Add bus.disconnect and service.disconnect

Allow applications to disconnect their connections to dbus after they
are done with them.

Fixes #133

Changes required to make this happen:

* Don't share bus objects: remove the code in lib/dbus.js that stores
created Bus objects and returns them when a new bus is requested.
Instead, create a new Bus object whenever one is requested. This allows
each Bus object to disconnect itself without worrying that other objects
are relying on it being connected. Note that at the C++ level, there is
connection sharing going on because of the use of `dbus_bus_get`, but
that isn't a problem because the dbus library is managing the sharing,
and calling `Bus.prototype.disconnect` will correctly notify the
underlying C++ that that particulary Bus object is no longer using its
connection.

* Remove the `dbus_connection_close` call. According to the
documentation, this method should not be used when a connection is
acquired using `dbus_bus_get`. Removing this prevents the error message
"Applications must not close shared connections - see
dbus_connection_close() docs. This is a bug in the application." noted
in #133. See [dbus_bus_get][1] and [dbus_connection_close][2].

[1]: https://dbus.freedesktop.org/doc/api/html/group__DBusBus.html#ga77ba5250adb84620f16007e1b023cf26
[2]: https://dbus.freedesktop.org/doc/api/html/group__DBusConnection.html#ga2522ac5075dfe0a1535471f6e045e1ee

Author: bryanburgers

README.md

@@ -136,6 +136,12 @@ bus.getInterface('com.example.Library', '/com/example/Library/authors/DAdams', '
 });
 ```
 
+#### `Bus.prototype.disconnect()`
+
+Disconnect from DBus. This disconnection makes it so that Node isn't kept
+running based on this active connection. It also makes this bus, and all of its
+children (interfaces that have been retrieved, etc.) unusable.
+
 
 ### Interface
 
@@ -231,6 +237,13 @@ Remove (or unexpose) an object that has been created.
 service.removeObject(object);
 ```
 
+#### `Service.prototype.disconnect()`
+
+Disconnect from DBus. This disconnection makes it so that Node isn't kept
+running based on this active connection. It also disconnects all of the objects
+created by this service. 
+
+
 ### ServiceObject
 
 An object that is exposed over DBus.

lib/bus.js

@@ -51,6 +51,19 @@ var Bus = module.exports = function(dbus, busName) {
 
 util.inherits(Bus, events.EventEmitter);
 
+Bus.prototype.disconnect = function(callback) {
+	var self = this;
+
+	delete self.dbus.signalHandlers[self.connection.uniqueName];
+
+	self.dbus._dbus.releaseBus(self.connection);
+
+	self.connection = null;
+
+	if (callback)
+		process.nextTick(callback);
+};
+
 Bus.prototype.reconnect = function(callback) {
 	var self = this;
 

lib/dbus.js

@@ -6,7 +6,6 @@ var Utils = require('./utils');
 var Bus = require('./bus');
 var Service = require('./service');
 
-var busMap = {};
 var serviceMap = {};
 
 var enabledSignal = false;
@@ -41,14 +40,7 @@ DBus.Signature = Utils.Signature;
 DBus.prototype.getBus = function(busName) {
 	var self = this;
 
-	// Return bus existed
-	if (busMap[busName])
-		return busMap[busName];
-
-	var bus = new Bus(self, busName);
-	busMap[busName] = bus;
-
-	return bus;
+	return new Bus(self, busName);
 };
 
 DBus.prototype.parseIntrospectSource = function(source) {

lib/service.js

@@ -39,3 +39,9 @@ Service.prototype.removeObject = function(object) {
 
 	self.bus.dbus._dbus.unregisterObjectPath(self.bus.connection, object.path);
 };
+
+Service.prototype.disconnect = function() {
+	var self = this;
+
+	self.bus.disconnect();
+};

src/connection.cc

@@ -274,9 +274,6 @@ namespace Connection {
 
 		uv_unref((uv_handle_t *)bus->loop);
 
-		if (dbus_connection_get_is_connected(connection))
-			dbus_connection_close(connection);
-
 		dbus_connection_unref(connection);
 	}
 

test/client-disconnect.test.js

@@ -0,0 +1,16 @@
+var tap = require('tap');
+var DBus = require('../');
+
+var dbus = new DBus();
+var bus = dbus.getBus('session');
+
+tap.plan(1);
+
+var timeout = setTimeout(function() {
+	tap.fail('Should have disconnected by now');
+	process.exit();
+}, 1000);
+timeout.unref();
+
+tap.ok('This is a dummy test. The real test is whether the tap.fail gets called on the timeout.');
+bus.disconnect();

test/service-client-disconnect.test.js

@@ -0,0 +1,26 @@
+var tap = require('tap');
+var DBus = require('../');
+
+tap.plan(1);
+
+var dbus = new DBus();
+var client = dbus.getBus('session');
+
+var timeout = setTimeout(function() {
+	tap.fail('Should have disconnected by now');
+	process.exit();
+}, 1000);
+timeout.unref();
+
+tap.ok('This is a dummy test. The real test is whether the tap.fail gets called on the timeout.');
+setTimeout(function() {
+	client.disconnect();
+}, 50);
+
+setTimeout(function() {
+	var service = dbus.registerService('session', 'test.dbus.TestService');
+	service.createObject('/test/dbus/TestService');
+	setImmediate(function() {
+		service.disconnect();
+	});
+}, 100);

test/service-disconnect.test.js

@@ -0,0 +1,19 @@
+var tap = require('tap');
+var DBus = require('../');
+
+tap.plan(1);
+
+var dbus = new DBus();
+var service = dbus.registerService('session', 'test.dbus.TestService');
+service.createObject('/test/dbus/TestService');
+
+var timeout = setTimeout(function() {
+	tap.fail('Should have disconnected by now');
+	process.exit();
+}, 1000);
+timeout.unref();
+
+tap.ok('This is a dummy test. The real test is whether the tap.fail gets called on the timeout.');
+setTimeout(function() {
+	service.disconnect();
+}, 50);