commit | 2ad85522c71ec8e48d6a95999d41e33baa7a5202 | [log] [tgz] |
---|---|---|
author | Andrew Walbran <qwandor@google.com> | Wed Oct 18 18:53:27 2023 +0000 |
committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Wed Oct 18 18:53:27 2023 +0000 |
tree | 7da7ef40f6c8637accffeb7b81e80b2d09d382af | |
parent | 4d4b2dbe48f6647fef35390ae8a55c40eb9d2293 [diff] | |
parent | 93b21ad4eb068760edc99b11aaaee94bcc501159 [diff] |
Migrate to cargo_embargo. am: 93b21ad4eb Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/async-task/+/2796114 Change-Id: I5fd087b32230eefb971d6382b8b7257b17b7c8a4 Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
Task abstraction for building executors.
To spawn a future onto an executor, we first need to allocate it on the heap and keep some state attached to it. The state indicates whether the future is ready for polling, waiting to be woken up, or completed. Such a stateful future is called a task.
All executors have a queue that holds scheduled tasks:
let (sender, receiver) = flume::unbounded();
A task is created using either spawn()
, spawn_local()
, or spawn_unchecked()
which return a Runnable
and a Task
:
// A future that will be spawned. let future = async { 1 + 2 }; // A function that schedules the task when it gets woken up. let schedule = move |runnable| sender.send(runnable).unwrap(); // Construct a task. let (runnable, task) = async_task::spawn(future, schedule); // Push the task into the queue by invoking its schedule function. runnable.schedule();
The Runnable
is used to poll the task's future, and the Task
is used to await its output.
Finally, we need a loop that takes scheduled tasks from the queue and runs them:
for runnable in receiver { runnable.run(); }
Method run()
polls the task's future once. Then, the Runnable
vanishes and only reappears when its Waker
wakes the task, thus scheduling it to be run again.
Licensed under either of
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.