binder: add async Rust support (05f5a2c4) · Commits · e / os / android_frameworks_native-old

libs/binder/rust/Android.bp

+21 −0

Original line number	Diff line number	Diff line
		@@ -32,6 +32,27 @@ rust_library {
		],
		}

		rust_library {
		name: "libbinder_tokio_rs",
		crate_name: "binder_tokio",
		srcs: ["binder_tokio/lib.rs"],
		rustlibs: [
		"libbinder_rs",
		"libtokio",
		],
		host_supported: true,
		target: {
		darwin: {
		enabled: false,
		}
		},
		apex_available: [
		"//apex_available:platform",
		"com.android.compos",
		"com.android.virt",
		],
		}

		rust_library {
		name: "libbinder_ndk_sys",
		crate_name: "binder_ndk_sys",

libs/binder/rust/binder_tokio/lib.rs

0 → 100644

+65 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2021 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		//! This crate lets you use the Tokio `spawn_blocking` pool with AIDL in async
		//! Rust code.
		//!
		//! This crate works by defining a type [`Tokio`], which you can use as the
		//! generic parameter in the async version of the trait generated by the AIDL
		//! compiler.
		//! ```text
		//! use binder_tokio::Tokio;
		//!
		//! binder::get_interface::<dyn SomeAsyncInterface<Tokio>>("...").
		//! ```
		//!
		//! [`Tokio`]: crate::Tokio

		use binder::public_api::{BinderAsyncPool, BoxFuture};
		use binder::StatusCode;
		use std::future::Future;

		/// Use the Tokio `spawn_blocking` pool with AIDL.
		pub enum Tokio {}

		impl BinderAsyncPool for Tokio {
		fn spawn<'a, F1, F2, Fut, A, B, E>(spawn_me: F1, after_spawn: F2) -> BoxFuture<'a, Result<B, E>>
		where
		F1: FnOnce() -> A,
		F2: FnOnce(A) -> Fut,
		Fut: Future<Output = Result<B, E>>,
		F1: Send + 'static,
		F2: Send + 'a,
		Fut: Send + 'a,
		A: Send + 'static,
		B: Send + 'a,
		E: From<crate::StatusCode>,
		{
		let handle = tokio::task::spawn_blocking(spawn_me);
		Box::pin(async move {
		// The `is_panic` branch is not actually reachable in Android as we compile
		// with `panic = abort`.
		match handle.await {
		Ok(res) => after_spawn(res).await,
		Err(e) if e.is_panic() => std::panic::resume_unwind(e.into_panic()),
		Err(e) if e.is_cancelled() => Err(StatusCode::FAILED_TRANSACTION.into()),
		Err(_) => Err(StatusCode::UNKNOWN_ERROR.into()),
		}
		})
		}
		}

libs/binder/rust/src/binder.rs

+78 −1

Original line number	Diff line number	Diff line
		@@ -713,12 +713,14 @@ macro_rules! declare_binder_interface {
		$interface:path[$descriptor:expr] {
		native: $native:ident($on_transact:path),
		proxy: $proxy:ident,
		$(async: $async_interface:ident,)?
		}
		} => {
		$crate::declare_binder_interface! {
		$interface[$descriptor] {
		native: $native($on_transact),
		proxy: $proxy {},
		$(async: $async_interface,)?
		stability: $crate::Stability::default(),
		}
		}
		@@ -728,6 +730,7 @@ macro_rules! declare_binder_interface {
		$interface:path[$descriptor:expr] {
		native: $native:ident($on_transact:path),
		proxy: $proxy:ident,
		$(async: $async_interface:ident,)?
		stability: $stability:expr,
		}
		} => {
		@@ -735,6 +738,7 @@ macro_rules! declare_binder_interface {
		$interface[$descriptor] {
		native: $native($on_transact),
		proxy: $proxy {},
		$(async: $async_interface,)?
		stability: $stability,
		}
		}
		@@ -746,6 +750,7 @@ macro_rules! declare_binder_interface {
		proxy: $proxy:ident {
		$($fname:ident: $fty:ty = $finit:expr),*
		},
		$(async: $async_interface:ident,)?
		}
		} => {
		$crate::declare_binder_interface! {
		@@ -754,6 +759,7 @@ macro_rules! declare_binder_interface {
		proxy: $proxy {
		$($fname: $fty = $finit),*
		},
		$(async: $async_interface,)?
		stability: $crate::Stability::default(),
		}
		}
		@@ -765,6 +771,7 @@ macro_rules! declare_binder_interface {
		proxy: $proxy:ident {
		$($fname:ident: $fty:ty = $finit:expr),*
		},
		$(async: $async_interface:ident,)?
		stability: $stability:expr,
		}
		} => {
		@@ -776,6 +783,7 @@ macro_rules! declare_binder_interface {
		proxy: $proxy {
		$($fname: $fty = $finit),*
		},
		$(async: $async_interface,)?
		stability: $stability,
		}
		}
		@@ -791,6 +799,8 @@ macro_rules! declare_binder_interface {
		$($fname:ident: $fty:ty = $finit:expr),*
		},

		$( async: $async_interface:ident, )?

		stability: $stability:expr,
		}
		} => {
		@@ -924,7 +934,7 @@ macro_rules! declare_binder_interface {
		}
		}

		impl std::fmt::Debug for dyn $interface {
		impl std::fmt::Debug for dyn $interface + '_ {
		fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
		f.pad(stringify!($interface))
		}
		@@ -938,6 +948,73 @@ macro_rules! declare_binder_interface {
		.expect(concat!("Error cloning interface ", stringify!($interface)))
		}
		}

		$(
		// Async interface trait implementations.
		impl<P: $crate::BinderAsyncPool> $crate::FromIBinder for dyn $async_interface<P> {
		fn try_from(mut ibinder: $crate::SpIBinder) -> $crate::Result<$crate::Strong<dyn $async_interface<P>>> {
		use $crate::AssociateClass;

		let existing_class = ibinder.get_class();
		if let Some(class) = existing_class {
		if class != <$native as $crate::Remotable>::get_class() &&
		class.get_descriptor() == <$native as $crate::Remotable>::get_descriptor()
		{
		// The binder object's descriptor string matches what we
		// expect. We still need to treat this local or already
		// associated object as remote, because we can't cast it
		// into a Rust service object without a matching class
		// pointer.
		return Ok($crate::Strong::new(Box::new(<$proxy as $crate::Proxy>::from_binder(ibinder)?)));
		}
		}

		if ibinder.associate_class(<$native as $crate::Remotable>::get_class()) {
		let service: $crate::Result<$crate::Binder<$native>> =
		std::convert::TryFrom::try_from(ibinder.clone());
		if let Ok(service) = service {
		// We were able to associate with our expected class and
		// the service is local.
		todo!()
		//return Ok($crate::Strong::new(Box::new(service)));
		} else {
		// Service is remote
		return Ok($crate::Strong::new(Box::new(<$proxy as $crate::Proxy>::from_binder(ibinder)?)));
		}
		}

		Err($crate::StatusCode::BAD_TYPE.into())
		}
		}

		impl<P: $crate::BinderAsyncPool> $crate::parcel::Serialize for dyn $async_interface<P> + '_ {
		fn serialize(&self, parcel: &mut $crate::parcel::Parcel) -> $crate::Result<()> {
		let binder = $crate::Interface::as_binder(self);
		parcel.write(&binder)
		}
		}

		impl<P: $crate::BinderAsyncPool> $crate::parcel::SerializeOption for dyn $async_interface<P> + '_ {
		fn serialize_option(this: Option<&Self>, parcel: &mut $crate::parcel::Parcel) -> $crate::Result<()> {
		parcel.write(&this.map($crate::Interface::as_binder))
		}
		}

		impl<P: $crate::BinderAsyncPool> std::fmt::Debug for dyn $async_interface<P> + '_ {
		fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
		f.pad(stringify!($async_interface))
		}
		}

		/// Convert a &dyn $async_interface to Strong<dyn $async_interface>
		impl<P: $crate::BinderAsyncPool> std::borrow::ToOwned for dyn $async_interface<P> {
		type Owned = $crate::Strong<dyn $async_interface<P>>;
		fn to_owned(&self) -> Self::Owned {
		self.as_binder().into_interface()
		.expect(concat!("Error cloning interface ", stringify!($async_interface)))
		}
		}
		)?
		};
		}

libs/binder/rust/src/binder_async.rs

0 → 100644

+55 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2021 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		use std::future::Future;
		use std::pin::Pin;

		/// A type alias for a pinned, boxed future that lets you write shorter code without littering it
		/// with Pin and Send bounds.
		pub type BoxFuture<'a, T> = Pin<Box<dyn Future<Output = T> + Send + 'a>>;

		/// A thread pool for running binder transactions.
		pub trait BinderAsyncPool {
		/// This function should conceptually behave like this:
		///
		/// ```text
		/// let result = spawn_thread(\|\| spawn_me()).await;
		/// return after_spawn(result).await;
		/// ```
		///
		/// If the spawning fails for some reason, the method may also skip the `after_spawn` closure
		/// and immediately return an error.
		///
		/// The only difference between different implementations should be which
		/// `spawn_thread` method is used. For Tokio, it would be `tokio::task::spawn_blocking`.
		///
		/// This method has the design it has because the only way to define a trait that
		/// allows the return type of the spawn to be chosen by the caller is to return a
		/// boxed `Future` trait object, and including `after_spawn` in the trait function
		/// allows the caller to avoid double-boxing if they want to do anything to the value
		/// returned from the spawned thread.
		fn spawn<'a, F1, F2, Fut, A, B, E>(spawn_me: F1, after_spawn: F2) -> BoxFuture<'a, Result<B, E>>
		where
		F1: FnOnce() -> A,
		F2: FnOnce(A) -> Fut,
		Fut: Future<Output = Result<B, E>>,
		F1: Send + 'static,
		F2: Send + 'a,
		Fut: Send + 'a,
		A: Send + 'static,
		B: Send + 'a,
		E: From<crate::StatusCode>;
		}

libs/binder/rust/src/lib.rs

+5 −2

Original line number	Diff line number	Diff line
		@@ -98,6 +98,7 @@ mod proxy;

		#[macro_use]
		mod binder;
		mod binder_async;
		mod error;
		mod native;
		mod state;
		@@ -111,6 +112,7 @@ pub use crate::binder::{
		Stability, Strong, TransactionCode, TransactionFlags, Weak, FIRST_CALL_TRANSACTION,
		FLAG_CLEAR_BUF, FLAG_ONEWAY, FLAG_PRIVATE_LOCAL, LAST_CALL_TRANSACTION,
		};
		pub use crate::binder_async::{BoxFuture, BinderAsyncPool};
		pub use error::{status_t, ExceptionCode, Result, Status, StatusCode};
		pub use native::{add_service, force_lazy_services_persist, register_lazy_service, Binder};
		pub use parcel::{OwnedParcel, Parcel};
		@@ -133,8 +135,9 @@ pub mod public_api {
		wait_for_interface,
		};
		pub use super::{
		BinderFeatures, DeathRecipient, ExceptionCode, IBinder, Interface, ProcessState, SpIBinder,
		Status, StatusCode, Strong, ThreadState, Weak, WpIBinder,
		BinderAsyncPool, BinderFeatures, BoxFuture, DeathRecipient, ExceptionCode, IBinder,
		Interface, ProcessState, SpIBinder, Status, StatusCode, Strong, ThreadState, Weak,
		WpIBinder,
		};

		/// Binder result containing a [`Status`] on error.