Merge "Revert "[binder] Expose public Rust API at crate top level"" am: dd63c88f4e (46ea1d02) · Commits · e / os / android_frameworks_native

libs/binder/rust/binder_tokio/lib.rs

+6 −6

Original line number	Diff line number	Diff line
		@@ -28,8 +28,8 @@
		//!
		//! [`Tokio`]: crate::Tokio

		use binder::{BinderAsyncPool, BoxFuture, FromIBinder, StatusCode, Strong};
		use binder::binder_impl::BinderAsyncRuntime;
		use binder::public_api::{BinderAsyncPool, BoxFuture, Strong};
		use binder::{FromIBinder, StatusCode, BinderAsyncRuntime};
		use std::future::Future;

		/// Retrieve an existing service for a particular interface, sleeping for a few
		@@ -37,12 +37,12 @@ use std::future::Future;
		pub async fn get_interface<T: FromIBinder + ?Sized + 'static>(name: &str) -> Result<Strong<T>, StatusCode> {
		if binder::is_handling_transaction() {
		// See comment in the BinderAsyncPool impl.
		return binder::get_interface::<T>(name);
		return binder::public_api::get_interface::<T>(name);
		}

		let name = name.to_string();
		let res = tokio::task::spawn_blocking(move \|\| {
		binder::get_interface::<T>(&name)
		binder::public_api::get_interface::<T>(&name)
		}).await;

		// The `is_panic` branch is not actually reachable in Android as we compile
		@@ -61,12 +61,12 @@ pub async fn get_interface<T: FromIBinder + ?Sized + 'static>(name: &str) -> Res
		pub async fn wait_for_interface<T: FromIBinder + ?Sized + 'static>(name: &str) -> Result<Strong<T>, StatusCode> {
		if binder::is_handling_transaction() {
		// See comment in the BinderAsyncPool impl.
		return binder::wait_for_interface::<T>(name);
		return binder::public_api::wait_for_interface::<T>(name);
		}

		let name = name.to_string();
		let res = tokio::task::spawn_blocking(move \|\| {
		binder::wait_for_interface::<T>(&name)
		binder::public_api::wait_for_interface::<T>(&name)
		}).await;

		// The `is_panic` branch is not actually reachable in Android as we compile

libs/binder/rust/src/binder.rs

+53 −53

Original line number	Diff line number	Diff line
		@@ -536,13 +536,13 @@ impl<I: FromIBinder + ?Sized> Eq for Weak<I> {}
		/// ```
		macro_rules! binder_fn_get_class {
		($class:ty) => {
		binder_fn_get_class!($crate::binder_impl::InterfaceClass::new::<$class>());
		binder_fn_get_class!($crate::InterfaceClass::new::<$class>());
		};

		($constructor:expr) => {
		fn get_class() -> $crate::binder_impl::InterfaceClass {
		fn get_class() -> $crate::InterfaceClass {
		static CLASS_INIT: std::sync::Once = std::sync::Once::new();
		static mut CLASS: Option<$crate::binder_impl::InterfaceClass> = None;
		static mut CLASS: Option<$crate::InterfaceClass> = None;

		CLASS_INIT.call_once(\|\| unsafe {
		// Safety: This assignment is guarded by the `CLASS_INIT` `Once`
		@@ -772,7 +772,7 @@ macro_rules! declare_binder_interface {
		native: $native($on_transact),
		proxy: $proxy {},
		$(async: $async_interface,)?
		stability: $crate::binder_impl::Stability::default(),
		stability: $crate::Stability::default(),
		}
		}
		};
		@@ -811,7 +811,7 @@ macro_rules! declare_binder_interface {
		$($fname: $fty = $finit),*
		},
		$(async: $async_interface,)?
		stability: $crate::binder_impl::Stability::default(),
		stability: $crate::Stability::default(),
		}
		}
		};
		@@ -828,9 +828,9 @@ macro_rules! declare_binder_interface {
		} => {
		$crate::declare_binder_interface! {
		$interface[$descriptor] {
		@doc[concat!("A binder [`Remotable`]($crate::binder_impl::Remotable) that holds an [`", stringify!($interface), "`] object.")]
		@doc[concat!("A binder [`Remotable`]($crate::Remotable) that holds an [`", stringify!($interface), "`] object.")]
		native: $native($on_transact),
		@doc[concat!("A binder [`Proxy`]($crate::binder_impl::Proxy) that holds an [`", stringify!($interface), "`] remote interface.")]
		@doc[concat!("A binder [`Proxy`]($crate::Proxy) that holds an [`", stringify!($interface), "`] remote interface.")]
		proxy: $proxy {
		$($fname: $fty = $finit),*
		},
		@@ -867,7 +867,7 @@ macro_rules! declare_binder_interface {
		}
		}

		impl $crate::binder_impl::Proxy for $proxy
		impl $crate::Proxy for $proxy
		where
		$proxy: $interface,
		{
		@@ -875,7 +875,7 @@ macro_rules! declare_binder_interface {
		$descriptor
		}

		fn from_binder(mut binder: $crate::SpIBinder) -> std::result::Result<Self, $crate::StatusCode> {
		fn from_binder(mut binder: $crate::SpIBinder) -> $crate::Result<Self> {
		Ok(Self { binder, $($fname: $finit),* })
		}
		}
		@@ -887,19 +887,19 @@ macro_rules! declare_binder_interface {
		impl $native {
		/// Create a new binder service.
		pub fn new_binder<T: $interface + Sync + Send + 'static>(inner: T, features: $crate::BinderFeatures) -> $crate::Strong<dyn $interface> {
		let mut binder = $crate::binder_impl::Binder::new_with_stability($native(Box::new(inner)), $stability);
		let mut binder = $crate::Binder::new_with_stability($native(Box::new(inner)), $stability);
		#[cfg(not(android_vndk))]
		$crate::binder_impl::IBinderInternal::set_requesting_sid(&mut binder, features.set_requesting_sid);
		$crate::IBinderInternal::set_requesting_sid(&mut binder, features.set_requesting_sid);
		$crate::Strong::new(Box::new(binder))
		}
		}

		impl $crate::binder_impl::Remotable for $native {
		impl $crate::Remotable for $native {
		fn get_descriptor() -> &'static str {
		$descriptor
		}

		fn on_transact(&self, code: $crate::binder_impl::TransactionCode, data: &$crate::binder_impl::BorrowedParcel<'_>, reply: &mut $crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<(), $crate::StatusCode> {
		fn on_transact(&self, code: $crate::TransactionCode, data: &$crate::BorrowedParcel<'_>, reply: &mut $crate::BorrowedParcel<'_>) -> $crate::Result<()> {
		match $on_transact(&*self.0, code, data, reply) {
		// The C++ backend converts UNEXPECTED_NULL into an exception
		Err($crate::StatusCode::UNEXPECTED_NULL) => {
		@@ -913,19 +913,19 @@ macro_rules! declare_binder_interface {
		}
		}

		fn on_dump(&self, file: &std::fs::File, args: &[&std::ffi::CStr]) -> std::result::Result<(), $crate::StatusCode> {
		fn on_dump(&self, file: &std::fs::File, args: &[&std::ffi::CStr]) -> $crate::Result<()> {
		self.0.dump(file, args)
		}

		fn get_class() -> $crate::binder_impl::InterfaceClass {
		fn get_class() -> $crate::InterfaceClass {
		static CLASS_INIT: std::sync::Once = std::sync::Once::new();
		static mut CLASS: Option<$crate::binder_impl::InterfaceClass> = None;
		static mut CLASS: Option<$crate::InterfaceClass> = None;

		CLASS_INIT.call_once(\|\| unsafe {
		// Safety: This assignment is guarded by the `CLASS_INIT` `Once`
		// variable, and therefore is thread-safe, as it can only occur
		// once.
		CLASS = Some($crate::binder_impl::InterfaceClass::new::<$crate::binder_impl::Binder<$native>>());
		CLASS = Some($crate::InterfaceClass::new::<$crate::Binder<$native>>());
		});
		unsafe {
		// Safety: The `CLASS` variable can only be mutated once, above,
		@@ -936,25 +936,25 @@ macro_rules! declare_binder_interface {
		}

		impl $crate::FromIBinder for dyn $interface {
		fn try_from(mut ibinder: $crate::SpIBinder) -> std::result::Result<$crate::Strong<dyn $interface>, $crate::StatusCode> {
		use $crate::binder_impl::AssociateClass;
		fn try_from(mut ibinder: $crate::SpIBinder) -> $crate::Result<$crate::Strong<dyn $interface>> {
		use $crate::AssociateClass;

		let existing_class = ibinder.get_class();
		if let Some(class) = existing_class {
		if class != <$native as $crate::binder_impl::Remotable>::get_class() &&
		class.get_descriptor() == <$native as $crate::binder_impl::Remotable>::get_descriptor()
		if class != <$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 $crate::binder_impl::Proxy>::from_binder(ibinder)?)));
		return Ok($crate::Strong::new(Box::new(<$proxy as $crate::Proxy>::from_binder(ibinder)?)));
		}
		}

		if ibinder.associate_class(<$native as $crate::binder_impl::Remotable>::get_class()) {
		let service: std::result::Result<$crate::binder_impl::Binder<$native>, $crate::StatusCode> =
		if ibinder.associate_class(<$native as $crate::Remotable>::get_class()) {
		let service: $crate::Result<$crate::Binder<$native>> =
		std::convert::TryFrom::try_from(ibinder.clone());
		if let Ok(service) = service {
		// We were able to associate with our expected class and
		@@ -962,7 +962,7 @@ macro_rules! declare_binder_interface {
		return Ok($crate::Strong::new(Box::new(service)));
		} else {
		// Service is remote
		return Ok($crate::Strong::new(Box::new(<$proxy as $crate::binder_impl::Proxy>::from_binder(ibinder)?)));
		return Ok($crate::Strong::new(Box::new(<$proxy as $crate::Proxy>::from_binder(ibinder)?)));
		}
		}

		@@ -970,18 +970,18 @@ macro_rules! declare_binder_interface {
		}
		}

		impl $crate::binder_impl::Serialize for dyn $interface + '_
		impl $crate::parcel::Serialize for dyn $interface + '_
		where
		dyn $interface: $crate::Interface
		{
		fn serialize(&self, parcel: &mut $crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<(), $crate::StatusCode> {
		fn serialize(&self, parcel: &mut $crate::parcel::BorrowedParcel<'_>) -> $crate::Result<()> {
		let binder = $crate::Interface::as_binder(self);
		parcel.write(&binder)
		}
		}

		impl $crate::binder_impl::SerializeOption for dyn $interface + '_ {
		fn serialize_option(this: Option<&Self>, parcel: &mut $crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<(), $crate::StatusCode> {
		impl $crate::parcel::SerializeOption for dyn $interface + '_ {
		fn serialize_option(this: Option<&Self>, parcel: &mut $crate::parcel::BorrowedParcel<'_>) -> $crate::Result<()> {
		parcel.write(&this.map($crate::Interface::as_binder))
		}
		}
		@@ -1004,25 +1004,25 @@ macro_rules! declare_binder_interface {
		$(
		// Async interface trait implementations.
		impl<P: $crate::BinderAsyncPool> $crate::FromIBinder for dyn $async_interface<P> {
		fn try_from(mut ibinder: $crate::SpIBinder) -> std::result::Result<$crate::Strong<dyn $async_interface<P>>, $crate::StatusCode> {
		use $crate::binder_impl::AssociateClass;
		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 $crate::binder_impl::Remotable>::get_class() &&
		class.get_descriptor() == <$native as $crate::binder_impl::Remotable>::get_descriptor()
		if class != <$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 $crate::binder_impl::Proxy>::from_binder(ibinder)?)));
		return Ok($crate::Strong::new(Box::new(<$proxy as $crate::Proxy>::from_binder(ibinder)?)));
		}
		}

		if ibinder.associate_class(<$native as $crate::binder_impl::Remotable>::get_class()) {
		let service: std::result::Result<$crate::binder_impl::Binder<$native>, $crate::StatusCode> =
		if ibinder.associate_class(<$native as $crate::Remotable>::get_class()) {
		let service: $crate::Result<$crate::Binder<$native>> =
		std::convert::TryFrom::try_from(ibinder.clone());
		if let Ok(service) = service {
		// We were able to associate with our expected class and
		@@ -1031,7 +1031,7 @@ macro_rules! declare_binder_interface {
		//return Ok($crate::Strong::new(Box::new(service)));
		} else {
		// Service is remote
		return Ok($crate::Strong::new(Box::new(<$proxy as $crate::binder_impl::Proxy>::from_binder(ibinder)?)));
		return Ok($crate::Strong::new(Box::new(<$proxy as $crate::Proxy>::from_binder(ibinder)?)));
		}
		}

		@@ -1039,15 +1039,15 @@ macro_rules! declare_binder_interface {
		}
		}

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

		impl<P: $crate::BinderAsyncPool> $crate::binder_impl::SerializeOption for dyn $async_interface<P> + '_ {
		fn serialize_option(this: Option<&Self>, parcel: &mut $crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<(), $crate::StatusCode> {
		impl<P: $crate::BinderAsyncPool> $crate::parcel::SerializeOption for dyn $async_interface<P> + '_ {
		fn serialize_option(this: Option<&Self>, parcel: &mut $crate::parcel::BorrowedParcel<'_>) -> $crate::Result<()> {
		parcel.write(&this.map($crate::Interface::as_binder))
		}
		}
		@@ -1067,11 +1067,11 @@ macro_rules! declare_binder_interface {
		}
		}

		impl<P: $crate::BinderAsyncPool> $crate::binder_impl::ToAsyncInterface<P> for dyn $interface {
		impl<P: $crate::BinderAsyncPool> $crate::ToAsyncInterface<P> for dyn $interface {
		type Target = dyn $async_interface<P>;
		}

		impl<P: $crate::BinderAsyncPool> $crate::binder_impl::ToSyncInterface for dyn $async_interface<P> {
		impl<P: $crate::BinderAsyncPool> $crate::ToSyncInterface for dyn $async_interface<P> {
		type Target = dyn $interface;
		}
		)?
		@@ -1103,29 +1103,29 @@ macro_rules! declare_binder_enum {
		}
		}

		impl $crate::binder_impl::Serialize for $enum {
		fn serialize(&self, parcel: &mut $crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<(), $crate::StatusCode> {
		impl $crate::parcel::Serialize for $enum {
		fn serialize(&self, parcel: &mut $crate::parcel::BorrowedParcel<'_>) -> $crate::Result<()> {
		parcel.write(&self.0)
		}
		}

		impl $crate::binder_impl::SerializeArray for $enum {
		fn serialize_array(slice: &[Self], parcel: &mut $crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<(), $crate::StatusCode> {
		impl $crate::parcel::SerializeArray for $enum {
		fn serialize_array(slice: &[Self], parcel: &mut $crate::parcel::BorrowedParcel<'_>) -> $crate::Result<()> {
		let v: Vec<$backing> = slice.iter().map(\|x\| x.0).collect();
		<$backing as $crate::binder_impl::SerializeArray>::serialize_array(&v[..], parcel)
		<$backing as binder::parcel::SerializeArray>::serialize_array(&v[..], parcel)
		}
		}

		impl $crate::binder_impl::Deserialize for $enum {
		fn deserialize(parcel: &$crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<Self, $crate::StatusCode> {
		impl $crate::parcel::Deserialize for $enum {
		fn deserialize(parcel: &$crate::parcel::BorrowedParcel<'_>) -> $crate::Result<Self> {
		parcel.read().map(Self)
		}
		}

		impl $crate::binder_impl::DeserializeArray for $enum {
		fn deserialize_array(parcel: &$crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<Option<Vec<Self>>, $crate::StatusCode> {
		impl $crate::parcel::DeserializeArray for $enum {
		fn deserialize_array(parcel: &$crate::parcel::BorrowedParcel<'_>) -> $crate::Result<Option<Vec<Self>>> {
		let v: Option<Vec<$backing>> =
		<$backing as $crate::binder_impl::DeserializeArray>::deserialize_array(parcel)?;
		<$backing as binder::parcel::DeserializeArray>::deserialize_array(parcel)?;
		Ok(v.map(\|v\| v.into_iter().map(Self).collect()))
		}
		}

libs/binder/rust/src/lib.rs

+29 −34

Original line number	Diff line number	Diff line
		@@ -101,50 +101,45 @@ mod binder;
		mod binder_async;
		mod error;
		mod native;
		mod parcel;
		mod state;

		use binder_ndk_sys as sys;

		pub use binder::{BinderFeatures, FromIBinder, IBinder, Interface, Strong, Weak};
		pub use crate::binder_async::{BinderAsyncPool, BoxFuture};
		pub use error::{ExceptionCode, Status, StatusCode};
		pub use native::{
		add_service, force_lazy_services_persist, is_handling_transaction, register_lazy_service,
		};
		pub use parcel::{ParcelFileDescriptor, Parcelable, ParcelableHolder};
		pub use proxy::{
		get_interface, get_service, wait_for_interface, wait_for_service, DeathRecipient, SpIBinder,
		WpIBinder,
		};
		pub use state::{ProcessState, ThreadState};
		pub mod parcel;

		/// Binder result containing a [`Status`] on error.
		pub type Result<T> = std::result::Result<T, Status>;

		/// Advanced Binder APIs needed internally by AIDL or when manually using Binder
		/// without AIDL.
		pub mod binder_impl {
		pub use crate::binder::{
		IBinderInternal, InterfaceClass, Remotable, Stability, ToAsyncInterface, ToSyncInterface,
		TransactionCode, TransactionFlags, FIRST_CALL_TRANSACTION, FLAG_CLEAR_BUF, FLAG_ONEWAY,
		FLAG_PRIVATE_LOCAL, LAST_CALL_TRANSACTION,
		BinderFeatures, FromIBinder, IBinder, IBinderInternal, Interface, InterfaceClass, Remotable,
		Stability, Strong, ToAsyncInterface, ToSyncInterface, TransactionCode, TransactionFlags, Weak,
		FIRST_CALL_TRANSACTION, FLAG_CLEAR_BUF, FLAG_ONEWAY, FLAG_PRIVATE_LOCAL, LAST_CALL_TRANSACTION,
		};
		pub use crate::binder_async::BinderAsyncRuntime;
		pub use crate::error::status_t;
		pub use crate::native::Binder;
		pub use crate::parcel::{
		BorrowedParcel, Deserialize, DeserializeArray, DeserializeOption, Parcel,
		ParcelableMetadata, Serialize, SerializeArray, SerializeOption, NON_NULL_PARCELABLE_FLAG,
		NULL_PARCELABLE_FLAG,
		};
		pub use crate::proxy::{AssociateClass, Proxy};
		}
		pub use crate::binder_async::{BoxFuture, BinderAsyncPool, BinderAsyncRuntime};
		pub use error::{status_t, ExceptionCode, Result, Status, StatusCode};
		pub use native::{add_service, force_lazy_services_persist, is_handling_transaction, register_lazy_service, Binder};
		pub use parcel::{BorrowedParcel, Parcel};
		pub use proxy::{get_interface, get_service, wait_for_interface, wait_for_service};
		pub use proxy::{AssociateClass, DeathRecipient, Proxy, SpIBinder, WpIBinder};
		pub use state::{ProcessState, ThreadState};

		/// Unstable, in-development API that only allowlisted clients are allowed to use.
		#[doc(hidden)]
		pub mod unstable_api {
		pub use crate::binder::AsNative;
		pub use crate::proxy::unstable_api::new_spibinder;
		pub use crate::sys::AIBinder;
		}

		/// The public API usable outside AIDL-generated interface crates.
		pub mod public_api {
		pub use super::parcel::{ParcelFileDescriptor, ParcelableHolder};
		pub use super::{
		add_service, force_lazy_services_persist, get_interface, register_lazy_service,
		wait_for_interface,
		};
		pub use super::{
		BinderAsyncPool, BinderFeatures, BoxFuture, DeathRecipient, ExceptionCode, IBinder,
		Interface, ProcessState, SpIBinder, Status, StatusCode, Strong, ThreadState, Weak,
		WpIBinder,
		};

		/// Binder result containing a [`Status`] on error.
		pub type Result<T> = std::result::Result<T, Status>;
		}

libs/binder/rust/src/parcel/parcelable.rs

+33 −30

File changed.

Preview size limit exceeded, changes collapsed.

libs/binder/rust/src/parcel/parcelable_holder.rs

+6 −6

Original line number	Diff line number	Diff line
		@@ -15,8 +15,8 @@
		*/

		use crate::binder::Stability;
		use crate::error::StatusCode;
		use crate::parcel::{BorrowedParcel, Parcel, Parcelable};
		use crate::error::{Result, StatusCode};
		use crate::parcel::{Parcel, BorrowedParcel, Parcelable};
		use crate::{impl_deserialize_for_parcelable, impl_serialize_for_parcelable};

		use downcast_rs::{impl_downcast, DowncastSync};
		@@ -97,7 +97,7 @@ impl ParcelableHolder {
		}

		/// Set the parcelable contained in this `ParcelableHolder`.
		pub fn set_parcelable<T>(&mut self, p: Arc<T>) -> Result<(), StatusCode>
		pub fn set_parcelable<T>(&mut self, p: Arc<T>) -> Result<()>
		where
		T: Any + Parcelable + ParcelableMetadata + std::fmt::Debug + Send + Sync,
		{
		@@ -126,7 +126,7 @@ impl ParcelableHolder {
		/// * `Ok(None)` if the holder is empty or the descriptor does not match
		/// * `Ok(Some(_))` if the object holds a parcelable of type `T`
		/// with the correct descriptor
		pub fn get_parcelable<T>(&self) -> Result<Option<Arc<T>>, StatusCode>
		pub fn get_parcelable<T>(&self) -> Result<Option<Arc<T>>>
		where
		T: Any + Parcelable + ParcelableMetadata + Default + std::fmt::Debug + Send + Sync,
		{
		@@ -180,7 +180,7 @@ impl_serialize_for_parcelable!(ParcelableHolder);
		impl_deserialize_for_parcelable!(ParcelableHolder);

		impl Parcelable for ParcelableHolder {
		fn write_to_parcel(&self, parcel: &mut BorrowedParcel<'_>) -> Result<(), StatusCode> {
		fn write_to_parcel(&self, parcel: &mut BorrowedParcel<'_>) -> Result<()> {
		parcel.write(&self.stability)?;

		let mut data = self.data.lock().unwrap();
		@@ -219,7 +219,7 @@ impl Parcelable for ParcelableHolder {
		}
		}

		fn read_from_parcel(&mut self, parcel: &BorrowedParcel<'_>) -> Result<(), StatusCode> {
		fn read_from_parcel(&mut self, parcel: &BorrowedParcel<'_>) -> Result<()> {
		self.stability = parcel.read()?;

		let data_size: i32 = parcel.read()?;