Input-event-bridging service

The sole purpose of this service is the migration path from the use of
input session interface to the event session interface.

Issue #3812

repos/os/recipes/src/input_event_bridge/content.mk

@@ -0,0 +1,2 @@
+SRC_DIR = src/server/input_event_bridge
+include $(GENODE_DIR)/repos/base/recipes/src/content.inc

repos/os/recipes/src/input_event_bridge/hash

@@ -0,0 +1 @@
+2020-07-02 7738008ffb465e667621655e8718f02290361bc0

repos/os/recipes/src/input_event_bridge/used_apis

@@ -0,0 +1,4 @@
+base
+os
+event_session
+input_session

repos/os/src/server/input_event_bridge/main.cc

@@ -0,0 +1,96 @@
+/*
+ * \brief  Service for connecting an input client with an event client
+ * \author Norman Feske
+ * \date   2020-07-02
+ */
+
+/*
+ * Copyright (C) 2020 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU Affero General Public License version 3.
+ */
+
+/* Genode includes */
+#include <event_session/event_session.h>
+#include <input/component.h>
+#include <input/event.h>
+#include <os/static_root.h>
+#include <base/component.h>
+#include <base/attached_ram_dataspace.h>
+
+namespace Input_event_bridge {
+
+	using namespace Genode;
+
+	struct Event_session;
+	struct Main;
+}
+
+
+struct Input_event_bridge::Event_session : Rpc_object<Event::Session, Event_session>
+{
+	Attached_ram_dataspace _ds;
+
+	Input::Session_component &_input_session;
+
+	Dataspace_capability dataspace() { return _ds.cap(); }
+
+	void submit_batch(unsigned count)
+	{
+		size_t const max_events = _ds.size() / sizeof(Input::Event);
+
+		if (count > max_events)
+			warning("number of events exceeds dataspace capacity");
+
+		count = min(count, max_events);
+
+		Input::Event const * const events = _ds.local_addr<Input::Event>();
+
+		for (unsigned i = 0; i < count; i++)
+			_input_session.submit(events[i]);
+	}
+
+	Event_session(Env &env, Input::Session_component &input_session)
+	:
+		_ds(env.ram(), env.rm(), 4096), _input_session(input_session)
+	{ }
+};
+
+
+/******************
+ ** Main program **
+ ******************/
+
+struct Input_event_bridge::Main
+{
+	Env &_env;
+
+	Attached_ram_dataspace _ds { _env.ram(), _env.rm(), 4096 };
+
+	Input::Session_component _input_session { _env, _env.ram() };
+	Event_session            _event_session { _env, _input_session };
+
+	/*
+	 * Attach root interfaces to the entry point
+	 */
+	Static_root<Input::Session> _input_root { _env.ep().manage(_input_session) };
+	Static_root<Event::Session> _event_root { _env.ep().manage(_event_session) };
+
+	/**
+	 * Constructor
+	 */
+	Main(Env &env) : _env(env)
+	{
+		_input_session.event_queue().enabled(true);
+
+		_env.parent().announce(env.ep().manage(_input_root));
+		_env.parent().announce(env.ep().manage(_event_root));
+	}
+};
+
+
+void Component::construct(Genode::Env &env)
+{
+	static Input_event_bridge::Main inst(env);
+}

repos/os/src/server/input_event_bridge/target.mk

@@ -0,0 +1,3 @@
+TARGET = input_event_bridge
+SRC_CC = main.cc
+LIBS   = base