binder: add async Rust support
Test: add and run integration tests
Change-Id: I7671eeb7dfe4cc45efd57756753b361440529a3c
diff --git a/libs/binder/rust/src/binder.rs b/libs/binder/rust/src/binder.rs
index cc5dd06..4e048d7 100644
--- a/libs/binder/rust/src/binder.rs
+++ b/libs/binder/rust/src/binder.rs
@@ -713,12 +713,14 @@
$interface:path[$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 @@
$interface:path[$descriptor:expr] {
native: $native:ident($on_transact:path),
proxy: $proxy:ident,
+ $(async: $async_interface:ident,)?
stability: $stability:expr,
}
} => {
@@ -735,6 +738,7 @@
$interface[$descriptor] {
native: $native($on_transact),
proxy: $proxy {},
+ $(async: $async_interface,)?
stability: $stability,
}
}
@@ -746,6 +750,7 @@
proxy: $proxy:ident {
$($fname:ident: $fty:ty = $finit:expr),*
},
+ $(async: $async_interface:ident,)?
}
} => {
$crate::declare_binder_interface! {
@@ -754,6 +759,7 @@
proxy: $proxy {
$($fname: $fty = $finit),*
},
+ $(async: $async_interface,)?
stability: $crate::Stability::default(),
}
}
@@ -765,6 +771,7 @@
proxy: $proxy:ident {
$($fname:ident: $fty:ty = $finit:expr),*
},
+ $(async: $async_interface:ident,)?
stability: $stability:expr,
}
} => {
@@ -776,6 +783,7 @@
proxy: $proxy {
$($fname: $fty = $finit),*
},
+ $(async: $async_interface,)?
stability: $stability,
}
}
@@ -791,6 +799,8 @@
$($fname:ident: $fty:ty = $finit:expr),*
},
+ $( async: $async_interface:ident, )?
+
stability: $stability:expr,
}
} => {
@@ -924,7 +934,7 @@
}
}
- 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 @@
.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)))
+ }
+ }
+ )?
};
}
diff --git a/libs/binder/rust/src/binder_async.rs b/libs/binder/rust/src/binder_async.rs
new file mode 100644
index 0000000..214c0b5
--- /dev/null
+++ b/libs/binder/rust/src/binder_async.rs
@@ -0,0 +1,55 @@
+/*
+ * 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>;
+}
diff --git a/libs/binder/rust/src/lib.rs b/libs/binder/rust/src/lib.rs
index 81b620e..2ac2d2f 100644
--- a/libs/binder/rust/src/lib.rs
+++ b/libs/binder/rust/src/lib.rs
@@ -98,6 +98,7 @@
#[macro_use]
mod binder;
+mod binder_async;
mod error;
mod native;
mod state;
@@ -111,6 +112,7 @@
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 @@
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.
diff --git a/libs/binder/rust/src/parcel.rs b/libs/binder/rust/src/parcel.rs
index 9dba950..a0e1478 100644
--- a/libs/binder/rust/src/parcel.rs
+++ b/libs/binder/rust/src/parcel.rs
@@ -83,6 +83,19 @@
Self { ptr }
}
+ /// Convert the provided parcel to an owned parcel, or return `None` if it
+ /// is borrowed.
+ pub fn try_from(parcel: Parcel) -> Option<OwnedParcel> {
+ match &parcel {
+ Parcel::Owned(ptr) => {
+ let ptr = *ptr;
+ std::mem::forget(parcel);
+ Some(OwnedParcel { ptr })
+ }
+ Parcel::Borrowed(_) => None,
+ }
+ }
+
/// Create an owned reference to a parcel object from a raw pointer.
///
/// # Safety