tag | 4c09322bf0cfc7564cc2f8df40dd1d0414e91f4c | |
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tagger | The Android Open Source Project <initial-contribution@android.com> | Fri May 26 06:17:24 2023 -0700 |
object | 28056d2de023bece25b3a8ec98309e20169efa01 |
aml_med_331712010
commit | 28056d2de023bece25b3a8ec98309e20169efa01 | [log] [tgz] |
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author | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Mon May 09 20:35:18 2022 +0000 |
committer | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Mon May 09 20:35:18 2022 +0000 |
tree | a8c0195dcd49ed82252eacb02eecc46b2bc3cc63 | |
parent | 3b9ccd1daed9870e484cf8921cf349713d62d11b [diff] | |
parent | de861550982f984d861521fdde94390d4eb60003 [diff] |
Snap for 8562061 from de861550982f984d861521fdde94390d4eb60003 to mainline-media-release Change-Id: I2c5c8a20186a847c4bf8ed736f0f16915f2d0fc5
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.