[][src]Module tokio::executor

Task execution utilities.

In the Tokio execution model, futures are lazy. When a future is created, no work is performed. In order for the work defined by the future to happen, the future must be submitted to an executor. A future that is submitted to an executor is called a "task".

The executor is responsible for ensuring that Future::poll is called whenever the task is notified. Notification happens when the internal state of a task transitions from "not ready" to ready. For example, a socket might have received data and a call to read will now be able to succeed.

The specific strategy used to manage the tasks is left up to the executor. There are two main flavors of executors: single-threaded and multi-threaded. Tokio provides implementation for both of these in the runtime module.

Executor trait.

This module provides the Executor trait (re-exported from tokio-executor), which describes the API that all executors must implement.

A free spawn function is provided that allows spawning futures onto the default executor (tracked via a thread-local variable) without referencing a handle. It is expected that all executors will set a value for the default executor. This value will often be set to the executor itself, but it is possible that the default executor might be set to a different executor.

For example, a single threaded executor might set the default executor to a thread pool instead of itself, allowing futures to spawn new tasks onto the thread pool when those tasks are Send.



Executes futures on the default executor for the current execution context.


Return value from the spawn function.


Errors returned by Executor::spawn.



A value that executes futures.


A value that spawns futures of a specific type.



Spawns a future on the default executor.