Expose RpcServer::setMaxThreads in BinderRpc Rust API.

Bug: 332776171
Test: manual
Change-Id: I6b284d93c35230f99350c77dff2b7bb7ad79dd87

3 files changed, 29 insertions, 0 deletions

diff --git a/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp b/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp
index 7d0acd1843..392ebb5b0a 100644
--- a/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp
+++ b/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp
@@ -73,6 +73,17 @@ void ARpcServer_setSupportedFileDescriptorTransportModes(
         const ARpcSession_FileDescriptorTransportMode modes[],
         size_t modes_len);
 
+// Sets the maximum number of threads that the Server will use for
+// incoming client connections.
+//
+// This must be called before adding a client session. This corresponds
+// to the number of incoming connections to RpcSession objects in the
+// server, which will correspond to the number of outgoing connections
+// in client RpcSession objects.
+//
+// If this is not specified, this will be a single-threaded server.
+void ARpcServer_setMaxThreads(ARpcServer* server, size_t threads);
+
 // Runs ARpcServer_join() in a background thread. Immediately returns.
 void ARpcServer_start(ARpcServer* server);
 
diff --git a/libs/binder/libbinder_rpc_unstable.cpp b/libs/binder/libbinder_rpc_unstable.cpp
index cb44c58c2c..21537fc50d 100644
--- a/libs/binder/libbinder_rpc_unstable.cpp
+++ b/libs/binder/libbinder_rpc_unstable.cpp
@@ -167,6 +167,10 @@ void ARpcServer_setSupportedFileDescriptorTransportModes(
     server->setSupportedFileDescriptorTransportModes(modevec);
 }
 
+void ARpcServer_setMaxThreads(ARpcServer* handle, size_t threads) {
+    handleToStrongPointer<RpcServer>(handle)->setMaxThreads(threads);
+}
+
 void ARpcServer_start(ARpcServer* handle) {
     handleToStrongPointer<RpcServer>(handle)->start();
 }
diff --git a/libs/binder/rust/rpcbinder/src/server/android.rs b/libs/binder/rust/rpcbinder/src/server/android.rs
index ad0365b505..2ab34472a9 100644
--- a/libs/binder/rust/rpcbinder/src/server/android.rs
+++ b/libs/binder/rust/rpcbinder/src/server/android.rs
@@ -147,6 +147,20 @@ impl RpcServerRef {
         }
     }
 
+    /// Sets the max number of threads this Server uses for incoming client connections.
+    ///
+    /// This must be called before adding a client session. This corresponds
+    /// to the number of incoming connections to RpcSession objects in the
+    /// server, which will correspond to the number of outgoing connections
+    /// in client RpcSession objects. Specifically this is useful for handling
+    /// client-side callback connections.
+    ///
+    /// If this is not specified, this will be a single-threaded server.
+    pub fn set_max_threads(&self, count: usize) {
+        // SAFETY: RpcServerRef wraps a valid pointer to an ARpcServer.
+        unsafe { binder_rpc_unstable_bindgen::ARpcServer_setMaxThreads(self.as_ptr(), count) };
+    }
+
     /// Starts a new background thread and calls join(). Returns immediately.
     pub fn start(&self) {
         // SAFETY: RpcServerRef wraps a valid pointer to an ARpcServer.