ThreadedSocketService

A ThreadedSocketService is a simple subclass of SocketService that handles incoming connections by creating a worker thread and dispatching the connection to it by emitting the run signal in the new thread.

The signal handler may perform blocking IO and need not return until the connection is closed.

The service is implemented using a thread pool, so there is a limited amount of threads available to serve incoming requests. The service automatically stops the SocketService from accepting new connections when all threads are busy.

As with SocketService, you may connect to run, or subclass and override the default handler.

Example: Threaded socket service:

public class Source : Object {
	public uint16 port { private set; get; }

	public Source (uint16 port) {
		this.port = port;
	}
}

public static int main (string[] args) {
	MainLoop loop = new MainLoop ();

	// Create a new SocketService:
	ThreadedSocketService service = new ThreadedSocketService (10);

	try {
		// Listen on port 1024 and 1025.
		// Source is used as source-identifier.
		service.add_inet_port (1024, new Source (1024));
		service.add_inet_port (1025, new Source (1025));
	} catch (Error e) {
		print ("Error: %s\n", e.message);
		return 0;
	}

	// Used to shutdown the program:
	Cancellable cancellable = new Cancellable ();
	cancellable.cancelled.connect (() => {
		service.stop ();
		loop.quit ();
	});

	// The run signal is emitted in a worker thread:
	service.run.connect ((connection, source_object) => {
		try {
			Source source = source_object as Source;
			print ("Accepted! (Source: %d)\n", source.port);

			DataInputStream istream = new DataInputStream (connection.input_stream);
			DataOutputStream ostream = new DataOutputStream (connection.output_stream);

			// Get the received message:
			string message = istream.read_line (null, cancellable);
			message._strip ();
			print ("Received: %s\n", message);

			// Response:
			ostream.put_string (message, cancellable);
			ostream.put_byte ('\n', cancellable);

			if (message == "shutdown") {
				cancellable.cancel ();
				return true;
			}
		} catch (Error e) {
			print ("Error: %s\n", e.message);
		}
		return false;
	});

	service.start ();
	loop.run ();
	return 0;
}

valac --pkg gio-2.0 GLib.ThreadedSocketService.vala