Struct actix_web::rt::Runtime

pub struct Runtime { /* private fields */ }

A Tokio-based runtime proxy.

All spawned futures will be executed on the current thread. Therefore, there is no Send bound on submitted futures.

Implementations

impl Runtime

pub fn new() -> Result<Runtime, Error>

Returns a new runtime initialized with default configuration values.

pub fn spawn<F>(&self, future: F) -> JoinHandle<<F as Future>::Output>

where F: Future + 'static,

Offload a future onto the single-threaded runtime.

The returned join handle can be used to await the future’s result.

See [crate root][crate] documentation for more details.

Examples

let rt = actix_rt::Runtime::new().unwrap();

// Spawn a future onto the runtime
let handle = rt.spawn(async {
    println!("running on the runtime");
    42
});

assert_eq!(rt.block_on(handle).unwrap(), 42);

Panics

This function panics if the spawn fails. Failure occurs if the executor is currently at capacity and is unable to spawn a new future.

pub fn tokio_runtime(&self) -> &Runtime

Retrieves a reference to the underlying Tokio runtime associated with this instance.

The Tokio runtime is responsible for executing asynchronous tasks and managing the event loop for an asynchronous Rust program. This method allows accessing the runtime to interact with its features directly.

In a typical use case, you might need to share the same runtime between different modules of your project. For example, a module might require a tokio::runtime::Handle to spawn tasks on the same runtime, or the runtime itself to configure more complex behaviours.

Example

use actix_rt::Runtime;

mod module_a {
    pub fn do_something(handle: tokio::runtime::Handle) {
        handle.spawn(async {
            // Some asynchronous task here
        });
    }
}

mod module_b {
    pub fn do_something_else(rt: &tokio::runtime::Runtime) {
        rt.spawn(async {
            // Another asynchronous task here
        });
    }
}

let actix_runtime = actix_rt::Runtime::new().unwrap();
let tokio_runtime = actix_runtime.tokio_runtime();

let handle = tokio_runtime.handle().clone();

module_a::do_something(handle);
module_b::do_something_else(tokio_runtime);

Returns

An immutable reference to the tokio::runtime::Runtime instance associated with this Runtime instance.

Note

While this method provides an immutable reference to the Tokio runtime, which is safe to share across threads, be aware that spawning blocking tasks on the Tokio runtime could potentially impact the execution of the Actix runtime. This is because Tokio is responsible for driving the Actix system, and blocking tasks could delay or deadlock other tasks in run loop.

pub fn block_on<F>(&self, f: F) -> <F as Future>::Output

where F: Future,

Runs the provided future, blocking the current thread until the future completes.

This function can be used to synchronously block the current thread until the provided future has resolved either successfully or with an error. The result of the future is then returned from this function call.

Note that this function will also execute any spawned futures on the current thread, but will not block until these other spawned futures have completed. Once the function returns, any uncompleted futures remain pending in the Runtime instance. These futures will not run until block_on or run is called again.

The caller is responsible for ensuring that other spawned futures complete execution by calling block_on or run.

Trait Implementations

impl Debug for Runtime

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl From<Runtime> for Runtime

fn from(rt: Runtime) -> Runtime

Converts to this type from the input type.