libbinder_rs: Add Strong<> and Weak<> Binder references
Adds Strong<dyn Interface> and Weak<dyn Interface> references for Binder
interfaces. These structs are equivalent to sp<Interface> and
wp<Interface> in C++.
Bug: 175584883
Test: atest -p frameworks/native/libs/binder/TEST_MAPPING
Change-Id: Icf1b3acf0d8c82d541281a5aae9814372a5ab800
diff --git a/libs/binder/rust/src/proxy.rs b/libs/binder/rust/src/proxy.rs
index e9e74c0..132e075 100644
--- a/libs/binder/rust/src/proxy.rs
+++ b/libs/binder/rust/src/proxy.rs
@@ -17,7 +17,7 @@
//! Rust API for interacting with a remote binder service.
use crate::binder::{
- AsNative, FromIBinder, IBinder, Interface, InterfaceClass, TransactionCode, TransactionFlags,
+ AsNative, FromIBinder, IBinder, Interface, InterfaceClass, Strong, TransactionCode, TransactionFlags,
};
use crate::error::{status_result, Result, StatusCode};
use crate::parcel::{
@@ -27,6 +27,7 @@
use crate::sys;
use std::convert::TryInto;
+use std::cmp::Ordering;
use std::ffi::{c_void, CString};
use std::fmt;
use std::os::unix::io::AsRawFd;
@@ -99,7 +100,7 @@
///
/// If this object does not implement the expected interface, the error
/// `StatusCode::BAD_TYPE` is returned.
- pub fn into_interface<I: FromIBinder + ?Sized>(self) -> Result<Box<I>> {
+ pub fn into_interface<I: FromIBinder + Interface + ?Sized>(self) -> Result<Strong<I>> {
FromIBinder::try_from(self)
}
@@ -148,6 +149,36 @@
}
}
+impl Ord for SpIBinder {
+ fn cmp(&self, other: &Self) -> Ordering {
+ let less_than = unsafe {
+ // Safety: SpIBinder always holds a valid `AIBinder` pointer, so
+ // this pointer is always safe to pass to `AIBinder_lt` (null is
+ // also safe to pass to this function, but we should never do that).
+ sys::AIBinder_lt(self.0, other.0)
+ };
+ let greater_than = unsafe {
+ // Safety: SpIBinder always holds a valid `AIBinder` pointer, so
+ // this pointer is always safe to pass to `AIBinder_lt` (null is
+ // also safe to pass to this function, but we should never do that).
+ sys::AIBinder_lt(other.0, self.0)
+ };
+ if !less_than && !greater_than {
+ Ordering::Equal
+ } else if less_than {
+ Ordering::Less
+ } else {
+ Ordering::Greater
+ }
+ }
+}
+
+impl PartialOrd for SpIBinder {
+ fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+ Some(self.cmp(other))
+ }
+}
+
impl PartialEq for SpIBinder {
fn eq(&self, other: &Self) -> bool {
ptr::eq(self.0, other.0)
@@ -326,7 +357,7 @@
// Safety: `SpIBinder` guarantees that `self` always contains a
// valid pointer to an `AIBinder`. `recipient` can always be
// converted into a valid pointer to an
- // `AIBinder_DeatRecipient`. Any value is safe to pass as the
+ // `AIBinder_DeathRecipient`. Any value is safe to pass as the
// cookie, although we depend on this value being set by
// `get_cookie` when the death recipient callback is called.
sys::AIBinder_linkToDeath(
@@ -342,7 +373,7 @@
// Safety: `SpIBinder` guarantees that `self` always contains a
// valid pointer to an `AIBinder`. `recipient` can always be
// converted into a valid pointer to an
- // `AIBinder_DeatRecipient`. Any value is safe to pass as the
+ // `AIBinder_DeathRecipient`. Any value is safe to pass as the
// cookie, although we depend on this value being set by
// `get_cookie` when the death recipient callback is called.
sys::AIBinder_unlinkToDeath(
@@ -430,6 +461,62 @@
}
}
+impl Clone for WpIBinder {
+ fn clone(&self) -> Self {
+ let ptr = unsafe {
+ // Safety: WpIBinder always holds a valid `AIBinder_Weak` pointer,
+ // so this pointer is always safe to pass to `AIBinder_Weak_clone`
+ // (although null is also a safe value to pass to this API).
+ //
+ // We get ownership of the returned pointer, so can construct a new
+ // WpIBinder object from it.
+ sys::AIBinder_Weak_clone(self.0)
+ };
+ assert!(!ptr.is_null(), "Unexpected null pointer from AIBinder_Weak_clone");
+ Self(ptr)
+ }
+}
+
+impl Ord for WpIBinder {
+ fn cmp(&self, other: &Self) -> Ordering {
+ let less_than = unsafe {
+ // Safety: WpIBinder always holds a valid `AIBinder_Weak` pointer,
+ // so this pointer is always safe to pass to `AIBinder_Weak_lt`
+ // (null is also safe to pass to this function, but we should never
+ // do that).
+ sys::AIBinder_Weak_lt(self.0, other.0)
+ };
+ let greater_than = unsafe {
+ // Safety: WpIBinder always holds a valid `AIBinder_Weak` pointer,
+ // so this pointer is always safe to pass to `AIBinder_Weak_lt`
+ // (null is also safe to pass to this function, but we should never
+ // do that).
+ sys::AIBinder_Weak_lt(other.0, self.0)
+ };
+ if !less_than && !greater_than {
+ Ordering::Equal
+ } else if less_than {
+ Ordering::Less
+ } else {
+ Ordering::Greater
+ }
+ }
+}
+
+impl PartialOrd for WpIBinder {
+ fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+ Some(self.cmp(other))
+ }
+}
+
+impl PartialEq for WpIBinder {
+ fn eq(&self, other: &Self) -> bool {
+ self.cmp(other) == Ordering::Equal
+ }
+}
+
+impl Eq for WpIBinder {}
+
impl Drop for WpIBinder {
fn drop(&mut self) {
unsafe {
@@ -564,7 +651,7 @@
/// Retrieve an existing service for a particular interface, blocking for a few
/// seconds if it doesn't yet exist.
-pub fn get_interface<T: FromIBinder + ?Sized>(name: &str) -> Result<Box<T>> {
+pub fn get_interface<T: FromIBinder + ?Sized>(name: &str) -> Result<Strong<T>> {
let service = get_service(name);
match service {
Some(service) => FromIBinder::try_from(service),