commit | 1de1ae62991cb3628e9faff46a757a62ac2491ca | [log] [tgz] |
---|---|---|
author | Matthew Maurer <mmaurer@google.com> | Tue May 31 19:05:48 2022 +0000 |
committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Tue May 31 19:05:48 2022 +0000 |
tree | 6119b3a0a16c22f62f0078cecb11493361e99954 | |
parent | 2d6697868ef5494610df28d72d3f524b4608302d [diff] | |
parent | c18c6a60bb3d8e4cf45beede0f30de86d5ff360c [diff] |
Update TEST_MAPPING am: 698295efe0 am: a7c63afe56 am: a4f6862903 am: 25c12102bb am: c18c6a60bb Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/async-task/+/2106888 Change-Id: I9744ab1aae19e13a350daa4f9c4a36300192252a 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.