std::sync::mpsc::SyncSender - Rust
Description: API documentation for the Rust `SyncSender` struct in crate `std`.
Keywords: rust, rustlang, rust-lang, SyncSender

# Struct std::sync::mpsc::SyncSender 1.0.0 [−] [src]

    pub struct SyncSender<T> { /* fields omitted */ }

The sending-half of Rust's synchronous `sync_channel` type.

Messages can be sent through this channel with `send` or `try_send`.

`send` will block if there is no space in the internal buffer.

# Examples

    use std::sync::mpsc::sync_channel;
    use std::thread;

    // Create a sync_channel with buffer size 2
    let (sync_sender, receiver) = sync_channel(2);
    let sync_sender2 = sync_sender.clone();

    // First thread owns sync_sender
    thread::spawn(move || {
        sync_sender.send(1).unwrap();
        sync_sender.send(2).unwrap();
    });

    // Second thread owns sync_sender2
    thread::spawn(move || {
        sync_sender2.send(3).unwrap();
        // thread will now block since the buffer is full
        println!("Thread unblocked!");
    });

    let mut msg;

    msg = receiver.recv().unwrap();
    println!("message {} received", msg);

    // "Thread unblocked!" will be printed now

    msg = receiver.recv().unwrap();
    println!("message {} received", msg);

    msg = receiver.recv().unwrap();

    println!("message {} received", msg);Run

## Methods

### `impl<T> SyncSender<T>`
[src]

#### `fn send(&self, t: T) -> Result<(), SendError<T>>`

Sends a value on this synchronous channel.

This function will block until space in the internal buffer becomes available or a receiver is available to hand off the message to.

Note that a successful send does not guarantee that the receiver will ever see the data if there is a buffer on this channel. Items may be enqueued in the internal buffer for the receiver to receive at a later time. If the buffer size is 0, however, the channel becomes a rendezvous channel and it guarantees that the receiver has indeed received the data if this function returns success.

This function will never panic, but it may return `Err` if the `Receiver` has disconnected and is no longer able to receive information.

# Examples

    use std::sync::mpsc::sync_channel;
    use std::thread;

    // Create a rendezvous sync_channel with buffer size 0
    let (sync_sender, receiver) = sync_channel(0);

    thread::spawn(move || {
       println!("sending message...");
       sync_sender.send(1).unwrap();
       // Thread is now blocked until the message is received

       println!("...message received!");
    });

    let msg = receiver.recv().unwrap();
    assert_eq!(1, msg);Run

#### `fn try_send(&self, t: T) -> Result<(), TrySendError<T>>`

Attempts to send a value on this channel without blocking.

This method differs from `send` by returning immediately if the channel's buffer is full or no receiver is waiting to acquire some data. Compared with `send`, this function has two failure cases instead of one (one for disconnection, one for a full buffer).

See `send` for notes about guarantees of whether the receiver has received the data or not if this function is successful.

# Examples

    use std::sync::mpsc::sync_channel;
    use std::thread;

    // Create a sync_channel with buffer size 1
    let (sync_sender, receiver) = sync_channel(1);
    let sync_sender2 = sync_sender.clone();

    // First thread owns sync_sender
    thread::spawn(move || {
        sync_sender.send(1).unwrap();
        sync_sender.send(2).unwrap();
        // Thread blocked
    });

    // Second thread owns sync_sender2
    thread::spawn(move || {
        // This will return an error and send
        // no message if the buffer is full
        sync_sender2.try_send(3).is_err();
    });

    let mut msg;
    msg = receiver.recv().unwrap();
    println!("message {} received", msg);

    msg = receiver.recv().unwrap();
    println!("message {} received", msg);

    // Third message may have never been sent
    match receiver.try_recv() {
        Ok(msg) => println!("message {} received", msg),
        Err(_) => println!("the third message was never sent"),
    }Run

## Trait Implementations

### `impl<T: Send> Send for SyncSender<T>`
[src]

### `impl<T> Clone for SyncSender<T>`
[src]

#### `fn clone(&self) -> SyncSender<T>`

Returns a copy of the value. Read more

#### `fn clone_from(&mut self, source: &Self)`

Performs copy-assignment from `source`. Read more

### `impl<T> Drop for SyncSender<T>`
[src]

#### `fn drop(&mut self)`

A method called when the value goes out of scope. Read more

### `impl<T> Debug for SyncSender<T>`
1.8.0
[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result`

Formats the value using the given formatter.

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