lib/dbus/Glue: singleton for global initialization

Makefile.am

@@ -293,6 +293,7 @@ libodbus_a_SOURCES = \
 	src/lib/dbus/ScopeMatch.cxx src/lib/dbus/ScopeMatch.hxx \
 	src/lib/dbus/Types.hxx \
 	src/lib/dbus/Values.hxx \
+	src/lib/dbus/Glue.cxx src/lib/dbus/Glue.hxx \
 	src/lib/dbus/Watch.cxx src/lib/dbus/Watch.hxx
 libodbus_a_CPPFLAGS = $(AM_CPPFLAGS) $(DBUS_CFLAGS)
 endif

src/lib/dbus/Glue.cxx

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2003-2018 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "Glue.hxx"
+
+namespace ODBus {
+
+void
+Glue::Connect()
+{
+	watch.SetConnection(Connection::GetSystem());
+
+	dbus_connection_set_exit_on_disconnect(GetConnection(), false);
+}
+
+void
+Glue::Disconnect()
+{
+	watch.SetConnection(Connection());
+}
+
+void
+Glue::OnDBusClosed() noexcept
+{
+	// TODO: reconnect
+}
+
+}

src/lib/dbus/Glue.hxx

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2003-2018 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_DBUS_GLUE_HXX
+#define MPD_DBUS_GLUE_HXX
+
+#include "Watch.hxx"
+
+class EventLoop;
+
+namespace ODBus {
+
+/**
+ * A class which manages the D-Bus client connection.
+ */
+class Glue final : ODBus::WatchManagerObserver {
+	WatchManager watch;
+
+public:
+	explicit Glue(EventLoop &event_loop)
+		:watch(event_loop, *this) {
+		Connect();
+	}
+
+	~Glue() noexcept {
+		Disconnect();
+	}
+
+	EventLoop &GetEventLoop() noexcept {
+		return watch.GetEventLoop();
+	}
+
+	Connection &GetConnection() noexcept {
+		return watch.GetConnection();
+	}
+
+private:
+	void Connect();
+	void Disconnect();
+
+	/* virtual methods from class ODBus::WatchManagerObserver */
+	void OnDBusClosed() noexcept override;
+};
+
+}
+
+#endif

src/neighbor/plugins/UdisksNeighborPlugin.cxx

@@ -21,7 +21,7 @@
 #include "UdisksNeighborPlugin.hxx"
 #include "lib/dbus/Connection.hxx"
 #include "lib/dbus/Error.hxx"
-#include "lib/dbus/Watch.hxx"
+#include "lib/dbus/Glue.hxx"
 #include "lib/dbus/Message.hxx"
 #include "lib/dbus/PendingCall.hxx"
 #include "lib/dbus/ReadIter.hxx"
@@ -34,6 +34,7 @@
 #include "thread/Mutex.hxx"
 #include "util/Domain.hxx"
 #include "util/StringAPI.hxx"
+#include "util/Manual.hxx"
 #include "Log.hxx"
 
 #include <stdexcept>
@@ -69,9 +70,11 @@ struct UdisksObject {
 };
 
 class UdisksNeighborExplorer final
-	: public NeighborExplorer, ODBus::WatchManagerObserver {
+	: public NeighborExplorer {
 
-	ODBus::WatchManager dbus_watch;
+	EventLoop &event_loop;
+
+	Manual<ODBus::Glue> dbus_glue;
 
 	ODBus::PendingCall pending_list_call;
 
@@ -85,13 +88,16 @@ class UdisksNeighborExplorer final
 	std::map<std::string, ByUri::iterator> by_path;
 
 public:
-	UdisksNeighborExplorer(EventLoop &event_loop,
+	UdisksNeighborExplorer(EventLoop &_event_loop,
 			       NeighborListener &_listener) noexcept
-		:NeighborExplorer(_listener),
-		 dbus_watch(event_loop, *this) {}
+		:NeighborExplorer(_listener), event_loop(_event_loop) {}
 
 	auto &GetEventLoop() noexcept {
-		return dbus_watch.GetEventLoop();
+		return event_loop;
+	}
+
+	auto &&GetConnection() noexcept {
+		return dbus_glue->GetConnection();
 	}
 
 	/* virtual methods from class NeighborExplorer */
@@ -99,10 +105,6 @@ public:
 	void Close() noexcept override;
 	List GetList() const noexcept override;
 
-private:
-	/* virtual methods from class ODBus::WatchManagerObserver */
-	void OnDBusClosed() noexcept override;
-
 private:
 	void Insert(UdisksObject &&o) noexcept;
 	void Remove(const std::string &path) noexcept;
@@ -127,10 +129,9 @@ UdisksNeighborExplorer::Open()
 {
 	using namespace ODBus;
 
-	dbus_watch.SetConnection(Connection::GetSystem());
+	dbus_glue.Construct(event_loop);
 
-	auto &connection = dbus_watch.GetConnection();
-	dbus_connection_set_exit_on_disconnect(connection, false);
+	auto &connection = GetConnection();
 
 	try {
 		Error error;
@@ -152,7 +153,7 @@ UdisksNeighborExplorer::Open()
 		pending_list_call = PendingCall::SendWithReply(connection, msg.Get());
 		pending_list_call.SetNotify(OnListNotify, this);
 	} catch (...) {
-		dbus_watch.SetConnection(Connection());
+		dbus_glue.Destruct();
 		throw;
 	}
 }
@@ -169,7 +170,7 @@ UdisksNeighborExplorer::Close() noexcept
 	// TODO: remove_match
 	// TODO: remove_filter
 
-	dbus_watch.SetConnection(Connection());
+	dbus_glue.Destruct();
 }
 
 template<typename I>
@@ -288,12 +289,6 @@ UdisksNeighborExplorer::GetList() const noexcept
 	return result;
 }
 
-void
-UdisksNeighborExplorer::OnDBusClosed() noexcept
-{
-	// TODO: reconnect
-}
-
 void
 UdisksNeighborExplorer::Insert(UdisksObject &&o) noexcept
 {