[][src]Struct tokio_reactor::PollEvented

pub struct PollEvented<E: Evented> { /* fields omitted */ }

Associates an I/O resource that implements the std::io::Read and/or std::io::Write traits with the reactor that drives it.

PollEvented uses Registration internally to take a type that implements mio::Evented as well as std::io::Read and or std::io::Write and associate it with a reactor that will drive it.

Once the mio::Evented type is wrapped by PollEvented, it can be used from within the future's execution model. As such, the PollEvented type provides AsyncRead and AsyncWrite implementations using the underlying I/O resource as well as readiness events provided by the reactor.

Note: While PollEvented is Sync (if the underlying I/O type is Sync), the caller must ensure that there are at most two tasks that use a PollEvented instance concurrently. One for reading and one for writing. While violating this requirement is "safe" from a Rust memory model point of view, it will result in unexpected behavior in the form of lost notifications and tasks hanging.

Readiness events

Besides just providing AsyncRead and AsyncWrite implementations, this type also supports access to the underlying readiness event stream. While similar in function to what Registration provides, the semantics are a bit different.

Two functions are provided to access the readiness events: poll_read_ready and poll_write_ready. These functions return the current readiness state of the PollEvented instance. If poll_read_ready indicates read readiness, immediately calling poll_read_ready again will also indicate read readiness.

When the operation is attempted and is unable to succeed due to the I/O resource not being ready, the caller must call clear_read_ready or clear_write_ready. This clears the readiness state until a new readiness event is received.

This allows the caller to implement additional functions. For example, TcpListener implements poll_accept by using poll_read_ready and clear_read_ready.

This example is not tested
pub fn poll_accept(&mut self) -> Poll<(net::TcpStream, SocketAddr), io::Error> {
    let ready = Ready::readable();

    try_ready!(self.poll_evented.poll_read_ready(ready));

    match self.poll_evented.get_ref().accept_std() {
        Ok(pair) => Ok(Async::Ready(pair)),
        Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
            self.poll_evented.clear_read_ready(ready);
            Ok(Async::NotReady)
        }
        Err(e) => Err(e),
    }
}

Platform-specific events

PollEvented also allows receiving platform-specific mio::Ready events. These events are included as part of the read readiness event stream. The write readiness event stream is only for Ready::writable() events.

Methods

impl<E> PollEvented<E> where
    E: Evented
[src]

Important traits for PollEvented<E>
pub fn new(io: E) -> PollEvented<E>[src]

Creates a new PollEvented associated with the default reactor.

pub fn new_with_handle(io: E, handle: &Handle) -> Result<Self>[src]

Creates a new PollEvented associated with the specified reactor.

pub fn get_ref(&self) -> &E[src]

Returns a shared reference to the underlying I/O object this readiness stream is wrapping.

pub fn get_mut(&mut self) -> &mut E[src]

Returns a mutable reference to the underlying I/O object this readiness stream is wrapping.

pub fn into_inner(self) -> Result<E>[src]

Consumes self, returning the inner I/O object

This function will deregister the I/O resource from the reactor before returning. If the deregistration operation fails, an error is returned.

Note that deregistering does not guarantee that the I/O resource can be registered with a different reactor. Some I/O resource types can only be associated with a single reactor instance for their lifetime.

pub fn poll_read_ready(&self, mask: Ready) -> Poll<Ready, Error>[src]

Check the I/O resource's read readiness state.

The mask argument allows specifying what readiness to notify on. This can be any value, including platform specific readiness, except writable. HUP is always implicitly included on platforms that support it.

If the resource is not ready for a read then Async::NotReady is returned and the current task is notified once a new event is received.

The I/O resource will remain in a read-ready state until readiness is cleared by calling clear_read_ready.

Panics

This function panics if:

  • ready includes writable.
  • called from outside of a task context.

pub fn clear_read_ready(&self, ready: Ready) -> Result<()>[src]

Clears the I/O resource's read readiness state and registers the current task to be notified once a read readiness event is received.

After calling this function, poll_read_ready will return NotReady until a new read readiness event has been received.

The mask argument specifies the readiness bits to clear. This may not include writable or hup.

Panics

This function panics if:

  • ready includes writable or HUP
  • called from outside of a task context.

pub fn poll_write_ready(&self) -> Poll<Ready, Error>[src]

Check the I/O resource's write readiness state.

This always checks for writable readiness and also checks for HUP readiness on platforms that support it.

If the resource is not ready for a write then Async::NotReady is returned and the current task is notified once a new event is received.

The I/O resource will remain in a write-ready state until readiness is cleared by calling clear_write_ready.

Panics

This function panics if:

  • ready contains bits besides writable and hup.
  • called from outside of a task context.

pub fn clear_write_ready(&self) -> Result<()>[src]

Resets the I/O resource's write readiness state and registers the current task to be notified once a write readiness event is received.

This only clears writable readiness. HUP (on platforms that support HUP) cannot be cleared as it is a final state.

After calling this function, poll_write_ready(Ready::writable()) will return NotReady until a new write readiness event has been received.

Panics

This function will panic if called from outside of a task context.

Trait Implementations

impl<E: Evented> Drop for PollEvented<E>[src]

impl<E: Evented + Debug> Debug for PollEvented<E>[src]

impl<E> Write for PollEvented<E> where
    E: Evented + Write
[src]

fn write_vectored(&mut self, bufs: &[IoSlice]) -> Result<usize, Error>1.36.0[src]

Like write, except that it writes from a slice of buffers. Read more

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>1.0.0[src]

Attempts to write an entire buffer into this writer. Read more

fn write_fmt(&mut self, fmt: Arguments) -> Result<(), Error>1.0.0[src]

Writes a formatted string into this writer, returning any error encountered. Read more

fn by_ref(&mut self) -> &mut Self1.0.0[src]

Creates a "by reference" adaptor for this instance of Write. Read more

impl<'a, E> Write for &'a PollEvented<E> where
    E: Evented,
    &'a E: Write
[src]

fn write_vectored(&mut self, bufs: &[IoSlice]) -> Result<usize, Error>1.36.0[src]

Like write, except that it writes from a slice of buffers. Read more

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>1.0.0[src]

Attempts to write an entire buffer into this writer. Read more

fn write_fmt(&mut self, fmt: Arguments) -> Result<(), Error>1.0.0[src]

Writes a formatted string into this writer, returning any error encountered. Read more

fn by_ref(&mut self) -> &mut Self1.0.0[src]

Creates a "by reference" adaptor for this instance of Write. Read more

impl<E> Read for PollEvented<E> where
    E: Evented + Read
[src]

fn read_vectored(&mut self, bufs: &mut [IoSliceMut]) -> Result<usize, Error>1.36.0[src]

Like read, except that it reads into a slice of buffers. Read more

unsafe fn initializer(&self) -> Initializer[src]

🔬 This is a nightly-only experimental API. (read_initializer)

Determines if this Reader can work with buffers of uninitialized memory. Read more

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>1.0.0[src]

Read all bytes until EOF in this source, placing them into buf. Read more

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>1.0.0[src]

Read all bytes until EOF in this source, appending them to buf. Read more

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>1.6.0[src]

Read the exact number of bytes required to fill buf. Read more

fn by_ref(&mut self) -> &mut Self1.0.0[src]

Creates a "by reference" adaptor for this instance of Read. Read more

fn bytes(self) -> Bytes<Self>1.0.0[src]

Transforms this Read instance to an [Iterator] over its bytes. Read more

fn chain<R>(self, next: R) -> Chain<Self, R> where
    R: Read
1.0.0[src]

Creates an adaptor which will chain this stream with another. Read more

fn take(self, limit: u64) -> Take<Self>1.0.0[src]

Creates an adaptor which will read at most limit bytes from it. Read more

impl<'a, E> Read for &'a PollEvented<E> where
    E: Evented,
    &'a E: Read
[src]

fn read_vectored(&mut self, bufs: &mut [IoSliceMut]) -> Result<usize, Error>1.36.0[src]

Like read, except that it reads into a slice of buffers. Read more

unsafe fn initializer(&self) -> Initializer[src]

🔬 This is a nightly-only experimental API. (read_initializer)

Determines if this Reader can work with buffers of uninitialized memory. Read more

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>1.0.0[src]

Read all bytes until EOF in this source, placing them into buf. Read more

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>1.0.0[src]

Read all bytes until EOF in this source, appending them to buf. Read more

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>1.6.0[src]

Read the exact number of bytes required to fill buf. Read more

fn by_ref(&mut self) -> &mut Self1.0.0[src]

Creates a "by reference" adaptor for this instance of Read. Read more

fn bytes(self) -> Bytes<Self>1.0.0[src]

Transforms this Read instance to an [Iterator] over its bytes. Read more

fn chain<R>(self, next: R) -> Chain<Self, R> where
    R: Read
1.0.0[src]

Creates an adaptor which will chain this stream with another. Read more

fn take(self, limit: u64) -> Take<Self>1.0.0[src]

Creates an adaptor which will read at most limit bytes from it. Read more

impl<E> AsyncRead for PollEvented<E> where
    E: Evented + Read
[src]

unsafe fn prepare_uninitialized_buffer(&self, buf: &mut [u8]) -> bool[src]

Prepares an uninitialized buffer to be safe to pass to read. Returns true if the supplied buffer was zeroed out. Read more

fn poll_read(&mut self, buf: &mut [u8]) -> Result<Async<usize>, Error>[src]

Attempt to read from the AsyncRead into buf. Read more

fn read_buf<B>(&mut self, buf: &mut B) -> Result<Async<usize>, Error> where
    B: BufMut
[src]

Pull some bytes from this source into the specified BufMut, returning how many bytes were read. Read more

fn framed<T>(self, codec: T) -> Framed<Self, T> where
    Self: AsyncWrite,
    T: Decoder + Encoder, 
[src]

Deprecated since 0.1.7:

Use tokio_codec::Decoder::framed instead

Provides a Stream and Sink interface for reading and writing to this I/O object, using Decode and Encode to read and write the raw data. Read more

fn split(self) -> (ReadHalf<Self>, WriteHalf<Self>) where
    Self: AsyncWrite
[src]

Helper method for splitting this read/write object into two halves. Read more

impl<'a, E> AsyncRead for &'a PollEvented<E> where
    E: Evented,
    &'a E: Read
[src]

unsafe fn prepare_uninitialized_buffer(&self, buf: &mut [u8]) -> bool[src]

Prepares an uninitialized buffer to be safe to pass to read. Returns true if the supplied buffer was zeroed out. Read more

fn poll_read(&mut self, buf: &mut [u8]) -> Result<Async<usize>, Error>[src]

Attempt to read from the AsyncRead into buf. Read more

fn read_buf<B>(&mut self, buf: &mut B) -> Result<Async<usize>, Error> where
    B: BufMut
[src]

Pull some bytes from this source into the specified BufMut, returning how many bytes were read. Read more

fn framed<T>(self, codec: T) -> Framed<Self, T> where
    Self: AsyncWrite,
    T: Decoder + Encoder, 
[src]

Deprecated since 0.1.7:

Use tokio_codec::Decoder::framed instead

Provides a Stream and Sink interface for reading and writing to this I/O object, using Decode and Encode to read and write the raw data. Read more

fn split(self) -> (ReadHalf<Self>, WriteHalf<Self>) where
    Self: AsyncWrite
[src]

Helper method for splitting this read/write object into two halves. Read more

impl<E> AsyncWrite for PollEvented<E> where
    E: Evented + Write
[src]

fn poll_write(&mut self, buf: &[u8]) -> Result<Async<usize>, Error>[src]

Attempt to write bytes from buf into the object. Read more

fn poll_flush(&mut self) -> Result<Async<()>, Error>[src]

Attempt to flush the object, ensuring that any buffered data reach their destination. Read more

fn write_buf<B>(&mut self, buf: &mut B) -> Result<Async<usize>, Error> where
    B: Buf
[src]

Write a Buf into this value, returning how many bytes were written. Read more

impl<'a, E> AsyncWrite for &'a PollEvented<E> where
    E: Evented,
    &'a E: Write
[src]

fn poll_write(&mut self, buf: &[u8]) -> Result<Async<usize>, Error>[src]

Attempt to write bytes from buf into the object. Read more

fn poll_flush(&mut self) -> Result<Async<()>, Error>[src]

Attempt to flush the object, ensuring that any buffered data reach their destination. Read more

fn write_buf<B>(&mut self, buf: &mut B) -> Result<Async<usize>, Error> where
    B: Buf
[src]

Write a Buf into this value, returning how many bytes were written. Read more

Auto Trait Implementations

impl<E> Send for PollEvented<E> where
    E: Send

impl<E> Sync for PollEvented<E> where
    E: Sync

Blanket Implementations

impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

impl<T> Any for T where
    T: 'static + ?Sized
[src]

impl<T> Erased for T[src]

impl<R> ReadBytesExt for R where
    R: Read + ?Sized
[src]

fn read_u8(&mut self) -> Result<u8, Error>[src]

Reads an unsigned 8 bit integer from the underlying reader. Read more

fn read_i8(&mut self) -> Result<i8, Error>[src]

Reads a signed 8 bit integer from the underlying reader. Read more

fn read_u16<T>(&mut self) -> Result<u16, Error> where
    T: ByteOrder
[src]

Reads an unsigned 16 bit integer from the underlying reader. Read more

fn read_i16<T>(&mut self) -> Result<i16, Error> where
    T: ByteOrder
[src]

Reads a signed 16 bit integer from the underlying reader. Read more

fn read_u24<T>(&mut self) -> Result<u32, Error> where
    T: ByteOrder
[src]

Reads an unsigned 24 bit integer from the underlying reader. Read more

fn read_i24<T>(&mut self) -> Result<i32, Error> where
    T: ByteOrder
[src]

Reads a signed 24 bit integer from the underlying reader. Read more

fn read_u32<T>(&mut self) -> Result<u32, Error> where
    T: ByteOrder
[src]

Reads an unsigned 32 bit integer from the underlying reader. Read more

fn read_i32<T>(&mut self) -> Result<i32, Error> where
    T: ByteOrder
[src]

Reads a signed 32 bit integer from the underlying reader. Read more

fn read_u48<T>(&mut self) -> Result<u64, Error> where
    T: ByteOrder
[src]

Reads an unsigned 48 bit integer from the underlying reader. Read more

fn read_i48<T>(&mut self) -> Result<i64, Error> where
    T: ByteOrder
[src]

Reads a signed 48 bit integer from the underlying reader. Read more

fn read_u64<T>(&mut self) -> Result<u64, Error> where
    T: ByteOrder
[src]

Reads an unsigned 64 bit integer from the underlying reader. Read more

fn read_i64<T>(&mut self) -> Result<i64, Error> where
    T: ByteOrder
[src]

Reads a signed 64 bit integer from the underlying reader. Read more

fn read_u128<T>(&mut self) -> Result<u128, Error> where
    T: ByteOrder
[src]

Reads an unsigned 128 bit integer from the underlying reader. Read more

fn read_i128<T>(&mut self) -> Result<i128, Error> where
    T: ByteOrder
[src]

Reads a signed 128 bit integer from the underlying reader. Read more

fn read_uint<T>(&mut self, nbytes: usize) -> Result<u64, Error> where
    T: ByteOrder
[src]

Reads an unsigned n-bytes integer from the underlying reader. Read more

fn read_int<T>(&mut self, nbytes: usize) -> Result<i64, Error> where
    T: ByteOrder
[src]

Reads a signed n-bytes integer from the underlying reader. Read more

fn read_uint128<T>(&mut self, nbytes: usize) -> Result<u128, Error> where
    T: ByteOrder
[src]

Reads an unsigned n-bytes integer from the underlying reader.

fn read_int128<T>(&mut self, nbytes: usize) -> Result<i128, Error> where
    T: ByteOrder
[src]

Reads a signed n-bytes integer from the underlying reader.

fn read_f32<T>(&mut self) -> Result<f32, Error> where
    T: ByteOrder
[src]

Reads a IEEE754 single-precision (4 bytes) floating point number from the underlying reader. Read more

fn read_f64<T>(&mut self) -> Result<f64, Error> where
    T: ByteOrder
[src]

Reads a IEEE754 double-precision (8 bytes) floating point number from the underlying reader. Read more

fn read_u16_into<T>(&mut self, dst: &mut [u16]) -> Result<(), Error> where
    T: ByteOrder
[src]

Reads a sequence of unsigned 16 bit integers from the underlying reader. Read more

fn read_u32_into<T>(&mut self, dst: &mut [u32]) -> Result<(), Error> where
    T: ByteOrder
[src]

Reads a sequence of unsigned 32 bit integers from the underlying reader. Read more

fn read_u64_into<T>(&mut self, dst: &mut [u64]) -> Result<(), Error> where
    T: ByteOrder
[src]

Reads a sequence of unsigned 64 bit integers from the underlying reader. Read more

fn read_u128_into<T>(&mut self, dst: &mut [u128]) -> Result<(), Error> where
    T: ByteOrder
[src]

Reads a sequence of unsigned 128 bit integers from the underlying reader. Read more

fn read_i8_into(&mut self, dst: &mut [i8]) -> Result<(), Error>[src]

Reads a sequence of signed 8 bit integers from the underlying reader. Read more

fn read_i16_into<T>(&mut self, dst: &mut [i16]) -> Result<(), Error> where
    T: ByteOrder
[src]

Reads a sequence of signed 16 bit integers from the underlying reader. Read more

fn read_i32_into<T>(&mut self, dst: &mut [i32]) -> Result<(), Error> where
    T: ByteOrder
[src]

Reads a sequence of signed 32 bit integers from the underlying reader. Read more

fn read_i64_into<T>(&mut self, dst: &mut [i64]) -> Result<(), Error> where
    T: ByteOrder
[src]

Reads a sequence of signed 64 bit integers from the underlying reader. Read more

fn read_i128_into<T>(&mut self, dst: &mut [i128]) -> Result<(), Error> where
    T: ByteOrder
[src]

Reads a sequence of signed 128 bit integers from the underlying reader. Read more

fn read_f32_into<T>(&mut self, dst: &mut [f32]) -> Result<(), Error> where
    T: ByteOrder
[src]

Reads a sequence of IEEE754 single-precision (4 bytes) floating point numbers from the underlying reader. Read more

fn read_f32_into_unchecked<T>(&mut self, dst: &mut [f32]) -> Result<(), Error> where
    T: ByteOrder
[src]

Deprecated since 1.2.0:

please use read_f32_into instead

DEPRECATED. Read more

fn read_f64_into<T>(&mut self, dst: &mut [f64]) -> Result<(), Error> where
    T: ByteOrder
[src]

Reads a sequence of IEEE754 double-precision (8 bytes) floating point numbers from the underlying reader. Read more

fn read_f64_into_unchecked<T>(&mut self, dst: &mut [f64]) -> Result<(), Error> where
    T: ByteOrder
[src]

Deprecated since 1.2.0:

please use read_f64_into instead

DEPRECATED. Read more

impl<W> WriteBytesExt for W where
    W: Write + ?Sized
[src]

fn write_u8(&mut self, n: u8) -> Result<(), Error>[src]

Writes an unsigned 8 bit integer to the underlying writer. Read more

fn write_i8(&mut self, n: i8) -> Result<(), Error>[src]

Writes a signed 8 bit integer to the underlying writer. Read more

fn write_u16<T>(&mut self, n: u16) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes an unsigned 16 bit integer to the underlying writer. Read more

fn write_i16<T>(&mut self, n: i16) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes a signed 16 bit integer to the underlying writer. Read more

fn write_u24<T>(&mut self, n: u32) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes an unsigned 24 bit integer to the underlying writer. Read more

fn write_i24<T>(&mut self, n: i32) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes a signed 24 bit integer to the underlying writer. Read more

fn write_u32<T>(&mut self, n: u32) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes an unsigned 32 bit integer to the underlying writer. Read more

fn write_i32<T>(&mut self, n: i32) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes a signed 32 bit integer to the underlying writer. Read more

fn write_u48<T>(&mut self, n: u64) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes an unsigned 48 bit integer to the underlying writer. Read more

fn write_i48<T>(&mut self, n: i64) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes a signed 48 bit integer to the underlying writer. Read more

fn write_u64<T>(&mut self, n: u64) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes an unsigned 64 bit integer to the underlying writer. Read more

fn write_i64<T>(&mut self, n: i64) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes a signed 64 bit integer to the underlying writer. Read more

fn write_u128<T>(&mut self, n: u128) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes an unsigned 128 bit integer to the underlying writer.

fn write_i128<T>(&mut self, n: i128) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes a signed 128 bit integer to the underlying writer.

fn write_uint<T>(&mut self, n: u64, nbytes: usize) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes an unsigned n-bytes integer to the underlying writer. Read more

fn write_int<T>(&mut self, n: i64, nbytes: usize) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes a signed n-bytes integer to the underlying writer. Read more

fn write_uint128<T>(&mut self, n: u128, nbytes: usize) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes an unsigned n-bytes integer to the underlying writer. Read more

fn write_int128<T>(&mut self, n: i128, nbytes: usize) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes a signed n-bytes integer to the underlying writer. Read more

fn write_f32<T>(&mut self, n: f32) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes a IEEE754 single-precision (4 bytes) floating point number to the underlying writer. Read more

fn write_f64<T>(&mut self, n: f64) -> Result<(), Error> where
    T: ByteOrder
[src]

Writes a IEEE754 double-precision (8 bytes) floating point number to the underlying writer. Read more