Crate futures_executor[−][src]
Built-in executors and related tools.
All asynchronous computation occurs within an executor, which is capable of spawning futures as tasks. This module provides several built-in executors, as well as tools for building your own.
All items are only available when the std
feature of this
library is activated, and it is activated by default.
Using a thread pool (M:N task scheduling)
Most of the time tasks should be executed on a thread pool.
A small set of worker threads can handle a very large set of spawned tasks
(which are much lighter weight than threads). Tasks spawned onto the pool
with the spawn_ok
function will run ambiently on
the created threads.
Spawning additional tasks
Tasks can be spawned onto a spawner by calling its spawn_obj
method
directly. In the case of !Send
futures, spawn_local_obj
can be used
instead.
Single-threaded execution
In addition to thread pools, it’s possible to run a task (and the tasks
it spawns) entirely within a single thread via the LocalPool
executor.
Aside from cutting down on synchronization costs, this executor also makes
it possible to spawn non-Send
tasks, via spawn_local_obj
. The
LocalPool
is best suited for running I/O-bound tasks that do relatively
little work between I/O operations.
There is also a convenience function block_on
for simply running a
future to completion on the current thread.
Structs
BlockingStream | An iterator which blocks on values from a stream until they become available. |
Enter | Represents an executor context. |
EnterError | An error returned by |
LocalPool | A single-threaded task pool for polling futures to completion. |
LocalSpawner | |
ThreadPool | A general-purpose thread pool for scheduling tasks that poll futures to completion. |
ThreadPoolBuilder | Thread pool configuration object. |
Functions
block_on | Run a future to completion on the current thread. |
block_on_stream | Turn a stream into a blocking iterator. |
enter | Marks the current thread as being within the dynamic extent of an executor. |