binder: host service manager limits max outgoing threads

... for each returned binder object. By default, the limit
is SIZE_MAX.

Test: aservice
  ... with max outgoing threads = 1, `aservice list` takes 19s.
  ... with max outgoing threads = SIZE_MAX, `aservice list` takes 30s.

Test: binderHostDeviceTest
Fixes: 194225767
Change-Id: Ib51fa41970fff804f40b7604a6a195ce0b16f89d
diff --git a/libs/binder/IServiceManager.cpp b/libs/binder/IServiceManager.cpp
index aff9e0d..81e61da 100644
--- a/libs/binder/IServiceManager.cpp
+++ b/libs/binder/IServiceManager.cpp
@@ -448,21 +448,27 @@
 // on-device service manager.
 class ServiceManagerHostShim : public ServiceManagerShim {
 public:
-    using ServiceManagerShim::ServiceManagerShim;
+    ServiceManagerHostShim(const sp<AidlServiceManager>& impl,
+                           const RpcDelegateServiceManagerOptions& options)
+          : ServiceManagerShim(impl), mOptions(options) {}
     // ServiceManagerShim::getService is based on checkService, so no need to override it.
     sp<IBinder> checkService(const String16& name) const override {
-        return getDeviceService({String8(name).c_str()});
+        return getDeviceService({String8(name).c_str()}, mOptions);
     }
 
 protected:
     // Override realGetService for ServiceManagerShim::waitForService.
     Status realGetService(const std::string& name, sp<IBinder>* _aidl_return) {
-        *_aidl_return = getDeviceService({"-g", name});
+        *_aidl_return = getDeviceService({"-g", name}, mOptions);
         return Status::ok();
     }
+
+private:
+    RpcDelegateServiceManagerOptions mOptions;
 };
-sp<IServiceManager> createRpcDelegateServiceManager() {
-    auto binder = getDeviceService({"manager"});
+sp<IServiceManager> createRpcDelegateServiceManager(
+        const RpcDelegateServiceManagerOptions& options) {
+    auto binder = getDeviceService({"manager"}, options);
     if (binder == nullptr) {
         ALOGE("getDeviceService(\"manager\") returns null");
         return nullptr;
@@ -472,7 +478,7 @@
         ALOGE("getDeviceService(\"manager\") returns non service manager");
         return nullptr;
     }
-    return sp<ServiceManagerHostShim>::make(interface);
+    return sp<ServiceManagerHostShim>::make(interface, options);
 }
 #endif
 
diff --git a/libs/binder/ServiceManagerHost.cpp b/libs/binder/ServiceManagerHost.cpp
index 27cc563..194254a 100644
--- a/libs/binder/ServiceManagerHost.cpp
+++ b/libs/binder/ServiceManagerHost.cpp
@@ -124,7 +124,8 @@
 
 } // namespace
 
-sp<IBinder> getDeviceService(std::vector<std::string>&& serviceDispatcherArgs) {
+sp<IBinder> getDeviceService(std::vector<std::string>&& serviceDispatcherArgs,
+                             const RpcDelegateServiceManagerOptions& options) {
     std::vector<std::string> prefix{"adb", "shell", "servicedispatcher"};
     serviceDispatcherArgs.insert(serviceDispatcherArgs.begin(), prefix.begin(), prefix.end());
 
@@ -158,6 +159,10 @@
     LOG_ALWAYS_FATAL_IF(!forwardResult->hostPort().has_value());
 
     auto rpcSession = RpcSession::make();
+    if (options.maxOutgoingThreads.has_value()) {
+        rpcSession->setMaxOutgoingThreads(*options.maxOutgoingThreads);
+    }
+
     if (status_t status = rpcSession->setupInetClient("127.0.0.1", *forwardResult->hostPort());
         status != OK) {
         ALOGE("Unable to set up inet client on host port %u: %s", *forwardResult->hostPort(),
diff --git a/libs/binder/ServiceManagerHost.h b/libs/binder/ServiceManagerHost.h
index e59724c..c5310da 100644
--- a/libs/binder/ServiceManagerHost.h
+++ b/libs/binder/ServiceManagerHost.h
@@ -21,11 +21,14 @@
 
 namespace android {
 
+struct RpcDelegateServiceManagerOptions;
+
 // Get a service on device by running servicedispatcher with the given args, e.g.
 //     getDeviceService({"foo"});
 // Return nullptr on any error.
 // When the returned binder object is destroyed, remove adb forwarding and kills
 // the long-running servicedispatcher process.
-sp<IBinder> getDeviceService(std::vector<std::string>&& serviceDispatcherArgs);
+sp<IBinder> getDeviceService(std::vector<std::string>&& serviceDispatcherArgs,
+                             const RpcDelegateServiceManagerOptions& options);
 
 } // namespace android
diff --git a/libs/binder/include/binder/IServiceManager.h b/libs/binder/include/binder/IServiceManager.h
index a48075d..240e3c2 100644
--- a/libs/binder/include/binder/IServiceManager.h
+++ b/libs/binder/include/binder/IServiceManager.h
@@ -188,7 +188,16 @@
 //        // ...
 //    }
 // Resources are cleaned up when the object is destroyed.
-sp<IServiceManager> createRpcDelegateServiceManager();
+//
+// For each returned binder object, at most |maxOutgoingThreads| outgoing threads are instantiated.
+// Hence, only |maxOutgoingThreads| calls can be made simultaneously. Additional calls are blocked
+// if there are |maxOutgoingThreads| ongoing calls. See RpcSession::setMaxOutgoingThreads.
+// If |maxOutgoingThreads| is not set, default is |RpcSession::kDefaultMaxOutgoingThreads|.
+struct RpcDelegateServiceManagerOptions {
+    std::optional<size_t> maxOutgoingThreads;
+};
+sp<IServiceManager> createRpcDelegateServiceManager(
+        const RpcDelegateServiceManagerOptions& options);
 #endif
 
 } // namespace android
diff --git a/libs/binder/tests/binderHostDeviceTest.cpp b/libs/binder/tests/binderHostDeviceTest.cpp
index eec3b44..464da60 100644
--- a/libs/binder/tests/binderHostDeviceTest.cpp
+++ b/libs/binder/tests/binderHostDeviceTest.cpp
@@ -65,7 +65,9 @@
 
 void initHostRpcServiceManagerOnce() {
     static std::once_flag gSmOnce;
-    std::call_once(gSmOnce, [] { setDefaultServiceManager(createRpcDelegateServiceManager()); });
+    std::call_once(gSmOnce, [] {
+        setDefaultServiceManager(createRpcDelegateServiceManager({.maxOutgoingThreads = 1}));
+    });
 }
 
 // Test for host service manager.