Function tokio::spawn

Important traits for JoinHandle<T>

impl<T> Future for JoinHandle<T> type Output = Result<T, JoinError>;

pub fn spawn<T>(task: T) -> JoinHandle<T::Output> where
    T: Future + Send + 'static,
    T::Output: Send + 'static, 

Spawns a new asynchronous task, returning a JoinHandle] for it.

Spawning a task enables the task to execute concurrently to other tasks. The spawned task may execute on the current thread, or it may be sent to a different thread to be executed. The specifics depend on the current Runtime configuration.

Examples

In this example, a server is started and spawn is used to start a new task that processes each received connection.

use tokio::net::{TcpListener, TcpStream};

use std::io;

async fn process(socket: TcpStream) {
    // ...
}

#[tokio::main]
async fn main() -> io::Result<()> {
    let mut listener = TcpListener::bind("127.0.0.1:8080").await?;

    loop {
        let (socket, _) = listener.accept().await?;

        tokio::spawn(async move {
            // Process each socket concurrently.
            process(socket).await
        });
    }
}

Panics

Panics if called from outside of the Tokio runtime.