";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let server = named_pipe::ServerOptions::new().create(PIPE_NAME)?;
///
/// loop {
/// // Wait for the pipe to be readable
/// server.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 server.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(())
/// }
/// ```
pub fn try_read_buf<B: BufMut>(&self, buf: &mut B) -> io::Result<usize> {
self.io.registration().try_io(Interest::READABLE, || {
use std::io::Read;
let dst = buf.chunk_mut();
let dst =
unsafe { &mut *(dst as *mut _ as *mut [std::mem::MaybeUninit<u8>] as *mut [u8]) };
// Safety: We trust `NamedPipeServer::read` to have filled up `n` bytes in the
// buffer.
let n = (&*self.io).read(dst)?;
unsafe {
buf.advance_mut(n);
}
Ok(n)
})
}
}
/// Waits for the pipe to become writable.
///
/// This function is equivalent to `ready(Interest::WRITABLE)` and is usually
/// paired with `try_write()`.
///
/// # Examples
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-server-writable";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let server = named_pipe::ServerOptions::new()
/// .create(PIPE_NAME)?;
///
/// loop {
/// // Wait for the pipe to be writable
/// server.writable().await?;
///
/// // Try to write data, this may still fail with `WouldBlock`
/// // if the readiness event is a false positive.
/// match server.try_write(b"hello world") {
/// Ok(n) => {
/// break;
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
///
/// Ok(())
/// }
/// ```
pub async fn writable(&self) -> io::Result<()> {
self.ready(Interest::WRITABLE).await?;
Ok(())
}
/// Polls for write readiness.
///
/// If the pipe is not currently ready for writing, this method will
/// store a clone of the `Waker` from the provided `Context`. When the pipe
/// 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 pipe is not ready for writing.
/// * `Poll::Ready(Ok(()))` if the pipe 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`.
///
/// [`writable`]: method@Self::writable
pub fn poll_write_ready(&self, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
self.io.registration().poll_write_ready(cx).map_ok(|_| ())
}
/// Tries to write a buffer to the pipe, 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 pipe is not ready to write data,
/// `Err(io::ErrorKind::WouldBlock)` is returned.
///
/// # Examples
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-server-try-write";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let server = named_pipe::ServerOptions::new()
/// .create(PIPE_NAME)?;
///
/// loop {
/// // Wait for the pipe to be writable
/// server.writable().await?;
///
/// // Try to write data, this may still fail with `WouldBlock`
/// // if the readiness event is a false positive.
/// match server.try_write(b"hello world") {
/// Ok(n) => {
/// break;
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
///
/// Ok(())
/// }
/// ```
pub fn try_write(&self, buf: &[u8]) -> io::Result<usize> {
self.io
.registration()
.try_io(Interest::WRITABLE, || (&*self.io).write(buf))
}
/// Tries to write several buffers to the pipe, 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()`.
///
/// [`try_write()`]: NamedPipeServer::try_write()
///
/// # Return
///
/// If data is successfully written, `Ok(n)` is returned, where `n` is the
/// number of bytes written. If the pipe is not ready to write data,
/// `Err(io::ErrorKind::WouldBlock)` is returned.
///
/// # Examples
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-server-try-write-vectored";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let server = named_pipe::ServerOptions::new()
/// .create(PIPE_NAME)?;
///
/// let bufs = [io::IoSlice::new(b"hello "), io::IoSlice::new(b"world")];
///
/// loop {
/// // Wait for the pipe to be writable
/// server.writable().await?;
///
/// // Try to write data, this may still fail with `WouldBlock`
/// // if the readiness event is a false positive.
/// match server.try_write_vectored(&bufs) {
/// Ok(n) => {
/// break;
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
///
/// Ok(())
/// }
/// ```
pub fn try_write_vectored(&self, buf: &[io::IoSlice<'_>]) -> io::Result<usize> {
self.io
.registration()
.try_io(Interest::WRITABLE, || (&*self.io).write_vectored(buf))
}
/// Tries to read or write from the pipe using a user-provided IO operation.
///
/// If the pipe is ready, the provided closure is called. The closure
/// should attempt to perform IO operation from the pipe by manually
/// calling the appropriate syscall. If the operation fails because the
/// pipe 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 pipe 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 pipe that failed due to the pipe not being
/// ready. Returning a `WouldBlock` error in any other situation will
/// incorrectly clear the readiness flag, which can cause the pipe to
/// behave incorrectly.
///
/// The closure should not perform the IO operation using any of the
/// methods defined on the Tokio `NamedPipeServer` type, as this will mess with
/// the readiness flag and can cause the pipe to behave incorrectly.
///
/// This method is not intended to be used with combined interests.
/// The closure should perform only one type of IO operation, so it should not
/// require more than one ready state. This method may panic or sleep forever
/// if it is called with a combined interest.
///
/// Usually, [`readable()`], [`writable()`] or [`ready()`] is used with this function.
///
/// [`readable()`]: NamedPipeServer::readable()
/// [`writable()`]: NamedPipeServer::writable()
/// [`ready()`]: NamedPipeServer::ready()
pub fn try_io<R>(
&self,
interest: Interest,
f: impl FnOnce() -> io::Result<R>,
) -> io::Result<R> {
self.io.registration().try_io(interest, f)
}
/// Reads or writes from the pipe using a user-provided IO operation.
///
/// The readiness of the pipe is awaited and when the pipe is ready,
/// the provided closure is called. The closure should attempt to perform
/// IO operation on the pipe by manually calling the appropriate syscall.
/// If the operation fails because the pipe is not actually ready,
/// then the closure should return a `WouldBlock` error. In such case the
/// readiness flag is cleared and the pipe readiness is awaited again.
/// This loop is repeated until the closure returns an `Ok` or an error
/// other than `WouldBlock`.
///
/// The closure should only return a `WouldBlock` error if it has performed
/// an IO operation on the pipe that failed due to the pipe not being
/// ready. Returning a `WouldBlock` error in any other situation will
/// incorrectly clear the readiness flag, which can cause the pipe to
/// behave incorrectly.
///
/// The closure should not perform the IO operation using any of the methods
/// defined on the Tokio `NamedPipeServer` type, as this will mess with the
/// readiness flag and can cause the pipe to behave incorrectly.
///
/// This method is not intended to be used with combined interests.
/// The closure should perform only one type of IO operation, so it should not
/// require more than one ready state. This method may panic or sleep forever
/// if it is called with a combined interest.
pub async fn async_io<R>(
&self,
interest: Interest,
f: impl FnMut() -> io::Result<R>,
) -> io::Result<R> {
self.io.registration().async_io(interest, f).await
}
}
impl AsyncRead for NamedPipeServer {
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut ReadBuf<'_>,
) -> Poll<io::Result<()>> {
unsafe { self.io.poll_read(cx, buf) }
}
}
impl AsyncWrite for NamedPipeServer {
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<io::Result<usize>> {
self.io.poll_write(cx, buf)
}
fn poll_write_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &[io::IoSlice<'_>],
) -> Poll<io::Result<usize>> {
self.io.poll_write_vectored(cx, bufs)
}
fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
Poll::Ready(Ok(()))
}
fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
self.poll_flush(cx)
}
}
impl AsRawHandle for NamedPipeServer {
fn as_raw_handle(&self) -> RawHandle {
self.io.as_raw_handle()
}
}
impl AsHandle for NamedPipeServer {
fn as_handle(&self) -> BorrowedHandle<'_> {
unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
}
}
/// A [Windows named pipe] client.
///
/// Constructed using [`ClientOptions::open`].
///
/// Connecting a client correctly involves a few steps. When connecting through
/// [`ClientOptions::open`], it might error indicating one of two things:
///
/// * [`std::io::ErrorKind::NotFound`] - There is no server available.
/// * [`ERROR_PIPE_BUSY`] - There is a server available, but it is busy. Sleep
/// for a while and try again.
///
/// So a correctly implemented client looks like this:
///
/// ```no_run
/// use std::time::Duration;
/// use tokio::net::windows::named_pipe::ClientOptions;
/// use tokio::time;
/// use windows_sys::Win32::Foundation::ERROR_PIPE_BUSY;
///
/// const PIPE_NAME: &str = r"\\.\pipe\named-pipe-idiomatic-client";
///
/// # #[tokio::main] async fn main() -> std::io::Result<()> {
/// let client = loop {
/// match ClientOptions::new().open(PIPE_NAME) {
/// Ok(client) => break client,
/// Err(e) if e.raw_os_error() == Some(ERROR_PIPE_BUSY as i32) => (),
/// Err(e) => return Err(e),
/// }
///
/// time::sleep(Duration::from_millis(50)).await;
/// };
///
/// /* use the connected client */
/// # Ok(()) }
/// ```
///
/// [`ERROR_PIPE_BUSY`]: https://docs.rs/windows-sys/latest/windows_sys/Win32/Foundation/constant.ERROR_PIPE_BUSY.html
/// [Windows named pipe]: https://docs.microsoft.com/en-us/windows/win32/ipc/named-pipes
#[derive(Debug)]
pub struct NamedPipeClient {
io: PollEvented<mio_windows::NamedPipe>,
}
impl NamedPipeClient {
/// Constructs a new named pipe client from the specified raw handle.
///
/// This function will consume ownership of the handle given, passing
/// responsibility for closing the handle to the returned object.
///
/// This function is also unsafe as the primitives currently returned have
/// the contract that they are the sole owner of the file descriptor they
/// are wrapping. Usage of this function could accidentally allow violating
/// this contract which can cause memory unsafety in code that relies on it
/// being true.
///
/// # Errors
///
/// This errors if called outside of a [Tokio Runtime], or in a runtime that
/// has not [enabled I/O], or if any OS-specific I/O errors occur.
///
/// [Tokio Runtime]: crate::runtime::Runtime
/// [enabled I/O]: crate::runtime::Builder::enable_io
pub unsafe fn from_raw_handle(handle: RawHandle) -> io::Result<Self> {
let named_pipe = mio_windows::NamedPipe::from_raw_handle(handle);
Ok(Self {
io: PollEvented::new(named_pipe)?,
})
}
/// Retrieves information about the named pipe the client is associated
/// with.
///
/// ```no_run
/// use tokio::net::windows::named_pipe::{ClientOptions, PipeEnd, PipeMode};
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-client-info";
///
/// # #[tokio::main] async fn main() -> std::io::Result<()> {
/// let client = ClientOptions::new()
/// .open(PIPE_NAME)?;
///
/// let client_info = client.info()?;
///
/// assert_eq!(client_info.end, PipeEnd::Client);
/// assert_eq!(client_info.mode, PipeMode::Message);
/// assert_eq!(client_info.max_instances, 5);
/// # Ok(()) }
/// ```
pub fn info(&self) -> io::Result<PipeInfo> {
// Safety: we're ensuring the lifetime of the named pipe.
unsafe { named_pipe_info(self.io.as_raw_handle()) }
}
/// 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 pipe on a single
/// task without splitting the pipe.
///
/// The function may complete without the pipe being ready. This is a
/// false-positive and attempting an operation will return with
/// `io::ErrorKind::WouldBlock`. The function can also return with an empty
/// [`Ready`] set, so you should always check the returned value and possibly
/// wait again if the requested states are not set.
///
/// # Examples
///
/// Concurrently read and write to the pipe on the same task without
/// splitting.
///
/// ```no_run
/// use tokio::io::Interest;
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-client-ready";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let client = named_pipe::ClientOptions::new().open(PIPE_NAME)?;
///
/// loop {
/// let ready = client.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 client.try_read(&mut data) {
/// Ok(n) => {
/// println!("read {} bytes", n);
/// }
/// Err(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 client.try_write(b"hello world") {
/// Ok(n) => {
/// println!("write {} bytes", n);
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
/// }
/// }
/// ```
pub async fn ready(&self, interest: Interest) -> io::Result<Ready> {
let event = self.io.registration().readiness(interest).await?;
Ok(event.ready)
}
/// Waits for the pipe to become readable.
///
/// This function is equivalent to `ready(Interest::READABLE)` and is usually
/// paired with `try_read()`.
///
/// # Examples
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-client-readable";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let client = named_pipe::ClientOptions::new().open(PIPE_NAME)?;
///
/// let mut msg = vec![0; 1024];
///
/// loop {
/// // Wait for the pipe to be readable
/// client.readable().await?;
///
/// // Try to read data, this may still fail with `WouldBlock`
/// // if the readiness event is a false positive.
/// match client.try_read(&mut msg) {
/// Ok(n) => {
/// msg.truncate(n);
/// break;
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
///
/// println!("GOT = {:?}", msg);
/// Ok(())
/// }
/// ```
pub async fn readable(&self) -> io::Result<()> {
self.ready(Interest::READABLE).await?;
Ok(())
}
/// Polls for read readiness.
///
/// If the pipe is not currently ready for reading, this method will
/// store a clone of the `Waker` from the provided `Context`. When the pipe
/// 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 pipe is not ready for reading.
/// * `Poll::Ready(Ok(()))` if the pipe 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`.
///
/// [`readable`]: method@Self::readable
pub fn poll_read_ready(&self, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
self.io.registration().poll_read_ready(cx).map_ok(|_| ())
}
/// Tries to read data from the pipe into the provided buffer, returning how
/// many bytes were read.
///
/// Receives any pending data from the pipe 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.
///
/// [`readable()`]: NamedPipeClient::readable()
/// [`ready()`]: NamedPipeClient::ready()
///
/// # Return
///
/// If data is successfully read, `Ok(n)` is returned, where `n` is the
/// number of bytes read. If `n` is `0`, then it can indicate one of two scenarios:
///
/// 1. The pipe's read half is closed and will no longer yield data.
/// 2. The specified buffer was 0 bytes in length.
///
/// If the pipe is not ready to read data,
/// `Err(io::ErrorKind::WouldBlock)` is returned.
///
/// # Examples
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-client-try-read";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let client = named_pipe::ClientOptions::new().open(PIPE_NAME)?;
///
/// loop {
/// // Wait for the pipe to be readable
/// client.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 client.try_read(&mut buf) {
/// Ok(0) => break,
/// Ok(n) => {
/// println!("read {} bytes", n);
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
///
/// Ok(())
/// }
/// ```
pub fn try_read(&self, buf: &mut [u8]) -> io::Result<usize> {
self.io
.registration()
.try_io(Interest::READABLE, || (&*self.io).read(buf))
}
/// Tries to read data from the pipe 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 pipe 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.
///
/// [`try_read()`]: NamedPipeClient::try_read()
/// [`readable()`]: NamedPipeClient::readable()
/// [`ready()`]: NamedPipeClient::ready()
///
/// # Return
///
/// If data is successfully read, `Ok(n)` is returned, where `n` is the
/// number of bytes read. `Ok(0)` indicates the pipe's read half is closed
/// and will no longer yield data. If the pipe is not ready to read data
/// `Err(io::ErrorKind::WouldBlock)` is returned.
///
/// # Examples
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io::{self, IoSliceMut};
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-client-try-read-vectored";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let client = named_pipe::ClientOptions::new().open(PIPE_NAME)?;
///
/// loop {
/// // Wait for the pipe to be readable
/// client.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 client.try_read_vectored(&mut bufs) {
/// Ok(0) => break,
/// Ok(n) => {
/// println!("read {} bytes", n);
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
///
/// Ok(())
/// }
/// ```
pub fn try_read_vectored(&self, bufs: &mut [io::IoSliceMut<'_>]) -> io::Result<usize> {
self.io
.registration()
.try_io(Interest::READABLE, || (&*self.io).read_vectored(bufs))
}
cfg_io_util! {
/// 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 pipe 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.
///
/// [`readable()`]: NamedPipeClient::readable()
/// [`ready()`]: NamedPipeClient::ready()
///
/// # 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
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-client-readable";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let client = named_pipe::ClientOptions::new().open(PIPE_NAME)?;
///
/// loop {
/// // Wait for the pipe to be readable
/// client.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 client.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(())
/// }
/// ```
pub fn try_read_buf<B: BufMut>(&self, buf: &mut B) -> io::Result<usize> {
self.io.registration().try_io(Interest::READABLE, || {
use std::io::Read;
let dst = buf.chunk_mut();
let dst =
unsafe { &mut *(dst as *mut _ as *mut [std::mem::MaybeUninit<u8>] as *mut [u8]) };
// Safety: We trust `NamedPipeClient::read` to have filled up `n` bytes in the
// buffer.
let n = (&*self.io).read(dst)?;
unsafe {
buf.advance_mut(n);
}
Ok(n)
})
}
}
/// Waits for the pipe to become writable.
///
/// This function is equivalent to `ready(Interest::WRITABLE)` and is usually
/// paired with `try_write()`.
///
/// # Examples
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-client-writable";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let client = named_pipe::ClientOptions::new().open(PIPE_NAME)?;
///
/// loop {
/// // Wait for the pipe to be writable
/// client.writable().await?;
///
/// // Try to write data, this may still fail with `WouldBlock`
/// // if the readiness event is a false positive.
/// match client.try_write(b"hello world") {
/// Ok(n) => {
/// break;
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
///
/// Ok(())
/// }
/// ```
pub async fn writable(&self) -> io::Result<()> {
self.ready(Interest::WRITABLE).await?;
Ok(())
}
/// Polls for write readiness.
///
/// If the pipe is not currently ready for writing, this method will
/// store a clone of the `Waker` from the provided `Context`. When the pipe
/// 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 pipe is not ready for writing.
/// * `Poll::Ready(Ok(()))` if the pipe 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`.
///
/// [`writable`]: method@Self::writable
pub fn poll_write_ready(&self, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
self.io.registration().poll_write_ready(cx).map_ok(|_| ())
}
/// Tries to write a buffer to the pipe, 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 pipe is not ready to write data,
/// `Err(io::ErrorKind::WouldBlock)` is returned.
///
/// # Examples
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-client-try-write";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let client = named_pipe::ClientOptions::new().open(PIPE_NAME)?;
///
/// loop {
/// // Wait for the pipe to be writable
/// client.writable().await?;
///
/// // Try to write data, this may still fail with `WouldBlock`
/// // if the readiness event is a false positive.
/// match client.try_write(b"hello world") {
/// Ok(n) => {
/// break;
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
///
/// Ok(())
/// }
/// ```
pub fn try_write(&self, buf: &[u8]) -> io::Result<usize> {
self.io
.registration()
.try_io(Interest::WRITABLE, || (&*self.io).write(buf))
}
/// Tries to write several buffers to the pipe, 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()`.
///
/// [`try_write()`]: NamedPipeClient::try_write()
///
/// # Return
///
/// If data is successfully written, `Ok(n)` is returned, where `n` is the
/// number of bytes written. If the pipe is not ready to write data,
/// `Err(io::ErrorKind::WouldBlock)` is returned.
///
/// # Examples
///
/// ```no_run
/// use tokio::net::windows::named_pipe;
/// use std::error::Error;
/// use std::io;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-client-try-write-vectored";
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn Error>> {
/// let client = named_pipe::ClientOptions::new().open(PIPE_NAME)?;
///
/// let bufs = [io::IoSlice::new(b"hello "), io::IoSlice::new(b"world")];
///
/// loop {
/// // Wait for the pipe to be writable
/// client.writable().await?;
///
/// // Try to write data, this may still fail with `WouldBlock`
/// // if the readiness event is a false positive.
/// match client.try_write_vectored(&bufs) {
/// Ok(n) => {
/// break;
/// }
/// Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
/// continue;
/// }
/// Err(e) => {
/// return Err(e.into());
/// }
/// }
/// }
///
/// Ok(())
/// }
/// ```
pub fn try_write_vectored(&self, buf: &[io::IoSlice<'_>]) -> io::Result<usize> {
self.io
.registration()
.try_io(Interest::WRITABLE, || (&*self.io).write_vectored(buf))
}
/// Tries to read or write from the pipe using a user-provided IO operation.
///
/// If the pipe is ready, the provided closure is called. The closure
/// should attempt to perform IO operation from the pipe by manually
/// calling the appropriate syscall. If the operation fails because the
/// pipe 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 pipe 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 pipe that failed due to the pipe not being
/// ready. Returning a `WouldBlock` error in any other situation will
/// incorrectly clear the readiness flag, which can cause the pipe to
/// behave incorrectly.
///
/// The closure should not perform the IO operation using any of the methods
/// defined on the Tokio `NamedPipeClient` type, as this will mess with the
/// readiness flag and can cause the pipe to behave incorrectly.
///
/// This method is not intended to be used with combined interests.
/// The closure should perform only one type of IO operation, so it should not
/// require more than one ready state. This method may panic or sleep forever
/// if it is called with a combined interest.
///
/// Usually, [`readable()`], [`writable()`] or [`ready()`] is used with this function.
///
/// [`readable()`]: NamedPipeClient::readable()
/// [`writable()`]: NamedPipeClient::writable()
/// [`ready()`]: NamedPipeClient::ready()
pub fn try_io<R>(
&self,
interest: Interest,
f: impl FnOnce() -> io::Result<R>,
) -> io::Result<R> {
self.io.registration().try_io(interest, f)
}
/// Reads or writes from the pipe using a user-provided IO operation.
///
/// The readiness of the pipe is awaited and when the pipe is ready,
/// the provided closure is called. The closure should attempt to perform
/// IO operation on the pipe by manually calling the appropriate syscall.
/// If the operation fails because the pipe is not actually ready,
/// then the closure should return a `WouldBlock` error. In such case the
/// readiness flag is cleared and the pipe readiness is awaited again.
/// This loop is repeated until the closure returns an `Ok` or an error
/// other than `WouldBlock`.
///
/// The closure should only return a `WouldBlock` error if it has performed
/// an IO operation on the pipe that failed due to the pipe not being
/// ready. Returning a `WouldBlock` error in any other situation will
/// incorrectly clear the readiness flag, which can cause the pipe to
/// behave incorrectly.
///
/// The closure should not perform the IO operation using any of the methods
/// defined on the Tokio `NamedPipeClient` type, as this will mess with the
/// readiness flag and can cause the pipe to behave incorrectly.
///
/// This method is not intended to be used with combined interests.
/// The closure should perform only one type of IO operation, so it should not
/// require more than one ready state. This method may panic or sleep forever
/// if it is called with a combined interest.
pub async fn async_io<R>(
&self,
interest: Interest,
f: impl FnMut() -> io::Result<R>,
) -> io::Result<R> {
self.io.registration().async_io(interest, f).await
}
}
impl AsyncRead for NamedPipeClient {
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut ReadBuf<'_>,
) -> Poll<io::Result<()>> {
unsafe { self.io.poll_read(cx, buf) }
}
}
impl AsyncWrite for NamedPipeClient {
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<io::Result<usize>> {
self.io.poll_write(cx, buf)
}
fn poll_write_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &[io::IoSlice<'_>],
) -> Poll<io::Result<usize>> {
self.io.poll_write_vectored(cx, bufs)
}
fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
Poll::Ready(Ok(()))
}
fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
self.poll_flush(cx)
}
}
impl AsRawHandle for NamedPipeClient {
fn as_raw_handle(&self) -> RawHandle {
self.io.as_raw_handle()
}
}
impl AsHandle for NamedPipeClient {
fn as_handle(&self) -> BorrowedHandle<'_> {
unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
}
}
/// A builder structure for construct a named pipe with named pipe-specific
/// options. This is required to use for named pipe servers who wants to modify
/// pipe-related options.
///
/// See [`ServerOptions::create`].
#[derive(Debug, Clone)]
pub struct ServerOptions {
// dwOpenMode
access_inbound: bool,
access_outbound: bool,
first_pipe_instance: bool,
write_dac: bool,
write_owner: bool,
access_system_security: bool,
// dwPipeMode
pipe_mode: PipeMode,
reject_remote_clients: bool,
// other options
max_instances: u32,
out_buffer_size: u32,
in_buffer_size: u32,
default_timeout: u32,
}
impl ServerOptions {
/// Creates a new named pipe builder with the default settings.
///
/// ```
/// use tokio::net::windows::named_pipe::ServerOptions;
///
/// const PIPE_NAME: &str = r"\\.\pipe\tokio-named-pipe-new";
///
/// # #[tokio::main] async fn main() -> std::io::Result<()> {
/// let server = ServerOptions::new().create(PIPE_NAME)?;
/// # Ok(()) }
/// ```
pub fn new() -> ServerOptions {
ServerOptions {
access_inbound: true,
access_outbound: true,
first_pipe_instance: false,
write_dac: false,
write_owner: false,
access_system_security: false,
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[ Dauer der Verarbeitung: 0.38 Sekunden
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