Struct tokio_core::reactor::PollEvented

pub struct PollEvented<E> {
    // some fields omitted
}

A concrete implementation of a stream of readiness notifications for I/O objects that originates from an event loop.

Created by the PollEvented::new method, each PollEvented is associated with a specific event loop and source of events that will be registered with an event loop.

Each readiness stream has a number of methods to test whether the underlying object is readable or writable. Once the methods return that an object is readable/writable, then it will continue to do so until the need_read or need_write methods are called.

That is, this object is typically wrapped in another form of I/O object. It's the responsibility of the wrapper to inform the readiness stream when a "would block" I/O event is seen. The readiness stream will then take care of any scheduling necessary to get notified when the event is ready again.

Methods

impl<E: Evented> PollEvented<E>

fn new(io: E, handle: &Handle) -> Result<PollEvented<E>>

Creates a new readiness stream associated with the provided loop_handle and for the given source.

This method returns a future which will resolve to the readiness stream when it's ready.

impl<E> PollEvented<E>

fn poll_read(&self) -> Async<()>

Tests to see if this source is ready to be read from or not.

If this stream is not ready for a read then NotReady will be returned and the current task will be scheduled to receive a notification when the stream is readable again. In other words, this method is only safe to call from within the context of a future's task, typically done in a Future::poll method.

fn poll_write(&self) -> Async<()>

Tests to see if this source is ready to be written to or not.

If this stream is not ready for a write then NotReady will be returned and the current task will be scheduled to receive a notification when the stream is writable again. In other words, this method is only safe to call from within the context of a future's task, typically done in a Future::poll method.

fn need_read(&self)

Indicates to this source of events that the corresponding I/O object is no longer readable, but it needs to be.

This function, like poll_read, is only safe to call from the context of a future's task (typically in a Future::poll implementation). It informs this readiness stream that the underlying object is no longer readable, typically because a "would block" error was seen.

The flag indicating that this stream is readable is unset and the current task is scheduled to receive a notification when the stream is then again readable.

fn need_write(&self)

Indicates to this source of events that the corresponding I/O object is no longer writable, but it needs to be.

This function, like poll_write, is only safe to call from the context of a future's task (typically in a Future::poll implementation). It informs this readiness stream that the underlying object is no longer writable, typically because a "would block" error was seen.

The flag indicating that this stream is writable is unset and the current task is scheduled to receive a notification when the stream is then again writable.

fn remote(&self) -> &Remote

Returns a reference to the event loop handle that this readiness stream is associated with.

fn get_ref(&self) -> &E

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

fn get_mut(&mut self) -> &mut E

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

Trait Implementations

impl<E: Read> Read for PollEvented<E>

fn read(&mut self, buf: &mut [u8]) -> Result<usize>

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

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

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

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

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

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

Read the exact number of bytes required to fill buf.

fn by_ref(&mut self) -> &mut Self

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

fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an Iterator over its bytes.

fn chars(self) -> Chars<Self>

Unstable (io)

: the semantics of a partial read/write of where errors happen is currently unclear and may change

Transforms this Read instance to an Iterator over chars.

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

Creates an adaptor which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

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

impl<E: Write> Write for PollEvented<E>

fn write(&mut self, buf: &[u8]) -> Result<usize>

Write a buffer into this object, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination.

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

Attempts to write an entire buffer into this write.

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

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

fn by_ref(&mut self) -> &mut Self

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

impl<E: Read + Write> Io for PollEvented<E>

fn poll_read(&mut self) -> Async<()>

Tests to see if this I/O object may be readable.

fn poll_write(&mut self) -> Async<()>

Tests to see if this I/O object may be writable.

fn split(self) -> (ReadHalf<Self>, WriteHalf<Self>) where Self: Sized

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

impl<'a, E> Read for &'a PollEvented<E> where &'a E: Read

fn read(&mut self, buf: &mut [u8]) -> Result<usize>

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

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

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

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

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

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

Read the exact number of bytes required to fill buf.

fn by_ref(&mut self) -> &mut Self

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

fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an Iterator over its bytes.

fn chars(self) -> Chars<Self>

Unstable (io)

: the semantics of a partial read/write of where errors happen is currently unclear and may change

Transforms this Read instance to an Iterator over chars.

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

Creates an adaptor which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

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

impl<'a, E> Write for &'a PollEvented<E> where &'a E: Write

fn write(&mut self, buf: &[u8]) -> Result<usize>

Write a buffer into this object, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination.

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

Attempts to write an entire buffer into this write.

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

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

fn by_ref(&mut self) -> &mut Self

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

impl<'a, E> Io for &'a PollEvented<E> where &'a E: Read + Write

fn poll_read(&mut self) -> Async<()>

Tests to see if this I/O object may be readable.

fn poll_write(&mut self) -> Async<()>

Tests to see if this I/O object may be writable.

fn split(self) -> (ReadHalf<Self>, WriteHalf<Self>) where Self: Sized

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

impl<E> Drop for PollEvented<E>

fn drop(&mut self)

A method called when the value goes out of scope.