rpc_binder: Mark ARpcServer_shutdown [[nodiscard]]

The function can fail. Propagate the return value from C++ to both C and
Rust wrappers.

Bug: 245727626
Test: builds
Change-Id: Idf6e6d9002119173d76fe25f73856a0768bb46a1

3 files changed, 9 insertions, 5 deletions

diff --git a/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp b/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp
index 311db2e3be..3ebbed6965 100644
--- a/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp
+++ b/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp
@@ -73,7 +73,7 @@ void ARpcServer_start(ARpcServer* server);
 void ARpcServer_join(ARpcServer* server);
 
 // Shuts down any running ARpcServer_join().
-void ARpcServer_shutdown(ARpcServer* server);
+[[nodiscard]] bool ARpcServer_shutdown(ARpcServer* server);
 
 // Frees the ARpcServer handle and drops the reference count on the underlying
 // RpcServer instance. The handle must not be reused afterwards.
diff --git a/libs/binder/libbinder_rpc_unstable.cpp b/libs/binder/libbinder_rpc_unstable.cpp
index 8886f7d856..89ef46d5c3 100644
--- a/libs/binder/libbinder_rpc_unstable.cpp
+++ b/libs/binder/libbinder_rpc_unstable.cpp
@@ -157,8 +157,8 @@ void ARpcServer_join(ARpcServer* handle) {
     handleToStrongPointer<RpcServer>(handle)->join();
 }
 
-void ARpcServer_shutdown(ARpcServer* handle) {
-    handleToStrongPointer<RpcServer>(handle)->shutdown();
+bool ARpcServer_shutdown(ARpcServer* handle) {
+    return handleToStrongPointer<RpcServer>(handle)->shutdown();
 }
 
 void ARpcServer_free(ARpcServer* handle) {
diff --git a/libs/binder/rust/rpcbinder/src/server.rs b/libs/binder/rust/rpcbinder/src/server.rs
index 73a2aa2f27..761b306a1e 100644
--- a/libs/binder/rust/rpcbinder/src/server.rs
+++ b/libs/binder/rust/rpcbinder/src/server.rs
@@ -140,7 +140,11 @@ impl RpcServerRef {
 
     /// Shuts down the running RpcServer. Can be called multiple times and from
     /// multiple threads. Called automatically during drop().
-    pub fn shutdown(&self) {
-        unsafe { binder_rpc_unstable_bindgen::ARpcServer_shutdown(self.as_ptr()) };
+    pub fn shutdown(&self) -> Result<(), Error> {
+        if unsafe { binder_rpc_unstable_bindgen::ARpcServer_shutdown(self.as_ptr()) } {
+            Ok(())
+        } else {
+            Err(Error::from(ErrorKind::UnexpectedEof))
+        }
     }
 }