Module tokio::executor [−] [src]

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 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 multithreaded. This module provides both.

current_thread: A single-threaded executor that support spawning tasks that are not Send. It guarantees that tasks will be executed on the same thread from which they are spawned.
thread_pool: A multi-threaded executor that maintains a pool of threads. Tasks are spawned to one of the threads in the pool and executed. The pool employs a work-stealing strategy for optimizing how tasks get spread across the available threads.

`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, the current_thread 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.

Modules

current_thread	Execute many tasks concurrently on the current thread.
thread_pool	Maintains a pool of threads across which the set of spawned tasks are executed.

Structs

DefaultExecutor	Executes futures on the default executor for the current execution context.
Spawn	Return value from the `spawn` function.
SpawnError	Errors returned by `Executor::spawn`.

Traits

Executor

A value that executes futures.

Functions

spawn